CN115550484B

CN115550484B - Display screen assembly and flexible circuit board welding method

Info

Publication number: CN115550484B
Application number: CN202210336416.5A
Authority: CN
Inventors: 郭健强; 罗凡; 肖广楠
Original assignee: Honor Device Co Ltd
Current assignee: Honor Device Co Ltd
Priority date: 2022-03-31
Filing date: 2022-03-31
Publication date: 2024-04-05
Anticipated expiration: 2042-03-31
Also published as: CN115550484A

Abstract

The application provides a display screen assembly and a flexible circuit board welding method. The display screen assembly includes: the display screen, the first flexible circuit board and the second flexible circuit board are arranged on the back of the display screen; the first flexible circuit board comprises a first end close to the bottom of the display screen and a second end far away from the bottom of the display screen; the first end is electrically connected with the bottom edge of the display screen, and the second end is provided with at least one first bonding pad; the second flexible circuit board is of a strip-shaped structure and comprises a third end close to the first flexible circuit board and a fourth end far away from the first flexible circuit board along the length direction of the second flexible circuit board; the third end is provided with at least one second bonding pad; the third end is connected with the second bonding pad through the first bonding pad so as to be connected to the second end; the fourth end is configured to connect with a motherboard of the electronic device when the display screen assembly is mounted to the electronic device. According to the technical scheme, the utilization rate of the flexible circuit board substrate board can be improved, and the universality of the display screen assembly is improved.

Description

Display screen assembly and flexible circuit board welding method

Technical Field

The application relates to the technical field of electronic equipment, in particular to a display screen assembly and a flexible circuit board welding method.

Background

In electronic devices, circuit boards are an essential component that can bring together a large number of electrical components and provide them with electrical connections. The flexible circuit board is a kind of circuit board, is a kind of printed circuit board that takes polyimide or polyester film as the substrate to make, has high reliability, excellent flexibility, has the wiring density height, light in weight, thickness are thin, the good characteristics of bendability.

In the process of manufacturing a flexible circuit board, existing manufacturing methods generally include: firstly, manufacturing a whole flexible circuit board substrate, and manufacturing a plurality of flexible circuit boards to be cut on the flexible circuit board substrate; then, integral dicing is performed along the edge of each flexible circuit board to be diced, and the redundant portions are etched away to obtain a plurality of individual flexible circuit boards.

At present, a flexible circuit board used for a mobile phone display screen assembly is generally of an integrated convex structure, the convex structure leads to lower utilization rate of a flexible circuit board substrate, and a waste area is larger, so that waste of substrate plates is caused, and manufacturing cost of the flexible circuit board is higher. In addition, because the display screen components of the electronic devices of different models have different specifications, the flexible circuit board with the integrated structure cannot be commonly used among the display screen components of different specifications.

Disclosure of Invention

The embodiment of the application provides a display screen assembly and a flexible circuit board welding method, which can improve the utilization rate of a substrate plate of the flexible circuit board and the universality of the display screen assembly.

In order to achieve the above purpose, the embodiments of the present application provide the following technical solutions:

in a first aspect, embodiments of the present application provide a display screen assembly, including: the display screen, the first flexible circuit board and the second flexible circuit board are arranged on the back of the display screen; the first flexible circuit board comprises a first end close to the bottom of the display screen and a second end far away from the bottom of the display screen; the first end is electrically connected with the bottom edge of the display screen, and the second end is provided with at least one first bonding pad; the second flexible circuit board is of a strip-shaped structure and comprises a third end close to the first flexible circuit board and a fourth end far away from the first flexible circuit board along the length direction of the second flexible circuit board; the third end is provided with at least one second bonding pad; the third end is connected with the second bonding pad through the first bonding pad so as to be connected to the second end; the fourth end is configured to connect with a motherboard of the electronic device when the display screen assembly is mounted to the electronic device. By adopting the embodiment, the first flexible circuit board and the second flexible circuit board are arranged into the split structure, so that the utilization rate of the substrate board can be improved and the manufacturing cost of the flexible circuit board can be reduced in the preparation process of the flexible circuit board. The first flexible circuit board is electrically connected with the bottom edge of the display screen, the display screen and the first flexible circuit board can be normalized to be suitable for connecting the second flexible circuit boards with various lengths, the display screen is convenient to apply to electronic equipment with different models, and the universality of the display screen assembly is improved.

In one implementation, a substrate layer is arranged on the back of the display screen; the substrate layer comprises a groove facing the first flexible circuit board, and the groove is positioned in a projection area of the first bonding pad on the substrate layer; the grooves are used for filling heat insulation materials when the first bonding pads and the second bonding pads are welded so as to protect the display screen. By adopting the embodiment, the first flexible circuit board and the second flexible circuit board can be welded on the back of the display screen, the display screen is not damaged, the assembly efficiency of the display screen and the flexible circuit board is improved, and the assembly period can be shortened.

In one implementation, a first back adhesive is filled between the substrate layer and the first flexible circuit board, and the first back adhesive is coated annularly around the heat insulation material; the first back adhesive is used for fixing the first flexible circuit board on the surface of the substrate layer so as to form a gap for filling the heat insulation material between the substrate layer and the first flexible circuit board. By adopting the embodiment, the gap of the heat insulating material can be filled with the first back adhesive, and the substrate layer and the first flexible circuit board can be firmer.

In one implementation, a second back glue is filled between the first flexible circuit board and the second flexible circuit board, and the second back glue is coated on one side of the edge of the second end; the second back glue is used for fixing the first flexible circuit board and the second flexible circuit board. By adopting the embodiment, the first flexible circuit board and the second flexible circuit board can be fixed more firmly.

In one implementation, the method further comprises: the shielding layer is arranged on the surface of the second flexible circuit board, which is opposite to the display screen, and covers the second bonding pad. By adopting the embodiment, the welding part of the first bonding pad and the second bonding pad can be prevented from interfering other devices.

In one implementation, the fourth end is provided with a board-to-board connector for connection with a motherboard of the electronic device when the display screen assembly is mounted to the electronic device. By adopting the embodiment, the second flexible circuit board can be connected with the main board through the board-to-board connector, so that the second flexible circuit board and the main board can be detached.

In one implementation, the fourth end is connected to the motherboard of the electronic device by FoB laser welding techniques when the display screen assembly is mounted to the electronic device. By adopting the embodiment, the second flexible circuit board can be connected with the main board in a FoB welding mode, so that a firmer connection effect is achieved between the second flexible circuit board and the main board.

In one implementation, the length of the first end is greater than the length of the third end. By adopting the embodiment, the shape relation between the first flexible circuit board and the second flexible circuit board is limited, the first flexible circuit board can be of a rectangular-like structure, the second flexible circuit board can be of a strip-shaped structure, or the first flexible circuit board can be of a convex-shaped structure, and the second flexible circuit board can be of a strip-shaped structure. The arrangement mode can ensure that the connection process of the first flexible circuit board and the second flexible circuit board can be suitable for various installation requirements.

In a second aspect, an embodiment of the present application further provides a flexible circuit board soldering method, which is applied to the display screen assembly shown in the first aspect and the various implementation manners of the first aspect, and includes: preparing at least one first bonding pad at a second end of the first flexible circuit board, and preparing at least one second bonding pad at a third end of the second flexible circuit board; and welding the first flexible circuit board and the second flexible circuit board through the first bonding pad and the second bonding pad. By adopting the embodiment, the first flexible circuit board and the second flexible circuit board are manufactured into the split structure, so that a plurality of first flexible circuit boards and second flexible circuit boards can be cut from the same flexible circuit board substrate, the utilization rate of the substrate is improved, and the manufacturing cost of the flexible circuit boards is greatly reduced.

In one implementation, the first flexible circuit board and the second flexible circuit board are soldered to each other through the first pad and the second pad, and further comprising: the first end of the first flexible circuit board is soldered to the display screen bottom edge such that the first flexible circuit board is electrically connected to the display screen bottom edge. By adopting the embodiment, the first flexible circuit board is welded to the bottom edge of the display screen, so that the normalization of the first flexible circuit board and the display screen can be realized, and the universality of the display screen is improved.

In one implementation, a groove facing a first flexible circuit board is prepared on a substrate layer of a display screen, and the groove is positioned in a projection area of a first bonding pad on the substrate layer; when the first flexible circuit board and the second flexible circuit board are connected with the second bonding pad through the first bonding pad in a welding way, the groove is filled with heat insulation materials so as to protect the display screen; when the second flexible circuit board has been soldered to the first flexible circuit board, the insulating material is removed. By adopting the embodiment, the problem of influence of welding the second flexible circuit board on the display screen is solved on the basis of realizing normalization of the first flexible circuit board and the display screen.

