Title:
銀電気めっき浴
Document Type and Number:
Japanese Patent JP4138171
Kind Code:
B2
Abstract:
PURPOSE: To realize high speed plating in which cathode current density is controlled to the specified value or above and to reduce the dispersion of plating thickness by allowing the bath to contain silver potassium cyanide, nitrates, phosphates and free cyanides by specified concns., controlling the content ratio between nitrates and phosphates to a specified value by weight ratio and controlling the pH to a specified value. CONSTITUTION: This silver electroplating bath contains 40 to 250 g/L silver potassium cyanide, 50 to 300 g/L nitrates, 20 to 200 g/L phosphates and 0.01 to 25 g/L free cyanides in which the content ratio between nitrates and phosphates is (1:1) to (6:1) by weight ratio, pH is controlled to 8 to 12, and high speed plating of >=200 A/dm2 cathode current density is possible. As the nitrates to be used, potassium nitrate, sodium nitrate, ammonium nitrate or the like can be cited. As the phosphates to be used, potassium hydrogen phosphate, potassium dihydrogen phosphate, tripotassium phosphate, sodium hydrogen phosphate, sodium dihydrogen phosphate, trisodium phosphate, potassium pyrophosphate or the like can be cited.
Inventors:
Kato Yasuo
Application Number:
JP22821199A
Publication Date:
August 20, 2008
Filing Date:
August 12, 1999
Export Citation:
Assignee:
NE Chemcat Co., Ltd.
International Classes:
C25D3/46; C25D3/64
Domestic Patent References:
| JP61195986A | ||||
| JP55091994A | ||||
| JP52078635A | ||||
| JP7233496A | ||||
| JP60159193A |
Attorney, Agent or Firm:
Yasuyo Takahata