Patents Assigned to GMN Georg Muller Nurnberg AG
  • Patent number: 5285597
    Abstract: A device for subdividing semiconductor bars into wafers comprises a grinding tool having two concentrically arranged grinding discs. A rough grinding disc is arranged inside of an outer smooth polishing grinding disc. The grinding tool grinds a lower face of a semiconductor bar to a smooth planar form. A first electrolytic truer operates in conjunction with the outer smooth polishing grinding disc while a second electrolytic truer operates in conjunction with the inner rough grinding disc. The truers are arranged to define an axial offset between the grinding surfaces of the grinding discs so that a lower face of the bar is smoothed. The device also has a slicing tool for slicing the bar into wafers which will have a smooth planar form.
    Type: Grant
    Filed: November 6, 1992
    Date of Patent: February 15, 1994
    Assignee: GMN Georg Muller Nurnberg AG
    Inventor: Hubert Hinzen
  • Patent number: 5161332
    Abstract: In a chucking apparatus for the combined grinding and honing working of a racetrack surface of a roller bearing external ring, a first chucking device comprising a pair of glide shoes and a second chucking device comprising a hydrostatic glide bearings wherein the first chucking device the grinding is integrated as a multiple arrangement into an indexable round table while the second chucking device is capable of being moved by simple axial shifting into the honing chucking device integrated into the round table.
    Type: Grant
    Filed: February 8, 1991
    Date of Patent: November 10, 1992
    Assignee: GMN Georg Muller Nurnberg AG
    Inventor: Peter Koch
  • Patent number: 4967725
    Abstract: Wafers are manufactured from an ingot of semiconductor material by first machining a front face of the ingot to provide a substantially planar reference surface and then slicing the ingot using looped cutting wire apparatus. The cutting wire apparatus includes a looped cutting wire and at least two drive rollers over sectors of which the cutting wire is wrapped. Each drive roller is provided with its own drive motor which has shunt motor characteristics. The speed and torque of each motor is adjustable relative to the load applied to its drive roller by the cutting wire such that all of the drive rollers participate in driving the cutting wire with substantially the same reliability against slippage so that wear is distributed uniformly over all of the drive rollers.
    Type: Grant
    Filed: February 16, 1989
    Date of Patent: November 6, 1990
    Assignee: GMN Georg Muller Nurnberg AG
    Inventor: Hubert Hinzen
  • Patent number: 4967461
    Abstract: Method and apparatus for manufacturing thin wafers from bars, such as in the manufacture of wafers for use as semiconductor substrates, include an arrangement wherein a holder member is fastened to the bar, the bar is sliced to separate a disc-shaped wafer therefrom and wherein prior to completion of the slicing operation, the end face of the bar is leveled to a precisely planar condition. The slicing operation is terminated after the bar is sliced completely through and the holder member is partially, but not completely, sliced through so that a wafer formed by the slicing operation remains connected to the bar by the holder member. The wafer is disconnected from the bar by abrading a portion of the holder member connecting the wafer to the bar.
    Type: Grant
    Filed: July 31, 1989
    Date of Patent: November 6, 1990
    Assignee: GMN Georg Muller Nurnberg AG
    Inventor: Fritz Feldmeier
  • Patent number: 4881518
    Abstract: Apparatus for manufacturing thin wafers from bars, such as in the manufacture of wafers for use as semiconductor substrates, include an arrangement wherein a holder member is fastened to the bar, the bar is sliced to separate a disc-shaped wafer therefrom and wherein prior to completion of the slicing operation, the end face of the bar is leveled to a precisely planar condition. The slicing operation is terminated after the bar is sliced completely through and the holder member is partially, but not completely, sliced through so that a wafer formed by the slicing operation remains connected to the bar by the holder member. The wafer is disconnected from the bar by abrading a portion of the holder member connecting the wafer to the bar.
    Type: Grant
    Filed: November 3, 1988
    Date of Patent: November 21, 1989
    Assignee: GMN Georg Muller Nurnberg AG
    Inventor: Fritz Feldmeier