Munich, Germany The continuous miniaturization of mobile applications and the resulting shrinking of module sizes requires ever smaller pitches. This miniaturization also presents a challenge to the socket manufacturers, as not only the reliability, but also the processing capability of the contact systems for Test & Burn-In applications must be ensured. Yamaichi Electronics used Compression Mount Technology (CMT) for its BGA/CSP 0.4 mm pitch socket from the NP437 series , as it can be realized without any great effort in comparison to Through Hole (TH) or Surface Mount Technology (SMT). The flexible buckling beam contacts are pressed onto the bond surfaces of the PCB, which is brought about by screwing the socket on the PCB. The ball bonds of the IC are also contacted by means of the buckling beam which is extremely space-saving due to it being vertically pressed on, and which also possesses excellent mechanical load qualities. Possible effects of the larger pin length on the electrical characteristics are negligible, as the semi-conductor device to be contacted operate in the "low current range" and the burn-in is carried out at "low frequency". Yamaichi Electronics , Munich, Germany. www.yamaichi.de.