CN115550484A

CN115550484A - Display screen assembly and flexible circuit board welding method

Info

Publication number: CN115550484A
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: 2022-12-30
Anticipated expiration: 2042-03-31
Also published as: CN115550484B

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 edge of the bottom 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 terminal is for connection to 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 plate 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 indispensable parts that can group together and provide electrical connections for a large number of electrical components. The flexible circuit board is one kind of circuit board, is one kind of printed circuit board with high reliability and excellent flexibility and is made of polyimide or polyester film as base material and has the features of high wiring density, light weight, thin thickness and high bending performance.

In the process of manufacturing a flexible circuit board, the existing manufacturing method generally includes: 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, an integral cutting is performed along the edge of each flexible circuit board to be cut, and an excess portion is etched away to obtain a plurality of independent flexible circuit boards.

At present, a flexible circuit board used by a mobile phone display screen assembly is generally of an integrated convex structure, the utilization rate of a substrate of the flexible circuit board is low due to the convex structure, and a waste area is large, so that the waste of the substrate plate is caused, and the manufacturing cost of the flexible circuit board is high. In addition, because the display screen assemblies of different models of electronic devices have different specifications, the flexible circuit board with an integrated structure cannot be used universally among the display screen assemblies with 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 a flexible circuit board and improve 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, an embodiment of the present application provides 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 edge of the bottom 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 terminal is for connection to 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 in a split structure, so that the utilization rate of the substrate plate 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 edge of the bottom of the display screen, the display screen and the first flexible circuit board can be normalized to be suitable for connecting second flexible circuit boards with various lengths, the display screen component is convenient to apply to electronic equipment with different models, and the universality of the display screen component 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 welding 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 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 mode, a first back adhesive is filled between the substrate layer and the first flexible circuit board, and the first back adhesive is coated around the heat insulation material in an annular mode; the first back glue 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. With this embodiment, the gap between the substrate layer and the first flexible circuit board can be filled with the first adhesive, and the gap between the substrate layer and the first flexible circuit board can be made more firm.

In one implementation mode, 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; the second gum 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: and the shielding layer is arranged on the surface of the second flexible circuit board back to the display screen and covers the second bonding pad. By adopting the embodiment, the interference of the welding position of the first bonding pad and the second bonding pad on other devices can be avoided.

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

In one implementation, when the display screen assembly is mounted to an electronic device, the fourth terminal is connected to a motherboard of the electronic device via a FoB laser welding technique. By adopting the embodiment, the second flexible circuit board can be connected with the mainboard in a FoB welding mode, so that a more stable connection effect is achieved between the second flexible circuit board and the mainboard.

In one implementation, the length of the first end is greater than the length of the third end. By adopting the embodiment, the shape relationship between the first flexible circuit board and the second flexible circuit board is limited, the first flexible circuit board can be of a similar rectangular structure, the second flexible circuit board can be of a strip structure, or the first flexible circuit board can be of a convex structure, and the second flexible circuit board can be of a strip 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, applied to the display screen assembly shown in the first aspect and various implementation manners of the first aspect, including: 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 and connecting the first flexible circuit board and the second flexible circuit board through the first welding disc and the second welding disc. By adopting the embodiment, the first flexible circuit board and the second flexible circuit board are prepared into the split structure, so that a plurality of first flexible circuit boards and a plurality of 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 method for connecting a first flexible circuit board to a second flexible circuit board by soldering via a first pad and a second pad further includes: and welding the first end of the first flexible circuit board to the bottom edge of the display screen so as to electrically connect the first flexible circuit board with the bottom edge of the display screen. By adopting the embodiment, the first flexible circuit board is firstly welded to the edge of the bottom 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 mode, a groove facing the first flexible circuit board is prepared on a substrate layer of the display screen, and the groove is located in a projection area of the first bonding pad on the substrate layer; when the first flexible circuit board and the second flexible circuit board are connected through the first welding disc and the second welding disc in a welding mode, heat insulation materials are filled in the grooves 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, on the basis of realizing the normalization of the first flexible circuit board and the display screen, the problem of influence on the display screen caused by welding the second flexible circuit board is solved.

In one implementation, a first back adhesive is filled between the substrate layer and the first flexible circuit board, and is coated in a ring shape around the heat insulation material; the first back glue 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. With this embodiment, the gap between the substrate layer and the first flexible circuit board can be filled with the first adhesive, and the gap between the substrate layer and the first flexible circuit board can be made more firm.

In one implementation mode, second gum is filled between the first flexible circuit board and the second flexible circuit board, and the second gum 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 mode, the first flexible circuit board is made into a convex shape, at least one first pad is located on a convex portion of the convex shape, the first pad extends out from a first opening of the middle frame, and the second pad extends out from a second opening of the middle frame, so that the first pad and the second pad are connected with the second pad in a welding mode on the surface of the middle frame, back to the first flexible circuit board, wherein the middle frame is located on the side, back to 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 a split structure, and a plurality of first flexible circuit boards and a plurality of second flexible circuit boards can be cut from the same flexible circuit board substrate, so that the utilization rate of the substrate is improved, and the manufacturing cost of the flexible circuit boards is greatly reduced.

In one implementation, the solder connecting the first flexible circuit board and the second flexible circuit board by the first pad and the second pad further includes: and fastening the fourth end of the second flexible circuit board with the mainboard of the electronic equipment through a board-to-board connector. By adopting the embodiment, the second flexible circuit board can be connected with the mainboard through the board-to-board connector, so that the second flexible circuit board and the mainboard can be detached from each other.

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

In one implementation, a shielding layer is prepared on the surface of the second flexible circuit board opposite to the display screen, and the shielding layer covers the second bonding pad. By adopting the embodiment, the interference of the welding position of the first bonding pad and the second bonding pad on other devices can be avoided.

