CN1360462A - Manufacturing method of printed circuit board - Google Patents

Abstract

A method for manufacturing printed circuit board includes such steps as providing a mould with preset circuit pattern, moulding to form a substrate with circuit notch on its surface, and electroplating to form conductor on the circuit notch.

Description

Manufacturing method of printed circuit board

The invention relates to a method for manufacturing a printed circuit board (PC board), in particular to a method that can be applied to rapid production of PC boards and circuits.

The traditional PC board manufacturing method is to provide a substrate first, paste a copper foil on one or both sides of the substrate to form a copper foil substrate, and then make through holes on each side of the copper foil substrate, and use electroplating on the walls of the through holes. Then use the etching method to cooperate with the photoresist and the exposure process to form a circuit on the above-mentioned copper foil substrate, and then complete the production of the single-layer PC board through subsequent processing; or after forming the circuit on the copper foil substrate, Through a gluing process, several copper foil substrates are laminated, and then processed to complete the production of multi-layer PC boards.

According to the above-mentioned production process, starting from the supply of the substrate, a single-layer or multi-layer PC board can be produced through manufacturing steps such as pasting, through-holes, electroplating, and etching. The manufacturing steps are relatively complicated; with the development of technology, PC board products are produced in Miniaturization and modularization are mainly used, but some small modularized PC boards are complicated in the traditional production process and take a lot of time, so they cannot be produced quickly, which is not conducive to the improvement of production efficiency.

The technique of using injection molding to mass-produce products is well known. It makes corresponding molds according to the appearance of the products, then injects the product raw materials into the mold cavity, and injects the products with injection molding equipment, because of its high production efficiency and production efficiency. The method is simple and is widely used in production lines.

Due to the disadvantages of using the traditional copper foil substrate manufacturing process to make PC boards, and the advantages of the injection molding method, the main purpose of the present invention is to introduce the injection molding method into the PC board manufacturing, so as to provide a method different from the traditional copper foil. The PC board manufacturing method of the foil manufacturing process transfers the design of the circuit pattern to the mold, and directly injects a substrate with a circuit formed on the surface by injection molding (such as forming a wiring dent on the surface of the substrate) to reduce manufacturing steps. Thus increasing the production speed.

In order to achieve the above object, the present invention discloses a method for manufacturing a PC board. The manufacturing steps are somewhat different according to the manufactured single-layer PC board or multi-layer PC board. If a single-layer PC board is to be formed, the manufacturing steps include at least : providing a mold with a predetermined circuit pattern; injecting plastic into the mold to form a substrate with circuit dents on the surface; forming a conductive film on the surface of the circuit dent; and forming a conductor on the surface of the conductive film layer to form conductive traces on the substrate.

According to the technology of the present invention, after the conductive circuit on the substrate is formed, subsequent processing (such as solder mask treatment) is performed, thereby completing the production of a single-layer PC board.

If a multi-layer PC board is to be formed, its manufacturing steps at least include: providing a mold with a predetermined circuit pattern; injecting the plastic into the mold to form a substrate with circuit dents on at least two surfaces; A conductive film; a conductive layer is formed on the surface of the conductive film for forming conductive lines on at least two substrates; a through hole is formed on at least two substrates, and plating is performed in the through hole for Connecting the conductive lines of at least two substrates; making the at least two substrates glued to form a multi-layer PC board. After the multilayer PC board is formed, subsequent processing (such as solder mask treatment) is performed to complete the production of the multilayer PC board.

In order to make the above and other purposes, features, and advantages of the present invention clearer and easier to understand, a preferred embodiment will be described in detail below with reference to the accompanying drawings.

Fig. 1 is the manufacturing flowchart of manufacturing PC board of the present invention;

2 is a schematic diagram of a substrate obtained by injection molding, wherein a circuit pattern is formed on the surface of the substrate;

Fig. 3 is a structural sectional view of a multilayer PC board.

According to the PC board manufacturing method disclosed in the present invention, the injection molding method is introduced into the PC board manufacturing process, and the design of the circuit pattern is transferred to the mould, and the plastic can be directly molded into a surface with circuit dents through the mould. Substrates, so that the formation of substrates and circuit dents can be completed synchronously, so the manufacturing steps can be reduced. Due to the high production speed of the injection molding method, it can solve the problem that the production process of copper foil substrates in the known technology is complicated and cannot be quickly produced PC boards; Therefore, the manufacturing process disclosed in the present invention can be applied to the production of dynamic random access memory modules (DRAMDODULE) and other miniaturized and modularized electronic products with a large output and simple circuit patterns on the PC board.

Wherein about the manufacturing steps of above-mentioned PC board, referring to the flowchart shown in Figure 1, it comprises:

1 Injection molding substrates containing circuit dents;

2 conducting conductive treatment to the line dents to form a conductive film;

3 performing electroplating on the surface of the circuit dent with the conductive film to form a conductor layer;

4 gluing the substrates to create a multi-layer PC board; and

5 for solder mask treatment.

The details of each step are as follows:

First, provide a mold with a predetermined circuit pattern; the mold used can be a two-plate mold, which is mainly composed of a fixed side template and a movable side template. The movable side template is usually in a convex shape, so it is also called positive template, which molds the inner surface of the molded product, and the fixed side template is usually in a concave shape, so it is also called a negative template, which molds the outer surface of the molded product, and in the present invention, the design of the circuit pattern is directly transferred to On the mold, it is formed by using an etching method (such as dry etching or wet etching) and matching a mask (Mask) to form a circuit pattern on the mold.

