阅读说明：本技术 Pcb制作方法和pcb (PCB manufacturing method and PCB ) 是由 郭耀强 彭文才 陈黎阳 于 2019-11-15 设计创作，主要内容包括：本发明提供了一种PCB制作方法和一种PCB,将PCB上的电极除了与底板的连接面以外的全部表面利用耐腐蚀金属覆盖,并形成覆盖层。与现有带电极的PCB当中电极侧壁或其他表面被阻焊油墨覆盖的结构相比,本发明所提供的PCB在严苛的化学腐蚀环境下,耐腐蚀金属所形成的的覆盖层具有良好的完整性和封闭性,保证电极工作的可靠性,可应用于化工、环保、医疗卫生等领域的电化学检测过程。(The invention provides a PCB manufacturing method and a PCB, wherein all surfaces of electrodes on the PCB except the connecting surface with a bottom plate are covered by corrosion-resistant metal, and a covering layer is formed. Compared with the structure that the side wall or other surfaces of the electrode in the existing PCB with the electrode are covered by the solder resist ink, the PCB provided by the invention has good integrity and closure of a covering layer formed by corrosion-resistant metal under a severe chemical corrosion environment, ensures the working reliability of the electrode, and can be applied to the electrochemical detection process in the fields of chemical industry, environmental protection, medical health and the like.)

1. A method for manufacturing a PCB, wherein the PCB is a double-layer board or a multi-layer board and is provided with a top layer and a bottom layer which are positioned at the outermost sides, comprises the following steps:

s10, manufacturing a top layer circuit and a top layer electrode on the top layer, wherein the top layer electrode is not conducted with the top layer circuit, and the top layer electrode is conducted with the bottom layer through an internal conducting hole;

s30, printing solder resist or a dry film covering on the top layer, so that the top layer circuits are covered by the solder resist or the dry film;

and S50, electroplating the corrosion-resistant metal on the top electrode, so that the corrosion-resistant metal completely covers the surface of the top electrode except the surface connected with the bottom plate.

2. The method for manufacturing a PCB of claim 1, wherein the step S50 is preceded by the steps of:

s40, printing solder resist or a dry film covering on the bottom layer to enable the copper surface of the bottom layer to be covered by the solder resist or the dry film;

step S50 is followed by the following steps:

and S60, removing the bottom solder mask or the dry film, and manufacturing a bottom circuit.

3. The method for manufacturing a PCB of claim 2, wherein the step S60 further comprises the steps of:

and S62, manufacturing a bottom electrode, wherein the top electrode and the bottom electrode are communicated through an inner through hole.

4. The method for manufacturing a PCB according to claim 3, wherein after the step S62, the method further comprises the following steps:

s70, printing solder resist or a dry film on the top layer to make the top layer circuit and the top layer electrode covered by the solder resist or the dry film;

s72, printing solder resist or a dry film on the bottom layer, so that the rest circuits in the bottom layer except the bottom layer electrodes are covered by the solder resist or the dry film;

and S74, electroplating the corrosion-resistant metal on the bottom electrode, so that the corrosion-resistant metal completely covers the bottom electrode.

5. The method of claim 4, wherein the corrosion resistant metal on the bottom electrode and the top electrode are different materials.

6. The method for manufacturing a PCB of claim 1, wherein the step S10 further comprises the steps of:

s12, manufacturing a bottom layer circuit and a bottom layer electrode, wherein the bottom layer circuit is not communicated with the bottom layer electrode, and the top layer electrode is communicated with the bottom layer electrode through an internal through hole;

step S30 further includes the steps of:

s32, printing solder resist or a dry film on the bottom layer to enable the bottom layer circuit to be covered by the solder resist or the dry film;

step S50 further includes the steps of:

and S52, electroplating the corrosion-resistant metal on the bottom electrode, so that the corrosion-resistant metal completely covers the surface of the bottom electrode except the surface connected with the bottom plate.

7. The method for manufacturing a PCB of any of claims 1-6, wherein the corrosion resistant metal is one or a combination of any of gold, silver, nickel, platinum and palladium gold.

8. A PCB manufacturing method according to any of claims 1-6, wherein the solder mask is a corrosion resistant ink.

9. A method of fabricating a PCB according to any of claims 1 to 6 wherein the thickness of the corrosion resistant metal is greater than 1 μm.

10. A PCB, comprising: the bottom surface of the electrode is fixedly connected to the bottom plate, and the covering layer covers the rest surfaces of the substrate.

11. The PCB of claim 10, wherein the material of the cover layer comprises any one or a combination of any several of gold, silver, nickel, platinum and palladium.

