CN211457539U

CN211457539U - Multilayer interconnection FPC with lead tin via hole fast

Info

Publication number: CN211457539U
Application number: CN202020027504.3U
Authority: CN
Inventors: 向勇; 胡高强; 覃逸龙; 曾产; 税晓明
Original assignee: ZHUHAI TOPSUN ELECTRONIC TECHNOLOGY CO LTD; University of Electronic Science and Technology of China
Current assignee: Zhuhai Zhongjing Yuansheng Electronic Technology Co ltd; University of Electronic Science and Technology of China
Priority date: 2020-01-07
Filing date: 2020-01-07
Publication date: 2020-09-08
Anticipated expiration: 2030-01-07

Abstract

The utility model provides a simple structure, material utilization rate are high, and can fuse into enough soldering tin fast when the welding, the stable performance have lead the multilayer interconnection FPC of tin via hole fast. The utility model comprises a main FPC and an auxiliary FPC, wherein the main FPC is provided with a main output area and a main input area, and the auxiliary FPC is provided with an auxiliary output area and an auxiliary input area; a main output bonding pad is arranged in the main output area, a main input bonding pad is arranged in the main input area, an auxiliary output bonding pad is arranged in the auxiliary output area, an auxiliary input bonding pad is arranged in the auxiliary input area, and tin conducting through holes are formed in the auxiliary output bonding pad and the auxiliary input bonding pad; the main output bonding pad and the main input bonding pad are both provided with at least one vent hole; a metal layer is plated in the tin-conducting through hole, and the metal layer of the tin-conducting through hole on the auxiliary input pad is connected with the auxiliary input pad; and soldering tin is melted into the tin guide through hole, and the main input bonding pad is communicated with the auxiliary output bonding pad through the soldering tin. The utility model discloses be applied to the technical field of FPC production.

Description

Multilayer interconnection FPC with lead tin via hole fast

Technical Field

The utility model relates to a technical field of flexible circuit board, in particular to multilayer interconnection flexible circuit board (FPC) with lead tin via hole fast.

Background

Multilayer FPC boards have multiple wiring layers with an insulating layer between two adjacent wiring layers, and multilayer circuit boards generally have at least three conductive layers, two of which are on the outer surface and the remaining one incorporated in an insulating board, and the electrical connection between them is usually made by plated through holes in the cross section of the circuit board. For some multi-layer FPCs, the number of the wires in a certain conductive layer is small, so that the practical use area of the layer is small, the material utilization rate is low, and great material waste is caused. Therefore, a multilayer interconnection FPC consisting of a main FPC large board and a plurality of auxiliary FPC small boards is developed, and the quality of welding between the main FPC and the auxiliary FPC can directly influence the quality of a product. Because the area design of the circuit board is limited, the sizes of the bonding pads of the main FPC and the auxiliary FPC are limited, so that the good contact between the main FPC and the auxiliary FPC is ensured, enough soldering tin amount between the bonding pads of the main FPC and the auxiliary FPC is ensured under the condition of limited bonding pad area, but the problem that how to quickly fuse enough soldering tin between the bonding pads of the main FPC and the auxiliary FPC cannot be well solved in the prior art.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that overcome prior art not enough, provide a simple structure, material utilization rate is high, and can fuse into enough soldering tin fast when the welding, stable performance has the multilayer interconnection FPC of leading the tin via hole fast.

The utility model adopts the technical proposal that: the utility model comprises a main FPC and an auxiliary FPC, wherein the main FPC is provided with a main output area and a main input area, and the auxiliary FPC is provided with an auxiliary output area and an auxiliary input area; a plurality of main output bonding pads connected with the main FPC circuit are arranged in the main output area, a plurality of main input bonding pads connected with the main FPC circuit are arranged in the main input area, a plurality of auxiliary output bonding pads connected with the auxiliary FPC circuit and corresponding to the main input bonding pads one by one are arranged in the auxiliary output area, a plurality of auxiliary input bonding pads connected with the auxiliary FPC circuit and corresponding to the main output bonding pads one by one are arranged in the auxiliary input area, tin conducting through holes are arranged on the auxiliary output bonding pads and the auxiliary input bonding pads, and the tin conducting through holes conduct the upper surface and the lower surface of the auxiliary FPC; the main output bonding pad and the main input bonding pad are both provided with at least one exhaust hole, and the exhaust holes are communicated with the upper surface and the lower surface of the main FPC; a metal layer is plated in the tin-conducting through hole, the metal layer of the tin-conducting through hole on the auxiliary output bonding pad is connected with the auxiliary output bonding pad, and the metal layer of the tin-conducting through hole on the auxiliary input bonding pad is connected with the auxiliary input bonding pad; lead the tin and pass through the downthehole solder tin that fuses of hole, main output pad with assist the input pad and pass through the solder tin intercommunication, lead the tin and pass through the downthehole solder tin that fuses of hole, main input pad with assist the output pad and pass through the solder tin intercommunication.

