阅读说明：本技术 涂层 (Coating layer ) 是由 斯蒂芬·理查德·科尔森 戴尔文·埃文斯 安杰里奇·西欧库 克莱夫·特尔福德 于 2016-06-08 设计创作，主要内容包括：本发明公开了一种电子或电气装置或其元件,其包括在电子或电气装置或其元件表面上的交联聚合物涂层；其中,交联聚合物涂层通过使电子或电气装置或其元件在包含单体化合物和交联剂的等离子体中暴露足够时间,以允许在其表面上形成交联聚合物涂层而获得；其中,单体化合物具有下式：<Image he="276" wi="311" file="DDA0002252997490000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>其中,R<Sub>1</Sub>、R<Sub>2</Sub>和R<Sub>4</Sub>各自独立地选自氢、任意经取代的支链或直链C<Sub>1</Sub>-C<Sub>6</Sub>烷基或卤代烷基、或可选被卤素取代的芳基,并且R<Sub>3</Sub>选自：<Image he="242" wi="700" file="DDA0002252997490000012.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>其中,X各自独立地选自氢、卤素、任意经取代的支链或直链C<Sub>1</Sub>-C<Sub>6</Sub>烷基、卤代烷基或可选被卤素取代的芳基；且n<Sub>1</Sub>为1至27的整数；并且交联剂包含借助于一个或多个连接部分连接的两个或多个不饱和键,并且在标准压力下具有小于500℃的沸点。(An electronic or electrical device or component thereof comprising a crosslinked polymer coating on a surface of the electronic or electrical device or component thereof; wherein the crosslinked polymeric coating is obtained by exposing the electronic or electrical device or component thereof to a plasma comprising a monomeric compound and a crosslinking agent for a time sufficient to allow the formation of a crosslinked polymeric coating on the surface thereof; wherein the monomer compound has the formula: wherein R is 1 、R 2 And R 4 Each independently selected from hydrogen, optionally substituted branched or straight chain C 1 ‑C 6 Alkyl or haloalkyl, or aryl optionally substituted with halogen, and R 3 Selected from: wherein each X is independently selected from hydrogen, halogen, optionally substituted branched or straight chain C 1 ‑C 6 An alkyl, haloalkyl or aryl optionally substituted with halo; and n is 1 Is an integer from 1 to 27; and the crosslinker comprises two or more unsaturated bonds connected by means of one or more linking moieties and has a boiling point of less than 500 ℃ at standard pressure.)

1. An electronic or electrical device or an electronic or electrical component thereof comprising a protective crosslinked polymer coating on a surface of the device or component;

wherein the protective crosslinked polymeric coating is obtainable by exposing the device or component to a plasma comprising a monomeric compound and a crosslinking agent for a period of time sufficient to allow the protective crosslinked polymeric coating to form on the surface thereof;

wherein the monomer compound has the formula:

wherein R is₁、R₂And R₄Each independently selected from hydrogen, optionally substituted branched or straight chain C₁-C₆Alkyl, or haloalkyl, or aryl optionally substituted with halogen, and R₃Selected from:

wherein each X is independently selected from hydrogen, halogen, optionally substituted branched or straight chain C₁-C₆An alkyl, haloalkyl, or aryl optionally substituted with halo; and n is₁Is an integer from 1 to 27; and wherein the cross-linking agent comprises two or more linking moieties linked by one or more linking moietiesA plurality of unsaturated bonds and has a boiling point of less than 500 ℃ at standard pressure.

2. A device or element according to claim 1, wherein the protective cross-linked polymer coating is a physical barrier to mass and electron transport, and/or wherein the protective cross-linked polymer coating forms a liquid-repellent surface defined by a static Water Contact Angle (WCA) of at least 90 °.

3. A method for processing an electronic or electrical device or an electronic or electrical element thereof, comprising: exposing the device or component to a plasma comprising a monomer compound and a crosslinking agent for a period of time sufficient to allow a protective crosslinked polymeric coating to form on the surface of the device or component;

wherein the monomer compound has the formula:

wherein R is₁、R₂And R₄Each independently selected from hydrogen, optionally substituted branched or straight chain C₁-C₆Alkyl, or haloalkyl, or aryl optionally substituted with halogen, and R₃Selected from:

wherein each X is independently selected from hydrogen, optionally substituted branched or straight chain C₁-C₆An alkyl, haloalkyl, or aryl optionally substituted with halo; and n is₁Is an integer from 1 to 27; and wherein the cross-linking agent comprises two or more unsaturated bonds connected by one or more linking moieties and has a boiling point of less than 500 ℃ at standard pressure, the cross-linking agent optionally being present in an amount of 10-60 (v/v)% of the total volume of the monomer compound and the cross-linking agent.

