Patent ID: 7626273
Filing Date: 2009-12-01
Classification: H01L,H05K

Abstract:
1. A method of devising a stacked circuit module, comprising: disposing a first integrated circuit beneath a second integrated circuit; connecting the first and second integrated circuits using a flex circuit; and joining each of the first integrated circuit and the second integrated circuit to the flex circuit through a high temperature joint comprising an alloy, the alloy having a proportion of no more than 95% tin and at least 5% antimony, and having a melting point between 235° C. to 260° C., wherein the flex circuit comprises first and second outer layers, first and second conductive layers, between which there is an intermediate layer, the first and second conductive layers and the intermediate layer being interior to the first and second outer layers, the second conductive layer having demarked first and second flex contacts, the first flex contacts being accessible through first windows through the second outer layer and the second flex contacts being accessible through second windows through the first outer layer, the first conductive layer, and the intermediate layer.