CN219999665U

CN219999665U - Flexible circuit board with support body

Info

Publication number: CN219999665U
Application number: CN202320658876.XU
Authority: CN
Inventors: 和建锋; 侯宁; 李彪
Original assignee: Avary Holding Shenzhen Co Ltd; Qing Ding Precision Electronics Huaian Co Ltd
Current assignee: Avary Holding Shenzhen Co Ltd; Qing Ding Precision Electronics Huaian Co Ltd
Priority date: 2023-03-22
Filing date: 2023-03-22
Publication date: 2023-11-10
Anticipated expiration: 2033-03-22

Abstract

The utility model provides a flexible circuit board with a support body, which comprises a substrate and the support body. The support body comprises a support plate and a support column arranged on the support plate, the support column is accommodated in the through hole of the base plate, and the support plate is fixed on one side of the second outer circuit layer of the base plate, which is away from the base material layer. According to the utility model, through holes are formed in the positions, adjacent to the bonding pads, of the substrate, the support columns are embedded in the through holes, and play a supporting role in the crimping process, so that the bonding pads can be prevented from moving downwards due to the fact that the substrate layer and the dielectric layer are molten and the acting force of the hot-pressing head is downward due to the high temperature of the hot-pressing head in the welding process, and the phenomena of poor conduction and/or poor insulation of upper and lower conductive circuit layers are improved.

Description

Flexible circuit board with support body

Technical Field

The utility model relates to a flexible circuit board with a support body.

Background

At present, the connection mode between a flexible circuit board (FPC, also called a soft board) and a hard circuit board (also called a hard board) is Hot bar (also called pulse Hot-press welding, also called a Haba machine in industry). The Hot bar heats the Hot pressing head by utilizing huge Joule heat generated when pulse current flows through materials with high resistance characteristics such as molybdenum, titanium and the like (the temperature of the heated Hot pressing head can reach more than 300 ℃), and then the Hot pressing head heats and melts solder paste on the hard plate so as to achieve the purpose of welding the hard plate and the soft plate.

However, when the soldered flexible circuit board has an LCP (liquid crystal polymer) material with a heat distortion temperature of 180-250 ℃, the LCP material will become molten due to the high temperature of the thermal head (up to 300 ℃) during soldering, and the downward force of the thermal head will sink the pads (pads) on the surface of the flexible circuit board, resulting in poor conduction and/or insulation of the upper and lower conductive circuit layers.

Disclosure of Invention

In view of the above, the present utility model provides a flexible circuit board with a supporting body to solve the problem of poor conduction and/or poor insulation of a conductive circuit layer caused by sinking of a bonding pad.

An embodiment of the present utility model provides a flexible circuit board having a support body, including:

the substrate comprises a base material layer and at least two conductive circuit layers arranged on the surface of the base material layer, and a dielectric layer is arranged between every two adjacent conductive circuit layers; the conductive circuit layers positioned at the outermost side of the substrate are a first outer circuit layer and a second outer circuit layer, and the first outer circuit layer comprises a bonding pad; the substrate comprises a through hole, the through hole penetrates through the second outer circuit layer, the base material layer and the dielectric layer on the inner side of the first outer circuit layer, and the through hole is exposed from the first outer circuit layer and is close to the bonding pad; and

the support body, the support body includes the backup pad and locates support column in the backup pad, the support column accept in the through-hole, the backup pad is fixed in the second outside circuit layer deviates from one side of substrate layer.

In one embodiment, a first protection layer is disposed on a surface of the first outer circuit layer facing away from the substrate layer, and the bonding pad is exposed from the first protection layer.

In one embodiment, a second protective layer is disposed on a surface of the second outer circuit layer facing away from the substrate layer. The support plate is fixed on the surface of the second protective layer, which faces away from the second outer line layer, and the through holes penetrate through the second protective layer.

In one embodiment, the supporting plate is fixed on the surface of the second protection layer, which faces away from the second outer circuit layer, through an adhesive layer.

In one embodiment, the aperture of the through hole is 0.25mm to 0.35mm.

In one embodiment, the support post has a diameter of 0.20mm to 0.30mm.

In one embodiment, the surface of the support post facing away from the support plate is 0 μm to 30 μm lower than the surface of the bonding pad facing away from the substrate layer.

In one embodiment, the support further comprises a plurality of side walls extending from the edge of the support plate in the same direction, and the extending direction of the side walls is the same as the extending direction of the support columns.

