阅读说明：本技术 多层线路板及其制备方法 (Multilayer circuit board and preparation method thereof ) 是由 李继林 金辉堂 黄振才 王爱林 于 2021-08-02 设计创作，主要内容包括：本申请提供一种多层线路板及其制备方法。上述的多层线路板包括绝缘遮光件、第一结合板和第二结合板。第一结合板上设置有第一裸铜区。第二结合板上设置有第二裸铜区,绝缘遮光件夹设于第一结合板与第二结合板之间,且第一裸铜区在第二结合板的投影与第二裸铜区至少存在部分重叠区域,绝缘遮光件在第二结合板的投影与重叠区域重叠。上述的多层线路板较好地改善了多层线路板的开窗区域出现焊盘显影不彻底的情况,进而提高多层线路板生产效率和能降低多层线路板生产成本。(The application provides a multilayer circuit board and a preparation method thereof. The multilayer circuit board comprises an insulating shading part, a first combination board and a second combination board. The first bonding board is provided with a first bare copper area. The second combination board is provided with a second bare copper area, the insulating light shading piece is clamped between the first combination board and the second combination board, the projection of the first bare copper area on the second combination board at least has a partial overlapping area with the second bare copper area, and the projection of the insulating light shading piece on the second combination board overlaps with the overlapping area. The multilayer circuit board can better improve the condition that the pad is not developed completely in the windowing area of the multilayer circuit board, thereby improving the production efficiency of the multilayer circuit board and reducing the production cost of the multilayer circuit board.)

1. A multilayer wiring board, comprising:

an insulating light shielding member;

the first bonding plate is provided with a first bare copper area;

the second combines the board, be provided with the naked copper district of second on the second combines the board, insulating light-shielding member presss from both sides and locates first combination board with between the second combination board, just first naked copper district in the projection of second combination board with there is partial overlap area at least in the naked copper district of second, insulating light-shielding member is in the projection of second combination board with overlap area overlaps.

2. The multilayer circuit board of claim 1, wherein the insulating light shielding member comprises an insulating covering sleeve and a metal sheet, the insulating covering sleeve is sleeved on the outer wall of the metal sheet, and the insulating metal sleeve is connected with the first combination board and the second combination board respectively.

3. The multilayer wiring board of claim 2, wherein the metal sheet is copper foil.

4. The multilayer wiring board of claim 1, wherein the first bare copper region comprises a first optical anchor point and a first non-copper clad region formed after the etching of the traces.

5. The multilayer wiring board of claim 1, wherein the second bare copper region comprises a second optical anchor point and a second copper free region formed after the circuit has been etched.

6. A method for producing a multilayer wiring board, which is used for producing the multilayer wiring board according to any one of claims 1 to 5, comprising the steps of:

providing a first combination plate and a second combination plate;

acquiring position information of the first bare copper area and the second bare copper area;

according to the position information of the first bare copper area and the second bare copper area, respectively carrying out shading treatment on the first combination board and the second combination board by adopting an insulating shading piece, so that the insulating shading piece is correspondingly arranged at the overlapping part of the first bare copper area and the second bare copper area;

carrying out pressing operation on the first combination plate and the second combination plate so that the insulating shading sheet is clamped between the first combination plate and the second combination plate to obtain a multilayer circuit board semi-finished product;

and carrying out exposure and development operation on the semi-finished product of the multilayer circuit board to obtain the multilayer circuit board.

7. The method of manufacturing a multilayer wiring board according to claim 6, wherein before the step of subjecting the semifinished multilayer wiring board to the exposure and development operation and after the step of subjecting the first bonding board and the second bonding board to the bonding operation, the method of manufacturing a multilayer wiring board further comprises the steps of:

coarsening the semi-finished product of the multilayer circuit board to coarsen the board surface of the semi-finished product of the multilayer circuit board;

and carrying out ink printing operation on the coarsened semi-finished product of the multilayer circuit board so as to enable the ink to cover the board surface of the coarsened semi-finished product of the multilayer circuit board.

8. The method of manufacturing a multilayer wiring board according to claim 6, wherein the exposing and developing operation of the semifinished multilayer wiring board comprises the steps of:

carrying out alignment fixing treatment on the multilayer circuit board semi-finished product by adopting a film;

exposing the multi-layer circuit board semi-finished product subjected to the alignment treatment;

and developing the semi-finished product of the exposed multilayer circuit board.

9. The method of manufacturing a multilayer wiring board according to claim 8, wherein after the step of subjecting the semi-finished multilayer wiring board to the development operation, the step of subjecting the semi-finished multilayer wiring board to the exposure development operation further comprises the steps of:

and (4) performing curium plate operation on the developed multi-layer circuit board semi-finished product.