In one implementation, a bonding manner of a first pad and a second pad includes: laser welding and/or heat press 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 requirements.

The technical scheme can solve the problems that the flexible circuit board used by the current mobile phone display screen assembly is generally of an integrated convex structure, the utilization rate of the substrate of the flexible circuit board is low due to the convex structure, the waste area is large, the substrate plate is wasted, and the manufacturing cost of the flexible circuit board is high; meanwhile, the problem that the flexible circuit board with the integrated structure cannot be universal among display screen assemblies with different specifications due to different specifications of the display screen assemblies of electronic equipment with different models 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 is an exploded view illustrating an internal structure of an electronic device;

FIG. 2 illustrates a schematic diagram of different types of flexible circuit boards;

FIG. 3 is a schematic diagram illustrating an exemplary flexible circuit board manufacturing process;

FIG. 4 is a schematic diagram illustrating a connection manner between a motherboard and a flexible circuit board;

FIG. 5 is a schematic diagram illustrating another connection of a motherboard to a flexible circuit board;

FIG. 6 is a schematic view illustrating a display screen replacement method;

FIG. 7 illustrates a display screen assembly schematic;

FIG. 8 illustrates a first flexible circuit board structure;

FIG. 9 is a schematic diagram illustrating a first pad distribution pattern;

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 is a schematic diagram illustrating an exemplary flexible circuit board fabrication;

FIG. 13 is a schematic view illustrating a groove shape;

FIG. 14 schematically illustrates a groove shape;

FIG. 15 is a schematic diagram illustrating an exemplary display screen assembly;

FIG. 16 is a schematic view illustrating an exemplary display screen assembly;

FIG. 17 is a schematic view illustrating an exemplary display screen assembly configuration;

FIG. 18 is a schematic view illustrating a display screen assembly;

FIG. 19 is a schematic view illustrating a display screen assembly structure;

FIG. 20 is a schematic flow chart diagram illustrating a flexible circuit board soldering method;

FIG. 21 is a flow chart illustrating a flexible circuit board soldering method;

FIG. 22 is a schematic flow chart diagram illustrating a flexible circuit board soldering method;

FIG. 23 is a schematic flow chart diagram illustrating a flexible circuit board soldering method;

FIG. 24 is a schematic flow chart diagram illustrating a flexible circuit board soldering method;

FIG. 25 is a schematic flow chart diagram illustrating a flexible circuit board soldering method;

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

fig. 27 schematically shows 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 this application, "/" means "or" unless otherwise stated, for example, A/B may mean A or B. "and/or" herein is merely an association describing an associated object, and means that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. Further, "at least one" means one or more, "a plurality" means two or more. The terms "first," "second," and the like do not denote any order or importance, but rather the terms "first," "second," and the like do not denote any order or importance.

It is noted that, in the present application, words such as "exemplary" or "for example" are used to mean exemplary, illustrative, or descriptive. Any embodiment or design described herein as "exemplary" or "such as" is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present concepts related in a concrete fashion.

In order to facilitate the technical solutions of the embodiments of the present application to be understood by the skilled person, the technical terms related to the embodiments of the present application are explained below.

1. A Flexible Printed Circuit (FPC), which is a Printed Circuit board made of polyimide or polyester film as a base material and has high reliability and excellent flexibility, and has the characteristics of high wiring density, light weight, thin thickness and good bending property.

2. An Anisotropic Conductive Film (ACF) comprises a resin adhesive and Conductive particles, and is characterized in that the vertical direction of the ACF is a Conductive ventilation direction, the horizontal plane is an insulating plane, the ACF has a resistance characteristic, the characteristics of the vertical direction and 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 electrodes, and meanwhile, the conduction short circuit between two adjacent electrodes can be avoided, so that the purpose of conducting only in the vertical direction is achieved.

3. The Board is To Board connector (Board To Board, BTB), can be used To connect flexible circuit Board and mainboard, has that the transmission ability is strong, frivolous, high frequency transmission is stable, need not the characteristics that welding, fall make an uproar.

4. A flexible Board and hard Board bonding (FPC on Board, foB) soldering technique is a soldering technique that can be used to solder a flexible circuit Board and a main Board. The technical process comprises the following steps: heating a bonding pad on the mainboard through laser to melt the bonding pad; under the extrusion action of the flexible circuit board, enabling the soldering tin melted by the soldering pad to flow from the soldering copper of the flexible circuit board to one side of the flexible circuit board back to the mainboard; after the soldering tin is solidified, the soldering tin is connected with the soldering copper so as to fix the flexible circuit board and the mainboard, and the electrical connection of the flexible circuit board and the mainboard is realized.

Fig. 1 is an exploded view illustrating an internal structure of an electronic device. As shown in fig. 1, the electronic device may include: display screen 1, flexible circuit board 2, mainboard 3 and center 4. The display screen 1 back that flexible circuit board 2 set up in, center 4 sets up in one side of flexible circuit board 2 back to display screen 1 for fixed display screen 1 and flexible circuit board 2, mainboard 3 set up in one side of center 4 back to display screen 1, and mainboard 3 is connected with flexible circuit board 2 electricity at the opening part of center 4.

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

Fig. 2 illustrates a schematic diagram 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 shape of a Chinese character 'tu', and may include a main body portion 2-1 in a shape of a rectangle and a protruding portion 2-2 in a shape of a strip, where the main body portion 2-1 and the protruding portion 2-2 are an integral structure. The long side of one side of the main body 2-1 is generally connected to the bottom edge of the display screen 1 by welding, the long side of the other side is connected to the short side of one side of the protruding part 2-2, and the short side of the other side of the protruding part 2-2 extends in a direction away from the main body 2-1 and is finally connected to the main board 3 of the electronic device, where 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. Generally, the farther the distance between the main board 3 and the bottom of the display screen 1, the longer the length of the protruding 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 different electronic devices have different sizes and different internal layouts, the length of the protruding portion 2-2 of the flexible circuit board 2 in different electronic devices is greatly different, and therefore, the flexible circuit board 2 with the same size is difficult to adapt to electronic devices with different models.

