阅读说明：本技术 线路板及其制作方法 (Circuit board and manufacturing method thereof ) 是由 郭国栋 赵一涛 于 2019-08-27 设计创作，主要内容包括：本发明提供一种线路板及其制作方法,所述线路板包括：层叠设置的第一基材及第二基材,其中,所述第一基材上具有靠近所述第二基材的第一金属层；位于所述第一基材上且贯穿部分所述第一金属层的槽体及贯穿所述第二基材及所述第一金属层且连接所述槽体底部的通孔；位于所述通孔内的金属材料；其中,所述第一金属层的厚度为50μm～500μm。以此解决机械钻孔将台阶底部的铜控穿的风险,提高产品质量,降低成本。(The invention provides a circuit board and a manufacturing method thereof, wherein the circuit board comprises: the first base material and the second base material are arranged in a stacked mode, wherein a first metal layer close to the second base material is arranged on the first base material; the groove body is positioned on the first base material and penetrates through part of the first metal layer, and the through hole penetrates through the second base material and the first metal layer and is connected with the bottom of the groove body; a metal material located within the via; wherein the thickness of the first metal layer is 50-500 μm. Therefore, the risk that the copper at the bottom of the step is penetrated by mechanical drilling is solved, the product quality is improved, and the cost is reduced.)

1. A circuit board, comprising:

the first base material and the second base material are arranged in a stacked mode, wherein a first metal layer close to the second base material is arranged on the first base material;

the groove body is positioned on the first base material and penetrates through part of the first metal layer, and the through hole penetrates through the second base material and the first metal layer and is connected with the bottom of the groove body;

a metal material located within the via;

wherein the thickness of the first metal layer is 50-500 μm.

2. The wiring board of claim 1,

the projection of the connection position of the groove body and the through hole in the horizontal direction is positioned in the middle of the first metal layer.

3. The wiring board of claim 2,

the projection of the connection position of the groove body and the through hole in the horizontal direction is 0.01 mm-0.45 mm lower than the surface, away from the second base material, of the first metal layer.

4. The wiring board of claim 1,

the first substrate includes: the circuit pattern board comprises a plurality of first core boards which are arranged in a stacked mode and bonded through first bonding layers, wherein at least part of the first core boards are provided with first circuit pattern layers;

the second substrate includes: the second core boards are arranged in a stacked mode and bonded through second bonding layers, wherein at least part of the second core boards are provided with second circuit pattern layers;

wherein the first substrate and the second substrate are bonded by a third bonding layer.

5. The wiring board of claim 4,

the surface of the first substrate far away from the second substrate is provided with a second metal layer covering the first circuit pattern layer, and the surface of the second substrate far away from the first substrate is provided with a second metal layer covering the second circuit pattern layer;

the side wall of the through hole is provided with a third metal layer connected with the second metal layer on the second circuit pattern layer on the surface of the second substrate far away from the first substrate.

6. A method for manufacturing a circuit board is characterized by comprising the following steps:

providing a first substrate and a second substrate, wherein one surface of the first substrate is provided with a first metal layer;

thickening the first metal layer to 50-500 μm;

laminating the first base material and the second base material, and enabling the first metal layer to be close to the second base material;

arranging a through hole penetrating through the first base material and the second base material;

filling a metal material in the through hole;

performing depth control drilling on a position, corresponding to the through hole, of one surface of the first base material, far away from the second base material, so as to remove part of metal materials in the through hole and form a first blind hole connected with the through hole;

laser drilling is carried out at the position of the first blind hole to form a groove body, wherein the bottom of the groove body penetrates through a part of the first metal layer and is connected with the through hole;

and the projection of the connection position of the groove body and the through hole in the horizontal direction is positioned in the middle of the first metal layer.

7. The manufacturing method according to claim 6, wherein a horizontal projection of a connection position of the groove body and the through hole is lower than a surface of the first metal layer away from the second base material by 0.01 mm to 0.45 mm.

8. The method of manufacturing according to claim 6,

after the first metal layer is thickened to 50-500 μm, the method further comprises the following steps:

manufacturing a first circuit pattern layer on the first metal layer;

before filling the metal material in the through hole, the method further comprises:

and arranging a third metal layer on the side wall of the through hole.