10. The method for manufacturing a multilayer circuit board according to any one of claims 6 to 9, wherein the first bonding board and the second bonding board are subjected to a pressing operation using a prepreg.

Technical Field

The invention relates to the technical field of circuit board processing, in particular to a multilayer circuit board and a preparation method thereof.

Background

In the processing and production of the circuit board, the implementation object of the solder mask process is the circuit board with the circuit manufactured, most of the processing and preparation of the circuit board are completed before the solder mask process is carried out, and in the assembly welding process of the circuit board, the two opposite side surfaces of the circuit board need to be subjected to ink printing, and then the inks on the two opposite side surfaces of the circuit board need to be exposed and developed respectively.

However, when the ink on one side of the circuit board is exposed, the exposure energy is large, which easily causes the unnecessary cured ink on the windowing area on the other opposite side to be photo-cured, and further causes the problem that the pad development is not complete in the windowing area of the circuit board during development. If the problem that the pad is not developed completely in the windowing area of the circuit board is solved by reducing the exposure energy, the problems of oil falling and oil bridge falling in the solder mask area can be caused; if one side of the circuit board is firstly subjected to ink printing, the ink on the side is exposed, then the other opposite side of the circuit board is subjected to ink printing, and the ink on the side is exposed, the processing and preparation period of the circuit board is prolonged, the preparation efficiency of the circuit board is reduced, and the preparation cost of the circuit board is increased.

Disclosure of Invention

The invention aims to overcome the defects in the prior art, and provides a preparation method of a multilayer circuit board and the multilayer circuit board, wherein the condition that a pad is not developed completely in a windowing area of the circuit board can be improved, the production efficiency of the circuit board can be improved, and the production cost of the circuit board can be reduced.

The purpose of the invention is realized by the following technical scheme:

a multilayer wiring board comprising:

an insulating light shielding member;

the first bonding plate is provided with a first bare copper area;

the second combines the board, be provided with the naked copper district of second on the second combines the board, insulating light-shielding member presss from both sides and locates first combination board with between the second combination board, just first naked copper district in the projection of second combination board with there is partial overlap area at least in the naked copper district of second, insulating light-shielding member is in the projection of second combination board with overlap area overlaps.

In one embodiment, the insulating light-shielding member includes an insulating covering sleeve and a metal sheet, the insulating covering sleeve is sleeved on an outer wall of the metal sheet, and the insulating metal sleeve is connected with the first combination plate and the second combination plate respectively.

In one embodiment, the metal sheet is a copper foil.

In one embodiment, the first bare copper region comprises a first optical anchor point and a first non-copper-clad region formed after the line etching.

In one embodiment, the second bare copper region comprises a second optical anchor point and a second copper-free region formed after the line etching.

A method of manufacturing a multilayer wiring board for use in manufacturing a multilayer wiring board according to any one of the above embodiments, comprising the steps of:

providing a first combination plate and a second combination plate;

acquiring position information of the first bare copper area and the second bare copper area;

according to the position information of the first bare copper area and the second bare copper area, respectively carrying out shading treatment on the first combination board and the second combination board by adopting an insulating shading piece, so that the insulating shading piece is correspondingly arranged at the overlapping part of the first bare copper area and the second bare copper area;

carrying out pressing operation on the first combination plate and the second combination plate so that the insulating shading sheet is clamped between the first combination plate and the second combination plate to obtain a multilayer circuit board semi-finished product;

and carrying out exposure and development operation on the semi-finished product of the multilayer circuit board to obtain the multilayer circuit board.

In one embodiment, before the step of performing the exposure and development operation on the semi-finished product of the multilayer circuit board, and after the step of performing the pressing operation on the first bonding board and the second bonding board, the method for manufacturing the multilayer circuit board further comprises the following steps:

coarsening the semi-finished product of the multilayer circuit board to coarsen the board surface of the semi-finished product of the multilayer circuit board;

and carrying out ink printing operation on the coarsened semi-finished product of the multilayer circuit board so as to enable the ink to cover the board surface of the coarsened semi-finished product of the multilayer circuit board.

In one embodiment, the exposing and developing operation performed on the semi-finished product of the multilayer circuit board comprises the following steps:

carrying out alignment fixing treatment on the multilayer circuit board semi-finished product by adopting a film;

exposing the multi-layer circuit board semi-finished product subjected to the alignment treatment;

and developing the semi-finished product of the exposed multilayer circuit board.

