阅读说明：本技术 电磁干扰屏蔽结构、软性电路板及其制造方法 (Electromagnetic interference shielding structure, flexible circuit board and manufacturing method thereof ) 是由 黄秋佩 洪培豪 贾孟寰 陈颖星 刘逸群 李远智 于 2019-12-02 设计创作，主要内容包括：本发明提供一种具有电磁干扰屏蔽结构的软性电路板,其包括软性电路板本体以及电磁干扰屏蔽结构。电磁干扰屏蔽结构包括接着层、绝缘层以及金属屏蔽层。绝缘层的相对两侧直接接触接着层与金属屏蔽层。电磁干扰屏蔽结构配置于软性电路板本体上。电磁干扰屏蔽结构的接着层直接接触软性电路板本体。一种电磁干扰屏蔽结构及具有电磁干扰屏蔽结构的软性电路板的制造方法亦被提出。(The invention provides a flexible circuit board with an electromagnetic interference shielding structure, which comprises a flexible circuit board body and the electromagnetic interference shielding structure. The electromagnetic interference shielding structure comprises an adhesion layer, an insulating layer and a metal shielding layer. The opposite sides of the insulating layer directly contact the adhesion layer and the metal shielding layer. The electromagnetic interference shielding structure is configured on the flexible circuit board body. The bonding layer of the electromagnetic interference shielding structure directly contacts the flexible circuit board body. An EMI shielding structure and a method for manufacturing a flexible printed circuit board having the EMI shielding structure are also provided.)

1. An electromagnetic interference shielding structure, comprising:

a bonding layer;

an insulating layer; and

a metal shielding layer, wherein opposite sides of the insulating layer directly contact the adhesion layer and the metal shielding layer.

2. The electromagnetic interference shielding structure of claim 1, further comprising:

a protective layer covering the metal shielding layer and opposite to the insulating layer.

3. The emi shielding structure of claim 1, wherein the metallic shielding layer comprises a first metallic layer and a second metallic layer, the insulating layer directly contacts the first metallic layer, and the first metallic layer is a film layer composed of a metal.

4. A flexible circuit board with an electromagnetic interference shielding structure is characterized by comprising:

a flexible circuit board body; and

the EMI shielding structure as claimed in claim 1, disposed on the FPC body, wherein the adhesion layer of the EMI shielding structure directly contacts the FPC body.

5. The flexible circuit board with EMI shielding structure according to claim 4, further comprising:

a conductive via passing through the EMI shielding structure, wherein:

the flexible circuit board body comprises a flexible substrate and a circuit layer, and the conductive through hole is electrically connected to the metal shielding layer and part of the circuit layer.

6. A flexible circuit board having EMI shielding structure according to claim 5, wherein the side walls of said conductive vias are substantially perpendicular to said flexible circuit board body.

7. A flexible circuit board having EMI shielding structure according to claim 5, wherein a top surface of said conductive via is substantially flush with a top surface of said EMI shielding structure.

8. The FPC of claim 5, wherein the FPC further comprises a conductive layer, and the flexible substrate is disposed between the circuit layer and the conductive layer.

9. A method for manufacturing a flexible circuit board with an electromagnetic interference shielding structure is characterized by comprising the following steps: electromagnetic interference shielding structure, flexible circuit board and manufacturing method thereof

Providing a flexible circuit board body;

the EMI shielding structure of claim 1 is bonded to the FPC body, and the adhesion layer of the EMI shielding structure directly contacts the FPC body.

10. The method as claimed in claim 9, wherein the flexible printed circuit board includes a flexible substrate and a circuit layer, and the method further comprises:

and at least carrying out laser burning on the electromagnetic interference shielding structure to form a conductive through hole penetrating through the electromagnetic interference shielding structure, wherein the conductive through hole is electrically connected with the metal shielding layer and part of the circuit layer.

Technical Field

The present invention relates to an electromagnetic interference shielding structure, an electronic device and a method for manufacturing the same, and more particularly, to an electromagnetic interference shielding structure applied to a flexible printed circuit board, a flexible printed circuit board having the electromagnetic interference shielding structure, and a method for manufacturing the same.

Background

With the development of high-frequency signal transmission, a multi-layer printed circuit board (PCB, which may be simply referred to as a multi-layer board) is used in many electronic products, and wiring of an inner layer (i.e., not located at the topmost layer or the bottommost layer) is used for high-frequency signal transmission.

