CN115279039A

CN115279039A - Laser imaging-based environment-friendly false positive PCB pattern manufacturing method

Info

Publication number: CN115279039A
Application number: CN202210697060.8A
Authority: CN
Inventors: 张本贤; 李志雄; 舒志迁; 魏和平; 陈蓁; 邱锡曼
Original assignee: Chengyi Electronics Jiaxing Co ltd
Current assignee: Chengyi Electronics Jiaxing Co ltd
Priority date: 2022-06-20
Filing date: 2022-06-20
Publication date: 2022-11-01

Abstract

The invention discloses a laser imaging-based pattern manufacturing method for an environment-friendly false positive PCB, which comprises the following manufacturing steps of cutting, drilling, conducting resin, VCP electroplating, pattern transfer, pattern etching, solder resistance, characters, tin spraying and forming, wherein: pattern electroplating, namely plating a tin layer of 3-5um on the PCB without plating copper; transferring the pattern, namely directly placing the PCB into laser imaging equipment for laser ablation; the method adopts laser direct ablation imaging, completely does not use traditional photosensitive coating materials, and fundamentally avoids the generation of environmental pollution caused by photosensitive coatings.

Description

Laser imaging-based environment-friendly false positive PCB pattern manufacturing method

Technical Field

The invention belongs to the technical field of PCB (printed circuit board) manufacturing, and particularly relates to a laser imaging-based environment-friendly false positive PCB pattern manufacturing method.

Background

PCB (Printed Circuit Board), which is called Printed Circuit Board in chinese, is an important electronic component, a support for electronic components, and a carrier for electrical interconnection of electronic components. It is called a "printed" circuit board because it is made using electronic printing.

The conventional PCB pattern manufacturing needs to use a wet film or a dry film photosensitive coating, the photosensitive coating can develop and remove an unexposed pattern area through sodium carbonate or potassium carbonate weak base with the mass concentration of about 1%, and the photosensitive coating can remove a film of an exposed pattern area through sodium hydroxide or potassium hydroxide with the mass concentration of about 5%. Because the main component of the photosensitive coating is an organic polymer compound, the TOC content in the wastewater is extremely high after the photosensitive coating is dissolved in developing and film removing chemicals, and a common PCB factory can control the TOC content of the wastewater within the discharge standard through a plurality of wastewater treatment process flows, but the enrichment phenomenon still occurs when the wastewater is discharged into the natural environment, so the wastewater still has the problem of environmental pollution to a certain extent.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a method for directly ablating and imaging by adopting laser, which completely does not use the traditional photosensitive coating material and fundamentally avoids the problem of environmental pollution caused by the photosensitive coating.

In order to realize the purpose, the invention provides the following technical scheme: a laser imaging-based method for manufacturing an environment-friendly false positive PCB pattern comprises the following manufacturing steps of cutting, drilling, conducting resin, VCP electroplating, pattern transfer, pattern etching, solder resistance, characters, tin spraying and forming, wherein:

pattern electroplating, namely plating a tin layer of 3-5um on the PCB without plating copper;

transferring the pattern, namely directly placing the PCB into laser imaging equipment for laser ablation;

and (4) pattern etching, namely, entering the board from a film removing section or a water washing section, and cleaning and removing residues after laser ablation in the pattern transfer in the step by adopting the washing pressure of the section.

Further in the step pattern plating, the current density was 9ASF, and the plating time was 10 minutes.

Further, in the step of pattern plating, the concentration of sulfuric acid is controlled to be 9 to 11 percent, and SnSO₄The concentration is controlled to be 30-40g/L, and the temperature of the plating bath is controlled to be 19-25 ℃.

Further, in the step of pattern transfer, the laser power of the laser imaging equipment is more than or equal to 20W.

Further, in the step of pattern etching, the spraying pressure is 2.5-3.5kg/cm²。

Further in the step of pattern etching, the plate is cleaned and then directly enters the alkaline etching section.

Further in the alkaline etching stage, the alkaline etching solution controls the concentration of Cu²⁺120g/L to 170g/L, cl^-175g/L to 220g/L, pH value of 8.0 to 8.8, specific gravity of 1.19 to 1.32 and temperature of 45 to 55 ℃.

Further, when the PCB passes through the alkaline etching section, the corresponding etching transmission speed is set according to the copper thickness electroplated by VCP, and the transmission speed is set to be slower when the copper thickness is thicker.

Compared with the prior art, the invention has the beneficial effects that: the method adopts laser to directly ablate and image, does not use the traditional photosensitive coating material at all, can avoid TOC environmental pollution problem caused by the photosensitive coating compared with the conventional PCB pattern manufacture, fundamentally avoids the generation of environmental pollution problem caused by the photosensitive coating, has simple pattern manufacture flow, and can save 50 to 60 percent of the pattern production cost compared with the conventional flow.

Detailed Description

In the description of the present invention, it should be noted that the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features. Thus, a definition of "a first" or "a second" feature may explicitly or implicitly include one or more of the features, and in the description of the invention, "a number" or "a number" means two or more unless explicitly specified otherwise.

