Separation of alpha emitting species from plating baths

Patent metadata

Field	Value
Publication number	US-10138568-B2
Application number	US-201815884572-A
Country	US
Kind code	B2
Filing date	Jan 31, 2018
Priority date	Nov 24, 2015
Publication date	Nov 27, 2018
Grant date	Nov 27, 2018

Abstract

A plating product fabrication method includes forming a first concentrate. The concentrate includes a Tin (Sn) species and a trace amount of Polonium (Po) species. The plating product fabrication method also includes creating a circuit between a filtering anode and a filtering cathode and reducing the Po species from the concentrate by plating Po upon the filtering cathode. In this manner, a purified Sn concentrate is formed. The purified Sn concentrate may be utilized to plate Sn upon a plating cathode. The purified Sn concentrate may be utilized to form purified Sn.

First claim

What is claimed is:

1. A plating product fabrication method comprising:
forming a first concentrate, the concentrate comprising a Tin (Sn) species and a trace amount of a Polonium (Po) species;
creating a circuit between a filtering anode and a filtering cathode; and
reducing the Po species from the concentrate by plating the Po species upon the filtering cathode.

2. The method of claim 1 , wherein a pulse and reverse pulse current is passed through the circuit to plate the Po species upon the filtering cathode.

3. The method of claim 2 , wherein reducing the Po species from the concentrate by plating the Po species upon the filtering cathode comprises forming a first purified concentrate comprising the Sn species and a reduced amount of the Po species relative to the first concentrate.

4. The method of claim 3 , further comprising:
subsequently plating the Sn species of the first purified concentrate upon a plating cathode.

5. The method of claim 4 , further comprising:
testing an alpha particle emission rate of the Sn species plated upon the plating cathode from the first purified concentrate (plated Sn species).

6. The method of claim 5 , further comprising:
if the alpha particle emission rate exceeds a predetermined maximum threshold, forming a second concentrate comprising the plated Sn species.

7. The method of claim 1 , wherein plating the Po species upon the filtering cathode comprises forming a purified Sn.

8. The method of claim 7 , further comprising:
forming a plating bath comprising the purified Sn.

Assignees

• IBM

Inventors

• Arvin Charles L
• Gordon Michael S

Classifications

• H10P74/207

  Electrical properties, e.g. testing or measuring of resistance, deep levels or capacitance-voltage characteristics · CPC title

• H10P14/47

  Electrolytic deposition, i.e. electroplating; Electroless plating · CPC title

• H10W72/01235

  by plating, e.g. electroless plating or electroplating · CPC title

• H10W72/012

  of bump connectors, dummy bumps or thermal bumps · CPC title

• C25D5/02

  Electroplating of selected surface areas · CPC title