Au-sn alloy powder for solder paste
AssigneeMitsubishi Materials Corporation
InventorsMasayuki Ishikawa, Masayoshi Kohinata, Akihumi Mishima
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Abstract
The problem is to provide an Au—Sn alloy powder for use in producing an Au—Sn alloy solder paste having reduced generation of voids. The problem is solved by an Au—Sn alloy powder for a solder paste, which has a composition consisting of Sn of 20.5-23.5% by mass and a remainder containing Au and inevitable impurities, and which has a microstructure in which 0.5 to 30 area % of fine Sn-rich primary crystal phase regions having a diameter of 3 μm or less are crystallized in a matrix.
Claims4
An Au—Sn alloy powder for a solder paste, which has a composition consisting of Sn of 20.5-23.5% by mass and a remainder containing Au and inevitable impurities, and which has a microstructure in which 0.5 to 30 area % of -fine Sn-rich primary crystal phase regions having a diameter of 3 μm or less are crystallized in a matrix.
A method for producing an Au—Sn alloy powder, comprising the steps of:
- melting an Au—Sn alloy having a composition consisting of Sn of 20.5-23.5% by mass and a remainder containing Au and inevitable impurities to obtain a molten metal,
- subjecting the molten metal to mechanical stirring, and
- atomizing the molten metal during or after the mechanical stirring.
Dependencies are inferred from the claim text.