Title: Electro-chemical corrosion of circular silicon cup
Application Number: 87103891 Application Date: 1987.05.27
Publication Number: 1017380 Publication Date: 1988.03.30
Approval Pub. Date: Granted Pub. Date: 1991.04.10
International Classifi-cation: C25F3/12,C25F3/14,C25F7/00
Applicant(s) Name: Xi-an Communiction Univ. Address:
Inventor(s) Name:
Attorney & Agent: XU WENQUAN
Abstract:
     This invention discloses a technological process of electro-chemical corrosion which is used for the corrosion of a circular silicon cup (silicon elastic membrane with circumferential support) for semiconductive silicon of piezo-resistive sensor. An aqueous solution of NH4F which gives off a low poison to mankind is adopted as the solution for electro-chemical corrosion. After the n face of silicon sheet having a n/n structure to be corroded is coated with an easily growing SO2 as the selected corrosion-cover film, it is then covered with a lower rubber ring of sufficiently large diameter which is pressed a perforated copper electrode of negative polarity and a copper electrode of positive polarity. Then the corrosive solution is sprayed into the perforated copper electrode of negative polarity, and gets incontact with the silicon sheet to be corroded, so the corrosion proceeds.
Time: 4