12. The PCB of claim 10, wherein the PCB is a double-layer board or a multi-layer board, the number of the electrodes is one or more, and the electrodes are located on the outer layer of the PCB.

13. The PCB of any of claims 10-12, wherein the cover layer is thicker than 1 μ ι η.

Technical Field

The invention relates to the technical field of PCB manufacturing, in particular to a PCB manufacturing method and a PCB.

Background

In recent years, electrochemical biosensors have become an important research direction in biochemical analysis and clinical examination due to their advantages such as high sensitivity, good stability, and simple operation. The electrode is used as a conversion element and a fixed carrier, biological sensitive substances such as antigens, antibodies, enzymes, hormones and the like or organisms are fixed on the electrode as the sensitive elements, and a target molecule and a reaction signal thereof are converted into an electric signal such as capacitance, current, potential, conductivity and the like through the specific recognition function between biomolecules, so that the qualitative or quantitative detection of a target analyte is realized. The enzyme is used as a sensitive element, the electrode is used as a conversion element, and an undetectable substrate is converted into a product which can be detected by an electrochemical method through the catalytic action of the enzyme.

With the development of PCB process technology, PCBs are no longer limited to the function of providing interconnection services for components. In the field of clinical medical examination, the PCB can be designed as a part of an electrochemical biosensor so as to collect electrochemical signals of different components in a blood sample and provide reliable electrochemical measurement service. In the prior art, the electrode covered with inert metal is used for realizing information acquisition, but the top surface of the electrode on the PCB board is covered with the inert metal, and the side surface is covered with conventional solder resist materials such as ink and the like, so that the sealing property and the integrity of the electrode are poor, and a good working state cannot be kept in a severe chemical corrosion environment.

Disclosure of Invention

In view of the above, it is necessary to provide a PCB manufacturing method and a PCB, aiming at the problem of poor integrity and sealing of the current electrodes on the PCB.

The above purpose is realized by the following technical scheme:

a method for manufacturing a PCB which is a double-layer board or a multi-layer board and is provided with a top layer and a bottom layer which are positioned at the outermost sides comprises the following steps:

s10, manufacturing a top layer circuit and a top layer electrode on the top layer, wherein the top layer electrode is not conducted with the top layer circuit, and the top layer electrode is conducted with the bottom layer through an internal conducting hole;

s30, printing solder resist or a dry film covering on the top layer, so that the top layer circuits are covered by the solder resist or the dry film;

and S50, electroplating the corrosion-resistant metal on the top electrode, so that the corrosion-resistant metal completely covers the surface of the top electrode except the surface connected with the bottom plate.

In one embodiment, step S50 is preceded by the following steps:

s40, printing solder resist or a dry film covering on the bottom layer to enable the copper surface of the bottom layer to be covered by the solder resist or the dry film;

step S50 is followed by the following steps:

and S60, removing the bottom solder mask or the dry film, and manufacturing a bottom circuit.

In one embodiment, step S60 further includes the following steps:

and S62, manufacturing a bottom electrode, wherein the top electrode and the bottom electrode are communicated through an inner through hole.

In one embodiment, after step S62, the method further includes the following steps:

s70, printing solder resist or a dry film on the top layer to make the top layer circuit and the top layer electrode covered by the solder resist or the dry film;

s72, printing solder resist or a dry film on the bottom layer, so that the rest circuits in the bottom layer except the bottom layer electrodes are covered by the solder resist or the dry film;

and S74, electroplating the corrosion-resistant metal on the bottom electrode, so that the corrosion-resistant metal completely covers the bottom electrode.

In one embodiment, the corrosion-resistant metal on the bottom electrode and the top electrode are different materials.

In one embodiment, step S10 further includes the following steps:

s12, manufacturing a bottom layer circuit and a bottom layer electrode, wherein the bottom layer circuit is not communicated with the bottom layer electrode, and the top layer electrode is communicated with the bottom layer electrode through an internal through hole;

step S30 further includes the steps of:

s32, printing solder resist or a dry film on the bottom layer to enable the bottom layer circuit to be covered by the solder resist or the dry film;

step S50 further includes the steps of:

and S52, electroplating the corrosion-resistant metal on the bottom electrode, so that the corrosion-resistant metal completely covers the surface of the bottom electrode except the surface connected with the bottom plate.

In one embodiment, the corrosion-resistant metal is one or a combination of any of gold, silver, nickel, platinum and palladium gold.

In one embodiment, the solder resist is a corrosion resistant ink.

In one embodiment, the corrosion-resistant metal has a thickness greater than 1 μm.