In one embodiment, after the step of performing the developing operation on the exposed semi-finished product of the multilayer circuit board, the step of performing the exposing and developing operation on the semi-finished product of the multilayer circuit board further includes the following steps:

and (4) performing curium plate operation on the developed multi-layer circuit board semi-finished product.

In one embodiment, a prepreg is used to perform a pressing operation on the first bonding board and the second bonding board.

Compared with the prior art, the invention has at least the following advantages:

in the multilayer wiring board of the present invention, an insulating light-shielding member is interposed between a first bonding plate and a second bonding plate, and the insulating light-shielding member is correspondingly arranged at the overlapping position of the first bare copper area of the first combination board and the second bare copper area of the second combination board, the insulating shading piece can better shade the parts without shading materials on the first combination plate and the second combination plate, and the insulating shading piece can reduce the possibility that when the printing ink on one side surface of the circuit board is exposed, the undesirably cured ink in the windowed area on the other opposing side is also photocured due to the greater exposure energy, therefore, the problem of incomplete development of the bonding pads in the windowing area of the circuit board during development is solved, the condition of incomplete development of the bonding pads in the windowing area of the multilayer circuit board is well improved, the production efficiency of the multilayer circuit board is improved, and the production cost of the multilayer circuit board can be reduced.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a cross-sectional view of a multilayer wiring board according to an embodiment of the present invention;

fig. 2 is a flowchart of a method for manufacturing a multilayer wiring board according to an embodiment of the present invention.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not represent the only embodiments.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The present application provides a multilayer wiring board. Referring to fig. 1, a multilayer circuit board according to an embodiment includes an insulating light shielding member 100, a first bonding board 200, and a second bonding board 300. The first bonding board 200 has a first bare copper area 210 disposed thereon. The second bonding board 300 is provided with a second bare copper region 310. The insulating light-shielding member 100 is sandwiched between the first combination board 200 and the second combination board 300, and the insulating light-shielding member 10 is disposed corresponding to the first bare copper area 210 and the second bare copper area 310, respectively, that is, a projection area of the insulating light-shielding member 100 on the second combination board 300 is smaller than, larger than or equal to an area of the second bare copper area 310, and at least a part of the projection area of the insulating light-shielding member 100 on the second combination board 300 is overlapped with the second bare copper area 310. In the present embodiment, the first bare copper region 210 and the second bare copper region 310 are disposed correspondingly, and the projection of the first bare copper region 3101 on the second bonding board 300 at least partially overlaps the second bare copper region 310, so that the insulating light-shielding member 100 is reliably sandwiched between the first bonding board 200 and the second bonding board 300.

In the multilayer wiring board, the insulating light-shielding member 100 is interposed between the first bonding plate 200 and the second bonding plate 300, and such that the insulating light-shielding member 100 is correspondingly disposed at the overlapping of the first bare copper area 210 of the first bonding plate 200 and the second bare copper area 310 of the second bonding plate 300, the insulating light-shielding member 100 can better shield the parts without light-shielding materials on the first combination board 200 and the second combination board 300, thereby reducing the possibility that when the ink on one side surface of the circuit board is exposed, the undesirably cured ink in the windowed area on the other opposing side is also photocured due to the greater exposure energy, therefore, the problem of incomplete development of the bonding pads in the windowing area of the circuit board during development is solved, the condition of incomplete development of the bonding pads in the windowing area of the multilayer circuit board is well improved, the production efficiency of the multilayer circuit board is improved, and the production cost of the multilayer circuit board can be reduced.

It can be understood that, on the multilayer circuit board, the surface of each layer of circuit board is covered with copper foil, the copper foil is a copper-clad layer etched by a circuit, each layer of circuit board in the multilayer circuit board has a part which is not covered with copper layer after etching the circuit and at least an outermost layer has optical positioning points, namely a first bare copper area of a first combination board and a second bare copper area of a second combination board, if the areas of each layer of circuit board which is not covered with copper layer are overlapped, the shading effect of the overlapped areas is poor, so that when the ink on one side of the multilayer circuit board is exposed, the exposure energy is large, the unnecessary solidified ink on the windowing area on the other opposite side is also solidified by light, and the problem that the pad is not complete appears in the windowing area of the circuit board during development, therefore, in the application, the insulating piece is correspondingly arranged at the overlapped part of the first bare copper area and the second bare copper area, the insulating shading piece can better shield the parts without shading materials on the first combination plate and the second combination plate, the condition that the development of a bonding pad is not complete in a windowing area of the multilayer circuit board is better improved, the production efficiency of the multilayer circuit board is further improved, and the production cost of the multilayer circuit board can be reduced.

