| 摘要 |
1,197,048. Semi-conductor devices. BROWN, BOVERI & CO. Ltd. 12 May, 1969 [16 May, 1968], No. 24132/69. Heading H1K. A semi-conductor device 4 is gripped firmly between two finned heat sink electrodes 1, 2 by three equispaced bolts 3 each insulated from the heat sinks by rings 11, 14 and a sleeve 16 and each provided with spring washers 9. During assembly, the structure is loosely bolted together and placed on the lower bed of an hydraulic press provided with three hexagonal studs each one of which fits into a corresponding recess in one of the bolt heads 6 to secure its bolt against rotation. The top plate of the press is universally jointed and is used to apply an even pressure to heat sink 1. The nuts 12 are then simultaneously tightened through bores in the top plate to bring two thrust washers 7, 10 on each bolt on to a spacer sleeve 8 around the spring washers. Each nut 12 is then loosened off by a predetermined amount (e.g. ¢ turn) so that the thrust is taken by the spring washers 9. (The length of individual spacer sleeves 8 is chosen to allow for production variations in the characteristics of the washer stacks). The completed unit is then removed from the press. In a variant, where even pressure on the device 4 is not so important, the spacer sleeves are omitted and the nuts 12 are simultaneously tightened to a predetermined torque while the assembly. is held in the press. |