9. The method of manufacturing according to claim 7,

the laser drilling at the position of the first blind hole to form a groove body further comprises:

arranging a fourth metal layer at the bottom of the first blind hole to cover the metal material;

arranging a protective layer on the fourth metal layer;

arranging a first circuit pattern layer on the surface of the first base material far away from the second base material;

arranging a second circuit pattern layer on the surface of the second base material far away from the first base material;

arranging a second metal layer on the first circuit pattern layer of the surface of the first substrate far away from the second substrate and the second circuit pattern layer of the surface of the second substrate far away from the first substrate, wherein the second metal layer on the second circuit pattern layer of the surface of the second substrate far away from the first substrate is electrically connected with the third metal layer;

and removing the protective layer and the fourth metal layer.

10. The method of manufacturing according to claim 9,

the thickness of the fourth metal layer is 2-40 μm, and the thickness of the protective layer is 1-20 μm;

the first metal layer, the second metal layer, the third metal layer and the fourth metal layer are copper layers, the metal material is copper paste, and the protective layer is a tin layer.

Technical Field

The present application relates to the field of circuit board technology, and in particular, to a circuit board and a method for manufacturing the same.

Background

With the development of scientific technology, electronic products have become indispensable daily necessities in life, and PCBs (Printed Circuit boards) are important components of electronic products, so that in recent years, people have more and more demands on functions of electronic products, and thus higher demands are made on PCBs. Generally, in order to facilitate the installation of a device with a special function or a device needing to sink on a PCB, a stepped groove is often required to be arranged on the PCB, a hole is required to be arranged below the stepped groove in order to electrically connect the device with a circuit board, and copper paste is used in the hole for plugging the hole. The repairing method mainly comprises the steps of drilling holes through a laser drilling process, manually repairing the pillars exposed out of copper slurry at the step positions, burning the resin base material by laser drilling, and burning holes in the step positions, so that the pillars can be arranged at the step positions after laser drilling and can only be manually cleaned, and the copper sheet at the bottom of the step can be damaged by manual cleaning, and the quality cannot be guaranteed. The mechanical depth control method mainly comprises the step of drilling through a mechanical drilling process, but because a milling cutter is arc-shaped, the appearance of the step needs to be quadrilateral, the arc-shaped chip at the corner cannot be placed, the depth control chip cannot be placed by adopting the milling cutter, and copper at the bottom of the step can be penetrated in a depth control mode, so that the quality risk is higher.

Therefore, it is necessary to provide a safe and reliable process to solve the above technical problems.

Disclosure of Invention

The application mainly provides a circuit board and a manufacturing method thereof, so that the reliability of a product is improved, and the cost is reduced.

In order to solve the above main technical problem, a first technical solution adopted by the present application is to provide a circuit board, including:

the first base material and the second base material are arranged in a stacked mode, wherein a first metal layer close to the second base material is arranged on the first base material;

the groove body is positioned on the first base material and penetrates through part of the first metal layer, and the through hole penetrates through the second base material and the first metal layer and is connected with the bottom of the groove body;

a metal material located within the via;

wherein the thickness of the first metal layer is 50-500 μm.

In order to solve the above main technical problem, a second technical solution adopted by the present application is to provide a method for manufacturing a circuit board, the method including:

providing a first substrate and a second substrate, wherein one surface of the first substrate is provided with a first metal layer;

thickening the first metal layer to 50-500 μm;

laminating the first base material and the second base material, and enabling the first metal layer to be close to the second base material;

arranging a through hole penetrating through the first base material and the second base material;

filling a metal material in the through hole;

performing depth control drilling on a position, corresponding to the through hole, of one surface of the first base material, far away from the second base material, so as to remove part of metal materials in the through hole and form a first blind hole connected with the through hole;

laser drilling is carried out at the position of the first blind hole to form a groove body, wherein the bottom of the groove body penetrates through a part of the first metal layer and is connected with the through hole;

and the projection of the connection position of the groove body and the through hole in the horizontal direction is positioned in the middle of the first metal layer.

And arranging a groove body with the bottom not penetrating through the first metal layer and connected with the through hole at the position, corresponding to the through hole, of the surface of the first base material far away from the second base material.

The beneficial effect of this application is: be different from prior art's condition, the circuit board of this application is through the thickness thickening that will set up the metal level of step bottom to the copper accuse that can not wear the step bottom when making the step using mechanical accuse deep method drilling, with this reliability that improves the product, reduce cost.

