阅读说明：本技术 提高线路板绿油表面绝缘性的方法及应用 (Method for improving surface insulativity of green oil of circuit board and application ) 是由 戴匡 于 2019-09-12 设计创作，主要内容包括：本发明提供了一种提高线路板绿油表面绝缘性的方法,在线路板的外层蚀刻工序后、湿绿油的工序前,对线路板进行等离子清洗能够提高线路板绿油表面的绝缘性能。其中,等离子清洗时,等离子体作为高度活跃微粒子与处理的线路板表面发生作用,并配合特定工序,即：在外层蚀刻后、湿绿油前进行等离子清洗处理,在一定程度上改善线路板表面特性,提高湿绿油后的线路板绿油表面的绝缘性能,而且等离子体能够与线路板表层蚀刻后残留的污染物发生物理和/或化学反应,使被清洗物表面物质变成粒子和气态物资,经过抽真空排出,使得在湿绿油工序前线路板保持高度清洁,有利于绿油更均匀、紧密覆盖线路板表面,提高线路板的绝缘性能。(The invention provides a method for improving the surface insulation of green oil of a circuit board, which can improve the surface insulation of the green oil of the circuit board by carrying out plasma cleaning on the circuit board after the outer layer etching process of the circuit board and before the process of wetting the green oil. Wherein, during plasma cleaning, the plasma acts as highly active particles with the surface of the treated circuit board, and is matched with specific procedures, namely: after the outer layer is etched and before the wet green oil is subjected to plasma cleaning treatment, the surface characteristics of the circuit board are improved to a certain extent, the insulating property of the surface of the green oil of the circuit board after the wet green oil is improved, and the plasma can perform physical and/or chemical reaction with the pollutants remained after the etching of the surface layer of the circuit board, so that the surface substances of the cleaned object are changed into particles and gaseous materials, and the particles and the gaseous materials are discharged through vacuumizing, so that the circuit board is kept highly clean before the wet green oil process, the green oil can be more uniformly and tightly covered on the surface of the circuit board, and the insulating property of the circuit board is improved.)

1. A method for improving the surface insulativity of green oil of a circuit board is characterized in that the circuit board is subjected to plasma cleaning after the step of etching the outer layer of the circuit board and before the step of wetting the green oil;

The plasma cleaning comprises the following steps: treating the surface of the circuit board by plasma formed by gas; wherein the gas comprises: at least one of hydrogen, oxygen, nitrogen, and methane.

2. The method for improving the surface insulation property of the circuit board green oil according to claim 1, wherein the gas is a mixed gas of oxygen and nitrogen.

3. The method for improving the surface insulation property of the circuit board green oil according to claim 2, wherein the volume ratio of the oxygen to the nitrogen in the mixed gas is 2: 1.

4. The method for improving the surface insulation property of the green oil of the circuit board according to claim 1, wherein the plasma cleaning is carried out by a plasma cleaning machine, and the steps comprise: vacuumizing, injecting gas, controlling pressure, forming plasma by the gas under the action of radio frequency current, carrying out chemical reaction on the plasma and the circuit board, stopping gas injection and discharging waste gas.

5. the method for improving the surface insulation property of the green oil of the circuit board according to claim 4, wherein the vacuumizing time is 2-5 min.

6. The method for improving the surface insulation property of the green oil of the circuit board according to claim 4, wherein the pressure is controlled as follows: the gas delivery pressure is controlled at 5-10 PSI.

7. a method for improving the surface insulation property of green oil of a circuit board according to any one of claims 1 to 6, wherein the etching of the outer layer of the circuit board is as follows: removing the film, etching the plate and removing the tin from the plate plated with copper and/or tin to form a circuit pattern; the etching speed is 4.5 +/-0.3 m/min, and the temperature is 50 +/-2 ℃.

8. The method for improving the surface insulation property of the circuit board green oil according to any one of claims 1 to 6, wherein the wet green oil is: and printing a layer of solder mask on the surface of the circuit which does not need to be welded on the circuit board, and carrying out plate grinding, screen printing, exposure, plate punching and curing.

9. The method for improving the surface insulation of the green oil of the circuit board according to claim 8, wherein the speed of the plate grinding is 2.2 ± 0.2m/min, the T number of the silk screen is 43T +61T, the exposure energy is 8-14 grids, the speed of the plate punching is 3.8 ± 0.4m/min, and the curing conditions are as follows: sequentially standing at 75 + -2 deg.C for 60 + -5min, 100 + -5 deg.C for 30 + -2 min, and 155 + -5 deg.C for 60 + -3 min.

