CN201563293U

CN201563293U - Flexible printed-circuit board

Info

Publication number: CN201563293U
Application number: CN2009202608834U
Authority: CN
Inventors: 何正清; 吴静静
Original assignee: BYD Co Ltd
Current assignee: Shenzhen Holitech Optoelectronics Co Ltd
Priority date: 2009-11-27
Filing date: 2009-11-27
Publication date: 2010-08-25
Anticipated expiration: 2019-11-27

Abstract

The utility model provides a flexible printed-circuit board, including a substrate, a first copper foil and a second copper foil distributed at both sides of the substrate, and a first cover film and a second cover film respectively covering on the first copper foil and the second copper foil, wherein the first copper foil and the second copper foil are respectively adhered to the substrate through two-sided glue, a first solder pad and a second solder pad are also respectively provided on the first copper foil and the second copper foil. Blank area and blank parts are provided on both ends of the first solder pad, and reinforce areas and reinforce parts are provided at both ends of the second solder pad. After adoption of the technical scheme of the utility model, the utility model can avoid tin stack phenomenon produced by oversize soldering tin flow quantity in the prior art, and insufficient solder phenomenon produced by undersize soldering tin flow quantity, interference to the customer terminal main board and soldering tin quantity control during employee welding, thereby ensuring the reliability of the entire die set and the actual operational of staff, so that the product yield will be greatly improved.

Description

A kind of flexible printed circuit board

Technical field

The utility model belongs to the flexible printed circuit board field, more specifically, relates to a kind of structure of flexible printed circuit board.

Background technology

Flexible printed circuit board (FPCB, Flexible Printed Circuit Board) is widely used in the various electronic products, with the PCB hardboard realization electric function that links together, so when realization is electrically connected, it is extremely important that the reliability of flexible printed circuit board welding ends just seems, the method of attachment of the welding ends pad that generally adopts is the scolding tin method of attachment at present, and it is mainly realized by manual welding and hot pressing welding.

As shown in Figure 1, be the basic structure schematic diagram of existing flexible printed circuit board.It comprises base material 1 ', be distributed in base material 1 ' both sides, and is covered in the coverlay 4 ' on the two-layer Copper Foil 3 ' respectively, and described Copper Foil 3 ' is bonding by double faced adhesive tape 2 ' and base material 1 ', and described coverlay 4 ' is also bonding by double faced adhesive tape 2 ' and Copper Foil 3 '.Described base material 1 ' mainly adopts polyimides or polyester film, and described coverlay 4 ' is mainly PI (Polyiminde).The golden finger pad 200 of this flexible printed circuit board is to form by the Copper Foil 3 ' that corrodes both sides, base material 1 ' lower end, again the coverlay 4 ' that is arranged at base material 1 ' both sides is respectively cut out with the length and width size of described golden finger pad 200 couplings and window with formation, make the golden finger pad 200 of base material 1 ' both sides expose, realization is electrically connected with other electronic devices and components.

In the prior art, the processing for two end regions 100 of described golden finger pad 200 mainly contains two kinds of processing methods, and is as follows respectively:

One; as Fig. 2 and shown in Figure 3; two end regions 10 of the double-edged golden finger pad 200 of FPCB all do not have coverlay 4 ' and Copper Foil 3 '; the mode of windowing of its coverlay 4 ' is that coverlay 4 ' and the Copper Foil 3 ' with two end regions 10 of FPCB tow sides golden finger pad 200 cuts out fully; this kind windowing method can make 200 liang of end regions 10 of FPCB golden finger pad not have the support of Copper Foil 3 ' and the protection of coverlay 4 '; and it is because too thin and soft at the exposed base material 1 ' of the portion of leaving a blank; thereby in the process of welding and assembling use, often tear; damage; even injure golden finger pad 200, cause unfavorable conditions such as FPCB short circuit.

Two, as Fig. 4 and shown in Figure 5; two end regions 10 of the double-edged golden finger pad 200 of FPCB all have Copper Foil 3 ' and coverlay 4 '; this design makes that to a certain extent FPCB has obtained protection; but two end regions 10 of golden finger pad 200 are owing to comprised base material 1 ', two-layer Copper Foil 3 ' and two-layer coverlay 4 ' simultaneously; its thickness has exceeded the thickness of golden finger pad 200, can make corner thickness too thick hard.And because when general the use, be by tin-soldering method the pad of FPCB and PCB hardboard pad to be linked together to realize electric function, the employee is when dragging the weldering scolder with flatiron, scolder melts into scolding tin and the via hole by FPCB golden finger pad 200 through the certain temperature of flatiron and flows through and flow on the PCB hardboard pad, thereby FPCB pad and pcb board pad are linked together.But because in the structure of this FPCB, because the gross thickness at golden finger pad 200 two ends is thicker than the golden finger of golden finger pad 200, in order to allow the golden finger pad 200 of FPCB golden finger pad 200 contact fully with pad on the PCB hardboard, when dragging the weldering scolder, tend to because the thickness that golden finger pad 200 two ends exceed, make the scolding tin flow increase, thereby producing solder joint differs, air spots is sliding, and pile the tin phenomenon, and then cause a hidden trouble for follow-up reliability testing, and if minimizing scolding tin flow, can cause that again golden finger pad 200 can't contact PCB hardboard pad fully, thereby produce the rosin joint phenomenon.

