A method for preparing a rigid-flexible board with a main board and a secondary board of the same thickness

Abstract

The present invention relates to a preparation method of a rigid-flexible board having a main board and a sub-board with the same thickness, the method comprising the following steps: providing a first rigid-flexible board and a second rigid-flexible board, the first rigid-flexible board comprising a first main board and a first sub-board, milling off a first empty board of the first main board and attaching protective tape to the upper and lower surfaces of the first sub-board; the second rigid-flexible board comprising a second main board and a second sub-board, milling off a second empty board of the second main board and attaching protective tape to the upper and lower surfaces of the second sub-board; providing a first outer layer board and a second outer layer board, the first outer layer board comprising a first graphic area and a first blank area, the second outer layer board comprising a second graphic area and a second blank area; stacking and pressing the first outer layer board, a PP layer, a first rigid-flexible board, a PP layer, a second rigid-flexible board, a PP layer and a second outer layer board in order from top to bottom; milling off the first blank area and the second blank area, removing the protective tape, and obtaining a rigid-flexible board having the same thickness as the main board and the sub-board.

Description

Technical Field

[0001] The present invention relates to the field of rigid-flex boards, and in particular to a method for preparing a rigid-flex board with a main board and a secondary board having the same thickness. Background Art

[0002] A rigid-flex PCB (rigid-flexible PCB) is a circuit board that combines a rigid printed circuit board (PCB) and a flexible printed circuit board (FPC) through a specific process. The rigid portion offers excellent mechanical strength and stability and is typically used to mount fixed electronic components such as chips, resistors, and capacitors. The flexible portion, with its bendable and foldable properties, can adapt to various spatial layouts and dynamic application requirements.

[0003] In a rigid-flexible board, the rigid area of ​​the rigid-flexible board that contains all the layers of circuits is called the main board, which generally refers to the rigid part with a thicker board thickness; the rigid area of ​​the rigid-flexible board that only contains some layers of circuits is called the sub-board, which generally refers to the rigid part with a thinner board thickness.

[0004] As the design of rigid-flex PCBs becomes more and more complex, a process of laminating multiple sub-rigid-flex PCBs (hereinafter referred to as daughter boards) to form a complex mother rigid-flex PCB (hereinafter referred to as motherboard) has emerged. In this process, the main boards of the daughter boards are aligned up and down, and the sub-boards of the daughter boards are aligned up and down, and then pressed into a motherboard. However, since the main boards of the daughter boards are thicker than the sub-boards, after lamination and lamination, the main boards of the motherboards will be much thicker than the sub-boards, which is not conducive to the customer's subsequent patch installation and use. Summary of the Invention

[0005] In order to overcome the above problems, the present invention provides a method for preparing a rigid-flexible board with a main board and a secondary board of the same thickness. The technical solution adopted by the present invention to solve the technical problem is as follows:

[0006] A method for preparing a rigid-flexible board with a main board and a secondary board of the same thickness, comprising the following steps:

[0007] Step S1: providing a first rigid-flexible board, the first rigid-flexible board including a first main board and a first sub-board, the first main board including a first blank board, and the first blank board having no graphic design;

[0008] Step S2: Mill off the first empty plate and apply protective tape to the upper and lower surfaces of the first sub-plate;

[0009] Step S3: providing a second rigid-flexible board, the second rigid-flexible board including a second main board and a second sub-board, the second main board including a second blank board, and the second blank board having no graphic design;

[0010] Step S4: Mill off the second empty plate and apply protective tape on the upper and lower surfaces of the second sub-plate;

[0011] Step S5: providing a first outer layer plate and a second outer layer plate, wherein the first outer layer plate includes a first graphic area and a first blank area, and the second outer layer plate includes a second graphic area and a second blank area;

[0012] Step S6: Arrange the stack and press it together. The order of the stack from top to bottom is the first outer layer board, PP layer, first rigid-flex board, PP layer, second rigid-flex board, PP layer, and second outer layer board. The projection of the PP layer on the first main board / second main board overlaps with the first main board / second main board.

[0013] Step S7: milling off the first blank area and the second blank area, removing the protective tape, and obtaining a rigid-flex board with the same thickness as the main board and the sub-board.

[0014] Furthermore, the first rigid-flexible board and the second rigid-flexible board are both sub-rigid-flexible boards that have undergone lamination, drilling, electroplating, pattern transfer, surface treatment, solder mask and text processing.

[0015] Furthermore, the first main board and the first sub-board are connected via a flexible board, and the second main board and the second sub-board are connected via a flexible board.

