阅读说明：本技术 一种非对称性刚挠结合板的制作方法 (Manufacturing method of asymmetric rigid-flex printed circuit board ) 是由 郑伟生 关志锋 李超谋 刘国汉 房鹏博 于 2021-09-30 设计创作，主要内容包括：本发明提供的非对称性刚挠结合板的制作方法包括S1,刚挠主板的盲孔制作；S2,于刚挠副板进行制孔；S3,制作盲槽板；S4,一次压合；S5,二次压合；S6,外层开盖,取出阻胶材料。由上述方案可见,将此种带有与挠性板重合盲槽的非对称性外层副板刚挠结合板进行拆解,拆解成刚挠的部分与盲槽的部分,将复杂结构拆解为两种常见工艺进行分别实现,分别进行制作盲槽段的孔,刚挠主板的孔及刚挠副板的孔,简化工艺,有效减少控制过程难点。(The manufacturing method of the asymmetric rigid-flex printed circuit board comprises the steps of S1, manufacturing blind holes of a rigid-flex main board; s2, drilling holes on the rigid-flex auxiliary plate; s3, manufacturing a blind groove plate; s4, primary pressing; s5, secondary pressing; and S6, opening the outer layer, and taking out the glue blocking material. According to the scheme, the asymmetric outer-layer auxiliary plate rigid-flexible combined plate with the blind groove coincident with the flexible plate is disassembled into the rigid-flexible part and the blind groove part, the complex structure is disassembled into two common processes to be respectively realized, the holes of the blind groove section, the holes of the rigid-flexible main plate and the holes of the rigid-flexible auxiliary plate are respectively manufactured, the process is simplified, and the control process difficulty is effectively reduced.)

1. A manufacturing method of an asymmetric rigid-flex printed circuit board is characterized by comprising the following steps:

s1, manufacturing blind holes of the rigid flexible main board, manufacturing patterns on the sub-board, pre-controlling depth, sticking a high-temperature polyimide adhesive tape for a resist adhesive, drilling the first layer to the fourth layer, and manufacturing rear holes according to resin plug holes;

s2, making holes in the rigid-flex auxiliary plate, making patterns on the fourth layer and the fifth layer, pasting a glue blocking and filling adhesive tape on the fifth layer, laminating the first to sixth layers of rigid-flex plates, and drilling the first to sixth layers of rigid-flex plates;

s3, manufacturing a blind groove plate, and laminating the seventh layer to the tenth layer;

s4, performing primary pressing, namely pressing the first to tenth layers, filling a glue blocking material in the blind groove, adding a PI filling adhesive tape into the inner layer cavity, and performing primary pressing on the first to tenth layers;

s5, secondary pressing, manufacturing an outer layer through hole, and performing secondary pressing on the first to tenth layers;

and S6, opening the outer layer, and taking out the glue blocking material.

2. The method for manufacturing an asymmetric rigid-flex printed circuit board according to claim 1, wherein:

and (5) taking the rigid-flex main board obtained after the step S1 as an inner core board.

3. The method for manufacturing an asymmetric rigid-flex printed circuit board according to claim 2, wherein:

in step S2, a blackening process is performed before the cover is opened.

4. The method for manufacturing an asymmetric rigid-flex printed circuit board according to claim 3, wherein:

in step S3, the blind groove is made of a glue blocking material to avoid glue overflow.

5. The method for manufacturing an asymmetric rigid-flex printed circuit board according to claim 4, wherein:

in the step S3, the blind slot plate and the rigid-flex plate are subjected to hole milling.

6. The method for manufacturing an asymmetric rigid-flex printed circuit board according to claim 5, wherein:

in step S3, patterns of the sixth layer and the seventh layer are produced, and a step is milled so that the rigid-flex board is not raised when pressed.

7. The method for manufacturing an asymmetric rigid-flex printed circuit board according to claim 6, wherein:

the blind groove plate and the rigid-flex plate are consistent in size.

8. The method for manufacturing an asymmetric rigid-flex printed circuit board according to claim 7, wherein:

and the glue blocking material in the blind groove adopts sectional materials to block glue.

9. The method for manufacturing an asymmetric rigid-flex printed circuit board according to claim 8, wherein:

the pressing of the blind groove plate and the pressing of the rigid flexible plate are carried out in the same press.

10. The method for manufacturing an asymmetric rigid-flex printed circuit board according to any one of claims 1 to 9, characterized in that:

if the holes of the first to the sixth layers are not plugged, the outer layer adhesive tape is needed to be used for sealing the holes on the 1 surface when the first to the ten layers are pressed.