Further, the exhaust hole is formed in an eccentric position of the main output pad and the main input pad.

Further, lead the tin via hole and be located assist on the output pad with assist the central point of input pad and put, lead the aperture of tin via hole and establish to 100um to 300um, assist on the output pad with assist the input pad and all be the annular, annular ring width is greater than 100 um.

Furthermore, the edge of the tin conducting through hole is provided with a plurality of notches.

Furthermore, a plurality of main output test pads are uniformly arranged at the edge of the main output area, and auxiliary input test pads corresponding to the main output test pads one to one are uniformly arranged at the edge of the auxiliary input area; the utility model discloses a tin via hole is led to the last main output test pad that is equipped with of main FPC, be equipped with a plurality of respectively with a plurality of main output test circuit that main output test pad is connected, be equipped with a plurality of respectively on assisting FPC with a plurality of assist the input test circuit of assisting that input test pad is connected, main output test circuit with main FPC circuit is not connected, assist input test circuit with assist FPC circuit and not connect, on the main output test pad with assist also being equipped with on the input test pad lead the tin via hole, main output test pad with assist the welding of input test pad and be in the same place.

Furthermore, a plurality of main input test pads are uniformly arranged at the edge of the main input area, and auxiliary output test pads corresponding to the main input test pads one to one are uniformly arranged at the edge of the auxiliary output area; the utility model discloses a tin via hole is led to the main input test pad, the main FPC is last to be equipped with a plurality of respectively with a plurality of main input test circuit that the main input test pad is connected, be equipped with a plurality of on assisting FPC respectively with a plurality of assist the output test circuit that the output test pad is connected, main input test circuit with main FPC circuit is not connected, assist output test circuit with assist FPC circuit and not connect, on the main input test pad with assist also to be equipped with on the output test pad lead the tin via hole, main input test pad with assist the welding of output test pad and be in the same place.

Further, the tin-conducting through hole is an elliptical hole or a cross-shaped hole.

Further, tin or gold is plated in the tin conducting through holes, the main FPC is a single-layer or multi-layer FPC, and the auxiliary FPC is a single-layer or multi-layer FPC; and a double-sided adhesive tape is arranged between the main FPC and the auxiliary FPC.

The utility model has the advantages that: because the utility model adopts the design of the fast tin guiding through hole, the auxiliary output bonding pad and the auxiliary input bonding pad are both provided with the tin guiding through hole, and the tin guiding through hole is communicated with the upper surface and the lower surface of the auxiliary FPC; the main output bonding pad and the main input bonding pad are both provided with at least one exhaust hole, and the exhaust holes are communicated with the upper surface and the lower surface of the main FPC; the auxiliary input bonding pad is welded on the main output bonding pad, and the auxiliary output bonding pad is welded on the main input bonding pad; a metal layer is plated in the tin-conducting through hole, the metal layer of the tin-conducting through hole on the auxiliary output bonding pad is connected with the auxiliary output bonding pad, and the metal layer of the tin-conducting through hole on the auxiliary input bonding pad is connected with the auxiliary input bonding pad; lead tin and penetrate soldering tin in the hole, main input pad with assist the output pad and pass through the soldering tin intercommunication, lead tin and penetrate soldering tin in the hole, main output pad with assist the input pad and pass through the soldering tin intercommunication, so, the utility model discloses simple structure avoids simple circuit to use the material of whole page, for traditional multilayer FPC, the utility model discloses a material utilization is high, and can discharge the air through the exhaust hole when the welding, effectively prevents the rosin joint, can also accelerate soldering tin inflow speed, and the soldering tin volume is sufficient, and welding performance is stable, and the product quality is high.

