Abstract: One embodiment of the present invention concerns an integrated circuit that includes bond pads and special contact pads or points. The bond pads are for interfacing the integrated circuit as a whole with an external circuit, and are to be bonded to a package or circuit board. The bond pads are disposed on the die in a predetermined alignment such as a peripheral, grid, or lead-on-center alignment. The special contact pads are used to provide external test patterns to internal circuits and/or to externally monitor results from testing the internal circuits. The special contact pads may be advantageously located on the integrated circuit with a high degree of positional freedom. For one embodiment, the special contact pads may be disposed on the die at a location that is not in the same alignment as the bond pads. The special contact pads may be smaller than the bond pads so as not to increase the die size due to the special contact pads.

Abstract: One embodiment of the present invention concerns a test assembly for testing product circuitry of a product die. In one embodiment, the test assembly includes at test die and an interconnection substrate for electrically coupling the test die to a host controller that communicates with the test die. The test die may be designed according to a design methodology that includes the step of concurrently designing test circuitry and a product circuitry in a unified design. The test circuitry can be designed to provide a high degree of fault coverage for the corresponding product circuitry generally without regard to the amount of silicon area that will be required by the test circuitry. The design methodology then partitions the unified design into the test die and the product die. The test die includes the test circuitry and the product die includes the product circuitry. The product and test die may then be fabricated on separate semiconductor wafers.

Abstract: A two-terminal fuse-antifuse structure comprises a horizontal B-fuse portion and a vertical A-fuse portion disposed between two metallization layers of an integrated circuit device. The two-terminal fuse-antifuse can be programmed with a relatively high current applied across the two terminals to blow the B-fuse, or with a high voltage applied across the two terminals to program the A-fuse. Such a device, connected between two circuit nodes, initially does not provide an electrical connection between the two circuit nodes. It may then be programmed with a relatively high voltage to blow the A-fuse, causing it to conduct between the two circuit nodes. Then, upon application of a relatively high current between the two circuit nodes, the B-fuse will blow, making the device permanently non-conductive.