Tape-Automated Bonding
Encyclopedia
Tape-automated bonding (TAB) is a process that places bare integrated circuit
s onto a printed circuit board
(PCB) by attaching them to a polyamide
or polyimide
film.
The mounting is done such that the bonding sites of the die, usually in the form of bumps or balls made of gold or solder, are connected to fine conductors on the tape, which provide the means of connecting the die to the package or directly to external circuits. Sometimes the tape on which the die is bonded already contains the actual application circuit of the die.
The film is moved to the target location, and the leads are cut and soldered as necessary. The bare chip may then be encapsulated ("glob topped") with epoxy or plastic.
Standard sizes for polyimide tapes include widths of 35 mm, 45 mm, and 70 mm and thicknesses between 50 to 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.
Historically, TAB was created as an alternative to wire bonding
and finds common use by manufacturers in LCD display driver circuits.
Integrated circuit
An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...
s onto a printed circuit board
Printed circuit board
A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board or etched wiring...
(PCB) by attaching them to a polyamide
Polyamide
A polyamide is a polymer containing monomers of amides joined by peptide bonds. They can occur both naturally and artificially, examples being proteins, such as wool and silk, and can be made artificially through step-growth polymerization or solid-phase synthesis, examples being nylons, aramids,...
or polyimide
Polyimide
Polyimide is a polymer of imide monomers. The structure of imide is as shown. Polyimides have been in mass production since 1955...
film.
The mounting is done such that the bonding sites of the die, usually in the form of bumps or balls made of gold or solder, are connected to fine conductors on the tape, which provide the means of connecting the die to the package or directly to external circuits. Sometimes the tape on which the die is bonded already contains the actual application circuit of the die.
The film is moved to the target location, and the leads are cut and soldered as necessary. The bare chip may then be encapsulated ("glob topped") with epoxy or plastic.
Standard sizes for polyimide tapes include widths of 35 mm, 45 mm, and 70 mm and thicknesses between 50 to 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.
Historically, TAB was created as an alternative to wire bonding
Wire bonding
Wire bonding is the primary method of making interconnections between an integrated circuit and a printed circuit board during semiconductor device fabrication. Although less common, wire bonding can be used to connect an IC to other electronics or to connect from one PCB to another...
and finds common use by manufacturers in LCD display driver circuits.