Multilayer printed circuit boards often have a bonding sheet. The adhesive sheet is mostly made of glass fibers or other fiber-impregnated resin through partial polymerization. Therefore, the electronic product having the aforementioned multilayer printed circuit board is thick.

Disclosure of Invention

The invention provides an electromagnetic interference shielding structure, a flexible circuit board with the electromagnetic interference shielding structure and a manufacturing method thereof.

The electromagnetic interference shielding structure comprises an adhesion layer, an insulating layer and a metal shielding layer. The opposite sides of the insulating layer directly contact the adhesion layer and the metal shielding layer.

In an embodiment of the invention, the emi shielding structure further includes a protective layer. The protective layer covers the metal shielding layer and is opposite to the insulating layer.

In an embodiment of the invention, the metal shielding layer includes a first metal layer and a second metal layer. The insulating layer directly contacts the first metal layer. The first metal layer is a film layer composed of metal.

The flexible circuit board with the electromagnetic interference shielding structure comprises a flexible circuit board body and the electromagnetic interference shielding structure. The electromagnetic interference shielding structure is configured on the flexible circuit board body. The bonding layer of the electromagnetic interference shielding structure directly contacts the flexible circuit board body.

In an embodiment of the invention, the flexible circuit board with the emi shielding structure further includes a conductive via. The conductive via penetrates the electromagnetic interference shielding structure. The flexible circuit board body comprises a flexible substrate and a circuit layer. The conductive through hole is electrically connected with the metal shielding layer and part of the circuit layer.

In an embodiment of the invention, the sidewall of the conductive via is substantially perpendicular to the flexible circuit board body.

In an embodiment of the present invention, a top surface of the conductive via is substantially flush with a top surface of the EMI shielding structure.

In an embodiment of the invention, the flexible circuit board body further includes a conductive layer, and the flexible substrate is located between the circuit layer and the conductive layer.

The manufacturing method of the flexible circuit board with the electromagnetic interference shielding structure comprises the following steps. A flexible printed circuit board is provided. The electromagnetic interference shielding structure is jointed with the flexible circuit board body, and the adhesion layer of the electromagnetic interference shielding structure is directly contacted with the flexible circuit board body.

In an embodiment of the invention, the flexible circuit board body includes a flexible substrate and a circuit layer. The manufacturing method of the flexible circuit board with the electromagnetic interference shielding structure further comprises the following steps. And at least carrying out laser burning on the electromagnetic interference shielding structure to form a conductive through hole penetrating through the electromagnetic interference shielding structure, wherein the conductive through hole is electrically connected with the metal shielding layer and part of the circuit layer.

Based on the above, the overall thickness of the flexible circuit board with the electromagnetic interference shielding structure of the invention can be thinner, and the material cost can be lower.

In order to make the aforementioned and other features and advantages of the invention more comprehensible, embodiments accompanied with figures are described in detail below.

Drawings

FIGS. 1A to 1E are schematic partial sectional views illustrating a method for manufacturing a flexible printed circuit board having an EMI shielding structure according to a first embodiment of the present invention;

fig. 2 is a schematic partial cross-sectional view of a flexible circuit board having an emi shielding structure according to a second embodiment of the invention.

The reference numbers illustrate:

100. 200: flexible circuit board with electromagnetic interference shielding structure

500: electromagnetic interference shielding structure

500 a: the top surface

510: adhesive layer

520: insulating layer

520 a: first insulating surface

520 b: second insulating surface

530: metal shielding layer

531: a first metal layer

531 t: thickness of

532: second metal layer

532 t: thickness of

540: protective layer

551: opening of the container

551 c: side wall

552: conductive vias

552 a: the top surface

552 c: side wall

110. 210: flexible circuit board body

111: line layer

112: flexible substrate

213: conductive layer

60: laser device

Detailed Description

The foregoing and other technical and scientific aspects, features and utilities of the present invention will be apparent from the following detailed description of various embodiments, which is to be read in connection with the accompanying drawings. Directional terms as referred to in the following examples, for example: "upper", "lower", "front", "rear", "left", "right", etc., refer only to the orientation of the figures. Accordingly, the directional terminology is used for purposes of illustration and is in no way limiting. Also, in the following embodiments, the same or similar elements will be given the same or similar reference numerals.

Fig. 1A to fig. 1E are schematic partial cross-sectional views illustrating a method for manufacturing a flexible circuit board 100 having an emi shielding structure according to a first embodiment of the invention.

