Circuit board assembly and preparation method thereof

Abstract

The invention provides a circuit board assembly and a preparation method thereof, the circuit board assembly comprises a flexible circuit board, a component, a reinforcing film and a supporting structure, the flexible circuit board is provided with a device area, and the component is arranged in the device area; the reinforcing film is arranged on one side, deviating from the component, of the flexible circuit board and is arranged corresponding to the component area; at least part of the supporting structure is arranged on the side, away from the flexible circuit board, of the reinforcing film. The edge of at least one side of the reinforcing film extends to the edge of the other side opposite to the edge of the reinforcing film. According to the circuit board assembly provided by the invention, when the component is electrically connected to the flexible circuit board through processes such as high-temperature reflow soldering in an SMT link, the stress from the edge of the reinforcing film to the central area of the reinforcing film can be relieved, and the problem of warping of the component area of the flexible circuit board is further avoided.

Description

Technical Field

[0001] The present application relates to the field of circuit boards, and in particular to a circuit board assembly and a preparation method thereof. Background Art

[0002] Flexible Printed Circuit (FPC) is a highly reliable and extremely flexible printed circuit board made of polyimide or polyester film as a substrate. It has the characteristics of high wiring density, light weight, thin thickness and good bendability.

[0003] The existing preparation process needs to be improved. Summary of the invention

[0004] The present application provides a circuit board assembly and a preparation method thereof, which can be used in a preparation process.

[0005] In order to solve the above technical problems, the first technical solution provided by the present application is: to provide a circuit board assembly, including:

[0006] A flexible circuit board having a device area;

[0007] Components are arranged in the device area;

[0008] A reinforcing film is arranged on a side of the flexible circuit board away from the component and is arranged corresponding to the component area;

[0009] The support structure is at least partially arranged on a side of the reinforcing film away from the flexible circuit board; and extends from at least one side edge of the reinforcing film to the other side edge opposite thereto; the support structure is used to relieve stress from the edge of the reinforcing film to the central area of ​​the reinforcing film.

[0010] In one embodiment, the support structure includes a plurality of strips, and the plurality of strips are all disposed on a side of the reinforcing film away from the flexible circuit board.

[0011] In one embodiment, the plurality of strips are arranged in parallel and at intervals; and the crossing areas of the cross-arranged strips are reused.

[0012] In one embodiment, at least some of the plurality of strips are arranged crosswise.

[0013] In one embodiment, the supporting structure includes a bonding portion, which is disposed on a side of the reinforcing film away from the flexible circuit board, and the bonding portion is in the form of a continuous seamless sheet or a sheet with a plurality of hollow portions.

[0014] In one embodiment, the laminating portion and the reinforcing film have the same shape and size, and a projection of the laminating portion on the flexible circuit board completely overlaps with a projection of the reinforcing film on the flexible circuit board.

[0015] In one embodiment, an adhesive layer is provided between the flexible circuit board and the reinforcing film, and the adhesive layer has a first thickness;

[0016] The support structure further includes a hooking portion connected to the edge of the bonding portion, wherein the hooking portion extends from the edge of the bonding portion to between the reinforcing film and the flexible circuit board and is disposed in the same layer as the adhesive layer;

[0017] Wherein, the portion of the hooking portion extending between the reinforcing film and the flexible circuit board has a second thickness, and the second thickness is less than or equal to the first thickness.

[0018] In one embodiment, the reinforcing film is rectangular, and the two hooking portions extend from the two short sides of the reinforcing film to between the reinforcing film and the flexible circuit board.

[0019] In one embodiment, the support structure and the reinforcement membrane are detachable.

[0020] In one embodiment, the material of the strip includes at least one of silicone, polyurethane, polyimide, polyester, thermoplastic elastomer, metal, heat-resistant glass and ceramic.

[0021] In order to solve the above technical problems, the second technical solution provided by the present application is: to provide a method for preparing a circuit board assembly, comprising:

[0022] Provide flexible circuit boards;

[0023] A reinforcing film is provided on one side of the flexible circuit board; wherein the reinforcing film is provided corresponding to the device area of ​​the flexible circuit board;

[0024] A support structure is provided on a side of the reinforcing film away from the flexible circuit board; wherein the support structure extends from at least one side edge of the reinforcing film to another side edge opposite thereto;

[0025] Mounting components in the device area of ​​the flexible circuit board; wherein the components are located on a side of the flexible circuit board away from the reinforcing film, thereby forming a circuit board assembly preform;

[0026] The circuit board assembly preform is placed in a high-temperature reaction furnace and treated at a first preset temperature for a first preset time to weld the components and the flexible circuit board together.