Drawings

FIG. 1 is a schematic structural diagram of an embodiment of a circuit board of the present invention;

FIG. 2 is a schematic flow chart of a first embodiment of a method for manufacturing a circuit board according to the present invention;

fig. 3 is a schematic flow chart of a manufacturing method of a circuit board according to a second embodiment of the invention.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art without any creative effort based on the embodiments in the present application belong to the protection scope of the present application.

Fig. 1 is a schematic structural diagram of an embodiment of the circuit board of the present invention. In this embodiment, the circuit board includes a first substrate 1 and a second substrate 2, the first substrate 1 and the second substrate 2 are bonded by a third bonding layer 3, the surface of the first substrate 1 close to the second substrate 2 has a first metal layer 12, the thickness of the first metal layer 12 is 50 μm to 500 μm, the first substrate 1 has a slot 11 that does not penetrate through the first metal layer 12, the slot 11 is used for placing a device, the second substrate 2 has a through hole 21 that penetrates through the second substrate 2 and is connected to the bottom of the slot 11, the through hole 21 has a metal material 22, and the through hole 21 is used for electrically connecting the device with the first substrate 1 and/or the second substrate 2, in an embodiment, the diameter of the slot 11 is larger than the diameter of the through hole 21.

Wherein the first base material 1 includes a plurality of first core plates 15, as shown in fig. 1, the first base material 1 exemplarily includes only one first core plate 15, in other embodiments, the first base material 1 includes a plurality of first core plates 15, and the plurality of first core plates 15 are bonded by a first bonding layer (not shown). The second substrate 2 includes a plurality of second core boards 26, as shown in fig. 1, the second substrate 2 has a plurality of second core boards 26, in other embodiments, the second substrate 2 may have a layer of second core board 26, and two adjacent second core boards 26 are bonded by a second bonding layer 27.

Wherein the surface of the first core board 15 in the first base material 1 has the first line pattern layer 13, and the surface of the second core board 26 in the second base material 2 has the second line pattern layer 23.

The first core board 15 and the second core board 26 are both copper clad boards, the copper clad boards are basic materials for manufacturing circuit boards, the copper clad boards comprise base material boards and copper foils covered on the base materials, the base material boards are made by soaking materials such as paper substrates, glass fiber cloth substrates, synthetic fiber cloth substrates, non-woven fabric substrates and composite substrates with resin to prepare bonding sheets, the bonding sheets are combined to prepare the copper clad boards, the single side or double sides of the prepared base material boards are covered with the copper foils, and then the copper clad boards are manufactured by hot pressing and curing. The first circuit pattern layer 13 and the second circuit pattern layer 23 are provided on a copper foil.

The first bonding layer, the second bonding layer 27 and the third bonding layer 3 are prepregs which are used as interlayer bonding layers during lamination, specifically, the prepregs mainly comprise resin and reinforcing materials, when a multilayer circuit board is manufactured, glass fiber cloth is usually used as the reinforcing materials, the reinforcing materials are soaked in resin glue solution, then the resin glue solution is subjected to heat treatment and pre-baking to manufacture sheets, the sheets can be softened under heating and pressurization, can be solidified after cooling, have viscosity, and can bond two adjacent layers in a high-temperature laminating process.

In the present application, the tank 11 penetrates through a part of the first metal layer 12, and the through hole 21 penetrates through the first metal layer 12 and communicates with the bottom of the tank 11. Specifically, the projection of the connection point of the tank body 11 and the through hole 21 in the horizontal direction is located in the middle of the first metal layer 12. Thereby the metal layer at the bottom of the tank 11 can be kept intact. Specifically, in an embodiment, the horizontal projection of the connection position of the groove body 11 and the through hole 21 is lower than the surface of the first metal layer 12 away from the second substrate 2 by 0.01 mm to 0.45 mm.

In one embodiment, the circuit board further comprises a second metal layer 14 covering the first circuit pattern layer 13 on the surface of the first substrate 1 away from the second substrate 2, and a second metal layer 24 covering the second circuit pattern layer 23 on the surface of the second substrate 2 away from the first substrate 1; the side wall of the through-hole 21 has a third metal layer 25 connected to a second metal layer 24 on a second line pattern layer 23 on the surface of the second substrate 2 remote from the first substrate 1.

The second metal layer 14 and the second metal layer 24 are plating layers, which can protect the first circuit pattern layer 13 and the second circuit pattern layer 23. The third metal layer 25 on the sidewall of the through hole 21 can make the through hole 21 conductive, and specifically, electroplating is performed on the sidewall of the through hole 21 to form the third metal layer 25, and then the through hole 21 is filled with the metal material 22.