Technical Field

The invention belongs to the technical field of circuit boards, and particularly relates to a manufacturing method of an asymmetric rigid-flex printed circuit board.

Background

In recent decades, the Printed Circuit Board (PCB) manufacturing industry in China has been developed rapidly, and the Printed Circuit Board has been developed from a single layer to a double-sided Board, a multi-layer Board and a flexible Board, and has been developed to high precision, high density and high reliability. The size is continuously reduced, the cost is reduced, and the performance is improved, so that the printed circuit board still keeps strong vitality in the development process of future electronic products. The development trend of the production and manufacturing technology of the future printed circuit board is to develop the printed circuit board in the directions of high density, high precision, fine aperture, fine lead, small spacing, high reliability, multilayering, high-speed transmission, light weight and thin type. In recent years, flexible printed circuit boards have been developed rapidly and have begun to be developed toward rigid-flex printed boards, which are one of the major growth points of the PCB industry in the future.

With the development of rigid-flex boards, the design of asymmetric rigid-flex boards is more and more common. The asymmetric rigid-flex printed circuit board is also called a main rigid-flex printed circuit board and an auxiliary rigid-flex printed circuit board, and means that one rigid-flex printed circuit board has two thicknesses, namely a main board and an auxiliary board, which are mainly reflected in that the board thickness of a rigid area is asymmetric, so that the asymmetric rigid-flex printed circuit board has a remarkable advantage in the application of connecting different ports at a client terminal.

Aiming at the manufacture of the asymmetric rigid-flex printed circuit board in the prior art, the conventional method is to manufacture the whole board into a structure with the thickness of an auxiliary board, drill holes, weld resist and surface treatment are carried out at the position of the auxiliary board, and then circuit manufacture is carried out at the position of a main board; and then, pressing the whole board into the thickness of the main board, and manufacturing the outer layer of the main board according to the manufacturing process of the common rigid-flex board.

The traditional method comprises the following processes:

pressing the auxiliary board according to the thickness of the auxiliary board → drilling the position of the auxiliary board → perforating → light imaging → manufacturing the circuits of the inner layer of the main board and the outer layer of the auxiliary board → welding the characters → surface processing → blackening and pressing;

pressing the main board according to the thickness of the main board → drilling the main board position → perforating → light imaging → making the circuit on the outer layer of the main board → welding the solder → character → surface processing → controlling the leakage of the large cover from the sub-board → controlling the leakage of the small cover from the large cover → contour processing → normal post-processing.

The asymmetric rigid-flex printed circuit board is manufactured according to the traditional manufacturing process, but the situation that the auxiliary board is not positioned on the outer layer of the main board and the auxiliary board is positioned at the same level as the main board, namely the situation that the auxiliary board is positioned on the outer layer, cannot be manufactured;

the blind slot design is also one of the conventional product types of the printed circuit board, and is mainly used for mounting components or fixing products, so that the overall integration level of the products is improved or the signal shielding effect is achieved. According to the traditional lamination glue blocking process of the blind slot printed circuit board, PP glue flowing is prevented by means of glue blocking materials, so that no glue overflowing exists at the bottom of the blind slot.

The conventional blind groove design to the rigid-flex printed circuit board is common in the industry, but for the condition that the flexible section is overlapped with the blind groove, the blind groove is designed in the asymmetric rigid-flex printed circuit board, the industry has no manufacturing method, the design is usually a high-integration line end, the product design structure is complex, and the manufacturing difficulty in the industry is high.

In view of the above situation, it is desirable to provide a process method for conveniently manufacturing a rigid-flex printed circuit board with an asymmetric outer-layer auxiliary plate having a blind groove coinciding with a flexible plate.

Disclosure of Invention

The invention mainly aims to provide a method for conveniently manufacturing an asymmetric outer-layer auxiliary plate rigid-flexible combined plate with blind grooves superposed with a flexible plate.

In order to achieve the main purpose, the manufacturing method of the asymmetric rigid-flex printed circuit board provided by the invention comprises the steps of S1, manufacturing blind holes of the rigid-flex main board, manufacturing graphs on the daughter board, pre-controlling depth, sticking a high-temperature polyimide adhesive tape for blocking adhesive, drilling the first layer to the fourth layer, and manufacturing rear holes according to resin plug holes;

s2, making holes in the rigid-flex auxiliary plate, making patterns on the fourth layer and the fifth layer, pasting a glue blocking and filling adhesive tape on the fifth layer, laminating the first to sixth layers of rigid-flex plates, and drilling the first to sixth layers of rigid-flex plates;

s3, manufacturing a blind groove plate, and laminating the seventh layer to the tenth layer;

s4, performing primary pressing, namely pressing the first to tenth layers, filling a glue blocking material in the blind groove, adding a PI filling adhesive tape into the inner layer cavity, and performing primary pressing on the first to tenth layers;

s5, secondary pressing, manufacturing an outer layer through hole, and performing secondary pressing on the first to tenth layers;

and S6, opening the outer layer, and taking out the glue blocking material.