[0027] In one embodiment, the first preset temperature ranges from 150 to 260 degrees Celsius;

[0028] The first preset time ranges from 3 to 8 minutes.

[0029] In one embodiment, the step of welding the components and the flexible circuit board together further includes:

[0030] The support structure is disassembled.

[0031] The beneficial effects of the present application are different from those of the prior art. The circuit board assembly provided by the present application includes a flexible circuit board, a reinforcing film and a supporting structure, wherein the flexible circuit board has a device area, and the device area is provided with components; the reinforcing film is provided on one side of the flexible circuit board and is provided corresponding to the device area, and is used to reinforce the structure of the flexible circuit board; at least part of the supporting structure is provided on the side of the reinforcing film away from the flexible circuit board; and extends from at least one side edge of the reinforcing film to the other side edge opposite thereto. Specifically, the circuit board assembly provided by the present application is provided with a supporting structure, and the supporting structure extends from at least one side edge of the reinforcing film to the other side edge opposite thereto, so that when the components are electrically connected to the flexible circuit board through high-temperature reflow soldering and other processes in the SMT link, the supporting structure can improve the expansion and contraction of the reinforcing film caused by high temperature, relieve the stress from the edge of the reinforcing film to the center area of ​​the reinforcing film, and thus avoid the problem of warping of the device area of ​​the flexible circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0033] Figure 1 A schematic diagram of a partial structure of an embodiment of a circuit board assembly provided by the present application at a certain viewing angle;

[0034] Figure 2 A schematic diagram of a partial structure of an implementation of the first embodiment of the circuit board assembly provided by the present application at a viewing angle;

[0035] Figure 3 A schematic diagram of a partial structure of an implementation of the first embodiment of the circuit board assembly provided by the present application at a viewing angle;

[0036] Figure 4 A schematic diagram of a partial structure of an implementation of the first embodiment of the circuit board assembly provided by the present application at a viewing angle;

[0037] Figure 5 A schematic diagram of a partial structure of an implementation of the first embodiment of the circuit board assembly provided by the present application at a viewing angle;

[0038] Figure 6 A schematic diagram of a partial structure of an implementation of the first embodiment of the circuit board assembly provided by the present application at a viewing angle;

[0039] Figure 7 A schematic diagram of a partial structure of an implementation of the first embodiment of the circuit board assembly provided by the present application at a viewing angle;

[0040] Figure 8 A schematic diagram of a partial structure of an implementation of the first embodiment of the circuit board assembly provided by the present application at a viewing angle;

[0041] Fig. 9 A schematic diagram of a partial structure of an implementation of the first embodiment of the circuit board assembly provided by the present application at a viewing angle;

[0042] Fig.10 A schematic diagram of a partial structure of an implementation of the second embodiment of the circuit board assembly provided by the present application at a viewing angle;

[0043] Fig.11 A schematic diagram of the structure of the second embodiment of the circuit board assembly provided by the present application after removing the flexible circuit board and components;

[0044] Fig.12 A schematic structural diagram of an embodiment of a bonding portion provided in the present application;

[0045] Fig.13 A schematic structural diagram of another embodiment of the laminating portion provided in the present application;

[0046] Fig.14 A schematic flow chart of a first embodiment of a method for preparing a circuit board assembly provided in the present application;

[0047] Fig.15 A schematic flow chart of a second embodiment of a method for preparing a circuit board assembly provided in the present application. Specific implementation methods

[0049] The terms "first", "second", "third" in this application are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first", "second", "third" can expressly or implicitly include at least one of the features. In the description of this application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. In the embodiments of this application, all directional indications (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication also changes accordingly. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the steps or units listed, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or devices.

[0050] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0051] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0052] See also Figure 1 , Figure 1 A schematic diagram of the partial structure of an embodiment of a circuit board assembly provided in the present application at a certain viewing angle.

[0053] The present application provides a circuit board assembly, including a flexible circuit board 10 , a component 101 , a reinforcement film 20 and a support structure 30 .