In one implementation, a first back adhesive is filled between the substrate layer and the first flexible circuit board, and the first back adhesive is coated annularly around the heat insulating material; the first back adhesive is used for fixing the first flexible circuit board on the surface of the substrate layer so as to form a gap for filling the heat insulation material between the substrate layer and the first flexible circuit board. By adopting the embodiment, the gap of the heat insulating material can be filled with the first back adhesive, and the substrate layer and the first flexible circuit board can be firmer.

In one implementation, a second back adhesive is filled between the first flexible circuit board and the second flexible circuit board, and the second back adhesive is coated on one side of the edge of the second end of the first flexible circuit board; the second back glue is used for fixing the first flexible circuit board and the second flexible circuit board. By adopting the embodiment, the first flexible circuit board and the second flexible circuit board can be fixed more firmly.

In one implementation, the first flexible circuit board is prepared into a convex shape, at least one first bonding pad is located on a convex portion of the convex shape, the first bonding pad extends out of a first opening of the middle frame, and the second bonding pad extends out of a second opening of the middle frame, so that the surface, facing away from the first flexible circuit board, of the middle frame is in welded connection with the second bonding pad, and the middle frame is located on one side, facing away from the display screen, of the first flexible circuit board. By adopting the embodiment, the first flexible circuit board and the second flexible circuit board can be prepared into split structures, a plurality of first flexible circuit boards and second flexible circuit boards can be cut out from the same flexible circuit board substrate, the utilization rate of the substrate is improved, and the manufacturing cost of the flexible circuit boards is greatly reduced.

In one implementation, solder connecting the first flexible circuit board to the second flexible circuit board through the first pad to the second pad further comprises: and the fourth end of the second flexible circuit board is buckled with the main board of the electronic equipment through the board-to-board connector. By adopting the embodiment, the second flexible circuit board can be connected with the main board through the board-to-board connector, so that the second flexible circuit board and the main board can be detached.

In one implementation, before the first flexible circuit board and the second flexible circuit board are soldered to each other through the first pad and the second pad, the method further includes: and welding the fourth end of the second flexible circuit board with a main board of the electronic equipment through a FoB welding technology. By adopting the embodiment, the second flexible circuit board can be connected with the main board in a FoB welding mode, so that a firmer connection effect is achieved between the second flexible circuit board and the main board.

In one implementation, a shielding layer is prepared on a surface of the second flexible circuit board facing away from the display screen, and the shielding layer covers the second bonding pad. By adopting the embodiment, the welding part of the first bonding pad and the second bonding pad can be prevented from interfering other devices.

In one implementation, a method for welding a first bonding pad and a second bonding pad includes: laser welding and/or thermo-compression welding. By adopting the embodiment, various welding modes can be provided for the welding process of the first flexible circuit board and the second flexible circuit board so as to adapt to actual demands.

The technical scheme can solve the problems that the flexible circuit board used by the mobile phone display screen assembly at present is of an integrated convex structure, the utilization rate of the substrate of the flexible circuit board is low, the waste area is large, the waste of the substrate plate is caused, and the manufacturing cost of the flexible circuit board is high; meanwhile, the problem that the flexible circuit board of the integrated structure cannot be commonly used among display screen components of different specifications because the display screen components of electronic equipment of different models are different in specification can be solved. According to the technical scheme, the utilization rate of the substrate plate of the flexible circuit board can be improved in the manufacturing process of the flexible circuit board, the manufacturing cost of the flexible circuit board is greatly reduced, and the universality of the display screen assembly is improved.

Drawings

FIG. 1 schematically illustrates an exploded view of the internal structure of an electronic device;

FIG. 2 illustrates a schematic diagram of a different model of flexible circuit board;

FIG. 3 schematically illustrates a flexible circuit board manufacturing process;

FIG. 4 schematically illustrates a motherboard-to-flexible circuit board connection;

FIG. 5 schematically illustrates another connection of a motherboard to a flexible circuit board;

FIG. 6 illustrates a display screen replacement schematic;

FIG. 7 illustrates a schematic diagram of a display screen assembly;

FIG. 8 illustrates a schematic diagram of a first flexible circuit board structure;

FIG. 9 illustrates a first pad distribution pattern diagram;

FIG. 10 schematically illustrates a first pad shape;

FIG. 11 is a schematic diagram illustrating a cross-sectional structure of a display screen assembly;

fig. 12 schematically illustrates a flexible circuit board manufacturing mode;

FIG. 13 illustrates a schematic diagram of a groove shape;

FIG. 14 illustrates a schematic diagram of a groove shape;

FIG. 15 illustrates a schematic diagram of a display screen assembly;

FIG. 16 illustrates a schematic diagram of a display screen assembly;

FIG. 17 illustrates a schematic diagram of a display screen assembly;

FIG. 18 illustrates a schematic diagram of a display screen assembly;

FIG. 19 illustrates a schematic diagram of a display screen assembly;

FIG. 20 schematically illustrates a flow chart of a method of soldering a flexible circuit board;

FIG. 21 illustrates a flow diagram of a flexible circuit board soldering method;

fig. 22 schematically illustrates a flow chart of a flexible circuit board soldering method;

FIG. 23 illustrates a flow diagram of a flexible circuit board soldering method;

fig. 24 schematically illustrates a flow chart of a flexible circuit board soldering method;

fig. 25 schematically illustrates a flow chart of a flexible circuit board soldering method;

fig. 26 is a schematic diagram illustrating a position of a flexible circuit board soldering method;

fig. 27 schematically illustrates a flow chart of a flexible circuit board soldering method.

Detailed Description

The technical solutions of the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application.

In the description of the present application, "/" means "or" unless otherwise indicated, for example, a/B may mean a or B. "and/or" herein is merely an association relationship describing an association object, and means that three relationships may exist, for example, a and/or B may mean: a exists alone, A and B exist together, and B exists alone. Furthermore, "at least one" means one or more, and "a plurality" means two or more. The terms "first," "second," and the like do not limit the number and order of execution, and the terms "first," "second," and the like do not necessarily differ.

In this application, the terms "exemplary" or "such as" are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "for example" should not be construed as preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "such as" is intended to present related concepts in a concrete fashion.

In order to facilitate the technical personnel to understand the technical scheme of the embodiment of the application, the technical terms related to the embodiment of the application are explained below.

1. The flexible circuit board (Flexible Printed Circuit, FPC) is a printed circuit board which is made of polyimide or polyester film as a base material and has high reliability, excellent flexibility, high wiring density, light weight, thin thickness and good flexibility.

2. The anisotropic conductive adhesive film (Anisotropic Conductive Film, ACF) comprises a resin adhesive and conductive particles, and is characterized in that the vertical direction of the ACF is the conductive ventilation direction, the horizontal plane is an insulating plane, the ACF has resistance characteristics, the characteristics of the vertical direction and the characteristics of the horizontal plane have obvious difference, the conductive particles can be used for connecting electrodes between an IC chip and a substrate to conduct the ACF, and meanwhile, conduction short circuits between two adjacent electrodes can be avoided, so that the purpose of conducting the ACF only in the vertical direction is achieved.

3. The Board-To-Board (BTB) connector can be used for connecting a flexible circuit Board and a main Board, and has the characteristics of strong transmission capability, light weight, stable high-frequency transmission, no need of welding and noise reduction.

4. The soft Board and hard Board combined welding technology (FoB) is a welding technology which can be used for welding a flexible circuit Board and a main Board. The technical process comprises the following steps: heating the bonding pad on the main board by laser to melt the bonding pad; under the extrusion action of the flexible circuit board, the solder after melting the bonding pad flows from the welding copper of the flexible circuit board to one side of the flexible circuit board, which is opposite to the main board; after the soldering tin is solidified, the soldering tin is connected with the soldering copper to fix the flexible circuit board and the main board, and the electric connection of the flexible circuit board and the main board is realized.

Fig. 1 exemplarily shows an exploded view of an internal structure of an electronic device. As shown in fig. 1, the electronic device may include: a display screen 1, a flexible circuit board 2, a main board 3 and a middle frame 4. The flexible circuit board 2 sets up the display screen 1 back that is arranged in, and the center 4 sets up in the side that the flexible circuit board 2 was facing away from the display screen 1 for fixed display screen 1 and flexible circuit board 2, and mainboard 3 sets up the side that is facing away from the display screen 1 on center 4, and mainboard 3 is connected with the flexible circuit board 2 electricity in the opening part of center 4.

