Abstract: A semiconductor wafer (40) is placed in a first pressure chamber (37) of a bonding apparatus (10 or 60). A major surface (46) of a submount (44) is placed on a submount support (30 or 62). The major surface (46) of the submount (44) seals the first pressure chamber (37). A pressure differential is generated between the first pressure chamber (37) and a second pressure chamber (47) The pressure differential bows a central portion of the submount (44) toward the semiconductor wafer (40). The central portion of the submount (44) contacts an adhesive coating over a central portion of the semiconductor wafer (40). The submount support (30 or 62) is displaced to decrease a curvature on the submount (44). The pressure differential is increased to an end-point to facilitate bond formation between the semiconductor wafer (40) and the submount (44).

Abstract: An apparatus (60) which handles fragile semiconductor wafers (21) adhesively mounted to a submount (22) using a high temperature wax is provided. The apparatus (60) includes a vacuum chuck (24) for holding a first surface of the wafer (21) and a solvent chamber (11, 11') for applying solvent to the back surface of the submount (22). The apparatus (60) includes an enclosure (29) for providing an inert gas environment around the solvent chamber (11, 11'), the wafer (21), and the vacuum chuck (24). The apparatus (60) further includes a means for remounting (30) the wafer (21) to a submount (22) using a low temperature wax after the high temperature wax is dissolved. The wafer (21) is then released from the vacuum chuck (24) and the first surface of the wafer (21) is mounted to an adhesive tape (34). Following the mounting, the low temperature wax is dissolved or melted to demount the wafer (21 ) from the submount (22), leaving the wafer (21) securely mounted on the adhesive tape (34) for sawing.

Abstract: A pump for handling abrasive materials includes a housing having two chambers. A shaft mounts a high pressure impeller and a high volume impeller in respective chambers of the housing, each chamber having a separate and opposite inlet. A channel is provided to divert a portion of the flow generated by the high pressure impeller to a purge ring adjacent the primary inlet corresponding to the high volume impeller. The purge ring directs a flow of relatively abrasive-free liquid toward the inlet to reduce wear on the housing and high-volume impeller. Another part of the flow from the high pressure impeller is diverted through the housing to isolate portions of the housing and the high volume impeller from the abrasive material laden intake through the primary inlet.

Abstract: A wax (13) dissolved in solvent is placed on a semiconductor wafer (12) and made uniform. An assembly is formed by bonding the semiconductor wafer (12) to a submount (17) with a uniform wax layer (14). The submount (17) supports and allows handling of the semiconductor wafer (12) during wafer process steps. The assembly is heated in a vacuum to remove solvent and air trapped in the uniform wax layer (14) thereby minimizing air voids which can cause a non-uniform bond. The assembly is then annealed to reduce stress on the semiconductor wafer (12) induced by differing material thermal expansion rates of the semiconductor wafer (12), the uniform wax layer (14), and the submount (17).

Abstract: An automatic drive chain tensioner having a pair of idler assemblies, with each idler assembly comprising an idler sprocket and an indexing sprocket on each side of, and concentrically connected to, the idler sprocket with each idler assembly being adapted to be positioned on the outside of a drive chain loop on a chain run between a drive and driven sprocket with the idler sprocket thereof adapted to be engaged in the drive chain and with the idler assemblies on different and opposite spaced-apart drive chain runs; and a pair of indexing chain loops, each one of which is adapted to engage an indexing sprocket on each of the spaced-apart idler assemblies on the same side of the drive chain. Desirably, the idler sprockets are the same size and, desirably, the indexing sprockets are the same size but not necessarily the same size as the idler sprockets.