It can be understood that, both sides of the light-transmitting substrate of the circuit board are not covered by light-blocking materials, and an oil-blocking surface is added to the windowing region of the windowing surface of one side of the light-transmitting substrate, which needs to be windowed and the other side needs to be printed with a solder resist, so that in the exposure and development process, even if the exposure energy is large and the ink of the windowing region on the other side needs to be windowed is cured, the windowing region at the oil-blocking surface can be completely developed through the oil-blocking surface of the windowing region, but in the above situation, the windowing region outside the oil-blocking surface may be subjected to the effect of energy light scattering, so that the ink at the periphery of the oil-blocking surface of the windowing region is cured, and further the windowing region of the multilayer circuit board has incomplete pad development, if the size of the oil-blocking surface is further adjusted according to the windowing region which actually generates ghost, the windowing region range which actually generates ghost is changed due to the small difference of the exposure energy, the size of the oil blocking surface of the windowing area of the multilayer circuit board is difficult to adjust in the actual exposure and development process, the exposure and development difficulty of the multilayer circuit board is increased, and then the preparation efficiency of the multilayer circuit board is reduced and the preparation cost of the multilayer circuit board is improved.

The insulating metal part is a structural part with metal light blocking function and insulating function, so that the insulating property of the insulating metal part is ensured, the problem of short circuit of a circuit of the multilayer circuit board caused by contact of the insulating metal part and the circuit on the multilayer circuit board is avoided, and the light blocking property of the insulating metal part is ensured, so that the problem of incomplete pad development in a windowing region of the multilayer circuit board in the exposure and development process of the multilayer circuit board is solved.

In one embodiment, the insulating light shading part comprises an insulating coating sleeve and a metal sheet, the insulating coating sleeve is sleeved on the outer wall of the metal sheet, and the insulating metal sleeve is connected with the first combination plate and the second combination plate respectively. The insulating metal piece is directly contacted with the first combination plate or the second combination plate, so that the insulativity of the insulating metal piece and the circuit board of the circuit board is ensured, the metal piece is sleeved in the insulating coating sleeve, the light-shielding property of the insulating metal piece is ensured, the combined use of the insulating coating sleeve and the metal piece effectively improves the condition that the pad development is incomplete in the windowing region of the multilayer circuit board, the production efficiency of the multilayer circuit board is improved, and the production cost of the multilayer circuit board is reduced.

In one embodiment, the metal sheet is a copper foil, so that the light shielding performance of the insulating metal sheet is ensured, the insulating metal sheet is further ensured to effectively improve the condition that the development of a bonding pad is not complete in a windowing area of the multilayer circuit board, the production efficiency of the multilayer circuit board is further improved, and the production cost of the multilayer circuit board is reduced.

In one embodiment, the projection of the first bare copper area on the second bonding board and the overlapping part of the second bare copper area coincide with the projection of the metal sheet of the insulating light shielding member on the second bonding board. It can be understood that the overlapping portion of the projection of the first bare copper area on the second bonding board and the second bare copper area is the overlapping projection portion of the first bare copper area on the projection of the second bonding board and the second bare copper area, namely the projection a, the outer periphery of the projection of the metal sheet of the insulating light-shielding member on the second bonding board coincides with the outer periphery of the projection a, so as to ensure that the insulating light-shielding member better shields the portions without light-shielding material on the first bonding board and the second bonding board, and alleviate the problem that when the ink on one side surface of the circuit board is exposed, the exposure energy is large, the unwanted solidified ink in the windowing area on the other opposite side surface is easily photo-solidified, and further the problem that the development of the bonding pad is not complete in the windowing area of the circuit board during development is solved, and the problem that the development of the bonding pad is not complete in the windowing area of the multilayer circuit board is improved well, and then improve multilayer circuit board production efficiency and can reduce multilayer circuit board manufacturing cost, in addition, avoided a plurality of driling of multilayer circuit board to be located insulating metal piece department, and then caused insulating metal piece and the heavy copper formation route of the hole metallization of drilling, and then influenced multilayer circuit board line connection problem, reduced insulating metal piece promptly to the influence of the line connection of multilayer circuit board, and then ensured multilayer circuit board's safety in utilization.

