Pyramid probes: used core inspection – Cascade Microtech Pyramid Probes User Manual
Page 5

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Pyramid Probes: Used Core Inspection• 5
3. Inspect the core using the 20x objective.
Inspection Area
Criteria
Tips
Do all tips appear uniform in size and shape?
On a used core, missing, tilted or crushed tips can be waived by Engineering if they are a redundant contact
like ground or power, or if they still have electrical continuity.
Is there any high current damage to the signal trace evident around the probe tip?
The pass/fail criteria is the test program.
Provide feedback to Engineering to check
program for current protection on this
signal.
Electrical Traces
Are any anomalies present that affect the electrical trace metal?
An anomaly is something different,
abnormal, peculiar or not easily classified.
Anomalies greater than 50% of an electrical
trace width are acceptable on used cores if
the core passes electrical test.
Anomalies affecting the ground grid are
acceptable.
Are there any cracks in the electrical traces?
Cracks greater than 50% are acceptable on used cores if the core passes electrical test.
Cracks affecting the ground grid are acceptable.
To troubleshoot an electrical open, inspect the trace:
• First, inspect the immediate areas of component connections.
• Inspect the probe tip.
• Inspect the entire length of the trace.
Surface Layer
Cracks
Cracks may be present in the surface layer of the polyimide.
• Cracks originating from the beam are
acceptable
• Cracks parallel to an electrical trace,
but not within 20 µm of the beam are
acceptable.
Anomaly examples
Cracks originating from beam
Cracks parallel to trace
Pyramid Probes: Used Core Inspection