First Bond Ball/Stud Bump Pull
Copper is increasingly replacing gold as the interconnect material for wire bonds, stud bumps and pillars which provides several advantages including cost reduction, superior electrical and thermal conductivity and less intermetallic growths.
Testing the mechanical integrity of these bonds is an important aspect of the manufacturing quality assurance process however testing copper interconnects presents several challenges for traditional shear testing. To overcome these Nordson DAGE has introduced the first bond ball pull (FBBP) test method; the ball bond is gripped using a specialised tweezer jaw in such a way that a vertical load is applied to the bond thus enabling a pull test to be applied.
First bond ball pull testing is predominantly used as an alternative to ball shear testing to verify copper wire ball bonds which is increasingly being as an alternative to gold for semiconductor interconnects. First bond ball pull utilises cold bump pull jaw technology to apply a vertical load (a pull test) to ball bonds and stud bumps. Ball shear tests can sometimes promote pad cratering due to the aggressive nature of the bonding process which can weaken the ball bonds.
Stud bump pull testing is applicable where wire bonded stud bumps are used as an alternative to traditional flip chip bumps where shear testing would be applied. Testing the mechanical integrity of these stud bumps is an important part of manufacturing quality control both for wafers and on diced die.
Features and benefits:
- Low force load cell and jaws enables testing of emerging interconnect technology such as copper ball bonds and stud bumps
- Pull tests avoids pad cratering artefacts produced by shear tests
- Copper bonds as small as 50 microns in diameter can be evaluated
- Test is quick to set-up and perform
Download the application note