Fig. 3 schematically illustrates a flexible circuit board manufacturing method. As shown in fig. 3, in the process of manufacturing the flexible circuit board 2, the existing 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, an integral cutting is performed along the edge of each flexible circuit board 2 to be cut, and an excess portion is etched away to obtain a plurality of individual flexible circuit boards 2. At present, the flexible circuit board 2 used by the mobile phone display screen assembly is generally an integrated convex structure, the utilization rate of the substrate is low due to the convex structure, and the waste area is large, so that the waste of the substrate plate is caused, and the manufacturing cost of the flexible circuit board is high.

Fig. 4 is a schematic diagram illustrating a connection manner between a motherboard and a flexible circuit board. As shown in fig. 4, a 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, a surface of the main board 3 facing the display screen 1 is provided with a seat 52 of the BTB connector 5, and the terminal 51 and the seat 52 are fastened at an opening of the middle frame 4.

In the foregoing embodiment, the long side of the main body 2-1 is generally connected to the bottom edge of the display screen 1 by ACF welding, and the flexible circuit board 2 is an integrated structure, so that when the terminal 51 and the seat 52 are fastened at the opening of the middle frame 4, the assembled display screen 1 and flexible circuit board 2 are fastened to the assembled middle frame 4 and main board 3, or the assembled display screen 1 and flexible circuit board 2 are assembled to the middle frame 4 and then fastened to the main board 3. When the display screen 1 is damaged, the main board 3 and the middle frame 4 need to be detached to integrally replace the display screen 1 and the flexible circuit board 2.

Fig. 5 is a schematic diagram illustrating another connection manner between the main board and the flexible circuit board. As shown in fig. 5, a main board pad 31 is disposed on the surface of the main board 3 close to the display screen 1, a hollow welding column 223 is disposed on the surface of the short side of one side of the protruding portion 2-2 opposite to the display screen 1, and the main board pad 31 can be melted by laser through the FoB laser welding technology, specifically, the main board pad 31 on the main board 3 is heated by laser to melt the main board pad 31; under the squeezing action of the flexible circuit board 2, the soldering tin melted on the main board pad 31 flows from the soldering column 223 to the side of the flexible circuit board 2 back to the main board 3; after the soldering tin is solidified, the soldering tin is connected with the soldering posts 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 between the flexible circuit board 2 and the main board 3. When the display screen of the electronic device is damaged, because the long edge of one side of the main body part 2-1 is welded and connected with the edge of the bottom of the display screen 1 through the ACF, and the short edge 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, not only the display screen 1 and the flexible circuit board 2 need to be integrally replaced, but also the short edge of one side of the protruding part 2-2 needs to be separated from the welded part of the main board 3, and the disassembly difficulty is high.

Fig. 6 is a schematic diagram illustrating an exemplary display screen replacement method. As shown in fig. 6, taking the connection mode of the main board 3 and the flexible circuit board 2 as BTB connection as an example, the terminal 51 and the seat 52 are fastened at the connection point a, and when the display screen is replaced, only the display screen 1 connected with the flexible circuit board 2 of the same model 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 seat 52 at the connection point a. If the display screen 1 connected with the flexible circuit boards 2 of different models is replaced, the lengths of the convex parts 2-2 of the flexible circuit boards 2 are different, and the terminal 51 of the short edge at one side of the convex part 2-2 cannot be buckled with the seat body 52, so that the problem that the display screen 1 connected with the flexible circuit boards 2 of different models cannot be universal in the existing display screen replacing process exists.

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

Fig. 7 schematically illustrates a first schematic diagram of a structure of a display screen assembly provided by an embodiment of the present application. As shown in fig. 7, the display screen assembly includes: the display device comprises a display screen 1, and a first flexible circuit board 21 and a second flexible circuit board 22 which are arranged on the back of the display screen 1. It should be noted that the first flexible circuit board 21 and the second flexible circuit board 22 in the embodiment of the present application are separate structures.

Wherein, the first flexible circuit board 21 includes a first end 211 close to 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 is 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; the third end 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 as a rectangular-like structure as shown in fig. 8, and the first end 211 may be fixed on 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 on the back of the display panel 1 by means of ACF soldering, and conductive particles in the ACF can electrically connect the first end 211 with the display panel 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 arranged in a staggered distribution manner or a side-by-side distribution manner as shown in fig. 9 to reduce the pressure during soldering in a suitable distribution manner. 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 first pads 2121 of different shapes have different bonding capabilities during bonding, and the shape of the first pads 2121 can be designed according to actual conditions. 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 arranged corresponding to the shape of the first pad 2121 so that the first pad 2121 is tightly welded with the second pad 2211. It should be noted that at least one first solder hole 2212 is further disposed on the second flexible circuit board 22, 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, which faces away from the first flexible circuit board 21, to a surface of the second solder pad 2211, which is close to the first flexible circuit board 21. During the soldering process, solder is injected from the first solder hole 2212, and the solder is melted to solder the first solder pad 2121 and the second solder pad 2211.

