阅读说明：本技术 形成受保护连接的方法以及包括该连接的连接器 (Method of forming a protected connection and connector including the connection ) 是由 戴尔文·埃文斯 弗雷德·霍珀 A·麦克劳德 G·哈伯德 内尔·波尔特 于 2019-03-13 设计创作，主要内容包括：一种在任选地安装在支架(202)上的第一连接元件与第二连接元件之间形成受保护连接的方法,该方法包括：(i)在该第一连接元件和/或该支架上沉积保护性材料(210)；(ii)任选地在保护性材料上沉积覆盖涂层(212)；以及(iii)推动该第二连接元件并在该第一连接元件与该第二连接元件之间建立连接,该连接由该保护性材料保护。(A method of forming a protected connection between a first connection element and a second connection element, optionally mounted on a bracket (202), the method comprising: (i) depositing a protective material (210) on the first connection element and/or the holder; (ii) optionally depositing a cover coat (212) over the protective material; and (iii) pushing the second connection element and establishing a connection between the first connection element and the second connection element, the connection being protected by the protective material.)

1. A method of forming a protected connection between a first connection element and a second connection element, optionally mounted on a stent, the method comprising:

(i) depositing a protective material on the first connection element and/or the stent;

(ii) optionally depositing a cover coat over the protective material; and

(iii) pushing the second connection element and establishing a connection between the first connection element and the second connection element, the connection being protected by the protective material.

2. The method of claim 1, wherein step (iii) additionally comprises pushing the second connecting element into the protective material.

3. The method of claim 1 or 2, wherein step (iii) additionally comprises pushing the second connection element through the covercoat.

4. The method of any one of the preceding claims, wherein in step (i), the protective material is deposited on the first connection element.

5. The method of any one of the preceding claims, wherein in step (iii), the second connection element is pushed into the protective material and optionally through the cover coating to establish a connection between the first connection element and the second connection element.

6. The method of any one of the preceding claims, wherein the support is a printed circuit board.

7. The method of any one of the preceding claims, comprising:

(i) depositing a protective material on the first connection element;

(ii) optionally depositing a cover coat over the protective material; and

(iii) pushing the second connection element into the protective material and optionally through the cover coat to establish a connection between the first connection element and the second connection element, the connection being protected by the protective material.

8. The method of any one of the preceding claims, wherein the protective material is a self-healing material.

9. The method of any one of the preceding claims, wherein the protective material is a gel.

10. The method of any one of the preceding claims, wherein the protective material has a hardness value of less than 100 according to shore OO hardness as determined by ASTM D2240.

11. The method of any one of the preceding claims, wherein the protective material has a hardness value of 1mm/10 or greater according to the penetration hardness scale as determined by ISO 2137, 9.38g hollow cone.

12. The method of any one of the preceding claims, wherein depositing the protective material comprises using a base material, optionally comprising silicone rubber, and a catalyst, optionally comprising platinum.

13. The method of any preceding claim, wherein depositing the protective material comprises curing, optionally UV curing and/or thermal curing.

14. The method of claim 12 or 13, wherein the viscosity of the mixture of the base material and the catalyst is from 100cPs to 400,000 cPs.

15. The method of any one of the preceding claims, wherein the connection is an electrical connection.

16. The method of claim 15, wherein the first and second connection elements constitute an electrical connector, and the electrical connector is selected from the group consisting of: electrical connectors including spring-loaded contacts, electrical connectors having contacts including spring-loaded pins, poke-in electrical connectors, contact pads, board-to-board (B2B) connectors, and Zero Insertion Force (ZIF) connectors.

17. A method according to any preceding claim, wherein the method includes the step of (ii) depositing a cover coat over the protective material.

18. A method according to any preceding claim, wherein depositing the cover coat in step (ii) comprises forming a plasma deposited layer.

19. The method of claim 18, wherein depositing the overcoat layer in step (ii) comprises exposing the protective material to a plasma comprising a monomeric compound for a period of time sufficient to allow the overcoat layer to form.

20. The method of claim 19, wherein,

the monomeric compound is a compound of formula (I):

wherein

R¹、R²And R⁴Each of which is independently selected from hydrogen, halogen, optionally substituted branched or straight chain C₁-C₆Alkyl, optionally substituted C₃-C₈Cycloalkyl, optionally substituted C₃-C₁₂Aryl radical, and

R³selected from:

wherein each X is independently selected from hydrogen, halogen, optionally substituted branched or straight chain C₁-C₆Alkyl, optionally substituted C₃-C₈Cycloalkyl and optionally substituted C₃-C₁₂Aryl radical, and

n is an integer from 1 to 27.

21. The method of claim 19 or 20, wherein the monomeric compound is a compound of formula (Ia):

wherein

R¹、R²、R⁴And R⁵To R¹⁰Each of which is independently selected from hydrogen and optionally substituted C₁-C₆Branched or straight chain alkyl;

each X is independently selected from hydrogen and halogen;

a is from 0 to 10; b is from 2 to 14; and c is 0 or 1;

or

Wherein the monomeric compound is a compound of formula (Ib):

wherein

R¹、R²、R⁴And R⁵To R¹⁰Each of which is independently selected from hydrogen and optionally substituted C₁-C₆Branched or straight chain alkyl;

each X is independently selected from hydrogen and halogen;

a is from 0 to 10; b is from 2 to 14; and c is 0 or 1.

22. The method of claim 21, wherein a and c are each independently 0 or 1; and b is from 3 to 7.

23. The method of any one of claims 20 to 22, wherein each X is F.

24. The method of any one of claims 20-23, wherein R¹、R²And R⁴Each of which is independently selected from hydrogen and methyl.

25. The method of claim 24, wherein R¹、R²And R⁴Each of which is hydrogen.

26. The method of any one of claims 21-25, wherein R⁵To R¹⁰Each of which is independently selected from hydrogen and methyl.

27. The method of claim 26, wherein R⁵To R¹⁰Each of which is hydrogen.

28. The method of any one of claims 20 to 27, wherein the monomeric compound is a compound of formula (Ic):

wherein m is from 1 to 10.

29. The process of claim 28, wherein the compound of formula (Ic) is selected from the group consisting of 1H, 2H-perfluorohexyl acrylate, 1H, 2H-perfluorooctyl acrylate, 1H, 2H-perfluorodecyl acrylate, and 1H, 2H-perfluorododecyl acrylate.

30. The method of any one of claims 20 to 27, wherein the monomer compound is a compound of formula (Id):

wherein m is from 1 to 10.

31. The method of claim 30, wherein the compound of formula (Id) is selected from the group consisting of 1H, 2H-perfluorohexyl methacrylate, 1H, 2H-perfluorooctyl methacrylate, and 1H, 2H-perfluorodecyl methacrylate.

32. The method of any one of claims 19 to 31, wherein in step (ii), the protective material is exposed to a plasma comprising the monomeric compound and a cross-linking agent.

33. The method of claim 32, wherein the crosslinker comprises two or more unsaturated bonds attached through one or more linker moieties.

34. The method of claim 32 or 33, wherein the cross-linking agent has a boiling point of less than 500 ℃ at standard pressure.

35. The method of any one of claims 32 to 34, wherein the cross-linking agent is independently selected from compounds of formula (II) or (III):

wherein

Y¹、Y²、Y³、Y⁴、Y⁵、Y⁶、Y⁷And Y⁸Each independently selected from hydrogen, optionally substituted branched or straight chain C₁-C₆Alkyl, optionally substituted C₁-C₆Cycloalkyl and optionally substituted C₁-C₆An aryl group; and is

L is a linker moiety.

36. The method of claim 35, wherein for the compound of formula (II), group L has the formula:

wherein

Each Y⁹Independently selected from the group consisting of a bond, -O-C (O) -, -O-, -Y¹¹-O-C(O)-、-C(O)-O-Y¹¹-、-OY¹¹-and-Y¹¹O-in which Y¹¹Is optionally substituted branched, straight or cyclic C₁-C₈An alkylene group; and is

Y¹⁰Selected from optionally substituted branched, straight or cyclic C₁-C₈Alkylene radicalAnd a siloxane group.

37. The method of any one of claims 32 to 36, wherein the crosslinking agent is independently selected from divinyl adipate, 1, 4-butanediol divinyl ether, 1, 4-cyclohexanedimethanol divinyl ether, 1, 7-octadiene, 1,2, 4-trivinylcyclohexane, 1, 3-divinyltetramethyldisiloxane, diallyl 1, 4-cyclohexanedicarboxylate, 1, 6-divinylperfluorohexane, 1H, 6H-perfluorohexanediol diacrylate, and glyoxalbis (diallyl acetal).

