Separation of alpha emitting species from plating baths

Patent metadata

Field	Value
Publication number	US-10287702-B2
Application number	US-201816050760-A
Country	US
Kind code	B2
Filing date	Jul 31, 2018
Priority date	Nov 24, 2015
Publication date	May 14, 2019
Grant date	May 14, 2019

Abstract

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

First claim

What is claimed is:

1. A plating product fabrication method comprising:
forming a first concentrate, the concentrate comprising a metal species and a trace amount of an alpha emitting species;
creating a circuit between a filtering anode and a filtering cathode; and
reducing the alpha emitting species from the concentrate by plating the alpha emitting 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 alpha emitting species upon the filtering cathode.

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

4. The method of claim 3 , further comprising:
subsequently plating the metal 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 alpha emitting species plated upon the plating cathode from the first purified concentrate (plated alpha emitting 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 alpha emitting species.

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

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

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

• C25D17/001

  Apparatus specially adapted for electrolytic coating of wafers, e.g. semiconductors or solar cells · CPC title