Method of Producing Semiconductor Devices

摘要

1,160,931. Welding by pressure. SYLVANIA ELECTRIC PRODUCTS Inc. 31 March, 1967 [1 April, 1966], No. 14925/67. Heading B3R. [Also in Division H1] Semi-conductor device wafers with leads extending beyond their peripheries, attached by one of the leads to a supporting grid to form an array are bonded to respective ones of an array of groups of conductive tracks on an insulating board by moving the board so that one group of conductive tracks is at a bonding station, moving the supporting grid so that one of the elements is at a transfer position, moving that element from the transfer position so that its leads are in register with the group of conductive tracks, and bonding them to the conductors. The process is repeated to attach each wafer to a group of conductive tracks. In one embodiment in which the grid and insulating board are mounted for independent two dimensional and rotational movement the board is moved so that each element in turn is brought into register with a group of conductors as shown in Fig. 6, beneath a welding tool. This then presses the leads 21-24 into contact with the conductive tracks 31-34 and forms ultrasonic welds between them. Lead 24 is then cut to detach the bonded element from the grid and another element and group of conductors brought into register and welded and so on. Alternatively lead 24 is provided with a weakened portion at which it breaks when the grid or board is moved to a new position. In another arrangement the grid and board remain spaced apart during the process, the grid being moved after each welding to position another element beneath a suction head by which it is transferred to the welding location after being severed from the grid. In all cases when all the elements have been attached the board is divided into strips, Fig. 10, and a pair of combs with spaced interleaved groups of teeth constituting terminal conductors welded to the conductive tracks on the strip. The strips are then cut between the elements to form two strings of headers which are encapsulated in plastic before the terminal conductors are separated from the combs. Diodes and integrated circuits may be attached to headers or printed circuit boards by similar methods to the transistors shown. Preferably the grid and leads are attached to the device wafers while they form part of the common wafer.