4. A method according to claim 3, wherein the electronic or electrical device or component thereof is placed in a plasma deposition chamber, a glow discharge is ignited in the chamber, and a voltage is applied in the form of a pulsed field, and optionally one or more of the following applies:

the power of the applied voltage is 40 to 500W;

the voltage is a train of pulses, with on-times: the ratio of off-times is in the range of 1:500 to 1: 1500;

the voltage is a sequence of pulses, wherein the power is on for 20 to 50 μ s and off for 1000 to 30000 μ s;

the voltage is applied as a pulsed field for a period of 30 seconds to 90 minutes, optionally 5 to 60 minutes;

feeding the monomer compound and/or the crosslinking agent in gaseous form into the plasma at a rate of 80 to 300 mg/min while the pulsed voltage is applied;

the average power of the plasma is 0.001-500 w/m³Is generated.

5. A device, element or method according to any preceding claim wherein the cross-linking agent has one of the following structures:

(i)

wherein, Y₁、Y₂、Y₃、Y₄、Y₅、Y6、Y₇And Y₈Each independently selected from hydrogen, optionally substituted cyclic, branched or straight chain C₁-C₆An alkyl or aryl group; and L is a linking moiety.

6. A device, element or method according to claim 5 wherein for compound (i), L has the formula:

Y₉each independently 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 cyclic, branched or straight chain C₁-C₈An alkylene group; and is

Y₁₀Selected from optionally substituted cyclic, branched or linear C₁-C₈Alkylene and siloxane groups; and wherein optionally

Y₁₀Having the formula:

wherein each Y is₁₂And Y₁₃Each independently selected from H, halogen, optionally substituted cyclic, branched or straight chain alkyl, or-OY₁₄Wherein Y is₁₄Selected from optionally substituted branched or straight chain C₁-C₈Alkyl or alkenyl, and n is an integer from 1 to 10; or

Y₁₀Having the formula:

wherein each Y is₁₅Each independently selected from optionally substituted branched or straight chain C₁-C₆Alkyl, optionally

Wherein Y is₁₅Each is methyl, and Y₉Each is a bond; or

Y₁₀Having the formula:

wherein, Y₁₆To Y₁₉Each independently selected from H and optionally substituted branched or straight C₁-C₈An alkyl or alkenyl group; optionally, optionally

Wherein Y is₁₈Is H or vinylidene, and Y₁₆、Y₁₇And Y₁₉Each is H.

7. A device, element or method according to any one of the preceding claims wherein the cross-linking agent is 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).

8. A device, element or method according to any preceding claim wherein n1 is in the range 1 to 12, and/or

Wherein the monomer is a compound of formula I (a):

I(a)

wherein R is₁、R₂、R₄And R₅To R₁₀Each independently selected from hydrogen, or optionally substituted C₁-C₆Branched or straight chain alkyl; each X is independently selected from hydrogen or halogen; a is 0 or 1; b is 3 to 7; c is 0 or 1;

or

The monomer is a compound of formula I (b):

I(b)

wherein，R₁、R₂、R₄And R₅To R₁₀Each independently selected from hydrogen, or optionally substituted C₁-C₆Branched or straight chain alkyl; each X is independently selected from hydrogen or halogen; a is 0 or 1; b is 3 to 7; c is 0 or 1.

9. A device, element or method according to claim 8 wherein R₁、R₂、R₄And R₅To R₁₀Each independently selected from hydrogen or methyl.

10. A device, element or method according to claim 8 or 9 wherein R₁And R₂Are each hydrogen, R₅To R₈Each is hydrogen.

11. A device, element or method according to any one of the preceding claims wherein each X is H.

12. An electronic or electrical device or component thereof according to any one of claims 1 to 10, wherein X is F.

13. A device, element or method according to any one of claims 1 to 7 wherein the compound of formula I (a) has the formula:

wherein n is 2 to 10, optionally

Wherein the compound of formula I (a) 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 (PFAC10), or the compound of formula I (a) has the formula:

wherein n is 2 to 10; optionally, optionally

Wherein the compound of formula I (a) is selected from the group consisting of 1H,1H,2H, 2H-perfluorohexyl methacrylate (PFMAC4), 1H,2H, 2H-perfluorooctyl methacrylate (PFMAC6) and 1H,1H,2H, 2H-perfluorodecyl methacrylate (PFMAC 8).

14. A device, element or method according to any one of claims 1 to 7 wherein the compound of formula I (a) has the formula:

wherein n is 2 to 10, and/or the compound of formula I (a) is selected from ethylhexyl acrylate, hexyl acrylate, decyl acrylate, lauryl (dodecyl) acrylate and isodecyl acrylate, or

Wherein the monomer is a compound of formula I (b) and has the formula:

wherein n is 4 to 12, optionally wherein R₁、R₂And R₃Each is H.