[0054] Among them, the flexible circuit board 10 has a device area S, and components 101 with specific functions are arranged in the device area S. The flexible circuit board 10 also has a conductive pattern (not shown) for electrically connecting components 101 arranged on the same layer or different layers, and for electrically connecting with external devices, etc.

[0055] In some embodiments, the components 101 include but are not limited to at least one or more of capacitors, inductors, resistors, diodes, transistors, power supplies, antennas, and IC chips. As long as the circuit composed of the above components 101 has specific functions, it is acceptable and is not limited here.

[0056] In some embodiments, the flexible circuit board 10 can be a single-layer structure or a multi-layer stacked structure, wherein the flexible circuit board 10 with a single-layer structure is easy to prepare; the flexible circuit board 10 with a multi-layer stacked structure can be provided with a more complex circuit structure and richer circuit functions. The specific design is based on actual needs.

[0057] The reinforcement film 20 is disposed on a side of the flexible circuit board 10 away from the component 101 and is disposed corresponding to the device area S, and is used to reinforce the structure of the flexible circuit board 10 .

[0058] Specifically, the reinforcing film 20 is used to enhance the mechanical stability of the circuit board assembly. For example, the reinforcing film 20 can increase the mechanical stability of the flexible circuit board 10 in specific areas (such as the device area S and the bending area); the reinforcing film 20 is also used to help maintain the shape of the flexible circuit board 10 in places where a fixed shape or support is required to ensure reliable electrical connection; the reinforcing film 20 is also used as a support member in areas where the flexible circuit board 10 needs to be precisely aligned or welded, so as to facilitate precise positioning during automated assembly, etc.

[0059] In some embodiments, the material of the reinforcing film 20 includes a composite material or a specially designed plastic sheet. Specifically, the material selection of the reinforcing film 20 mainly considers its hardness, temperature resistance, cost and compatibility with other film layers in the circuit board assembly. During the design, the size, position and shape of the reinforcing film 20 will be carefully planned according to the needs of the actual application to ensure that the reinforcing effect is achieved without affecting the overall flexibility of the circuit board assembly.

[0060] In the embodiment of the present application, the material of the reinforcing film 20 is a flexible material, for example, the reinforcing film 20 is a polyimide film (PI film).

[0061] At least a portion of the support structure 30 is disposed on a side of the reinforcing film 20 away from the flexible circuit board 10 , and extends from at least one side edge of the reinforcing film 20 to another side edge opposite thereto.

[0062] It can be understood that when the components 101 are electrically connected to the flexible circuit board 10 through high-temperature reflow soldering and other processes in the SMT (Surface Mount Technology) link, the high temperature will cause the reinforcing film 20 to expand and shrink (generally shrink from the edge of the reinforcing film 20 toward the center, or expand from the center of the reinforcing film 20 toward the edge), and the expanded and shrunk reinforcing film 20 will further cause the device area S of the flexible circuit board 10 corresponding to it to be warped. The circuit board assembly provided in the present application is provided with a support structure 30, and the support structure 30 has a certain stress parameter, and the support structure 30 extends from at least one side edge of the reinforcing film 20 to the other side edge opposite thereto. In this way, when the components 101 are electrically connected to the flexible circuit board 10 through high-temperature reflow soldering and other processes in the SMT link, the support structure 30 can prevent the high temperature from causing the reinforcing film 20 to expand and shrink, thereby alleviating the stress in the area from the edge of the reinforcing film 20 to the center of the reinforcing film 20, thereby avoiding the problem of causing the device area S of the flexible circuit board 10 to be warped.

[0063] In some embodiments, the material of the support structure 30 includes a rigid material or a flexible material. The rigid material includes but is not limited to at least one of heat-resistant glass, ceramics and metal; the flexible material includes but is not limited to at least one of silicone, polyurethane, polyimide, polyester and thermoplastic elastomer.

[0064] It should be noted that the material of the support structure 30 is different from that of the reinforcing film 20. In some embodiments, the stress parameter of the support structure 30 is greater than the stress parameter of the reinforcing film 20, so as to better improve the expansion and contraction of the reinforcing film 20 caused by high temperature, thereby alleviating the stress from the edge of the reinforcing film 20 to the center of the reinforcing film 20, thereby avoiding the device area S of the flexible circuit board 10 from being warped due to the expansion and contraction of the reinforcing film 20.

