A Short History of Flip Chip and Wafer Level Packaging

摘要

Flip chip packaging was developed over 50 years ago by IBM to automate semiconductor assembly and improve reliability. It is important to remember that in the early 1960s, wire bonding was done with manual tools using thermocompression bonding, resulting in both increased cosls and reduced reliability. Al IBM, the first devices to use flip chip inierconnecls were transistors that were called, in IBM vernacular, Solid Logic Transistor (SLT) technology. The SLT devices had three terminals and used copper balls joined to the SLTs pads with solder. The SLT devices were joined to ceramic pin grid array substrates. The ability to produce packaged SLT devices with high reliability and in high volume was instrumental in the commercial success of the IBM 360, the first high-volume computer system, introduced in 1964.