Using 30% concentrations of hydrogen peroxide (hydrogen peroxide) and industrial hydrochloric acid according to the preparation of 1:3 corrosion liquid is a good way to make printed circuit boards. But in the production of notes and methods are not specified, the following in accordance with practical experience to make a supplementary explanation.
I. matters that must be paid attention to
This method has a small amount of chlorine gas released during the corrosion reaction. The operation should be carried out in a ventilated place. The operator is best to stand on the upper air outlet to avoid chlorine poisoning.
The reaction rate of corrosive liquid, should be strictly in accordance with the proportion and operation method of preparation, if the proportion is too improper, resulting in boiling liquid water overflow out, caused the accident.
It is better to use glass trays to contain corrosive liquid, so as to observe the corrosion condition at any time.
Two, corrosion liquid matching production method
The industrial hydrogen peroxide (H2O2) concentration of 31qo and the industrial hydrochloric acid and water with a concentration of 37% were prepared according to the ratio of 1:3:4. The operation should first put four water into the dish, then pour in three hydrochloric acid, and then slowly adding a hydrogen peroxide with a glass rod to stir, stir with a glass rod, can put the foil printed into the corrosive liquid, about five minutes after corrosion. Remove the corroded copper foil and put it into the water immediately. Rinse and dry it before using it. In the process of corrosion, the circuit board can be moved to speed up the corrosion.
Three. The concentration of hydrogen peroxide and hydrochloric acid
In chemical stores, the concentration of purchased products is greater than the required concentration, and is not suitable for direct distribution. Then, how to dilute it? Solution dilution method and calculation method are as follows: size molecular difference divided by small molecules, and then take the amount of solution, then have to add water.
Compared with ferric chloride, this method has the advantages of fast corrosion, low cost and simple operation. The utility model is especially suitable for making large-area printed circuit boards. Even if the first use of this method of production of personnel, as long as the operation requirements can also produce beautiful and beautiful circuit boards.