In one embodiment, the material of the support body includes polyetheretherketone.

In one embodiment, the material of the substrate layer includes a liquid crystal polymer.

According to the utility model, through holes are formed in the positions, adjacent to the bonding pads, of the substrate, the support columns are embedded in the through holes, and play a supporting role in the crimping process, so that the bonding pads can be prevented from moving downwards due to the fact that the substrate layer and the dielectric layer are molten and the acting force of the hot-pressing head is downward due to the high temperature of the hot-pressing head in the welding process, and the phenomena of poor conduction and/or poor insulation of upper and lower conductive circuit layers are improved.

Drawings

Fig. 1 is a schematic cross-sectional view of a flexible circuit board according to an embodiment of the utility model.

Fig. 2 is a schematic cross-sectional view of a substrate of the flexible circuit board shown in fig. 1 in an embodiment.

Fig. 3 is a schematic structural diagram of a support body of the flexible circuit board shown in fig. 1 in an embodiment.

Fig. 4 is a top view of the flexible circuit board shown in fig. 1.

Fig. 5 is a cross-sectional view of the flexible circuit board shown in fig. 4 along V-V.

Fig. 6 is a top view of the substrate shown in fig. 2.

Fig. 7 is a cross-sectional view of the substrate board shown in fig. 6 along VII-VII.

Description of the main reference signs

Flexible circuit board 100

Substrate 10

Support body 20

Substrate layer 11

Conductive trace layer 12

Dielectric layer 13

First conductive line layer 121

Second conductive line layer 122

Third conductive line layer 123

Fourth conductive trace layer 124

Adhesive layer 14

First outer circuit layer 110

Second outer line layer 120

Pad 130

Through hole 101

Conductive structures 102, 103

Support plate 21

Support column 22

Side wall 23

First protective layer 15

Second protective layer 16

Adhesive layer 17

The following detailed description will further illustrate embodiments of the utility model in conjunction with the above-described drawings.

Detailed Description

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which embodiments of the utility model belong. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of embodiments of the utility model.

It will be understood that when a layer is referred to as being "on" another layer, it can be directly on the other layer or intervening layers may be present therebetween. In contrast, when a layer is referred to as being "directly on" another layer, there are no intervening layers present.

Embodiments of the present utility model are described herein with reference to cross-sectional illustrations that are schematic illustrations of idealized embodiments (and intermediate configurations) of the present utility model. Thus, differences in the shapes of the illustrations as a result, of manufacturing processes and/or tolerances, are to be expected. Thus, embodiments of the utility model should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. The regions illustrated in the figures are merely schematic in nature and their shapes are not intended to illustrate the actual shape of a device and are not intended to limit the scope of the present utility model.

Some embodiments of the present utility model are described in detail below with reference to the accompanying drawings. The following embodiments and features of the embodiments may be combined with each other without collision.

Referring to fig. 1 to 7, the present utility model provides a flexible circuit board 100, which includes a substrate 10 and a support 20.

The substrate 10 is a circuit board with conductive lines, and the manufacturing method of the substrate 10 may be a manufacturing method of a circuit board in the prior art, which is not described herein. As shown in fig. 1 and 2, the substrate 10 includes a base material layer 11 and at least two conductive circuit layers 12 disposed on the surface of the base material layer 11, and a dielectric layer 13 is disposed between two adjacent conductive circuit layers 12. In this embodiment, the material of the substrate layer 11 is a Liquid Crystal Polymer (LCP). In other embodiments, the material of the substrate layer 11 may be other flexible materials with a lower melting point (less than 300 ℃). The material of the dielectric layer 13 may be, but is not limited to, polyimide, polypropylene, liquid crystal polymer, polyether ether ketone, polyethylene terephthalate, polyethylene naphthalate, etc.

In this embodiment, as shown in fig. 1 and 2, the substrate 10 has four conductive trace layers 12. The four conductive circuit layers 12 are respectively: the first conductive circuit layer 121 and the second conductive circuit layer 122 are disposed on two opposite surfaces of the substrate layer 11, the third conductive circuit layer 123 is disposed on a side of the first conductive circuit layer 121 facing away from the substrate layer 11, and the fourth conductive circuit layer 124 is disposed on a side of the second conductive circuit layer 122 facing away from the substrate layer 11. The first conductive trace layer 121 and the third conductive trace layer 123 may be electrically connected by a conductive structure 102, and the second conductive trace layer 122 and the fourth conductive trace layer 124 may be electrically connected by a conductive structure 102, where the conductive structure 102 may be, but is not limited to, a conductive via. The substrate 10 may also have a conductive structure 103 to electrically connect the first conductive trace layer 121, the second conductive trace layer 122, the third conductive trace layer 123, and the fourth conductive trace layer 124. Dielectric layers 13 are disposed between adjacent first and third conductive trace layers 121 and 123 and between adjacent second and fourth conductive trace layers 122 and 124.

