A fixed abrasive sawing wire with a rough interface between core and outer sheath

Abstract

A fixed abrasive sawing wire is presented that comprises a core (310) and an outer sheath layer (320) that is softer than the core. In the sheath abrasive particles are embedded that are held by a binding layer. The bond between core and sheath is enhanced by making it rough. The arithmetical mean deviating roughness must at least be higher than 0.50 micron. Particularly preferred is when interlocking between the core and the sheath is introduced. Such interface roughness can be obtained by subjecting the wire to sufficient cold forming by wire drawing. Interlocking will occur at even higher degrees of cold forming. The binding layer can be a metallic binding layer or an organic binding layer.

Description

technical field [0001] The present invention relates to a sawing wire, and more particularly to a monofilament sawing wire, on which abrasive grains are held in a metal sheath surrounding a metal core by a metal holding layer. The wire sheath is anchored to the core via an interface with roughness. This wire can be used to cut hard and brittle materials such as quartz (for example for quartz crystal oscillators or reticles), silicon (for example for integrated circuit chips or solar cells), gallium arsenide (for high frequency circuits) , silicon carbide or sapphire (eg for blue light emitting diode substrates), rare earth magnetic alloys (eg for recording heads) or even natural or man-made stones. Background technique [0002] Plain carbon steel sawing wires are widely used, for example, to cut silicon ingots into thin slices—called wafers—for use in semiconductor devices or photovoltaic cells. Although the wire used is referred to as a "saw wire," the abrasive particles ...

AI Technical Summary

Problems solved by technology

The sheath does not add to the overall strength of the thread, but does increase the thickness of the thread

Thicker wires lead to increased kerf loss

"kerf loss" is the loss of workpiece material during the sawing process and should be kept to a minimum as higher kerf loss results in a loss of useful material

[0018] On the other hand, the sheath must be thick enough so that the abrasive grains do not penetrate the core wire, because if they penetrate the core wire, the core wire will lose its strength due to the formation of cracks due to the pressed abrasive grains

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