Tape-automated bonding

Places a microchip on a flexible circuit board

Tape automated bonding (TAB) is a process that places bare semiconductor chips (dies) like integrated circuits onto a flexible circuit board (FPC) by attaching them to fine conductors in a polyamide or polyimide (like trade names Kapton or UPILEX) film carrier. This FPC with the die(s) (TAB inner lead bonding, ILB) can be mounted on the system or module board or assembled inside a package (TAB outer lead bonding, OLB). Typically the FPC includes from one to three conductive layers and all inputs and outputs of the semiconductor die are connected simultaneously during the TAB bonding. Tape automated bonding is one of the methods needed for achieving chip on flex (COF) assembly and it is one of the first roll to roll processing (also called R2R, reel to reel) type methods in the electronics manufacturing.

Standard sizes for polyimide tapes include widths of 35 mm, 45 mm, and 70 mm and thicknesses between 50 and 100 micrometers. Since the tape is in the form of a roll, the length of the circuit is measured in terms of sprocket pitches, with each sprocket pitch measuring about 4.75 mm. Thus, a circuit size of 16 pitches is about 76 mm long.

Technically the process was invented by Frances Hugle patent issued 1969 although it was not named as TAB. The TAB was first outlined by Gerard Dehaine 1971 at Honeywell Bull. Historically, TAB was created as an alternative to wire bonding and finds common use by electronics manufacturers. However speed up of wire bonding methods and development of flip chip enabling simultaneous bonding of all IOs of the die and easier repaire compared to TAB have pushed TAB bonding to be used in specific areas like for interconnection of display drivers to the display like liquid crystal display (LCD).