Since the sizes and internal structures of the electronic devices of different models are different, the flexible circuit board 2 needs to be adaptively designed according to the sizes and internal structures of the electronic devices. Different types of electronic devices correspond to different types of flexible circuit boards 2.

Fig. 2 illustrates schematic diagrams of different types of flexible circuit boards. As shown in fig. 2, taking a mobile phone as an example, the flexible circuit board 2 on the back of the display screen 1 is generally in a convex shape, and may include a rectangular-like main body portion 2-1 and a strip-like protruding portion 2-2, where the main body portion 2-1 and the protruding portion 2-2 are integrally formed. The long side of one side of the main body 2-1 is generally welded to the bottom edge of the display screen 1, the long side of the other side is connected to the short side of one side of the protruding portion 2-2, and the short side of the other side of the protruding portion 2-2 extends away from the main body 2-1, and finally is connected to the motherboard 3 of the electronic device, and the extending direction is generally the length direction of the electronic device. It will be appreciated that the length of the protruding portion 2-2 of the flexible circuit board needs to be adapted to the size, internal layout, etc. of the electronic device. In general, the farther the distance between the main board 3 and the bottom of the display screen 1, the longer the length of the convex portion 2-2; the closer the distance between the main board 3 and the bottom of the display screen 1, the shorter the length of the protruding portion 2-2. Therefore, since the different electronic devices have different sizes and different internal layouts, the lengths of the protruding portions 2-2 of the flexible circuit boards 2 in the different electronic devices are greatly different, and thus, it is difficult to adapt the flexible circuit boards 2 of the same size to different models of electronic devices.

Fig. 3 schematically illustrates a flexible circuit board manufacturing mode. As shown in fig. 3, in the process of manufacturing the flexible circuit board 2, the conventional manufacturing method generally includes: firstly, manufacturing a whole flexible circuit board substrate, and manufacturing a plurality of flexible circuit boards 2 to be cut on the flexible circuit board substrate; then, integral dicing is performed along the edge of each flexible circuit board 2 to be diced, and the surplus portion is etched away to obtain a plurality of individual flexible circuit boards 2. At present, the flexible circuit board 2 used for the mobile phone display screen assembly is generally in an integrated convex structure, and the convex structure leads to lower utilization rate of the substrate and larger waste area, so that waste of the substrate board is caused, and the manufacturing cost of the flexible circuit board is higher.

Fig. 4 schematically illustrates a connection between a motherboard and a flexible circuit board. As shown in fig. 4, the surface of the flexible circuit board 2 facing away from the display screen 1 is provided with a terminal 51 of the BTB connector 5, the surface of the main board 3 facing the display screen 1 is provided with a base 52 of the BTB connector 5, and the terminal 51 and the base 52 are buckled at the opening of the middle frame 4.

In the foregoing embodiment, the long side of the main body 2-1 is generally connected with the bottom edge of the display screen 1 by ACF welding, and the flexible circuit board 2 is in an integrated structure, so when the terminal 51 and the base 52 are buckled at the opening of the middle frame 4, the assembled display screen 1 and the flexible circuit board 2 are buckled with the assembled middle frame 4 and the motherboard 3, or the assembled display screen 1 and the flexible circuit board 2 are assembled with the middle frame 4 and then buckled with the motherboard 3. When the display screen 1 is damaged, the main board 3 and the middle frame 4 need to be disassembled to replace the display screen 1 and the flexible circuit board 2 as a whole.

Fig. 5 schematically illustrates another connection mode of the motherboard and the flexible circuit board. As shown in fig. 5, a main board pad 31 is arranged on the surface of the main board 3 close to the display screen 1, a hollow welding column 223 is arranged on the surface of one short side of the protruding part 2-2, which faces away from the display screen 1, and the main board pad 31 can be melted by laser through FoB laser welding technology, specifically the main board pad 31 on the main board 3 is heated by the laser to melt the main board pad 31; under the extrusion action of the flexible circuit board 2, the melted soldering tin of the main board bonding pad 31 flows from the welding post 223 to one side of the flexible circuit board 2, which is opposite to the main board 3; after the soldering tin is solidified, the soldering tin is connected with the welding post 223 to fix the flexible circuit board 2 and the main board 3 at the opening of the middle frame 4, so as to realize the electrical connection of the flexible circuit board 2 and the main board 3. When the display screen of the electronic device is damaged, since the long side of one side of the main body part 2-1 is welded and connected with the bottom edge of the display screen 1 through the ACF, and the short side of one side of the protruding part 2-2 is welded and connected with the main board 3 through the FoB laser welding technology, when the display screen 1 is damaged, the whole display screen 1 and the flexible circuit board 2 need to be replaced, and the welded part of the short side of one side of the protruding part 2-2 and the main board 3 needs to be separated, so that the disassembly difficulty is high.

Fig. 6 schematically illustrates a display screen replacement mode. As shown in fig. 6, taking the connection mode of the motherboard 3 and the flexible circuit board 2 as BTB connection as an example, the terminal 51 and the base 52 are fastened at the connection point a, when the display screen is replaced, only the display screen 1 connected with the same type flexible circuit board 2 can be replaced, so as to ensure that the flexible circuit board 2 connected with the replaced display screen 1 is provided with the terminal 51 at the same position, and can be connected with the base 52 at the connection point a. If the display screen 1 connected with the flexible circuit boards 2 of different types is replaced, the lengths of the protruding portions 2-2 of the flexible circuit boards 2 are different, and the terminals 51 of the short sides of one sides of the protruding portions 2-2 cannot be buckled with the base 52, so that the problem that the display screen 1 connected with the flexible circuit boards 2 of different types cannot be commonly used exists in the existing display screen replacement process.

In order to solve the above problems, embodiments of the present application provide a display screen assembly.

Fig. 7 is a schematic diagram schematically illustrating a first structure of a display screen assembly according to an embodiment of the present application. As shown in fig. 7, the display screen assembly includes: the display screen 1, and a first flexible circuit board 21 and a second flexible circuit board 22 provided on the back surface of the display screen 1. It should be noted that, in the embodiment of the present application, the first flexible circuit board 21 and the second flexible circuit board 22 are in a split structure.

Wherein the first flexible circuit board 21 comprises a first end 211 near the bottom of the display screen 1 and a second end 212 far from the bottom of the display screen 1; the first end 211 is electrically connected to the bottom edge of the display screen 1. The second end 212 is provided with at least one first pad 2121.

The second flexible circuit board 22 has a strip-shaped structure, and includes a third end 221 close to the first flexible circuit board 21 and a fourth end 222 far from the first flexible circuit board 21 along the length direction thereof; the third terminal 221 is provided with at least one second pad 2211; the third terminal 221 is connected to the second pad 2211 through the first pad 2121 to be connected to the second terminal 212.

In one implementation, the first flexible circuit board 21 may be configured in a rectangular-like structure as shown in fig. 8, and the first end 211 may be fixed to the back surface of the display screen 1 by welding or bonding, and electrically connected to the bottom edge of the display screen 1. Illustratively, the first end 211 is fixed to the back surface of the display screen 1 by means of ACF soldering, and conductive particles in the ACF may electrically connect the first end 211 with the display screen 1.

As further shown in fig. 7, the second end 212 is provided with at least one first pad 2121. The first pads 2121 may be provided in a staggered distribution or a side-by-side distribution as shown in fig. 9 to reduce the pressure at the time of soldering by a suitable distribution. The first pad 2121 may be provided in at least one of a circular shape, a groove shape, and a peanut shape as shown in fig. 10. The bonding capability at the time of soldering of the first bonding pads 2121 of different shapes is different, and the shape of the first bonding pad 2121 may be designed according to actual circumstances. The shape of the first pad 2121 shown in the embodiment of the present application affects the bonding density of the first pad 2121 and the second pad 2211 during the bonding process.

The third terminal 221 is connected to the second pad 2211 through the first pad 2121 to be connected to the second terminal 212. Wherein the second pad 2211 is disposed corresponding to the shape of the first pad 2121 so that the first pad 2121 is tightly bonded to the second pad 2211. It should be noted that, the second flexible circuit board 22 is further provided with at least one first solder hole 2212, and the first solder hole 2212 is disposed at a position corresponding to the second solder pad 2211, and is a through hole from a surface of the second flexible circuit board 22 facing away from the first flexible circuit board 21 to a surface of the second solder pad 2211 adjacent to the first flexible circuit board 21. During the soldering process, the solder is injected from the first soldering hole 2212, and the melted solder can make the first soldering pad 2121 and the second soldering pad 2211 connected in a soldering manner.