38. The method of claim 37, wherein the crosslinking agent is divinyl adipate (DVA).

39. The process according to any one of claims 35 to 38, wherein, for the compound of formula (III), the group L is selected from branched or linear C₁-C₈Alkylene or ether groups.

40. The method of any one of claims 32 to 39, wherein in step (ii), the monomer compound and the cross-linking agent are introduced into the plasma deposition chamber in a liquid phase and the volume ratio of the cross-linking agent to the monomer compound is from 1:99 to 20: 80.

41. The method of claim 40, wherein in step (ii), the volume ratio of the cross-linking agent to the monomer compound is from 5:95 to 15: 85.

42. The method of any one of claims 32 to 41, wherein in step (ii), the monomer compound and the cross-linking agent are introduced into a plasma deposition chamber and the molar input flow ratio of the cross-linking agent to the monomer compound is from 1:20 to 1: 1.

43. The process of claim 42, wherein in step (ii), the molar input flow ratio of the cross-linking agent to the monomer compound is from 1:14 to 1: 6.

44. The method of any one of the preceding claims, wherein the protective material has a thickness of from 0.1mm to 5 mm.

45. The method of any one of the preceding claims, wherein the thickness of the cover coat is from 250nm to 10000 nm.

46. The method of any one of the preceding claims, wherein the method further comprises depositing one or more additional coatings.

47. The method of any one of the preceding claims, wherein the second connection element is not coated.

48. The method of any one of claims 1 to 47, wherein the method further comprises depositing the protective material and optionally the cover coat on the second connection element prior to performing the connection in step (iii).

49. The method of any one of the preceding claims, wherein the joining between the first and second connection elements in step (iii) comprises stamping the protective material and optionally the cover coat prior to the joining.

50. A protected connection obtainable by the method of any one of claims 1 to 49.

51. A connector comprising first and second connection elements forming a connection, the connection being protected by a dot of protective material with an overlying coating, optionally wherein a portion of the protective material is interposed between the connection elements.

52. The connector of claim 51, said connector being an electrical connector.

53. The connector of claim 52, wherein the connector is selected from the electrical connectors defined in claim 10.

54. A connector according to any one of claims 51 to 53, wherein the protective material is as defined in any one of claims 8 to 11 or 44.

55. A connector according to any of claims 51 to 54, wherein the protective material is obtainable by deposition as defined in any of claims 1 or 7 to 14.

56. The connector of any of claims 51-55, wherein the covercoat comprises a plasma deposited layer.

57. A connector according to any one of claims 51 to 56, wherein the covercoat is obtainable by deposition as defined in any one of claims 18 to 43.

58. A connector as claimed in any one of claims 51 to 57, wherein the covercoat is as defined in claim 45.

Technical Field

The invention relates to a method of forming a protected connection between a first connection element and a second connection element, a protected connection obtainable by the method, and a connector.

Background

It is well known that electronic and electrical equipment is very sensitive to damage caused by contamination by liquids, such as environmental liquids, in particular water. Contact with liquids during normal use or due to accidental exposure may result in short circuits between electronic components and irreparable damage to circuit boards, electronic chips, etc.

This problem is particularly acute with small portable electronic devices such as mobile phones, smart phones, pagers, radios, hearing aids, laptop computers, notebook computers, tablet phones and Personal Digital Assistants (PDAs), which may be exposed to significant liquid contamination when used indoors or outdoors in close proximity to liquids. Such devices are also prone to accidental exposure to liquids, for example if dropped into a liquid or splashed.

Other types of electronic or electrical equipment may be easily damaged, primarily because of their location, such as outdoor lighting systems, radio antennas, and other forms of communication equipment.

It is known in the art that there are particular difficulties in applying protective coatings to electronic substrates. In principle, the electronic substrate may be any electronic or electrical device or component comprising at least one exposed electrical or electronic contact point. Such substrates are particularly fragile (e.g., in view of electrochemical migration) and often require highly effective barriers and protection from liquids on complex surfaces (e.g., circuit board topography).

It is well known to apply conformal coatings to electronic or electrical devices to protect moisture, dust, chemicals and temperature extremes by wet chemical techniques such as brushing, spraying and dipping. Conformal coatings take the 3D shape of the substrate on which they are formed and cover the entire surface of the substrate. For example, it is known to apply relatively thick protective coatings on electronic substrates based on parylene technology. The conformal coating formed in this way typically has a thickness of 30-130 μm for acrylic, epoxy or urethane resins and 50-210 μm for silicone.

The use of wet chemical techniques to form these coatings has the disadvantage of requiring the use of solvents and the associated environmental impact. Furthermore, wet chemical techniques only allow for coating of exposed areas of a device or component, so "hidden" areas (e.g., recesses behind the component) may be left unprotected. Examples of such hidden areas on a mobile phone include areas under the inner parts of an RF shield, a screen FOG (flexible glass) connector, a ZIF (zero insertion force) connector.

Furthermore, if coated with an excessively thick protective layer, the electrical or electronic contact points of such substrates may lose their function due to the increase in electrical resistance.

Since the conformal coating formed by wet chemical techniques is relatively thick, the contact points are typically masked to prevent deposition of the coating thereon. However, this results in complex processing that is impractical on an industrial scale. In addition, relatively thick coatings may cause clogging in areas such as rotating shafts. An alternative method of protecting electronic and electrical devices is the splatter-proof (TM) technique of P2i, in which an ultra-thin protective coating is applied on both the outside and the inside of the assembled electronic or electrical device. This limits liquid ingress while additionally preventing any ingress liquid from spreading within the device. Thus, the majority of the liquid challenge is prevented from entering the device in the first place, while there is some additional protection within the device that does not interfere with the function of the contact points. However, since this technique is directed to liquid-proof coatings and not physical barriers, it generally provides protection only against splatter and not against immersion of the device in liquid.

WO2007/083122 discloses electronic and electrical devices having a liquid-repellent polymeric coating formed thereon by exposure to a pulsed plasma comprising a particular monomeric compound for a period of time sufficient to allow a polymeric layer to form on the surface of the electrical or electronic devices. Typically, the article to be treated is placed in a plasma chamber together with the material to be deposited in the gaseous state, a glow discharge is ignited in the chamber and a suitable voltage (which may be a pulsed voltage) is applied.

WO2016/198857 discloses an electronic or electrical device comprising a crosslinked polymer coating on a surface thereof, wherein the crosslinked polymer coating is obtainable by exposing the device to a plasma comprising a specific monomer compound and a crosslinking agent having specific properties for a period of time sufficient to allow formation of the crosslinked polymer coating on the surface of the device.

There remains a need in the art for highly effective protective coatings without the drawbacks of coatings applied by prior art methods. Such coatings may further enhance the resistance of the substrate to liquids, enhance durability, and/or enable more efficient manufacture of the protected substrate, particularly in the electronics industry. It is an object of the present invention to provide a solution to this problem and/or at least one other problem associated with the prior art.

Disclosure of Invention

A first aspect of the invention provides a method of forming a protected connection between a first connection element, optionally mounted on a support, and a second connection element, the method comprising: (i) depositing a protective material on the first connection element and/or the holder; (ii) optionally depositing a cover coat over the protective material; and (iii) pushing the second connection element and establishing a connection between the first connection element and the second connection element, the connection being protected by the protective material.

Advantageously, the protective material is deposited in such a way that the action for establishing the connection can also establish the protection of the connection by the protective material.

Step (iii) may comprise pushing the second connection element into the protective material. This may be done sequentially or simultaneously to establish the connection. When performed sequentially, the second connection element may be pushed into the protective material and the connection is then established, or the connection may be established and the second connection element is then pushed into the protective material.

Step (iii) comprises pushing the second connection element and establishing a connection between the first connection element and the second connection element. This step generally comprises pushing the second connection element to establish a connection between the first connection element and the second connection element.

The method can include depositing a covercoat over the protective material. In this case, step (iii) may comprise pushing the second connection element through the cover coating.

In a preferred embodiment, in step (i), a protective material is deposited on the first connection element.

In an embodiment, in step (iii), the second connection element is pushed into the protective material and optionally through the cover coating to establish a connection between the first connection element and the second connection element.

A preferred embodiment provides a method of forming a protected connection between a first connection element and a second connection element, the method comprising:

(i) depositing a protective material over the first connection element;

(ii) optionally depositing a cover coat over the protective material; and

(iii) a second connection element is pushed into the protective material and optionally through the cover coat to establish a connection between the first connection element and the second connection element, the connection being protected by the protective material.

The protective material may provide protection from liquids, dust or mechanical damage, while it may also act as a fixative to fix the connection.

