Wire Electric Discharge Machining (WEDM) is a non-conventional machining technique, where the machining takes place due to heat produced by sparks between the wire and the workpiece. WEDM can be used for slicing semiconductor ingots to get semiconductor wafers. It is more efficient than the presently used multi-wire saw method, because it can reduce material losses from 40% to 15%. In addition, it can produce thinner wafers with lesser surface roughness. Apart from cutting semiconductor ingots, WEDM is also useful for cutting thin metallic plates required for applications like sputtering targets, cutting rare earth magnetic materials, and so on.
WEDM usually employs a single wire as the tool electrode. However, the advantages of WEDM can be leveraged only with a multi-wire EDM (MWEDM) as a single-wire EDM cannot compete with the high throughput (6500-15000 wafers per day) of multi-wire sawing. The currently developed MWEDM machines are not yet deployed for production as there are several challenges like wire vibrations, unavailability of dedicated pulse generator topologies, complex mechanical arrangement of wires, and so on.
This innovation uses an electrical supply scheme for a MWED machine that can minimize deflections and vibrations of the wires in the MWEDM. The associated pulse generator topology is also proposed.
Wire Electric Discharge Machining (WEDM) is a non-conventional machining technique, which can be an efficient alternative for cutting semiconductor wafers. WEDM is efficient in terms of surface roughness and material loss. It experiences lesser kerf losses - 15-20% against 40% in wire sawing techniques. It can produce ultra-thin wafers (≈ 100 µm) can be cut with WEDM.
However, it cannot compete with high throughput of multi-wire saw, which is the present technology for wafer production. Making a multi-wire EDM (MWEDM) is difficult due to several mechanical and electrical constraints to put multiple wires close to each other. One of the issues is the vibration of wires due to electrical forces between the wires.
- This technology can give an edge over the currently used multi-wire saw technology, which is the present workhorse of semiconductor wafer manufacturing.
- WEDM results in lesser kerf losses (15-20%) against 40% in wire sawing techniques.
- Ultra-thin wafers (≈ 100 µm) can be cut with WEDM.
- WEDM does not face problems of large cracks which occur when wire saw is used for slicing hard semiconductor materials like Silicon Carbide (SiC).
- The proposed electrical supply scheme, included within, minimises the deflections and vibrations in the MWEDM connected to the power supply.
- As it is an electrical supply scheme, and not a mechanical solution, it does not suffer wear and tear, and the electrical schemes can be adapted to any number of wires.
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The innovation has the potential to reduce the price of semiconductor wafers. The reduced material losses will permit manufacture of more wafers from the same amount of material.
Deploying MWEDM technology can make cutting silicon wafer ingots significantly more economical for the manufacturing industry.
Apart from cutting semiconductor ingots, there could be other applications of MWEDM as well, for example, cutting thin metallic plates required for applications like sputtering targets, cutting rare-earth magnetic materials, and so on.
Geography of IP
Type of IP
202021041051
492843