Electrodeposition of soft gold from a thiosulfate-sulfite bath for electronics applications

Tetsuya Osaka, A. Kodera, T. Misato, Takayuki Homma, Y. Okinaka, O. Yoshioka

Research output: Contribution to journalArticle

81 Citations (Scopus)

Abstract

The possibility of electrodeposition of soft gold from a thiosulfate-sulfite bath was explored for electronics applications. The bath does not contain cyanide, and it is operated at a near neutral pH and a mildly elevated temperature. The bath is stable, does not undergo spontaneous decomposition without the addition of any stabilizer, and yields gold deposits with a hardness sufficiently low for use as gold bumps on semiconductor devices. Factors affecting the hardness were investigated in detail. It is shown that the use of high concentrations of the complexing agents and/or the addition of thallium(I) ions decreases both hardness and sulfur content of the deposit. The lowest Vickers hardness values achieved were approxiraately 80 kg mm-2 in the as-deposited state and 50 kg mm-2 after annealing at 350°C for 30 min in air. The relationship between hardness and microstructure of the deposit was also examined.

Original languageEnglish
Pages (from-to)3462-3469
Number of pages8
JournalJournal of the Electrochemical Society
Volume144
Issue number10
Publication statusPublished - 1997 Oct

Fingerprint

Thiosulfates
sulfites
Sulfites
Electrodeposition
electrodeposition
Gold
baths
Electronic equipment
hardness
Hardness
gold
deposits
electronics
Gold deposits
Thallium
Vickers hardness
Cyanides
thallium
cyanides
Semiconductor devices

ASJC Scopus subject areas

  • Electrochemistry
  • Surfaces, Coatings and Films
  • Surfaces and Interfaces

Cite this

Electrodeposition of soft gold from a thiosulfate-sulfite bath for electronics applications. / Osaka, Tetsuya; Kodera, A.; Misato, T.; Homma, Takayuki; Okinaka, Y.; Yoshioka, O.

In: Journal of the Electrochemical Society, Vol. 144, No. 10, 10.1997, p. 3462-3469.

Research output: Contribution to journalArticle

@article{fe9b75e0de004b808143b684fadb3993,
title = "Electrodeposition of soft gold from a thiosulfate-sulfite bath for electronics applications",
abstract = "The possibility of electrodeposition of soft gold from a thiosulfate-sulfite bath was explored for electronics applications. The bath does not contain cyanide, and it is operated at a near neutral pH and a mildly elevated temperature. The bath is stable, does not undergo spontaneous decomposition without the addition of any stabilizer, and yields gold deposits with a hardness sufficiently low for use as gold bumps on semiconductor devices. Factors affecting the hardness were investigated in detail. It is shown that the use of high concentrations of the complexing agents and/or the addition of thallium(I) ions decreases both hardness and sulfur content of the deposit. The lowest Vickers hardness values achieved were approxiraately 80 kg mm-2 in the as-deposited state and 50 kg mm-2 after annealing at 350°C for 30 min in air. The relationship between hardness and microstructure of the deposit was also examined.",
author = "Tetsuya Osaka and A. Kodera and T. Misato and Takayuki Homma and Y. Okinaka and O. Yoshioka",
year = "1997",
month = "10",
language = "English",
volume = "144",
pages = "3462--3469",
journal = "Journal of the Electrochemical Society",
issn = "0013-4651",
publisher = "Electrochemical Society, Inc.",
number = "10",

}

TY - JOUR

T1 - Electrodeposition of soft gold from a thiosulfate-sulfite bath for electronics applications

AU - Osaka, Tetsuya

AU - Kodera, A.

AU - Misato, T.

AU - Homma, Takayuki

AU - Okinaka, Y.

AU - Yoshioka, O.

PY - 1997/10

Y1 - 1997/10

N2 - The possibility of electrodeposition of soft gold from a thiosulfate-sulfite bath was explored for electronics applications. The bath does not contain cyanide, and it is operated at a near neutral pH and a mildly elevated temperature. The bath is stable, does not undergo spontaneous decomposition without the addition of any stabilizer, and yields gold deposits with a hardness sufficiently low for use as gold bumps on semiconductor devices. Factors affecting the hardness were investigated in detail. It is shown that the use of high concentrations of the complexing agents and/or the addition of thallium(I) ions decreases both hardness and sulfur content of the deposit. The lowest Vickers hardness values achieved were approxiraately 80 kg mm-2 in the as-deposited state and 50 kg mm-2 after annealing at 350°C for 30 min in air. The relationship between hardness and microstructure of the deposit was also examined.

AB - The possibility of electrodeposition of soft gold from a thiosulfate-sulfite bath was explored for electronics applications. The bath does not contain cyanide, and it is operated at a near neutral pH and a mildly elevated temperature. The bath is stable, does not undergo spontaneous decomposition without the addition of any stabilizer, and yields gold deposits with a hardness sufficiently low for use as gold bumps on semiconductor devices. Factors affecting the hardness were investigated in detail. It is shown that the use of high concentrations of the complexing agents and/or the addition of thallium(I) ions decreases both hardness and sulfur content of the deposit. The lowest Vickers hardness values achieved were approxiraately 80 kg mm-2 in the as-deposited state and 50 kg mm-2 after annealing at 350°C for 30 min in air. The relationship between hardness and microstructure of the deposit was also examined.

UR - http://www.scopus.com/inward/record.url?scp=0031246639&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0031246639&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0031246639

VL - 144

SP - 3462

EP - 3469

JO - Journal of the Electrochemical Society

JF - Journal of the Electrochemical Society

SN - 0013-4651

IS - 10

ER -