CN218868428U

CN218868428U - Flexible circuit board connecting structure

Info

Publication number: CN218868428U
Application number: CN202222741983.7U
Authority: CN
Inventors: 陈文强
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: 2022-10-18
Filing date: 2022-10-18
Publication date: 2023-04-14
Anticipated expiration: 2032-10-18

Abstract

The application provides a flexible circuit board connecting structure, which comprises a flexible circuit board and a connecting sheet arranged on one side of the flexible circuit board, wherein the flexible circuit board comprises a substrate layer, a circuit layer arranged on one side of the substrate layer and a copper column arranged on the surface of the circuit layer; the connecting piece penetrates through the connecting piece and is provided with at least one through hole, a groove is formed in one surface of the connecting piece in a concave mode, the groove is communicated with the through hole, part of the copper column penetrates through the through hole and is bent, and the bent part of the copper column is arranged in the groove. The flexible circuit board connecting structure does not need to use tin paste, and has high bonding strength and better reliability by adopting a mechanical connection mode; a welding process is not needed, so that the cost can be saved; the structure of the flexible circuit board is not required to be damaged, and the surface is smooth, so that the stability and the reliability of subsequent installation and the whole structure are facilitated.

Description

Flexible circuit board connecting structure

Technical Field

The application relates to the technical field of flexible circuit boards, in particular to a flexible circuit board connecting structure.

Background

At present, the flexible circuit board replaces the traditional wiring harness to be connected and is widely applied to the power battery module, and the flexible circuit board can not be directly welded and fixed with components due to the limitation of the material of the flexible circuit board, and usually a nickel sheet is required to be arranged on the flexible circuit board for auxiliary connection. In the prior art, a nickel sheet is usually directly soldered to a solder pad of a flexible circuit board through solder paste, or a protruding nickel tooth is disposed on the nickel sheet, and the nickel tooth penetrates through the flexible circuit board and is bent and attached to the back of the flexible circuit board. The former solder paste welding has general bonding strength, is easy to fall off under the action of external force, has the problems of insufficient solder, empty solder, bubbles and the like, and has low reliability; in the latter, the nickel teeth are partially bent and formed on the back surface of the flexible circuit board, so that the flatness is insufficient, the subsequent installation and the overall stability are not facilitated, and the nickel teeth are unstable in penetrating and electric connection, so that the reliability of the whole structure is not facilitated.

SUMMERY OF THE UTILITY MODEL

In view of this, the present application provides a flexible printed circuit board connection structure with high bonding strength and good reliability.

An embodiment of the application provides a flexible circuit board connecting structure, which comprises a flexible circuit board and a connecting sheet arranged on one side of the flexible circuit board, wherein the flexible circuit board comprises a substrate layer, a circuit layer arranged on one side of the substrate layer and a copper column arranged on the surface of the circuit layer; the connecting piece penetrates through the connecting piece and is provided with at least one through hole, a groove is formed in one surface of the connecting piece in a concave mode, the groove is communicated with the through hole, part of the copper column penetrates through the through hole and is bent, and the bent part of the copper column is arranged in the groove.

In some possible embodiments, the copper pillar includes a first portion and a second portion connected to each other, the first portion is attached to an inner wall of the through hole, the second portion is bent relative to the first portion, and the second portion is disposed in the slot;

the surface of the second part, which is deviated from the connecting sheet, is flush with the surface of the connecting sheet, which is deviated from the flexible circuit board.

In some possible embodiments, the connecting sheet is further provided with a groove, and the bottom of one end of the groove, which is far away from the through hole, is recessed to form the groove;

the copper column further comprises a third portion connected to the second portion, and the third portion is bent and arranged in the groove.

In some possible embodiments, the width of the groove is equal to the width of the third portion.

In some possible embodiments, the number of the copper columns is 2n, n is greater than or equal to 1, and n is a positive integer;

every two have a clearance and every two between the copper post symmetry sets up, 2n the copper post encircles the even interval in clearance sets up.

In some possible embodiments, 2n copper columns are taken as a group, and the flexible circuit board comprises m groups of copper columns, wherein m is greater than or equal to 1 and is a positive integer;

the quantity of through-hole is m, every group the copper post corresponds one the through-hole sets up.

In some possible embodiments, the circuit layer includes a pad, the copper pillar is disposed on a surface of the pad facing away from the substrate layer, one end of the connecting sheet is disposed on the surface of the pad, and the other end of the connecting sheet extends out of the flexible circuit board.

In some possible embodiments, the flexible wiring board further includes a cover film covering a portion of the wiring layer other than the land.

In some possible embodiments, the connecting sheet is flush with the surface of the end of the bonding pad facing the cover film;

the cover film is in contact with the end portions of the bonding pad and the connecting sheet so as to seal the connecting portion of the connecting sheet and the bonding pad.

In some possible embodiments, the material of the substrate layer is polyimide.

