Cascade Microtech Pyramid Probes - Manual (Page 6)

PN 153-691-2 www.cascademicrotech.comI Pyramid Probes: Used Core Inspection• 6
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 5.
Membrane
Surface
Were any particles created or formed below the membrane (poly2) surface during the
thinfilm fabrication process?
Internal encapsulated particles are acceptable as long as they pass all other specifications.
Polyimide may appear rough and discolored around the beams, component attachment pads, or any other
plated metal area forming part of the membrane surface:
• On the probe face, this is acceptable up to 200µm radius around the beams or other plated metal area
forming part of the membrane surface.
• On the wings and the interface area, this is acceptable in all areas.
Acceptable Not acceptable. Membrane is
cracked and has some separation.
Acceptable
Cross section with internal
encapsulated particle
Acceptable
Pyramid Probes: Used Core Inspection