Tin or tin alloy plating solution

Patent metadata

Field	Value
Publication number	US-11162182-B2
Application number	US-201816757855-A
Country	US
Kind code	B2
Filing date	Oct 23, 2018
Priority date	Oct 24, 2017
Publication date	Nov 2, 2021
Grant date	Nov 2, 2021

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 phenyl-based surfactant formed of polyoxyethylene bisphenol ether represented by the General Formula (1); and (D) a leveling agent,here, in the Formula (1), X is CaH2a (a is 1 or 3) and m is 2 to 12.

First claim

The invention claimed is:

1. A method of forming a tin or tin alloy plating deposition layer comprising:
a step of forming the tin or tin alloy plating deposition layer on a substrate with vias having different via diameters by using a tin or tin alloy plating solution and applying a single current density to produce the tin or tin alloy deposition layer comprising a pattern having bumps with different bump diameters and a uniform height of the formed bumps,
wherein the tin or tin alloy plating solution consists of:
a soluble salt consisting of a stannous salt or a mixture of a stannous salt and a salt of a metal selected from copper, bismuth, nickel, antimony, indium, and zinc;
an acid selected from an organic acid and an inorganic acid or a salt thereof;
a surfactant;
a leveling agent; and
ion exchange water,
wherein the surfactant contains a phenyl-based surfactant and the phenyl-based surfactant is a polyoxyethylene bisphenol ether represented by General Formula (1),

in the Formula (1), X is C a H 2a (a is 1 or 3) and m is a value selected from 9 to 10,
the polyoxyethylene bisphenol ether has a mass average molecular weight of 1000 to 1100,
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. 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 plating deposition layer according to claim 1 .

3. A method for producing a circuit board using a bump formed by the method according to claim 2 .

4. A method of forming a tin or tin alloy plating deposition layer comprising:
a step of forming the tin or tin alloy plating deposition layer on a substrate with vias having different via diameters by using a tin or tin alloy plating solution and applying a single current density to produce the tin or tin alloy deposition layer comprising a pattern having bumps with different bump diameters and a uniform height of the formed bumps,
wherein the tin or tin alloy plating solution consists of:
a soluble salt consisting of a stannous salt or a mixture of a stannous salt and a salt of a metal selected from copper, bismuth, nickel, antimony, indium, and zinc;
an acid selected from an organic acid and an inorganic acid or a salt thereof;
a surfactant containing a phenyl-based surfactant;
a leveling agent;
ion exchange water; and
two or more of: a surfactant other than the phenyl-based surfactant; an antioxidant; and
an alcohol having 1 to 3 carbon atoms,
wherein
the phenyl-based surfactant is a polyoxyethylene bisphenol ether represented by General Formula (1),

in the Formula (1), X is C a H 2 a (a is 1 or 3) and m is a value selected from 9 to 10,
the polyoxyethylene bisphenol ether has a mass average molecular weight of 1000 to 1100,
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.

5. 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 plating deposition layer according to claim 4 .

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

• H05K3/346

  Solder materials or compositions specially adapted therefor · CPC title

• C25D3/60

  containing more than 50% by weight of tin · CPC title

• H05K3/188

  by direct electroplating · CPC title