Multi-spherical probe machining by EDM
Combining WEDG technology with one-pulse
electro-discharge
Name: Chin-Yao Lai
M9510242
Adviser: C-H Chuang
Abstract
This paper describes a hybrid technique combining wire electrodischarge grinding (WEDG) technology with one-pulse
electrodischarge (OPED), to fabricate multi-micro-spherical probes.
The results show that a burnished micro-spherical probe with
diameter of about 40m could be formed instantaneously, which is
not available with conventional machining methods。
Machining Procedure
The fabrication procedure of a 30 um diameter electrode by WEDG
The electrode material is a 300um diameter rod of tungsten, which
is available in commercial market
Procedure of OPED system
Experimental results and discussion
In comparison to the EDM,OPED system can obtain a
spherical probe with excellent smooth surface
Surface roughness of the probe
with OPED system
Surface roughness of the probe
with Micro-EDM
Duration of the OPED system
The experimental results of the relations of the
duration and the diameter of the spherical probe
Relations of diameter and duration
Repeatedly machining of OPED system
Different cross-section of the
microelectrode
WEDG technology is available to fabricate some kinds of crosssection shape of the microelectrodes. Electro-discharge occurred
to one of the probes but not to all of the probes simultaneously
The procedures of multi-micro-spherical probes fabrication
multi-micro-spherical probes
probe with tungsten carbide
Summary
Compared to the micro-EDM crater, the roughness of the surface of the
micro-spherical probe is very smooth. It is expected that a high accuracy
of measurement can be achieved by attaching the micro-spherical probe
on a CMM。
The experimental results show that multi-microspherical probes can be
fabricated, which conventional method is not available. It is also possible
to achieve mass production of the spherical probe with combining wireEDM in the future。
The smallest obtainable electrode diameter was approximately 10um in
this study. Using an electrode of this diameter, a 15um diameter spherical
probe was fabricated successfully。