S-CAM 4.8 Onsemi Image Sensor Investigation Status

May 2024

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Capillary at K&S Wirebonding Machine
• Screw shown in picture holds capillary (white component)
in place at the arm of USG transducer in wirebonding
machine
• Capillary is replaced when lifetime reached
• Wirebonding machine tracks capillary replacement cycle
• Screw needs tightening with proper torque after every
capillary replacement
• Screw replacement cycle is for every 30 capillary
replacements
• Proper torque of screw is required for transferring
accurate level of USG energy for bond formation

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DOE Tweezer Pull Results After PKG & Timeline
• Remaining activities from DoE original plan
• All builds completed. Final analysis on crosssection and IMC coverage is ongoing
• Updated DoE Plan with additional testing
• Tweezer test added
• MSL3+3xIR+RT+HT completion mid-May
• 1000TC+RT+HT completion June-end
• Sample decap/WBS/SP testing in mid-June
• UHAST+RT+HT completion mid-June
• Sample decap/WBS/SP testing in mid-June

• Lifted wire-bond (pad peeling) duplicated in DoE packaged samples
• Failure mode similar to field failure units
• DoE timeline updated with additional stress testing added
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reproductions of this document may be made, and the contents of this document may not be disclosed to persons other than authorized personnel of the ZF Group and/or its subsidiaries, without the prior approval of ZF Group attorneys.

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Root Cause Of Wire Bonding Issue Investigation
• The supplier has narrowed down the root cause and
identified one of the wire bonders created most of the
failure parts.
❑ According to the production and maintenance records,
the capillary was replaced on the shift of F2332560,
however, for some reason the screw was loosen.
❑ After shear test there is an OOC (out of limit) sample
identified, the operator retorque the capillary screw to
fix the OOC event, however, he forgot to re-calibrate the
impedance right after the maintenance.
❑ This condition continued to run till end of the shift and
continued the next shift F2332563 without calibration.
Under this condition there are total 23 pcs failure been
produced.
❑ The capillary was replaced when the shift changed to
F2332568, and there is no failure occurred anymore.
• Conclusion of the root cause:
❑ Due to human error during the production OOC event,
no calibration after capillary retightened screw and this
caused impedance variation during wire bonding
operation.

Capillary

Screw

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No copies or other reproductions of this document may be made, and the contents of this document may not be disclosed to persons other than authorized personnel of the ZF Group and/or its subsidiaries, © ZF Friedrichshafen AG
without the prior approval of ZF Group attorneys.

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