Drawings

Fig. 1 is a schematic structural view of the tin-conductive via 11;

fig. 2 is a schematic structural diagram of the tin-conductive via 11;

fig. 3 is a schematic structural view of the main FPC;

fig. 4 is a schematic view of the structure of the auxiliary FPC;

FIG. 5 is an enlarged view at A of FIG. 2;

FIG. 6 is a schematic structural view of the multi-layer interconnected FPC of the present invention;

fig. 7 is a schematic structural view of the main FPC1 and the auxiliary FPC2 when they are not yet soldered;

fig. 8 is a schematic view of the structure when the main FPC1 and the auxiliary FPC2 have been soldered.

Detailed Description

As shown in fig. 1 to 6, in the present embodiment, the multi-layer interconnection FPC with the fast tin-conducting via hole includes a main FPC1 and an auxiliary FPC2, wherein the main FPC1 is provided with a main output region 3 and a main input region 4, and the auxiliary FPC2 is provided with an auxiliary output region 5 and an auxiliary input region 6; a plurality of main output pads 7 which are in circuit connection with the main FPC1 are arranged in the main output area 3, a plurality of main input pads 8 which are in circuit connection with the main FPC1 are arranged in the main input area 4, a plurality of auxiliary output pads 9 which are in circuit connection with the auxiliary FPC2 and are in one-to-one correspondence with the main input pads 8 are arranged in the auxiliary output area 5, a plurality of auxiliary input pads 10 which are in circuit connection with the auxiliary FPC2 and are in one-to-one correspondence with the main output pads 7 are arranged in the auxiliary input area 6, tin conducting through holes 11 are formed in the auxiliary output pads 9 and the auxiliary input pads 10, and the tin conducting through holes 11 conduct the upper surface and the lower surface of the auxiliary FPC 2; at least one vent hole 19 is formed in each of the main output pad 7 and the main input pad 8, and the vent holes 19 conduct the upper surface and the lower surface of the main FPC 1; the auxiliary input pad 10 is welded on the main output pad 7, and the auxiliary output pad 9 is welded on the main input pad 8; a metal layer 16 is plated in the tin-conducting through hole 11, the metal layer 16 of the tin-conducting through hole 11 on the auxiliary output pad 9 is connected with the auxiliary output pad 9, and the metal layer 16 of the tin-conducting through hole 11 on the auxiliary input pad 10 is connected with the auxiliary input pad 10; lead and weld tin 17 in the tin via hole 11, lead and weld tin (17) in the tin via hole 11, main output pad 7 with assist input pad 10 and pass through soldering tin 17 intercommunication, main input pad 8 with assist output pad 9 and pass through soldering tin 17 intercommunication. The utility model discloses a reflow soldering's welding mode, reflow soldering make tin melt from the surface to the inside hot-blast messenger, and the surface melts the inside air of back and passes through exhaust hole 19 is discharged to can not produce the rosin joint, the design size in exhaust hole 19's aperture is 0.05-0.2mm, best 0.1 mm.

The utility model discloses simple structure avoids simple circuit to use the material of whole page, for traditional multilayer FPC, the utility model discloses a material utilization rate is high, and can effectively prevent the rosin joint through exhaust hole with air escape when the welding, can also accelerate soldering tin inflow speed, and the soldering tin volume is sufficient, and welding performance is stable, and the product quality is high.

In this embodiment, the vent hole 19 is provided at an eccentric position of the main output pad 7 and the main input pad 8.

In this embodiment, lead tin via hole 11 and be located assist on the output pad 9 with assist the central point of input pad 10 and put, lead the aperture of tin via hole 11 and be 100um to 300um, assist on the output pad 9 with assist input pad 10 and all be the annular, annular ring width is greater than 100 um. In this embodiment, in order to compress the structure and leave a space for customer wiring, the aperture of the tin via hole 11 can only be designed to be between 100-300 um, most of the tin paste is only 150um, the tin paste needs to flow through the tin via hole 11, but the diameter of the finest tin particle is 25-30 um at present, according to the size of the tin particle, the optimum size of the tin via hole 11 should be designed to be more than or equal to 10 times of the tin particle, and when the tin paste is printed, more than 10 tin particles pass through at the same time, so that the soldering can be ensured.

In this embodiment, the edge of the tin-conducting via hole 11 is provided with a plurality of notches 20, so that the tin-passing area is increased, and good soldering is ensured.

