阅读说明：本技术 一种用于pcb除胶的溶胀剂及其制备方法 (Swelling agent for PCB degumming and preparation method thereof ) 是由 张波 张尚荣 彭世雄 陈广 于 2019-10-09 设计创作，主要内容包括：本发明公开了一种用于PCB除胶的溶胀剂,该溶胀剂由高沸点醇类化合物、高沸点酮类化合物、高沸点酯类化合物的混合物组成；本发明的溶胀剂组合对不同Tg的树脂板的树脂都具有较强的膨松能力且不同TG(低、中、高)值有相似的除胶速率,能够轻易的配合高锰酸盐除去树脂残渣,进而得到蜂窝状的树脂层,大大的增加了后续镀铜层与树脂层的结合力；本发明的溶胀剂用于PCB除胶只需一次除胶,操作方便,除胶效果好。(The invention discloses a swelling agent for PCB degumming, which consists of a mixture of high-boiling-point alcohol compounds, high-boiling-point ketone compounds and high-boiling-point ester compounds; the swelling agent combination has stronger bulkiness for resins of resin plates with different Tgs and similar degumming rates for different Tgs (low, medium and high), and can be easily matched with permanganate to remove resin residues so as to obtain a honeycomb-shaped resin layer, thereby greatly increasing the binding force between a subsequent copper plating layer and the resin layer; the swelling agent is used for removing the glue of the PCB only once, is convenient to operate and has a good glue removing effect.)

1. The swelling agent for PCB degumming is characterized in that the swelling agent comprises a mixture of high-boiling-point alcohol compounds, high-boiling-point ketone compounds and high-boiling-point ester compounds;

the high-boiling-point alcohol compound is an alcohol compound with a boiling point higher than 100 ℃, the high-boiling-point ketone compound is a ketone compound with a boiling point higher than 100 ℃, and the high-boiling-point ester compound is an ester compound with a boiling point higher than 100 ℃;

wherein: 5-35% of high-boiling-point alcohol compound, 5-25% of ketone compound, 5-25% of high-boiling-point ester compound and the balance of water.

2. The swelling agent for PCB degumming according to claim 1, wherein said high boiling point alcohol compounds comprise at least one of dipropylene glycol dimethyl ether, ethylene glycol butyl ether, diethylene glycol dimethyl ether, ethylene glycol, diethylene glycol monobutyl ether.

3. The swelling agent for PCB degumming according to claim 2, wherein the high boiling point ketone compounds comprise at least one of N-methyl pyrrolidone, 2-pyrrolidone, polyvinylpyrrolidone, acetylacetone.

4. The swelling agent for PCB degumming according to claim 3, wherein the high boiling point ester compound comprises at least one of butyl lactone, ethylene glycol butyl ether acetate, diethylene glycol butyl ether acetate.

5. The swelling agent for PCB degumming according to claim 4, wherein the high boiling point alcohol compounds are dipropylene glycol dimethyl ether, ethylene glycol, the high boiling point ketone compounds comprise N-methyl pyrrolidone, and the high boiling point ester compounds are butyrolactone; wherein: 20% by mass of dipropylene glycol dimethyl ether, 5% by mass of ethylene glycol, 10% by mass of N-methylpyrrolidone, 5% by mass of butyrolactone, and the balance of water.

6. The swelling agent for PCB degumming according to claim 4, wherein the high boiling point alcohol compounds are ethylene glycol butyl ether, diethylene glycol, the high boiling point ketone compounds comprise 2-pyrrolidone, and the high boiling point ester compounds are ethylene glycol butyl ether acetate; wherein: 25% of ethylene glycol butyl ether, 5% of diethylene glycol, 10% of 2-pyrrolidone, 5% of ethylene glycol butyl ether acetate and the balance of water.

7. The swelling agent for PCB degumming according to claim 4, wherein the high boiling point alcohol compounds are ethylene glycol butyl ether, diethylene glycol, the high boiling point ketone compounds comprise N-methyl pyrrolidone, polyvinyl pyrrolidone, and the high boiling point ester compounds are ethylene glycol butyl ether acetate; wherein: 15 percent of diethylene glycol dimethyl ether, 10 percent of N-methyl pyrrolidone, 15 percent of polyvinyl pyrrolidone, 10 percent of diethylene glycol butyl ether acetate and the balance of water.

