Cascade Microtech Pyramid Probes - Manual (Page 5)

PN 153-690-3 www.cascademicrotech.com Pyramid Probes: New Core Inspection • 5
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.
Middle Layer
Polyimide
Are there any cracks in the Middle Layer Polyimide that do not come to the surface?
This type of crack is acceptable unless it is
causing other damage to the membrane,
such as separation between the layers or
cracks through the entire membrane.
Stress Cracks
Are there any cracks in the surface layer of the membrane where it bends at the edge of the
face?
These cracks are not in the metal. They
are in the polyimide.
Change the focus of the microscope to
confirm the cracks are in the polyimide.
If cracks also appear in the electrical
traces, refer to the appropriate criteria in
Electrical Traces on page 4.
Cracks originating from beam Cracks parallel to trace
Acceptable Not acceptable. Membrane is
cracked and has some separation.
Pyramid Probes: New Core Inspection