A protective material may encapsulate the connection. This may mean that the protective material covers the entire surface or substantially the entire surface of the connection. In an embodiment, a protective material may be sealed around the connection. In an embodiment, the protective material covers enough of the surface of the connection to protect it from liquids, dust and/or mechanical damage.

In one embodiment, the second connection element is pushed into the protective material. This may mean that the second connection element pierces the surface of the protective material and penetrates the protective material. Alternatively, this may mean that the second connecting element is pressed against the protective material such that the second connecting element occupies the area of space that would otherwise be occupied by the protective material, for example by pushing a dent, recess or groove into the protective material. In this sense, the second connecting element has been pushed into the spatial region that would otherwise be occupied by the protective material. In this embodiment, the protective material will be resiliently biased against the second connection element. This resilient bias may serve to protect the connection.

The connection is protected by a protective material. In a particularly preferred embodiment, the protective material forms a waterproof seal around the connection when the connection is made. Advantageously, this prevents the ingress of water which could damage the connection.

In an embodiment, the protective material may be a self-healing material. "self-healing" refers to the ability of a material to regenerate or repair itself in the event that damage persists, for example because new bonds form spontaneously when old bonds within the material break. Typically, when the self-healing material is damaged (e.g., by pushing the second connecting element through the material), this will activate the self-healing process, including the chemical repair process. For example, the chemical repair process may be based on polymerization, entanglement, or cross-linking, wherein the cross-linking may optionally be reversible.

In an embodiment, the protective material may be a gel. As is well known in the art, a gel is a non-fluid colloidal or polymeric network that is expanded throughout its volume by a fluid.

In an embodiment, the gel comprises a self-healing gel.

In an embodiment, the protective material has a hardness value of 40 or less according to shore a hardness as determined by ASTM D2240. Optionally, the protective material has a hardness value of 35 or less, 30 or less, 25 or less, 20 or less, 15 or less, or 10 or less, in terms of shore a hardness.

In an embodiment, the protective material has a hardness value of less than 100 according to shore OO hardness as determined by ASTM D2240. Optionally, the protective material has a hardness value of 90 or less, 80 or less, 70 or less, 60 or less, 50 or less, 40 or less, 30 or less, 20 or less, or 10 or less, in terms of shore OO hardness. In an embodiment, the protective material has a hardness value of less than 10 on the shore OO hardness scale.

In an embodiment, the protective material has a hardness value of 1mm/10 or greater according to the penetration hardness scale as determined by ISO 2137, 9.38g hollow cone. (for this measurement method, a larger number indicates a softer material.) optionally, the protective material has a hardness of 30mm/10 or more, 40mm/10 or more, 50mm/10 or more, 60mm/10 or more, 70mm/10 or more, 80mm/10 or more, 90mm/10 or more, 100mm/10 or more, 110mm/10 or more, 120mm/10 or more, 130mm/10 or more, 140mm/10 or more, 150mm/10 or more, or 160mm/10 or more, according to the osmotic hardness scale as determined by ISO 2137, 9.38g hollow cone.

In an embodiment, the dielectric strength of the protective material is greater than 5kV/mm, preferably greater than 10 kV/mm.

In an embodiment, depositing the protective material comprises curing, optionally UV curing and/or thermal curing. The thermal curing may be carried out at room temperature or at elevated temperatures above room temperature. For example, thermal curing can be carried out at a temperature greater than 30 ℃, 40 ℃, 50 ℃, 60 ℃, 70 ℃, 80 ℃ or 90 ℃. In particular, the thermal curing may be carried out at a temperature between 30 ℃ and 100 ℃, between 40 ℃ and 90 ℃, between 50 ℃ and 80 ℃ or between 60 ℃ and 70 ℃. In a preferred embodiment, the thermal curing is performed at room temperature, e.g., 10 ℃ to 30 ℃, 15 ℃ to 25 ℃, or 18 ℃ to 22 ℃, such as at about 17 ℃, 18 ℃, 19 ℃, 20 ℃, 21 ℃, 22 ℃, 23 ℃, or 24 ℃.

In an embodiment, depositing the protective material includes using a base material and a catalyst. In an embodiment, the base material comprises a curable silicon prepolymer and/or a silicon rubber, such as a vinyl-containing polysiloxane and/or a hydrogenated siloxane-containing polysiloxane. In embodiments, the catalyst comprises a hydrosilylation initiator or catalyst. In an embodiment, the catalyst comprises platinum. The mixing ratio between the base material and the catalyst can be easily determined by those skilled in the art. For example, the mixing ratio between the base material and the catalyst may be from 20:1 to 1:1 by volume. In embodiments, the mixing ratio is from 1:15 to 1:5, or about 10:1, by volume.

The viscosity of the base material prior to curing may be from 50cPs to 400,000cPs, for example from 1000cPs to 200,000cPs, or from 10,000cPs to 100,000cPs, or about 55,000cPs at 23 ℃.

In embodiments, the viscosity of the base material prior to curing is 50cPs, 100cPs, 200cPs, 500cPs, 1000cPs, 10,000cPs, 20,000cPs, 30,000cPs, 40,000cPs, or 50,000cPs, and/or the viscosity of the base material prior to curing is up to 400,000cPs, 300,000cPs, 200,000cPs, 100,000cPs, 90,000cPs, 80,000cPs, 70,000cPs, 60,000cPs, or 50,000 cPs.

The viscosity of the catalyst prior to curing may be from 50cPs to 400,000cPs, for example from 500cPs to 200,000cPs, or from 750cPs to 100,000cPs, or about 1,000cPs at 23 ℃.

In embodiments, the viscosity of the catalyst prior to curing is 50cPs, 100cPs, 200cPs, 500cPs, 750cPs or 1000cPs, and/or the viscosity of the catalyst prior to curing is up to 400,000cPs, 300,000cPs, 200,000cPs, 100,000cPs, 90,000cPs, 80,000cPs, 70,000cPs, 60,000cPs, 50,000cPs, 40,000cPs, 30,000cPs, 20,000cPs, 10,000cPs, 5000cPs, 4000cPs, 3000cPs, 2000cPs or 1000 cPs.

The viscosity of the mixture of base material and catalyst prior to curing may be from 50cPs to 400,000cPs, for example from 50cPs to 400,000cPs, or about 42,000cPs at 23 ℃.

In embodiments, the viscosity of the mixture of base material and catalyst prior to curing is 50cPs, 100cPs, 200cPs, 500cPs, 1000cPs, 10,000cPs, 20,000cPs, 30,000cPs, 40,000cPs or 50,000cPs, and/or the viscosity of the mixture of base material and catalyst prior to curing is up to 400,000cPs, 300,000cPs, 200,000cPs, 100,000cPs, 90,000cPs, 80,000cPs, 70,000cPs, 60,000cPs, 50,000cPs or 45,000 cPs.

In an embodiment, the protective material is deposited as a plurality of discrete units.

In an embodiment, the protective material is deposited directly on the first connection element.

In the method according to the first aspect of the invention, a connection is established between the first connection element and the second connection element. The connection is thus an interface between the first connection element and the second connection element. The first connection element and the second connection element may constitute a connector. Thus, the connection may be a connector interface.

The connection may be an electrical connection. The first connection element and the second connection element may constitute an electrical connector. In the case of an electrical connection, the protective material protects the conductive surfaces of the connection (i.e., the conductive surfaces of the first and second connection elements). In other words, the conductive surface is protected from exposure to water or other contaminants. For example, where the connection element is an insulated wire having an insulated portion removed to expose the conductive core, the protective material protects the connection and any remaining exposed conductive core. In certain embodiments, in which insulation is removed on only one side of the wire, the exposed core may be protected by pushing it against (i.e., into but not piercing or penetrating) the protective material deposit.

In an embodiment, the electrical connector is selected from the following: electrical connectors including spring-loaded contacts, electrical connectors having contacts including spring-loaded pins, poke-in electrical connectors, contact pads, board-to-board (B2B) connectors, and Zero Insertion Force (ZIF) connectors. Preferably, the electrical connector is selected from the following: spring connectors, contact pads, board-to-board (B2B) connectors, and Zero Insertion Force (ZIF) connectors.

In an embodiment of the invention, the electrical connector and/or the first connection element form part of or are present on an electronic component, such as a Printed Circuit Board (PCB), a Printed Circuit Board Array (PCBA), a transistor, a resistor or a semiconductor chip. The electronic component may be an internal component of an electronic device, such as a mobile phone.