The present invention also provides a PCB including: the bottom surface of the electrode is fixedly connected to the bottom plate, and the covering layer covers the rest surfaces of the substrate.

In one embodiment, the material of the cover layer includes any one or a combination of any several of gold, silver, nickel, platinum and palladium gold.

In one embodiment, the PCB is a double-layer board or a multi-layer board, the number of the electrodes is one or more, and the electrodes are located on the outer layer of the PCB.

In one embodiment, the cover layer is greater than 1 μm thick.

The invention has the beneficial effects that:

the invention provides a PCB manufacturing method and a PCB, wherein all surfaces of electrodes on the PCB except the connecting surface with a bottom plate are covered by corrosion-resistant metal, and a covering layer is formed. Compared with the structure that the side wall or other surfaces of the electrode in the existing PCB with the electrode are covered by the solder resist ink, the PCB provided by the invention has good integrity and closure of a covering layer formed by corrosion-resistant metal under a severe chemical corrosion environment, ensures the working reliability of the electrode, and can be applied to the electrochemical detection process in the fields of chemical industry, environmental protection, medical health and the like.

Drawings

FIG. 1 is a schematic diagram of a prior art PCB top electrode covered with multiple layers of corrosion-resistant metal;

FIG. 2 is a schematic view of a fully covered electrode structure with a corrosion-resistant metal according to an embodiment of the present invention;

fig. 3 to 8 are schematic product structures at different stages of a PCB manufacturing method according to an embodiment of the present invention:

FIG. 3 is a schematic diagram of a product structure with a via hole, a top layer circuit and a top layer electrode fabricated;

FIG. 4 is a schematic view of the product structure after the top circuit is covered with solder mask based on FIG. 3;

FIG. 5 is a schematic view of the product structure of FIG. 4 after a dry film is coated on the bottom layer;

FIG. 6 is a schematic structural diagram of the product after the top electrode is covered with a corrosion-resistant metal on the basis of FIG. 5;

FIG. 7 is a schematic structural diagram of a product manufactured with the bottom layer circuit and the bottom layer electrode on the basis of FIG. 6;

FIG. 8 is a schematic view of the product covered with a dry film on the top layer shown in FIG. 7;

FIG. 9 is a schematic structural diagram of a product obtained by covering a solder resist on the bottom-layer circuit and a corrosion-resistant metal on the bottom-layer electrode on the basis of FIG. 8;

fig. 10 is a schematic structural diagram of a multi-layer board manufactured by the PCB manufacturing method according to an embodiment of the present invention.

Wherein:

a PCB (100); a base plate 101; a via hole 102; solder resist 103; a dry film 104; a top layer electrode 111; a bottom electrode 112; a top layer circuit 131; a bottom layer wiring 132; a corrosion-resistant metal 120; a nickel layer 121; a gold layer 122; a platinum layer 123.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below by way of embodiments with reference to the accompanying drawings. 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 numbering of the components themselves, such as "first", "second", etc., is used herein only to distinguish between the objects depicted and not to have any sequential or technical meaning. The term "connected" and "coupled" when used in this application, unless otherwise indicated, includes both direct and indirect connections (couplings). In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

The invention provides a PCB manufacturing method, which enables all the surfaces of the electrodes 111 of the outer layer of the PCB except the connecting surfaces with the bottom and the bottom 101 to be completely covered by a covering layer formed by corrosion-resistant metal 120 through adjusting the manufacturing process, as shown in figure 2. In other words, the base plate 101 and the cover layer form a surrounding structure, completely covering the electrode 111. In the prior art, as shown in fig. 1, the top surface of the electrode is generally covered only with corrosion-resistant metal (including nickel layer 121, gold layer 122 and platinum layer 123 in fig. 1), the bottom surface of the electrode 111 is connected with the bottom plate 101, the side surface of the electrode 111 is covered with conventional solder resist, and the electrode 111 covered with conventional solder resist has poor sealing performance and integrity in an environment with strong chemical corrosion, resulting in failure of the electrode 111. According to the invention, the corrosion-resistant metal is used for covering the electrode, so that the electrode manufactured by the PCB manufacturing method provided by the invention has better integrity and closure, and can be applied to signal detection in the fields of chemical industry, environmental protection, medical health and the like.

Specifically, for a multi-layer board and a dual-layer board comprising a top layer and a bottom layer, the PCB manufacturing method comprises the following steps:

s10, as shown in fig. 3, the top layer circuit 131 and the top layer electrode 111 are fabricated on the top layer, the top layer electrode 111 and the top layer circuit 131 are not conducted, and the top layer electrode 111 is conducted to the bottom layer through the inner via hole 102;

s30, as shown in fig. 4, printing solder mask 103 or dry film 104 on the top layer, so that the top layer circuit 131 is covered by the solder mask 103 or dry film 104;

s50, as shown in fig. 6, the corrosion-resistant metal 120 is plated on the top electrode 111 so that the corrosion-resistant metal 120 completely covers the surface of the top electrode 111 except the surface connected to the bottom plate 101.