In one embodiment, the first metal layer 12, the second metal layers 14, 24 and the third metal layer 25 are copper, and the metal material 22 is copper paste.

Fig. 2 is a schematic flow chart of a first embodiment of a method for manufacturing a circuit board according to the present application. The method specifically comprises the following steps:

step S101: providing a first substrate and a second substrate, wherein one surface of the first substrate is provided with a first metal layer.

Specifically, the first base material is composed of a plurality of first core boards which are arranged in a stacked manner and bonded through first bonding layers, and the second base material is composed of a plurality of second core boards which are arranged in a stacked manner and bonded through second bonding layers. At least one surface of the first core board is provided with a first circuit pattern layer, and at least one surface of the second core board is provided with a second circuit pattern layer.

The first core board and the second core board are both copper clad boards, the copper clad boards are basic materials for manufacturing the circuit board and comprise base material boards and copper foils covered on the base material boards, the base material boards are made by soaking materials such as paper base boards, glass fiber cloth base boards, synthetic fiber cloth base boards, non-woven fabric base boards, composite base boards and the like with resin to prepare bonding sheets, the bonding sheets are combined to prepare the copper clad boards, the copper foils are covered on one side or two sides of the prepared base material boards, and then the copper clad boards are manufactured by hot-pressing solidification.

The first bonding layer and the second bonding layer are prepregs which are used as interlayer bonding layers during lamination, specifically, the prepregs mainly comprise resin and reinforcing materials, when a multilayer circuit board is manufactured, glass fiber cloth is usually used as the reinforcing materials, the reinforcing materials are soaked in resin glue solution, then the resin glue solution is subjected to heat treatment and pre-baking to prepare sheets, the sheets can be softened under heating and pressurization, can be solidified after cooling, have viscosity, and can bond two adjacent core plates in a high-temperature pressing process.

Step S102: and thickening the first metal layer to 50-500 μm.

Specifically, one surface of the first base material is pasted with a film, the other surface is electroplated, and the metal layer (namely, the first metal layer) on the other surface is thickened, specifically, the first metal layer is thickened to 50-500 μm.

Step S103: and laminating the first base material and the second base material, and enabling the first metal layer to be close to the second base material.

Laminating the first base material and the second base material, wherein the first base material and the second base material are bonded through a third bonding layer, and the thickened first metal layer is arranged close to the second base material.

In one embodiment, the first and second substrates may be browned by a browned black line before the first and second substrates are laminated to increase the surface area of the contact surfaces of the first and second substrates and the bonding layer, so that the first and second substrates are firmly bonded.

Step S104: and arranging a through hole penetrating through the first base material and the second base material.

And arranging at least one through hole penetrating through the first base material and the second base material on the laminated first base material and the laminated second base material.

Step S105: and filling a metal material in the through hole.

And filling a metal material in the through hole, specifically, filling copper paste in the pupil by adopting a copper paste hole filling process.

After the through hole is manufactured, a groove body is arranged at a position, corresponding to the through hole, of a surface, far away from the second base material, of the first base material, and it should be noted that the groove body does not penetrate through the first base material, specifically, the bottom of the groove body needs to be located in the middle of the thickness of the first metal layer, and further, the bottom of the groove body is lower than the surface, far away from the second base material, of the first metal layer by 0.01 mm to 0.45 mm.

In a specific application, the groove is used for placing a device, and the through hole is used for electrically connecting the device with the circuit pattern layer in the first base material and/or the second base material, so that in one embodiment, the diameter of the groove is larger than that of the through hole.

Specifically, in order to ensure the integrity of the bottom of the tank body, the preparation of the tank body is carried out in the following way:

step S106: and performing depth control drilling at a position, corresponding to the through hole, of one surface of the first base material, far away from the second base material to remove part of the metal material in the through hole and form a first blind hole connected with the through hole.

And removing the copper paste at the position where the step needs to be arranged at the position of the first base material corresponding to the through hole by using a depth control drilling mode, specifically, performing depth control drilling at the position of the first base material corresponding to the through hole to form a first blind hole connected with the through hole, wherein the depth control precision is +/-0.05 mm.

Step S107: and laser drilling is carried out at the position of the first blind hole to form a groove body with the bottom penetrating through part of the first metal layer and connected with the through hole.

And laser drilling is carried out at the position where the first blind hole is formed so as to form a groove body for placing the device.