Referring to fig. 1A, a flexible circuit board body 110 is provided. The flexible circuit board body 110 may include a flexible substrate 112 and a circuit layer 111. In the present embodiment, the flexible circuit board body 110 is, for example, a single-sided flexible printed circuit board (which may be referred to as a single-sided board), but the invention is not limited thereto. That is, in the embodiment, the flexible circuit board body 110 is not a multi-layer printed circuit board (PCB, which may be simply referred to as a multi-layer board).

It is noted that, in fig. 1A, only a portion of the circuit layer 111 is exemplarily shown. The routing (layout) in the routing layer 111 can be adjusted according to design requirements, and is not limited in the present invention. In other words, in another cross section not shown, only a portion of the circuit layer 111 may be covered on the flexible substrate 112; in another cross section not shown, the circuit layer 111 may not be formed on the flexible substrate 112.

Referring to fig. 1B to fig. 1C, the emi shielding structure 500 is bonded to the flexible circuit board body 110.

The emi shielding structure 500 includes a bonding layer 510, an insulating layer 520, and a metal shielding layer 530. The insulating layer 520 has a first insulating surface 520a and a second insulating surface 520b opposite to each other. The first insulating surface 520a of the insulating layer 520 directly contacts the adhesive layer 510. The second insulating surface 520b of the insulating layer 520 directly contacts the metal shielding layer 530.

In this embodiment, the emi shielding structure 500 may further include a protective layer 540. The protective layer 540 covers the metal shielding layer 530. The protective layer 540 is opposite to the insulating layer 520. In other words, the metal shielding layer 530 is located between the protection layer 540 and the insulating layer 520. The protection layer 540 may be an insulating material having a hardness greater than that of metal, but the invention is not limited thereto. The protective layer 540 may reduce the possibility of damage and/or oxidation of the metal shielding layer 530.

In this embodiment, the metal shielding layer 530 may include a first metal layer 531 and a second metal layer 532. The second insulating surface 520b of the insulating layer 520 directly contacts the first metal layer 531, and the first metal layer 531 is a film layer composed of metal. In other words, the first metal layer 531 may not be a film layer formed of a conductive adhesive. The conductive adhesive is, for example, a composite material (e.g., silver paste, aluminum paste) comprising a binder (e.g., resin) and a conductive material (e.g., metal powder). That is, since the emi shielding structure 500 does not have the conductive adhesive, the thickness thereof can be thin and the material cost can be low.

In an embodiment, a bonding force between the first metal layer 531 and the insulating layer 520 is greater than a bonding force between the second metal layer 532 and the insulating layer 520, and an electrical conductivity (electrical conductivity) of the second metal layer 532 is greater than that of the first metal layer 531. For example, the insulating layer 520 is made of Polyimide (PI), the first metal layer 531 is made of nickel, and the second metal layer 532 is made of copper, but the invention is not limited thereto.

In an embodiment, the thickness 532t of the second metal layer 532 may be greater than the thickness 531t of the first metal layer 531. The thickness 532t of the second metal layer 532 may be 10 times to 50 times the thickness 531t of the first metal layer 531, but the present invention is not limited thereto.

In one embodiment, the first metal layer 531 may be referred to as a metal adhesive layer (metallic adhesive layer), but the invention is not limited thereto.

In one embodiment, the material of the adhesion layer 510 may comprise a curable material. For example, in fig. 1B, the material in the adhesion layer 510 may be in a semi-cured or uncured state. After the semi-cured or uncured material is contacted with the flexible circuit board body 110, a curing step (e.g., photo-curing, thermal-curing and/or static curing) may be performed according to the material in the adhesive layer 510, so that the emi shielding structure 500 and the flexible circuit board body 110 are tightly combined as shown in fig. 1C.

Referring to fig. 1C to fig. 1D, in an embodiment, after the electromagnetic interference shielding structure 500 is combined with the flexible circuit board body 110, an opening 551 exposing the circuit layer 111 may be formed on the electromagnetic interference shielding structure 500.

In one embodiment, the opening 551 may be formed by laser ablation by the laser device 60. Compared with the opening formed by wet etching, the opening 551 formed by the laser device 60 is less prone to lateral etching, and therefore undercut (undercut) is reduced. That is, the sidewall 551c of the opening 551 can be substantially perpendicular to the surface of the flexible circuit board body 110 (e.g., perpendicular to the surface of the flexible substrate 112 of the flexible circuit board body 110).