The steps before step S10 and step S10 are the same as the conventional PCB manufacturing method, and the top layer circuit 131 and the top layer electrode 111 not in conduction with the top layer circuit 131 are manufactured in step S10, and since the top layer electrode 111 needs to be covered with the corrosion-resistant metal 120, the top layer electrode 111 and the rest of the surface where the top layer electrode 111 is located cannot have a contact relationship, and thus, do not have a conduction relationship.

The step S30 covers the top layer circuit 131 with the solder resist 103 or the dry film 104 in order to prevent the corrosion-resistant metal 120 from being plated by mistake at other positions when the electrodes are plated. Also, the solder resist 103 in step S30 should not contact any part of the top layer electrode 111 so as not to affect the sealing and integrity of the top layer electrode 111.

Step S50 is to completely cover the electrode with the corrosion-resistant metal 120 so that the electrode is not in contact with the outside except for the connection surface with the base plate 101. For the sake of understanding the covering of the electrode by the corrosion-resistant metal 120, a cylindrical electrode and a rectangular parallelepiped electrode are exemplified: for a cylindrical electrode, the axis is perpendicular to the floor surface, the bottom surface is connected to the bottom plate 101, and the side and top surfaces are covered with corrosion-resistant metal 120. For a rectangular parallelepiped electrode, one of the sides of the electrode is connected to the base plate 101, and the remaining five sides are covered with a corrosion-resistant metal 120. It will be appreciated that for other regularly or irregularly shaped electrodes, the corrosion-resistant metal 120 can cover all surfaces of the electrode except the surface in contact with the base plate 101.

It should be noted that the above and below references to the top and bottom layers are not intended to distinguish between locations, but rather to facilitate the distinction between the two outer layers of a two-layer or multi-layer board, the two outer layers being named differently. Obviously, the electrode fabrication in steps S10 to S50 may also be performed on the bottom layer.

In one embodiment, before step S50, as shown in fig. 5, step S40 is performed: printing a solder mask 103 or a covering dry film 104 on the bottom layer, so that the copper surface of the bottom layer is covered by the solder mask 103 or the dry film 104; this step is to prevent plating errors on the underlying copper surface when plating the top electrode 111.

After step S50, as shown in fig. 7, step S60 is performed: the solder resist 103 or the dry film 104 on the underlayer is removed, and a wiring is formed on the underlayer. Further, step S62 is performed to fabricate the bottom layer electrode 112 at the same time as the bottom layer wiring 132, and the relationship between the bottom layer electrode 112 and the bottom layer wiring 132 is the same as the relationship between the top layer electrode 111 and the top layer wiring 131. For the PCB without the bottom electrode 112, the top electrode 111 is conducted to the bottom circuit 132 through the inner via hole 102, and transmits the electrical signal in the environment of the top side to the bottom circuit 132, so as to implement signal transmission. For the PCB with the bottom electrode 112, the top electrode 111 is conducted to the bottom electrode 112 through the inner via hole 102, and transmits the electrical signal in the environment of the top side to the bottom electrode 112, and then the bottom electrode 112 transmits the electrical signal to the outside, thereby completing the signal transmission.

Further, after the bottom electrode 112 is manufactured, in order to prevent the bottom electrode 112 from failing in a strong chemical corrosion environment, the bottom electrode 112 is also plated with the corrosion-resistant metal 120, which includes the following steps:

s70, printing solder mask 103 or dry film 104 on the top layer, so that the top layer circuit 131 and the top layer electrode 111 are covered by the solder mask 103 or dry film 104;

s72, printing solder mask 103 or dry film 104 on the bottom layer, so that the rest circuits in the bottom layer except the bottom layer electrode 112 are covered by the solder mask 103 or the dry film 104;

s74, the corrosion-resistant metal 120 is plated on the bottom electrode 112 such that the corrosion-resistant metal 120 completely covers the bottom electrode 112.

The steps S70 and S72 are to prevent the corrosion-resistant metal 120 from being plated at other positions by mistake when the bottom electrode 112 is plated, and the relationship between the bottom electrode 112 and the corrosion-resistant metal 120 is the same as the relationship between the top electrode 111 and the corrosion-resistant metal 120, which is not described herein again. The PCB passing through the step S70 is shown in fig. 8, and the PCB passing through the steps S72 and S74 is shown in fig. 9.