[0065] See also Figure 2-Figure 11 , Figure 2 A schematic diagram of a partial structure of an implementation of the first embodiment of the circuit board assembly provided by the present application at a viewing angle; Figure 3 A schematic diagram of a partial structure of an implementation of the first embodiment of the circuit board assembly provided by the present application at a viewing angle; Figure 4 A schematic diagram of a partial structure of an implementation of the first embodiment of the circuit board assembly provided by the present application at a viewing angle; Figure 5 A schematic diagram of a partial structure of an implementation of the first embodiment of the circuit board assembly provided by the present application at a viewing angle; Figure 6 A schematic diagram of a partial structure of an implementation of the first embodiment of the circuit board assembly provided by the present application at a viewing angle; Figure 7 A schematic diagram of a partial structure of an implementation of the first embodiment of the circuit board assembly provided by the present application at a viewing angle; Figure 8 A schematic diagram of a partial structure of an implementation of the first embodiment of the circuit board assembly provided by the present application at a viewing angle; Fig. 9 A schematic diagram of a partial structure of an implementation of the first embodiment of the circuit board assembly provided by the present application at a viewing angle; Fig.10 A schematic diagram of a partial structure of an implementation of the second embodiment of the circuit board assembly provided by the present application at a viewing angle; Fig.11 A schematic diagram of the structure of the second embodiment of the circuit board assembly provided by the present application after removing the flexible circuit board and components; Fig.12 A schematic structural diagram of an embodiment of a bonding portion provided in the present application; Fig.13 This is a schematic structural diagram of another embodiment of the bonding portion provided in the present application.

[0066] See also Figure 2-Figure 9 In the first embodiment of the present application, the support structure 30 includes a plurality of strips 31 , and the plurality of strips 31 are all disposed on a side of the reinforcing film 20 away from the flexible circuit board 10 .

[0067] See also Figure 10-13 In the second embodiment of the present application, the supporting structure 30 includes a bonding portion 32, which is disposed on the side of the reinforcing film 20 away from the flexible circuit board 10, and the bonding portion 32 is in the form of a continuous seamless sheet or a sheet with multiple hollow portions B.

[0068] Specifically, by providing a plurality of strips 31 or bonding portions 32 on the side of the reinforcing film 20 away from the flexible circuit board 10, the plurality of strips 31 or bonding portions 32 can relieve the stress from the edge of the reinforcing film 20 to the center area of ​​the reinforcing film 20, thereby preventing the reinforcing film 20 from expanding or contracting due to high temperature, thereby avoiding the problem of warping of the device area S of the flexible circuit board 10.

[0069] Compared with the second embodiment, the support structure 30 provided in the first embodiment of the present application can save the cost of the support structure 30 .

[0070] Compared with the first embodiment, the support structure 30 provided in the second embodiment of the present application has a larger contact area between the fitting portion 32 and the reinforcing film 20, so the effect of improving the expansion and contraction of the reinforcing film 20 caused by high temperature is better.

[0071] in addition, Fig.13 The fitting portion 32 shown is compared to Fig.13 The fitting portion 32 shown can save the cost of the supporting structure 30 .

[0072] See also Figure 2-Figure 4 In some embodiments, the plurality of strips 31 are arranged in parallel and at intervals.

[0073] For example, refer to Figure 2 , a plurality of strip-shaped bodies 31 are arranged in parallel and at intervals along the first direction X. Specifically, by arranging a plurality of strip-shaped bodies 31 in parallel and at intervals along the first direction X, the plurality of strip-shaped bodies 31 can improve the expansion and contraction of the reinforcing film 20 caused by high temperature in the first direction X, thereby alleviating the stress from the edge of the reinforcing film 20 to the central region of the reinforcing film 20, and further avoiding the problem of warping of the device area S of the flexible printed circuit board 10 in the first direction X.

[0074] For example, refer to Figure 3 , a plurality of strip-shaped bodies 31 are arranged in parallel and at intervals along the second direction Y. Specifically, by arranging a plurality of strip-shaped bodies 31 in parallel and at intervals along the second direction Y, the plurality of strip-shaped bodies 31 can improve the expansion and contraction of the reinforcing film 20 caused by high temperature in the second direction Y, thereby alleviating the stress from the edge of the reinforcing film 20 to the central region of the reinforcing film 20, and further avoiding the problem of warping of the device area S of the flexible printed circuit board 10 in the second direction Y.

