Ni/Ni-Sn/Ni sandwiched simulated package structures weresuccessfully bonded under low temperature and low pressure byNi-Sn transient liquid-phase sintering bonding. The results showthat, after isothermally holding for 240 min at 300 °C and 180 minat 340 °C, Sn was completely transformed into Ni3Sn4 intermetalliccompounds. When the Ni3Sn4 phases around Ni particles werepressed together, the porosity of the bonding layer increased, whichobviously differed from the normal sintering densification process. With further analysis of this phenomenon, it was found that largevolume shrinkage (14.94% at 340 °C) occurred when Ni reactedwith Sn to form Ni3Sn4, which caused void formation. Amechanistic model of the microstructural evolution in the bondinglayer was proposed. Meanwhile, the resistivity of the bonding layerwas measured and analyzed by using the four-probe method; themicrostructural evolution was well reflected by the resistivity ofthe bonding layer. The relationship between the resistivity andmicrostructure was also discussed in detail.
Ni/Ni-Sn/Ni sandwiched simulated package structures weresuccessfully bonded under low temperature and low pressure byNi-Sn transient liquid-phase sintering bonding. The results showthat, after isothermally holding for 240 min at 300 °C and 180 minat 340 °C, Sn was completely transformed into Ni3Sn4 intermetalliccompounds. When the Ni3Sn4 phases around Ni particles werepressed together, the porosity of the bonding layer increased, whichobviously differed from the normal sintering densification process. With further analysis of this phenomenon, it was found that largevolume shrinkage (14.94% at 340 °C) occurred when Ni reactedwith Sn to form Ni3Sn4, which caused void formation. Amechanistic model of the microstructural evolution in the bondinglayer was proposed. Meanwhile, the resistivity of the bonding layerwas measured and analyzed by using the four-probe method; themicrostructural evolution was well reflected by the resistivity ofthe bonding layer. The relationship between the resistivity andmicrostructure was also discussed in detail.