| 摘要 |
<p>1484177 Mounting semi-conductor devices RAYCHEM CORP 3 Dec 1974 [3 Dec 1973 30 April 1974] 52318/74 Heading H1K An electrical component 6, e.g. a semi-conductor chip, is sealed on a substrate 2 having a wall or walls 12 surrounding the component, by inserting into the area defined by the wall(s) 12 and over the component 6 a heat-recoverable sealing member 14 which initially is of such a size and configuration as to fit loosely within the wall(s) 12, but which is subsequently warmed or allowed to warm so that it recovers to a second, stable state having an increased size and configuration which forms a seal with the walls. The heat-recoverable sealing member 14 may be made from a so-called "memory alloy", e.g. a nickel titanium alloy containing 47À1% Ni, 49À4% Ti and 3À5% Fe, a beta-brass alloy or a 304 stainless steel. A planar disc of such material is immersed in liquid nitrogen, at - 196‹ C., and deformed into a concave configuration of dimensions just smaller than the correspondingly shaped wall(s) 12 of the substrate and is placed over the component to rest on a lip formed in the wall(s). Upon warming, e.g. to a transition temperature in the range - 196‹ to +135‹ C., the sealing member will attempt to recover its original configuration and in so doing exert a force on the substrate walls sufficient to seal the component. Alternatively the sealing member 14 may be made of a heat-recoverable plastics, e.g. a polyarylene, which may recover to an original configuration upon heating up to or below 300‹ F. One of the members forming the seal, i.e. the sealing member 14, the substrate wall(s) 12 or an interposed ring 18, Fig. 3, is preferably formed of softer material than the other members to enhance the sealing. The ring 18 which may be bonded to the substrate, is preferably of V configuration. The sealing member may have a projection 16 to assist in locating it in the substrate or in removing it therefrom to enable access to be had to the semi-conductor component.</p> |
