| 摘要 |
<p>PROBLEM TO BE SOLVED: To remove smear of bare holes, which are formed on an electron circuit board by laser processing, by dry processing. SOLUTION: This method for removing smear of via holes is carried out by spraying a fluid Ar containing a liquefied inert gas in decreased pressure condition as to solidify at least a part of the liquefied inert gas into a fine particle Ar4, blowing the fine particle Ar4 on an electronic circuit board 1 on which via holes are formed by laser beam, and removing smear adhering at the time of forming the via holes. The diameter of the via holes is about 0.05-0.5 mm and the aspect ratio of the via hole is about 0.5 or higher.</p> |
