| 摘要 |
PURPOSE:To facilitate the operation of a test by selectively fitting semiconductor switches among pads around a semiconductor chip and among the pads and an internal circuit, transmitting a signal through a select bus and switching connection among the pads and the internal circuit. CONSTITUTION:Switch elements 5a-5g are set up among the pads 2a-2g and the internal circuits A-F in a predetermined manner, 5a, 5c, 5e are formed in N channels and 5b, 5d, 5f in P channels, and the pad 2g is connected to a select bus 6. The bus 6 is connected to each input to the elements 5a-5f. When a 'H' signal is transmitted over the pad 2g from a terminal T4 for the test, the elements 5a, 5c, 5e are turned OFF and others ON, and the circuits B, D, E can be inspected. When a 'L' signal is transmitted from the terminal T4, ON-OFF is reversed, and the circuits A, C, E can be inspected. According to the constitution, terminals T may be n+1 pieces on 2n pads, the IC of a large number of pins can be tested by a tester of a small number of terminals, and a test board is easily manufactured. |