In some embodiments, as shown in fig. 1 and 2, the dielectric layer 13 may be disposed between two adjacent conductive trace layers 12 through an adhesive layer 14. The adhesive layer 14 may be formed of an insulating adhesive commonly used in the art, and the material thereof is not limited in the present utility model.

In other embodiments, the substrate 10 may have only the first conductive trace layer 121 and the second conductive trace layer 122 on opposite surfaces of the substrate layer 11. In other embodiments, the build-up of the substrate 10 shown in fig. 2 may be continued, forming a circuit board with more conductive trace layers 12.

In the present utility model, the conductive trace layer 12 located at the outermost side of the substrate 10 is referred to as a first outer trace layer 110 and a second outer trace layer 120. It is understood that the outermost conductive trace layer 12 refers to the trace layer that is outermost of all conductive trace layers 12, and that no other conductive trace layer 12 is present outside of the conductive trace layer 12 (the side away from the inner substrate layer 11). In this embodiment, the third conductive line layer 123 is the first outer line layer 110, and the fourth conductive line layer 124 is the second outer line layer 120.

As shown in fig. 4, the first outer circuit layer 110 includes pads 130, and the number of the pads 130 may be plural. The pads 130 may be used to electrically connect the flexible circuit board 100 with external components. As shown in fig. 2, 6 and 7, the substrate 10 includes a through hole 101, the through hole 101 penetrates the second outer wiring layer 120, the base material layer 11 and the dielectric layer 13 inside the first outer wiring layer 110 (the side close to the base material layer 11 inside), and the through hole 101 is exposed from the first outer wiring layer 110 and is close to the pad 130. The number of the through holes 101 may be plural.

As shown in fig. 1 and 3, the support body 20 includes a support plate 21 and a support column 22 provided on the support plate 21. As shown in fig. 1 and 5, the support column 22 is accommodated in the through hole 101, and the support plate 21 is fixed to a side of the second outer circuit layer 120 facing away from the substrate layer 11. The support column 22 may be substantially cylindrical, and may be provided with one or more rows on the support plate 21, and may correspond to the through holes 101.

By providing the through hole 101 at a position adjacent to the bonding pad 130, the support column 22 is embedded in the through hole 101, and the support column 22 plays a supporting role in the crimping process, so that the bonding pad 130 can be prevented from moving downwards due to the melting of the substrate layer 11 and the dielectric layer 13 caused by the high temperature of the hot press head and the downward acting force of the hot press head in the welding process, and the phenomena of poor conduction and/or poor insulation of the upper and lower conductive circuit layers 12 are improved.

As shown in fig. 1 and 3, in some embodiments, the support 20 further includes a plurality of side walls 23 extending from the edge of the support plate 21 in the same direction, and the extending direction of the side walls 23 is the same as the extending direction of the support columns 22. In this embodiment, the support 20 includes three side walls 23. The three side walls 23 are abutted against the edge of the substrate 10, so as to enhance the connection stability between the substrate 10 and the support 20. The sidewall 23 may be bonded to the substrate 10 by the adhesive layer 17.

Further, the support column 22 may have a diameter of 0.20mm to 0.30mm. In this embodiment, the support column 22 has a diameter of 0.25mm. The aperture of the through hole 101 may be 0.25mm to 0.35mm, and in this embodiment, the aperture of the through hole 101 is 0.30mm. Thus, the support column 22 can be fitted in the through hole 101 without shaking in the through hole 101. The support post 22 and the through hole 101 may also be an interference fit.

In some embodiments, the material of the support 20 may be Polyetheretherketone (PEEK). PEEK is a high-performance polymer, the melting point is 341 ℃, the PEEK cannot be melted during Hot pressing at Hot bar, and the PEEK is insulating and high in hardness, so that a strong support can be provided for the bonding pad 130. The support 20 may be formed by heating polyetheretherketone to a molten state and then injection molding the support through a mold.