8. The swelling agent for PCB degumming according to claim 4, wherein the high boiling point alcohol compounds are diethylene glycol monobutyl ether and ethylene glycol, the high boiling point ketone compounds are polyvinylpyrrolidone, and the high boiling point ester compounds are ethylene glycol butyl ether acetate; wherein: 15% of diethylene glycol monobutyl ether, 10% of ethylene glycol, 15% of polyvinylpyrrolidone and 5% of ethylene glycol monobutyl ether acetate.

9. The swelling agent for PCB degumming according to claim 4, wherein the high boiling point alcohol compounds are diethylene glycol monobutyl ether, ethylene glycol, the high boiling point ketone compounds are acetylacetone, and the high boiling point ester compounds are ethylene glycol butyl ether acetate; wherein: 15% of diethylene glycol monobutyl ether, 10% of ethylene glycol, 10% of acetylacetone and 15% of ethylene glycol monobutyl ether acetate.

10. The method for preparing the swelling agent for PCB degumming according to any of the claims 1-9, comprising the steps of: firstly, mixing water and an alcohol compound at room temperature, uniformly stirring, then adding a ketone compound, uniformly stirring, then adding an ester compound, uniformly stirring, and fixing the volume to obtain the swelling agent.

Technical Field

The invention belongs to the field of printed circuit boards, and relates to a swelling agent for PCB degumming and a north-middle method thereof.

Background

With the advent of the 5G era, the development of the PCB industry is rapid, and the requirements of the PCB are diversified. The diversification of the wiring boards means that different resin materials are required as substrates to satisfy the requirements of each function, and the different resin Tg (glass transition temperature) values are different, and the difficulty of removing residues left after drilling and forming honeycombs is different.

The process of removing the resin residue left after drilling the wiring board to form a honeycomb shape is called glue removal. Firstly, swelling resin residues in the through holes by using a swelling agent, then removing the swollen resin in the holes by using a permanganate alkaline solution to form a uniform honeycomb shape, and finally removing manganese and compounds thereof remained on a resin plate. The quality of the resin plate glue residue removing effect directly influences the quality of subsequent hole metallization, the glue removing effect depends on the swelling effect of the swelling agent, and the resin in the holes can be removed only by the swelling agent and potassium permanganate after the swelling agent swells the resin.

The existing swelling agents are mainly divided into two main categories. The glue removing rate is 0.15-0.45mg/cm for medium and low Tg value (less than 170℃)²The glue removing effect on the high Tg (more than 170 ℃) resin plate is poor, and the glue removing speed is lower than 0.15mg/cm²(ii) a The other is suitable for high Tg resin plate, and the glue removing rate is 0.15-0.45mg/cm²But the glue removing rate of the middle and low Tg resin plates is too high and is more than 0.45mg/cm²Resulting in excessive glue removal and damage to the substrate. Different swelling agents can be selected for circuit board enterprises with uniform incoming materials according to different Tg values of the circuit boards; however, for circuit board enterprises with different incoming materials and all boards with various Tg values, a swelling agent suitable for a low Tg value is often used, and the boards with a high Tg value need to be degummed twice, so that the operation trouble is brought, and the yield is also influenced.

Disclosure of Invention

In order to solve the defects of the existing swelling agent, the invention aims to solve the problem that resin plates with different Tg (glass transition temperature) in the existing circuit board swelling technology need to use different swelling agents or different degumming procedures.

The swelling agent for PCB degumming comprises a mixture of high-boiling-point alcohol compounds, high-boiling-point ketone compounds and high-boiling-point ester compounds; the high-boiling point alcohol compound is an alcohol compound with a boiling point higher than 100 ℃, the high-boiling point ketone compound is a ketone compound with a boiling point higher than 100 ℃, and the high-boiling point ester compound is an ester compound with a boiling point higher than 100 ℃;

furthermore, the mass ratio of the high boiling point alcohol compound is 5-35 percent, the mass ratio of the ketone compound is 5-25 percent, the mass ratio of the high boiling point ester compound is 5-25 percent, and the balance is water.

Further, the high-boiling point alcohol compound comprises at least one of dipropylene glycol dimethyl ether, ethylene glycol butyl ether, diethylene glycol dimethyl ether, ethylene glycol, diethylene glycol and diethylene glycol monobutyl ether.

Further, the high-boiling-point ketone compound includes at least one of N-methylpyrrolidone, 2-pyrrolidone, polyvinylpyrrolidone, and acetylacetone.

Further, the high-boiling-point ester compound comprises at least one of butyl lactone, ethylene glycol butyl ether acetate and diethylene glycol butyl ether acetate.

