| 摘要 |
1,225,042. Soldering. NORTH AMERICAN ROCKWELL CORP. 6 May, 1968 [4 May, 1967], No. 21405/68. Heading B3R. [Also in Division H1] The Figure shows part of an interconnection substrate for several micro-circuit chips. The substrate is provided with any necessary crossover connections (Fig. 3, schematic, not shown). Conductors 12 on the substrate are provided with raised bonding portions 20 which match with corresponding raised regions on the microcircuit chip to be attached. Bonding is effected by heating to form a eutectic from materials in the raised portions and regions. As shown, the raised portions 20 are low resistivity semiconductor 22 (germanium or silicon) bearing a coating 24 of a eutectic-forming metal. The raised regions on the chip (not shown) are similar-the metal may be the same or different. When the assembly is heated a eutectic is formed from the semi-conductor (of both the portions and the regions) and the or both metals. Useful metals to form a eutectic with silicon are gold, aluminium, silver, platinum, antimony, magnesium, copper, lead, and nickel. The atmosphere used may be, for example, air, when gold is used or argon, nitrogen, hydrogen, or forming gas when aluminium is used. The process may be modified by providing all the semiconductor to form the eutectic on either the chip or substrate and all the metal on the other. The substrate may be entirely of insulating material or may be of insulator-coated metal. The ridge 30 (having parts similar to those of the portions 20) matches a ridge on the chip, the two being bonded together to hermetically seal the face of the chip and the devices it contains. The ridge is separated from the conductors 12 by insulation 36. Several types of conductors which may be used are illustrated. Conductor 12b is metallic; conductors 12c each have a core 27 of relatively oxidizable metal protected by a tarnish-resistant metal layer 28; and conductor 12a are of low resistivity semi-conductor coated with a metallic layer 26 to decrease the overall resistance. |