Then, the plastic is injected into the mold cavity, and after molding, the molded product of the substrate 10 is injected with the injection equipment, and the surface of the obtained molded product of the substrate 10 is formed with a dent of the circuit 11 (as shown in FIG. 2 ), the dent Corresponding to the bumps of the positive template, in this step, the circuit 11 is formed with dents. When the subsequent electroplating conductor layer forms dents in the circuit 11, there will be no problem of diffusion, and the thickness of the conductor layer can be made uniform. However, in this step, the circuit 11 on the substrate 10 does not yet have a conductive function. Wherein the thickness of the substrate 10 is very small, special attention should be paid to the type of plastic used to avoid the substrate 10 being too hard or too soft. In the present invention, the choice of plastic is preferably a material containing fibers.

After obtaining the above-mentioned substrate 10, the dents of the circuit 11 on the substrate 10 cannot conduct electricity, and a conductive layer needs to be plated on the dents of the above-mentioned circuit 11 to conduct electricity. It is not feasible to electroplate the conductor, and a conductive film must be formed on the surface of the dent of the circuit 11, and then the conductor is electroplated on the conductive film. Therefore, in this step, a conductive film is formed on the surface of the dent in the circuit 11, which is carried out by a conductive treatment method, wherein the conductive treatment method includes two methods, namely a photolithography method and a micro-etching treatment method, Among them, the photolithographic method can be divided into positive and negative according to the photosensitive material used. The positive film method is to use a positive photosensitive material, and then cooperate with the setting of the mask to process the part of the circuit on the substrate; while the negative film method is to use a negative photosensitive material, cooperate with the setting of the mask to process the non-circuit part of the substrate, micro-etching processing method The conductive film is directly formed on the line dent by using an etching method. No matter which method is used, the surface of the formed conductive film is uneven, thereby increasing the adhesion of the conductive layer formed in the subsequent electroplating step. After the conductive treatment is completed, a conductive layer made of a conductor is formed on the surface of the above-mentioned conductive film by electroplating (or other methods) to form a conductive circuit on the substrate; users can choose an appropriate conductor according to their needs The type and the thickness of the conductor layer, up to this step, the production of the single-layer circuit is completed.

When the user needs to form a multi-layer circuit, it can be completed by means of lamination; wherein the above-mentioned method of lamination is to form the substrates 10a, 10b ( As shown in Figure 3), a through hole 12 is formed on these substrates 10a, 10b, and plating is carried out in the through hole 12, so as to connect the conductive circuits 11a, 11b of several substrates 10a, 10b, and then through a gluing process to form a multi-layer PC board, wherein the above-mentioned gluing process is a known technology, and its content will not be described in detail here. It mainly uses glue dispensing to coat adhesives at the joints of the substrates, and then cooperates with the heating and pressing process to make the substrates Overlap and combine to form a multi-layer PC board.

After forming a single-layer circuit or a multi-layer circuit, subsequent processing can be performed to complete the manufacture of a single-layer PC board or a multi-layer PC board. The above-mentioned processing includes solder mask treatment, which is formed on the surface of the substrate. 1. Solder mask.

Known from the above description, the present invention is an improvement of the manufacturing process for increasing the production speed of PC boards. The existing manufacturing method is to use the copper foil substrate manufacturing process. The production efficiency of the board is not high, but the present invention directly manufactures a substrate with circuit dents formed on the surface by the injection molding method with the transfer of the circuit design, which can reduce the manufacturing steps and achieve the purpose of rapid production of the PC board.

Although the present invention has been described with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make many changes and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection shall prevail as defined by the appended claims.

Claims (12)

1. the manufacture method of a PC plate, in order to form the circuit of individual layer, it comprises the following step at least:

One mould with predetermined circuit patterns is provided;

It is the substrate that a surface is formed with the circuit indenture that plastics are injected mould molding;

Form a conducting film on the surface of described circuit indenture; And

Form a conductor layer on the surface of described conducting film, constitute the conducting wire on the described substrate.

2. the manufacture method of PC plate as claimed in claim 1 wherein after forming described conductor layer step, also comprises the described substrate of a processing to form the step of an individual layer PC plate.

3. the manufacture method of PC plate as claimed in claim 1, wherein said plastics are the materials that contain fiber.

4. the manufacture method of PC plate as claimed in claim 1, the circuit pattern of wherein said mould utilize engraving method to form.

5. the manufacture method of PC plate as claimed in claim 1, wherein forming described conducting film step can be finished by one of modes such as positive, negative film or microetch.

6. the manufacture method of PC plate as claimed in claim 1, the step that wherein forms described conductor layer is finished by an electro-plating method.

7. the manufacture method of a PC plate, in order to form the circuit of multilayer, it comprises the following step at least:

One mould with predetermined circuit patterns is provided;

Plastics are injected mould molding is formed with the circuit indenture at least two surfaces substrate;

Form a conducting film on the surface of described circuit indenture;

Form a conductor layer on the surface of described conducting film, be used to constitute the conducting wire on described at least two substrates;

On described two substrates, form a through hole at least, and in described through hole, carry out plating, in order to be communicated with the conducting wire on described at least two substrates;

Make described at least two base plate bondings, to form a multilayer PC plate.

8. the manufacture method of PC plate as claimed in claim 7 wherein after forming multilayer line, also comprises the step of the described multilayer PC plate of a processing with the manufacturing of finishing multilayer PC plate.

9. the manufacture method of PC plate as claimed in claim 7, wherein said plastics are the materials that contain fiber.

10. the manufacture method of PC plate as claimed in claim 7, the circuit pattern of wherein said mould are to utilize engraving method to form.

11. the manufacture method of PC plate as claimed in claim 7, wherein forming described conducting film step can be finished by among the modes such as positive, negative film or microetch any.

12. the manufacture method of PC plate as claimed in claim 7, the step that wherein forms described conductor layer is finished by an electro-plating method.

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