[0075] For example, refer to Figure 4 , a plurality of strip-shaped bodies 31 are arranged in parallel and at intervals along the third direction. Specifically, by arranging a plurality of strip-shaped bodies 31 in parallel and at intervals along the third direction, the plurality of strip-shaped bodies 31 can improve the expansion and contraction of the reinforcing film 20 caused by high temperature in the third direction, thereby alleviating the stress from the edge of the reinforcing film 20 to the central region of the reinforcing film 20, and further avoiding the problem of warping of the device area S of the flexible printed circuit board 10 in the third direction.

[0076] Wherein, the first direction X is perpendicular to the second direction Y; the third direction intersects both the first direction X and the second direction Y, and the included angles between the third direction and the first direction X and the second direction Y are not 90 degrees.

[0077] Refer to Figure 5-Figure 9 , in some embodiments, at least some of the plurality of strip-shaped bodies 31 are arranged in a cross manner, and the cross regions of the strip-shaped bodies 31 arranged in a cross manner are reused.

[0078] For example, refer to Figure 5 , the plurality of strip-shaped bodies 31 are arranged in a "square" shape. Specifically, by arranging the plurality of strip-shaped bodies 31 in a "square" shape, the plurality of strip-shaped bodies 31 arranged in a "square" shape respectively support the four edges of the reinforcing film 20, which is beneficial to improving the expansion and contraction of the edges of the reinforcing film 20 caused by high temperature, thereby alleviating the stress from the edge of the reinforcing film 20 to the central region of the reinforcing film 20, and further avoiding the problem of warping of the device area S of the flexible printed circuit board 10 in the third direction.

[0079] For example, refer to Figure 6 and Figure 7, a plurality of strip-shaped bodies 31 are arranged in a "日" character shape. Specifically, compared with the "口" character arrangement, the plurality of strip-shaped bodies 31 arranged in a "日" character shape add a strip-shaped body 31 extending along the first direction X or the second direction inside the "口" character, so as to further improve the improvement effect on the expansion and contraction of the reinforcing film 20 caused by high temperature in the first direction X or the second direction.

[0080] For example, refer to Figure 8 , a plurality of strip-shaped bodies 31 are arranged in a "田" character shape. Specifically, compared with the "口" character arrangement, the plurality of strip-shaped bodies 31 arranged in a "田" character shape add a strip-shaped body 31 extending along the first direction X and a strip-shaped body 31 extending along the second direction Y inside the "口" character, so as to improve the improvement effect on the expansion and contraction of the reinforcing film 20 caused by high temperature in both the first direction X and the second direction Y at the same time.

[0081] For example, refer to Fig. 9 , a plurality of strip-shaped bodies 31 are arranged in a "米" character shape. The plurality of strip-shaped bodies 31 arranged in a "米" character shape respectively support different positions of the four edges of the reinforcing film 20, so as to be conducive to improving the expansion and contraction of the edges of the reinforcing film 20 caused by high temperature, thereby relieving the stress from the edges of the reinforcing film 20 to the central region of the reinforcing film 20, and further avoiding the problem of warping of the device area S of the flexible printed circuit board 10 in the third direction.

[0082] In some embodiments, the material of the plurality of strip-shaped bodies 31 is also a flexible material. In this way, after the SMT process, the plurality of strip-shaped bodies 31 do not need to be peeled off from the reinforcing film 20, and can also play a dual reinforcing effect on the flexible printed circuit board 10.

[0083] In other embodiments, if the reinforcing film 20 and the support structure 30 are arranged corresponding to the non-bending part of the flexible printed circuit board 10, the material of the plurality of strip-shaped bodies 31 can also be a rigid material.

[0084] Refer to Fig.10 and Fig.11 , in the second embodiment of the present application, the shape and size of the fitting part 32 are the same as those of the reinforcing film 20, and the projection of the fitting part 32 on the flexible printed circuit board 10 completely overlaps with the projection of the reinforcing film 20 on the flexible printed circuit board 10.

[0085] Specifically, by setting that the projection of the fitting part 32 and the reinforcing film 20 completely overlap, the fitting part 32 can improve the expansion and contraction of any area of the reinforcing film 20 at high temperature, improve the blocking ability of the reinforcing film 20 against heat deformation, and further avoid the problem of warping of the device area S of the flexible printed circuit board 10.

