A method for manufacturing a soft-hard combined board in which a hard board is surrounded by a soft board

Abstract

The application provides a manufacturing method of a soft-hard combination board in which a hard board is surrounded by a soft board, and comprises the following steps: manufacturing a first inner layer soft board and covering a film; pasting the film; fast pressing; fast pressing the first soft board with the pasted film; baking the board; baking the fast pressed board to obtain a soft board layer; manufacturing a prepreg; laser cutting a window at a first exposed area of the soft board and a rivet hole position of a second prepreg, and the laser cutting of the window needs to be designed with a connecting bridge connected with a hard board area; manufacturing a first inner layer hard board; manufacturing a second inner layer hard board; depth control of the first inner layer hard board; depth control of the second inner layer hard board; using existing technologies to manufacture the board after the whole pressing and before the depth control uncovering; depth control uncovering; and performing forming, testing, appearance inspection and packaging on the soft-hard combination board semi-finished product after the uncovering to complete the production of the soft-hard combination board.

Description

TECHNICAL FIELD

[0001] The present application relates to a manufacturing method of a soft and hard combined circuit board, in particular to a manufacturing method of a soft and hard combined board in which a hard board is surrounded by a soft board. BACKGROUND

[0002] With the increasing demand for more functions of electronic products, electronic products need to be highly integrated, and as an important and indispensable printed circuit board for electronic products, it is also proposed to develop in the direction of "light, thin, short and small". Soft and hard combined boards have emerged as the times require, and have been widely used in electronic products. Therefore, it can be used in some products with special requirements, which has certain flexible area and certain rigid area, which helps to save internal product space, reduce product size and improve product performance.

[0003] In the prior art, it is usually required that the soft board width of the connection area of the soft board and the hard board is less than the hard board width. In the case where the soft board width is insufficient, the first inner layer soft board number is increased to solve the problem, which to some extent leads to the continuous increase of the number of layers and thickness, which is not conducive to the development in the direction of "thin". With the increase of the number of layers, the process manufacturing difficulty and manufacturing cost are increased, which is not conducive to mass production.

[0004] Therefore, the prior art has defects and needs to be improved. SUMMARY

[0005] The present application provides a production method of a soft and hard combined board, which realizes the operation and production of the local hard board, and realizes the production and manufacturing of the high-precision circuit board with local high-density welding and packaging.

[0006] The technical scheme provided by the present application is as follows: a manufacturing method of a soft and hard combined board in which a hard board is surrounded by a soft board, comprising the following steps:

[0007] First step: inner layer soft board manufacturing; selecting and cutting the soft board substrate, making the inner layer soft board circuit pattern through the pattern transfer technology, and making the rivet hole for pressing;

[0008] Second step: cutting the cover film; cutting the cover film of the PNL layout, the cut part being the exposed area, the exposed area being the surrounded area of the hard board, the cover film area surrounding the surrounded area, and the exposed area being cut with a cover film F alignment pattern;

[0009] Third step: pasting the cover film; the first inner layer soft board is subjected to brown oxidation treatment, the soft board exposed area alignment F pattern and the cover film F alignment pattern are overlapped, and the iron high temperature is fixed;

[0010] Fourth step: fast pressing; the first soft board with the pasted cover film is subjected to fast pressing;

[0011] Fifth step: baking plate; baking the plate that has been pressed to get the first inner layer soft plate;

[0012] Sixth step: prepreg production; the prepreg includes the first prepreg and the second prepreg, the first prepreg and the second prepreg are cut to open windows at the positions corresponding to the exposed area of the soft plate and the rivet hole, and the cut windows need to be designed with connecting bridges connected to the hard plate area;

[0013] Seventh step: production of the first inner layer hard plate; the first inner layer hard plate is provided, the bottom circuit pattern of the first inner layer hard plate is produced by graphic transfer technology, and the rivet hole for pressing is punched by a punching machine;

[0014] Eighth step: production of the second inner layer hard plate; the second inner layer hard plate is provided, the top circuit pattern of the second inner layer hard plate is produced by graphic transfer technology, and the rivet hole for pressing is punched by a punching machine;

