CN214101903U

CN214101903U - Connection structure of high-end rigid-flex printed circuit board

Info

Publication number: CN214101903U
Application number: CN202120147055.0U
Authority: CN
Inventors: 易君君
Original assignee: Shenzhen Chenghe Hongye Technology Co ltd
Current assignee: Shenzhen Chenghe Hongye Technology Co ltd
Priority date: 2021-01-20
Filing date: 2021-01-20
Publication date: 2021-08-31
Anticipated expiration: 2031-01-20

Abstract

The utility model discloses a connection structure of high-end rigid-flex printed circuit board, including crimping head, pressfitting pedestal, flexible board base material and the rigid board base material that can provide temperature and pressure, the first teflon of lower extreme fixedly connected with of crimping head fills up, the upper end fixedly connected with second teflon of pressfitting pedestal fills up, be provided with flexible board golden finger end and rigid board golden finger end on flexible board base material and the rigid board base material respectively, rigid board golden finger end is located the upper end of second teflon pad, the upper end fixed paste of rigid board golden finger end has the anisotropic conductive adhesive, the upper end of anisotropic conductive adhesive is provided with flexible board golden finger end. The utility model discloses when using, solved the rigid-flex printed circuit board's rigid plate and the rigid-flex part interconnect's of the low width golden finger of flexbile plate problem, it is very convenient to use.

Description

Connection structure of high-end rigid-flex printed circuit board

Technical Field

The utility model relates to a printed circuit board processing equipment technical field specifically is a high-end rigid-flex printed circuit board's connection structure.

Background

At present, the production amount of Chinese printed circuit boards accounts for more than 65 percent of the whole world, but the market share of the produced high-end printed circuit boards is less than 25 percent. With the accelerated layout of the global communication industry on 5G and 6G, the demand of high-end rigid-flexible printed circuit boards is greatly increased.

The typical flex-rigid printed circuit board uses one or more polyimide copper clad plates as a flexible part, a required circuit is manufactured on the copper foil layer, then an FR4 and copper foil are pressed into a multilayer circuit board on the outer layer, and interlayer conduction is realized by a method of copper deposition and electroplating after drilling. However, due to the mixed use of multiple materials and multiple manufacturing steps, the processing time is long, the manufacturing cost is high, and due to the difference between the thermal expansion Coefficient (CTE) and the glass transition Temperature (TG) of FR4 and polyimide materials, the problems of poor interconnection of inner layers (ICD), hole thickness, separation of inner layer hole walls, low weather resistance level and the like are easily caused, and the reliability of products is seriously affected.

In order to solve the problems, for a rigid-flexible printed circuit board with high reliability requirement, a rigid board and a flexible board need to be separately designed and manufactured and then are communicated with each other in a mode of mutually arranging connecting positions, and the main connecting method adopted in the industry at present has the following defects:

the first method is to weld a ZIF plug connector on a rigid board and then insert a reinforcing gold finger designed for FPC into the ZIF plug connector on the rigid board. However, the PIN gaps of the connectors are all over 0.50mm, and the volume of the rigid-flexible printed board is increased due to the large volume of the ZIF plug-in connector, so that the requirements of 'light, thin and small' of a high-end rigid-flexible printed board cannot be met.

In the two methods, the rigid plate and the flexible plate are connected by welding the connecting positions of the rigid plate and the flexible plate, the rigid plate is designed into a golden finger mode, the flexible plate is designed into a corresponding double-sided golden finger + tin through hole mode, and the connecting positions are welded by manual or automatic equipment. In order to guarantee the welding effect, the minimum width and length of the golden finger is 0.60 multiplied by 3.0mm, the design requirement of the number of the golden fingers of the FPC is 50 feet, the total welding position of the golden finger exceeds 60.0 multiplied by 3.0mm, the connecting position occupies the large area, the design requirements of light weight, thinness and small size of the high-end rigid-flex printed circuit board cannot be met, soldering flux residue and tin bead and tin slag can be caused in the welding process, and certain hidden danger is brought to the quality of the rigid-flex printed circuit board.

