| 摘要 |
It is an object of the present invention to provide a ceramic substrate with a Pb-free solder layer which has a melting point and bond strength equivalent to those of a Sn-Pb eutectic solder containing Pb that is considered to have a fear of environmental problems. The substrate for device bonding of the invention comprises a substrate having an electrode layer and a solder layer formed on the electrode layer, wherein the solder layer is a Pb-free solder layer which comprises (1) a base metal composed of (i) Sn, (ii) Sn and Au, or (iii) In, (2) at least one metal selected from the group consisting of Bi, In (only in the case where the base metal is Sn, or Sn and Au), Zn, Au (only in the case where the base metal is In) and Sb, and (3) at least one metal selected from the group consisting of Ag, Ni, Fe, Al, Cu and Pt, and the solder layer has a thickness of 1 to 15 µm and a surface roughness (Ra) of not more than 0.11 µm. |
