LAYERED SOLDER MATERIAL FOR BONDING DISSIMILAR ELECTRODES, AND METHOD FOR BONDING DISSIMILAR ELECTRODES TO ELECTRONIC COMPONENTS

摘要

When soldering a package having an electrode on which Ni/Au or Ag-Pd alloy is plated to a printed circuit board having a Cu electrode or an electrode on which Cu is plated, a solid-phase diffusion layer is formed within the inside of a layered solder material for bonding different species of electrodes by heating and cooling the layered solder material for bonding different species of electrodes. The layered solder material is composed of a solder material of Sn-Ag-Cu series or Sn-Sb series and a solder material of Sn-Ag-Cu-Ni series or Sn-Pb series. The electrode on which Ni/Au or Ag-Pd alloy is plated and the Cu electrode or the electrode on which Cu is plated are soldered with the solder material of Sn-Ag-Cu series or Sn-Sb series being attached to the Cu electrode and the solder material of Sn-Ag-Cu-Ni series or Sn-Cu series being attached to the electrode on which Ni/Au or Ag-Pd alloy is plated. This allows formation of intermetallic compounds to be restrained, thereby soldering them with high bonding reliability.