Claims
- 1. A method of electroplating a metallic substrate with silver, which comprises steps of subjecting the substrate to preplating under a cathode current density of 0.1 to 80 mA/dm.sup.2 in an aqueous solution containing silver ions of 0.001 to 0.02 mole/l and thiocyanic ions of 0.1 to 5 moles, and electroplating the substrate preplated with silver in an aqueous solution containing silver ions 0.04 to 0.8 mole/l, thiocyanic ions of 0.5 to 10 moles/l and a film-improving agent in an amount sufficient to suppress a local growth of silver deposition under a cathode current density of 0.5 to 10 A/dm.sup.2.
- 2. A method according to claim 1, wherein the substrate is copper.
- 3. A method according to claim 1, wherein the film-improving agent is at least one member selected from the group consisting of:
- ______________________________________Bromine ions (Br.sup.-) 1 .times. 10.sup.-3 to 0.1 mole/lIodine ions (I.sup.-) 1.2 .times. 10.sup.-4 to 1.2 .times. 10.sup.-3 mole/lSelenocyanic ions 5 .times. 10.sup.-4 to 1 .times. 10.sup.-2 mole/l(SeCN.sup.-)Cobalt ions (Co.sup.++) 5 .times. 10.sup.-6 to 5 .times. 10.sup.-3 mole/lStannic acid ions 1 .times. 10.sup.-4 to 1 .times. 10.sup.-2 mole/l(SnO.sub.3.sup.--)Thiourea (SC(NH.sub.2).sub.2) 5 .times. 10.sup.-5 to 5 .times. 10.sup.-3 mole/lTriethanol amine 1 .times. 10.sup.-3 to 1 mole/l((HOCH.sub.2 CH.sub.2).sub.3 N) 1 .times. 10.sup.-3 to 1 mole/lSelennic acid ions 5 .times. 10.sup.6 to 5 .times. 10.sup.-3 mole/l(SeO.sub.4.sup.--)______________________________________
- 4. A method according to claim 3, wherein the bromine ions are generated from dissolved AgBr, KBr or NaBr.
- 5. A method according to claim 3, wherein the iodine ions are generated from dissolved KI, NaI, AgI, RbI, or CsI.
- 6. A method according to claim 3, wherein the selenocyanic ions are generated from dissolved KSeCN or NaSeCN.
- 7. A method according to claim 3, wherein the selenic acid ions are generated from dissolved H.sub.2 SeO.sub.4, Ag.sub.2 SeO.sub.4, K.sub.2 SeO.sub.4 or Na.sub.2 SeO.sub.4.
- 8. A method according to claim 3, wherein the cobalt ions are generated from dissolved CoSO.sub.4, CoCl.sub.2 or CoSeO.sub.4.
- 9. A method according to claim 3, wherein the stannic acid ions (SnO.sub.3.sup.--) are generated from dissolved Na.sub.2 SnO.sub.3.
- 10. A method according to claim 1, wherein the silver ions are generated from dissolved AgCl, AgBr, AgI, AgSCN, Ag.sub.2 O, Ag.sub.2 CO.sub.3, Ag.sub.2 SO.sub.4, AgNO.sub.3, AgSCN, Ag.sub.2 SeO.sub.4, or AgCH.sub.3 COO.sub.3.
- 11. A method according to claim 1, wherein the thiocyanic ions are generated from dissolved KSCN, NaSCN, NH.sub.4 SCN, CsSCN, or RbSCN.
Priority Claims (2)
Number |
Date |
Country |
Kind |
51-10392 |
Feb 1976 |
JPX |
|
51-111768 |
Sep 1976 |
JPX |
|
CROSS REFERENCE TO THE RELATED APPLICATION
This is a continuation-in-Part of U.S. Ser. No. 765,787, filed Feb. 4, 1977, now abandoned.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
2783194 |
Nobel et al. |
Feb 1957 |
|
3984292 |
Culjkovic |
Oct 1976 |
|
Non-Patent Literature Citations (1)
Entry |
Domnikov, Metal Finishing (Apr., 1966) vol. 64, No. 4 pp. 57-59. |
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
765787 |
Feb 1977 |
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