In an embodiment, the method according to the first aspect of the invention comprises the step (ii) of depositing a cover coat on the protective material. For example, the overlay coating may be deposited by plasma deposition, by Chemical Vapor Deposition (CVD), or by wet chemical techniques such as brushing, spraying, and dipping. The overlay coating may be, for example, a plasma deposited coating, a CVD coating, or a spray coating. In an embodiment, the cover coating may be a parylene coating.

In an embodiment, depositing the covercoat in step (ii) comprises forming a plasma deposited layer.

In an embodiment, depositing the covercoat in step (ii) includes exposing the protective material to a plasma including a monomeric compound for a period of time sufficient to allow the covercoat to form.

Surprisingly, the use of a protective material under the plasma deposited layer allows the second connection element to be pushed through the protective material and the plasma deposited layer while maintaining the desired coating properties (such as its water-resistant properties). No unmasking step is required and the connecting elements are protected from corrosion. Furthermore, there is no need to handle the second connection element separately in order to establish a protected connection.

In an embodiment, the monomeric compound is a compound of formula (I):

wherein

R¹、R²And R⁴Each of which is independently selected from hydrogen, halogen, optionally substituted branched or straight chain C₁-C₆Alkyl, optionally substituted C₃-C₈Cycloalkyl, optionally substituted C₃-C₁₂Aryl radical, and

R³selected from:

wherein each X is independently selected from hydrogen, halogen, optionally substituted branched or straight chain C₁-C₆Alkyl, optionally substituted C₃-C₈Cycloalkyl and optionally substituted C₃-C₁₂Aryl radical, and

n is an integer from 1 to 27.

Throughout this specification, unless explicitly stated otherwise:

- "optionally substituted" groups may be unsubstituted or substituted by one or more (e.g. one or two) substituents. For example, these substituents may be selected from alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, and heterocyclyl groups; carboxylic acid and carboxylate ions; a carboxylic acid ester; a carbamate; an alkoxy group; ketone and aldehyde groups; amine and amide groups; -OH; -CN; -NO₂(ii) a And a halogen.

Alkyl groups may be straight or branched chain alkyl groups. The alkyl group may be C₁To C₆Alkyl, or C₁To C₅Alkyl, or C₁To C₄Alkyl, or C₁To C₃Alkyl, or C₁To C₂An alkyl group. For example, alkyl may be selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, n-pentyl, neopentyl, n-hexyl, isohexyl and 3-methylpentyl.

Cycloalkyl may be C₃To C₈Cycloalkyl radical, C₃To C₇Cycloalkyl radical, C₃To C₆Cycloalkyl radical, C₄To C₆Cycloalkyl or C₅To C₆A cycloalkyl group.

Aryl may be monocyclic or bicyclic aryl. The aryl group may contain from 3 to 12 carbon atoms. Aryl may be C₃To C₁₂Aryl radical, C₅To C₁₂Aryl radical, C₅To C₁₀Aryl radical, C₅To C₈Aryl or C₅To C₆And (4) an aryl group.

The halogen group can be fluorine (F), chlorine (Cl), bromine (Br) or iodine (I), preferably fluorine (F).

In the examples, R¹、R²And R⁴Each of which is independently selected from hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, n-pentyl, neopentyl, n-hexyl, isohexyl and 3-methylpentyl. In the examples, R¹、R²And R⁴Each of which is independently selected from hydrogen and methyl. In the examples, R¹And R²Are all hydrogen. In the examples, R⁴Is methyl. In the examples, R¹、R²And R⁴Each of which is hydrogen.

In an embodiment, each X is independently selected from hydrogen, halogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, n-pentyl, neopentyl, n-hexyl, isohexyl, and 3-methylpentyl. In embodiments, each of X is independently selected from hydrogen and halogen. In embodiments, each X is hydrogen. In embodiments, each X is halogen. In an embodiment, each X is F.

n is an integer from 1 to 27. In embodiments, the lower value of the possible range for n is 1,2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, or 26, and/or the upper value of the possible range for n is 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, or 2.

In an embodiment, the monomeric compound is a compound of formula (Ia):

wherein

R¹、R²、R⁴And R⁵To R¹⁰Each of which is independently selected from hydrogen and optionally substituted C₁-C₆Branched or straight chain alkyl;

each X is independently selected from hydrogen and halogen;

a is from 0 to 10; b is from 2 to 14; and c is 0 or 1.

In an embodiment, the monomeric compound is a compound of formula (Ib):

wherein

R¹、R²、R⁴And R⁵To R¹⁰Each of which is independently selected from hydrogen and optionally substituted C₁-C₆Branched or straight chain alkyl;

each X is independently selected from hydrogen and halogen;

a is from 0 to 10; b is from 2 to 14; and c is 0 or 1.

In the examples, R¹、R²、R⁴And R⁵To R¹⁰Each of which is independently selected from hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, n-pentyl, neopentyl, n-hexyl, isohexyl and 3-methylpentyl.

In the examples, R¹、R²And R⁴Each of which is independently selected from hydrogen and methyl. In the examples, R¹And R²Are all hydrogen. In the examples, R⁴Is methyl. In the examples, R¹、R²And R⁴Each of which is hydrogen.

In the examples, R⁵To R¹⁰Each of which is independently selected from hydrogen and methyl.

In the examples, R⁵And R⁶Is hydrogen. In the examples, R⁵、R⁶、R⁷And R⁸Is hydrogen. In the examples, R⁵To R¹⁰Each of which is hydrogen.

In an embodiment, each X is independently selected from hydrogen, halogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, n-pentyl, neopentyl, n-hexyl, isohexyl, and 3-methylpentyl. In embodiments, each of X is independently selected from hydrogen and halogen. In embodiments, each X is hydrogen. In embodiments, each X is halogen. In an embodiment, each X is F.

a is an integer from 0 to 10. In embodiments, the lower value of the possible range of a is 0, 1,2, 3, 4, 5, 6, 7, 8, or 9, and/or the upper value of the possible range of a is 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1.

b is an integer from 2 to 14. In an embodiment, the lower value of the possible range of b is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 or 13 and/or the upper value of the possible range of b is 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4 or 3.

In an embodiment, c is 0. In an embodiment, c is 1.

In an embodiment, a and c are each 0.

In embodiments, a and c are each independently 0 or 1; and b is from 3 to 7.

In an embodiment, p ═ a + b + c + 1; a and c are each independently 0 or 1; b is from 3 to 7 and p is from 4 to 10.

In an embodiment, the monomeric compound is a compound of formula (Ic):

wherein m is from 1 to 10.

m is an integer from 0 to 10. In embodiments, the lower value of the possible range of m is 0, 1,2, 3, 4, 5, 6, 7, 8, or 9, and/or the upper value of the possible range of m is 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1.

In an embodiment, the compound of formula (Ic) is selected from 1H,1H,2H, 2H-perfluorohexyl acrylate (PFAC4), 1H,2H, 2H-perfluorooctyl acrylate (PFAC6), 1H,2H, 2H-perfluorodecyl acrylate (PFAC8) and 1H,1H,2H, 2H-perfluorododecyl acrylate (PFAC 10).

In an embodiment, the monomeric compound used to form the coating X is a compound of formula (Id):

wherein m is from 1 to 10.

m is an integer from 0 to 10. In embodiments, the lower value of the possible range of m is 0, 1,2, 3, 4, 5, 6, 7, 8, or 9, and/or the upper value of the possible range of m is 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1.

In an embodiment, the compound of formula (Id) is selected from 1H,1H,2H, 2H-perfluorohexyl methacrylate (PFMAC4), 1H,2H, 2H-perfluorooctyl methacrylate (PFMAC6) and 1H,1H,2H, 2H-perfluorodecyl methacrylate (PFMAC 8).

In an embodiment, the monomeric compound is a compound of formula (Ie):

wherein R is⁴、R¹⁰A, b and c are as described above.

In an embodiment, q ═ a + b + c + 1; a and c are each independently 0 or 1; b is from 3 to 7 and q is from 4 to 10.

In an embodiment, the monomeric compound is a compound of formula (If):

wherein m is from 2 to 12.

In an embodiment, the monomer compound may be selected from the group consisting of ethylhexyl acrylate, hexyl acrylate, decyl acrylate, lauryl dodecyl acrylate, and isodecyl acrylate.

In an embodiment, the monomeric compound is a compound of formula (Ig):

wherein R is¹、R²And R⁴Is as described above, and m is from 4 to 14.

In an embodiment, the monomeric compound is a compound of formula (Ih):

wherein m is from 4 to 14.

In an embodiment, in step (ii), the protective material is exposed to a plasma comprising a monomeric compound and a crosslinking agent.

In embodiments, the crosslinker comprises two or more unsaturated bonds attached through one or more linker moieties.