15. A device, element or method according to any preceding claim wherein the device or element thereof is selected from a mobile telephone; a smart phone; a pager; a radio; sound and audio systems, such as speakers, microphones, ringer and/or buzzer; a hearing aid; personal audio devices such as personal CDs, tape cassettes, or MP3 players; a television set; a DVD player including a portable DVD player; a video recorder; digital and other set-top boxes; computers and related components, such as laptops, notebooks, tablets, tablet or palmtop, Personal Digital Assistants (PDAs), keyboards or instruments; a game console; a data storage device; an outdoor lighting system; radio antennas and other forms of communication equipment, and printed circuit boards.

Technical Field

The present invention relates to protective coatings, and more particularly, to protective coatings for electronic or electrical devices and components thereof, and methods of forming such coatings. The coating may be protected by having hydrophobicity and blocking water-based liquids from entering the electronic device, or may be protected by forming a barrier coating, thus providing electrical resistance between the electronic components of the phone and the water-based liquid.

Background

Monounsaturated monomers are used to make barrier coatings using a plasma polymerization process (see co-pending application).

Perfluoroalkyl chain monomers are also used to create hydrophobic surfaces by a pulsed plasma deposition process (see WO9858117a 1).

The power of the plasma-initiated polymerization affects the properties of the polymer produced. The higher average energy input of the continuous wave plasma causes more fragmentation of the monomer, and thus the polymer loses the structural properties of the monomer. In the case of 1H,1H,2H, 2H-perfluorodecyl acrylate (PFAC8), perfluoroalkyl chains are less retained and the contact angle of the surface coating is compromised. Higher plasma energies also cause more crosslinking. For pulsed plasmas with lower average energy input, there is better monomer structure retention and less crosslinking. The higher retention of perfluorinated chains at low energy, pulsed plasma conditions cause the best contact angle level for the surface coating.

When the perfluoroalkyl chain has eight or more fluorinated carbons (long chain), the polymer made from the monomer has a crystalline structure. When the perfluoroalkyl chain has less than eight fluorinated carbons, the resulting polymer is amorphous and thus may be unstable in the presence of water (see Molecular Aggregation Structure and Surface Properties of Poly (fluoroalkyl acrylate) Films, macromolecules (Molecular Aggregation structures and Surface Properties of Poly (fluoro acrylate) Thin Films, marcoolecules), 2005, volume 38, page 5699-.

When long chain perfluoroalkyl polymers are prepared by high average power (continuous wave or CW) or low average power (pulsed wave or PW) plasma, the polymers are not tacky to the touch and stable in the presence of water due to the crystal structure of the long chain. However, the feel and water stability of shorter chain polymer coatings is affected by the level of plasma power used. For example, when PFAC6(1H, 2H-perfluorooctyl acrylate) is polymerized under low power plasma conditions, the resulting polymer coating may have several disadvantages. For example, the coating may cause the water droplets to spread very little (slip off), be marked by the presence of water droplets on the surface, have a sticky feel, or be easily smeared (e.g., on silicon wafer and ABS plastic substrates).

By increasing the power of the plasma used for the polymerization, the degree of crosslinking of the polymer becomes higher and becomes more resistant to smearing. However, increasing power has the concomitant effect of decreasing the water contact angle by more monomer fragmentation (as described above). Figure 1 shows the effect of increasing the power of a CW plasma with monomer flow in a 125 liter chamber: at a ratio of 4W/μ l/min, the water contact angle was about 85 to 95 degrees, and the coating was tack-free. However, as the ratio decreases, the contact angle increases and the incidence of sticky/smudge coatings also increases. Figure 2 shows the same effect under pulsed plasma conditions. These results indicate that the process window for producing a tack-free and contamination-free coating has a limited plasma treatment range, and that the final coating has a compromised water contact angle.

The object of the present application is therefore to solve one or more of the above mentioned problems in prior art coatings.