Furthermore, if the terms "first" and "second" are used for descriptive purposes only, they are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature, and in the description of the invention, "plurality" or "a plurality" means two or more unless explicitly specifically defined otherwise.

A laser imaging-based pattern manufacturing method for an environment-friendly false positive PCB comprises the following manufacturing method flows of material cutting → drilling → conductive adhesive → VCP electroplating → pattern transfer → pattern etching → solder resist, characters → tin spraying → molding.

The 3 process flows of pattern transfer, pattern electroplating and pattern etching are different, and other flows are completely consistent with the prior art.

Specifically, the method comprises the following steps:

1. pattern electroplating, only plating a tin layer of about 3-5um without plating copper, wherein the step is different from the conventional positive PCB pattern electroplating, and the parameters of the tin layer electroplating, the current density of 9ASF and the electroplating time are 10 minutes; sulfuric acid concentration is controlled to be 9-11%, snSO₄The concentration is controlled to be 30-40g/L, and the temperature of the electroplating bath is 19-25 ℃.

2. And (4) transferring the pattern, and directly placing the plate into laser imaging equipment for laser ablation without pretreatment. Because the tin coating of electroplating is thinner, need pay attention to lightly putting in the operation process, preferred full-automatic board equipment of receive and release avoids manual operation scotch tin coating. Removing the tin electroplating layer in the area beyond the effective pattern through laser ablation; the laser power of the laser imaging device is recommended to be configured to be more than or equal to 20W, so that the production efficiency is improved.

3. Pattern etching, still entering the board from the film removing section or the water washing section, and cleaning and removing residues after laser ablation in the pattern transfer step by utilizing the flushing pressure of the section so as to avoid influencing the pattern etching effect, wherein the spraying pressure is recommended to be 2.5-3.5kg/cm². Cleaning the substrate, directly introducing into alkaline etching section, setting etching transfer rate according to VCP electroplated copper thickness, and setting transfer rate slower when the copper thickness is thicker to reach copper in non-effective circuit regionIs etched clean exactly to the optimum etch point. Alkaline etchant control concentration, cu²⁺120g/L to 170g/L, cl^-175g/L to 220g/L, pH value of 8.0 to 8.8, specific gravity of 1.19 to 1.32 and temperature of 45 to 55 ℃.

The method adopts laser to directly ablate and image, completely does not use the traditional photosensitive coating material, and fundamentally avoids the problem of environmental pollution caused by the photosensitive coating.

The invention can also have the step of electric measurement → final inspection → packaging after the step of molding, namely the whole manufacturing process is material cutting → drilling → conductive adhesive → VCP electroplating → pattern transfer → pattern etching → solder resist, character → tin spraying → molding → electric measurement → final inspection → packaging.

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and adaptations to those skilled in the art without departing from the principles of the present invention should also be considered as within the scope of the present invention.

Claims

1. The laser imaging-based pattern manufacturing method for the environment-friendly false positive PCB is characterized by comprising the following manufacturing steps of cutting, drilling, conducting resin, VCP electroplating, pattern transfer, pattern etching, solder resistance, characters, tin spraying and forming, wherein:

and pattern etching, namely, putting the pattern into a board from a film removing section or a water washing section, and cleaning and removing residues after laser ablation in the pattern transfer by adopting the washing pressure of the section.

2. The laser imaging-based environment-friendly false positive PCB pattern manufacturing method of claim 1, wherein: in the step pattern plating, the current density was 9ASF, and the plating time was 10 minutes.

3. The laser imaging-based environment-friendly false positive PCB pattern manufacturing method of claim 2, characterized in that: in the step of pattern plating, the concentration of sulfuric acid is controlled to be 9 to 11 percent, and SnSO₄The concentration is controlled to be 30-40g/L, and the temperature of the plating bath is controlled to be 19-25 ℃.

4. The laser imaging-based environment-friendly false positive PCB pattern manufacturing method of claim 3, wherein: in the step of pattern transfer, the laser power of the laser imaging equipment is more than or equal to 20W.

5. The laser imaging-based environment-friendly false positive PCB pattern manufacturing method of claim 4, wherein: in the step of pattern etching, the spray pressure is 2.5-3.5kg/cm²。

6. The laser imaging-based environment-friendly false positive PCB pattern manufacturing method of claim 5, wherein: in the step of pattern etching, the plate is cleaned and then directly enters the alkaline etching section.

7. The laser imaging-based environment-friendly false positive PCB pattern manufacturing method of claim 6, wherein: in the alkaline etching section, the alkaline etching solution controls the concentration of Cu²⁺120g/L to 170g/L, cl^-175g/L to 220g/L, pH value of 8.0 to 8.8, specific gravity of 1.19 to 1.32 and temperature of 45 to 55 ℃.

8. The laser imaging-based environment-friendly false positive PCB pattern manufacturing method of claim 7, wherein: when the PCB board passes through the alkaline etching section, the corresponding etching transmission speed is set according to the copper thickness electroplated by the VCP, and the transmission speed is set to be slower when the copper thickness is thicker.