Fig. 11 schematically illustrates a cross-sectional structure of a display screen assembly. As shown in fig. 11, after the first pad 2121 is tightly soldered to the second pad 2211, the first pad 2121 and the second pad 2211 are soldered to the first pad 2121 and the second pad 2211, and the maximum thickness of the second flexible circuit board 22 is not more than 0.25 mm, so that the thickness of the flexible circuit board including the soldering structure shown in the application is not significantly increased compared with the thickness of the conventional flexible circuit board, and thus the thickness of the electronic device is not increased. In the process of soldering the first pad and the second pad, it is necessary to inject solder from at least one first soldering hole 2212 so that the solder flows out from the surface of the first soldering hole 2212 facing the first pad 2121, so that the first pad 2121 is soldered to the second pad 2211, the soldering position of the first pad 2121 and the second pad 2211 actually includes a solder thickness, the solder thickness is determined according to the solder material actually used, the solder time and the solder temperature, and the solder thickness is not shown in the schematic cross-sectional structure and the schematic cross-sectional structure described below, and needs to be considered in the actual setting.

In the practical arrangement of the first bonding pad 2121, the second bonding pad 2211 and the first bonding hole 2212 in the present application, including but not limited to the embodiment shown in the embodiment and the drawings, in the specific arrangement, the arrangement mode that the first bonding hole 2212 is not arranged on the second bonding pad 2211, the surface of the side, facing the display screen, of the second bonding pad 2211 is provided with prefabricated soldering tin, and the second bonding pad 2211 and the first bonding pad 2121 are connected by thermal compression soldering may also be adopted; or the second bonding pad 2211 is not provided with the first bonding hole 2212, the first bonding pad 2121 is provided with the second bonding hole, the surface of the second bonding pad 2211 facing the display screen is provided with the prefabricated solder, the second bonding pad 2211 and the first bonding pad 2121 are welded by hot pressing, so that the prefabricated solder flows into the second bonding hole, and the second bonding pad 2211 and the first bonding pad 2121 are welded and connected. It should be noted that, in the present application, a single-sided welding hole setting, a double-sided welding hole setting, a welding hole setting mode without setting a welding hole, and other specific embodiments may be adopted, and the welding density of the first bonding pad 2121 and the second bonding pad 2211 in the welding process is affected by the distribution mode of the welding holes and the shape of the welding hole. In some embodiments, the shapes of the first welding hole 2212 and the second welding hole may be at least one of a circular shape, a groove shape, a peanut shape, and a semicircular shape, and the number of the first welding hole 2212 and the second welding hole is not limited in the embodiments of the present application.

Fig. 12 schematically illustrates a preparation manner of a flexible circuit board according to an embodiment of the present application. As shown in fig. 12, since the first flexible circuit board 21 and the second flexible circuit board 22 that are set in the embodiment of the present application are of a split structure, and the first flexible circuit board 21 may be set to be rectangular-like, and the second flexible circuit board 22 may be set to be bar-like and be of a more regular shape, compared with the conventional integrated structure of the convex flexible circuit board 2, the embodiment of the present application shows that the preparation method can be more flexibly laid out on the substrate board of the flexible circuit board. In a specific implementation, the first flexible circuit board 21 may be intensively laid out in one area of the flexible circuit board substrate board, and the second flexible circuit board 22 may be intensively laid out in another area; or the first flexible circuit board 21 and the second flexible circuit board 22 are mixed and laid out on the flexible circuit board substrate board; or the first flexible circuit board 21 is intensively laid out in the central area of the flexible circuit board substrate board, and the second flexible circuit board 22 is laid out in the edge area. The specific layout modes of the first flexible circuit board 21 and the second flexible circuit board 22 can be set according to actual conditions, and compared with the layout modes of the first flexible circuit board 21 and the second flexible circuit board 22 shown in fig. 3, the convex-shaped flexible circuit board 2 with the traditional integrated structure can improve the substrate utilization rate by more than 33.3%, and the manufacturing cost of the flexible circuit board is greatly reduced.

Since the first flexible circuit board 21 and the second flexible circuit board 22 need to be disposed on the back surface of the display screen 1, a high temperature is generated during the soldering process of the first pad 2121 and the second pad 2211. Therefore, in order to ensure that the soldering process of the first pad 2121 and the second pad does not affect the display screen 1, in one implementation, as shown in fig. 13, the back surface of the display screen 1 is further provided with a groove 111.

In general, the display 1 is provided with a substrate layer 11 and an organic material layer 12 on the back surface, and the substrate layer 11 may be a metal material, for example: copper, steel, aluminum, etc., to which the present embodiments are not limited. In this embodiment, the groove 111 may be disposed on a side of the substrate layer 11 facing the first flexible circuit board 21, and the groove 111 is located in a projection area of the first bonding pad 2121 on the substrate layer 11, and the groove 111 is used for filling the heat insulation material 8 during the first bonding pad 2121 and the second bonding to protect the display screen.

It should be noted that, the shape of the groove 111 includes, but is not limited to, a closed square groove as shown in fig. 13, and may also be a closed circular groove, wherein the closed square groove and the closed circular groove are non-communicating grooves in which the wall surface of the groove 111 has a certain distance from the edge of the substrate layer 11; or as a through square groove as shown in fig. 14, wherein the through groove is a groove in which the groove 111 communicates with the edge of the substrate layer 11.

The display screen 1 in the embodiment of the present application may be an Organic Light-Emitting Diode (OLED) display screen. The basic structure of the OLED display screen comprises: indium Tin Oxide (ITO) glass, a layer of organic luminescent material on ITO glass that is tens of nanometers thick, and a low work function metal electrode. The organic light emitting material may correspond to the organic material layer 12 in the embodiment of the present application, and the metal electrode may correspond to the substrate layer 11 in the embodiment of the present application.

It should be noted that, when the first bonding pad 2121 and the second bonding pad 2211 are welded on the back surface of the display screen, the welding temperature of the high-temperature welding solder paste SAC305 is 260-280 ℃; the welding temperature of the solder paste SnBiAg is 180-220 ℃; far exceeding the temperature resistance of the display screen 1. Therefore, in the embodiment of the application, when the first pad 2121 and the second pad 2211 are welded, the heat insulation material 8 can be added at the position 0.1 mm-0.3 mm outside the welding position of the first pad 2121 and the second pad 2211, and the influence of the high temperature generated by welding on the display screen 1 is isolated by the heat insulation material 8. In the present embodiment, the distance between the bottom of the groove 111 and the first flexible circuit board is preferably not more than 0.3mm, and therefore, the thickness of the heat insulating material 8 is also preferably not more than 0.3mm.

As further shown in fig. 13, in one implementation, the display screen assembly further includes a shielding layer 6. The shielding layer 6 is disposed on a surface of the second flexible circuit board 22 facing away from the display screen 1, and covers the second bonding pads 2211. Since the first pad 2121 and the second pad 2211 are both made of metal, the welding position of the first pad 2121 and the second pad 2211 may interfere with other devices in the electronic device during use, and therefore, the shielding layer 6 is used for preventing the welding position of the first pad 2121 and the second pad 2211 from interfering with other devices in the electronic device.

It should be noted that, in the prior art, the surface of the back of the display screen 1 and the surface of the flexible circuit board 2, which is close to one side of the display screen 1, are often provided with an anti-interference shielding layer for preventing other devices of the electronic apparatus from interfering with the display screen 1 and the flexible circuit board 2, in this embodiment of the application, the shielding layer is also provided between the back of the display screen 1 and one side of the first flexible circuit board 21 and the second flexible circuit board 22, which is close to the back of the display screen 1, for anti-interference, and since the setting of the anti-interference shielding layer is the same as that of the prior art, the description is omitted herein, and therefore, only the newly added shielding layer 6 is described, i.e. the shielding layer 6 as shown in fig. 13.

Fig. 15 is a second schematic view schematically illustrating a structure of a display screen assembly according to an embodiment of the present application. As shown in fig. 15, in one implementation, to better protect the display during the soldering of the first pad 2121 and the second pad 2211, the display assembly may further include: a first back adhesive 71; the first back adhesive 71 is filled between the substrate layer 11 and the first flexible circuit board 21, and the first back adhesive 71 is annularly coated around the heat insulating material 8, and the first back adhesive 71 is used for fixing the first flexible circuit board 21 on the surface of the substrate layer 11, so that a gap for filling the heat insulating material 8 is formed between the substrate layer 11 and the first flexible circuit board 21.

