Laser sintering of Ag nanopaste film and its application to bond-pad formation

Author

Niizeki, Tomotake ; Maekawa, Katsuhiro ; Mita, Mamoru ; Yamasaki, Kazuhiko ; Matsuba, Yorishige ; Terada, Nobuto ; Saito, Hiroshi

Author_Institution

JST Innovation Satellite, Tsukuba

fYear

2008

fDate

27-30 May 2008

Firstpage

1745

Lastpage

1750

Abstract

A novel coating technology by means of sintering the silver NanoPaste^reg by a laser beam has been proposed. The novelty lies in the use of a conventional NdYAG laser to metalize nanoparticles as an alternative to furnace sintering. Silver nanoparticles with 5 nm in average diameter dispersed in the the silver NanoPaste are successfully sintered on the Cu substrate by the proposed method. Laser sintering proceeds from the paste surface into the substrate, and the thickness of a peeling-free film is around 0.2 mum. Multi-step sintering by the repletion of spin coating and laser metallization enables us to make a thicker Ag pad of around 1 mum. No peeling of the laser-sintered Ag film from the substrate was observed. Its adhesive strength is higher than that of a furnace-sintered sample. The Ag film thus fabricated can be used as pads for wire bonding, being an alternative to electroplating.

Keywords

adhesion; laser sintering; lead bonding; metallic thin films; metallisation; nanoparticles; nanotechnology; silver; spin coating; Ag; adhesive strength; bond-pad formation; laser metallization; laser sintering; nanoparticles; nanopaste film; peeling-free film; spin coating; wire bonding; Bonding; Coatings; Furnaces; Laser beams; Laser sintering; Metallization; Nanoparticles; Silver; Substrates; Surface emitting lasers;

fLanguage

English

Publisher

ieee

Conference_Titel

Electronic Components and Technology Conference, 2008. ECTC 2008. 58th

Conference_Location

Lake Buena Vista, FL

ISSN

0569-5503

Print_ISBN

978-1-4244-2230-2

Electronic_ISBN

0569-5503

Type

conf

DOI

10.1109/ECTC.2008.4550216

Filename

4550216