Fig. 11 is a schematic diagram illustrating a cross-sectional structure of a display screen assembly. As shown in fig. 11, after the first pad 2121 and the second pad 2211 are tightly welded, the thicknesses of the first pad 2121 and the second pad 2211, the thicknesses of the solders used for welding the first pad 2121 and the second pad 2211, and the maximum thickness of the second flexible circuit board 22 are not more than 0.25 mm, so that the thickness of the flexible circuit board including the welding structure shown in the present 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. It should be noted that, during the process of welding the first pad and the second pad, solder needs to be injected from at least one first welding hole 2212, so that the solder flows out from the surface of the first welding hole 2212 facing the first pad 2121, and the first pad 2121 is welded to the second pad 2211, the actual setting of the welding position of the first pad 2121 and the second pad 2211 further includes the solder thickness, the solder thickness is determined according to the actually adopted solder material, the solder time, and the solder temperature, the solder thickness is not shown in the schematic cross-sectional structure diagram and the schematic cross-sectional structure diagram described below, and the consideration needs to be given in the actual setting.

In the present application, the actual arrangement manner of the first pad 2121, the second pad 2211 and the first welding hole 2212 includes, but is not limited to, the embodiments shown in the examples and the drawings of the present application, and in the specific arrangement, an arrangement manner may also be adopted in which the first welding hole 2212 is not arranged on the second pad 2211, the surface of one side of the second pad 2211 facing the display screen is provided with a pre-soldering tin, and the second pad 2211 is connected with the first pad 2121 through thermocompression bonding; 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 side, facing the display screen, of the second bonding pad 2211 is provided with the pre-soldering tin, and the second bonding pad 2211 and the first bonding pad 2121 are welded through hot-pressing, so that the pre-soldering tin flows into the second bonding hole, and the second bonding pad 2211 and the first bonding pad 2121 are connected in a welding mode. It should be noted that in the present application, a single-sided arrangement of the solder holes, a double-sided arrangement of the solder holes, and no solder holes may be adopted, and the arrangement of the solder holes, the distribution of the solder holes, and the shapes of the solder holes may affect the welding density of the first solder pad 2121 and the second solder pad 2211 in the welding process. In some embodiments, the shape of the first welding hole 2212 and the second welding hole may be at least one of circular, slotted, peanut-shaped, and semicircular, and the embodiments of the present application do not limit the shape, number, and the like of the first welding hole 2212 and the second welding hole.

Fig. 12 schematically illustrates a preparation method of a flexible circuit board provided by 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 provided in the embodiment of the present application are in a split structure, the first flexible circuit board 21 may be configured as a quasi-rectangular shape, and the second flexible circuit board 22 may be configured as a strip shape, which are both in a more regular shape, compared with the convex-shaped flexible circuit board 2 in the conventional integrated structure, the embodiment of the present application shows that the preparation method can perform layout more flexibly on the flexible circuit board substrate plate. In a specific implementation, the first flexible circuit board 21 may be intensively arranged in one region of the flexible circuit board substrate plate, and the second flexible circuit board 22 may be intensively arranged in another region; or the first flexible circuit board 21 and the second flexible circuit board 22 are arranged on the flexible circuit board substrate plate in a mixed mode; or the first flexible circuit board 21 is intensively arranged in the central area of the flexible circuit board substrate plate, and the second flexible circuit board 22 is arranged in the edge area. The specific layout mode 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 convex flexible circuit board 2 of the traditional integrated structure shown in fig. 3, the layout mode of the first flexible circuit board 21 and the second flexible circuit board 22 shown in the embodiment of the application can improve the utilization rate of the substrate by more than 33.3%, and greatly reduce the manufacturing cost of the flexible circuit board.

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, high temperature is generated during the soldering process of the first bonding pad 2121 and the second bonding pad 2211. Therefore, in order to ensure that the bonding process of the first pads 2121 and the second pads 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.

Generally, the display panel 1 is provided with a substrate layer 11 and an organic material layer 12 on the back side, and the substrate layer 11 may be a metal material, such as: copper, steel, aluminum, etc., which are not limited in the examples of the present application. In this embodiment, the groove 111 may be disposed on a side of the substrate layer 11 facing the first flexible circuit board 21, the groove 111 is located in a projection area of the first pad 2121 on the substrate layer 11, and the groove 111 is used for filling the insulation material 8 during the first pad 2121 and the second soldering 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, where the closed square groove and the closed circular groove are grooves that are not communicated with each other and have a certain distance between the wall surface of the groove 111 and the edge of the substrate layer 11; or a through-type square groove as shown in fig. 14, wherein the through-type groove is a groove in which the groove 111 communicates with the edge of the substrate layer 11.

The display panel 1 in the embodiment of the present application may be an Organic Light-Emitting Diode (OLED) display panel. The basic structure of the OLED display screen comprises: indium Tin Oxide (ITO) glass, a layer of organic light-emitting material with the thickness of tens of nanometers on the ITO glass, and a metal electrode with low work function. Here, 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 for welding the tin paste SnBiAg at low temperature is 180-220 ℃; are far beyond the temperature resistance of the display screen 1. Therefore, in the embodiment of the present application, when the first pad 2121 and the second pad 2211 are welded, the heat insulating material 8 may be added at a position 0.1 mm to 0.3mm outside the welding position of the first pad 2121 and the second pad 2211, and the heat insulating material 8 may isolate the influence of the high temperature generated by the welding on the display screen 1. In the embodiment of the present application, the distance between the bottom of the groove 111 and the first flexible circuit board is preferably not greater than 0.3mm, and therefore, the thickness of the heat insulating material 8 is also preferably not greater 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 opposite to the display screen 1, and covers the second pad 2211. Since the first bonding pad 2121 and the second bonding pad 2211 are made of metal, the bonding position of the first bonding pad 2121 and the second bonding pad 2211 may interfere with other devices in the electronic apparatus during use of the electronic apparatus, and the shielding layer 6 is used to prevent the bonding position of the first bonding pad 2121 and the second bonding pad 2211 from interfering with other devices in the electronic apparatus.