The utility model content

Cross when thin at the thickness that exists in the prior art, cause it to be damaged easily, even cause FPCB short circuit etc. bad when the welding disking area two ends; When the thickness at welding disking area two ends is blocked up, cause welding difficulty, and cause the shortcoming of heap tin phenomenon or rosin joint phenomenon easily, a kind of flexible printed circuit board that has improved is provided.

The technical solution of the utility model is:

A kind of flexible printed circuit board, comprise base material, be distributed in first Copper Foil and second Copper Foil of base material both sides, and be covered in first coverlay and second coverlay on first Copper Foil and second Copper Foil respectively, described first, second Copper Foil is bonding by double faced adhesive tape and base material respectively, described first Copper Foil and second Copper Foil form first pad and second pad respectively, wherein, be provided with the portion of leaving a blank, be provided with rib at the two ends of described second pad at the two ends of described first pad.

Further, the height of the described portion of leaving a blank equals the height of described first pad, and the width that the width of the described portion of leaving a blank equals flexible printed circuit board deducts the width of first pad.

Further, described rib includes three Copper Foil bonding with base material successively, and is covered in the 3rd coverlay on described the 3rd Copper Foil.

Further, described the 3rd Copper Foil and described second Copper Foil are integrally formed, and described the 3rd coverlay and described second coverlay are integrally formed.

Further, has the gap between described the 3rd coverlay and described second pad.

Further, the size in described gap is 0.5mm-0.8mm.

The beneficial effects of the utility model are:

Adopt after the technical solution of the utility model, owing to wherein be provided with the portion of leaving a blank in the two ends of the welding disking area of a side at flexible printed circuit board, opposite side is provided with rib, make the stressed damage pad of in the process of using and assembling, having avoided the welding disking area two end portions or the infringement of internal wiring, guaranteed the bulk strength at flexible printed circuit board welding disking area two ends, in addition, owing to respectively be provided with the portion of leaving a blank and rib in the both sides of flexible printed circuit board, make on the thickness direction of this flexible printed circuit board, the thickness difference at welding disking area and welding disking area two ends is very little, too small and the rosin joint phenomenon that produces of the heap tin phenomenon of the excessive generation of scolding tin flow that exists in the prior art and scolding tin flow be can avoid thus, thereby the reliability and the actual operability of entire module guaranteed.

Description of drawings

Fig. 1 is the basic structure schematic diagram of existing flexible printed circuit board;

Fig. 2 is the structural representation that the two ends of flexible printed circuit board both sides welding disking area in the prior art all do not have Copper Foil and coverlay;

Fig. 3 is along the generalized section of A-A direction among Fig. 2;

Fig. 4 is the structural representation that the two ends of flexible printed circuit board both sides welding disking area in the prior art are provided with Copper Foil and coverlay;

Fig. 5 is along the generalized section of B-B direction among Fig. 4;

Fig. 6 is the Facad structure schematic diagram of a kind of embodiment of flexible printed circuit board of providing of the utility model;

Fig. 7 is the reverse side structural representation of a kind of embodiment of flexible printed circuit board of providing of the utility model;

Fig. 8 is along the generalized section of C-C direction among Fig. 6;

Fig. 9 is along the generalized section of D-D direction among Fig. 6.

Embodiment

Clearer for technical problem, technical scheme and beneficial effect that the utility model is solved, below in conjunction with drawings and Examples, the utility model is further elaborated.Should be appreciated that specific embodiment described herein only in order to explanation the utility model, and be not used in qualification the utility model.

Extremely shown in Figure 9 as Fig. 6, the utility model provides a kind of flexible printed circuit board, comprise base material 1, be distributed in first Copper Foil 31 and second Copper Foil 32 of base material 1 both sides, and be covered in first coverlay 41 and second coverlay 42 on first Copper Foil 31 and second Copper Foil 32 respectively, described first, second Copper Foil 32 is bonding by double faced adhesive tape and base material 1 respectively, described first Copper Foil 31 and second Copper Foil 32 form first pad 400 and second pad 401 respectively, wherein, be provided with the portion of leaving a blank 300 at the two ends of described first pad 400, be provided with rib 301 at the two ends of described second pad 401.

Above-mentioned first pad 400 and second pad 401 of on described first Copper Foil 31 and second Copper Foil 32, forming respectively, more specifically, be to form first pad 400 and second pad 401 by surface treatment in the lower end of described first Copper Foil 31 and second Copper Foil 32, this part technology contents is that those skilled in the art are known, does not too much give unnecessary details here.