Disclosure of Invention

One aspect of the present invention provides an electronic or electrical device or component thereof comprising a protective crosslinked polymer coating on a surface of the electronic or electrical device or component thereof;

wherein the protective crosslinked polymeric coating is obtained by exposing the electronic or electrical device or component thereof to a plasma comprising a monomeric compound and a crosslinking agent for a time sufficient to allow the formation of the protective crosslinked polymeric coating on the surface thereof,

wherein the monomer compound has the formula:

wherein R is₁、R₂And R₄Each independently selected from hydrogen, optionally substituted branched or straight chain C₁-C₆Alkyl or haloalkyl or aryl optionally substituted by halogen, and R₃Selected from:

wherein each X is independently selected from hydrogen, halogen, optionally substituted branched or straight chain C₁-C₆An alkyl, haloalkyl or aryl optionally substituted with halo; and n is₁Is an integer from 1 to 27; and the crosslinking agent comprises two or more unsaturated bonds connected by means of one or more linker moieties and has a boiling point of less than 500 ℃ at standard pressure。

High levels of polymer crosslinking, previously achievable only with high average power continuous wave plasmas, can be achieved by adding crosslinking molecules to the monomers to produce crosslinked copolymers. This has the advantage of increasing the plasma treatment range, so that stable coatings can now be produced under low average energy pulsed plasma conditions.

The high retention of hydrophobic monomer structure by the low energy pulsed plasma makes the coatings composed of the copolymer both good hydrophobic coatings (as evidenced by water contact angles) and coatings that are non-tacky to the touch or not easily soiled. These characteristics therefore make it suitable for coatings for electronic devices to prevent the ingress of aqueous based liquids causing accidental damage. The thickness of such a coating is generally between 1 and 100nm, preferably between 1 and 50 nm.

The coating may be described as a liquid repellent layer, typically a water repellent layer. The coating may repel water, liquid (e.g., rain) or oil.

Alternatively, the coating may be a physical barrier layer in addition to providing a liquid repellent layer.

The coating may be a physical barrier, e.g., the coating provides a physical barrier to mass and electron transport.

The physical barrier layer limits diffusion of water, oxygen, and ions. When the coating is a physical barrier, the thickness of the coating is typically in excess of 50 nm.

The coating is a protective layer, e.g., the coating prevents damage from contact with water or other liquids. The coating may provide a protective function by forming a liquid repellent layer and/or a physical barrier layer.

The coating is preferably substantially free of pinholes, so that it can provide a physical barrier. Preferably Δ Z/d <0.15, where Δ Z is the average height change in AFM line scan in nm (as shown in FIG. 3) and d is the coating thickness in nm.

The value of Δ Z/d tells us how far the defects/voids on the surface of the coating extend into the coating, i.e. the percentage value of the depth of the defect relative to the total coating thickness. For example, Δ Z/d of 0.15 means that the voids on the surface extend down to 15% of the coating thickness. Coatings with Δ Z/d <0.15 are defined herein as being substantially free of pinholes. If the gap is larger than this value, it is unlikely that the desired function is obtained.

The coating is preferably a conformal coating, which means that it takes on the 3D shape of the electronic or electrical device or component thereof and covers substantially the entire surface of the device. This is advantageous to ensure that the coating has a sufficient thickness over the entire surface of the device or component for optimal function. The meaning of the term "substantially covers the entire surface" depends to some extent on the type of surface to be covered. For example, for some components, it may be desirable to completely cover the surface so that the component remains functional after immersion in water. However, for other elements or housings, small gaps in coverage may be tolerated.

The thickness of the coating is 50 to 10000nm, optionally 50 to 8000nm, 100 to 5000nm, preferably 250nm to 5000nm, most preferably 250nm to 2000 nm.

The coating may be electrically insulating and sufficiently flexible so that the electrical connector may be connected to and form an electrical connection between the electrical connector and the electronic or electrical device or component thereof without first removing the coating. In this case, the force exerted by the electrical connector on the coating is sufficient to alter the structure of the coating locally to the electrical connector or even break the coating, thereby allowing an electrical connection to be made. For coatings with a thickness below 5000nm and high performance coatings below 2000nm, electrical connectors can generally be connected to electronic or electrical devices or components in this manner.

When power is applied to an electronic or electrical device or component, the electronic or electrical device or component thereof can typically withstand immersion in up to 1 meter of water for more than 30 minutes without failure or corrosion. The effectiveness of the coating can be determined by measuring the resistance at a fixed voltage when immersed in water for a set period of time; for example, a voltage of 8V is applied for 13 minutes to the coating of a device immersed in water. The resistance value in this test was 1X 10⁷Ohmic or higher coatings are effective barrier coatings and the coated electronic or electrical device or component thereof will successfully pass the IPX7 test. IPX7 test provided for water as an entry protection markerThe degree of protection is classified and graded. In the IPX7 test on the phone, the device was submerged in water (up to 1 meter of water) for a period of 30 minutes under specified pressure and time conditions. The device must be powered on during the test and still function after 24 hours.

In one embodiment, the coating is electrically insulating and has a thickness of less than 1 micron, and applying a force of 5 to 20g to the coating using a circular probe having a diameter of 1mm allows for an electrical connection to be made with an electronic or electrical device or component thereof in the local area where the force has been applied.

