阅读说明：本技术 印刷线路板在印刷前的处理工艺 (Treatment process of printed circuit board before printing ) 是由 刘程秀 于 2018-07-05 设计创作，主要内容包括：本发明涉及印刷线路板在印刷前的处理工艺,所述印刷线路板包括银浆贯孔印刷线路板、铜浆贯孔印刷线路板及银浆跨线印刷线路板,所述印刷线路板印刷前的处理工艺包括如下步骤盐酸型清洗液酸洗-加压循环溢流水洗-加压水洗-超声波浸水洗-高压水洗-市水或DI水洗-吸干基板表面水分-高风力冷风吹干基板及其孔内的水分-高温烘干-使用翻转冷却机对基板进行翻转冷却。优点本发明具有一是银浆与铜箔的接触电阻低,其单点接触盘接触电阻≤15mΩ,产品在经过热风整平工艺的高温冲击后,跨线阻值保持相对稳定,阻值变化率≤20%；二是银浆贯孔孔电阻小并且稳定,产品单孔阻值≤30mΩ/0.5mm贯孔孔径；三是贯孔孔内银浆形状好,无明显的银浆空洞存在。(The invention relates to a treatment process of a printed circuit board before printing, wherein the printed circuit board comprises a silver paste through hole printed circuit board, a copper paste through hole printed circuit board and a silver paste cross-line printed circuit board, and the treatment process of the printed circuit board before printing comprises the following steps of hydrochloric acid type cleaning solution pickling, pressurized circulating overflow water washing, pressurized water washing, ultrasonic wave soaking water washing, high-pressure water washing, city water or DI water washing, substrate surface moisture absorption, high-wind-force cold air drying of a substrate and moisture in the substrate, high-temperature drying and turnover cooling of the substrate by using a turnover cooling machine. The invention has the advantages that firstly, the contact resistance of the silver paste and the copper foil is low, the contact resistance of the single-point contact plate is less than or equal to 15m omega, the over-line resistance value of the product is relatively stable after the product is subjected to high-temperature impact of a hot air leveling process, and the resistance value change rate is less than or equal to 20 percent; secondly, the resistance of the silver paste through hole is small and stable, and the resistance of a single hole of the product is less than or equal to 30m omega/0.5 mm of the aperture of the through hole; thirdly, the shape of the silver paste in the through hole is good, and no obvious silver paste cavity exists.)

1. A treatment process before printing of a printed circuit board comprises a silver paste through hole printed circuit board, a copper paste through hole printed circuit board and a silver paste cross-line printed circuit board, and is characterized in that the treatment process before printing of the printed circuit board comprises the following steps of 1. a hydrochloric acid type cleaning solution is used for pickling the pickling solution, so that the pickling solution has the effects of degreasing and removing copper surface oxides, and the surface roughness of a copper foil of a substrate can be kept; 2, the pressure of the pressurized circulating overflow water washing spray is 2-4kg/Cm2, which aims at reducing the acid liquor content in the water tank by 3. the pressure of the pressurized water washing spray is 2-4kg/Cm2, which aims at further reducing the acid liquor content in the water tank; 4, removing residual acid liquor and dust in the holes of the substrate by ultrasonic immersion and water washing; 5, high-pressure water washing and spraying at the pressure of 9-14kg/Cm2 for further cleaning the copper surface and the holes of the substrate; washing with city water or DI water; 7, absorbing the moisture on the surface of the substrate; 8. drying the substrate and the moisture in the holes of the substrate by using high-wind-power cold air; drying the surface and the hole walls of the substrate at high temperature; 10. and (5) overturning and cooling the substrate by using an overturning cooler.

2. The process of claim I, wherein the turn-over cooler is mounted in the print booth.

3. The pre-printing treatment process of the printed wiring board as claimed in claim I, wherein the hydrochloric acid type cleaning solution is prepared by mixing an inorganic active agent, a glycol ether solvent and pure water, wherein the mass percent of the inorganic active agent is 8.59-2%, the mass percent of the glycol ether solvent is 3.59-8%, and the mass percent of the pure water is 83-85%.

Technical Field

The invention relates to a treatment process of a printed circuit board before printing.