It should be noted that, in the prior art, the back of the display screen 1 and the surface of the flexible circuit board 2 near the display screen 1 side are often provided with an anti-interference shielding layer for preventing the interference between other devices of the electronic device and the display screen 1 and the flexible circuit board 2, in this embodiment of the application, a shielding layer is also provided between the back of the display screen 1 and one side of the first flexible circuit board 21 and one side of the second flexible circuit board 22 near the back of the display screen 1 for anti-interference, because the setting of the anti-interference shielding layer is the same as that in the prior art, no further description is provided here, and therefore, only the newly added shielding layer 6 is described, that is, the shielding layer 6 shown in fig. 13.

Fig. 15 is a second schematic diagram illustrating a structure of a display screen assembly provided by an embodiment of the application. As shown in fig. 15, in one implementation, in order to better protect the display screen during the soldering of the first pad 2121 and the second pad 2211, the display screen assembly may further include: a first back adhesive 71; the first adhesive tape 71 is filled between the substrate layer 11 and the first flexible circuit board 21, the first adhesive tape 71 is annularly coated around the heat insulating material 8, and the first adhesive tape 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 heat insulating material 8 is filled in the groove 111, 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, the thickness of the substrate layer 11 needs to be increased, resulting in an excessively high cost of the substrate layer 11. The embodiment of the application increases the distance between the substrate layer 11 and the first flexible circuit board 21 by filling the first back adhesive 71 between the substrate layer 11 and the first flexible circuit board 21, and the increased distance can be used for accommodating the first back adhesive 71 with larger thickness, so that the thickness of the heat insulating material 8 is ensured without increasing the thickness of the substrate layer 11.

Note that, when the groove 111 is a closed square groove as shown in fig. 13 or a closed circular groove, the heat insulating material 8 is disposed in conformity with the shape of the groove 111, the first adhesive tape 71 is applied in a ring shape around the heat insulating material 8, and when the groove 111 is a through square groove as shown in fig. 14, the first adhesive tape 71 is applied on the closed side of the through square groove.

Fig. 16 schematically illustrates a third structural diagram of a display screen assembly provided by an embodiment of the present application. As shown in fig. 16, in one implementation manner, in order to ensure the stability of the second flexible circuit board 22 after the first flexible circuit board 21 is soldered to the second flexible circuit board 22, the display screen assembly may further include: a second adhesive backing 72; the second adhesive 72 is filled between the first flexible circuit board 21 and the second flexible circuit board 22, and the second adhesive 72 is located at the edge of the second end 212, and the second adhesive 72 is used to fix the first flexible circuit board 21 and the second flexible circuit board 22.

Fig. 17 schematically shows a fourth schematic diagram of the structure of the display screen assembly provided by the 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, and when the display panel assembly is mounted on the electronic device, the terminal 51 is connected with a seat 52 provided on the main board 3.

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

Fig. 18 is a fifth schematic view illustrating a structure of a display screen assembly provided by an embodiment of the present application. In one implementation, fourth end 222 is connected to motherboard 3 by a FoB laser welding technique, as shown in fig. 18. In a specific implementation, the main board pad 31 is heated by laser to melt the main board pad 31, and under the squeezing action of the second flexible circuit board 22, the melted soldering tin of the main board pad 31 flows from the soldering post 223 to one side of the second flexible circuit board 22 opposite to the main board 3; after the solder is solidified, the solder is connected to the solder post 223 to fix the second flexible circuit board 22 and the motherboard 3, so as to electrically connect the second flexible circuit board 22 and the motherboard 3.

It should be noted that the motherboard bonding pad 31 and the soldering post 223 are located at the opening of the middle frame 4, so that the motherboard 3, the middle frame 4 and the fourth end 222 can be soldered together after the motherboard bonding pad 31 is melted and re-solidified.

Fig. 19 is a sixth schematic view schematically illustrating a structure of a display screen assembly provided by an embodiment of the present application. As shown in fig. 19, the first flexible circuit board 21 may be configured as 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 protrusion 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 bar-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, 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 the display screen assembly formed by forming one or more combinations of the technical features of the embodiments described above, and it is easily understood that, on the basis of the several embodiments provided in the present application, a person skilled in the art may combine, split, recombine, etc. the embodiments of the present application to obtain other embodiments, and these embodiments do not exceed the protection scope of the present application.

In some embodiments, the display screen assembly provided by the embodiments of the present application can be used in an electronic device. The electronic device in the embodiment of the present application may be, for example, a mobile terminal or a fixed terminal having a touch screen, such as a tablet computer (PAD), a Personal Digital Assistant (PDA), a handheld device having a wireless communication function, a computing device, a vehicle-mounted device or a wearable device, a Virtual Reality (VR) terminal device, an Augmented Reality (AR) terminal device, a wireless terminal in industrial control (industrial control), a wireless terminal in unmanned driving (self driving), a wireless terminal in remote medical (remote medical), a wireless terminal in smart grid, a wireless terminal in transportation security, a wireless terminal in smart city (smart city), a wireless terminal in smart home (smart home), and the like. The electronic device according to the present application can be mounted on

Harmony

Or other operating system, which is not limited in this application.

The display screen assembly can solve the problems that the flexible circuit board used by the existing mobile phone display screen assembly is generally of an integrated convex structure, the utilization rate of the substrate of the flexible circuit board is low due to the convex structure, the waste area is large, the substrate plate is wasted, and the manufacturing cost of the flexible circuit board is high; meanwhile, the problem that the flexible circuit board with the integrated structure cannot be universal among display screen assemblies with different specifications due to different specifications of the display screen assemblies of electronic equipment with different models 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 the flexible circuit board welding process of electronic equipment, in particular to the electronic equipment with a display screen assembly. The soldering method for the flexible circuit board provided by the embodiment of the application can be used for preparing the display screen assembly in the embodiment shown in the figures 7 to 19 and the display screen assembly formed by one or more combinations in the embodiment shown in the figures 7 to 19.