When the groove 111 is filled with the heat insulating material 8, the groove 111 needs to have a sufficient depth in order to ensure that the heat insulating material 8 has a certain thickness to satisfy the heat insulating requirement. However, if the depth of the groove 111 is to be increased, it is necessary to increase the thickness of the substrate layer 11, resulting in an excessive cost of the substrate layer 11. By filling the first back adhesive 71 between the substrate layer 11 and the first flexible circuit board 21, the distance between the substrate layer 11 and the first flexible circuit board 21 is increased, and the increased distance can be used for accommodating the first back adhesive 71 with larger thickness, so that the thickness of the heat insulation material 8 is ensured without increasing the thickness of the substrate layer 11.

It should be noted that, when the groove 111 is a closed square groove as shown in fig. 13, or is a closed circular groove, the heat insulation material 8 is adapted to the shape of the groove 111, the first back adhesive 71 is annularly coated around the heat insulation material 8, and when the groove 111 is a through square groove as shown in fig. 14, the first back adhesive 71 is coated on the closed side of the through square groove.

Fig. 16 illustrates a third structural schematic diagram of a display screen assembly according to an embodiment of the present application. As shown in fig. 16, in one implementation, to ensure stability of the second flexible circuit board 22 after the first flexible circuit board 21 is soldered with the second flexible circuit board 22, the display screen assembly may further include: a second back adhesive 72; the second back glue 72 is filled between the first flexible circuit board 21 and the second flexible circuit board 22, and the second back glue 72 is located at the edge of the second end 212, and the second back glue 72 is used for fixing the first flexible circuit board 21 and the second flexible circuit board 22.

Fig. 17 illustrates a fourth schematic diagram of a display screen assembly structure according to an embodiment of the present application. As shown in fig. 17, in one implementation, the fourth end 222 is provided with a terminal 51 of the BTB connector 5, the terminal 51 being connected with a housing 52 provided on the motherboard 3 when the display screen assembly is mounted to an electronic device.

In the specific implementation process, after the first bonding pad 2121 and the second bonding pad 2211 are tightly welded, the middle frame 4 is buckled on the side of the first flexible circuit board 21 opposite to the display screen 1; so that the terminal 51 is electrically connected to the housing 52 from the opening of the center 4.

Fig. 18 illustrates a fifth schematic diagram of a display screen assembly structure according to an embodiment of the present application. As shown in fig. 18, in one implementation, the fourth end 222 is connected to the motherboard 3 by FoB laser welding techniques. In a specific implementation, the main board bonding pad 31 is heated by laser to melt the main board bonding pad 31, and under the extrusion action of the second flexible circuit board 22, the melted soldering tin of the main board bonding pad 31 flows from the welding post 223 to the side of the second flexible circuit board 22, which is opposite to the main board 3; after the solder is cured, the solder is connected with the solder post 223 to fix the second flexible circuit board 22 and the motherboard 3, and to realize electrical connection between the second flexible circuit board 22 and the motherboard 3.

It should be noted that, the motherboard bonding pad 31 and the bonding post 223 are both located at the opening of the middle frame 4, so that when the motherboard bonding pad 31 melts and resolidifies, the motherboard 3, the middle frame 4 and the fourth end 222 can be bonded together.

Fig. 19 is a schematic diagram schematically illustrating a sixth structure of a display screen assembly according to an embodiment of the present application. As shown in fig. 19, the first flexible circuit board 21 may be configured in a convex structure as shown in fig. 19, the first end 211 may be fixed on the back surface of the display screen 1 by welding or bonding, the second end 212 is disposed on a side of the convex portion away from the bottom of the display screen 1, and the first end 211 is electrically connected to the edge of the bottom of the display screen. The second end 212 is provided with at least one first pad 2121. The second flexible circuit board 22 has a strip-shaped structure, and includes a third end 221 close to the first flexible circuit board 21 and a fourth end 222 far from the first flexible circuit board 21 along a length direction thereof, and the third end 221 is provided with at least one second bonding pad 2211. The length of the first end 211 is greater than the length of the third end 221.

The embodiments of the present application include, but are not limited to, the first to sixth structures of the display screen assembly provided above, and further include a display screen assembly formed by forming one or more combinations of technical features in the foregoing embodiments, which is easy to understand that, based on several embodiments provided in the present application, a person skilled in the art may combine, split, reorganize, etc. the embodiments of the present application to obtain other embodiments, where none of these embodiments exceeds the protection scope of the present application.

In some embodiments, the display screen assembly provided by the embodiments of the present application may be used in an electronic device. The electronic device in embodiments of the present application may be for example a tablet (portable android device,PAD), personal digital processing (personal digital assistant, PDA), handheld device with wireless communication function, computing device, vehicle mounted device or wearable device, virtual Reality (VR) terminal device, augmented reality (augmented reality, AR) terminal device, wireless terminal in industrial control (industrial control), wireless terminal in unmanned driving (self driving), wireless terminal in remote medical (remote medical), wireless terminal in smart grid (smart grid), wireless terminal in transportation security (transportation safety), wireless terminal in smart city (smart city), wireless terminal in smart home (smart home), or the like, mobile terminal with touch screen or fixed terminal. The electronic device according to the present application can be mounted Harmony/>Or other operating system, to which the present application is not limited.

The display screen assembly can solve the problems that the flexible circuit board used by the mobile phone display screen assembly at present is of an integrated convex structure, the utilization rate of the substrate of the flexible circuit board is low, the waste area is large, the waste of the substrate plate is caused, and the manufacturing cost of the flexible circuit board is high; meanwhile, the problem that the flexible circuit board of the integrated structure cannot be commonly used among display screen components of different specifications because the display screen components of electronic equipment of different models are different in specification can be solved. According to the technical scheme, the utilization rate of the substrate plate of the flexible circuit board can be improved in the manufacturing process of the flexible circuit board, the manufacturing cost of the flexible circuit board is greatly reduced, and the universality of the display screen assembly is improved.

The embodiment of the application also provides a flexible circuit board welding method which can be applied to a flexible circuit board welding process of electronic equipment, in particular to the electronic equipment with a display screen assembly. The flexible circuit board welding method provided by the embodiment of the application can be used for preparing the display screen assembly in the embodiment shown in the fig. 7 to 19 and the display screen assembly formed by one or more combination modes in the embodiment shown in the fig. 7 to 19.

Fig. 20 is a schematic diagram illustrating a first flow of a method for soldering a flexible circuit board according to an embodiment of the present application.

The method provided in the embodiments of the present application is specifically described below, and as shown in fig. 20, the method may include the following steps:

s101: a first flexible circuit board 21 and a second flexible circuit board 22 are prepared.

In one implementation, the first flexible circuit board 21 and the second flexible circuit board 22 may be prepared in the manner of preparing the flexible circuit boards as shown in fig. 12. Because the first flexible circuit board 21 and the second flexible circuit board 22 that set up in this application embodiment are split structure, and first flexible circuit board 21 can be prepared to the class rectangle, and second flexible circuit board 22 can be prepared to the bar, all is more regular shape, consequently in the protruding font flexible circuit board 2 of traditional integrated structure, can more nimble overall arrangement on flexible circuit board base plate board. In a specific implementation, the first flexible circuit board 21 may be intensively laid out in one area of the flexible circuit board substrate board, and the second flexible circuit board 22 may be intensively laid out in another area; or the first flexible circuit board 21 and the second flexible circuit board 22 are mixed and laid out on the flexible circuit board substrate board; or the first flexible circuit board 21 is intensively laid out in the central area of the flexible circuit board substrate board, and the second flexible circuit board 22 is laid out in the edge area. The specific layout modes of the first flexible circuit board 21 and the second flexible circuit board 22 can be set according to actual conditions, and compared with the layout modes of the first flexible circuit board 21 and the second flexible circuit board 22 shown in fig. 3, the convex-shaped flexible circuit board 2 with the traditional integrated structure can improve the substrate utilization rate by more than 33.3%, and the manufacturing cost of the flexible circuit board is greatly reduced.

S102: at least one first pad 2121 is prepared at the second end 212 of the first flexible circuit board 21 and at least one second pad 2211 is prepared at the third end 221 of the second flexible circuit board 22.

