Challenge

An existing pull-test method was used to assess the attachment strength of a micro, bonded component. The method of applying the test load presented practical difficulties and had the potential to influence the measured result. A more robust and repeatable means of applying the load was required while maintaining the integrity of the component and bonded interface.

Engineering Approach

A detailed investigation of alternative load-application methods was undertaken. Concepts investigated included miniature mechanical clamping, micro-machined holes and slots, and bonded attachment features. Candidate approaches were assessed through background research, mechanical and stress analysis, manufacturability assessment and practical consideration of test preparation and execution. The investigation included precision micro-machining, diamond tooling, ultrahigh-speed drilling, femtosecond laser machining, precision multi-axis fixturing, miniature clamping systems and high-strength bonded attachments.

Outcome

Alternative test concepts were developed and evaluated, providing a technical basis for selecting a more robust method of applying the pull-test load.