Verification
Clean you can measure.
A clean surface is a measured result. These are the methods used to qualify plasma cleaning before wire bonding and molding — with example data from Awing's qualification work.
Four methods
Each one against a spec.
Water contact angle
A water drop on the treated surface: the lower the angle, the better it wets. Qualification spec below 30°.
Ball shear
The force needed to shear the ball bond off the pad, checked against a lower spec limit of 40 g.
Stitch pull
The force needed to pull the wire at the stitch bond, checked against a lower spec limit of 10 g.
Cu residue after shear
The share of the pad still covered by copper after the ball is sheared off. Spec above 75%.
Clean, in numbers.
Every process is qualified with the same measurements, each against a specification the surface has to pass.
Water contact angle
spec < 30°
Qualification lots — mean of four drops
Ball shear
> 40 gmin–max per groupmean
Stitch pull
> 10 gmin–max per groupmean
Cu residue after shear
> 75%95–100% on every group
Example qualification data · Awing product brochure, Jan 2026 · Results depend on substrate, contamination and process settings
Reports and follow-up.
- — Residue check
- — Substrate inspection
- — Acceptance criteria
Need data for your application?
Ask for qualification data or a test report — sent by email on request.
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