According to the scheme, the asymmetric outer-layer auxiliary plate rigid-flexible combined plate with the blind groove coincident with the flexible plate is disassembled into the rigid-flexible part and the blind groove part, the complex structure is disassembled into two common processes to be respectively realized, the holes of the blind groove section, the holes of the rigid-flexible main plate and the holes of the rigid-flexible auxiliary plate are respectively manufactured, the process is simplified, and the control process difficulty is effectively reduced.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The manufacturing method of the asymmetric rigid-flex printed circuit board comprises the steps of S1, manufacturing blind holes of a rigid-flex main board, manufacturing graphs on a sub board, pre-controlling depth, sticking a high-temperature polyimide adhesive tape for blocking adhesive, drilling the first layer to the fourth layer, and manufacturing rear holes according to resin plug holes;

s2, making holes in the rigid-flex auxiliary plate, making patterns on the fourth layer and the fifth layer, pasting a glue blocking and filling adhesive tape on the fifth layer, laminating the first to sixth layers of rigid-flex plates, and drilling the first to sixth layers of rigid-flex plates;

s3, manufacturing a blind groove plate, and laminating the seventh layer to the tenth layer;

s4, performing primary pressing, namely pressing the first to tenth layers, filling a glue blocking material in the blind groove, adding a PI filling adhesive tape into the inner layer cavity, and performing primary pressing on the first to tenth layers;

s5, secondary pressing, manufacturing an outer layer through hole, and performing secondary pressing on the first to tenth layers;

and S6, opening the outer layer, and taking out the glue blocking material.

And (5) taking the rigid-flex main board obtained after the step S1 as an inner core board.

In step S2, a blackening process is performed before the cover is opened.

In step S3, the blind groove is made of a glue blocking material to avoid glue overflow.

In the step S3, the blind slot plate and the rigid-flex plate are subjected to hole milling.

In step S3, patterns of the sixth layer and the seventh layer are produced, and a step is milled so that the rigid-flex board is not raised when pressed.

The blind groove plate and the rigid-flex plate are consistent in size.

And the glue blocking material in the blind groove adopts sectional materials to block glue.

The pressing of the blind groove plate and the pressing of the rigid flexible plate are carried out in the same press.

If the holes of the first to the sixth layers are not plugged, an outer layer adhesive tape is needed to be used for sealing the holes on the surface 1 (by the outer layer adhesive tape) when the first to the ten layers are pressed, and then the adhesive tape is needed to be pasted and torn at the position of the hole according to the mode of the air holes in the process.

The design of the blind groove needs to have part of the glue leaking out of the plate (function needs), and the glue material in the groove adopts sectional material to resist the glue.

Pressing 1-10 layers, and ensuring 10-20 mil of inward shrinkage at the position close to the blind groove for controlling glue overflow.

Aiming at the pressing condition with a blind groove, a double-sided silica gel covering mode is needed for manufacturing.

The technical scheme can be used for manufacturing the asymmetric rigid-flex printed circuit board with the blind slot with the pattern at the bottom.

The auxiliary board and the main board are not in the same level, i.e. one side of the auxiliary board is on the outer layer

The blind slot position has an overlapping portion with the flexible segment.

The glue blocking material in the blind groove is conveniently taken out by adopting multi-section glue blocking

The asymmetric outer-layer auxiliary plate rigid-flexible combined plate with the blind groove coincident with the flexible plate is disassembled into a rigid-flexible part and a blind groove part, the complex structure is disassembled into two common processes to be realized respectively, and holes of the blind groove section, the rigid-flexible main plate and the rigid-flexible auxiliary plate are manufactured respectively, so that the process is simplified, the control process difficulty is effectively reduced, and the following advantages are brought;

simple in preparation

Different from the situation of adopting laser ablation, the glue blocking material divided into multiple sections is adopted, so that the difficulty in taking out the glue blocking material can be effectively reduced;

high applicability

The method can be used for the condition that whether the auxiliary plate is plugged or not, can be manufactured by adopting different schemes under different conditions, and is suitable for manufacturing structures under various conditions.

The asymmetric rigid-flex printed circuit board can be provided with blind grooves and a stepped circuit layer, so that the circuit board is three-dimensional, the optimized assembly space is realized, the performance is stronger, and the asymmetric rigid-flex printed circuit board is widely applied to many fields. For blind groove type plates with higher service environment temperature, blind grooves with larger contact surfaces can be designed to ensure heat dissipation, or a copper-buried mode is adopted to ensure heat dissipation.

