Evaluation of Adhesive Bonds


Image of epoxy underfill beneath flip chip, showing void in center

Image of epoxy underfill beneath flip chip, showing void in center

Adhesive bonds have broad applications

Automotive: body panel assembly
Semiconductor packaging: flip chip and die attach
underfill

Performance requirements

  • High strength
  • High thermal conductivity
  • High electrical conductivity

Manufacturing challenges

  • Stabilize spread of adhesive
  • Maintain thickness value
  • Insure good adhesion

Solution: laser ultrasonics

  • Non-contact operation
  • Fast areal scanning
  • Small laser spots, yielding high spatial resolution
  • High bandwidth for measurement of bond strength
  • Replacement of slow water-based ultrasonic systems
Image of adhesive distribution underneath sheet metal

Image of adhesive distribution underneath sheet metal