Todays electronics industry faces complex production chains, a high lead density on the circuit boards and high demands on reliability. Thus the quality of the solder joints has become the central issue. The formation of brittle intermetallic compounds (IMCs) in a solder joint during soldering therefore needs to be precisely understood, and the corresponding basic information can be obtained from the phase diagram. To provide the scientific basis for the interactions between Sn-based solders and electroless Ni-Au surfaces, phase equilibria in the ternary Ni-P-Sn system are described in this...