CN110446372B

CN110446372B - Manufacturing method of improved multi-layer fine circuit board

Info

Publication number: CN110446372B
Application number: CN201910809144.4A
Authority: CN
Inventors: 古满香; 王健; 孙慧娟; 孙彬; 沈洪; 李晓华
Original assignee: Jiangsu Shangda Electronics Co Ltd
Current assignee: Jiangsu Shangda Electronics Co Ltd
Priority date: 2019-08-29
Filing date: 2019-08-29
Publication date: 2021-07-27
Anticipated expiration: 2039-08-29
Also published as: CN110446372A

Abstract

The invention discloses a manufacturing method of an improved multi-layer fine circuit board, and belongs to the technical field of fine circuit board manufacturing. The method comprises the steps of firstly pressing a dry film, exposing, developing, etching and stripping the film to form a circuit, then coating a layer of conductive film on the product except for a plating lead, then drilling, hole conductivity and copper plating to form a via hole, then reacting copper deposited on the conductive film through microetching liquid, and finally stripping all the conductive films on the product through stripping liquid. The invention has the beneficial effects that: drilling is carried out after the conductive film is coated, so that the hole is prevented from being blocked by the conductive film, the performance requirement on the conductive film is reduced, and the cost is saved; the process of exposing and developing the conductive film is omitted, the time of exposing and developing operation and the standing time caused by exposing and developing are omitted, and the production period of the product is shortened; the process flow design is simple, ingenious, reasonable and easy to realize, and the cost of water, electricity, materials and the like, the equipment cost and the labor cost are reduced.

Description

Manufacturing method of improved multi-layer fine circuit board

Technical Field

The invention relates to a manufacturing method of an improved multi-layer fine circuit board, and belongs to the technical field of fine circuit board manufacturing.

Background

With the development of fine circuit boards and high-frequency circuit boards, higher requirements are put on the precision of circuits, and the transmission of signals can be influenced by slight deviation of the circuits. Based on this, the common full-plate electroplating process has not been able to manufacture fine circuits meeting the requirements. Although the pattern electroplating process can be used for manufacturing a fine circuit, due to the limitation of the manufacturing process, the product short circuit caused by the film clamping is easy to generate, and the open circuit phenomenon caused by the permeation of etching liquid due to the poor combination of a dry film and the product caused by the hole step is easy to generate, so that the yield of the product is greatly reduced due to the defects of the two aspects. Although the EP process solves the two defects, the production period is long, the flow is multiple and the cost is high due to the complex process.

Compared with the more traditional pattern electroplating, the existing manufacturing method of the fine circuit board really solves the short circuit problem caused by film clamping in the pattern electroplating and the open circuit problem caused by hole steps, however, compared with the flow of the pattern electroplating, the manufacturing process flow of the fine circuit board has no advantages, is not simplified, and is even longer than the pattern process flow, and the length of the flow is related to the production period and the cost. In the prior art, a copper foil is firstly subjected to dry film pressing, then a product subjected to dry film pressing is subjected to exposure and development, then a circuit and a hole disc are etched, the remaining dry film is removed, then laser drilling is carried out, a conductive film is coated on the product subjected to drilling, exposure and development are carried out, hole conductive treatment is carried out, hole copper is plated, copper on the conductive film is removed by microetching, and finally the remaining conductive film is stripped to obtain the fine circuit. Briefly, the procedure is as follows: dry film pressing → exposure → development → etching → dry film peeling → laser drilling → conductive film coating → exposure → development → hole conductivity → copper plating → micro-etching → conductive film peeling, for 13 steps in total. The conductive film is coated after the product is drilled, so that the conductive film enters the hole, the hole blocked by the conductive film cannot be subjected to subsequent hole conductivity and copper plating treatment, an exposure process and a development process have to be added to remove the conductive film in the hole, and therefore, the production period is prolonged, and the costs of water, electricity, materials and the like, the equipment cost and the labor cost are increased.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a manufacturing method of an improved multilayer fine circuit board.

The invention is realized by the following technical scheme: a method for manufacturing an improved multi-layer fine circuit board is characterized in that a circuit is manufactured on a product through dry film pressing, exposure, development, etching and film stripping, a layer of conductive film is coated on the product except for a plating lead, then drilling, hole conductivity and copper plating are carried out to manufacture a via hole, copper deposited on the conductive film is reacted through micro-etching liquid, and finally all the conductive films on the product are stripped through stripping liquid.

The method comprises the following steps:

step A: laminating a layer of dry film on the outer side of the product copper foil;

and B: carrying out exposure and development;

and C: etching is carried out;

step D: stripping the film;

step E: coating a layer of conductive film on the product;

step F: laser drilling;

step G: after the hole is formed, conducting treatment is carried out, and a conducting substance is attached to the hole wall;

step H: plating hole copper;

step I: microetching to remove copper deposited on the conductive film;

step J: and stripping the residual conductive film.

The product is a multilayer fine circuit board.

The conductive film has viscosity and conductivity, is not attacked and dissolved by liquid medicine when in hole conductivity and hole copper plating, and is easy to peel.

And E, coating the conductive film to avoid electroplating leads.

And F, forming a hole meeting the specification at a specified position under the instantaneous action of the high-energy laser beam.

