A computer apparatus includes a hierarchy of solder joints in a multi-chip package, with solder joints at different levels of the packaging having different melting temperatures. Interconnections, such as pads or pins, on integrated circuit (IC) die can be electrically coupled to ends of contact pillars with solder joints having a higher melting temperature. The other ends of the contact pillars can electrically couple to another substrate or another device with solder joints having a lower melting temperature. The contact pillars can be, for example, a contact array or through-hole via in a substrate.