Fig. 20 schematically illustrates a first flowchart of a flexible circuit board soldering method provided by an embodiment of the present application.

As shown in fig. 20, the method provided in the embodiment of the present application 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 the embodiment of this application are the components of a whole that can function independently structure, and first flexible circuit board 21 can be prepared to the similar rectangle, and second flexible circuit board 22 can be prepared to the bar, is more regular shape, consequently in the convex character form flexible circuit board 2 of traditional integral structure, can be more nimble on flexible circuit board base plate material carry out the overall arrangement. In a specific implementation, the first flexible circuit board 21 may be intensively arranged in one region of the flexible circuit board substrate plate, and the second flexible circuit board 22 may be intensively arranged in another region; or the first flexible circuit board 21 and the second flexible circuit board 22 are arranged on the flexible circuit board substrate plate in a mixed mode; or the first flexible circuit board 21 is intensively arranged in the central area of the flexible circuit board substrate material, and the second flexible circuit board 22 is arranged in the edge area. The specific layout mode 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 convex flexible circuit board 2 of the traditional integrated structure shown in fig. 3, the layout mode of the first flexible circuit board 21 and the second flexible circuit board 22 shown in the embodiment of the application can improve the utilization rate of the substrate by more than 33.3%, and greatly reduce the manufacturing cost of the flexible circuit board.

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.

Among them, the first pads 2121 may be prepared in a staggered distribution manner or a parallel distribution manner as shown in fig. 9, so as to reduce the pressure during soldering by a suitable distribution manner. The first pad 2121 may be prepared in at least one shape of a circle, a groove, and a peanut shape as shown in fig. 10. The first pads 2121 of different shapes have different bonding capabilities during bonding, and the shape of the first pads 2121 can be designed according to actual conditions. Wherein the second pad 2211 is prepared corresponding to the shape of the first pad 2121 so that the first pad 2121 and the second pad 2211 are tightly welded.

The manner of bonding the first pad 2121 and the second pad 2211 includes: laser welding and/or heat press welding. In a specific implementation, the laser welding may be an efficient precision welding method using a laser beam with high energy density as a heat source, that is, the laser radiation heats the surface of the second pad 2211, so that the second pad 2211 is melted and tightly welded to the first pad 2121. The thermocompression bonding is to generate plastic deformation of the first bonding pad 2121 and the second bonding pad 2211 by heating and pressurizing, and simultaneously destroy an oxide layer on a bonding interface, so that the range of atomic attraction between the bonded first bonding pad 2121 and the bonded second bonding pad 2211 is reached, and the atoms generate attraction force to achieve the purpose of bonding.

S103: preparing a groove 111 facing the first flexible circuit board 21 on a substrate layer 11 of the display screen 1, wherein the groove 111 is located in a projection area of the first pad 2121 on the substrate layer 11; the groove 111 is filled with an 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 a closed circular groove, wherein the closed square groove and the closed circular groove are grooves in which the wall surface of the groove 111 has a certain distance with the edge of the substrate layer 11 and are not communicated; or a through-type square groove as shown in fig. 14, wherein the through-type groove is a groove in which the groove 111 communicates with the edge of the substrate layer 11. When the first bonding pad 2121 and the second bonding pad 2211 are welded on the back of the display screen, the welding temperature of the high-temperature welding tin paste SAC305 is 260-280 ℃; the welding temperature for welding the tin paste SnBiAg at low temperature is 180-220 ℃; are far beyond the temperature resistance of the display screen 1. Therefore, in the embodiment of the present application, when the first pad 2121 and the second pad 2211 are welded, the heat insulating material 8 may be added at a position 0.1 mm to 0.3mm outside the welding position of the first pad 2121 and the second pad 2211, and the heat insulating material 8 may isolate the influence of the high temperature generated by the welding on the display screen 1. In the embodiment of the present application, the distance between the bottom of the groove 111 and the first flexible circuit board is preferably not greater than 0.3mm, and therefore, the thickness of the heat insulating material 8 is also preferably not greater 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 of the display panel 1 by means of ACF soldering, and the conductive particles in the ACF may electrically connect the first end 211 to the display panel 1. It should be noted that the embodiments of the present application include, but are not limited to, an ACF soldering method, and other soldering methods, pressure bonding methods, and adhesion methods may be used.

S105: the first flexible circuit board 21 and the second flexible circuit board 22 are soldered to the second solder pad 2211 via the first solder pad 2121, and the heat 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 panel 1 and the first and second

flexible circuit boards

21 and 22 is affected.

S106: a shielding layer 6 is prepared on the surface of the second flexible circuit board 22 opposite to the display screen 1, and the shielding layer 6 covers the second bonding pad 2211. Since the first pad 2121 and the second pad 2211 are made of metal, the soldered portion may interfere with other devices in the electronic apparatus during use, and therefore, the shielding layer 6 is used to prevent the soldered portion of the first pad 2121 and the second pad 2211 from interfering with other devices in the electronic apparatus.

Fig. 21 schematically illustrates a second flowchart of a flexible circuit board soldering method provided in an embodiment of the present application.

As shown in fig. 21, the method provided in the embodiment of the present application may further include the following steps:

s107: a first adhesive tape 71 is filled between the substrate layer 11 and the first flexible circuit board 21, the first adhesive tape 71 is annularly coated around the heat insulating material 8, and the first adhesive tape 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 insulating 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 is soldered to the bottom edge of the display panel 1 and the second flexible circuit board 22 is soldered to the first flexible circuit board 21, so that the first flexible circuit board 21 and the second flexible circuit board 22 are both fixed, due to the arrangement of the thermal insulation material 8 in the soldering process, a gap may exist between the surface of the first flexible circuit board 21 on the side close to the display panel 1 and the surface of the display panel 1 on the side close to the first flexible circuit board 21, and therefore, the gap is filled with the first back adhesive 71 to ensure the stability of the first flexible circuit board 21.