Further, the high-boiling-point alcohol compounds are dipropylene glycol dimethyl ether and ethylene glycol, the high-boiling-point ketone compounds comprise N-methyl pyrrolidone, and the high-boiling-point ester compounds are butyrolactone; wherein: 20% by mass of dipropylene glycol dimethyl ether, 5% by mass of ethylene glycol, 10% by mass of N-methylpyrrolidone, 5% by mass of butyrolactone, and the balance of water.

Preferably, the high-boiling point alcohol compound is ethylene glycol butyl ether and diethylene glycol, the high-boiling point ketone compound comprises 2-pyrrolidone, and the high-boiling point ester compound is ethylene glycol butyl ether acetate; wherein: 25% of ethylene glycol butyl ether, 5% of diethylene glycol, 10% of 2-pyrrolidone, 5% of ethylene glycol butyl ether acetate and the balance of water.

Preferably, the high-boiling point alcohol compounds are ethylene glycol butyl ether and diethylene glycol, the high-boiling point ketone compounds comprise N-methyl pyrrolidone and polyvinyl pyrrolidone, and the high-boiling point ester compounds are ethylene glycol butyl ether acetate; wherein: 15 percent of diethylene glycol dimethyl ether, 10 percent of N-methyl pyrrolidone, 15 percent of polyvinyl pyrrolidone, 10 percent of diethylene glycol butyl ether acetate and the balance of water.

Preferably, the high-boiling point alcohol compound is diethylene glycol monobutyl ether and ethylene glycol, the high-boiling point ketone compound is polyvinylpyrrolidone, and the high-boiling point ester compound is ethylene glycol monobutyl ether acetate; wherein: 15% of diethylene glycol monobutyl ether, 10% of ethylene glycol, 15% of polyvinylpyrrolidone and 5% of ethylene glycol monobutyl ether acetate.

Preferably, the high-boiling point alcohol compound is diethylene glycol monobutyl ether and ethylene glycol, the high-boiling point ketone compound is acetylacetone, and the high-boiling point ester compound is ethylene glycol monobutyl ether acetate; wherein: 15% of diethylene glycol monobutyl ether, 10% of ethylene glycol, 10% of acetylacetone and 15% of ethylene glycol monobutyl ether acetate.

Further, the invention also comprises a preparation method of the swelling agent for PCB degumming, which comprises the following steps: firstly, mixing water and an alcohol compound at room temperature, uniformly stirring, then adding a ketone compound, uniformly stirring, then adding an ester compound, uniformly stirring, and fixing the volume to obtain the swelling agent.

Has the advantages that: the combination of the alcohol-containing compound, the ketone compound and the ester compound is used as the swelling agent, so that the resin board with different Tg can be swelled, and the resin residue after swelling can be easily removed by potassium permanganate, so that the hole wall is cellular; the method can be suitable for different circuit boards, and different swelling agents do not need to be selected according to different Tg values of the circuit boards; only need once to remove the glue, convenient operation removes gluey effectual.

Drawings

FIG. 1 is an SEM image of the plate material of example 1 with glue removed;

FIG. 2 is an SEM image of the removed glue of each plate in comparative example 1.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

The swelling agent for PCB degumming comprises a mixture of high-boiling-point alcohol compounds, high-boiling-point ketone compounds and high-boiling-point ester compounds; the high boiling point alcohol compound is an alcohol compound with a boiling point higher than 100 ℃, the high boiling point ketone compound is a ketone compound with a boiling point higher than 100 ℃, and the high boiling point ester compound is an ester compound with a boiling point higher than 100 ℃.

The preparation method of the swelling agent comprises the following steps: firstly, mixing water and an alcohol compound at room temperature, uniformly stirring, then adding a ketone compound, uniformly stirring, then adding an ester compound, uniformly stirring, and fixing the volume to obtain the swelling agent.

The swelling agent has the same process flow as the traditional circuit board degumming process in use, and the specific process flow is as follows: swelling (5-9min) → water washing → degumming (10-15min) → water washing → neutralization (4-6min) → water washing.

The glue removing rate calculation method comprises the following steps: baking the resin plate at 120 ℃ for 2h, and weighing and counting w 1; then the mixture is processed through a degumming process, then is baked for 2 hours at 120 ℃, and then is weighed and counted to be w2, and the degumming rate (mg/cm)²) (w1-w 2)/2S; (S is the area of the plate, and the glue removing rate is required to be 0.15-0.45mg/cm²) And checking the degumming effect by using an electron microscope.