[0086] Refer to Fig.10 or Fig.11In some embodiments, an adhesive layer 40 for bonding the flexible circuit board 10 and the reinforcing film 20 is provided between the flexible circuit board 10 and the reinforcing film 20, wherein the adhesive layer 40 has a first thickness. The support structure 30 further includes a hooking portion 33 connected to the edge of the bonding portion 32, the hooking portion 33 extends from the edge of the bonding portion 32 to between the reinforcing film 20 and the flexible circuit board 10 and is provided in the same layer as the adhesive layer 40. The portion of the hooking portion 33 extending between the reinforcing film 20 and the flexible circuit board 10 has a second thickness, which is less than or equal to the first thickness.

[0087] Specifically, a hooking portion 33 is provided to extend between the reinforcing film 20 and the flexible circuit board 10, and the supporting structure 30 is located at the bonding portion 32 on the side of the reinforcing film 20 away from the flexible circuit board 10, and the hooking portion 33 of the supporting structure 30 is located on the side of the reinforcing film 20 close to the flexible circuit board 10. Both can improve the expansion and contraction of the reinforcing film 20 caused by high temperature, relieve the stress from the edge of the reinforcing film 20 to the center area of ​​the reinforcing film 20, and thus avoid the problem of warping of the device area S of the flexible circuit board 10.

[0088] In addition, setting the second thickness to be less than or equal to the first thickness can prevent the thickness of the portion of the hooking portion 33 extending between the reinforcing film 20 and the flexible circuit board 10 from being too large, causing the flexible circuit board 10 and the reinforcing film 20 to peel off, thereby affecting the stability of the device.

[0089] In some embodiments, the material of the bonding portion 32 and the hooking portion 33 is the same. When the flexible circuit board 10 is a flexible circuit board, the material of the bonding portion 32 and the hooking portion 33 is also a flexible material. Therefore, after the SMT process, the bonding portion 32 and the hooking portion 33 do not need to be peeled off from the reinforcing film 20, and can also achieve a double reinforcement effect on the flexible circuit board 10.

[0090] In other embodiments, if the reinforcing film 20 and the supporting structure 30 are disposed corresponding to the non-bending portion of the flexible circuit board 10 , the material of the bonding portion 32 and the hooking portion 33 may also be a rigid material.

[0091] See also Fig.11 In some embodiments, the reinforcing film 20 is rectangular, and the two hooking portions 33 extend from the two short sides of the reinforcing film 20 to between the reinforcing film 20 and the flexible circuit board 10. It can be understood that when the reinforcing film 20 is rectangular, the two relatively short sides of the reinforcing film 20 are more likely to expand and contract due to high temperature. Therefore, in the embodiment of the present application, the hooking portions 33 are arranged to extend from the short sides of the reinforcing film 20 to between the reinforcing film 20 and the flexible circuit board 10, which can improve the expansion and contraction of the short sides of the reinforcing film 20 due to high temperature, thereby relieving the stress from the edge of the reinforcing film 20 to the central area of ​​the reinforcing film 20, thereby avoiding the problem of warping of the device area S of the flexible circuit board 10.

[0092] Furthermore, when the material of the support structure 30 is a rigid material, the support structure 30 and the reinforcement film 20 are arranged to be detachable. For example, the support structure 30 can be pulled out along the direction from one long side of the reinforcement film 20 to the other long side. In this way, the support structure 30 can be prevented from affecting the bending of the flexible circuit board 10. In addition, the disassembled support structure 30 can be reused to save costs.

[0093] Specifically, the circuit board assembly provided by the present application is provided with a support structure 30, the support material has certain stress parameters, and the support structure 30 extends from at least one side edge of the reinforcing film 20 to the other side edge opposite thereto, so that when the component 101 is electrically connected to the flexible circuit board 10 through a process such as high-temperature reflow soldering during the SMT link, the support structure 30 can improve the expansion and contraction of the reinforcing film 20 caused by high temperature, thereby relieving the stress from the edge of the reinforcing film 20 to the center area of ​​the reinforcing film 20, thereby avoiding the problem of warping of the device area S of the flexible circuit board 10.

[0094] See also Fig.14 , Fig.14 This is a schematic flow chart of a first embodiment of a method for preparing a circuit board assembly provided by the present application. Specifically, the present application further provides a method for preparing a circuit board assembly, including:

[0095] Step S1: providing a flexible circuit board.