In another embodiment, the coating is electrically insulating and has a thickness of 1 to 2.5 microns, and applying a force of 20 to 100g to the coating using a circular probe having a diameter of 1mm allows an electrical connection to be made in the local area where the coating has applied the force.

The density of the coating may be higher than the density of the corresponding monomer forming the coating. For example, the density increase can be at least 0.1g/cm³. The increase in density can be explained by a highly crosslinked coating. The high density of the coating improves the barrier properties of the coating.

The coating may form a surface defined by a static Water Contact Angle (WCA) of at least 70 °. Coatings with a WCA of at least 90 ° are liquid repellent layers, typically water repellent layers. For fluorinated polymers, the static water contact angle of the coating may be at least 100 °. The contact angle of a liquid on a solid substrate indicates the surface energy, which in turn indicates the liquid repellency of the substrate. The contact angle was measured by using a 3 μ l drop of deionized water on a VCA Optima contact angle analyzer at room temperature.

Crosslinking agent

The essential requirement of the crosslinking agent is the presence of two or more unsaturated bonds, for example-C ═ C-or alkynyl. The unsaturated bonds are linked by one or more linking moieties. The linking moiety is not particularly limited as long as two or more unsaturated bonds are linked together. The boiling point of the crosslinking agent at standard pressure must be less than 500 ℃, preferably from-10 to 300 ℃, optionally from 180 to 270 ℃, most preferably from 205 to 260 ℃. Preferably, but not necessarily, the crosslinking agent is not unduly hazardous for use in plasma processing, that is, it can be used in manufacturing environments where low levels of steam do not present any significant health and safety concerns, such as severe oxidation, explosion, toxicity, or having an unpleasant odor (e.g., a malodorous agent). The crosslinking agent preferably has one of the following structures:

wherein, Y₁、Y₂、Y₃、Y₄、Y₅、Y₆、Y₇And Y₈Each independently selected from hydrogen, optionally substituted cyclic, branched or straight chain C₁-C₆An alkyl or aryl group; and L is a linking moiety.

Most preferably, L has the formula:

wherein, Y₉Each independently 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 cyclic, branched or straight chain C₁-C₈An alkylene group; and

Y₁₀selected from optionally substituted cyclic, branched or straight chain C₁-C₈Alkylene groups and siloxane groups.

In a most preferred embodiment, Y₁₀Having the formula:

wherein, Y₁₂And Y₁₃Each independently selected from H, halogen, optionally substituted cyclic, branched or straight chain 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.

Alternatively, Y₁₂Independently of each other is H and Y₁₃Independently of one another, H, e.g. Y₁₀Is a linear alkylene chain. For this example, Y₉Vinyl esters or vinyl ether groups are preferred.

Alternatively, Y₁₂Each being fluorine and Y₁₃Each being fluorine, e.g. Y₁₀Is a linear perfluoroalkylene chain.

Typically, n is from 4 to 6.

In another embodiment, Y₁₀Having the formula:

wherein, Y₁₅Each independently selected from optionally substituted branched or straight chain C₁-C₆An alkyl group.

In one embodiment, Y₁₅Each is methyl, and Y₉Each is a bond.

In another embodiment, Y₁₀Having the formula:

wherein, Y₁₆To Y₁₉Each independently selected from H and optionally substituted branched or straight C₁-C₈An alkyl or alkenyl group. Preferably, the alkenyl group is vinyl. Alternatively, Y₁₈Is H or vinyl, and Y₁₆、Y₁₇And Y₁₉Each is H. In one embodiment, Y₁₆To Y₁₉Each is H. In another embodiment, Y₁₈Is vinyl, and Y₁₆、Y₁₇And Y₁₉Each is H.

In a preferred embodiment of compound (i), L has one of the following structures:

in another embodiment of compound (i), L has one of the following structures:

for L, Y according to structure (vii)₁₀Preferred are alkylene chains or cycloalkylene groups such as those shown in structures iv) and vi) above. The alkylene chain may be a linear alkylene chain. When Y is₁₀When it is a cycloalkylene group, a cyclohexylene group is preferable, and a1, 4-cyclohexylene group is most preferable.

For L, Y according to structure (viii)₁₀Preferred is structure (iv), for example, an alkylene or fluoroalkylene chain.

For L, Y according to Structure (ix)₁₀Cycloalkylene radicals, such as cyclohexylene radicals according to structure (vi), are preferred.

For L, Y according to structure (x)₁₀Preferred is structure (iv) wherein Y₁₂And Y₁₃Each F, for example, a perfluoroalkylene chain.

