Experimental study on improving μ- WEDM and μ-EDM of doped silicon by temporary metallic coating
Wire electro-discharges machining (WEDM) is a variant of electro-discharge machining (EDM) based method for non-contact machining that uses wire as the machining tool. Micro-EDMing/micro-WEDMing (where discharge energy is very low and tool size in micrometer range) operation of silicon (Si) can...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English English |
| Published: |
Springer
2015
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| Subjects: | |
| Online Access: | http://irep.iium.edu.my/43003/ http://irep.iium.edu.my/43003/ http://irep.iium.edu.my/43003/ http://irep.iium.edu.my/43003/1/IJAMT_published_printed.pdf http://irep.iium.edu.my/43003/2/Proof_ISI.pdf |
| Summary: | Wire electro-discharges machining (WEDM) is a
variant of electro-discharge machining (EDM) based method
for non-contact machining that uses wire as the machining tool.
Micro-EDMing/micro-WEDMing (where discharge energy is
very low and tool size in micrometer range) operation of silicon
(Si) can achieve features with very complex shapes, which have
many useful applications in microelectro-mechanical system
(MEMS). However, Si is a semiconductor material with high
resistivity, and it is difficult to create electrical sparks during μ-
WEDM/μ-EDM process. Thus, the machining of Si can be
enhanced if it is possible to increase the conductivity of this
semiconductor. This study aims to develop and characterize the
process of improved μ-WEDM and μ-EDM of Si by temporarily
coating Si with a high conductive metal (gold in this
study). Micro-WEDM process stability was found to be improved
(~100× for different machining condition) if coated Si
wafer is used as compared to uncoated Si workpiece. Material
removal rate (MRR) was also found to be increased by a good
margin (~30 % average) for coated Si wafer. Machined slots
were found to be more uniform though kerf width was slightly
larger for coated Si wafer. In case of μ-EDM operation, goldcoated
Si also enhanced the machining as compared to uncoated
Si. In this case, MRR was increased by up to seven times for
coated samples. Overall, this new method of μ-WEDM and μ-
EDM technique of polished Si wafer has been found to be more
efficient and useful. Removal of the conductive coating without
damaging the substrate is a challenge for this process, which
was carried out successfully by selective etching method. |
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