The invention has the beneficial effects that: the conductive film is coated and then drilled, so that the problem that the hole is blocked by the conductive film is completely avoided, the conductive film does not need to be exposed and developed, and the conductive film does not need to have photosensitive performance, the performance requirement on the conductive film is reduced, and the cost is saved; in the existing fine circuit board manufacturing process, products need to be kept stand for a period of time according to process requirements after a conductive film is coated and before exposure and development are carried out, but compared with the existing fine circuit board manufacturing process, the fine circuit board manufacturing process provided by the invention omits the flow of exposure and development of the conductive film, omits the time of exposure operation and development operation and the standing time brought by exposure and development, and shortens the production period of the products; the process flow design is simple, ingenious, reasonable and easy to realize, and compared with the existing EP process, the cost of water, electricity, materials and the like, the equipment cost and the labor cost are reduced.

Drawings

The invention is further illustrated below with reference to the figures and examples.

FIG. 1 is a flow chart of a method for manufacturing an improved multi-layer fine circuit board according to the present invention.

In the figure: 1. a polyimide; 2. gluing; 3. copper foil; 4. drying the film; 5. an aperture; 6. a conductive film; 7. a conductive substance; 8-hole copper.

Detailed Description

The manufacturing method of the improved multi-layer fine circuit board shown in figure 1 is characterized in that: the method comprises the steps of firstly pressing a dry film, exposing, developing, etching and stripping the film to form a circuit, then coating a layer of conductive film on the product except for a plating lead, then drilling, hole conductivity and copper plating to form a via hole, then reacting copper deposited on the conductive film through microetching liquid, and finally stripping all the conductive films on the product through stripping liquid.

The method comprises the following steps:

step A: laminating a dry film 4 on the outer side of the product copper foil 3; here, the dry film 4 functions as an etching resist, i.e., protects the copper foil 3 covered therewith from being etched during etching;

and B: exposing and developing, wherein the product is subjected to polymerization reaction of the dry film 4 irradiated by ultraviolet rays after the dry film 4 is pressed, the process is called exposure, the exposed product is subjected to developing treatment, the developing solution dissolves active groups of the unexposed part of the dry film 4, and the exposed part of the dry film cannot swell;

and C: etching is carried out, and the copper foil 3 exposed during development is bitten off by the etching solution;

step D: stripping, namely, enabling the product to enter a stripping groove, and cracking and separating the residual exposed dry film from the surface of the product under the action of a stripping agent;

step E: coating a layer of conductive film 6 on the product;

step F: laser drilling 5;

step G: after the hole 5 is formed, conducting treatment is carried out, and a conducting substance 7 is attached to the hole wall;

step H: plating hole copper 8;

step I: microetching to remove copper deposited on conductive film 6;

step J: the remaining conductive film 6 is peeled off.

The product is a multilayer fine circuit board.

The conductive film 6 has viscosity and conductivity, and is not attacked or dissolved by a chemical solution during hole conduction and hole copper plating, and is easy to peel off.

The step E is to avoid the plated lead when coating the conductive film 6.

And step F, forming the hole 5 meeting the specification at the specified position under the instantaneous action of the high-energy laser beam.

The invention has the beneficial effects that: the conductive film is coated and then drilled, so that the problem that the hole is blocked by the conductive film is completely avoided, the conductive film does not need to be exposed and developed, and the conductive film does not need to have photosensitive performance, the performance requirement on the conductive film is reduced, and the cost is saved; in the existing fine circuit board manufacturing process, products need to be kept stand for a period of time according to process requirements after a conductive film is coated and before exposure and development, but compared with the existing fine circuit board manufacturing process, the fine circuit board manufacturing process provided by the invention omits the flow of exposure and development of the conductive film, omits the time of exposure operation and development operation and the standing time caused by exposure and development, and shortens the production period of the products; the process flow design is simple, ingenious, reasonable and easy to realize, and compared with the existing EP process, the cost of water, electricity, materials and the like, the equipment cost and the labor cost are reduced.

Claims

1. A manufacturing method of an improved multi-layer fine circuit board is characterized in that: firstly, pressing a dry film, exposing, developing, etching and stripping the film to form a circuit on a product, coating a layer of conductive film on the product except an electroplating lead, then drilling, hole conducting and copper plating to form a via hole, then reacting copper deposited on the conductive film by using a microetching solution, and finally stripping all the conductive films on the product by using a stripping solution;

the method comprises the following steps:

step A: laminating a dry film (4) on the outer side of the product copper foil (3);

and B: carrying out exposure and development;

and C: etching is carried out;

step D: stripping the film;

step E: coating a conductive film (6) on the product;

step F: laser drilling (5);

step G: after the hole (5) is formed, conducting treatment is carried out, and a conducting substance (7) is attached to the hole wall;

step H: plated hole copper (8);

step I: microetching to remove copper deposited on the conductive film (6);

step J: the remaining conductive film (6) is peeled off.

2. The method of claim 1 for making an improved multilayer fine circuit board, wherein: the conductive film (6) has viscosity and conductivity, is not attacked and dissolved by a liquid medicine when the hole is conducted and plated with copper, and is easy to peel off.

3. The method of claim 1 for making an improved multilayer fine circuit board, wherein: and E, coating the conductive film (6) while avoiding the electroplated lead.

4. The method of claim 1 for making an improved multilayer fine circuit board, wherein: and F, forming a hole (5) meeting the specification at a specified position under the instantaneous action of the high-energy laser beam.