For L, Y according to structure (xi) or structure (xii)₁₀Preferably alkylene or cycloalkylene. Alternatively, the alkylene or cycloalkylene group may be substituted with one or more vinyl or alkenyl ether groups, preferably one or more vinyl ether groups.

When Y is₉When each is a bond, Y₁₀Each may be any of structures (iv), (v), and (vi). Preferably, Y₁₀Is a straight chain alkylene such that the crosslinking agent is a diene, for example heptadiene, octadiene or nonadiene, most preferably 1, 7-octadiene.

When Y is₉Each is O, Y₁₀Each preferably branched or straight C₁-C₆Alkylene, preferably straight-chain alkylene, most preferably C₄The linear alkylene group, for example, the crosslinking agent is 1, 4-butanediol divinyl ether.

It should be understood that Y₉Each radical may be bonded to any other Y₉Group and Y₁₀The groups combine to form a crosslinker.

Those skilled in the art will appreciate that the above-mentioned cyclic, branched or straight chain C₁-C₈Alkylene groups are each a possible substituent. The alkylene group may be substituted at one or more positions with a suitable chemical group. Halogen substituents are preferred, with fluoro substituents being most preferred. C₁-C₈Alkylene groups may each be C₁-C₃、C₂-C₆Or C₆-C₈An alkylene group.

A particularly preferred embodiment of the crosslinking agent has Y₁₀And has a vinyl ester or vinyl ether group on either side.

Particularly preferred crosslinkers are divinyl adipate (a divinyl ester).

Another preferred crosslinking agent is 1, 4-butanediol divinyl ether (a divinyl ether).

For the most preferred embodiment, the crosslinking agent is selected from the group consisting of 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, 6H-perfluorohexanediol diacrylate (PFHDA), and glyoxalbis (diallyl acetal) (GBDA).

For the alkyne crosslinker according to compound (ii), L is preferably selected from branched or linear C₁-C₈Alkylene groups or ether groups. L may be C₃、C₄、C₅Or C₆Alkylene groups, preferably linear alkylene groups. Particularly preferred chemical structures of the crosslinking agents are listed in table 1 below:

TABLE 1

Monomer compound

The monomeric compound has the formula:

wherein R is₁、R₂And R₄Each independently selected from hydrogen, optionally substituted branched or straight chain C₁-C₆Alkyl or haloalkyl or aryl optionally substituted by halogen, and R₃Selected from:

wherein each X is independently selected from hydrogen, halogen, optionally substituted branched or straight chain C₁-C₆An alkyl, haloalkyl or aryl optionally substituted with halo; and n is₁Is an integer from 1 to 27. Preferably, n₁Is 1 to 12. Alternatively, n₁From 4 to 12, optionally from 6 to 8.

In a preferred embodiment, R₃Selected from:

wherein m is₁Is an integer from 0 to 13, each X is independently selected from hydrogen, halogen, optionally substituted branched or straight chain C₁-C₆An alkyl, haloalkyl or aryl optionally substituted with halo; m is₂Is an integer from 2 to 14;

in a particularly preferred embodiment, the monomer is a compound of formula i (a):

I(a)

wherein R is₁、R₂、R₄And R₅To R₁₀Each independently selected from hydrogen or optionally substituted C₁-C₆Branched or straight chain alkyl; each X is independently selected from hydrogen or halogen; a is 0 to 10; b is 2 to 14; c is 0 or 1; or

The monomer is a compound of formula I (b):

I(b)

wherein R is₁、R₂、R₄And R₅To R₁₀Each independently selected from hydrogen or optionally substituted C₁-C₆Branched or straight chain alkyl; each X is independently selected from hydrogen or halogen; a is 0 to 10; b is 2 to 14; c is 0 or 1.

Halogen may be chlorine or bromine, but in order to comply with RoHS regulations (hazardous substances restriction directive), fluorine is preferred.

a is 0 to 10, preferably 0 to 6, optionally 2 to 4, most preferably 0 or 1. b is 2 to 14, optionally 2 to 10, preferably 3 to 7.

R₁、R₂、R₄And R₅To R₁₀Each independently selected from hydrogen or C₁-C₆Branched or straight chain alkyl. The alkyl group may be substituted or unsubstituted, saturated or unsaturated. When the alkyl group is substituted, the position or type of the substituent is not particularly limited as long as the resulting polymer provides a suitable liquid repellent and/or barrier layer. Suitable substituents will be known to those skilled in the art. If the alkyl group is substituted, preferably the substituent is halogen, i.e. R₁、R₂、R₄And R₅To R₁₀Any of which may be a haloalkyl group, preferably a fluoroalkyl group. Other possible substituents may be hydroxyl or amine groups. If the alkyl group is unsaturated, it may contain one or more alkenyl or alkynyl groups.