At present, in 5G and 6G high-end rigid-flex printed circuit boards in part of communication industries, rigid plates and flexible plates which are separately manufactured need to be interconnected, the minimum design requirement of the width of a single golden finger at a connection position is 0.050mm (50 μm) and extra welding area cannot be provided, and the traditional connection method can only connect the rigid plate and the flexible plate with the width of the single golden finger being more than 0.50mm, so that the design of a connection structure of the rigid-flex printed circuit board is not reasonable enough, and therefore a connection structure of the rigid-flex printed circuit board needs to be provided.

SUMMERY OF THE UTILITY MODEL

The utility model provides a to prior art not enough, the utility model provides a novel rigid-flex printed circuit board's connection method has solved the rigid-flex part interconnect's of low width golden finger problem.

In order to achieve the above object, the utility model provides a following technical scheme: the utility model provides a connection structure of high-end rigid-flex printed circuit board, includes crimping head, pressfitting pedestal, flexible board base material and the rigid board base material that can provide temperature and pressure, the first teflon of lower extreme fixedly connected with of crimping head fills up, the upper end fixedly connected with second teflon of pressfitting pedestal fills up, be provided with flexible board golden finger end and rigid board golden finger end on flexible board base material and the rigid board base material respectively, rigid board golden finger end is located the upper end of second teflon pad, the upper end fixed paste of rigid board golden finger end has the anisotropic conductive adhesive, the upper end of anisotropic conductive adhesive is provided with flexible board golden finger end.

Preferably, the temperature range provided by the crimping head is set to 100-200 ℃, and the pressure range provided by the crimping head is set to 0.03-0.2 MPa.

Preferably, the lower end of the flexible board base material is fixedly provided with a flexible board golden finger, and the upper end of the rigid board base material is fixedly provided with a rigid board golden finger.

Preferably, the flexible sheet metal fingers and the rigid sheet metal fingers are arranged in an aligned mode, multiple groups of flexible sheet metal fingers and multiple groups of rigid sheet metal fingers are arranged, and equidistant gaps are formed between the multiple groups of flexible sheet metal fingers and the multiple groups of rigid sheet metal fingers.

Preferably, the anisotropic conductive paste includes first conductive particles and second conductive particles, and the second conductive particles are the first conductive particles after being pressed by the pressing head.

Preferably, the first conductive particles are located in equidistant gaps arranged between the groups of the flexible sheet metal fingers and the rigid sheet metal fingers, and the second conductive particles are located between the flexible sheet metal fingers and the rigid sheet metal fingers which are arranged in an aligned manner.

Compared with the prior art, the beneficial effects of the utility model are that:

1. the utility model discloses an adopt new material anisotropic conductive adhesive, utilize it to receive certain pressure and temperature condition in the longitudinal direction, the first conductive particle of its inside takes place to explode after being extruded and accomplishes the electric conduction and become the second conductive particle, and the first conductive particle in horizontal plane and the not golden finger space area of insufficient pressure still has the high impedance characteristic, solve the problem that the rigid-flex part of the rigid plate of high-end rigid-flex combination printed circuit board and the low width golden finger of flexbile plate interconnects;

2. the utility model discloses it is high to have production efficiency, can press in the short time, and the reliability after that is high, and heat resistance is good, still can keep good reliability after that through the reflow soldering stove, and it is very convenient to use.

Drawings

FIG. 1 is a schematic view of the anisotropic conductive adhesive of the present invention attached to a rigid plate gold finger;

fig. 2 is a schematic structural view of the present invention in which the golden fingers of the rigid board and the flexible board are pressed together by anisotropic conductive adhesive;

fig. 3 is the utility model discloses the structure schematic diagram that the cross-section of the rigid-flex pressfitting position of rigid-flex printed board was enlarged.

In the figure: 1. a crimping head; 2. a first teflon pad; 3. a flexible sheet metal finger tip; 4. anisotropic conductive adhesive; 5. a rigid sheet metal finger tip; 6. a second Teflon pad; 7. pressing the pedestal; 8. a flexible board substrate; 9. a flexible sheet metal finger; 10. first conductive particles; 11. a rigid plate substrate; 12. a rigid sheet metal finger; 13. second conductive particles.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Referring to fig. 1-3, the present invention provides a technical solution:

the utility model provides a connection structure of high-end rigid-flex printed circuit board, including the crimping head 1 that can provide temperature and pressure, pressfitting pedestal 7, flexible board base material 8 and rigid board base material 11, the lower extreme fixedly connected with first teflon pad 2 of crimping head 1, the upper end fixedly connected with second teflon pad 6 of pressfitting pedestal 7, be provided with flexible board golden finger end 3 and rigid board golden finger end 5 on flexible board base material 8 and the rigid board base material 11 respectively, rigid board golden finger end 5 is located the upper end of second teflon pad 6, the upper end fixed paste of rigid board golden finger end 5 has anisotropic conductive adhesive 4, the upper end of anisotropic conductive adhesive 4 is provided with flexible board golden finger end 3.

