Abstract: A method for thermocompression bonding structures together including structures having different coefficients of thermal expansion, for example, thermocompression bonding optical diode arrays or other semiconductor structures to silicon substrates to form electronic or optoelectronic devices. The method includes aligning and contacting the structures to be interconnected, thermocompressing the structures via their contact pad elements at a bonding temperature, establishing an encapsulation temperature, applying an encapsulant material between the bonded structures, and curing the encapsulant material at the encapsulation temperature. Conventional bonding processes, which treat encapsulation as a separate step apart from bonding processes, melt the bonded assembly together and include at least one thermal cycle in which the bonded assembly is cooled to room temperature and then is re-heated to the encapsulation temperature before applying the encapsulant material.

Abstract: Solder bonding of first and second contact pad arrays is accomplished by forming contact structures, such as posts with vertical or tapered sides, on the contact pads of the first array and solder bumps on the second array. The respective contact structures should have an average cross-sectional area that is less than the average cross-sectional area of the corresponding solder bumps. The contact structures and solder bumps are then bonded by a bonding process at a temperature and pressure where the solder bumps deform and envelop at least a portion of the respective contact structures. It is possible to employ the contact structures as a compression stop during the bonding process. The temperature should be below the melting points of the contact structures. In this manner, solder bump spreading can be reduced during bonding which correspondingly reduces electrical shorting of adjacent formed interconnect bonds.