Fig. 22 schematically illustrates a third flowchart of a flexible circuit board soldering method provided in an embodiment of the present application.

As shown in fig. 22, the method provided in the embodiment of the present application may further include the following steps:

s108: filling a second back adhesive 72 between the first flexible circuit board 21 and the second flexible circuit board 22, wherein the second back adhesive 72 is located at the edge of the second end 212 of the first flexible circuit board 21; the second adhesive 72 is used to fix 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 a split structure, and the second flexible circuit board 22 is welded on the surface of one side of the first flexible circuit board 21, which is back to the display screen 1, a gap is left between the surfaces of the second flexible circuit board 22 and one side of the first flexible circuit board 1, which is back to the display screen 1, so that the stability of the second flexible circuit board 22 is poor, and therefore, the second gum 72 is filled at the edge of the second end 212 of the first flexible circuit board 21, so that the first flexible circuit board 21 and the second flexible circuit board 22 can be fixed.

Fig. 23 schematically illustrates a flow chart of a fourth flexible circuit board soldering method provided in the embodiment of the present application.

As shown in fig. 23, the method provided in the embodiment of the present application may further include the following steps:

s109: the terminal 51 of the BTB connector 5 is prepared on the 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, and the terminal 51 only needs to be completed before step S105, so as to avoid that the terminal 51 is prepared again to affect the display screen 1 when the second flexible circuit board 22 is welded to the first flexible circuit board 21.

With continued reference to fig. 23, the flexible circuit board soldering method 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, so that the middle frame 4 is used for fixing the display screen 1, the first flexible circuit board 21 and the second flexible circuit board 22, wherein the terminal 51 is located at the opening of the middle frame 4.

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

In a specific implementation, the seat 52 can be prepared after the preparation of the terminal 51 is completed, so that the terminal 51 can be correspondingly fastened to the seat 52.

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

Fig. 24 schematically shows a fifth flowchart of a flexible circuit board soldering method provided by an embodiment of the present application.

As shown in fig. 24, the method provided in the embodiment of the present application may further include the following steps:

s113: a hollow solder post 223 is provided on 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 pad 2211 is prepared.

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

In specific implementation, the motherboard pad 31 may be prepared while preparing the first flexible circuit board 21 and the second flexible circuit board 22, or may be prepared while preparing the welding column 223, and the preparation time of the motherboard pad 3 is not limited, and it is only required to ensure that the motherboard pad 31 is prepared at the corresponding position of the welding column 223.

S115: after the second flexible circuit board 22 is soldered to the first flexible circuit board 21, the middle frame 4 is assembled, so that the middle frame 4 is used for fixing the display screen 1, the first flexible circuit board 21 and the second flexible circuit board 22, wherein the soldering stud 223 is located at the opening of the middle frame 4.

S116: the mainboard 3 is buckled on the middle frame 4, the mainboard bonding pad 31 is heated through laser to melt the mainboard bonding pad 31, and under the extrusion action of the second flexible circuit board 22, the soldering tin melted by the mainboard bonding pad 31 flows to one side of the second flexible circuit board 22 back to the mainboard 3 from the welding column 223; after the solder is solidified, the solder is connected to the solder post 223 to fix the second flexible circuit board 22 and the motherboard 3, so as to electrically connect the second flexible circuit board 22 and the motherboard 3.

It should be noted that, in the above embodiments, the first to fifth flexible circuit board soldering methods are all soldered on the display screen 1, and the flexible circuit board soldering methods shown 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 soldering density achieved is low.

Fig. 25 schematically illustrates a sixth flowchart of a flexible circuit board soldering method provided in an embodiment of the present application.

As shown in fig. 25, the method provided in the embodiment of the present application 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 prepared in a convex shape, the second flexible circuit board 22 is prepared in a strip shape, and a plurality of first flexible circuit boards 21 and second flexible circuit boards 22 are prepared on the same flexible circuit board substrate, so that 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-shaped protrusion away from the bottom of the display screen 1, and the second end 212 is disposed with at least one first pad 2121, i.e., the first pad 2121 is prepared in the protrusion area.

In a specific implementation, the distribution and shape of the first pads 2121 are the same as those in step S102, and only the arrangement position is different from that in step S102, the arrangement position in step S102 is arranged on the edge side of the second end 212 of the rectangular-like first flexible circuit board 21, whereas in this embodiment, the first pads 2121 are prepared in the convex portion region of the first flexible circuit board 21 in the shape of a Chinese character 'tu'.

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 implemented in the same manner as step S104. At this time, the display panel 1 is soldered to the first flexible circuit board 21 to form a combined body.

S204: the terminal 51 of the BTB connector 5 is prepared on the 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: the seat 52 is prepared on the main board 3.

S206: the main board 3 is fastened to the middle frame 4, so that the terminal 51 is 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 combined body.

S207: the first pad 2121 extends from the first opening 41 of the middle frame 4, and the second pad 2211 extends from the second opening 42 of the middle frame 4, so that the first pad 2121 and the second pad 2211 are connected with the second pad 2211 by welding on the surface of the middle frame 4 opposite to the first flexible circuit board 21. In a specific implementation, the welding manner is shown in fig. 26. Since the middle frame 4 can bear temperature and pressure, the flexible circuit board welding method shown in the embodiment does not need heat insulation and control of pressure, and can achieve higher welding density. It should be noted that the shape of the middle frame 4 in the embodiment of the present application is only an exemplary illustration, and in the design of the partial middle frame 4, the opening area of the first opening 41 is relatively large, and most of the area of the first flexible circuit board 21 can protrude from the middle frame 4, so that the first pad 2121 and the second pad 2211 can be connected on the middle frame 4 by soldering more conveniently.