In an embodiment, the crosslinking agent has a boiling point of less than 500 ℃ at standard pressure.

In embodiments, the crosslinking agent is independently selected from compounds of formula (II) or (III):

wherein

Y¹、Y²、Y³、Y⁴、Y⁵、Y⁶、Y⁷And Y⁸Each independently selected from hydrogen, optionally substituted branched or straight chain C₁-C₆Alkyl, optionally substituted C₁-C₆Cycloalkyl and optionally substituted C₁-C₆An aryl group; and is

L is a linker moiety.

In embodiments, the group L has the formula:

wherein

Each Y⁹Independently selected from the group consisting of a bond, -O-C (O) -, -O-, -Y¹¹-O-C(O)-、-C(O)-O-Y¹¹-、-OY¹¹-and-Y¹¹O-in which Y¹¹Is optionally substituted branched, straight or cyclic C₁-C₈An alkylene group; and is

Y¹⁰Selected from optionally substituted branched, straight or cyclic C₁-C₈Alkylene groups and siloxane groups.

In the examples, each Y⁹Is a bond.

In the examples, each Y⁹is-O-.

In the examples, each Y⁹Is a vinyl ester or vinyl ether group.

In the examples, Y¹⁰Having the formula:

wherein each Y is¹²And Y¹³Independently selected from hydrogen, halogen, optionally substituted cyclic, branched or linear C₁-C₈Alkyl or-OY¹⁴Wherein Y is¹⁴Selected from optionally substituted branched or straight chain C₁-C₈Alkyl or alkenyl, and

n "is an integer from 1 to 10.

In the examples, each Y¹²Is hydrogen and each Y¹³Is hydrogen, such that Y¹⁰Is a linear alkylene chain. For this example, Y⁹May for example be vinyl ester or vinyl ether groups.

In the examples, each Y¹²Is fluorine and each Y¹³Is fluorine, such that Y¹⁰Is a linear perfluoroalkylene chain.

n "is an integer from 0 to 10. In embodiments, the lower value of a possible range for n "is 0, 1,2, 3, 4, 5, 6, 7, 8, or 9, and/or the upper value of a possible range for n" is 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1. In embodiments, n is from 4 to 6.

In the examples, Y¹⁰Having the formula:

wherein each Y is¹⁵Independently selected from optionally substituted branched or straight chain C₁-C₆An alkyl group.

In the examples, each Y¹⁵Is methyl. In the examples, each Y⁹Is a bond.

In the examples, Y¹⁰Having the formula:

wherein Y is¹⁶、Y¹⁷、Y¹⁸And Y¹⁹Each independently selected from hydrogen and optionally substituted branched or straight chain C₁-C₈An alkyl or alkenyl group. In embodiments, the alkenyl group is vinyl.

In the examples, Y¹⁸Is hydrogen or vinyl, and Y¹⁶、Y¹⁷And Y¹⁹Each is hydrogen. In the examples, Y¹⁶、Y¹⁷、Y¹⁸And Y¹⁹Each of which is hydrogen. In another embodiment, Y¹⁸Is vinyl, and Y¹⁶、Y¹⁷And Y¹⁹Each is hydrogen.

In embodiments, the group L has one of the following structures:

in embodiments, the group L has one of the following structures:

for L, Y according to structure (e)¹⁰May be, for example, an alkylene chain or cycloalkylene group such as those shown in structures (b) and (d) above. The alkylene chain may be, for example, a linear alkylene chain.

When Y is¹⁰When cycloalkylene, this may be, for example, cyclohexylene, such as 1, 4-cyclohexylene.

For L, Y according to structure (f)¹⁰May for example be of structure (b), such as an alkylene or fluoroalkylene chain.

For L, Y according to structure (g)¹⁰May for example be a cycloalkylene group such as a cyclohexylene group according to structure (d).

For L, Y according to structure (h)¹⁰May for example be structure (b) wherein each Y is¹²And Y¹³Is F, a perfluoroalkylene chain.

For L, Y according to structure (i) or structure (j)¹⁰May for example be alkylene or cycloalkylene. Optionally, the alkylene or cycloalkylene group may be substituted with one or more vinyl or alkenyl ether groups (e.g., one or more vinyl ether groups).

When each Y is⁹When is a bond, each Y¹⁰May be, for example, any of structures (b), (c), and (d).

In the examples, Y¹⁰Is a linear alkenyl group such that the crosslinking agent is a diene, such as, for example, heptadiene, octadiene or nonadiene; in the examples, it is 1, 7-octadiene.

When each Y is⁹When is O, e.g. each Y¹⁰May be branched or straight chain C₁-C₆Alkylene, preferably straight-chain alkylene, most preferably C₄A linear alkylene group. In an embodiment, the crosslinking agent is 1, 4-butanediol divinyl ether.

It will be understood that each Y is⁹The radical may be bonded to any other Y⁹Group and Y¹⁰The groups combine to form a crosslinker.

Those skilled in the art will be aware of the above mentioned cyclic, branched or straight chain C₁-C₈Possible substituents for each of the alkylene groups. The alkylene group may be substituted at one or more positions with a suitable chemical group. Preferred are halogen substituents, most preferred are fluoro substituents. Each C₁-C₈Alkylene may be, for example, C₁-C₃、C₂-C₆Or C₆-C₈An alkylene group.

In embodiments, the crosslinker is for Y¹⁰And vinyl ester or vinyl ether groups on either side.

In the examples, the crosslinking agent is independently selected from divinyl adipate (DVA), 1, 4-butanediol divinyl ether (BDVE), 1, 4-cyclohexanedimethanol divinyl ether (CDDE), 1, 7-octadiene (17OD), 1,2, 4-Trivinylcyclohexane (TVCH), 1, 3-divinyltetramethyldisiloxane (DVTMDS), diallyl 1, 4-cyclohexanedicarboxylate (DCHD), 1, 6-Divinylperfluorohexane (DVPFH), 1H, 6H-perfluorohexanediol diacrylate (PFHDA), and glyoxalbis (diallyl acetal) (GBDA).

In an embodiment, the crosslinking agent is divinyl adipate (DVA).

In an embodiment, the crosslinker is 1, 4-butanediol divinyl ether (BDVE).

In embodiments, for compounds of formula (III), the group L may be selected, for example, from branched or linear C₁-C₈Alkylene or ether groups. L may be, for example, C₃、C₄、C₅Or C₆Alkylene groups, preferably linear alkylene groups.

The chemical structure of the crosslinker is set forth in table 1 below.

Table 1: crosslinking agent

In an embodiment, in step (ii) of the method according to the first aspect of the invention, the monomer compound and the cross-linking agent are introduced in liquid phase into the plasma deposition chamber and the volume ratio of the cross-linking agent to the monomer compound is from 1:99 to 90:10, or from 1:99 to 50:50, or from 1:99 to 30: 70.

In embodiments, the volume ratio of crosslinker to monomer compound in step (ii) is from 1:99 to 25:75, from 1:99 to 20:80, from 5:95 to 20:80, or from 5:95 to 15: 85. In an embodiment, the volume ratio of the crosslinking agent to the monomer compound is about 10: 90.

In embodiments, the volume ratio of crosslinker to monomer compound in step (ii) is 1:99, 2:98, 3:97, 4:96, 5:95, 6:96, 7:93, 8:92, 9:91 or 10:90, and/or the volume ratio of crosslinker to monomer compound is up to 90:10, 80:20, 70:30, 60:40, 50:50, 40:60, 30:70, 29:71, 28:72, 27:73, 26:74, 25:75, 24:76, 23:77, 22:78, 21:79, 20:80, 19:81, 18:82, 17:83, 16:84, 15:85, 14:86, 13:87, 12:88, 11:89 or 10: 90.

As will be known to the skilled person, the use of volumetric ratio measurements when introducing reagents into a plasma deposition chamber is common in the field of plasma deposition. Alternatively, the ratio between the monomer compound and the reagent, such as a cross-linking agent, may be expressed as a molar ratio of the reagents introduced into the chamber. This is called the molar input flow ratio.

In an embodiment, in step (ii) of the method according to the first aspect of the invention, the monomer compound and the crosslinking agent are introduced (optionally in liquid phase) into the plasma deposition chamber and the molar input flow ratio of the crosslinking agent to the monomer compound is from 1:20 to 10:1, or from 1:20 to 1: 1.

In embodiments, the molar input flow ratio of crosslinker to monomer compound is from 1:20 to 1:2, from 1:15 to 1:5, or from 1:14 to 1: 6.