[0016] Furthermore, in step S2, the first empty plate is milled out by controlled depth milling; and in step S4, the second empty plate is milled out by controlled depth milling.

[0017] Furthermore, in step S6, the first graphic area pair is located directly above the first main board, the first main board pair is located directly above the second main board, and the second main board pair is located directly above the second graphic area to form a rigid main board structure.

[0018] Furthermore, the first blank area is located above the first sub-panel to protect the first sub-panel; the first sub-panel pair is located directly above the second sub-panel to form a rigid sub-panel structure; and the second blank area is located below the second sub-panel to protect the second sub-panel.

[0019] Furthermore, between step S6 and step S7, drilling, electroplating, pattern transfer, surface treatment, solder mask, text and molding processes are also included to make through holes on the rigid mainboard structure and complete the production of graphic circuits in the first graphic area and the second graphic area.

[0020] Furthermore, in step S7, the first blank area and the second blank area are milled away by milling blind grooves.

[0021] The beneficial effects of the present invention are:

[0022] The method includes the following steps: providing a first rigid-flexible board and a second rigid-flexible board, the first rigid-flexible board including a first main board and a first sub-board, milling off the first empty board of the first main board and applying protective tape to the upper and lower surfaces of the first sub-board; the second rigid-flexible board including a second main board and a second sub-board, milling off the second empty board of the second main board and applying protective tape to the upper and lower surfaces of the second sub-board; providing a first outer layer board and a second outer layer board, the first outer layer board including a first graphic area and a first blank area, and the second outer layer board including a second graphic area and a second blank area; stacking and pressing the boards together in the order of first outer layer board, PP layer, first rigid-flexible board, PP layer, second rigid-flexible board, PP layer, and second outer layer board from top to bottom; milling off the first and second blank areas, and removing the protective tape. This method first mills off the empty layer structure of the main board of the daughter board, then presses them together to obtain a rigid-flexible board with the same thickness as the main board and the sub-board. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, wherein:

[0024] Figure 1 This is a cross-section of the stacked structure of the first rigid-flexible board and the second rigid-flexible board of the present invention. Figure 1 ;

[0025] Figure 2 This is a cross-section of the stacked structure of the first rigid-flexible board and the second rigid-flexible board of the present invention. Figure 2 ;

[0026] Figure 3 This is a cross-section of the stacked structure of the first rigid-flexible board and the second rigid-flexible board of the present invention. Figure 3 ;

[0027] Figure 4 This is an exploded cross-sectional view of the stacked structure of the rigid-flex board with the same thickness of the main board and the auxiliary board before being pressed together;

[0028] Figure 5 This is a cross-sectional view of a stacked structure of a rigid-flex board having a main board and a secondary board of the same thickness according to the present invention;

[0029] Figure 6 It is a cross-sectional view of the stacked structure of the rigid-flex board in the prior art.

[0030] Figure number mark:

[0031] 100, first rigid-flex board; 101, first main board; 1011, first blank board; 102, first auxiliary board;

[0032] 200, second rigid-flex board; 201, second main board; 2011, second blank board; 202, second auxiliary board;

[0033] 300, first outer layer; 301, first graphic area; 302, first blank area;

[0034] 400, second outer layer; 401, second graphic area; 402, second blank area;

[0035] 500, PP layer;

[0036] 600. Protective tape. DETAILED DESCRIPTION

[0037] In order to better understand the purpose, structure and function of the present invention, the following is a further detailed description of a specific embodiment of the present invention "a method for preparing a rigid-flexible composite board with a main board and a sub-board of the same thickness" in conjunction with the accompanying drawings.

[0038] In the prior art, two sub-rigid-flex boards (hereinafter referred to as daughter boards) are pressed together to form a complex mother rigid-flex board (hereinafter referred to as motherboard). The main boards of the daughter boards are aligned up and down, and the sub boards of the daughter boards are aligned up and down, and then pressed together to form a motherboard. However, since the main boards of the daughter boards are thicker than the sub boards, after superposition and pressing, the main boards of the motherboards will be much thicker than the sub boards, as shown in the attached figure. Figure 6 In the case of such a large thickness difference, it is not conducive to the customer's subsequent patch installation and use; therefore, based on this problem, the present invention provides a method for preparing a rigid-flexible board with a main board and a sub-board of the same thickness, which mainly includes the following steps:

[0039] Step S1: See Figure 1 , providing a first rigid-flexible board 100, the first rigid-flexible board 100 including a first main board 101 and a first sub-board 102, the first main board 101 including a first blank board 1011, and the first blank board 1011 has no graphic design;

