| 摘要 |
<p>1440196 Soldering LICENTIA PATENTVERWALTUNGS GmbH 6 June 1973 [13 June 1972] 27064/73 Heading B3R A method of producing a solder layer of predetermined thickness in the production of soldered semi-conductor components comprises incorporating in the solder particles of additional material which are substantially unaffected in size by the soldering operation and which are dimensioned to space the parts 1, 2 to be joined by the required solder thickness. The additional material generally forms less than about 12% by weight of the solder. Incorporation of the additional particles in the solder may be effected by mixing the particles into molten solder, rolling the particles into a foil of solder, mixing in pulverized state followed by fusing or sintering. The particles are preferably spherical or cylindrical and the outer surface thereof is such that while capable of being wetted by the solder it is substantially insoluble therein. The self spacing solder may be applied to the joint surfaces by dipping, roll plating, pressing, melting of solder foil, or placing of moulded/stamped preforms, e.g. rings or discs. Specific solders referred to include: 90% Pb 5% In 5% Ag; 60% Pb 40% Sn; 90% Pb 10% Sn; 97% Pb 3% Sn; 80% Au 20% Sn and hard solders. Specific materials of which the particles may be formed and which are referred to include: copper, silver, silver/gold alloys (e.g. 90% Ag 10% Au), tungsten and molybden or particles of these materials coated with nickel, nickel, glass, ceramics or metallized glass or ceramics.</p> |
