Method and apparatus for spatially uniform electropolishing and electrolytic etching

Patent · Wed Jan 01 00:00:00 EST 1992

OSTI ID:868190

Mayer, Steven T ^[1]; Contolini, Robert J ^[2]; Bernhardt, Anthony F ^[3]

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1. Piedmont, CA
2. Pleasanton, CA
3. Berkeley, CA

In an electropolishing or electrolytic etching apparatus the anode is separated from the cathode to prevent bubble transport to the anode and to produce a uniform current distribution at the anode by means of a solid nonconducting anode-cathode barrier. The anode extends into the top of the barrier and the cathode is outside the barrier. A virtual cathode hole formed in the bottom of the barrier below the level of the cathode permits current flow while preventing bubble transport. The anode is rotatable and oriented horizontally facing down. An extended anode is formed by mounting the workpiece in a holder which extends the electropolishing or etching area beyond the edge of the workpiece to reduce edge effects at the workpiece. A reference electrode controls cell voltage. Endpoint detection and current shut-off stop polishing. Spatially uniform polishing or etching can be rapidly performed.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
• DOE Contract Number: W-7405-ENG-48
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 5096550
• OSTI ID: 868190
• Country of Publication: United States
• Language: English

Related Subjects

method
apparatus
spatially
uniform
electropolishing
electrolytic
etching
anode
separated
cathode
prevent
bubble
transport
produce
current
distribution
means
solid
nonconducting
anode-cathode
barrier
extends
top
outside
virtual
formed
bottom
below
level
permits
flow
preventing
rotatable
oriented
horizontally
facing
extended
mounting
workpiece
holder
edge
reduce
effects
reference
electrode
controls
cell
voltage
endpoint
detection
shut-off
stop
polishing
rapidly
performed
cell voltage
reference electrode
current flow
virtual cathode
edge effects
form cu
current distribution
electrolytic etching
uniform current
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