[0015] Ninth step: depth control milling of the first inner layer hard plate; the bottom circuit pattern of the first inner layer hard plate is upward, and the position corresponding to the exposed area of the soft plate is depth control milled;

[0016] Tenth step: depth control milling of the second inner layer hard plate; the top circuit pattern of the second inner layer hard plate is upward, and the position corresponding to the exposed area of the soft plate is depth control milled;

[0017] Eleventh step: overall pressing; the first inner layer hard plate and the second inner layer hard plate are subjected to brown oxidation treatment, and after the brown oxidation treatment, the first inner layer hard plate, the first prepreg, the inner layer soft plate, the second prepreg and the second inner layer hard plate are stacked from top to bottom and then subjected to pressing to obtain a soft and hard combination plate in which the hard plate is surrounded by the soft plate;

[0018] Twelfth step: post-process.

[0019] Thirteenth step: forming, which further includes depth control milling;

[0020] In the preferred technical solution, the inner layer soft plate production of the first step is a single-sided soft plate, a double-sided soft plate or a multi-layer soft plate.

[0021] In the preferred technical solution, an alignment F pattern is designed beside the exposed area of the soft plate, the cutting pattern of the cover film is 0.5-0.6 mm larger than the whole exposed area of the soft plate, and the cover film area surrounds the hard plate area in the middle.

[0022] Preferably, the prepreg is a weak flow prepreg with a flowability less than 10%, and the weak flow prepreg has a gel flowability of 3-6%; the first prepreg and the second prepreg are cut to form windows at positions corresponding to the first exposed area of the soft plate and the rivet hole, the windows are 0.2-0.6 mm smaller than the whole exposed area, and a connecting bridge is designed at a position connected to the hard plate area, the connecting bridge is designed at a diagonal, and the width of the connecting bridge is controlled to be 1-2 mm.

[0023] Preferably, in the ninth step and the tenth step, the depth of the depth control milling is 40%-60% of the thickness of the inner hard plate.

[0024] Preferably, the depth control milling is performed at positions corresponding to the depth control milling in the ninth step and the tenth step, and the depth of the depth control milling is 40%-60% of the thickness of the first inner hard plate and the second inner hard plate.

[0025] Preferably, the hard plate surrounded by the soft plate is contained in the first inner hard plate, or the second inner hard plate, or both the first inner hard plate and the second inner hard plate.

[0026] Preferably, the first inner hard plate and the second inner hard plate are single-sided plates, double-sided plates, or multi-layer plates.

[0027] Preferably, the hard plate surrounded by the soft plate is at least one.

[0028] Compared with the prior art, the hard plate surrounded by the soft plate produced by the manufacturing method of the present application effectively solves the problem that the width of the soft plate is greater than the width of the hard plate in the connection area of the soft plate and the hard plate, increases the width of the soft plate for wiring, effectively reduces the thickness and the number of layers of the plate, reduces the production difficulty, improves the production efficiency and the yield of the product, greatly reduces the precision requirement of the production equipment, and thus realizes the overall effect of improving the product quality, reducing the product price, and improving the competitiveness. It conforms to the development direction of "thinness", solves the corresponding production problems, can be mass-produced, and can be developed vigorously. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments or the prior art, the drawings required to be used in the description of the embodiments or the prior art will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0030] Figure 1 is a schematic diagram of the inner layer soft plate circuit;

[0031] Figure 2 is a schematic diagram of the first inner layer soft plate circuit after covering the film.

