Method of quantitative analysis of hexavalent chromium in chromate coating and method for controlling hazardous element in encapsulating resin of resin encapsulation semiconductor device

摘要

This invention relates to a method of quantitative analysis of hexavalent chromium in a chromate coating on a substrate. In this method a substrate on which the chromate coating is formed is immersed into an aqueous solution containing lithium hydroxide to extract hexavalent chromium within an extraction solution. Quantitative analysis of extracted hexavalent chromium in the extraction solution is then performed.

主权项

1. A method of quantitative analysis of hexavalent chromium in a chromate coating, the method comprising:
immersing a substrate on which a chromate coating is formed in an aqueous solution comprising lithium hydroxide at a concentration of from 0.8 to 1.3 wt % to extract hexavalent chromium, thereby forming an extraction solution; making the extraction solution acidic; and performing quantitative analysis of extracted hexavalent chromium in the extraction solution, wherein hexavalent chromium contained in the chromate coating is not reduced during the extraction of the hexavalent chromium.