×

Method of etching aluminum

  • US 4,297,184 A
  • Filed: 02/19/1980
  • Issued: 10/27/1981
  • Est. Priority Date: 02/19/1980
  • Status: Expired due to Term
First Claim
Patent Images

1. In a method of etching aluminum by applying an alternating electric current to aluminum which is in contact with an electrolyte containing hydrochloric acid, the improvement in which the alternating current has a wave form wherein the current rises rapidly from zero to a maximum, then subsequently decreases rapidly in a first stage to an intermediate value which is about one-third to about one-half of the maximum, and thereafter decreases more slowly to zero in a second stage, the ratio of time of the second stage to time of the first stage being in the range from 1 to 6, whereby higher capacitance values of the etched aluminum are obtained.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×