[0032] Figure 3 is a schematic diagram of a prepreg structure;

[0033] Figure 4 is a design plan view of a prepreg connecting bridge;

[0034] Figure 5 is a schematic diagram of a depth control robbing of a first inner hard plate and a second inner hard plate;

[0035] Figure 6 is a schematic diagram of a pressing structure;

[0036] Figure 7 is a schematic diagram of a hard plate being surrounded by a soft plate to form a soft and hard combination plate product;

[0037] Figure 8 is a schematic diagram of a hard plate being surrounded by a soft plate to form a soft and hard combination plate plan view. DETAILED DESCRIPTION

[0038] In order to facilitate the understanding of the present application, the present application will be described in more detail below in conjunction with the accompanying drawings and specific embodiments. The preferred embodiments of the present application are shown in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described in this specification. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0039] It should be noted that when an element is referred to as being "fixed" to another element, it can be directly on the other element or there can be an intervening element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or there can be an intervening element. The terms "fixed", "integrally formed", "left", "right" and similar expressions used in this specification are only for the purpose of illustration and in the drawings, similar elements are designated with the same reference numerals.

[0040] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0041] Example 1: A soft and hard combination plate with a hard plate being surrounded by a soft plate, comprising a first inner hard plate 110, an inner soft plate 20 and a second inner hard plate 120, the first inner hard plate 110 and the second inner hard plate 120 can be a single-sided plate, a double-sided plate or a multi-layer plate, the inner soft plate 20 can be a single-sided soft plate, a double-sided soft plate or a multi-layer soft plate; the inner soft plate 20 can be divided into a first inner soft plate 210, a second inner soft plate 220, a third inner soft plate, a fourth inner soft plate and a fifth inner soft plate.

[0042] The first inner layer hard plate 110, the inner layer soft plate 20 and the second inner layer hard plate 120 are connected by using a weak flow glue prepreg with a gel flow of less than 10%, and the gel flow of the weak flow glue prepreg is 3-6%; the first prepreg 310 and the second prepreg 320 are laser cut to open windows at the positions corresponding to the first exposed area 211 of the soft plate and the rivet hole, and the laser cut opening window is 0.2-0.6mm smaller than the first exposed area 211 as a whole, and the position connected with the hard plate area is designed to have a connecting bridge 330, the connecting bridge 330 is designed to be diagonal, and the width of the connecting bridge 330 is controlled to be 1-2mm; the first prepreg 310 and the second prepreg 320 are prepregs for pressing between the hard plate and the soft plate; the hard plate is connected in sequence by the soft plate to form a soft and hard combination plate, which is the first inner layer hard plate 110, the first prepreg 310, the inner layer soft plate 20, the second prepreg 320 and the second inner layer hard plate 120, and after pressing, the first inner layer hard plate 110, the first inner layer soft plate 210 and the second inner layer hard plate 120 are electrically connected through the conductive hole.

[0043] Reference Figure 1 A soft plate substrate is provided, the inner layer soft plate 20 has a specification of 0.05mm H / Hoz without copper, the first inner layer soft plate 210 is made by using existing technology, the first inner layer soft plate circuit pattern 212 and the first exposed area 211 are made by using existing pattern transfer technology, and the rivet hole for pressing is punched by using a targeting machine;

[0044] Reference Figure 2 The cutting film 400 is laser cut, the PI glue layer of the cutting film 400 has a specification of 1025, the cutting film 400 area surrounds the hard plate area in the middle, the laser cutting pattern is 0.6mm larger than the first exposed area 211 of the soft plate as a whole, and the F alignment pattern is cut out, the first inner layer soft plate 210 is subjected to post-browning treatment, the first exposed area 211 of the first inner layer soft plate 210 is aligned with the F alignment pattern of the cutting film 400, and is fixed by using a soldering iron at a high temperature, the temperature of the soldering iron is set to be 340℃, the high temperature fixing time is 2 seconds, the first inner layer soft plate 210 with the cutting film 400 is subjected to rapid pressing, the rapid pressing temperature is controlled to be 180℃, the pressing time is controlled to be 3 minutes, the pressing pressure is controlled to be 35kg / c㎡, the baked plate is subjected to baking, the baking temperature is controlled to be 130℃, and the baking time is controlled to be 70 minutes, so as to obtain the first inner layer soft plate 210;