The application provides a flexible line way board connection structure through flexible line way board surface sets up the copper post, and set up through-hole and fluting in the connection piece, can make through the crimping the copper post passes the through-hole, partial lock joint in the fluting to realize fixed connection. The flexible circuit board connecting structure does not need to use tin paste, and has high bonding strength and better reliability by adopting a mechanical connection mode; a welding process is not needed, so that the cost can be saved; the structure of the flexible circuit board is not required to be damaged, and the surface is smooth, so that the stability and the reliability of subsequent installation and the whole structure are facilitated.

In addition, through add the recess at the connection piece for after the copper post crimping with the bonding strength of connection piece is higher, overall structure's reliability and stability are better.

Drawings

Fig. 1 is a schematic cross-sectional view of a flexible printed circuit board connection structure according to a first embodiment of the present disclosure.

Fig. 2 is a partially enlarged plan view of the flexible wiring board connection structure shown in fig. 1.

Fig. 3 is a schematic cross-sectional view of the flexible wiring board shown in fig. 1.

Fig. 4 is a schematic cross-sectional view of the tab shown in fig. 1.

Fig. 5 is a schematic cross-sectional view of a flexible printed circuit board connection structure according to a second embodiment of the present application.

Fig. 6 is a schematic cross-sectional view of the tab shown in fig. 5.

Fig. 7 is a schematic diagram of a process of forming the flexible wiring board connection structure shown in fig. 5 by crimping.

Description of the main elements

Flexible circuit

board connecting structure

100, 200

Flexible wiring board 10

Substrate layer 11

Line layer 12

Pad 121

Cover film 13

Copper pillar 14

First portion 141

Second portion 142

Third part 143

Gap 15

Connecting piece 20

First surface 201

Second surface 202

Through hole 21

Slot 22

Groove 23

Crimping die 300

The following detailed description will further illustrate the present application in conjunction with the above-described figures.

Detailed Description

The technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments of the present application, and not all embodiments.

In the description of the present application, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present application. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or to implicitly indicate the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

To further explain the technical means and effects of the present application for achieving the intended purpose, the following detailed description is given to the present application in conjunction with the accompanying drawings and preferred embodiments.

Referring to fig. 1, a flexible printed circuit board connection structure 100 according to a first embodiment of the present disclosure includes a flexible printed circuit board 10 and a connection piece 20, where one end of the connection piece 20 is disposed on one side of the flexible printed circuit board 10, and the other end protrudes from the flexible printed circuit board 10.

Referring to fig. 3, the flexible printed circuit board 10 includes a substrate layer 11, a circuit layer 12 disposed on one side of the substrate layer 11, at least two copper pillars 14 disposed on the surface of the circuit layer 12, and a cover film 13 covering a part of the circuit layer 12. The circuit layer 12 includes a pad 121, and at least two copper pillars 14 are disposed on a surface of the pad 121 facing away from the substrate layer 11. At least two of the copper pillars 14 are spaced apart so that a gap 15 is formed between the two copper pillars 14.

The material of the substrate layer 11 may be one of epoxy resin (epoxy resin), polypropylene (PP), BT resin, polyphenylene Oxide (PPO), polyimide (PI), polyethylene Terephthalate (PET), and Polyethylene Naphthalate (PEN). In this embodiment, the material of the substrate layer 11 is polyimide.

It can be understood that, in the actual manufacturing process, the copper pillar 14 can be manufactured on the surface of the pad 121 by using the steps of film pressing, exposure, development, copper plating, film stripping, and the like, or the copper pillar 14 can be manufactured by using the modes of jig alignment, copper paste printing, baking and curing.

Referring to fig. 1 and 4, the connecting piece 20 includes a first surface 201 and a second surface 202 opposite to the first surface 201. The connecting piece 20 is provided with a through hole 21, the through hole 21 penetrates through the first surface 201 and the second surface 202, a part of the first surface 201 is recessed to form at least two slots 22, at least two slots 22 are communicated with the through hole 21, and at least two slots 22 are oppositely arranged on two opposite sides of the through hole 21. The two copper pillars 14 pass through the through holes 21, so that the connecting sheet 20 is disposed on the surface of the bonding pad 121 facing away from the substrate layer 11. The copper pillar 14 includes a first portion 141 and a second portion 142 connected in sequence, the first portion 141 is attached to the inner wall of the through hole 21, and the second portion 142 is bent in the slot 22.

The connecting sheet 20 may be a nickel sheet, an aluminum sheet, or a silver sheet. In this embodiment, the connecting piece 20 is a nickel piece.

The depth of the slot 22 is substantially equal to the width of the copper pillar 14, and the surface of the second portion 142 facing away from the connecting pad 20 is substantially flush with the surface of the connecting pad 20 facing away from the pad 121.

Referring to fig. 2, the number of the copper pillars 14 may be 2n (n is greater than or equal to 1, and n is a positive integer), and every two copper pillars 14 are symmetrically disposed, and the 2n copper pillars 14 are uniformly spaced around the gap 15. The flexible circuit board 10 may include m (m is greater than or equal to 1 and is a positive integer) groups of the copper pillars 14, with 2n copper pillars 14 as a group. Correspondingly, the connecting sheet 20 is provided with m through holes 21 in a penetrating manner, and each group of copper columns 14 is arranged corresponding to one through hole 21.

