Tin or tin alloy plating solution

Patent metadata

Field	Value
Publication number	US-11268203-B2
Application number	US-201816757872-A
Country	US
Kind code	B2
Filing date	Oct 23, 2018
Priority date	Oct 24, 2017
Publication date	Mar 8, 2022
Grant date	Mar 8, 2022

Abstract

A tin or tin alloy plating solution includes: (A) a soluble salt containing at least a stannous salt; (B) an acid selected from an organic acid and an inorganic acid or a salt thereof; (C) a surfactant; and (D) a leveling agent. In addition, the surfactant contains polyoxyethylene polyoxypropylene alkylamine, an alkyl group of the polyoxyethylene polyoxypropylene alkylamine is CaH2a+1 (where a is 12 to 18). Further, in a case where a number of a functional group of polyoxypropylene of the polyoxyethylene polyoxypropylene alkylamine is set as p and a number of a functional group of polyoxyethylene of the polyoxyethylene polyoxypropylene alkylamine is set as q, the sum of p and q (p+q) is 8 to 21, and a ratio of p to q (p/q) is 0.1 to 1.6.

First claim

The invention claimed is:

1. A method of forming a tin or tin alloy deposition layer comprising the step of forming a tin or tin alloy deposition layer on a substrate with vias having different via diameters by using a tin or tin alloy plating solution,
wherein the tin or tin alloy plaiting solution comprises:
(A) a soluble salt containing at least a stannous salt;
(B) an acid selected from an organic acid and an inorganic acid or a salt thereof;
(C) a surfactant; and
(D) a leveling agent,

wherein the surfactant contains polyoxyethylene polyoxypropylene alkylamine selected from the group consisting of general formulae (1), (3) and (4):

wherein R 1 represents C a H 2a−1 , a is an integer from 12 to 18, p and q are each 1 or more, a sum of p and q is an integer from 8 to 21, and
a ratio of p to q, p/q, is 0.1 to 1.6,
the leveling agent is made of a first leveling agent and a second leveling agent,
the first leveling agent is one or more selected from a group consisting of aliphatic aldehyde, aromatic aldehyde, aliphatic ketone and aromatic ketone, and
the second leveling agent is α,β-unsaturated carboxylic acid or α,β-unsaturated carboxylic acid amide, or a salt thereof.

2. The method of forming a tin or tin alloy plating deposition layer according to claim 1 , wherein the tin or tin alloy plating solution further comprises two or more of: a surfactant other than the surfactant; an antioxidant; and an alcohol having 1 to 3 carbon atoms.

3. A method for forming a bump comprising the step of performing a reflow process on the tin or tin alloy plating deposition layer formed by the method of forming a tin or tin alloy deposition layer according to claim 1 .

4. A method for producing a circuit board using the bump formed by the method according to claim 3 .

5. A method for forming a bump performing a reflow process comprising the step of performing a reflow process on the tin or tin alloy plating deposition layer formed by the method of forming a tin or tin alloy deposition layer according to claim 2 .

6. A method for producing a circuit board using the bump formed by the method according to claim 5 .

7. The method of forming a tin or tin alloy deposition layer according to claim 1 , wherein the tin or tin alloy deposition layer is formed by electroplating under a single current density.

8. The method of forming a tin or tin alloy deposition layer according to claim 1 , wherein the polyoxyethylene polyoxypropylene alkylamine is selected from the group consisting of general formulae (1) and (3).

Assignees

• Mitsubishi Materials Corp

Inventors

• Watanabe Mami
• SUSUKI Kyoka
• Nakaya Kiyotaka

Classifications

• H10W72/227

  Multiple bumps having different sizes · CPC title

• H10W72/012

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

• C25D7/00

  Electroplating characterised by the article coated · CPC title

• H05K2203/0338

  Transferring metal or conductive material other than a circuit pattern, e.g. bump, solder, printed component · CPC title

• H05K3/181

  by electroless plating (adhesives therefor H05K3/387) · CPC title