In an embodiment, in step (ii), the molar input flow ratio of the crosslinking agent to the monomer compound is 1:20, 1:19, 1:18, 1:17, 1:16, 1:15, 1:14, 1:13, 1:12, 1:11, 1:10, 1:9, 1:8, 1:7, 1:6, 1:5, 1:4, 1:3, or 1:2, and/or the possible range of molar input flow ratios of the crosslinking agent to the monomer compound is up to 10:1, 9:1, 8:1, 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:19, or 1: 18.

For a particular monomer compound and crosslinker, the volume ratio of crosslinker to monomer compound can be readily converted to a molar ratio of crosslinker to monomer compound, and vice versa.

For example, when the crosslinker and monomer compound are introduced into the plasma deposition chamber in the liquid phase and the volume ratio of crosslinker to monomer compound is 10:90, if the crosslinker is DVA and the monomer compound is 1H, 2H-perfluorooctyl acrylate (PFAC6), the molar input flow ratio of DVA to PFAC6 is about 1: 6.

Similarly, when the crosslinker and monomer compound are introduced into the plasma deposition chamber in the liquid phase and the volume ratio of crosslinker to monomer compound is 5:95, if the crosslinker is DVA and the monomer compound is PFAC6, the molar input flow ratio of DVA to PFAC6 is about 1: 13.

Typically, in a plasma deposition process, an article to be treated is placed in a plasma deposition chamber, a glow discharge is ignited in the chamber, and a suitable voltage (which may be continuous wave or pulsed) is applied. The glow discharge is suitably ignited by applying a high frequency voltage (e.g. 13.56 MHz).

Each monomer compound and/or crosslinking agent may be in the form of a gas, liquid or solid (e.g., powder) at room temperature before the monomer compound and/or crosslinking agent enters the deposition chamber. However, it is preferred that the monomer compound and/or the crosslinker are both liquids at room temperature, and most preferably the monomer and crosslinker liquids are miscible.

The crosslinking agent may be miscible with the monomer and thus introduced into the plasma chamber together or separately. Or the crosslinking agent may be immiscible with the monomer and introduced separately into the plasma chamber. In this context, the term "miscible" means that the crosslinking agent is dissolved in the monomers and when they are mixed forms a solution of homogeneous composition. The term "immiscible" means that the crosslinking agent is only partially soluble or insoluble in the monomer and therefore either forms an emulsion or separates into two layers.

The monomer compound and/or cross-linking agent will suitably be in the gaseous state in the plasma. The plasma may comprise only the vapour of the monomer compound and/or the cross-linking agent. Where the compound is introduced into the chamber in liquid form, such vapor may be formed in situ. The monomer may also be combined with a carrier gas, particularly an inert gas such as helium or argon.

In a preferred embodiment, the monomer and/or cross-linker may be delivered to the chamber by an aerosol device such as a nebulizer, for example as described in WO2003/097245 and WO 2003/101621. In such an arrangement, a carrier gas that advantageously helps achieve high flow rates may not be required.

The exact flow rate of the monomeric compound and/or crosslinking agent into the chamber may depend to some extent on the nature of the particular monomeric compound and/or crosslinking agent used, the nature of the substrate, the desired coating characteristics, and the plasma chamber volume. In some embodiments of the invention, the monomer compound and/or crosslinking agent is introduced into the chamber at a gas flow rate in the range of at least 1sccm (standard cubic centimeter per minute), and preferably in the following ranges: from 1 to 2500sccm, from 1 to 2000sccm, from 1 to 1500sccm, from 1 to 1000sccm, from 1 to 750sccm, from 1 to 500sccm, from 1 to 250sccm, from 1 to 200sccm, from 1 to 100sccm, or from 5 to 60 sccm.

The monomer compound and/or cross-linker gas flow rate can be calculated from the liquid monomer flow rate, for example by using the ideal gas law, i.e. assuming that in the chamberThe monomer acts like an ideal gas, with one mole occupying 22400cm at 273K and 1 atmosphere (STP)³The volume of (a).

The step of exposing the connecting element (with the protective material) to the plasma may comprise a Pulsed (PW) deposition step. Alternatively or additionally, the step of exposing the connecting element (with the protective material) to the plasma may comprise a Continuous Wave (CW) deposition step.

The term pulse may mean that the plasma cycles between a state in which no (or substantially no) plasma is emitted (off-state) and a state in which a specific amount of plasma is emitted (on-state). Alternatively, pulsing may mean that there is continuous plasma emission, but the amount of plasma cycles between an upper limit (on state) and a lower limit (off state).

For pulsed plasmas, higher average powers can be obtained by using higher peak powers and varying the pulse states (i.e., on/off times).

Optionally, the voltages are sequentially pulsed at a ratio of on/off times in the range from 0.001 to 1 (optionally 0.002 to 0.5). For example, the open time may be 10-500. mu.s, or 35-45. mu.s, or 30-40. mu.s, such as about 36. mu.s; and the closing time may be from 0.1 to 30ms, or 0.1 to 20ms, or 5 to 15ms, for example 6 ms. The opening time may be 35. mu.s, 40. mu.s, 45. mu.s. The off time may be 0.1, 1,2, 3, 6, 8, 10, 15, 20, 25, or 30 ms.

Optionally, the voltage is applied as a pulsed field for a period of time from 30 seconds to 90 minutes. Optionally, the voltage is applied as a pulsed field for a period of time from 5 to 60 minutes.

RF power from 1 to 2000W (e.g., from 50 to 1000W, from 100 to 500W, from 125 to 250W) may be provided.

The peak power may be from 1 to 2000W, for example from 50 to 1000W, from 100 to 500W, from 125 to 250W, or about 160W.

The ratio of peak power to monomer flow for the continuous wave plasma or pulsed plasma may be from 2 to 60W/sccm, from 2 to 40W/sccm, from 2 to 25W/sccm, or from 5 to 20W/sccm.

During exposure of the substrate to the continuous wave plasma or the pulsed plasma, the peak power density of the plasma may be from 0.001 to 40W/liter, or at least 2W/liter, or about 20W/liter.

In embodiments, the thickness of the protective material is from 0.1mm to 5mm, for example from 0.5mm to 2mm, or about 1 mm.

In embodiments, the protective material is 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, or 0.9mm thick, and/or the protective material is up to 5mm, 4mm, 3mm, 2.5mm, 2mm, 1.5mm, 1.4mm, 1.3mm, 1.2mm, 1.1mm, or 1mm thick.

In embodiments, the thickness of the overcoat is from 250 to 10000nm, from 500 to 8000nm, from 1000 to 6000nm, from 1500 to 5000nm, or from 2000 to 4000 nm.

In embodiments, the thickness of the overcoat is 250nm, 500nm, 750nm, 1000nm, 1100nm, 1200nm, 1300nm, 1400nm, 1500nm, 1600nm, 1700nm, 1800nm, 1900nm, 2000nm, 2100nm, 2200nm, 2300nm, 2400nm, or 2500nm, and/or the thickness of the overcoat is up to 10000nm, 9000nm, 8000nm, 7000nm, 6000nm, 5500nm, 5000nm, 4900nm, 4800nm, 4700nm, 4600nm, 4500nm, 4400nm, 4300nm, 4200nm, 4100nm, 4000nm, 3900nm, 3800nm, 3700nm, 3600nm, 3500nm, 3400nm, 3300nm, 3200nm, 3100nm, 3000nm, 2900nm, 2800nm, 2700nm, 2600nm, 2500nm, 2400nm, 2300nm, 2200nm, 2100nm, 2000nm, or 1900 nm.

In an embodiment, the cover coating may be conformal, which may mean that it takes the 3D shape of the protective material and covers substantially the entire surface of at least the protective material. This has the advantage of ensuring that the coating has a sufficient thickness to give optimal function over the entire surface of the protective material.

In an embodiment of the method according to the first aspect of the invention, the method further comprises depositing one or more additional coatings.

In an embodiment of the method according to the first aspect of the invention, the second connection element is not coated with the protective material and/or the cover coat. In an embodiment, the second connection element is not coated.

In an alternative embodiment of the method according to the first aspect of the present invention, the method further comprises depositing a protective material as described above and optionally a cover coat as described above on the second connection element before the connection is made in step (iii).

In an embodiment of the method according to the first aspect of the present invention, the joining between the first and second connection elements in step (iii) comprises stamping the protective material and optionally the covercoat before the joining is performed.

The second connecting element can be pushed into or through the protective material and optionally through the covercoat without first stamping the protective material and optional covercoat. However, stamping the protective material before making the electrical connection may make it easier to push or pass the second connection element into or through the protective material.

