Wacker-Chemitronic Gesellschaft Fur Elektronik-Grundstoffe Mbh

Wacker Siltronic Gesellschaft Fur Halbleitermaterialien Ag

Wacker Chemitronic

Walter Frank

Albert Pemwieser

Maximilian Kaeser

Gerhard Spatzier

Vernon Knepprath

Gerhard Palme

A sawing suspension composition is composed of an essentially nonaqueous or anhydrous organic liquid in which hard-material particles are dispersed. The liquid is selected from a group of compounds which comprises low molecular weight polyglycols and any desired mixture of these polyglycols. The sawing suspension is used in conjunction with a wire saw for cutting wafers from a crystal of a brittle and hard material.

Method for cutting wafers from a crystal

The separation of thin disk-type workpieces from a stack has, as a rule, hitherto been carried out by hand. An apparatus and a corresponding method are now provided which make it possible to lift the wafer off the stack without mechanical contact, and also to convey the separated wafers to the tray and to introduce them in an automated way without damage. In this method, a stack of disk-type workpieces is introduced into a wafer magazine with a feed unit which brings the uppermost wafer of the wafer stack into the sphere of action of a fluid medium which emerges under pressure in a preferred direction from a nozzle system. A dam makes it possible to remove a single wafer. The apparatus and the method make possible separation without damage while increasing the yield. In conjunction with a conveying apparatus, an apparatus for tray filling processing lines can be built up for automatically treating disk-type workpieces without damage.

Apparatus and method of automatically separating stacked wafers

A method to be used for adjusting the radial deviation from the true runn position of the internal cutting edge of annular saw blades and an apparatus for carrying out the method. For this purpose, the radial deviation or out-of-true is first measured as a function of position. Subsequently, the saw blade is stretched as a function of position in a defined manner in order to compensate for the deviations from the specified value of the radial out-of-true as a function of position. The measuring and tensioning cycles are continued until the deviation from the specified value no longer exceeds a predetermined tolerance limit. Saw blades adjusted in this manner are characterized by long service lives and high cutting accuracy.

Method and apparatus for adjusting the true running of the cutting edge

A multi-blade inner hole saw for the sawing of crystal rods or blocks, such as solar cell base material on a silicon base, into thin wafers has saw blades arranged mirror-symmetrically with respect to the bearing on either side of a common drive cylinder. In the sawing operation, the workpieces are sawn synchronously by the saw blades.

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Burgkirchen, Germany

Walter Frank