The first pads 2121 may be prepared in a staggered distribution or a parallel distribution as shown in fig. 9 to reduce pressure during soldering by a suitable distribution. The first pad 2121 may be prepared in at least one of a circular shape, a groove shape, and a peanut shape as shown in fig. 10. The bonding capability at the time of soldering of the first bonding pads 2121 of different shapes is different, and the shape of the first bonding pad 2121 may be designed according to actual circumstances. Wherein the second pad 2211 is prepared corresponding to the shape of the first pad 2121 so that the first pad 2121 is tightly bonded to the second pad 2211.

Note that, the bonding method between the first pad 2121 and the second pad 2211 includes: laser welding and/or thermo-compression welding. In particular, the laser welding may use a high-energy density laser beam as a heat source to heat the surface of the second bonding pad 2211 by laser radiation, so that the second bonding pad 2211 is melted and is tightly welded with the first bonding pad 2121. The thermocompression bonding is to use heat and pressure to plastically deform the first bonding pad 2121 and the second bonding pad 2211, and at the same time, to break the oxide layer on the bonding interface, so that the attractive force range of atoms is reached between the first bonding pad 2121 and the second bonding pad 2211, thereby generating attractive force between atoms and achieving the bonding purpose.

S103: preparing a groove 111 facing the first flexible circuit board 21 on the substrate layer 11 of the display screen 1, wherein the groove 111 is positioned in a projection area of the first bonding pad 2121 on the substrate layer 11; the grooves 111 are filled with the heat insulating material 8.

The shape of the groove 111 includes, but is not limited to, a closed square groove as shown in fig. 13, and may also be provided as a closed circular groove, wherein the closed square groove and the closed circular groove are non-communicating grooves in which the wall surface of the groove 111 has a certain distance from the edge of the substrate layer 11; or as a through square groove as shown in fig. 14, wherein the through groove is a groove in which the groove 111 communicates with the edge of the substrate layer 11. Because the welding temperature of the high-temperature welding solder paste SAC305 is 260-280 ℃ when the first bonding pad 2121 and the second bonding pad 2211 are welded on the back surface of the display screen; the welding temperature of the solder paste SnBiAg is 180-220 ℃; far exceeding the temperature resistance of the display screen 1. Therefore, in the embodiment of the application, when the first pad 2121 and the second pad 2211 are welded, the heat insulation material 8 can be added at the position 0.1 mm-0.3 mm outside the welding position of the first pad 2121 and the second pad 2211, and the influence of the high temperature generated by welding on the display screen 1 is isolated by the heat insulation material 8. In the present embodiment, the distance between the bottom of the groove 111 and the first flexible circuit board is preferably not more than 0.3mm, and therefore, the thickness of the heat insulating material 8 is also preferably not more than 0.3mm.

S104: the first end 211 of the first flexible circuit board 21 is soldered to the bottom edge of the display screen 1 so that the first flexible circuit board 21 is electrically connected to the bottom edge of the display screen 1.

The first end 211 may be fixed on the back surface of the display screen 1 by means of ACF welding, and conductive particles in the ACF may electrically connect the first end 211 with the display screen 1. It should be noted that the embodiments of the present application include, but are not limited to, ACF soldering, but may also be other soldering, crimping, and bonding.

S105: the first flexible circuit board 21 and the second flexible circuit board 22 are solder-connected to the second pad 2211 through the first pad 2121, and the insulating material 8 is removed. It should be noted that the heat insulating material 8 needs to be removed after the soldering is completed, otherwise, the performance of the display screen 1 and the first flexible circuit board 21 and the second flexible circuit board 22 is affected.

S106: a shielding layer 6 is prepared on the surface of the second flexible circuit board 22 facing away from the display screen 1, and the shielding layer 6 covers the second bonding pads 2211. Since the first pad 2121 and the second pad 2211 are both made of metal, the welding position of the first pad 2121 and the second pad 2211 may interfere with other devices in the electronic device during use, and therefore, the shielding layer 6 is used for preventing the welding position of the first pad 2121 and the second pad 2211 from interfering with other devices in the electronic device.

Fig. 21 is a schematic diagram illustrating a second flow chart of a flexible circuit board soldering method according to an embodiment of the present application.

The method provided in the embodiment of the present application is specifically described below, and as shown in fig. 21, the method may further include the following steps:

s107: the first back glue 71 is filled between the substrate layer 11 and the first flexible circuit board 21, the first back glue 71 is annularly coated around the heat insulation material 8, and the first back glue 71 is used for fixing the first flexible circuit board 21 on the surface of the substrate layer, so that a gap for filling the heat insulation material 8 is formed between the substrate layer 11 and the first flexible circuit board 21.

In a specific implementation, step S107 is performed after step S105 is completed. Although the first end 211 has been welded to the bottom edge of the display screen 1 and the second flexible circuit board 22 has been welded to the first flexible circuit board 21, both the first flexible circuit board 21 and the second flexible circuit board 22 have been fixed, due to the arrangement of the heat insulating material 8 during welding, a gap may exist between the surface of the first flexible circuit board 21 on the side close to the display screen 1 and the surface of the display screen 1 on the side close to the first flexible circuit board 21, and therefore, the first back adhesive 71 will be filled at the gap to ensure the stability of the first flexible circuit board 21.

Fig. 22 is a schematic diagram illustrating a third flow chart of a flexible circuit board soldering method according to an embodiment of the present application.

The method provided in the embodiment of the present application is specifically described below, and as shown in fig. 22, the method may further include the following steps:

s108: filling a second back glue 72 between the first flexible circuit board 21 and the second flexible circuit board 22, wherein the second back glue 72 is positioned at the edge of the second end 212 of the first flexible circuit board 21; the second back adhesive 72 is used for fixing the first flexible circuit board 21 and the second flexible circuit board 22.

In a specific implementation, step S108 may be performed after step S105 is completed. Because the first flexible circuit board 21 and the second flexible circuit board 22 are of split structures, and the second flexible circuit board 22 is welded on the surface of the side, opposite to the display screen 1, of the first flexible circuit board 21, a gap is reserved between the second flexible circuit board 22 and the surface, opposite to the display screen 1, of the first flexible circuit board 1, so that the stability of the second flexible circuit board 22 is poor, and therefore the second back glue 72 is filled at the edge of the second end 212 of the first flexible circuit board 21, and the first flexible circuit board 21 and the second flexible circuit board 22 can be fixed.

Fig. 23 is a schematic flow chart of a fourth method for soldering a flexible circuit board according to an embodiment of the present application.

The method provided in the embodiment of the present application is specifically described below, and as shown in fig. 23, the method may further include the following steps:

s109: terminal 51 of BTB connector 5 is prepared on fourth end 222.

In a specific implementation, the terminal 51 may be manufactured after the second flexible circuit board 22 is manufactured, or may be manufactured after the second bonding pad 2211 is manufactured, and the terminal 51 only needs to be manufactured before step S105, so as to avoid the influence of the terminal 51 being manufactured when the second flexible circuit board 22 is soldered to the first flexible circuit board 21 on the display screen 1.

With continued reference to fig. 23, the method for soldering a flexible circuit board in the present application further includes:

s110: after the second flexible circuit board 22 is soldered to the first flexible circuit board 21, the middle frame 4 is assembled such that the middle frame 4 is used to fix the display screen 1, the first flexible circuit board 21, and the second flexible circuit board 22, wherein the terminals 51 are located at the openings of the middle frame 4.

S111: a seat 52 is prepared on the main board 3.

In a specific implementation, the base 52 may be prepared after the preparation of the terminal 51 is completed, so that the terminal 51 can be correspondingly buckled with the base 52.

S112: the main board 3 is fastened to the middle frame 4 so that the terminals 51 are fastened to the base 52.

Fig. 24 is a schematic diagram illustrating a fifth flow chart of a flexible circuit board soldering method according to an embodiment of the present application.

The method provided in the embodiments of the present application is specifically described below, and as shown in fig. 24, the method may further include the following steps:

s113: a hollow solder post 223 is provided at the surface of the fourth end 222 facing away from the display screen 1.

In a specific implementation, the solder columns 223 may be prepared after the first flexible circuit board 21 and the second flexible circuit board 22 are prepared, or may be prepared after the at least one second bonding pad 2211 is prepared.

S114: a motherboard pad 31 is prepared on the side of the motherboard 3 near the display 1.

In a specific implementation, the motherboard pad 31 may be prepared simultaneously when preparing the first flexible circuit board 21 and the second flexible circuit board 22, or may be prepared when preparing the solder post 223, and the preparation time of the motherboard pad 3 is not limited, and only the motherboard pad 31 is required to be prepared at the corresponding position of the solder post 223.