[0045] Reference Figure 3 , Figure 4, provide prepreg with flow less than 5%, prepreg specification is 1080, RC63%, laser cutting window in the first exposed area 211 of the first inner soft plate 210 and rivet hole position, laser cutting window is 0.4mm smaller than the first exposed area 211 as a whole, and the position connected with the hard plate area is designed to have a connecting bridge 330, the connecting bridge 330 is designed diagonally, and the width of the connecting bridge 330 is controlled to be 1.5mm;

[0046] Reference Figure 5 , provide inner hard plate, inner hard plate specification is 0.5mm H / Hoz without copper, make inner hard plate and hard plate pattern 140 by existing pattern transfer technology, and use a targeting machine to punch rivet holes for pressing, and control the depth of the first exposed area 211 of the first inner soft plate 210 by depth control to form a depth control knurl 130, the depth control knurl depth is 0.25mm;

[0047] Reference Figure 6 , the first inner hard plate 110 is subjected to brown oxidation treatment, and after the brown oxidation treatment, the first inner hard plate 110, the first prepreg 310, the first inner soft plate 210, the second prepreg 320 and the second inner hard plate 120 are stacked in order from top to bottom, and then subjected to pressing, the pressing pressure is 35kg / c㎡, and the high pressure time is 90min;

[0048] Reference Figure 7 、 Figure 8 , the pressed plate is subjected to the steps of existing technology from the whole pressing to the depth control uncovering, the depth control knurling is performed at the position of the first exposed area 211 of the first inner soft plate 210, the depth control knurling depth is 0.25mm, and the soft and hard combination plate semi-finished product after uncovering is subjected to forming, testing and appearance inspection, packaging, and the production of the hard plate surrounded by the soft plate is completed.

[0049] Example 2: A hard plate surrounded by a soft plate soft and hard combination plate, its structure is basically the same as that of example 1, the difference is that the first inner hard plate 110 and the second inner hard plate 120 are close to the prepreg surface and are non-patterned light plates.

[0050] The processing technology of the hard plate surrounded by the soft plate soft and hard combination plate of example 2 is the same as that of example 1.

[0051] Example 3: A hard plate surrounded by a soft plate soft and hard combination plate, its structure is basically the same as that of example 1, the difference is that the inner hard plate thickness is 0.7mm H / Hoz without copper.

[0052] The processing technology of the hard plate surrounded by the soft plate soft and hard combination plate of example 3 is the same as that of example 1.

[0053] The hard plate produced by the manufacturing method of the application effectively solves the problem that the soft plate width is less than the hard plate width in the connection area of the soft plate and the hard plate, increases the soft plate width for wiring, can effectively reduce the plate thickness and the number of layers, reduces the production difficulty, improves the production efficiency and the yield of the product, and further realizes the overall effect of improving the product quality, reducing the product price, and improving the competitiveness, which conforms to the development direction of the current "thin" direction.

[0054] It should be noted that the above technical features continue to be combined with each other to form various embodiments not listed above, which are considered to be within the scope of the description of the application; and for those skilled in the art, the above description can be improved or changed, and all these improvements and changes shall belong to the protection scope of the appended claims of the application.