In some embodiments, as shown in fig. 5, the surface of the support post 22 facing away from the support plate 21 (i.e., the top surface in fig. 5) is lower than the surface of the bonding pad 130 facing away from the substrate layer 11 (i.e., the top surface in fig. 5). Specifically, the top surface of the support post 22 may be 0 μm to 30 μm lower than the top surface of the pad 130. Thus, a certain deformation space can be provided for the bonding pad 130, and a better supporting effect is achieved for the bonding pad 130. It will be appreciated that when the top surface of the support post 22 is 0 μm lower than the top surface of the pad 130, this means that the top surface of the support post 22 is flush with the top surface of the pad 130.

As shown in fig. 1 and 2, in some embodiments, the substrate 10 further includes a first protective layer 15 and a second protective layer 16. The first protective layer 15 may be disposed on a surface of the first outer circuit layer 110 facing away from the substrate layer 11 through an adhesive layer 14, and the second protective layer 16 may be disposed on a surface of the second outer circuit layer 120 facing away from the substrate layer 11 through an adhesive layer 14. As shown in fig. 4 and 6, the first protective layer 15 does not cover the pad 130 and the via 101, and the pad 130 and the via 101 are exposed from the first protective layer 15. The first protective layer 15 and the second protective layer 16 may be cover-lay (CVL) layers for protecting the conductive line layer 12 of the substrate 10 from outside moisture or foreign matter scratch, etc.

It will be appreciated that the support plate 21 is fixed to the outside of the base plate 10. When the substrate 10 further has the structure of the second protective layer 16, the support plate 21 is fixed to the outer surface of the second protective layer 16 located at the outermost side (i.e., the surface facing away from the second outer circuit layer 120), and the through hole 101 further penetrates the second protective layer 16.

Further, the supporting plate 21 may be fixed to a surface of the second protective layer 16 facing away from the second outer circuit layer 120 through an adhesive layer 17. The side wall 23 of the support 20 may be bonded to the substrate 10 by the adhesive layer 17. The material of the adhesive layer 17 may be an insulating adhesive commonly used in the art.

In some embodiments, the supporting plate 21 may also be directly pressed onto the surface of the second protection layer 16 facing away from the second outer circuit layer 120 by a jig.

According to the utility model, through holes 101 are formed in the position, adjacent to the bonding pads 130, on the substrate 10, the support columns 22 are embedded in the through holes 101, and the support columns 22 play a supporting role in the crimping process, so that the bonding pads 130 can be prevented from moving downwards due to the fact that the substrate layer 11 and the dielectric layer 13 are melted and the downward acting force of the hot pressing head is caused by the high temperature of the hot pressing head in the welding process, and the phenomenon of poor conduction and/or poor insulation of the upper and lower conductive circuit layers 12 is improved.

The above description is of some embodiments of the utility model, but in practice the application is not limited to these embodiments. Other modifications and variations to the present utility model will be apparent to those of ordinary skill in the art in light of the present teachings.

Claims

1. A flexible circuit board having a support, comprising:

2. The flexible circuit board of claim 1, wherein a surface of the first outer circuit layer facing away from the substrate layer is provided with a first protective layer from which the pads are exposed.

3. The flexible circuit board of claim 1, wherein a second protective layer is disposed on a surface of the second outer circuit layer facing away from the substrate layer, the support plate is fixed to a surface of the second protective layer facing away from the second outer circuit layer, and the through hole further penetrates through the second protective layer.

4. The flexible circuit board of claim 3, wherein the support plate is secured to a surface of the second protective layer facing away from the second outer circuit layer by an adhesive layer.

5. The flexible circuit board of claim 1, wherein the aperture of the through hole is 0.25mm to 0.35mm.

6. The flexible circuit board of claim 1 wherein the support posts have a diameter of 0.20mm to 0.30mm.

7. The flexible circuit board of claim 1, wherein a surface of the support posts facing away from the support plate is 0 μιη to 30 μιη lower than a surface of the pads facing away from the substrate layer.

8. The flexible circuit board of claim 1 wherein the support body further comprises a plurality of side walls extending in the same direction from the edge of the support board, the side walls extending in the same direction as the support columns.

9. The flexible circuit board of claim 1, wherein the support is polyetheretherketone.

10. The flexible circuit board of claim 1, wherein the substrate layer is made of a liquid crystal polymer.