In one embodiment, the insulation cover is a prepreg insulation cover. It can be understood that when the first combination board and the second combination board are pressed, the prepreg is adopted to effectively ensure the insulativity of the first combination board and the second combination board and the pressing firmness of the insulating light shading piece, thereby ensuring the structural stability of the multilayer circuit board, leading the insulating coating sleeve to be a prepreg insulating coating sleeve, namely, the insulating covering sleeve is made of prepreg material, so that the pressing firmness of the first combination board and the second combination board on the insulating shading piece in the pressing process is enhanced, the deviation of the insulating shading piece is effectively reduced, further ensuring the shielding of the insulating shading part to the parts without shading materials on the first combination board and the second combination board, better improving the condition that the development of the bonding pad is not complete in the windowing area of the multilayer circuit board, improving the production efficiency of the multilayer circuit board and reducing the production cost of the multilayer circuit board.

In one embodiment, the insulating light shielding member further includes an adhesive layer disposed on an outer wall of the insulating covering sleeve, and the adhesive layer is located on two opposite sides of the metal sheet. It can be understood that, in the process of pressing the first combination board and the second combination board, the first combination board, the insulating light-shading part and the second combination board need to be sequentially stacked, and then the pressing board is used for pressing, during which, at the moment when the pressing board is pressed down, the pressing board has a thrust force on the first combination board, the insulating light-shading part and the second combination board, the thrust force easily causes the insulating light-shading part to generate relative movement relative to the first combination board and the second combination board, and further causes the light-shading effect of the insulating light-shading plate to be reduced, therefore, in the application, the adhesive layers are arranged on the outer wall of the insulating covering sleeve, and the adhesive layers are arranged on the two opposite sides of the metal sheet, so that the insulating light-shading part respectively has adhesive strength with the first combination board and the second combination board, and the relative movement of the insulating light-shading part relative to the first combination board and the second combination board is improved, therefore, the problem of reduction of the shading effect of the insulating shading plate is caused, the condition that the development of the bonding pad is not complete in the windowing area of the multilayer circuit board is well improved, the production efficiency of the multilayer circuit board is improved, and the production cost of the multilayer circuit board can be reduced.

In one embodiment, the first bare copper area comprises a first optical positioning point and a first copper-uncovered area formed after circuit etching, the first copper-uncovered area formed after circuit etching is a circuit board part covered with a copper layer before circuit etching is not carried out, and the circuit board part covered with the copper layer is not covered with the copper layer after circuit etching is carried out. It can be understood that the area on the multilayer circuit board, in which the development failure of the windowing area is likely to occur, is the area without copper coating formed after the etching of the optical positioning point and the circuit, so that the first optical positioning point of the first combination board and the first area without copper coating formed after the etching of the circuit are selected to be shielded by the insulating light-shielding sheet, the condition that the development failure of the bonding pad occurs in the windowing area of the multilayer circuit board is effectively improved, the production efficiency of the multilayer circuit board is further improved, and the production cost of the multilayer circuit board can be reduced.

In one embodiment, the second bare copper area comprises a second optical positioning point and a second copper-uncovered area formed after circuit etching, the second copper-uncovered area formed after circuit etching is a circuit board part covered with a copper layer before circuit etching is not carried out, and the circuit board part covered with the copper layer is not covered with the copper layer after circuit etching is carried out. It can be understood that the area on the multilayer circuit board, in which the development failure of the windowing area is likely to occur, is the area where the optical positioning point and the circuit are etched to form the area without copper cladding, so that the second optical positioning point of the second combination board and the area where the circuit is etched to form the area without copper cladding are selected to be shielded by the insulating light shielding sheet, the condition that the development failure of the bonding pad occurs in the windowing area of the multilayer circuit board is effectively improved, the production efficiency of the multilayer circuit board is improved, and the production cost of the multilayer circuit board is reduced.

The application also provides a preparation method of the multilayer circuit board, which is used for preparing the multilayer circuit board of any embodiment. Further, the preparation method of the multilayer circuit board comprises the following steps: providing a first combination plate and a second combination plate; acquiring position information of the first bare copper area and the second bare copper area; according to the position information of the first bare copper area and the second bare copper area, respectively carrying out shading treatment on the first combination board and the second combination board by using an insulating shading piece, so that the insulating shading piece is correspondingly arranged at the overlapping part of the first bare copper area and the second bare copper area; carrying out pressing operation on the first combination plate and the second combination plate so that the insulating shading sheet is clamped between the first combination plate and the second combination plate to obtain a semi-finished product of the multilayer circuit board; and carrying out exposure and development operation on the semi-finished product of the multilayer circuit board to obtain the multilayer circuit board.