The temperature range provided by the crimping head 1 is set to be 100-200 ℃, and the pressure range provided by the crimping head 1 is set to be 0.03-0.2 MPa.

The lower end of the flexible plate base material 8 is fixedly provided with a flexible plate golden finger 9, and the upper end of the rigid plate base material 11 is fixedly provided with a rigid plate golden finger 12.

The flexible metal fingers 9 and the rigid metal fingers 12 are arranged in an aligned manner, a plurality of groups of flexible metal fingers 9 and rigid metal fingers 12 are arranged, and equidistant gaps are arranged between the groups of flexible metal fingers 9 and rigid metal fingers 12.

The anisotropic conductive paste 4 includes first conductive particles 10 and second conductive particles 13, and the second conductive particles 13 are the first conductive particles 10 that have been crimped by the crimp head 1.

The first conductive particles 10 are located in equidistant gaps provided between the sets of flexible sheet metal fingers 9 and rigid sheet metal fingers 12, and the second conductive particles 13 are located between the flexible sheet metal fingers 9 and the rigid sheet metal fingers 12 in alignment.

As shown in figure 1, a finger end 5 of a rigid metal plate which is processed cleanly by a plasma processing device is fixed on a pressing pedestal 7, an anisotropic conductive adhesive 4 is attached to the position of the metal finger, and pre-pressing is carried out for 0.5-1 second by providing the operating conditions of temperature (110+/-10 ℃) and pressure (0.03-0.08MPa) through a pressing joint 1 which can provide temperature and pressure. The effect of second teflon pad 6 is that the pressfitting pedestal 7 of avoiding the metal material produces the indentation to rigidity sheet metal finger end 5, and the effect of first teflon pad 2 avoids the crimping head 1 of metal material to pollute anisotropic conducting resin 4. After prepressing, fixedly adhering the anisotropic conductive adhesive 4 on the finger end 5 of the rigid sheet metal;

as shown in fig. 2, the rigid sheet metal finger tip 5 to which the anisotropic conductive adhesive 4 is fixedly adhered after the prepressing is fixed on the press-fit pedestal, the flexible sheet metal finger tip 3 to be connected with the rigid sheet metal finger tip 5 is precisely aligned, and press-fit is performed for 10 to 12 seconds by a press-fit head which provides a constant temperature (165+/-5 degrees) and pressure (0.12 to 0.20 MPa). The second Teflon cushion 6 is used for preventing the pressing pedestal 7 made of metal from generating indentation on the finger end 5 made of rigid sheet metal, and the first Teflon cushion 2 is used for preventing the pressing joint 1 made of metal from generating indentation on the finger end 3 made of flexible sheet metal. After pressing, the conductive particles between the finger end 3 of the flexible sheet metal and the finger end 5 of the rigid sheet metal in the anisotropic conductive adhesive 4 are exploded under the action of temperature and pressure, the rigid sheet metal and the flexible sheet metal are well conducted, and the conductive particles in the transverse plane and the non-golden finger gap area with insufficient pressure still have high impedance characteristic;