Background

The traditional silver/copper paste through hole printed circuit board and silver paste cross-line printed circuit board are processed by dilute sulfuric acid solution or sulfuric acid type microetching solution pickling, mechanical polishing and brushing, circulating water washing, pressurized water washing, drying, overturning and cooling before printing. After the sulfuric acid type pickling solution is used for pickling, acid solution adsorbed on the inner wall of the hole is not easy to clean, and after the silver/copper paste is used for perforating, dried and solidified, the silver/copper paste in the hole is easy to generate a cavity, so that the resistance of the silver/copper paste perforating hole is increased, and the reliability of a product is influenced; the sulfuric acid type micro-etching solution is used, a clean copper surface can be obtained, but after the copper foil is subjected to micro-etching, the copper surface is relatively smooth and clean, the original roughness of the copper surface is avoided, and the bonding force between the silver/copper slurry and the copper foil can be reduced; in addition, sulfuric acid type solution is easy to volatilize, so that acid gas exists in the working environment, the copper surface of the substrate is easily subjected to secondary pollution of the acid gas in the processes of cleaning, drying, overturning and cooling, the binding force between the silver/copper slurry and the copper foil is influenced, the resistance value of the through hole is increased, and the reliability of a product is influenced; the mechanical polishing brush is used, so that the roughness of the surface of the copper foil can be increased, the binding force between the silver/copper paste and the copper foil is increased, but in the process of polishing and brushing the copper surface, copper powder is easy to enter the hole on the substrate and is difficult to clean, so that the silver/copper paste in the hole is easy to generate a cavity after the silver/copper paste is subjected to through hole, drying and curing, the resistance value of the through hole of the silver/copper paste is increased, and the reliability of a product is influenced.

Disclosure of Invention

The invention aims to solve the defects in the background art and provides a treatment process of a printed circuit board before printing. In order to achieve the purpose, the invention adopts the following technical scheme that the treatment process of the printed circuit board before printing comprises a silver paste through hole printed circuit board, a copper paste through hole printed circuit board and a silver paste cross-line printed circuit board, and comprises the following steps of 1. the pickling solution of hydrochloric acid type cleaning solution has the effects of degreasing and removing copper surface oxides and can keep the surface of the copper foil of the substrate rough; 2. the spraying pressure of the pressurized circulating overflow water washing is 2-4Kg/Cm2, which aims at reducing the acid liquor content in the water tank by 3. the spraying pressure of the pressurized water washing is 2-4Kg/Cm2, which aims at further reducing the acid liquor content in the water tank, 4. the residual acid liquor and dust in the holes of the substrate are removed by ultrasonic immersion water washing; 5. the high-pressure water washing spraying pressure is 9-14Kg/Cm2, which aims to further clean the copper surface and the holes of the substrate; 6. washing with city water or DI water; 7. absorbing the surface moisture of the substrate; 8. drying the substrate and the moisture in the holes of the substrate by using high-wind-power cold air; 9. drying the surface and the hole wall of the substrate at high temperature; 10. and (5) overturning and cooling the substrate by using an overturning cooler. For one optimization of the invention, the tumble cooler is installed in the printing booth. The hydrochloric acid type cleaning solution is prepared by mixing 8.59-12% by mass of an inorganic active agent, 3.5-8% by mass of a glycol ether solvent and 83-85% by mass of pure water. Compared with the background technology, the invention has the advantages that firstly, the contact resistance of the silver paste and the copper foil is low, the contact resistance of a single-point contact disc is less than 14M omega, the contact resistance of the product produced by the traditional technology is generally 19-30M omega, the trans-line resistance value of the product is relatively stable after the product is subjected to high-temperature impact of a hot air leveling technology, and the change rate of the resistance value is less than 20 percent, secondly, the resistance of the silver paste through hole is small and stable, the single-hole resistance value of the product is 30 pi iota omega/0.5 mm through hole diameter, and the single-hole resistance value of the product produced by the traditional technology is about; thirdly, the shape of the silver paste in the through hole is good, and no obvious silver paste cavity exists, while the product produced by the traditional process has more cavities in the through hole.

Detailed Description