In an embodiment of the method according to the first aspect of the present invention, the method further comprises cleaning, etching or activating the connection element before depositing the protective material in step (i). This preparation step can be used as an activation step to prepare the connecting element before the coating is deposited. The purpose of this step may be, for example, to make the connecting element chemically receptive to the coating (e.g., oxidized metal) and/or physically roughened to allow the coating to "key" into the substrate (e.g., to enhance mechanical interlocking).

In an embodiment, in the preparation step, a continuous power plasma may be applied to the connection element. The preparation step may be performed in the presence of an inert gas. In an embodiment, the preparing step is performed in the presence of helium and/or oxygen.

According to a second aspect of the invention there is provided a protected connection obtainable by a method according to the first aspect of the invention.

According to a third aspect of the present invention there is provided a connector comprising first and second connection elements forming a connection, the connection being protected by a dot of protective material with an overlying coating, wherein a portion of the protective material is interposed between the connection elements.

The first connection element, the second connection element, the connector, the connection, the protective material and the cover coating may be as described or defined in relation to the first aspect of the invention.

Throughout the description and claims of this specification, "comprising" and "containing" and variations of these words, for example "comprising" and "comprises", means "including but not limited to", and does not exclude other elements, features or steps. Also, unless the context requires otherwise, the singular encompasses the plural: in particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

Preferred features of each aspect of the invention may be as described in connection with any of the other aspects. Within the scope of the present application, it is expressly intended that the various aspects, embodiments, examples and alternatives set forth in the preceding paragraphs, in the claims and/or in the following description and drawings (and particularly individual features thereof) may be employed independently or in any combination. That is, all embodiments and/or features of any embodiment may be combined in any manner and/or combination unless such features are incompatible.

Drawings

One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

fig. 1 shows an electrical test setup for determining the resistance of a coating.

Fig. 2 shows a schematic example of a protective material (in the form of a gel bubble) dispensed over (a) a contact pad and (b) a spring connector.

Fig. 3 shows a plan view (a) of a board-to-board socket (or plug) surrounded by a protective material after plasma coating and a schematic view (b) of a side view of the board-to-board socket (or plug) surrounded by a protective material.

FIG. 4 shows a schematic of a method of applying a protective material and plasma coating to a ZIF connector and then inserting a cable through the protective material and plasma coating for electrical connection.

Detailed Description

Plasma deposition method

Plasma polymerization experiments were performed in a metal reaction chamber with a working volume of 22 liters. The chamber is composed of two parts: a vertically oriented shallow cuboid cavity with a single open face sealed at the outer edge to a solid metal door by a Viton O-ring. All surfaces were heated to 37 ℃. Inside the chamber there is a single perforated metal electrode (area per open face of the chamber) oriented vertically and attached to the door by a connection at the corner, powered by an RF power supply unit through a connection through the centre of the metal door. For pulsed plasma deposition, the RF power supply unit is controlled by a pulse generator.

The rear of the chamber is connected through a larger cavity (achieving a total volume 125L) to metal pump lines, pressure control valves, a compressed dry air supply, and a vacuum pump. The chamber door included several cylindrical ports for connection to a pressure gauge, a monomer delivery valve (whose inner surface was heated to 70 ℃), temperature control equipment, and a gas feed line that was in turn connected to a mass flow controller.

In each experiment, the sample was positioned vertically facing the door on a nylon spike attached to a perforated electrode.

The reactor is evacuated down to base pressure (typically<10 mTorr). The process gas is delivered into the chamber using a mass flow controller, with typical gas flow values between 2-25 sccm. Monomer is delivered into the chamber with a typical monomer gas flow value between 5-60 sccm. The chamber was heated to 37 ℃. The pressure in the reactor is maintained between 20 and 30 mTorr. The plasma was generated using an RF of 13.56 MHz. The method generally includes at least the steps of a Continuous Wave (CW) plasma and a Pulsed Wave (PW) plasma. Optionally, these steps may be performed by an initial activation step using a Continuous Wave (CW) plasma. If activated CW plasma is used, it lasts 1 minute; the CW plasma was 1 or 4 minutes and the duration of the PW plasma varied from experiment to experiment. In each casePeak power was set to 160W and the pulse condition was on time (t)_on) 37 mus and off time (t)_off) 10 ms. At the end of the deposition, the RF power was turned off, the monomer delivery valve was stopped, and the chamber pump was lowered to base pressure. The chamber was vented to atmospheric pressure and the coated sample was removed.

For each experiment, 4-6 test Printed Circuit Boards (PCBs) and accompanying Si wafers were used. The Si wafer allows measurement of the physical properties of the formed coating, such as AFM for surface morphology and XRR for coating density. The metal traces of the multiple test PCBs were copper coated with gold. The Si wafer is placed on the top front side of the PCB.

Analytical method

Several properties of exemplary coating surfaces formed according to the present invention were investigated using the following methods.

Resistance in tap water

This test method was designed to evaluate the ability of different coatings to provide electrical barriers on printed circuit boards and predict the ability of smartphones to pass IEC 6052914.2.7 (IPX7) tests. The process is designed for use with tap water. Such testing involves measuring the current-voltage (IV) characteristics of a standardized Printed Circuit Board (PCB) in water. PCBs have been designed with a 0.5mm spacing between electrodes to allow assessment of when electrochemical migration occurs across the traces in water. Quantifying the degree of electrochemical activity by measuring the current; low current indicates good coating quality. This method has proven to be extremely effective in distinguishing between different coatings. The properties of the coating can be quantified as, for example, resistance at 4V, 8V and 21V. The measured resistance on the untreated test equipment was about 100 ohms when 16V/mm was applied.

Fig. 1 shows an electrical test apparatus 100. The coated PCB 110 to be tested is placed in a beaker 112 with water 114 and connected to a power source (not shown) by connections 116, 118. The coated PCB 110 is centered both horizontally and vertically in the beaker 112 to minimize the effect of local ion concentration (the vertical position of the coated PCB 110 is important; the water 114 level should reach the blue indicator 120). When the coated PCB 110 is connected, the power supply is set to the desired voltage and the current is immediately monitored. For example, the applied voltage is 8V and the coated PCB 110 is held at the set voltage for 13 minutes during which the current is continuously monitored.

Coatings formed with different process parameters were tested. It has been found that when the resistance value of the coating is greater than 10M ohms, the coated device will pass the IPX7 test successfully. The nature of the coated device (e.g., type of smartphone) will affect the testing, e.g., due to variations in materials, access points, power consumption, etc.

Resistance in salt water

This test method is the same as the above method for "resistance in tap water", except that brine is used instead of tap water. The composition of the brine was 5% w/v NaCl, i.e. 5g NaCl per 100ml water.

Thickness of coating

The thickness of the formed coating was measured using a spectroscopic reflectometry apparatus (filmmetrics F20-UV) using optical constants verified by ellipsometry.

Spectroscopic ellipsometry

Ellipsometry is a technique for measuring the change in polarization between incident polarized light and light after interaction with a sample (i.e., reflected light, transmitted light, etc.). The polarization change is quantified by the amplitude ratio Ψ and the phase difference Δ. This variation over a range of wavelengths is measured using a broadband light source and the normalized values of Ψ and Δ are measured as a function of wavelength. The ITAC MNT ellipsometer is an AutoSE from Horiba Yvon with a wavelength range of 450 to 850 nm. A number of optical constants can be derived from the Ψ and Δ values, such as film thickness and refractive index.

The data collected from the sample measurements includes the harmonic intensities of the reflected or transmitted signals within a predetermined spectral range. These are mathematically processed to infer the exact intensity values f (i) called Is and Ic. Starting from Ic and Is, the software calculates Ψ and Δ. To extract the parameters of interest, such as thickness or optical constants, a model must be built to allow theoretical calculations for Ψ and Δ. Determining the parameter of interest by comparing theoretical and experimental data files to obtainObtaining the best fit (MSE or X)²). The best fit of the thin layer is such that X²<3, for thicker coatings this value can be as high as 15. The model used was a three-layer lorentz model comprising PTFE surface treated on a Si substrate and a mixed layer (PTFE + voids) to solve the surface roughness problem.

Spectral reflectance method

The thickness of the coating was measured using a Filmetrics F20-UV spectroreflectometry apparatus. This instrument (F20-UV) measures the properties of the coating by reflecting the light leaving the coating and analyzing the reflection spectrum generated in the wavelength range. The light reflected from the different interfaces of the coating may be in phase or out of phase, and therefore these reflections will increase or decrease depending on the wavelength of the incident light and the thickness and refractive index of the coating. The result is an intensity oscillation in the reflection spectrum that is characteristic of the coating.