10. A wiring board characterized in that the method for producing the wiring board comprises the method for improving the surface insulation of the green oil of the wiring board according to any one of claims 1 to 9.

Technical Field

The invention relates to the field of printed circuit boards, in particular to a method for improving the surface insulativity of green oil of a circuit board and application thereof.

Background

The PCB is a short name of a printed circuit board, is an important electronic component and has a very wide development prospect. No matter military aerospace communication or civil consumer electronics, the requirements of function diversification and high reliability are gradually increased, and the demand on a high-performance PCB is increased day by day, so that the PCB is designed to be thinner and thinner, line gaps of the line width are thinner and thinner, the insulation problem among conductors is prominent day by day, and the importance of solder resistance insulation is also increased. How to effectively improve the surface insulation of the PCB green oil is a problem which is urgently needed to be solved in the current PCB preparation process.

Disclosure of Invention

In view of the above, it is necessary to provide a method for improving the surface insulation of the green oil of the circuit board.

The invention provides a method for improving the surface insulativity of green oil of a circuit board. The specific technical scheme is as follows:

A method for improving the surface insulativity of green oil of a circuit board, after the process of etching the outer layer of the circuit board, before the process of wetting the green oil, carry on the plasma cleaning to the said circuit board;

The plasma cleaning comprises the following steps: treating the surface of the circuit board by plasma formed by gas; wherein the gas comprises: at least one of hydrogen, oxygen, nitrogen, and methane.

In some of these embodiments, the gas is a mixture of oxygen and nitrogen.

In some embodiments, the volume ratio of the oxygen gas to the nitrogen gas in the mixed gas is 2: 1.

In some embodiments, the plasma cleaning is performed using a plasma cleaning machine, comprising: vacuumizing, injecting gas, controlling pressure, forming plasma by the gas under the action of radio frequency current, carrying out chemical reaction on the plasma and the circuit board, stopping gas injection and discharging waste gas.

In some of these embodiments, the time period for evacuation is 2-5 min.

in some of these embodiments, the pressure control is: controlling gas delivery pressure 5-10PSI

In some embodiments, the etching of the outer layer of the circuit board is: removing the film, etching the plate and removing the tin from the plate plated with copper and/or tin to form a circuit pattern; the etching speed is 4.5 +/-0.3 m/min, and the temperature is 50 +/-2 ℃.

in some of these embodiments, the wet green oil is: and printing a layer of solder mask on the surface of the circuit which does not need to be welded on the circuit board, and carrying out plate grinding, screen printing, exposure, plate punching and curing.

In some embodiments, the speed of the grinding plate is 2.2+/-0.2m/min, the T number of silk screen printing is 43T +61T, the exposure energy is 8-14 grids, the speed of the punching plate is 3.8 +/-0.4 m/min, and the curing conditions are as follows: sequentially standing at 75 + -2 deg.C for 60 + -5min, 100 + -5 deg.C for 30 + -2 min, and 155 + -5 deg.C for 60 + -3 min. The invention also provides a circuit board, and the specific technical scheme is as follows:

A preparation method of the circuit board comprises the method for improving the surface insulation of the green oil of the circuit board.

Based on the technical scheme, the invention has the following beneficial effects:

The inventors of the present invention have found that the insulating property of the green oil surface of the wiring board can be improved by performing plasma cleaning on the wiring board after the outer layer etching process of the wiring board and before the wet green oil process. Wherein, during plasma cleaning, aiming at the characteristics of the surface of the circuit board, the plasma formed by adopting proper gas is taken as highly active corpuscle to act with the surface of the processed circuit board, and is matched with specific procedures, namely: after the outer layer is etched and before the wet green oil is subjected to plasma cleaning treatment, the surface characteristics of the circuit board are improved to a certain extent, the insulating property of the surface of the green oil of the circuit board after the wet green oil is improved, and the plasma can chemically react with the pollutants remained after the etching of the surface layer of the circuit board, so that the surface substances of the cleaned object are changed into particles and gaseous substances, and the particles and the gaseous substances are discharged through vacuumizing, so that the circuit board is kept highly clean before the wet green oil process, the green oil can be more uniformly and tightly covered on the surface of the circuit board, and the insulating property of the circuit board is improved.

Drawings

FIG. 1 is a schematic view of the process of the present invention;

FIG. 2 is a schematic diagram of the operation of the plasma cleaning machine.

