Motorola Corporation

Lawrence R Gardner

Michael P Norman

Paul D Asetta

Rajiv Bajaj

James J Wang

Robert W Griffith, Jr

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).

Method for mounting a wafer to a submount

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.

Apparatus and method for handling fragile semiconductor wafers

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).

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Chandler, AZ, United States of America

Lawrence R Gardner