[0096] The flexible circuit board can be a single-layer structure or a multi-layer stacked structure. The single-layer structure is simple to prepare, while the multi-layer stacked structure can be set with a more complex circuit structure and richer circuit functions. The design is based on actual needs.

[0097] Among them, the flexible circuit board is defined with a device area, and the device area is used for mounting and soldering components.

[0098] Step S2: a reinforcing film is provided on one side of the flexible circuit board.

[0099] Among them, the reinforcing film is set in the device area corresponding to the flexible circuit board. Specifically, the reinforcing film is used to enhance the mechanical stability of the circuit board assembly. For example, the reinforcing film can increase the mechanical stability of the flexible circuit board in specific areas (such as the device area S, the bending area); the reinforcing film is also used to help maintain the shape of the flexible circuit board in places where a fixed shape or support is required to ensure reliable electrical connection; the reinforcing film is also used as a support in areas where the flexible circuit board needs to be accurately aligned or welded, facilitating precise positioning during automated assembly, etc.

[0100] In some embodiments, the material of the reinforcing film includes a composite material or a specially designed plastic sheet. Specifically, the selection of the reinforcing film material mainly considers its hardness, temperature resistance, cost and compatibility with other film layers in the circuit board assembly. During the design, the size, position and shape of the reinforcing film will be carefully planned according to the needs of the actual application to ensure that the reinforcing effect is achieved without affecting the overall flexibility of the circuit board assembly.

[0101] In the embodiment of the present application, the material of the reinforcement film is a flexible material, for example, the reinforcement film is a polyimide film (PI film).

[0102] Step S3: a support structure is provided on the side of the reinforcing film facing away from the flexible circuit board.

[0103] Wherein, at least a portion of the support structure is disposed on a side of the reinforcement film away from the flexible circuit board; and extends from at least one side edge of the reinforcement film to another side edge opposite thereto.

[0104] In some embodiments, the material of the support structure includes a rigid material or a flexible material, wherein the rigid material includes but is not limited to at least one of heat-resistant glass, ceramics and metal; the flexible material includes but is not limited to at least one of silicone, polyurethane, polyimide, polyester and thermoplastic elastomer.

[0105] It should be noted that the material of the support structure is different from that of the reinforcing film. In some embodiments, the stress parameter of the support structure is greater than the stress parameter of the reinforcing film, so that the subsequent SMT process can better improve the expansion and contraction of the reinforcing film due to high temperature, thereby relieving the stress from the edge of the reinforcing film to the center of the reinforcing film, thereby avoiding the warping of the device area of ​​the flexible circuit board caused by the expansion and contraction of the reinforcing film.

[0106] The supporting structure can be Figures 2 to 13 Any embodiment provides a support structure 30.

[0107] Step S4: mounting components in the device area of ​​the flexible circuit board; wherein the components are located on the side of the flexible circuit board away from the reinforcing film, thereby forming a circuit board assembly preform.

[0108] In some embodiments, the components include but are not limited to at least one or more of capacitors, inductors, resistors, diodes, transistors, power supplies, antennas, and IC chips. As long as the circuit composed of the above components has specific functions, it is acceptable and is not limited here.

[0109] Step S5: placing the circuit board assembly preform in a high-temperature reaction furnace and treating it at a first preset temperature for a first preset time to weld the components and the flexible circuit board together.

[0110] The first preset temperature may range from 150 to 260 degrees Celsius. For example, the first preset temperature may be 150 degrees Celsius, 180 degrees Celsius, 210 degrees Celsius, 240 degrees Celsius, or 260 degrees Celsius, etc., which are not limited here. The first preset temperature may be different or the same at different welding stages of the circuit board assembly preform in the high temperature reaction furnace.

[0111] The first preset time may range from 3 minutes to 8 minutes. For example, the first preset time may be 3 minutes, 5 minutes, 7 minutes, or 8 minutes, etc., which is not limited here.

[0112] It can be understood that when the components are electrically connected to the flexible circuit board through high-temperature reflow soldering and other processes in the SMT link, the high temperature will cause the reinforcing film to expand and shrink, and the expanded and shrunk reinforcing film will then cause the device area of ​​the flexible circuit board corresponding to it to warp. The circuit board assembly provided by the present application is provided with a supporting structure, and the supporting structure has certain stress parameters, and the supporting structure extends from at least one side edge of the reinforcing film to the other side edge opposite thereto. In this way, when the components are electrically connected to the flexible circuit board through high-temperature reflow soldering and other processes in the SMT link, the supporting structure can prevent the high temperature from causing the reinforcing film to expand and shrink, thereby alleviating the stress from the edge of the reinforcing film to the center area of ​​the reinforcing film, thereby avoiding the problem of causing the device area of ​​the flexible circuit board to warp.

