Testable TAB Tape With Inner Guard Ring
Original Publication Date: 1988-Sep-01
Included in the Prior Art Database: 2005-Feb-15
Present tape automated bonding (TAB) designs cannot be tested for electrical opens prior to chip bond, and can only be tested for electrical shorts by eliminating electrostatic discharge (ESD) protection. In addition, the TAB inner leads are unsupported, increasing chances of handling damage during manufacture. The following design is partly testable, without sacrificing ESD protection, and provides mechanical support to the inner bond leads. Any areas not testable could be visually inspected. One possible design is shown in the illustration. An Inner Guard Ring (IGR) 1 is used as an inner support area in the chip area. The IGR is a polyimide square which provides support for the inner leads which will be thermo-compression bonded to the chip pads.