| 摘要 |
PROBLEM TO BE SOLVED: To prevent desmearing property of a desmear treatment liquid from decreasing greatly by adding a benzene carboxylic acid compound into alkaline permanganate desmear treatment liquid. SOLUTION: A halogen-free substrate is subjected to copper foil etch-out for eliminating a copper foil layer on both surfaces, the degree of elution of a skeleton constituent is accelerated at a test piece, and the test piece is dipped into a swelling agent for a printed-circuit board at 75 deg.C for seven minutes for swelling. Then, after the test piece has been washed in water, desmear treatment is made. In the desmear treatment permanganate potassium and alkaline agent are dissolved in water so as to prepare 13 vol.% concentration, and further a benzoic acid is dissolved at a specific concentration as a benzene carboxylic acid compound, thus preparing a desmear treatment liquid and hence easily determining desmear conditions to an optimum state.
|
