What is claimed is:
1. A soldering compound, comprising
a lead-free solder alloy component selected from the group consisting of Sn--Ag--In; Sn--Ag--In--Bi; Sn--Ag--Bi; and Sn--Ag--Bi--Cu, the solder alloy component having
Sn in amount of about 86 to about 97%, Ag in an an amount of about 0.3 to about 4.5%, In in an amount of 0.00 to about 9.3, Bi in an amount of 0.00 to about 4.8%, and Cu in an amount of 0.00 to about 5% on a weight basis, and
the balance being an intermetallic filler selected from the group consisting of Cu.sub.3 Sn, Cu.sub.6 Sn.sub.5, Ni.sub.3 Sn.sub.2, Ni.sub.3 Sn.sub.4, Ni.sub.3 Sn.sub.7, AuSn, AuSn.sub.2, AuSn.sub.4, FeSn, FeSn.sub.2, and Ag.sub.3 Sn.
2. The compound of claim 1, wherein the solder alloy component comprises 87-89% Sn, 2.7-3.9% Ag, and 3.3-9.3% In.
3. The compound of claim 1, wherein the solder alloy component comprises 89-93% Sn, 2.4-3.6% Ag, 1.5-8.8% In, and 1.5-4.8% Bi.
4. The compound of claim 1, wherein the solder alloy component comprises 86-94% Sn, 0.3-0.7% Ag, 2.5-5 9.0% In, and 3.0-5.0% Cu.
5. The compound of claim 1, wherein the solder alloy component comprises 87-97% Sn, 2.5-4.5% Ag, and 1.0-4.8% Bi.
6. The compound of claim 1, wherein the solder alloy component comprises 90-94% Sn, 0.3-0.5% Ag, 2.0-3.0% Bi, and 3.0-5.0% Cu.
7. The compound of claim 1, wherein the intermetallic filler comprises 30% by volume of the solder compound.
8. The solder compound of claim 1 wherein said solder alloy component is in the form of a bulk solder.
9. The solder compound of claim 1 wherein said solder alloy component is in the form of a paste solder.