To determine the thickness of the coating, filmetics software calculates a theoretical reflectance spectrum that matches the measured spectrum as closely as possible. First a preliminary guess is made as to what the reflection spectrum should look like based on the nominal coating stack (layered structure). This includes information about the thickness (with an accuracy of 0.2nm) and refractive index (refractive index values obtainable from ellipsometry) of the different layers and substrates that make up the sample. The theoretical reflectance spectrum is then adjusted by adjusting the properties of the coating until a best fit to the measured spectrum is found.

Alternative techniques for measuring thickness are stylus profilometry and coating cross-section by SEM measurement.

Monomer compound

The monomer compound used in these examples was PFAC6, 1H,2H, 2H-perfluorooctyl acrylate of the formula (CAS # 17527-29-6):

crosslinking agent

The crosslinker used in these examples is divinyl adipate (DVA) (CAS #4074-90-2) of the formula:

EXAMPLE A formation of plasma coating

A 2500nm thick coating was deposited on a Printed Circuit Board (PCB) and accompanying Si wafers using perfluorinated acrylate monomer PFAC6 and crosslinker DVA premixed in a 9:1 volume ratio and introduced into the plasma deposition chamber in the liquid phase in a gas phase plasma deposition process as described above.

The barrier properties of the coatings on the PCBs were tested by the above tests and the results are shown in table 2.

Table 2: properties of plasma deposited coatings

EXAMPLE 1 use of self-healing gel to protect spring connectors

The self-healing gel is dispensed on areas of the Printed Circuit Board (PCB) where electrical connections are required, such as spring connectors or contact pads. Dispensing of the gel may be manual or automatic. The gel may be dispensed as one or more discrete units. Once dispensed, the unit size may be about 2.5mm wide and 1mm high.

The self-healing gel is silicone rubber. The base material (prior to curing) is a silicone rubber blend. The catalyst contains a platinum additive.

The self-healing gel had the following properties:

base material viscosity before curing: 55,000cPs at 25 ℃

Catalyst viscosity before curing: 1,000cPs at 20 ℃

Mixing viscosity before curing: 42,000cPs at 23 ℃

Mixing ratio: 10:1 base material by volume: catalyst and process for preparing same

The curing mechanism is as follows: UV curing with broadband UV source

Penetration hardness after curing (ISO 2137, 9.38g hollow cone): 70mm/10

Dielectric strength: 23kV

The gel was cured under a 365nm UV LED (cure time 19s, distance 10mm) and then treated with a fluoropolymer plasma deposited coating as described in example a.

After fluoropolymer processing, the gel may be impacted at a defined speed and diameter using a spring-loaded punch prior to reassembly to ensure contact can be pushed through the gel.

Fig. 2(a) shows a schematic example of a PCB202 with contact pads 220 for connecting components 204 with spring connectors 230. In this example, the gel 210 is dispensed over the contact pads 220 such that the contact pads 220 are completely encapsulated within the gel 210. Subsequently, a fluoropolymer coating 212 is deposited on the PCB202 and the gel 210. When the component 204 is brought towards the PCB202 for connection, the contact portion 232 of the spring connector 230 contacts the fluoropolymer coating 212. The gel 210 under the fluoropolymer coating 212 acts as a cushion, thereby embrittling the fluoropolymer layer 212. Thus, the contact portion 232 of the spring connector 230 is able to break through the brittle fluoropolymer layer 212 and engage the contact pad 220 within the gel 210.

Fig. 2(b) shows a schematic diagram of a PCB with a spring connector 230 for connecting a component 204 with contact pads 220. In this example, the gel 210 is dispensed over the spring connector 230 such that the contact portion 232 of the spring connector 230 is completely enclosed within the gel 210. Subsequently, a fluoropolymer coating 212 is deposited on the PCB202, a portion of the spring connector 230, and the gel 210. The gel 210 acts as a mask, preventing the contact portions 232 of the spring connector 230 from being coated with fluoropolymer.

When the component 204 is brought towards the PCB202 for connection, the gel 210 under the fluoropolymer coating 212 acts as a cushion and allows the contact pad 220 to be pushed through the brittle fluoropolymer layer 212. The contact pins 232 and pads 220 are protected from corrosion by the self-healing gel 210 without a demasking step.

Alternatively, a separate tool may be used to break a hole in the fluoropolymer layer 212 in a preparation step before bringing the component 204 to the PCB202 for connection.

Example 2-use of self-healing gel to protect board-to-board connectors

The self-healing gel is dispensed in the area of the Printed Circuit Board (PCB) where electrical connection is desired, such as around the perimeter of a receptacle or header of a board-to-board connector pair. The dispensing of the gel may be manual or automatic and the thickness of the gel should be greater than the height of the part. The exact amount of gel depends on the size and layout of the board-to-board connectors, but there must be enough gel to cover and protect the external terminals on the unprocessed connectors when the connectors are mated. The gel may be applied such that there is a gap between the board-to-board connector and the gel. The gel may be applied only to those sides of the board-to-board connector having exposed terminals.

The self-healing gel is silicone rubber. The base material (prior to curing) is a silicone rubber blend. The catalyst contains a platinum additive.

The self-healing gel had the following properties:

base material viscosity before curing: 55,000cPs at 25 ℃

Catalyst viscosity before curing: 1,000cPs at 20 ℃

Mixing viscosity before curing: 42,000cPs at 23 ℃

Mixing ratio: 10:1 base material by volume: catalyst and process for preparing same

The curing mechanism is as follows: UV curing with broadband UV source

Penetration hardness after curing (ISO 2137, 9.38g hollow cone): 70mm/10

Dielectric strength: 23kV

After dispensing, the gel was cured under a 365nm UV LED (cure time 19s, distance 10mm) and then treated with a fluoropolymer plasma deposited coating as described in example a.

The other connector does not need to be handled separately, so that the pair of connections can be mated.

Fig. 3 shows a plan view (a) of a board-to-board socket 320 surrounded by a gel 310 and a schematic view (b) of a side view of the board-to-board socket 320 surrounded by the gel 310 after plasma coating to form a fluoropolymer plasma deposited coating 312. The (untreated) board-to-board plug 322 is brought into contact with the board-to-board socket 320 and pushed through the fluoropolymer plasma deposited coating 312 to form a connection. When the receptacle 320 and plug 322 are mated, the terminals 324, 326 on either side of the (untreated) board-to-board plug 322 are protected by the gel 310. Alternatively, the receptacle 320 may be a plug and the (unprocessed) plug 322 may be a receptacle.

EXAMPLE 3-use of self-healing gel to protect ZIF connectors

The self-healing gel is dispensed on the Printed Circuit Board (PCB) area where electrical connection is required, such as on a ZIF connector. The dispensing of the gel may be manual or automatic, and the amount of gel depends on the size and layout of the ZIF connector. There must be enough gel to ensure that the terminals on the inserted ZIF jumper cable are fully submerged and protected.

The self-healing gel is silicone rubber. The base material (prior to curing) is a silicone rubber blend. The catalyst contains a platinum additive.

The self-healing gel had the following properties:

base material viscosity before curing: 55,000cPs at 25 ℃

Catalyst viscosity before curing: 1,000cPs at 20 ℃

Mixing viscosity before curing: 42,000cPs at 23 ℃

Mixing ratio: 10:1 base material by volume: catalyst and process for preparing same

The curing mechanism is as follows: UV curing with broadband UV source

Penetration hardness after curing (ISO 2137, 9.38g hollow cone): 70mm/10

Dielectric strength: 23kV

After dispensing, the gel was cured under a 365nm UV LED (cure time 19s, distance 10mm) and then treated with a fluoropolymer plasma deposited coating as described in example a.

The ZIF cable need not be handled separately and can be inserted through the gel to the ZIF connector and the closed lever.

FIG. 4 shows a schematic of a method of applying a gel and plasma coating to a ZIF connector and then inserting a cable through the gel and plasma coating for electrical connection. In more detail, referring to fig. 4(a), the gel 410 is dispensed on a portion of the ZIF connector 420 on the PCB402, with the lever 422 of the ZIF connector 420 in a downward (closed) position. As shown in fig. 4(b), a fluoropolymer coating 412 is then deposited on the PCB402, the gel 410, and the portions of the ZIF connector 420 on which the gel 410 is not dispensed. As shown in fig. 4(c), the lever 422 is then moved to the up (open) position and the ZIF cable 430 is inserted through the frangible fluoropolymer coating 412 and through the gel 410 into the ZIF connector 420. Referring to fig. 4(d), the lever 422 returns to the downward (closed) position to lock the ZIF cable 430 in the ZIF connector 420.

The gel 410 may be dispensed over a portion of the ZIF connector 420 when the lever 422 of the ZIF connector is in the up (open) position.