In this embodiment, the number of the copper pillars 14 is 4, and 4 copper pillars 14 are disposed around the circumference. The number of the through holes 21 is 2.

Referring to fig. 1 again, the cover film 13 covers the circuit layer 12 except the bonding pads 121, and fills a gap between the circuit layer 12 and the surface of the substrate layer 11. One end of the connecting sheet 20 facing the cover film 13 is approximately flush with the surface of the pad 121, and the cover film 13 is in contact with the end of the pad 121 and the end of the connecting sheet 20 so as to seal the connecting part of the connecting sheet 20 and the pad 121.

Compared with the prior art, the flexible circuit board connecting structure 100 provided in the application is provided with the copper column 14 on the surface of the flexible circuit board connecting structure 100, and the connecting sheet 20 is provided with the through hole 21 and the slot 22, the copper column 14 can penetrate through the through hole 21 through compression joint, and part of the copper column 14 can be buckled in the slot 22 after being bent, so that the flexible circuit board connecting structure 100 is fixedly connected with the connecting sheet 20. The flexible circuit board connecting structure 100 adopts a mechanical connection mode, and has high bonding strength and better reliability; solder paste is not needed, a welding process is not needed, and cost can be saved; the structure of the flexible circuit board 10 does not need to be damaged, and the surface is smooth, so that the stability and the reliability of subsequent installation and the whole structure are facilitated.

Referring to fig. 5 and fig. 6, a flexible printed circuit board connection structure 200 is further provided in the second embodiment of the present application, where the flexible printed circuit board connection structure 200 has substantially the same structure as the flexible printed circuit board connection structure 100, except that:

the connecting sheet 20 is further provided with a groove 23, and the bottom of one end of the slot 22 far away from the through hole 21 is recessed to form the groove 23. The copper pillar 14 further includes a third portion 143, and the third portion 143 and the first portion 141 are connected to opposite ends of the second portion 142, respectively. The third portion 143 is bent and then disposed in the groove 23.

Wherein the width of the groove 23 is substantially equal to the width of the copper pillar 14.

In an actual manufacturing process, referring to fig. 7, the connecting sheet 20 may be fixed on the surface of the bonding pad 121, and then a compression mold 300 is used for pressing, so that a part of the copper pillar 14 is bent, thereby obtaining the flexible circuit board connection structure 200.

Compared with the flexible circuit board connecting structure 100, the flexible circuit board connecting structure 200 has the advantages that the connecting sheet 20 is additionally provided with the groove 23, so that the bonding strength between the copper column 14 and the connecting sheet 20 after compression joint is higher, and the reliability and the stability of the whole structure are better.

The above description is only an optimized specific embodiment of the present application, but in practical application, the present application is not limited to this embodiment.

Claims

1. A flexible circuit board connecting structure is characterized by comprising a flexible circuit board and a connecting sheet arranged on one side of the flexible circuit board, wherein the flexible circuit board comprises a substrate layer, a circuit layer arranged on one side of the substrate layer and a copper column arranged on the surface of the circuit layer; the connecting piece penetrates through the through hole, a groove is formed in one surface of the connecting piece in a concave mode, the groove is communicated with the through hole, part of the copper column penetrates through the through hole and is bent, and the bent part of the copper column is arranged in the groove.

2. The flexible circuit board connecting structure according to claim 1, wherein the copper pillar includes a first portion and a second portion connected to each other, the first portion is attached to an inner wall of the through hole, the second portion is bent with respect to the first portion, and the second portion is disposed in the slot;

the surface of the second part, which faces away from the connecting sheet, is flush with the surface of the connecting sheet, which faces away from the flexible circuit board.

3. The connecting structure of the flexible circuit board according to claim 2, wherein the connecting piece is further provided with a groove, and the bottom of one end of the groove far away from the through hole is recessed to form the groove;

the copper column further comprises a third part connected to the second part, and the third part is bent and arranged in the groove.

4. The flexible wiring board connection structure according to claim 3, wherein the width of the groove is equal to the width of the third portion.

5. The flexible circuit board connecting structure according to claim 1, wherein the number of the copper pillars is 2n, n is greater than or equal to 1, and n is a positive integer;

every two have a clearance and per two between the copper post symmetry sets up, 2n the copper post is followed clearance circumference interval sets up.

6. The connecting structure of the flexible circuit board according to claim 5, wherein 2n copper pillars are taken as a group, and the flexible circuit board comprises m groups of copper pillars, wherein m is greater than or equal to 1 and is a positive integer;

7. The flexible circuit board connection structure of claim 1, wherein the circuit layer includes a bonding pad, the copper pillar is disposed on a surface of the bonding pad facing away from the substrate layer, one end of the connecting sheet is disposed on the surface of the bonding pad, and the other end protrudes out of the flexible circuit board.

8. The flexible wiring board connection structure according to claim 7, wherein the flexible wiring board further comprises a cover film covering a portion of the wiring layer other than the land.

9. The flexible wiring board connection structure according to claim 8, wherein the connection piece is flush with a surface of the bonding pad at an end facing the cover film;

10. The flexible wiring board connection structure according to claim 1, wherein the material of the base material layer is polyimide.