In the preparation method of the multilayer circuit board, the first combination board and the second combination board are shielded by adopting the insulating light-shielding piece according to the position information of the first bare copper area and the second bare copper area, so that the insulating light-shielding piece is correspondingly arranged at the superposition position of the first bare copper area and the second bare copper area, and the first combination board and the second combination board are pressed, so that the insulating light-shielding piece is clamped between the first combination board and the second combination board, the part of the insulating light-shielding piece, which is not provided with the light-shielding material, on the first combination board and the second combination board is better shielded, after the exposure and development operation of the semi-finished product of the multilayer circuit board, the probability of incomplete pad development is reduced, the photo-curing of the cured ink, which is not needed for the windowing area, on one side surface of the circuit board is easily caused when the ink on the other side surface is exposed, the exposure energy is larger, and the photo-curing of the cured ink, which is not needed for the windowing area, is easily caused on the other side surface, therefore, the problem of incomplete development of the bonding pads in the windowing area of the circuit board during development is solved, the condition of incomplete development of the bonding pads in the windowing area of the multilayer circuit board is well improved, the production efficiency of the multilayer circuit board is improved, and the production cost of the multilayer circuit board can be reduced.

Referring to fig. 2, in order to better understand the method for manufacturing a multilayer circuit board of the present application, the method for manufacturing a multilayer circuit board of the present application is further explained below, and the method for manufacturing a multilayer circuit board includes the following steps:

and S100, providing a first combination plate and a second combination plate. It is understood that the first bonding board is a wiring board having a multilayer wiring. And assuming that the number of layers of the multilayer circuit board is m and the number of layers of the first combination board is n, the number of layers of the second combination board is m-n, wherein m is an integer greater than or equal to 2, n is an integer greater than or equal to 1, and m is greater than n. The first combination plate and the second combination plate are pressed to form a multi-layer circuit board semi-finished product, and the arrangement feasibility of the insulated metal sheet is ensured.

S200, acquiring the position information of the first bare copper area and the second bare copper area. It is understood that the first bare copper area is the area of the first bonding board where no copper is coated, the second bare copper area is the area of the second bonding board where no copper is coated, the position information of the first bare copper area and the second bare copper area can be obtained according to the design of the film and the optical positioning point of the circuit board, the judgment accuracy of the part without shading materials on the multilayer circuit board is ensured, thereby ensuring that the insulating metal sheet effectively shields the part without shading materials on the multilayer circuit board, thereby reducing the problem that when the ink on one side surface of the circuit board is exposed, the exposure energy is larger, the unnecessary solidified ink on the windowing area on the other opposite side surface is easy to be photo-solidified, therefore, the problem of incomplete development of the bonding pads in the windowing area of the circuit board during development is solved, the condition of incomplete development of the bonding pads in the windowing area of the multilayer circuit board is well improved, the production efficiency of the multilayer circuit board is improved, and the production cost of the multilayer circuit board can be reduced.

S300, according to the position information of the first bare copper area and the second bare copper area, shading treatment is respectively carried out on the first combination plate and the second combination plate by adopting an insulating shading piece, so that the insulating shading piece is correspondingly arranged at the overlapping position of the first bare copper area and the second bare copper area. The insulating light-shielding part is correspondingly arranged at the superposition position of the first bare copper area and the second bare copper area, so that the parts without light-shielding materials on the first combination board and the second combination board of the insulating light-shielding part are shielded well, the probability of incomplete pad development is reduced after the semi-finished product of the multilayer circuit board is exposed and developed, the problems that exposure energy is high when ink on one side surface of the circuit board is exposed, the solidified ink which is not needed in the windowing area on the other opposite side surface is easy to be cured by light, and the incomplete pad development is caused in the windowing area of the circuit board during development are solved, the condition that the incomplete pad development is caused in the windowing area of the multilayer circuit board is well improved, the production efficiency of the multilayer circuit board is improved, and the production cost of the multilayer circuit board is reduced.

And S400, carrying out pressing operation on the first combination plate and the second combination plate so that the insulating shading sheet is clamped between the first combination plate and the second combination plate, and obtaining a multilayer circuit board semi-finished product. It can be understood that carry out the pressfitting operation to first combination board and second combination board to make insulating anti-dazzling screen press from both sides and establish between first combination board and second combination board, ensured insulating sheetmetal's stability that sets up, and reduced insulating sheetmetal to the circuit interference of multilayer circuit board, and then improved multilayer circuit board's safety in utilization.