as shown in fig. 3, since the widths of the flexible sheet metal finger tip 3 and the rigid sheet metal finger tip 5 are both small, and are generally designed to be 0.05mm to 0.20mm, and the diameter of the conductive particles in the anisotropic conductive adhesive 4 is only 0.003 mm to 0.005mm (3 μm to 5 μm), in order to describe the lamination effect more intuitively, the cross section of the rigid-flex lamination position of the rigid-flex printed board is described as an enlarged structural schematic diagram. In the figure, the second conductive particles 13 in the anisotropic conductive adhesive 4 between the flexible sheet metal finger 9 and the rigid sheet metal finger 12 still have high impedance characteristics in the transverse direction due to the fact that the second conductive particles 13 are subjected to the pressing condition of pressing for 10-12 seconds by the pressure joint providing constant temperature (165+/-5 ℃) and pressure (0.12-0.20MPa), and the second conductive particles 13 are exploded in the longitudinal direction to complete electrical conduction; the first conductive particles 10 located between the flexible board substrate 8 and the rigid board substrate 11 are not sufficiently pressed by the height difference between the flexible board fingers 9 and the rigid board fingers 12, and the first conductive particles 10 still have high impedance characteristics. And after the pressing is finished, coating a layer of silica gel on the connecting position for protecting the connecting position, and then connecting the rigid plate part of the high-end rigid-flexible printed circuit board and the rigid-flexible part of the low-width golden finger of the flexible board.

The working principle is as follows: the utility model discloses when using, at first set up anisotropic conducting resin 4 in the upper end of rigidity sheet metal finger end 5, then utilize the crimping head 1 that can provide temperature and pressure, carry out the pre-compaction to anisotropic conducting resin 4, the pre-compaction operating condition is: temperature (110+/-10 ℃), pressure (0.03-0.08MPa) and pre-pressing connection time of 0.5-1 second, then arranging the flexible sheet metal finger end 3 at the upper end of the anisotropic conductive adhesive 4, and then blasting the conductive particles in the longitudinal direction of the anisotropic conductive adhesive 4 under the action of the pressing connection head 1 capable of providing pressure and temperature to complete electric conduction, wherein the pressing connection operation conditions are as follows: the temperature (165+/-5 degrees), the pressure (0.12-0.20MPa) and the crimping time are 10-12 seconds, and the rigid-flexible printed circuit board connector is used for realizing the connection of the rigid-flexible printed circuit board.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The utility model provides a connection structure of high-end rigid-flex printed circuit board, includes crimping head (1), pressfitting pedestal (7), flexible board base material (8) and rigid board base material (11) that can provide temperature and pressure, its characterized in that: the utility model discloses a pressure welding joint, including crimping head (1), lower extreme fixedly connected with first teflon pad (2), the upper end fixedly connected with second teflon pad (6) of pressfitting pedestal (7), be provided with flexible sheet metal finger end (3) and rigid sheet metal finger end (5) on flexible sheet base material (8) and rigid sheet base material (11) respectively, rigid sheet metal finger end (5) are located the upper end of second teflon pad (6), the upper end fixed paste of rigid sheet metal finger end (5) has anisotropic conductive adhesive (4), the upper end of anisotropic conductive adhesive (4) is provided with flexible sheet metal finger end (3).

2. The connecting structure of the high-end rigid-flexible printed circuit board according to claim 1, wherein: the temperature range provided by the crimping head (1) is set to be 100-200 ℃, and the pressure range provided by the crimping head (1) is set to be 0.03-0.2 MPa.

3. The connecting structure of the high-end rigid-flexible printed circuit board according to claim 1, wherein: the lower end of the flexible plate base material (8) is fixedly provided with a flexible sheet metal finger (9), and the upper end of the rigid plate base material (11) is fixedly provided with a rigid sheet metal finger (12).

4. The connecting structure of the high-end rigid-flexible printed circuit board according to claim 3, wherein: the flexible sheet metal finger (9) and the rigid sheet metal finger (12) are arranged in an aligned mode, the flexible sheet metal finger (9) and the rigid sheet metal finger (12) are provided with multiple groups, and equidistant gaps are formed between the flexible sheet metal finger (9) and the rigid sheet metal finger (12).

5. The connection structure of high-end rigid-flex printed circuit board according to claim 4, wherein: the anisotropic conductive adhesive (4) comprises first conductive particles (10) and second conductive particles (13), wherein the second conductive particles (13) are the first conductive particles (10) which are pressed by the pressing joint (1).

6. The connecting structure of the high-end rigid-flexible printed circuit board according to claim 5, wherein: the first conductive particles (10) are located in equidistant gaps arranged between a plurality of groups of the flexible sheet metal fingers (9) and the rigid sheet metal fingers (12), and the second conductive particles (13) are located between the flexible sheet metal fingers (9) and the rigid sheet metal fingers (12) which are arranged in an aligned mode.