Abstract: Specially selected particles 32 of an irregularly shaped material are almost completely melted in a heated crucible 22. Then while a small upper portion of the material 32 is still partially solid, additional but smaller particles 38 of a material are added thereon. Another method also starts with the specially selected particles 32 of a material which are completely melted in the heated crucible 22. Then the top surface of the liquid is partially frozen into a structural layer 36 to receive the addition of the smaller particles 38. Both techniques substantially prevent extremely hot liquid which is dangerously reactive from being scattered outside the crucible 22 when additional material 38 is added therein. Finally the entire contents of the crucible 22 are melted and a single-crystalline ingot 48 is grown from a melt 34.

Abstract: PLanar articles such as silicon wafers 40 are removably mounted onto a flat microcellular polyurethane surface layer 48 of a carrier 30 to permit an exposed surface 42 of each wafer 40 to be polished.To retain the wafers 40 against lateral polishing forces on the carrier 30 the surface of the layer 48 is treated with a dilute organic acid prior to mounting the wafers 40. The treatment involves contacting the surface of the layer 48 with the acid selected from the group consisting of citric, propionic, formic and acetic acids. The surface of the layer 48 is thoroughly wetted with the acid after which all excess acid is scraped from the surface. The wafers 40 are then manually placed upon the surface while it is still wet.

Abstract: In Czochralski crystal growing operations, particularly those involving growth of silicon crystals, projecting formations of silicon monoxide, which sometimes form on the surface of the melt-containing crucible just above the surface of the melt, are avoided by perturbing the formation conditions at the region of probable formation. Such perturbations may include increasing the temperature of the crucible at the region of probable formation. The increase in temperature may be provided by including an aperture in the housing which surrounds and supports the crucible to enable locally greater radiative heating of the crucible in the region of probable formation. Other expedients for locally increasing the temperature of the crucible include, without limitation, selective frosting and other techniques for locally changing the emissivity characteristics of the crucible and/or the surrounding material.

Abstract: A carrier tape (20) is provided for assembling components to make semiconductor devices. The tape (20) is made from soft, copper foil (21). Patterns (27) containing clusters (24) of inner leads (28) and (30) are accurately formed into tape (20) for bonding to chips (52).Tape (20) is indexed for bonding the free ends (36) of inner leads (28) and (30) to pads (54) of chip (52). Then tape (20) is indexed for bonding fixed ends (34) of leads (28) and (30) to stiff outer leads (86).Leads (28) and (30) in cluster (24) are deformed into a precise bell-like shape called a "bug" with chip (52) riding horizontally on top of the bell. Bugging develops flexural and tensile stresses and bonding causes thermal stresses in leads (28) and (30). Such stresses can shift or twist bug (51); warp the structural margin (26) and holes (22) of tape (20), and they can distort adjacent lead clusters (24) on tape (20).One or more stress relief sites (39) are provided in leads (28) and (30) to uniformly control such stresses.

Abstract: A strip 20 has a drive margin 36 and a latent image of a pattern in a light sensitive coating 73 of a pattern portion 22 thereon. To avoid disturbing the pattern, the strip 20 is gripped by the drive margin 36 using a set 43 of pinch-drive rollers which drive the strip without disturbing the latent image. The strip 20 is driven through pattern development, cleaning and etching solution spray chambers 64, 66 and 108, respectively. One or more adjustable shields 78 are used to vary the time interval during which the strip 20 is sprayed by these solutions. By adjusting one or more shields 78 to suit changes in solution condition the time intervals for proper developing, cleaning and etching are coordinated for a speed at which the strip 20 is driven.