Detailed Description

In order that the invention may be more readily understood, reference will now be made to the following more particular description of the invention, examples of which are set forth below. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. These embodiments are provided so that this disclosure will be thorough and complete. It is to be understood that the experimental procedures in the following examples, where specific conditions are not noted, are generally in accordance with conventional conditions, or with conditions recommended by the manufacturer. The various reagents used in the examples are commercially available.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

A method for improving the surface insulativity of green oil of a circuit board comprises the step of carrying out plasma cleaning on the circuit board after the step of etching the outer layer of the circuit board and before the step of wetting the green oil.

Preferably, the plasma cleaning is: forming plasma by the gas under the action of radio frequency current, and processing the surface of the circuit board through the plasma to obtain the circuit board. Plasma is a state of matter, also called the fourth state of matter, that is ionized into a plasma state by applying sufficient energy to the gas. The "active" components of the plasma include: the plasma is formed by gas under the action of radio frequency current, the surface of the circuit board is treated by the plasma, and the properties of the active components in the plasma and pollutants on the surface of the circuit board are subjected to physical or chemical reaction to convert the pollutants into particles and gaseous substances, so that the aim of cleaning is fulfilled.

Optionally, the gas for forming the plasma comprises: at least one of hydrogen, oxygen, nitrogen, and methane. Preferably, the gas is a mixed gas of hydrogen and oxygen. More preferably, the volume ratio of oxygen to nitrogen in the mixed gas is 2: 1.

In other embodiments, the injected gas may be one of hydrogen, oxygen, nitrogen and methane, or a mixture of two or more of them. The mixed gas in proper proportion generates ions during high-frequency discharge, organic substances attached to the substrate are gasified by the reaction of active molecules in plasma and organic substances during plasma irradiation, and thus, the cleaning effect is achieved without washing.

Preferably, the plasma cleaning is performed by using a plasma cleaning machine, and the steps include: vacuumizing, injecting gas, controlling pressure, forming plasma by the gas under the action of radio frequency current, carrying out chemical reaction on the plasma and the circuit board, stopping gas injection and discharging waste gas. The vacuum pumping in the first step enables the vacuum cavity of the plasma cleaning machine to form a certain negative pressure, and the vacuum pumping time is related to the degree of forming the negative pressure, so that the gas flow of injected gas and the gas conveying pressure are influenced. Preferably, the vacuumizing time is 2-5minn, and the gas delivery pressure is controlled to be more than or equal to 5 PSI. More preferably, the vacuum pumping time is 5min, and the gas delivery pressure value is controlled to be 5-10 PSI. Further preferably 5 PSI. Furthermore, the specific gas is mixed according to a certain proportion to form mixed gas, and the gas delivery pressure and the gas flow speed are combined to form plasma in the vacuum cavity, so that the relatively stubborn organic residues of the circuit board can be removed, the interaction effect of the plasma and the surface of the circuit board is improved, and the improvement of the insulating property is facilitated.

Wherein, the outer layer etching of the circuit board in the method comprises the following steps: removing the film, etching the plate and removing the tin from the plate plated with copper and/or tin to form a circuit pattern; the etching speed is 4.5 +/-0.3 m/min, and the temperature is 50 +/-2 ℃. Preferably, the etching rate is 4.5m/min and the temperature is 50 ℃.

In addition, the method carries out a wet green oil process after outer layer etching and plasma cleaning, and specifically, the wet green oil is as follows: and printing a layer of solder mask on the surface of the circuit which does not need to be welded on the circuit board, and carrying out plate grinding, screen printing, exposure, plate punching and curing.

Preferably, the speed of the grinding plate is 2.2+/-0.2m/min, the T number of silk screen printing is 43T +61T, the exposure energy is 8-14 grids, the speed of the punching plate is 3.8 +/-0.4 m/min, and the curing condition is as follows: sequentially standing at 75 + -2 deg.C for 60 + -5min, 100 + -5 deg.C for 30 + -2 min, and 155 + -5 deg.C for 60 + -3 min. More preferably, the speed of the plate grinding is 2.2m/min, the T number of silk screen printing is 61T, the energy of exposure is 11 grids, the speed of the plate punching is 3.8m/min, and the curing conditions are as follows: standing at 75 deg.C for 60min, at 100 deg.C for 30min, and at 155 deg.C for 60 min.

alternatively, commonly used green oil types such as Probimer 77MA series, Taiyo PSR-4000 series, DSR series, Nanya series, and the like commonly used automobile panel inks can be used, with Probimer 77MA series and Taiyo PSR-4000 series being preferred inks.

The present invention will be described in further detail with reference to specific examples.