Claims

1. A method for manufacturing a rigid-flex PCB where a rigid board is surrounded by a flexible board, characterized in that, Includes the following steps: Step 1: Inner flexible circuit board fabrication; Select and cut the flexible circuit board substrate, create the inner flexible circuit board circuit pattern using pattern transfer technology, and create the rivet holes for lamination; Step 2: Cut the cover film; Cut the cover film of PNL layout. The cut-off part is the exposed area. The exposed area is the area where the rigid board is trapped. The cover film area surrounds the trapped area in the middle, and the exposed area is cut with the cover film F alignment pattern. Step 3: Apply the cover film; The first inner layer flexible circuit board is browned, the F-alignment pattern of the exposed area of ​​the flexible circuit board is aligned with the F-alignment pattern of the cover film, and then fixed with a soldering iron at high temperature; Step 4: Quick Press; Quickly press the first flexible board with the cover film applied onto it. Step 5: Baking plate; Bake the pre-pressed plates to obtain the first inner soft layer plate; Step 6: Prepreg fabrication; The prepreg includes a first prepreg and a second prepreg. Windows are cut into the first and second prepregs at the corresponding exposed areas of the flexible board and rivet hole positions. The cut windows need to be designed with connecting bridges that connect to the rigid board area. Step 7: Fabricate the first inner layer rigid board; provide the first inner layer rigid board, use graphic transfer technology to create the bottom circuit pattern of the first inner layer rigid board, and use a punching machine to punch out the rivet holes for pressing. Step 8: Fabrication of the second inner layer rigid board; Provide the second inner layer rigid board, use graphic transfer technology to create the top layer circuit pattern of the second inner layer rigid board, and use a punching machine to punch out the rivet holes for pressing. Step 9: Depth control routing of the first inner layer rigid board; with the bottom circuit pattern of the first inner layer rigid board facing upwards, perform depth control routing on the corresponding exposed area of ​​the flexible board. Step 10: Depth control router for the second inner layer rigid board; with the top layer circuit pattern of the second inner layer rigid board facing upwards, perform depth control router on the corresponding exposed area of ​​the flexible board. Step 11: Overall lamination; The first inner hard layer board and the second inner hard layer board are browned. After browning, the first inner hard layer board, the first semi-cured sheet, the inner soft layer board, the second semi-cured sheet and the second inner hard layer board are stacked from top to bottom and then laminated to obtain a rigid-soft bonded board in which the hard layer board is surrounded by the soft layer board. Step 12: Post-processing; Step 13: Shaping, which also includes controlled depth milling.

2. The method for manufacturing a rigid-flex PCB with a rigid board surrounded by a flexible board according to claim 1, characterized in that, The first step involves the fabrication of the inner flexible PCB, which can be a single-sided flexible PCB, a double-sided flexible PCB, or a multi-layer flexible PCB.

3. The method for manufacturing a rigid-flex PCB with a rigid board surrounded by a flexible board according to claim 1, characterized in that: The exposed area of ​​the flexible board is designed with an F-shaped alignment. The cover film is cut with a pattern 0.5-0.6 mm larger than the overall exposed area of ​​the flexible board. The cover film area surrounds the rigid board area in the middle.

4. The method for manufacturing a rigid-flex PCB with a rigid board surrounded by a flexible board according to claim 1, characterized in that: The prepreg is a low-flow adhesive prepreg with a flowability of less than 10%, and the flowability of the adhesive prepreg is 3-6%. Windows are cut into the first exposed area of ​​the flexible board and the rivet hole positions corresponding to the first prepreg and the second prepreg. The cut windows are 0.2-0.6mm smaller than the overall exposed area. A connecting bridge is designed at the position where it connects with the rigid board area. The connecting bridge is designed diagonally and the width of the connecting bridge is controlled within 1-2mm.

5. The method for manufacturing a rigid-flex PCB with a rigid board surrounded by a flexible board according to claim 1, characterized in that: In steps nine and ten, the depth of the controlled-depth milling is 40%-60% of the thickness of the inner hardboard.

6. The method for manufacturing a rigid-flex PCB with a rigid board surrounded by a flexible board according to claim 1, characterized in that: The controlled-depth milling corresponds to the controlled-depth milling position in steps nine and ten, and the controlled-depth milling depth is 40%-60% of the thickness of the first inner hard plate and the second inner hard plate.

7. The method for manufacturing a rigid-flex PCB with a rigid board surrounded by a flexible board according to any one of claims 1-6, characterized in that: The rigid plate surrounded by the soft plate is contained within the first inner rigid plate, or the second inner rigid plate, or both the first inner rigid plate and the second inner rigid plate.

8. The method for manufacturing a rigid-flex PCB with a rigid board surrounded by a flexible board according to claim 7, characterized in that: The first inner hard layer board and the second inner hard layer board are single-sided, double-sided, or multi-layer boards.

9. The method for manufacturing a rigid-flex PCB with a rigid board surrounded by a flexible board according to claim 7, characterized in that: There is at least one hard board that is trapped by the soft board.

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