The projection of the connection position of the groove body and the through hole in the horizontal direction is positioned in the middle of the first metal layer, and the projection of the connection position of the groove body and the through hole in the horizontal direction is 0.01 mm-0.45 mm lower than the surface, far away from the second base material, of the first metal layer.

In this embodiment, the copper paste at the step position is removed by using a depth control drill, the depth control precision is ± 0.05 mm, and the step position is processed by using a laser drilling manner, so that the quality can be ensured, and the problem of the arc shape at the bottom of the step can be solved.

Fig. 3 is a schematic flow chart of a manufacturing method of a circuit board according to a second embodiment of the invention. Compared to the first embodiment shown in fig. 2, the difference is that: after step S102, the method further includes:

step S301: and manufacturing a first circuit pattern layer on the first metal layer.

After thickening the first metal layer on one surface of the first substrate, a first circuit pattern layer is manufactured on the surface of the first metal layer. Specifically, before the first substrate and the second substrate are laminated, the surface of the second substrate opposite to the first substrate may also be provided with a second circuit pattern layer as required.

Before step S105, the method further includes:

step S302: and arranging a third metal layer on the side wall of the through hole.

Specifically, after the through hole is formed, electroplating is carried out on the side wall of the through hole in an electroplating mode, so that the through hole forms a metalized through hole.

Step S107 is preceded by:

step S303: arranging a fourth metal layer at the bottom of the first blind hole to cover the metal material;

after the copper paste at the position, where the step needs to be arranged, of the first base material is removed by using a mechanical drilling method, a first circuit pattern layer needs to be formed on the surface, away from the second base material, of the first base material, and in order to prevent damage to the metal material in the through holes at the bottoms of the first blind holes when the first circuit pattern layer is formed, electroplating needs to be performed above the metal material to form a fourth metal layer, wherein in an embodiment, the thickness of the fourth metal layer is 2 μm to 40 μm, and further, the thickness of the fourth metal layer is 15 μm.

Step S304: and arranging a protective layer on the fourth metal layer.

Specifically, a protective layer is formed on the fourth metal layer, and in one embodiment, the protective layer has a thickness of 1 μm to 20 μm, and further, the protective layer has a thickness of 5 μm, and the protective layer is tin.

Step S305: and arranging a first circuit pattern layer on the surface of the first base material far away from the second base material.

And after the metal material in the through hole at the bottom of the first blind hole is protected, forming a first circuit pattern layer on the surface of the first base material far away from the second base material by using alkaline etching liquid medicine.

Step S306: and arranging a second circuit pattern layer on the surface of the second base material far away from the first base material.

Similarly, a second circuit pattern layer is provided on the surface of the second substrate remote from the first substrate using an alkaline etching solution.

In this embodiment, since the protective layer is tin, the metal material in the via hole can be protected during the alkaline etching.

Step S307: and a second metal layer is arranged on the first circuit pattern layer on the surface of the first substrate far away from the second substrate and the second circuit pattern layer on the surface of the second substrate far away from the first substrate, and the second metal layer on the second circuit pattern layer on the surface of the second substrate far away from the first substrate is electrically connected with the third metal layer.

Specifically, electroplating is carried out on a first circuit pattern layer on the surface of the first base material far away from the second base material and a second circuit pattern layer on the surface of the second base material far away from the first base material so as to form a second metal layer covering the first circuit pattern layer and the second circuit pattern layer.

Step S308: and removing the protective layer and the fourth metal layer.

The protective layer (tin) may be removed using an acidic etchant and the fourth metal layer may be etched away.

In the present application, the first metal layer, the second metal layer, the third metal layer and the fourth metal layer are copper layers, and the metal material is copper paste.

In this embodiment, only a part of the related structures of the circuit board are described, and other structures are the same as those of the circuit board in the prior art, and are not described herein again.

According to the circuit board and the manufacturing method thereof, the risk that the metal layer at the bottom of the step is easy to penetrate during mechanical depth control is solved by increasing the thickness of the metal layer at the bottom of the step, and the problem that devices cannot be placed due to the fact that the bottom of the step is in a circular arc shape due to the shape of a milling cutter during mechanical depth control is solved by processing the groove body through a laser drilling process after mechanical drilling. The process improves the quality of the circuit board and reduces the cost.

The above description is only for the purpose of illustrating embodiments of the present invention and is not intended to limit the scope of the present invention, which is defined by the claims and their equivalents, or by direct or indirect application to other related arts.