In addition, the opening 551 can be formed directly through the laser device 60 according to design requirements. That is, the laser device 60 does not need to form the opening 551 using a photomask. Therefore, the design of the position of the opening 551 has better changeability, and can be adjusted quickly according to the design requirement.

Referring to fig. 1D to fig. 1E, in an embodiment, after forming the opening 551, a conductive material may be filled in the opening 551 to form a conductive via 552. The conductive material may be silver paste, aluminum paste, solder paste, other suitable conductive paste or conductive paste. The conductive via 552 electrically connects the metal shielding layer 530 of the emi shielding structure 500 and the portion of the circuit layer 111 exposed by the opening 551.

In one embodiment, the shape of the conductive via 552 substantially corresponds to the profile of the opening 551. In other words, the sidewall 552c of the conductive via 552 can be substantially perpendicular to the surface of the flexible circuit board body 110 (e.g., perpendicular to the surface of the flexible substrate 112 of the flexible circuit board body 110).

In an embodiment, a top surface 552a of the conductive via 552 may be substantially flush with a top surface 500a of the emi shielding structure 500.

The manufacturing of the flexible circuit board 100 with the emi shielding structure of the present embodiment can be substantially completed through the above processes. The flexible circuit board 100 with the emi shielding structure includes a flexible circuit board body 110 and an emi shielding structure 500. The emi shielding structure 500 is disposed on the flexible circuit board body 110. The emi shielding structure 500 includes a bonding layer 510, an insulating layer 520, and a metal shielding layer 530. The first insulating surface 520a of the insulating layer 520 directly contacts the adhesive layer 510. The second insulating surface 520b of the insulating layer 520 directly contacts the metal shielding layer 530. The adhesion layer 510 of the emi shielding structure 500 directly contacts the flexible circuit board body 110.

In this embodiment, the flexible circuit board 100 with the emi shielding structure may further include a conductive via 552. A conductive via 552 extends through emi shielding structure 500. The conductive vias 552 are electrically connected to the metal shielding layer 530 and a portion of the circuit layer 111 of the flexible circuit board body 110.

In an embodiment, a portion of the circuit layer 111 electrically connected to the conductive via 552 may be grounded, but the invention is not limited thereto.

Fig. 2 is a schematic partial cross-sectional view of a flexible circuit board 200 having an emi shielding structure according to a second embodiment of the invention.

In the present embodiment, the manufacturing method of the flexible circuit board 200 with the emi shielding structure is similar to the manufacturing method of the flexible circuit board 100 with the emi shielding structure of the first embodiment, and similar components are denoted by the same reference numerals and have similar functions, materials or forming manners, and descriptions thereof are omitted.

The flexible printed circuit 200 with emi shielding structure includes a flexible printed circuit body 210 and an emi shielding structure 500. The flexible circuit board body 210 may include a flexible substrate 112, a circuit layer 111 and a conductive layer 213. The flexible substrate 112 is located between the circuit layer 111 and the conductive layer 213.

In one embodiment, the conductive layer 213 is a film layer made of metal. For example, the material of the conductive layer 213 is copper, but the invention is not limited thereto.

In an embodiment, the conductive layer 213 may be a full-surface film, but the invention is not limited thereto. In another embodiment, the conductive layer 213 may have a corresponding pattern, and the pattern of the conductive layer 213 may be adjusted according to design requirements. In other words, in another cross section not shown, only a portion of the conductive layer 213 may cover the flexible substrate 112; in another cross section not shown, the conductive layer 213 may not be present on the flexible substrate 112.

In the present embodiment, the flexible circuit board body 210 is, for example, a double-sided flexible printed circuit board (double-sided flexible printed circuit board). That is, in the embodiment, the flexible circuit board body 210 is not a multi-layer printed circuit board (PCB, which may be simply referred to as a multi-layer board).

In an embodiment, at least a portion of the conductive layer 213 may be grounded. In other words, the conductive layer 213 may serve as an electromagnetic interference shield, but the present invention is not limited thereto.

In summary, the thickness of the emi shielding structure of the present invention can be thinner, and the material cost can be lower. In addition, the flexible circuit board with the electromagnetic interference shielding structure can be thinner in overall thickness and lower in material cost.

Although the present invention has been described with reference to the above embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention.