| 摘要 |
PURPOSE:To contrive the reduction in manufacturing cost by a method wherein the mutual wiring of logical circuits of the (i-1)-th layer and the i-th layer is made only as the input wiring from the i-th layer to the (i-1)-th layer, and the (i-1)-th layer is inspected by impressing a potential as required. CONSTITUTION:Logical circuits 1, 2, and 3 are laminated in the order of (i-1), (i), and (i+1). Nodes N1-N3 of the input signal from the layer 3 to the layer 2 are connected to the same pad 6. In this case, no input of all the logical circuits is open. When signals of high potential are impressed on the inspection pad 6 by connecting power sources and grounds for every layer, a gate NAD1 becomes equivalent to an inverter, and a three-input gate NAD2 equivalent to a two-input gate; besides, a gate NOR1 to which the output of IV1 has been connected becomes equivalent to the inverter. When a signal is given to each input pad 4, the output corresponding to the logic up to the i-layer 2 appears in the pad by its combination. If it is different from an expected logical value, it is judged as defective below the i-layer 2, and the manufacture of after (i+1)-layer is stopped. This construction enables the reduction in cost by shortening the time for manufacture and inspection. |
