Indium Corporation

Francis M Mutuku

Ning-Cheng Lee

Hongwen Zhang

Jie Geng

Fen Chen

Huaguang Wang

Samuel Lytwynec

Some implementations of the disclosure are directed to low melting temperature (e.g., liquidus temperature below 210° C.) SnIn solder alloys. A SnIn solder alloy may consist of: 8 to 20 wt % In; greater than 0 wt % to 4 wt % Ag; optionally, one or more of greater than 0 wt % to 5 wt % Sb, greater than 0 wt % to 3 wt % Cu, greater than 0 wt % to 2.5 wt % Zn, greater than 0 wt % to 1.5 wt % Ni, greater than 0 wt % to 1.5 wt % Co, greater than 0 wt % to 1.5 wt % Ge, greater than 0 wt % to 1.5 wt % P, and greater than 0 wt % to 1.5 wt % Mn; and a remainder of Sn.

SnIn solder alloys

Some implementations of the disclosure are directed to low melting temperature (e.g., liquidus temperature below 210° C.) SnBi or Snln solder alloys. A SnBi solder alloy may consist of 2 to 60 wt % Bi; optionally, one or more of: up to 16 wt % In, up to 4.5 wt % Ag, up to 2 wt % Cu, up to 12 wt % Sb, up to 2.5 wt % Zn, up to 1.5 wt % Ni, up to 1.5 wt % Co, up to 1.5 wt % Ge, up to 1.5 wt % P, and up to 1.5 wt % Mn; and a remainder of Sn. A Snln solder alloy may consist of: 8 to 20 wt % In; optionally, one or more of: up to 12 wt % Bi, up to 4 wt % Ag, up to 5 wt % Sb, up to 3 wt % Cu, up to 2.5 wt % Zn, up to 1.5 wt % Ni, up to 1.5 wt % Co, up to 1.5 wt % Ge, up to 1.5 wt % P, and up to 1.5 wt % Mn; and a remainder of Sn.

SnBi and SnIn solder alloys

Some implementations of the disclosure relate to a lead-free solder paste with mixed solder powders that is particularly suitable for high temperature soldering applications involving multiple board-level reflow operations. In one implementation, the solder paste consists of 10 wt % to 90 wt % of a first solder alloy powder, the first solder alloy powder consisting of an SnSbCuAg solder alloy that has a wt % ratio of Sn:Sb of 0.75 to 1.1; 10 wt % to 90 wt % of a second solder alloy powder, the second solder alloy powder consisting of an Sn solder alloy including at least 80 wt % of Sn; and a remainder of flux.

Lead-free solder paste with mixed solder powders for high temperature applications

Implementations of the disclosure are directed to a lead-free mixed solder powder paste suitable for low temperature to middle temperature soldering applications. The lead-free solder paste may consist of: an amount of a first solder alloy powder between 44 wt % and 83 wt %, the first solder alloy powder comprising Sn; an amount of a second solder alloy powder between 5 wt % to 44 wt %, the second alloy powder comprising Sn, where the first solder alloy powder has a liquidus temperature lower than a solidus temperature of the second solder alloy powder; and a remainder of flux. The solder paste may be used for reflow at a peak temperature below the solidus temperature of the higher solidus temperature solder powder but above the melting temperature of the lower solidus temperature one.

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Utica, NY, United States of America

Francis M Mutuku