And S500, carrying out exposure and development operation on the semi-finished product of the multilayer circuit board to obtain the multilayer circuit board. It can be understood that the insulating light-shielding member is adopted to perform light-shielding treatment on the first combination board and the second combination board according to the position information of the first bare copper area and the second bare copper area, so that the insulating light-shielding member is correspondingly arranged at the superposition position of the first bare copper area and the second bare copper area, and the first combination board and the second combination board are subjected to pressing operation, so that the insulating light-shielding sheet is clamped between the first combination board and the second combination board, so that the insulating light-shielding member better shields the energy light penetrating through the parts of the first combination board and the second combination board without light-shielding materials in the exposure and development operation process of the multi-layer circuit board semi-finished product, and further the probability of incomplete development of a bonding pad is reduced after the exposure and development operation of the multi-layer circuit board semi-finished product, thereby reducing the exposure energy when the ink on one side surface of the circuit board is exposed, and easily causing the photocuring of the cured ink on the other side surface which is not required to be opened, therefore, the problem of incomplete development of the bonding pads in the windowing area of the circuit board during development is solved, the condition of incomplete development of the bonding pads in the windowing area of the multilayer circuit board is well improved, the production efficiency of the multilayer circuit board is improved, and the production cost of the multilayer circuit board can be reduced.

In the preparation method of the multilayer circuit board, the first combination board and the second combination board are shielded by adopting the insulating light-shielding piece according to the position information of the first bare copper area and the second bare copper area, so that the insulating light-shielding piece is correspondingly arranged at the superposition position of the first bare copper area and the second bare copper area, and the first combination board and the second combination board are pressed, so that the insulating light-shielding piece is clamped between the first combination board and the second combination board, the part of the insulating light-shielding piece, which is not provided with the light-shielding material, on the first combination board and the second combination board is better shielded, after the exposure and development operation of the semi-finished product of the multilayer circuit board, the probability of incomplete pad development is reduced, the photo-curing of the cured ink, which is not needed for the windowing area, on one side surface of the circuit board is easily caused when the ink on the other side surface is exposed, the exposure energy is larger, and the photo-curing of the cured ink, which is not needed for the windowing area, is easily caused on the other side surface, therefore, the problem of incomplete development of the bonding pads in the windowing area of the circuit board during development is solved, the condition of incomplete development of the bonding pads in the windowing area of the multilayer circuit board is well improved, the production efficiency of the multilayer circuit board is improved, and the production cost of the multilayer circuit board can be reduced.

In one embodiment, before the step of performing the exposure and development operation on the semi-finished product of the multilayer circuit board and after the step of performing the pressing operation on the first bonding board and the second bonding board, the method for manufacturing the multilayer circuit board further comprises the following steps:

and coarsening the semi-finished product of the multilayer circuit board to coarsen the board surface of the semi-finished product of the multilayer circuit board. It can be understood that the coarsening of the plate surface of the multilayer circuit board semi-finished product increases the contact area of the multilayer circuit board semi-finished product and the printing ink, increases the adhesion strength of the printing ink on the surface of the multilayer circuit board semi-finished product, ensures that the printing ink leaked from the screen printing plate to the surface of the multilayer circuit board semi-finished product flows in a large area less, improves the distribution uniformity of the printing ink on the multilayer circuit board semi-finished product, is beneficial to forming a layer with consistent thickness on the multilayer circuit board semi-finished product, reduces the contact between a film solder mask and the printing ink of a solder mask plug hole of the multilayer circuit board and the printing ink on the surface of the multilayer circuit board without covering copper, greatly improves the film printing phenomenon of the multilayer circuit board, and effectively improves the appearance and the quality of the multilayer circuit board.

Further, the coarsened semi-finished product of the multilayer circuit board is subjected to ink printing operation, so that the ink covers the board surface of the coarsened semi-finished product of the multilayer circuit board. It can be understood that the printing ink covers the roughened surface of the multilayer circuit board semi-finished product, the adhesion strength of the printing ink on the surface of the multilayer circuit board semi-finished product is favorably increased, the printing ink which is printed on the surface of the multilayer circuit board semi-finished product through screen printing is less prone to flowing in a large area, the distribution uniformity of the printing ink on the multilayer circuit board semi-finished product is improved, the formation of a solder mask layer with the same thickness on the multilayer circuit board semi-finished product is favorably realized, the contact between the printing ink of a film sheet and a solder mask plug hole of the multilayer circuit board and the printing ink on the surface of the multilayer circuit board, which is not covered with copper, is reduced, the phenomenon of film printing of the multilayer circuit board is greatly improved, and the appearance and the quality of the multilayer circuit board are effectively improved.