And, the steps S10 to S74 are performed by two times of electroplating, and the electrodes of the top layer and the bottom layer of the PCB are plated with the corrosion-resistant metal 120, and the electroplating processes of the two are not interfered with each other, so that the corrosion-resistant metal 120 with different materials can be plated on the top layer electrode 111 and the bottom layer electrode 112 to adapt to different chemical environments.

In the case that the top layer electrode 111 and the bottom layer electrode 112 do not need to be made of corrosion resistant materials with different materials, the electroplating operations of the top layer electrode 111 and the bottom layer electrode 112 are performed synchronously in order to simplify the steps. Specifically, the method comprises the following steps:

s10, manufacturing a top layer circuit 131 and a top layer electrode 111 on the top layer, wherein the top layer electrode 111 is not conducted with the top layer circuit 131, and the top layer electrode 111 is conducted with the bottom layer through the internal conducting hole 102;

s12, manufacturing a bottom layer circuit 132 and a bottom layer electrode 112, wherein the bottom layer circuit 132 is not conducted with the bottom layer electrode 112, and the top layer electrode 111 is communicated with the bottom layer electrode 112 through the inner conducting hole 102;

s30, printing solder masks 103 or covering dry films 104 on the top layer, so that the top layer circuits 131 are covered by the solder masks 103 or the dry films 104;

s32, printing solder masks 103 or covering dry films 104 on the bottom layer, so that the bottom layer lines 132 are covered by the solder masks 103 or the dry films 104;

s50, electroplating the corrosion-resistant metal 120 on the top electrode 111, so that the corrosion-resistant metal 120 completely covers the top electrode 111 except the surface connected with the bottom plate 101;

s52, the corrosion-resistant metal 120 is plated on the bottom layer electrode 112, so that the corrosion-resistant metal 120 completely covers the surface of the bottom layer electrode 112 except the surface connected to the bottom plate 101.

Wherein, the steps S10 and S12 are the fabrication of the top layer electrode 111 and the bottom layer electrode 112, and the two steps can be performed in any order;

in order to prevent the wires other than the electrodes from being plated by mistake, the steps S30 and S32 may be performed in an arbitrary order;

the steps S50 and S52 are the electroplating of the top layer electrode 111 and the bottom layer electrode 112, and the two steps may be performed in any order.

In the above embodiments, the corrosion-resistant metal material is one or a combination of any of gold, silver, nickel, platinum and palladium, and may be other corrosion-resistant materials. The platinum is an inert metal, is corrosion-resistant and has good catalytic performance. When the corrosion-resistant metal is a plurality of materials, the plurality of materials are not mixed, but one material is used as a single covering layer, and finally, the covering layer is in a multi-layer covering form.

In the embodiment, the adopted solder resist is the corrosion-resistant ink, the solidified corrosion-resistant ink is used as the plating resistance layer of the electroplated platinum, the problem of film clamping is avoided, the plating resistance is improved, manual plate edge encapsulation is not needed to be considered when the platinum is electroplated, the process is simplified, and the automatic operation is facilitated.

In the above embodiments, the thickness of the corrosion-resistant metal is greater than 1 μm, and the thickness of the corrosion-resistant metal can be adjusted according to specific requirements.

Compared with the prior art, the PCB manufacturing method and the PCB manufactured by the method at least have the following advantages:

1. the corrosion-resistant metal is used as an electrode material, has good biocompatibility, has no toxicity to biological molecules, cells and tissues, and is a good conductor of electricity.

2. Directly electroplating platinum on copper, leveling the copper surface before plating the corrosion-resistant metal, smoothing the surface, submitting the compactness of platinum crystals, enabling the thickness of the corrosion-resistant metal to be more than or equal to 1.0 mu m, and having high reliability, high deposition rate and strong corrosion resistance;

3. the corrosion-resistant metal is electroplated by adopting a mode of laser drilling micropore conduction and single-side manufacturing electroplating, so that the wiring density of the board surface can be improved, and the utilization rate of the board surface is improved;

4. the solidified corrosion-resistant ink is used as an anti-plating layer for electroplating corrosion-resistant metal, so that the problem of film clamping is avoided, the anti-plating capability is improved, manual plate edge encapsulation is not required to be considered when the corrosion-resistant metal is electroplated, the process is simplified, and the automatic operation is facilitated;

5. the corrosion-resistant metal layer completely wraps the copper layer, and no lead wire is left at the periphery. The electrode is prevented from being corroded by chemical reaction solution, and the reliability of electrochemical signal acquisition is improved.