Fig. 27 schematically illustrates a seventh flowchart of a flexible circuit board soldering method provided in an embodiment of the present application.

As shown in fig. 27, the method provided in the embodiment of the present application 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 first flexible circuit board 21 and the second flexible circuit board 22 in step S301 are prepared in the same manner as 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 first pad 2121 and the second pad 2211 in step S302 are prepared in the same manner as in step S202.

S303: the first flexible circuit board 21 and the second flexible circuit board 22 are soldered to the second pad 2211 via the first pad 2121.

In specific implementation, the first flexible circuit board 21 and the second flexible circuit board 22 are welded, and then a combination body formed by the first flexible circuit board 21 and the second flexible circuit board 22 is assembled with the display screen 1, wherein the assembly mode of the combination body 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 this 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 flexible circuit board soldering methods provided above, and further include a flexible circuit board soldering method formed by forming one or more combinations of technical features in the embodiments described above, and it is easily understood that a person skilled in the art may combine, split, recombine, etc. the embodiments of the present application on the basis of several embodiments provided herein to obtain other embodiments, and these embodiments do not depart from the scope of the present application.

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

When the display screen is damaged by screen-splash, fragmentation and the like and needs to be replaced, the following steps are usually adopted for disassembling the display screen assembly welded in the first to fourth flexible circuit board welding methods as shown in the embodiment of the application:

s401: the display screen 1 is placed with its side facing away from the first flexible circuit board 21 facing downwards.

S402: and (5) dismounting the electronic equipment shell, the battery and the like.

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

S404: the middle frame 4 is removed.

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

It should be noted that, in the process of disassembling the electronic device shown in the foregoing embodiment, the middle frame needs to be removed, and the display screen 1 and the first flexible circuit board 21 need to be replaced, and for a combined body formed by the display screen 1 and the first flexible circuit board 21 shown in this embodiment of the application, the combined body may be installed in multiple models with different lengths of the second flexible circuit board 22, so that the display screen 1 and the first flexible circuit board 21 are normalized, and the universality of the display screen assembly may be improved.

The second electronic device dismantling process provided by the embodiment of the application. When the display screen is damaged by screen-splash, fragmentation and the like and needs to be replaced, the display screen assembly welded in the sixth flexible circuit board welding method disclosed by the embodiment of the application is usually disassembled by adopting the following steps:

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

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

S503: the display panel 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 display screen 1 and the first flexible circuit board 21 can be replaced without disassembling the middle frame 4, and the disassembling process is simple.

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

The welding method of the flexible circuit board can solve the problems that the flexible circuit board used by the current mobile phone display screen assembly is generally of an integrated convex structure, the utilization rate of the substrate of the flexible circuit board is low due to the convex structure, the waste of the substrate plate is caused due to the large waste area, and the manufacturing cost of the flexible circuit board is high; meanwhile, the problem that the flexible circuit board with the integrated structure cannot be universal among display screen assemblies with different specifications due to different specifications of the display screen assemblies of electronic equipment with different models 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 above embodiments are only intended to be specific embodiments of the present application, and are not intended to limit the scope of the embodiments of the present application, and any modifications, equivalent substitutions, improvements, and the like 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 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 edge of the bottom 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 terminal is connected with the second bonding pad through the first bonding pad so as to be connected to the second terminal;

when the display screen assembly is installed on an electronic device, the fourth end is used for being connected with a main board of the electronic device.

2. The display screen assembly of claim 1,

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 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 so as to protect the display screen.

3. The display screen assembly of claim 2,

a first back adhesive is filled between the substrate layer and the first flexible circuit board, and the first back adhesive is annularly coated 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 used for filling the heat insulation material is formed between the substrate layer and the first flexible circuit board.

4. The display screen assembly of claim 2,

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

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

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

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

and the fourth end is provided with a board-to-board connector, and when the display screen assembly is installed on the electronic equipment, the board-to-board connector is used for being connected with a mainboard of the electronic equipment.

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

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

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

9. A flexible circuit board soldering method applied to the display panel assembly according to any one of claims 1 to 8, 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;

and connecting the first flexible circuit board and the second flexible circuit board through the first welding disc and the second welding disc in a welding mode.

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

and 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 welding the first end of the first flexible circuit board to the bottom edge of the display screen so as to electrically connect the first flexible circuit board with the bottom edge of the display screen.

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

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

when the first flexible circuit board and the second flexible circuit board are connected through the first bonding pad and the second bonding pad in a welding mode, heat insulation materials are filled in the grooves to protect the display screen;

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

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

filling a first back adhesive between the substrate layer and the first flexible circuit board, wherein the first back adhesive is annularly coated around the heat insulation material; the first back glue 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.

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

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

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

preparing the first flexible circuit board into a convex shape, wherein the at least one first welding disc is positioned on the convex protruding part;

and the first bonding pad extends out of a first opening of the middle frame, the second bonding pad extends out of a second opening of the middle frame, so that the first bonding pad and the second bonding pad are in a state that the middle frame faces away from the surface of the first flexible circuit board and the second bonding pad are in welded connection, wherein the middle frame is located on one side, facing away from the display screen, of the first flexible circuit board.

15. The flexible circuit board soldering method according to any one of claims 9 to 14,

and fastening the fourth end of the second flexible circuit board with a mainboard of the electronic equipment through a board-to-board connector.

16. The method of soldering a flexible circuit board according to any one of claims 9 to 14,

before the first flexible circuit board and the second flexible circuit board are connected by welding through the first bonding pad and the second bonding pad, the method further comprises the following steps:

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

17. The flexible circuit board soldering method according to any one of claims 15 or 16, further comprising:

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

18. The flexible circuit board soldering method according to claim 17, wherein the soldering of the first pad and the second pad comprises: laser welding and/or heat press welding.