R₁、R₂、R₄And R₅To R₁₀Each 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 a preferred embodiment, R₁、R₂、R₄And R₅To R₁₀Each independently selected from hydrogen or methyl.

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

In a preferred embodiment, each X is H. In an alternative preferred embodiment, each X is F.

Alternatively, R₁And R₂Are all hydrogen.

Alternatively, R₄Is hydrogen or methyl. Preferably, R₁And R₂Are each hydrogen, R₄Is hydrogen or methyl.

Alternatively, R₉Is hydrogen and R₁₀C being branched or straight chain₁-C₆An alkyl group. In a preferred embodiment, R₁₀Is methyl.

In one embodiment, R₅To R₈Each is hydrogen.

In one embodiment, R₁、R₂、R₄And R₅To R₁₀Each is hydrogen, each X is H, a ═ 0 and ═ 0.

In a particularly preferred embodiment, the monomeric compound has the formula:

wherein n is 2 to 10.

In another preferred embodiment, the monomeric compound has the formula:

wherein n is 2 to 10.

The monomer compound is selected from the group consisting of 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).

The monomer compound is selected from the group consisting of 1H,1H,2H, 2H-perfluorohexyl methacrylate (PFMAC4), 1H,2H, 2H-perfluorooctyl methacrylate (PFMAC6) and 1H,1H,2H, 2H-perfluorodecyl methacrylate (PFMAC 8).

The monomeric compound of formula i (a) may have the formula:

wherein a and c are each independently 0 or 1, b is 3-7 and n is 4 to 10, wherein n is a + b + c + 1.

The monomeric compound of formula i (a) may have the formula:

wherein n is 2 to 12.

The monomer compound may be selected from ethylhexyl acrylate, hexyl acrylate, decyl acrylate, lauryl (dodecyl) acrylate, and isodecyl acrylate.

The monomer may have the formula:

wherein n is 4 to 14.

The monomer may have the formula:

wherein n is 4 to 14.

In another aspect, the invention provides a method for processing an electronic device or an element thereof, comprising: exposing the electronic or electrical device or component thereof to a plasma comprising the monomer compound and a crosslinking agent for a time sufficient to allow a protective crosslinked polymer coating to form on the surface of the electronic or electrical device or component thereof;

wherein the monomer compound has the formula:

wherein R is₁、R₂And R₄Each independently selected from hydrogen, optionally substituted branched or straight chain C₁-C₆Alkyl or haloalkyl or aryl optionally substituted by halogen, and R₃Selected from:

wherein each X is independently selected from hydrogen, optionally substituted branched or straight chain C₁-C₆An alkyl, haloalkyl or aryl optionally substituted with halo; and n is₁Is an integer from 1 to 27; and the crosslinker contains two or more unsaturated bonds and has a boiling point of less than 500 ℃ at standard pressure.

The monomer compounds and crosslinking agents used in this process are described in further detail above.

Typically, an electronic or electrical device or component thereof is placed in a plasma deposition chamber, a glow discharge is ignited within the chamber, and a voltage is applied in the form of a pulsed field.

Preferably 30 to 800W. Optionally, the voltage is a sequence of pulses such that the ratio on time/off time is in the range of 0.001 to 1, optionally in the range of 0.002 to 0.5. For example, the on-time may be 10 to 500 μ s, preferably 35 to 45 μ s, or 30 to 40 μ s, for example about 36 μ s, and the off-time may be 0.1 to 30ms, preferably 0.1 to 20ms, optionally 5 to 15ms, for example 6 ms. The on-time may be 35, 40, 45 mus. The off-time may be 0.1, 1,2, 3, 6, 8, 10, 15, 20, 25, or 30 ms.

The term pulse means 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 a continuous emission of plasma, but the amount of plasma cycling cycles between an upper limit (on state) and a lower limit (off state).

In another embodiment, the invention consists in a method of forming a coating on an electronic or electrical device or component thereof as defined above, the method comprising: the substrate is exposed in the chamber to a plasma comprising the monomeric compound for a sufficient time, preferably a continuous plasma, to allow a protective polymeric coating to form on the substrate, wherein the continuous plasma has a power density of at least 2W/L, preferably 20W/L, during substrate exposure.

Optionally, the voltage is applied in the form of a pulsed field for a period of 30 seconds to 90 minutes. Alternatively, the voltage is applied as a pulsed field for 5 to 60 minutes. Optionally, in an initial step, a continuous power plasma is applied to the electronic or electrical device or component thereof. The initial step may be carried out in the presence of an inert gas.