In this embodiment, a plurality of the primary output pads 7 are uniformly or non-uniformly distributed in the primary output region 3. Since the plurality of main output bonding pads 7 are not linearly distributed, more main output bonding pads 7 can be arranged in the main output area 3, and more requirements are met.

In this embodiment, a number of the primary input pads 8 are evenly or unevenly distributed within the primary input area 4. Since the main input pads 8 are not linearly distributed, more main input pads 8 can be arranged in the main input area 4, and more requirements are met.

In this embodiment, a plurality of main output test pads 12 are uniformly arranged at the edge of the main output area 3, and auxiliary input test pads 13 corresponding to the main output test pads 12 one to one are uniformly arranged at the edge of the auxiliary input area 6; be equipped with on the main FPC1 a plurality of respectively with a plurality of the main output test circuit that main output test pad 12 is connected, be equipped with on the assistance FPC2 a plurality of respectively with a plurality of assist the input test circuit of assisting that input test pad 13 is connected, main output test circuit with main FPC1 circuit is disconnected, assist the input test circuit with assist FPC2 circuit and disconnect from each other, assist the input test circuit with assist FPC2 circuit and disconnect from each other, main output test pad 12 on with assist also to be equipped with on the input test pad 13 lead tin via hole 11, main output test pad 12) with assist the welding of input test pad 13 and be in the same place.

In this embodiment, a plurality of main input test pads 14 are uniformly arranged at the edge of the main input area 4, and auxiliary output test pads 15 corresponding to the main input test pads 14 one to one are uniformly arranged at the edge of the auxiliary output area 5; be equipped with on the main FPC1 a plurality of respectively with a plurality of the main input test circuit that main input test pad 14 is connected, be equipped with on the assistance FPC2 a plurality of respectively with a plurality of assist the supplementary output test circuit that output test pad 15 is connected, main input test circuit with main FPC1 circuit is disconnected, assist output test circuit with assist FPC2 circuit and do not throw out, assist output test circuit with assist FPC2 circuit and do not throw out, main input test pad 14 on with assist also to be equipped with on the output test pad 15 lead tin via hole 11, main input test pad 14 with assist the welding of output test pad 15 and be in the same place.

In this embodiment, the tin-conducting via 11 is an elliptical hole or a cross-shaped hole. Lead tin via hole 11 and vacate more tin channels through establishing to oval hole or cross shape hole, the pad that enables to have certain area for soldering tin can smoothly flow in lead in the tin via hole 11, can effectively avoid rosin joint, welding inadequately and other bad phenomena.

As shown in fig. 7 and 8, in the present embodiment, both the main FPC1 and the auxiliary FPC2 are double-layer FPCs. Be provided with double faced adhesive tape 18 between main FPC1 and the supplementary FPC2, double faced adhesive tape 18 is used for main FPC1 with supplementary FPC2 is fixed in advance, ensures that follow-up welding has higher precision, guarantees the yields. In this embodiment, the main FPC1 and the auxiliary FPC2 each include a base material PI, copper foils are disposed on both surfaces of the base material PI, a coverlay film or green oil is disposed on the surfaces of the copper foils, and the two copper foils of the auxiliary FPC2 are electrically connected by plating gold in the tin conductive vias 11. The main output pad 7 and the main input pad 8 are both connected with the upper copper foil of the main FPC 1. The main FPC1 and the auxiliary FPC2 can achieve the same function as a four-layer FPC board after welding, and a local four-layer FPC structure is formed. For traditional multilayer FPC, the utility model discloses a material utilization is high, and the performance is more stable.

The utility model discloses be applied to flexible circuit board's technical field.

While the embodiments of the present invention have been described in terms of practical embodiments, they are not intended to limit the scope of the invention, and modifications of the embodiments and combinations with other embodiments will be apparent to those skilled in the art in light of the present description.