S115: after the second flexible circuit board 22 is soldered to the first flexible circuit board 21, the middle frame 4 is assembled such that the middle frame 4 is used to fix the display screen 1, the first flexible circuit board 21, and the second flexible circuit board 22, wherein the solder post 223 is located at the opening of the middle frame 4.

S116: the main board 3 is buckled on the middle frame 4, the main board bonding pad 31 is heated by laser to melt the main board bonding pad 31, and under the extrusion action of the second flexible circuit board 22, the melted soldering tin of the main board bonding pad 31 flows from the welding column 223 to one side of the second flexible circuit board 22, which is away from the main board 3; after the solder is cured, the solder is connected with the solder post 223 to fix the second flexible circuit board 22 and the motherboard 3, and to realize electrical connection between the second flexible circuit board 22 and the motherboard 3.

It should be noted that, in the first to fifth flexible circuit board soldering methods in the above embodiments, the flexible circuit board soldering methods in the above embodiments have high utilization rate of the flexible circuit board, greatly reduce the manufacturing cost, and shorten the assembly period, but it should be noted that heat insulation and pressure control are required in the soldering process of the first pad 2121 and the second pad 2211, and the achieved soldering density is low.

Fig. 25 is a schematic diagram illustrating a sixth flowchart of a flexible circuit board soldering method according to an embodiment of the present application.

The method provided in the embodiment of the present application is specifically described below, and as shown in fig. 25, the method may further include the following steps:

S201: a first flexible circuit board 21 and a second flexible circuit board 22 are prepared.

In one implementation, the first flexible circuit board 21 and the second flexible circuit board 22 may be prepared in the manner of preparing the flexible circuit boards as shown in fig. 19. The first flexible circuit board 21 is manufactured into a convex shape, and the second flexible circuit board 22 is manufactured into a strip shape, so that a plurality of first flexible circuit boards 21 and second flexible circuit boards 22 are manufactured on the same flexible circuit board substrate, the substrate utilization rate is improved, and the manufacturing cost of the flexible circuit boards is greatly reduced.

S202: at least one first pad 2121 is prepared at the second end 212 of the first flexible circuit board 21 and at least one second pad 2211 is prepared at the third end 221 of the second flexible circuit board 22.

In one implementation, the second end 212 is disposed on a side of the convex protrusion away from the bottom of the display screen 1, and the second end 212 is provided with at least one first pad 2121, i.e., the first pad 2121 is prepared in the protrusion area.

In particular, the distribution manner and shape of the first bonding pads 2121 are the same as those of the step S102, and only the arrangement positions are different from those of the step S102, and the arrangement positions of the step S102 are arranged on the edge side of the second end 212 of the rectangular-like first flexible circuit board 21, and the first bonding pads 2121 are prepared in the convex portion area of the first flexible circuit board 21.

S203: the first end 211 of the first flexible circuit board 21 is soldered to the bottom edge of the display screen 1 so that the first flexible circuit board 21 is electrically connected to the bottom edge of the display screen 1.

In a specific implementation, step S203 is the same as the specific implementation of step S104. At this time, the display panel 1 is soldered to the first flexible circuit board 21 to form a combination.

S204: terminal 51 of BTB connector 5 is prepared on fourth end 222.

In a specific implementation, the terminal 51 may be prepared after the second flexible circuit board 22 is prepared, or may be prepared after the second pad 2211 is prepared.

S205: a seat 52 is prepared on the main board 3.

S206: the main board 3 is fastened to the middle frame 4 so that the terminals 51 are fastened to the base 52. At this time, the second flexible circuit board 22, the middle frame 4, and the main board 3 form a combination.

S207: the first bonding pad 2121 is extended from the first opening 41 of the middle frame 4, and the second bonding pad 2211 is extended from the second opening 42 of the middle frame 4, so that the first bonding pad 2121 and the second bonding pad 2211 are welded and connected with the second bonding pad 2211 on the surface of the middle frame 4 facing away from the first flexible circuit board 21. In a specific implementation, the welding mode is shown in fig. 26. Since the middle frame 4 can withstand temperature and pressure, the flexible circuit board welding method shown in this embodiment can achieve a higher welding density without heat insulation and without controlling pressure. It should be noted that, the shape of the middle frame 4 in the embodiment of the present application is only illustrative, and the opening area of the first opening 41 is larger in the design of part of the middle frame 4, and most of the area of the first flexible circuit board 21 may extend out of the middle frame 4, so that the first bonding pad 2121 and the second bonding pad 2211 can be more conveniently welded and connected on the middle frame 4.

Fig. 27 is a schematic diagram illustrating a seventh flow chart of a flexible circuit board soldering method according to an embodiment of the present application.

The method provided in the embodiment of the present application is specifically described below, and as shown in fig. 27, the method may further include the following steps:

s301: a first flexible circuit board 21 and a second flexible circuit board 22 are prepared.

In a specific implementation, the preparation method of the first flexible circuit board 21 and the second flexible circuit board 22 in step S301 is the same as the preparation method in step S201.

S302: at least one first pad 2121 is prepared at the second end 212 of the first flexible circuit board 21 and at least one second pad 2211 is prepared at the third end 221 of the second flexible circuit board 22.

In a specific implementation, the preparation method of the first pad 2121 and the second pad 2211 in step S302 is the same as the preparation method in step S202.

S303: the first flexible circuit board 21 and the second flexible circuit board 22 are solder-connected to the second pad 2211 through the first pad 2121.

In a specific implementation, the first flexible circuit board 21 and the second flexible circuit board 22 are welded and connected, and then the assembly formed by the first flexible circuit board 21 and the second flexible circuit board 22 is assembled with the display screen 1, and the assembly mode is the same as that of the integrated flexible circuit board 2.

S304: the first end 211 of the first flexible circuit board 21 is soldered to the bottom edge of the display screen 1 so that the first flexible circuit board 21 is electrically connected to the bottom edge of the display screen 1.

Compared with the integrated flexible circuit board 2, the technical scheme shown in the embodiment can improve the substrate utilization rate in the process of preparing the first flexible circuit board 21 and the second flexible circuit board 22 and greatly reduce the manufacturing cost of the flexible circuit board.

The embodiments of the present application include, but are not limited to, the first to seventh methods for soldering a flexible circuit board, and further include a method for soldering a flexible circuit board in which technical features in the foregoing embodiments are formed in one or more combinations, which is easy to understand that, based on several embodiments provided in the present application, a person skilled in the art may combine, split, reorganize, etc. the embodiments of the present application to obtain other embodiments, where all the embodiments do not exceed the protection scope of the present application.

The embodiment of the application provides a first electronic equipment disassembling process.

When the display screen is damaged such as screen pattern and crack, and the display screen needs to be replaced, for the display screen components welded in the first to fourth flexible circuit board welding methods as shown in the embodiments of the application, the following steps are often adopted to disassemble the machine:

S401: the display screen 1 is placed with its side facing away from the first flexible circuit board 21 facing downwards.

S402: and removing the electronic equipment shell, the battery and other devices.

S403: the main board 3 is detached from the center frame 4 to release the second sub-connector 52 from the first sub-connector 51.

S404: the middle frame 4 is removed.

S405: the display screen 1 and the first flexible circuit board 21 are replaced.

It should be noted that, in the disassembling process of the electronic device shown in the above embodiment, the middle frame needs to be disassembled, and the display screen 1 and the first flexible circuit board 21 need to be replaced, so that the assembly formed by the display screen 1 and the first flexible circuit board 21 as shown in the embodiment of the application can be installed in multiple models with different lengths of the second flexible circuit board 22, and the display screen 1 and the first flexible circuit board 21 can be normalized, so that the universality of the display screen assembly can be improved.

The second electronic equipment disassembling process provided by the embodiment of the application. When the display screen is damaged such as a screen pattern and a crack, and the display screen needs to be replaced, for a display screen assembly welded in the sixth flexible circuit board welding method shown in the embodiment of the application, the following steps are often adopted to disassemble the machine:

s501: the side of the housing facing away from the first flexible circuit board 21 is placed downwards.

S502: the welds of the first pad 2121 and the second pad 2211 are removed on the center 4 to obtain the separated display screen 1 and first flexible circuit board 21.

S503: the display screen 1 and the first flexible circuit board 21 are replaced.