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

The monomer compound and/or the crosslinking agent are suitably in the gaseous state in the plasma. The plasma may contain only the vapors of the monomer compound and the crosslinking agent. Such vapors may be formed in situ, wherein the compound is introduced into the chamber in liquid form. The monomers 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 into the chamber by an aerosol device such as a nebulizer or the like, for example as described in WO2003/097245 and WO03/101621, the contents of which are incorporated herein by reference. In such an arrangement, no carrier gas may be required, which advantageously helps to achieve high flow rates.

In one embodiment, the monomer compound and/or cross-linking agent is in gaseous form and is fed into the plasma at a rate of 10 to 5000mg/min, depending on the volume of the chamber, while the pulsed voltage is applied.

Optionally, the plasma is generated at an average power of 0.001 to 40 watts/liter.

The crosslinking agent may be miscible with the monomer and 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. As used herein, the term "miscible" means that the crosslinking agents are soluble in the monomers and that they form a solution of uniform composition when mixed. The term "immiscible" is used to indicate that the crosslinking agent is only partially soluble or insoluble in the monomer, thus forming an emulsion or separating into two layers.

The cross-linking agent is preferably present in an amount of 10 to 60 (v/v)%, optionally 20 to 40 (v/v)%, optionally 25 to 30 (v/v)%, optionally 30 to 50 (v/v)%, depending on the particular cross-linking agent, based on the total volume of the monomer compound and cross-linking agent. Those skilled in the art familiar with this technology will appreciate that this amount will vary to some extent depending on whether the coating needs to be liquid repellent or provide a barrier to mass and electron transport. As will be understood by those skilled in the art familiar with this technology, the percentage (v/v) is the percentage that produces a stable crosslinked polymer coating and the highest water contact angle.

Electronic or electric devices or components thereof

Although the invention is beneficial in the context of a variety of substrates, in all aspects of the invention, the substrate may advantageously be an electronic substrate.

In some embodiments of the invention, the electronic substrate may comprise any piece of electronic or electrical equipment, i.e. electrical or electronic equipment. Non-limiting examples of electrical and electronic devices include communication devices such as mobile phones, smart phones and pagers, radios, and sound and audio systems such as speakers, microphones, ringer or buzzer, hearing aids, personal audio devices such as personal CD, cassette or MP3 players, televisions, DVD players including portable DVD players, video recorders, digital and other set top boxes (such as Sky), computers and related components such as laptops, notebooks, tablets or palmtop computers, Personal Digital Assistants (PDAs), keyboards or gauges, game consoles (especially handheld game consoles and the like), data storage devices, outdoor lighting systems or radio antennas, and other forms of communication devices.

In a preferred embodiment of the invention, the substrate may comprise or consist of electronic components, such as Printed Circuit Boards (PCBs), Printed Circuit Board Arrays (PCBA), transistors, resistors or semiconductor chips. The electronic component may thus be an internal component of an electronic device, such as a mobile phone. The coatings of the present invention are particularly valuable for preventing electrochemical migration in such components.

In all aspects of the present invention, the precise conditions under which the protective polymeric coating is formed in an effective manner will vary depending on a number of factors, such as, but not limited to, the monomeric compound, the crosslinking agent, the nature of the substrate, and the characteristics of the coating desired. These conditions may be determined using conventional methods, or preferably using the techniques and preferred features of the invention described herein, which act in a specific synergistic manner with the present invention.

Drawings

The invention will now be further described with reference to the following non-limiting examples and illustrative drawings, in which:

figure 1 illustrates the effect of increasing the power to monomer flow ratio of a CW plasma in a 3 liter chamber in a prior art process.

Figure 2 shows the same effect on pulsed plasma conditions.

FIG. 3 shows an example of a specimen prepared according to example 1 (thickness d 1230nm) at 10X 10 μm²A tap pattern image within the field of view (left hand side) and a contour map showing data used to calculate RMS roughness (right hand side). The Δ Z values indicated on the curves were obtained for the regions where most of the coating was represented in the figure. Peaks above the Δ Z range represent large particles and valleys below the Δ Z range represent voids or pores in the coating. The width of the peak also indicates the particle size.

Figure 4 illustrates the effect of adding a divinyl adipate crosslinker to perfluorooctyl acrylate on water contact angle from the process of a 125 liter chamber.

FIG. 5 shows the effect of the addition of a cross-linking agent according to the invention on the resistance per nano-coating.

FIG. 6 shows a 90nm thick coating prepared as described in example 3 at 2X 2 μm²A representative contour indicating the coating height variation (z-axis) (upper right graph), and a phase image indicating full substrate coverage (lower left graph); the RMS roughness of the coating was 1.65nm, and Δ z/d was 0.05.

FIG. 7 shows FTIR/ATR spectra of coatings formed according to example 5.

Detailed Description