Tail Breaking Force in Thermosonic Wire Bonding with Novel Bonding Wires

Abstract

Tail breaking forces (TBFs) are measured for various process conditions to understand phenomena such as short tail formation. TBFs obtained with several Cu wires are compared to find the most suitable Cu wire type that improves consistent tail formation. In situ online TBF measurement method is developed. The highest TBF obtained is 61.59 + 9.10mN. The highest Cpk value obtained is 2.97 + 0.33 when lower specification limit of 10 mN is assumed.

Online methods to measure breaking force of bonding wire using a CMOS stress sensor and a proximity sensor

“…For the compressive and the tensile cases, this relationship is given by (Eqs. (4) and (5)), respectively. Table 5 shows the average change in the values of f n for models C and T for the estimated variation in the values of various parameters.…”

“…The second method uses the proximity sensor mounted on the wire clamp of the bonding machine. Once calibrated, the proximity sensor method is used to measure and optimize the TBF process with novel wires [4,5].…”

Unconventional applications of wire bonding create opportunities for microsystem integration

“…The pulling force required for fracture is achieved by applying a wire clamp to the wire, preventing slippage relative to the capillary, and then retracting the capillary away from the substrate. Most studies done on determining the breaking force and resulting morphology are experimental [35][36][37]. However, Shah et al [37] presents a dedicated CMOS sensor for in situ online measurement of bond forces.…”