[0040] Step S2: See Figure 2 and Figure 3 , mill off the first empty plate 1011, and stick protective tape 600 on the upper and lower surfaces of the first sub-plate 102 to protect and isolate the first sub-plate 102;

[0041] Step S3: See Figure 1 , providing a second rigid-flex board 200, the second rigid-flex board 200 including a second main board 201 and a second sub-board 202, the second main board 201 including a second empty board 2011, and the second empty board 2011 has no graphic design;

[0042] Step S4: See Figure 2 and Figure 3 , mill off the second empty plate 2011, and stick protective tape 600 on the upper and lower surfaces of the second sub-plate 202 to provide protection and isolation for the second sub-plate 202;

[0043] Step S5: providing a first outer layer plate 300 and a second outer layer plate 400, wherein the first outer layer plate 300 includes a first graphic area 301 and a first blank area 302, and the second outer layer plate 400 includes a second graphic area 401 and a second blank area 402. In this step, the first graphic area 301 and the first blank area 302, the second graphic area 401 and the second blank area 402 are all core plates without patterns;

[0044] Step S6: Lamination and lamination, see Figure 5 The stacking order from top to bottom is the first outer layer board 300, the PP layer 500, the first rigid-flex board 100, the PP layer 500, the second rigid-flex board 200, the PP layer 500, and the second outer layer board 400; the projection of the PP layer 500 on the first main board 101 / second main board 201 overlaps with the first main board 101 / second main board 201, so that in the subsequent lamination process, the PP layer 500 bonds the first graphic area 301, the first main board 101, the second main board 201, and the second graphic area 401 together and plays an electrical insulation role;

[0045] Step S7: mill off the first blank area 302 and the second blank area 402, remove the protective tape 600, and obtain the following: Figure 5 The main board and sub-board are of the same thickness.

[0046] See further Figure 1 In this embodiment, the first rigid-flexible board 100 and the second rigid-flexible board 200 are both sub-rigid-flexible boards that have undergone pressing, drilling, electroplating, pattern transfer, surface treatment, solder mask and text processing; the first main board 101 and the first sub-board 102 are connected by a flexible board, and the second main board 201 and the second sub-board 202 are connected by a flexible board.

[0047] See further Figure 2 In this embodiment, the first empty plate 1011 is milled out by controlled depth milling in step S2, and the second empty plate 2011 is milled out by controlled depth milling in step S4 to reduce the thickness of the main board.

[0048] See further Figure 5 In this embodiment, in step S6, the shape and size of the first main board 101 in the first graphic area 301 are consistent with the first main board 101, and it is located directly above the first main board 101; the shape and size of the first main board 101 are consistent with the second main board 201, and it is located directly above the second main board 201; the shape and size of the second main board 201 are consistent with the second graphic area 401, and it is located directly above the second graphic area 401. The above stacked structure forms a rigid main board structure.

[0049] More specifically, in this embodiment, in step S6, the first blank area 302 is located above the first sub-panel 102 to protect the first sub-panel 102 and prevent the first sub-panel 102 from being corroded and damaged in subsequent processes; the first sub-panel 102 is consistent in shape and size with the second sub-panel 202 and is located directly above the second sub-panel 202 to form a rigid sub-panel structure; the second blank area 402 is located below the second sub-panel 202 to protect the second sub-panel 202 and prevent the second sub-panel 202 from being corroded and damaged in subsequent processes.

[0050] It should be noted that, in this embodiment, between step S6 and step S7, drilling, electroplating, graphic transfer, surface treatment, solder mask, text and molding processes are also included. Through these processes, through holes can be made on the rigid mainboard structure, and the production of graphic circuits in the first graphic area 301 and the second graphic area 401 can be completed.

[0051] Furthermore, since protective tape 600 is affixed to the upper and lower surfaces of the first sub-panel 102 and protective tape 600 is also affixed to the upper and lower surfaces of the second sub-panel 202, in the subsequent pressing process, there is no PP layer 500 between the first blank area 302 and the first sub-panel 102 and between the second blank area 402 and the second sub-panel 202, so they will not be bonded together. In step S7, the connection between the first blank area 302 and the first graphic area 301 and the connection between the second blank area 402 and the second graphic area 401 are cut off by milling blind grooves, and the first blank area 302 and the second blank area 402 can be removed.