The copper-embedded block type circuit board and the blind slot circuit board belong to different manufacturing processes in the circuit board industry respectively, actual methods of the structures are greatly different from each other, and key procedures are different in pressing modes and different in copper embedding modes.

The copper embedding process is divided into a through copper block and a semi-embedded copper block according to the position of the copper block on a circuit board, and can be divided into three conditions according to the combination with a blind slot: a through type and blind slot structure; semi-buried and blind groove structures; the semi-buried type and the blind groove structure are formed by intersecting the blind groove and the copper block.

The manufacturing method of the penetrating type and blind groove structure comprises the following steps:

a first core plate: cutting material → internal light imaging → punching → internal layer etching inspection → hole milling (blind groove milling position) → hole milling once (copper block milling position) → mating center → blackening;

a second core board: cutting material → inner light imaging → punching → inner layer etching inspection → outer light imaging → gold plating (carrying out the plating of a thick gold protective pattern on the bottom of a blind groove) → alkaline etching → one time of hole milling (copper block milling position) → matching center → blackening;

prepreg preparation: cutting → hole milling (the glue is required to be ensured to be capable of filling the copper block nesting requirement and is determined according to the size of the copper block) → matching center;

note: and (3) milling the hole corresponding to the copper block once, wherein the size of the milled hole is 0.1mm (4 mil) larger than the single side of the copper block.

The manufacturing method of the semi-buried and blind groove structure comprises the following steps:

an outer core plate: cutting → pasting the adhesive tape → milling the hole → browning;

an inner side core plate: laminating → tearing tape → ceramic grinding plate → tool matching → internal light imaging → punching → internal layer etching inspection → hole milling (milling blind groove position) → one time of hole milling (copper block position milling) → matching center → blackening;

note: and (4) milling the hole corresponding to the copper block once, wherein the size of the milled hole is 0.1mm larger than the single side of the copper block.

The method comprises the steps of firstly manufacturing the copper-embedded core plate, then realizing the blind groove method, and referring to the normal blind groove method in the subsequent method. The method can be used for manufacturing multilayer blind grooves and copper embedding, has wide application range, but is long in process consumption and not suitable for batch production, so that the method can be improved as follows:

and (4) milling holes on the core plate pressed with the copper blocks, wherein the positions of the milled holes (milled blind grooves) and the positions of the milled edges close to the copper blocks are required to be changed into small knife milling, and the moving speed of a milling cutter is reduced.

Plating thick gold on the bottom of the blind groove of the second core plate to protect the pattern; PP hole milling needs to ensure that glue can be filled into the copper block required by nesting, and hole milling is not carried out on the position, corresponding to the P piece, of the copper block according to the size of the copper block so as to ensure that the glue filled under the copper block is sufficient. During lamination, the laminated plate is made of glue-blocking materials, needs to be different from the conventional blind groove manufacturing, needs to be as close to the depth of the blind groove as possible, and is not suitable to be too thick; the blind groove surface is coated by single-side large silica gel.

The method for simultaneously laminating the copper block and the blind groove plate comprises the following steps:

and respectively manufacturing a first core board and a second core board, and pressing after blackening is finished. Cutting the prepreg, and milling holes to ensure that the glue can be used for filling the copper block nesting; and (4) milling the hole corresponding to the copper block once, wherein the size of the milled hole is 0.1mm larger than the single side of the copper block.

The manufacturing method for the intersection of the blind groove and the copper block comprises the following steps:

a first core plate: cutting material → internal light imaging → punching → internal layer etching inspection → hole milling once (copper block milling position) → matching center → blackening;

a second core board: cutting → internal light imaging → punching → internal layer etching inspection → matching center → blackening;

prepreg preparation: cutting → hole milling (the glue is required to be ensured to be capable of filling the copper block nesting requirement and is determined according to the size of the copper block) → matching center;

outer layer: laminating → ceramic grinding plate → inner light imaging → … → outer light imaging → copper tin plating → milling blind groove → alkaline etching → AOI → milling blind groove → subsequent process.

Note: and (4) milling the hole corresponding to the copper block once, wherein the size of the milled hole is 4mil larger than the single side of the copper block.

Finally, it should be emphasized that the present invention is not limited to the above-described embodiments, but only the preferred embodiments of the invention have been described above, and the present invention is not limited to the above-described embodiments, and any modifications, equivalent substitutions, improvements, etc. within the spirit and principle of the present invention should be included in the protection scope of the present invention.