| 摘要 |
1,237,672. Soldering. CORNING GLASS WORKS. 6 Nov., 1969 [15 Nov., 1968], No. 54413/69. Heading B3R. A method for forming a bond between a crystal 10 and a solid delay medium 18 comprises the steps of depositing metallic base layers 12, 14, 20 on the surfaces to be joined and then depositing on at least one of the layers a further layer of indium in a non-oxidizing environment, pressing the surfaces together at a pressure of at least 90 p.s.i., heating the indium to at least its melting point for at least 15 seconds and reducing the temperature below said melting point while under pressure so that indium solidifies to form said bond. The crystal 10 is a piezoelectric material and may be ceramic or quartz. The layer 12 is preferably a nickelchromium alloy or a layer of chromium followed by a layer of nickel can be substituted for the alloy after which a layer 14 of gold is deposited. These layers 12, 14 are deposited in a non- oxidizing environment such as an inert gas or vacuum. The delay medium 18 may be silica, glass or glass ceramic on which is deposited a nickel-chromium base layer 20 followed by a layer 22 of indium. The layers 12, 14, 20, 22 may be deposited by vacuum deposition, sputtering, vacuum evaporation or electron beam evaporation. Prior to mating it may be desirable to burnish the surface of the indium layer 22 with a nylon cloth to remove any oxides and surface impurities. The indium layer may be applied to either or both of the base layers. Alternatively the base layers may comprise successive coatings of aluminium, nickel and gold or may just be platinum or an alloy of gold and platinum. |
