Chemical solubilizing agent for tin or tin alloy

• US 5,223,087 A
• Filed: 04/05/1990
• Issued: 06/29/1993
• Est. Priority Date: 04/18/1989
• Status: Expired due to Fees

• Current Assignee: Tokai Denka Kogyo K.K.
• Original Assignee: Tokai Denka Kogyo K.K.
• Inventors: Hirai, Akira, Itani, Katsutoshi
• Primary Examiner(s): Bell, Mark L.
• Assistant Examiner(s): EINSMANN, MARGARET V
• Application Number:
  US07/505,228
• Time in Patent Office: 1,181 Days
• Field of Search: 106/1.05, 156/656, 252/79.2, 252/79.3, 252/79.4
• US Class Current: 216/108
• CPC Class Codes: C22B 15/0008 by wet processes by flotation B03D
• CPC Class Codes: C23F 1/30 for etching other metallic material
• CPC Class Codes: C23F 1/44 Compositions for etching metallic material from a metallic material substrate of different composition

Abstract

A chemical solubilizing agent for tin or a tin alloy used for electroconductive materials is provided. Said chemical solubilizing agent is an acidic solution containing hydrogen peroxide and an inorganic acid and 0.5-50 g liter of said acidic solution of at least one nitrogen-containing compound selected from the group consisting of heterocyclic compounds not having a double bond in the respective heterocyclic rings, cyclopentylamines and cyclohexylamines.

Claims

1. In a method for selectively removing tin or tin alloy adhered to copper or a copper alloy by applying to the tin or tin alloy an effective amount of a chemical solubilizing agent, the improvement wherein said chemical solubilizing agent is an acidic solution containing hydrogen peroxide in a concentration range of from 1 to 10 g per liter, an inorganic acid in a concentration range from about 10 to about 300 g per liter, and 0.5 to 50 g per liter of at least one nitrogen containing compound selected from the group consisting of pyrrolidine, 2-pyrrolidone, hydantoin, piperidine, piperazine, cyclopentylamine, 1-methylcyclopentylamine, cyclohexylamine, 1-methylcyclohexylamine, and a lower alkyl substituted derivative thereof.

2. The method of claim 1, wherein said inorganic acid is sulfuric acid, nitric acid, phosphoric acid, sulfamic acid or hydrogen halide.

3. The method of claim 1 further containing at least one hydrogen peroxide stabilizing agent selected from the group consisting of alcohols, glycol ethers, ethers, aliphatic amines and acid amines.