It should be noted that, in the disassembling process of the electronic device shown in the above embodiment, the middle frame 4 is not required to be disassembled, and the display screen 1 and the first flexible circuit board 21 can be replaced, so that the disassembling process is simple.

It should be noted that the application includes, but is not limited to, welding for combining a soft board and a hard board, welding for combining a soft board and a soft board, welding a hard board and a hard board, welding a soft board and a hard board, and welding a soft board and a hard board.

The flexible circuit board welding method can solve the problems that the flexible circuit board used by the mobile phone display screen assembly at present is of an integrated convex structure, the convex structure leads to lower utilization rate of a substrate of the flexible circuit board, and a waste area is larger, so that waste of the substrate board is caused, and the manufacturing cost of the flexible circuit board is higher; meanwhile, the problem that the flexible circuit board of the integrated structure cannot be commonly used among display screen components of different specifications because the display screen components of electronic equipment of different models are different in specification can be solved. According to the technical scheme, the utilization rate of the substrate plate of the flexible circuit board can be improved in the manufacturing process of the flexible circuit board, the manufacturing cost of the flexible circuit board is greatly reduced, and the universality of the display screen assembly is improved. The foregoing detailed description of the embodiments of the present application has further described the objects, technical solutions and advantageous effects thereof, and it should be understood that the foregoing is merely a specific implementation of the embodiments of the present application, and is not intended to limit the scope of the embodiments of the present application, and any modifications, equivalent substitutions, improvements, etc. made on the basis of the technical solutions of the embodiments of the present application should be included in the scope of the embodiments of the present application.

Claims

1. A display screen assembly, comprising: the display screen, the substrate layer arranged on the back of the display screen, and the first flexible circuit board and the second flexible circuit board arranged on the back of the display screen;

the first flexible circuit board comprises a first end close to the bottom of the display screen and a second end far away from the bottom of the display screen; the first end is electrically connected with the bottom edge of the display screen, and the second end is provided with at least one first bonding pad;

the second flexible circuit board is of a strip-shaped structure and comprises a third end close to the first flexible circuit board and a fourth end far away from the first flexible circuit board along the length direction of the second flexible circuit board; the third end is provided with at least one second bonding pad; the third end is connected with the second bonding pad through the first bonding pad so as to be connected to the second end;

the substrate layer comprises a groove facing the first flexible circuit board, and the groove is positioned in a projection area of the first bonding pad on the substrate layer; the groove is used for filling heat insulation materials when the first bonding pad and the second bonding pad are welded;

the second bonding pad comprises a first bonding hole, and/or the first bonding pad comprises a second bonding hole; the first welding hole is a through hole positioned between the first surface of the second flexible circuit board and the second surface of the second welding disc, the first surface is the surface of the second flexible circuit board on the side opposite to the first flexible circuit board, the second surface is the surface of the second welding disc on the side close to the first flexible circuit board, and the first welding hole is used for injecting soldering tin; the second welding hole is a through hole positioned between a third surface of the first flexible circuit board and a fourth surface of the first welding disc, the third surface is a surface of the first flexible circuit board, which is opposite to one side of the second flexible circuit board, the fourth surface is a surface of the first welding disc, which is close to one side of the second flexible circuit board, and the second welding hole is used for injecting soldering tin;

The fourth end is configured to connect to a motherboard of an electronic device when the display screen assembly is mounted to the electronic device.

2. The display screen assembly of claim 1, wherein the display screen assembly comprises,

a first back adhesive is filled between the substrate layer and the first flexible circuit board, and the first back adhesive is coated in an annular mode around the heat insulation material; the first back adhesive is used for fixing the first flexible circuit board on the surface of the substrate layer, so that a gap for filling the heat insulation material is formed between the substrate layer and the first flexible circuit board.

3. The display screen assembly of claim 1, wherein the display screen assembly comprises,

a second back glue is filled between the first flexible circuit board and the second flexible circuit board, and the second back glue is coated on one side of the edge of the second end; the second back glue is used for fixing the first flexible circuit board and the second flexible circuit board.

4. The display screen assembly of claim 1, further comprising:

and the shielding layer is arranged on the surface of the second flexible circuit board, which is opposite to the display screen, and covers the second bonding pad.

5. The display screen assembly of claim 1, further comprising:

The fourth end is provided with a board-to-board connector for connection with a motherboard of the electronic device when the display screen assembly is mounted to the electronic device.

6. The display screen assembly of claim 1, further comprising:

when the display screen assembly is mounted on the electronic equipment, the fourth end is connected with a main board of the electronic equipment through FoB laser welding technology.

7. The display screen assembly of claim 1, wherein a length of the first end is greater than a length of the third end.

8. A method of soldering a flexible circuit board, applied to a display screen assembly as claimed in any one of claims 1 to 7, comprising:

preparing at least one first bonding pad at a second end of the first flexible circuit board, and preparing at least one second bonding pad at a third end of the second flexible circuit board; the second bonding pad is provided with a first bonding hole, and/or the first bonding pad is provided with a second bonding hole; the first welding hole is a through hole positioned between the first surface of the second flexible circuit board and the second surface of the second welding disc, the first surface is the surface of the second flexible circuit board on the side opposite to the first flexible circuit board, the second surface is the surface of the second welding disc on the side close to the first flexible circuit board, and the first welding hole is used for injecting soldering tin; the second welding hole is a through hole positioned between a third surface of the first flexible circuit board and a fourth surface of the first welding disc, the third surface is a surface of the first flexible circuit board, which is opposite to one side of the second flexible circuit board, the fourth surface is a surface of the first welding disc, which is close to one side of the second flexible circuit board, and the second welding hole is used for injecting soldering tin;

Preparing a groove facing the first flexible circuit board on a substrate layer of a display screen, wherein the groove is positioned in a projection area of the first bonding pad on the substrate layer;

and welding the first flexible circuit board and the second flexible circuit board with the second bonding pad through the first bonding pad, wherein in the welding connection process, a heat insulation material is filled in the groove.

9. The method for soldering a flexible circuit board according to claim 8, wherein,

further comprises:

and welding the first end of the first flexible circuit board to the bottom edge of the display screen so that the first flexible circuit board is electrically connected with the bottom edge of the display screen.

10. The flexible circuit board soldering method according to claim 9, further comprising:

the insulating material is removed when the second flexible circuit board has been soldered to the first flexible circuit board.

11. The flexible circuit board soldering method according to claim 10, further comprising:

filling a first back adhesive between the substrate layer and the first flexible circuit board, wherein the first back adhesive is coated in an annular mode around the heat insulation material; the first back adhesive is used for fixing the first flexible circuit board on the surface of the substrate layer, so that a gap for filling the heat insulation material is formed between the substrate layer and the first flexible circuit board.

12. The flexible circuit board soldering method according to claim 10, further comprising:

filling second back glue between the first flexible circuit board and the second flexible circuit board, wherein the second back glue is positioned at the edge of the second end of the first flexible circuit board; the second back glue is used for fixing the first flexible circuit board and the second flexible circuit board.

13. The flexible circuit board soldering method according to claim 9, further comprising:

preparing the first flexible circuit board into a convex shape, wherein the at least one first bonding pad is positioned at the protruding part of the convex shape;

and the first bonding pad extends out of the first opening of the middle frame, and the second bonding pad extends out of the second opening of the middle frame, so that the first bonding pad and the second bonding pad are welded and connected with the second bonding pad on the surface, facing away from the first flexible circuit board, of the middle frame, and the middle frame is positioned on one side, facing away from the display screen, of the first flexible circuit board.

14. The method for soldering a flexible circuit board according to any one of claims 8 to 13, wherein,

the first flexible circuit board and the second flexible circuit board are connected with the second bonding pad through the first bonding pad in a welding way, and the method further comprises the following steps:

And the fourth end of the second flexible circuit board is buckled with the main board of the electronic equipment through a board-to-board connector.

15. The method for soldering a flexible circuit board according to any one of claims 8 to 13, wherein,

before the first flexible circuit board and the second flexible circuit board are connected with the second bonding pad through the first bonding pad, the method further comprises:

and welding the fourth end of the second flexible circuit board with a main board of the electronic equipment through a FoB welding technology.

16. The flexible circuit board welding method according to claim 14 or 15, further comprising:

and preparing a shielding layer on the surface of the second flexible circuit board, which is opposite to the display screen, and covering the second bonding pad by the shielding layer.

17. The method of soldering a flexible circuit board according to claim 16, wherein the manner of soldering the first pad and the second pad further comprises: laser welding and thermocompression welding.