Claims

1. A multilayer interconnected FPC with fast tin-conducting through holes comprises a main FPC (1) and an auxiliary FPC (2), wherein a main output area (3) and a main input area (4) are arranged on the main FPC (1), and an auxiliary output area (5) and an auxiliary input area (6) are arranged on the auxiliary FPC (2); be provided with in main output area (3) a plurality of with main output pad (7) of main FPC (1) circuit connection, be provided with in main input area (4) a plurality of with main input pad (8) of main FPC (1) circuit connection, be provided with in the assistance output area (5) a plurality of with assist FPC (2) circuit connection and with the assistance output pad (9) of main input pad (8) one-to-one, be provided with in the assistance input area (6) a plurality of with assist FPC (2) circuit connection and with the assistance input pad (10) of main output pad (7) one-to-one, its characterized in that: tin conducting through holes (11) are formed in the auxiliary output bonding pad (9) and the auxiliary input bonding pad (10), and the tin conducting through holes (11) conduct the upper surface and the lower surface of the auxiliary FPC (2); at least one exhaust hole (19) is formed in each of the main output bonding pad (7) and the main input bonding pad (8), and the exhaust holes (19) conduct the upper surface and the lower surface of the main FPC (1); a metal layer (16) is plated in the tin-conducting through hole (11), the metal layer (16) of the tin-conducting through hole (11) on the auxiliary output bonding pad (9) is connected with the auxiliary output bonding pad (9), and the metal layer (16) of the tin-conducting through hole (11) on the auxiliary input bonding pad (10) is connected with the auxiliary input bonding pad (10); lead and fuse tin (17) in tin via hole (11), main output pad (7) with assist input pad (10) and pass through soldering tin (17) intercommunication, main input pad (8) with assist output pad (9) and pass through soldering tin (17) intercommunication.

2. The multilayer interconnected FPC with fast tin-conducting via holes as claimed in claim 1, wherein: the exhaust hole (19) is arranged at the eccentric position of the main output bonding pad (7) and the main input bonding pad (8).

3. The multilayer interconnected FPC with fast tin-conducting via holes as claimed in claim 1, wherein: lead tin via hole (11) and be located assist on output pad (9) with assist the central point of input pad (10) and put, the aperture that leads tin via hole (11) is 100um to 300um, assist on output pad (9) with assist input pad (10) and all be the annular, annular ring width is greater than 100 um.

4. The multi-layer interconnection FPC with the fast tin-conducting via hole as claimed in claim 3, wherein: the edge of the tin-conducting through hole (11) is provided with a plurality of notches (20).

5. The multilayer interconnected FPC with fast tin conducting vias as claimed in claim 4, wherein: the tin-conducting through hole (11) is an elliptical hole or a cross-shaped hole.

6. The multilayer interconnected FPC with fast tin-conducting via holes as claimed in claim 1, wherein: a plurality of main output test pads (12) are uniformly arranged at the edge of the main output area (3), and auxiliary input test pads (13) which are in one-to-one correspondence with the main output test pads (12) are uniformly arranged at the edge of the auxiliary input area (6); be equipped with on main FPC (1) a plurality of respectively with a plurality of main output test circuit that main output test pad (12) is connected, be equipped with on assisting FPC (2) a plurality of respectively with a plurality of assist the input test circuit of assisting that input test pad (13) are connected, main output test circuit with main FPC (1) circuit is disconnected, assist input test circuit with assist FPC (2) circuit and not connect, main output test pad (12) go up with assist and also be equipped with on input test pad (13) lead tin via hole (11), main output test pad (12) with assist input test pad (13) welding together.

7. The multilayer interconnected FPC with fast tin-conducting via holes as claimed in claim 1, wherein: a plurality of main input test pads (14) are uniformly arranged at the edge of the main input area (4), and auxiliary output test pads (15) which are in one-to-one correspondence with the main input test pads (14) are uniformly arranged at the edge of the auxiliary output area (5); be equipped with on main FPC (1) a plurality of respectively with a plurality of main input test circuit that main input test pad (14) is connected, be equipped with on assisting FPC (2) a plurality of respectively with a plurality of assist output test circuit that output test pad (15) are connected, main input test circuit with main FPC (1) circuit is disconnected, assist output test circuit with assist FPC (2) circuit and do not throw out, main input test pad (14) go up with assist and also be equipped with on output test pad (15) lead tin via hole (11), main input test pad (14) with assist output test pad (15) welding together.

8. The multilayer interconnected FPC with fast tin-conducting via holes as claimed in claim 1, wherein: the tin conducting through holes (11) are plated with tin or gold; the main FPC (1) is a single-layer or multi-layer FPC, and the auxiliary FPC (2) is a single-layer or multi-layer FPC; a double-sided adhesive tape (18) is arranged between the main FPC (1) and the auxiliary FPC (2).