[0052] In summary, this method utilizes the structure of the main board of the rigid-flexible board having an empty board without graphic circuit design. The first empty board 1011 and the second empty board 2011 are first milled out by controlled depth milling, and then pressed together, so that a rigid-flexible board with the same thickness of the main board and the sub-board can be obtained. During the pressing process, the first blank area 302 of the first outer layer board 300 and the second blank area 402 of the second outer layer board 400 are retained to protect the first sub-board 102 and the second sub-board 202 of the daughter board, and prevent these sub-boards that have completed circuit production from being corroded or damaged during the subsequent drilling, electroplating, graphic transfer, surface treatment, solder mask, text and molding processes of the main board, thereby ensuring the quality of the finished sub-board. Using this method, a high-quality rigid-flexible board with the same thickness of the main board and sub-board can be obtained, which solves the problem that the thickness of the main board of a high-layer rigid-flexible board is much larger than the thickness of the sub-board.

[0053] It will be understood that the present invention is described by way of some embodiments, and it will be appreciated by those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are intended to be protected by the present invention.

[0054] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

Claims

1. A method for preparing a rigid-flexible board with a main board and a secondary board of the same thickness, characterized in that: The steps include: Step S1: providing a first rigid-flexible board (100), wherein the first rigid-flexible board (100) comprises a first main board (101) and a first sub-board (102), wherein the first main board (101) comprises a first blank board (1011), and the first blank board (1011) has no graphic design; Step S2: milling off the first empty plate (1011), and applying protective tape (600) to the upper and lower surfaces of the first auxiliary plate (102); Step S3: providing a second rigid-flexible board (200), wherein the second rigid-flexible board (200) comprises a second main board (201) and a second sub-board (202), wherein the second main board (201) comprises a second blank board (2011), and the second blank board (2011) has no graphic design; Step S4: milling off the second empty plate (2011), and applying protective tape (600) to the upper and lower surfaces of the second auxiliary plate (202); Step S5: providing a first outer layer plate (300) and a second outer layer plate (400), wherein the first outer layer plate (300) includes a first graphic area (301) and a first blank area (302), and the second outer layer plate (400) includes a second graphic area (401) and a second blank area (402); Step S6: arranging the stack and laminating the stack, wherein the stack is arranged in the order from top to bottom: the first outer layer board (300), the PP layer (500), the first rigid-flexible board (100), the PP layer (500), the second rigid-flexible board (200), the PP layer (500), and the second outer layer board (400); the projection of the PP layer (500) on the first main board (101) / the second main board (201) overlaps with the first main board (101) / the second main board (201); Step S7: milling off the first blank area (302) and the second blank area (402), removing the protective tape (600), and obtaining a rigid-flexible board with the same thickness for the main board and the auxiliary board.

2. The method for preparing a rigid-flex board with a main board and a secondary board of the same thickness according to claim 1, characterized in that: The first rigid-flexible board (100) and the second rigid-flexible board (200) are both sub-rigid-flexible boards that have undergone lamination, drilling, electroplating, pattern transfer, surface treatment, solder mask and text processing.

3. The method for preparing a rigid-flex board with a main board and a secondary board of the same thickness according to claim 2, characterized in that: The first main board (101) and the first sub-board (102) are connected via a flexible board, and the second main board (201) and the second sub-board (202) are connected via a flexible board.

4. The method for preparing a rigid-flex board with a main board and a secondary board of the same thickness according to claim 1, characterized in that: In the step S2, the first empty plate (1011) is milled out by controlled depth milling; and in the step S4, the second empty plate (2011) is milled out by controlled depth milling.

5. The method for preparing a rigid-flex board with a main board and a sub-board of the same thickness according to claim 1, characterized in that: In step S6, the first graphic area (301) is located directly above the first main board (101), the first main board (101) is located directly above the second main board (201), and the second main board (201) is located directly above the second graphic area (401) to form a rigid main board structure.

6. The method for preparing a rigid-flexible board with a main board and a sub-board of the same thickness according to claim 5, characterized in that: The first blank area (302) is located above the first sub-panel (102) to protect the first sub-panel (102); the first sub-panel (102) is located directly above the second sub-panel (202) to form a rigid sub-panel structure; and the second blank area (402) is located below the second sub-panel (202) to protect the second sub-panel (202).

7. The method for preparing a rigid-flexible board with a main board and a sub-board of the same thickness according to claim 6, characterized in that: Between step S6 and step S7, drilling, electroplating, pattern transfer, surface treatment, solder mask, text and molding processes are also included to make through holes on the rigid mainboard structure and complete the production of the pattern circuits of the first pattern area (301) and the second pattern area (401).

8. The method for preparing a rigid-flexible board with a main board and a sub-board of the same thickness according to claim 7, characterized in that: In the step S7, the first blank area (302) and the second blank area (402) are milled out by milling blind grooves.

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