A kind of embodiment that provides according to the utility model with reference to Fig. 6, is the Facad structure schematic diagram of a kind of embodiment of flexible printed circuit board of providing of the utility model.And with reference to Fig. 8 and Fig. 9, Fig. 8 be among Fig. 6 along the generalized section of C-C direction, Fig. 9 is along the generalized section of D-D direction among Fig. 6.As can be seen from the figure, be provided with the portion of leaving a blank 300 at the two ends of described first pad 400, what the described portion 300 of leaving a blank was exposed to the outside is base material 1, promptly, by cutting out or additive method will place the Copper Foil and the coverlay of described base material 1 upside to cut out, only remaining base material 1 exposes.L1 represents the length of first pad 400, and L2 represents the length of the window length or the flexible printed circuit board of coverlay, so this positive coverlay is to window fully, does not reserve the protection of Copper Foil and coverlay at the two ends of described first pad 400.

Further, described height of leaving a blank portion 300 equals the height of described first pad 400, and the width that described width of leaving a blank portion 300 equals flexible printed circuit board deducts the width of first pad 400.

With reference to Fig. 7, be the reverse side structural representation of a kind of embodiment of flexible printed circuit board of providing of the utility model.Described rib 301 includes three Copper Foil 33 bonding with base material 1 successively, and is covered in the 3rd coverlay 43 on described the 3rd Copper Foil 33.

Further, described the 3rd Copper Foil 33 is integrally formed with described second Copper Foil 32, and described the 3rd coverlay 43 is integrally formed with described second coverlay 42.

Further, has gap T between described the 3rd coverlay 43 and described second pad 401.Under the preferable case, the size of described gap T is 0.5mm-0.8mm.According to an embodiment of the present utility model, can learn in conjunction with Fig. 6, described L3=T+L1+T, wherein, described T is 0.5mm, and described L3 represents the length of windowing of reverse side second coverlay 42, and L1 represents the length of second pad 401.This design is under the 3rd coverlay 43 situations that kept second pad, 401 both sides, also controlled the opening size of second coverlay 42, avoid because of the opening of coverlay too little, operating personnel are carrying out causing that tolerance is very big when hand pastes operation, cause first coverlay 41 directly is affixed on second pad 401, thereby cause bad order, and cause the problem that causes rosin joint when welding easily.

Adopt after the technical solution of the utility model, owing to wherein be provided with the portion of leaving a blank 300 in the two ends of the welding disking area of a side at flexible printed circuit board, opposite side is provided with rib 301, make the stressed damage pad of in the process of using and assembling, having avoided the welding disking area two end portions or the infringement of internal wiring, guaranteed the bulk strength at flexible printed circuit board welding disking area two ends, in addition, owing to respectively be provided with portion of leaving a blank 300 and rib 301 in the both sides of flexible printed circuit board, make on the thickness direction of this flexible printed circuit board, the thickness difference at welding disking area and welding disking area two ends is very little, too small and the rosin joint phenomenon that produces of the heap tin phenomenon of the excessive generation of scolding tin flow that exists in the prior art and scolding tin flow be can avoid thus, thereby the reliability and the actual operability of entire module guaranteed.

The above only is preferred embodiment of the present utility model; not in order to restriction the utility model; all any modifications of within spirit of the present utility model and principle, being done, be equal to and replace and improvement etc., all should be included within the protection range of the present utility model.

Claims

1. flexible printed circuit board, comprise base material, be distributed in first Copper Foil and second Copper Foil of base material both sides, and be covered in first coverlay and second coverlay on first Copper Foil and second Copper Foil respectively, described first, second Copper Foil is bonding by double faced adhesive tape and base material respectively, described first Copper Foil and second Copper Foil form first pad and second pad respectively, it is characterized in that, two ends at described first pad are provided with the portion of leaving a blank, and are provided with rib at the two ends of described second pad.

2. flexible printed circuit board as claimed in claim 1 is characterized in that the height of the described portion of leaving a blank equals the height of described first pad, and the width that the width of the described portion of leaving a blank equals flexible printed circuit board deducts the width of first pad.

3. flexible printed circuit board as claimed in claim 1 is characterized in that, described rib includes three Copper Foil bonding with base material successively, and is covered in the 3rd coverlay on described the 3rd Copper Foil.

4. flexible printed circuit board as claimed in claim 3 is characterized in that, described the 3rd Copper Foil and described second Copper Foil are integrally formed, and described the 3rd coverlay and described second coverlay are integrally formed.

5. flexible printed circuit board as claimed in claim 4 is characterized in that, has the gap between described the 3rd coverlay and described second pad.

6. flexible printed circuit board as claimed in claim 5 is characterized in that, the size in described gap is 0.5mm-0.8mm.