Electroless palladium plating solution and palladium film

Patent metadata

Field	Value
Publication number	US-11492706-B2
Application number	US-201916968981-A
Country	US
Kind code	B2
Filing date	Feb 15, 2019
Priority date	Feb 20, 2018
Publication date	Nov 8, 2022
Grant date	Nov 8, 2022

Abstract

An electroless palladium plating liquid containing at least hydrazine or a salt thereof as a reducing agent, which has excellent bath stability in the vicinity of acidity to neutrality range, long-term stability, and is capable of suppressing the Pd film deposition rate decrease caused by elution of etching resist. An electroless palladium plating solution of the invention includes a palladium compound, hydrazine or its salt, at least one selected from a group consisting of a compound represented by the following formula (1) or its salt and a compound represented by the following formula (2) or its salt; and a pH of 8 or less, NH2NHCOR1 (1), (NH2NHCO)2(R2)n (2), wherein R1 represents H, NH2, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, NHNH2, or an aromatic group, wherein each of these groups may have a substituent; R2 represents (CH2) or an aromatic group, wherein each of these groups may have a substituent; and n represents an integer of 0 to 10.

First claim

The invention claimed is:

1. An electroless palladium plating solution comprising:
a palladium compound;
hydrazine or its salt; and
at least one selected from a group consisting of
a compound represented by formula (1) or its salt, and
a compound represented by formula (2) or its salt; and

wherein the electroless palladium plating solution has a pH of 8 or less:
NH 2 NHCOR 1   formula (1),

(NH 2 NHCO) 2 (R 2 ) n   formula (2),

wherein R 1 represents H, NH 2 , an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, NHNH 2 , or an aromatic group, wherein each of these groups may have a substituent;
wherein n represents an integer of 0 to 10;
wherein the R 2 in the formula (2) represents CH 2 or an aromatic group, wherein each of these groups may have a substituent; and
wherein either
(i) when the R 2 represents CH 2 , n is 1, or
(ii) when the R 2 represents an aromatic group, n represents an integer of 1 to 10.

2. The electroless palladium plating solution according to claim 1 , further comprising a reducing agent other than hydrazine or its salt.

3. The electroless palladium plating solution according to claim 1 , wherein the reducing agent other than hydrazine or its salt is at least one selected from a group consisting of formic acid or its salt, hypophosphorous acid or its salt, and phosphorous acid or its salt.

Assignees

• Uemura Kogyo Kk

Inventors

• Sasamura Tetsuya
• Someya Tatsushi
• Tanabe Katsuhisa
• Wada Shinsuke
• FURUYA Eriko

Classifications

• C23C18/16

  by reduction or substitution, e.g. electroless plating (C23C18/54 takes precedence) · CPC title

• B32B9/041

  of metal · CPC title

• C23C18/44 Primary

  using reducing agents · CPC title