Lead-Free, Silver-Free Solder Alloys
A lead-free, silver-free solder alloy includes 0.001 to 0.800% by weight copper, 0.080 to 0.120% by weight bis muth, 0.030 to 0.050% by weight nickel, 0.008 to 0.012% by weight phosphorus, and balance tin, together with unavoidable impurities. The solder alloy can be in the form of one of a bar, a stick, a solid or flux cored wire, a foil or strip, or a powder or paste, or solder spheres for use in ball grid arrays or chip scale packages, or other pre-formed solder pieces. The solder alloy can be used to create a solder joint between an electronic component and a pad of an electronic substrate.
1 . A lead-free, silver-free solder alloy comprising:
0.001 to 0.800% by weight copper;
0.080 to 0.120% by weight bismuth;
0.030 to 0.050% by weight nickel;
0.008 to 0.012% by weight phosphorus; and
balance tin, together with unavoidable impurities.
2 . The solder alloy of claim 1 , further comprising one or more of the following:
0.10% by weight maximum silver;
0.05% by weight maximum lead;
0.05% by weight maximum antimony;
0.030% by weight maximum arsenic;
0.001% by weight maximum cadmium;
0.001% maximum zinc;
0.020% by weight maximum iron;
0.001% by weight maximum aluminum;
0.050% by weight maximum indium;
0.050% by weight maximum gold;
0.10% by weight maximum chromium; and
0.10% by weight maximum mercury.
3 . The solder alloy of claim 1 , further comprising 0.05% by weight maximum lead.
4 . The solder alloy of claim 1 , further comprising 0.05% by weight maximum antimony.
5 . The solder alloy of claim 1 , further comprising 0.030% by weight maximum arsenic.
6 . The solder alloy of claim 1 , further comprising 0.001% by weight maximum cadmium.
7 . The solder alloy of claim 1 , further comprising 0.001% maximum zinc.
8 . The solder alloy of claim 1 , further comprising 0.020% by weight maximum iron.
9 . The solder alloy of claim 1 , further comprising 0.001% by weight maximum aluminum.
10 . The solder alloy of claim 1 , further comprising 0.050% by weight maximum indium.
11 . The solder alloy of claim 1 , further comprising 0.050% by weight maximum gold.
12 . The solder alloy of claim 1 , further comprising 0.10% by weight maximum chromium.
13 . The solder alloy of claim 1 , further comprising 0.10% by weight maximum mercury.
14 . The solder alloy of claim 1 , further comprising 0.10% by weight maximum silver;
15 . The solder alloy of claim 1 , wherein the solder alloy is in the form of one of a bar, a stick, a solid or flux cored wire, a foil or strip, or a powder or paste, or solder spheres for use in ball grid arrays or chip scale packages, or other pre-formed solder pieces.
16 . The solder alloy of claim 1 , wherein copper is 0.600 to 0.800% by weight of the solder alloy.
17 . A solder joint formed by the solder alloy set forth in claim 1 .
18 . A method of forming a solder joint with the solder alloy set forth in claim 1 .
19 . A lead-free, silver-free solder alloy consisting of:
0.001 to 0.800% by weight copper;
0.001 to 0.050% by weight nickel;
0.001 to 0.012% by weight phosphorus;
0.001 to 0.008% by weight gallium; and
balance tin, together with unavoidable impurities.
20 . The solder alloy of claim 19 , wherein copper is 0.600 to 0.800% by weight of the solder alloy.