[0113] See also Fig.15 , Fig.15 A schematic flow chart of a second embodiment of a method for preparing a circuit board assembly provided in the present application.

[0114] In one embodiment, after step S5, the method further includes:

[0115] Step S6: disassembling the supporting structure.

[0116] Specifically, in this embodiment, the material of the supporting structure is a rigid material.

[0117] Among them, Fig.11 As shown, the support structure can be pulled out along the direction from one long side of the reinforcing film to the other long side, thereby preventing the support structure from affecting the bending of the flexible circuit board; in addition, the disassembled support structure can be reused, saving costs.

[0118] The above is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A circuit board assembly, characterized in that: include: A flexible circuit board having a device area; Components are arranged in the device area; A reinforcing film is arranged on a side of the flexible circuit board away from the component and is arranged corresponding to the component area; The support structure is at least partially disposed on a side of the reinforcement film away from the flexible circuit board, and extends from at least one side edge of the reinforcement film to another side edge opposite thereto.

2. The circuit board assembly according to claim 1, characterized in that: The supporting structure includes a plurality of strips, and the plurality of strips are all arranged on a side of the reinforcing film away from the flexible circuit board.

3. The circuit board assembly according to claim 2, characterized in that: The plurality of strips are arranged in parallel and at intervals.

4. The circuit board assembly according to claim 2, characterized in that: Some of the strips among the plurality of strips are arranged in a cross-shaped manner; and the cross-shaped regions of the cross-shaped strips are reused.

5. The circuit board assembly according to claim 1, characterized in that: The supporting structure comprises a bonding portion, which is arranged on a side of the reinforcing film away from the flexible circuit board, and the bonding portion is in the shape of a continuous seamless sheet or a sheet with a plurality of hollow portions.

6. The circuit board assembly according to claim 5, characterized in that: The laminating portion and the reinforcing film have the same shape and size, and a projection of the laminating portion on the flexible circuit board completely overlaps with a projection of the reinforcing film on the flexible circuit board.

7. The circuit board assembly according to claim 6, characterized in that: An adhesive layer is provided between the flexible circuit board and the reinforcing film, and the adhesive layer has a first thickness; The support structure further includes a hooking portion connected to the edge of the bonding portion, wherein the hooking portion extends from the edge of the bonding portion to between the reinforcing film and the flexible circuit board and is disposed in the same layer as the adhesive layer; Wherein, the portion of the hooking portion extending between the reinforcing film and the flexible circuit board has a second thickness, and the second thickness is less than or equal to the first thickness.

8. The circuit board assembly according to claim 7, characterized in that: The reinforcing film is rectangular, and the two hooking portions extend from the two short sides of the reinforcing film to between the reinforcing film and the flexible circuit board.

9. The circuit board assembly according to claim 7 or 8, characterized in that: The supporting structure and the reinforcing membrane are detachable.

10. The circuit board assembly according to claim 1, characterized in that: The material of the support structure includes at least one of silicone, polyurethane, polyimide, polyester, thermoplastic elastomer, metal, heat-resistant glass or ceramic.

11. A method for preparing a circuit board assembly, characterized in that: include: Provide flexible circuit boards; A reinforcing film is provided on one side of the flexible circuit board; wherein the reinforcing film is provided corresponding to the device area of ​​the flexible circuit board; A support structure is provided on a side of the reinforcing film away from the flexible circuit board; wherein the support structure extends from at least one side edge of the reinforcing film to another side edge opposite thereto; Mounting components in the device area of ​​the flexible circuit board; wherein the components are located on a side of the flexible circuit board away from the reinforcing film, thereby forming a circuit board assembly preform; The circuit board assembly preform is placed in a high-temperature reaction furnace and treated at a first preset temperature for a first preset time to weld the components and the flexible circuit board together.

12. The preparation method according to claim 11, characterized in that: The first preset temperature ranges from 150 to 260 degrees Celsius; The first preset time ranges from 3 to 8 minutes.

13. The preparation method according to claim 11, characterized in that: The step of welding the components and the flexible circuit board together further comprises: The support structure is disassembled.

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