In the preparation method of the multilayer circuit board, the surface cleaning operation is carried out on the semi-finished product of the multilayer circuit board, the adhesive strength of the ink and the semi-finished product of the multilayer circuit board is enhanced, so that the ink on the semi-finished product of the multilayer circuit board is uniformly dispersed, the integrality and the stability of a solder mask of the multilayer circuit board are further improved, in addition, because of the existence of the copper-clad circuit on the multi-layer circuit board semi-finished product, the copper-clad circuit on the surface of the multi-layer circuit board semi-finished product is higher than the part which is not clad with copper on the surface of the circuit board to be exposed, namely, the height of the ink on the copper-clad circuit of the multi-layer circuit board semi-finished product after the ink is uniformly printed is higher than that of the ink on the non-copper-clad circuit of the multi-layer circuit board semi-finished product, and further, the contact area between the film and the multilayer circuit board is reduced, the probability of film printing on the multilayer circuit board is reduced, and the quality of the multilayer circuit board is improved.

In one embodiment, the exposure and development operation is performed on the semi-finished product of the multilayer circuit board, and comprises the following steps:

and carrying out alignment fixing treatment on the multilayer circuit board semi-finished product by adopting a film. It can be understood that when the film is adopted to expose and develop the multilayer circuit board semi-finished product, the positioning accuracy of the bonding pad of the multilayer circuit board is improved, so that the multilayer circuit board semi-finished product and the film are aligned and fixed, the bonding pad positioning accuracy of the multilayer circuit board is ensured, and the quality of the multilayer circuit board is improved.

And further, carrying out exposure treatment on the multi-layer circuit board semi-finished product subjected to the alignment treatment. The method can be understood that the semi-finished product of the multilayer circuit board and the film are subjected to exposure treatment after being aligned and fixed, the positioning accuracy of the bonding pad of the multilayer circuit board is ensured, and the quality of the multilayer circuit board is improved.

Furthermore, the semi-finished product of the multi-layer circuit board after exposure treatment is developed, so that the development of the multi-layer circuit board is realized.

In the operation of exposing and developing the multilayer circuit board semi-finished product, when the film is used for exposing and developing the multilayer circuit board semi-finished product, the multilayer circuit board semi-finished product and the film are aligned and fixed, the positioning accuracy of the bonding pad of the multilayer circuit board is improved, and the quality of the multilayer circuit board is further improved.

In one embodiment, before the step of performing the exposure and development operation on the semi-finished multilayer circuit board, and after the step of performing the ink printing operation on the coarsened semi-finished multilayer circuit board, the method for manufacturing a multilayer circuit board further comprises the following steps: and curing the multilayer circuit board semi-finished product. It can be understood that the ink has higher viscosity before being cured, and in the process of exposing and developing the multilayer circuit board semi-finished product by adopting the film, the ink is easily adhered to the film to form the film print.

In one embodiment, after the step of performing the developing operation on the exposed semi-finished product of the multilayer circuit board, the step of performing the exposing and developing operation on the semi-finished product of the multilayer circuit board further includes the following steps: and (4) performing cramping plate operation on the developed multi-layer circuit board semi-finished product. It can be understood that excessive curing of the ink will cause that the ink on the bonding pad cannot be removed by development, therefore, when the multi-layer circuit board semi-finished product is cured, the ink on the multi-layer circuit board semi-finished product is removed preliminarily, the curing degree of the ink on the multi-layer circuit board semi-finished product is low, and the ink of the multi-layer circuit board is easily damaged after colliding.

In one embodiment, the etching solution is used for developing the semi-finished product of the multi-layer circuit board after the exposure treatment, so that the development of the multi-layer circuit board is ensured.

In one embodiment, the prepreg is used for carrying out pressing operation on the first combination plate and the second combination plate, so that the connection stability of the insulating metal piece, the first combination plate and the second combination plate is ensured.

Compared with the prior art, the invention has at least the following advantages:

in the multilayer wiring board of the present invention, an insulating light-shielding member is interposed between a first bonding plate and a second bonding plate, and the insulating light-shielding member is correspondingly arranged at the overlapping position of the first bare copper area of the first combination board and the second bare copper area of the second combination board, the insulating shading piece can better shade the parts without shading materials on the first combination plate and the second combination plate, and the insulating shading piece can reduce the possibility that when the printing ink on one side surface of the circuit board is exposed, the undesirably cured ink in the windowed area on the other opposing side is also photocured due to the greater exposure energy, therefore, the problem of incomplete development of the bonding pads in the windowing area of the circuit board during development is solved, the condition of incomplete development of the bonding pads in the windowing area of the multilayer circuit board is well improved, the production efficiency of the multilayer circuit board is improved, and the production cost of the multilayer circuit board can be reduced.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.