Assembly and packaging of semiconductor chip - where elastomer ring clamps chip onto counter-electrode so both are free to expand and contract independently

摘要

A silicon transistor chip (I) with a chamfered edge is located without alloying on a counter-electrode (II) with a larger dia. than chip (I). Electrode (II) is made of a metal with a coefft. of thermal expansion similar to that of Si, e.g. Mo, W or Ta. The chip (I) is held on the electrode (II) by a ring moulding made of a flexible polymer and provided with inner top and bottom ring flanges projecting over the rims of both components. A very thin Ag disc is pref. located between the chip and electrode (II); and a second Ag disc is prf. placed on top of the chip (I) below a second counter-electrode which is pressed against the chip. The assembly is then placed in a box. The ring moulding is pref. made from a silicone polymer. Used esp. in the packaging of power semiconductors so the chips are not cracked or damaged.