What is Beam Lead
Beam lead is a technology used in the fabrication of semiconductor devices, particularly integrated circuits. It involves the direct deposition of a metal beam onto the surface of a semiconductor die during the wafer processing cycle. This beam extends from the edge of the chip and can be bonded directly to interconnecting pads on the circuit substrate, eliminating the need for individual wire interconnections. This method, known as flip-chip bonding, offers a more efficient and automated assembly process for semiconductor chips onto larger substrates.
The development of beam lead technology can be attributed to M.P. Lepselter in the early 1960s. Lepselter pioneered the fabrication techniques for creating self-supporting gold patterns, known as “beams,” on a thin film Ti-Pt Au base. These beams not only serve as electrical leads but also provide structural support for the devices. By removing the excess semiconductor material beneath the beams, individual devices are separated, leaving them with self-supporting beam leads or internal chiplets that extend beyond the semiconductor material.
Beam lead technology has gained recognition for its reliability in high-frequency silicon switching transistors and ultra-high-speed integrated circuits used in telecommunications and missile systems. It has also found applications in the production of Schottky diodes and contacts, as well as processes like plasma etching and precision electro-forming.