How to: Wire Pull

We recently published How To: Wire Pull, a guide advising what to consider and how to best perform a Wire Pull test. The main focus of the manual is on wire- and ribbon pull using wire hooks. Loop height measurement is also covered. The how-to briefly touches on surrounding topics like tweezer pull and peel testing of wires, which will be the subject of a separate future how-to by xyztec.

How to: Wire Pull Testing?

Wire Pull Testing applies an upward force under the wire, effectively pulling it away from the substrate or die. The purpose of the test is as MIL-STD-883 2011.9 describes it: “To measure bond strengths, evaluate bond strength distributions, or determine compliance with specified bond strength requirements”. A wire can be pulled to destruction, but there are also non-destructive variants whereby one tests whether the wire can withstand a certain force. Non-destructive test methods are typically used for 100% testing of safety critical, high quality and high cost products, avoiding damage to the acceptable wired bonds tested.

What is wire pull?

The term Wire Pull usually refers to the act of pulling a wire with a hook mounted on a pull sensor on a bond tester. However, to promote certain failure modes, wires can be cut and then pulled by tweezers, also mounted on a pull sensor on a bond tester. Wire Pull is sometimes abbreviated to WP. Our wire pull test type page contains videos of both thin wire pull testing and thick wire pull testing.

Usually wires up to 75µm diameter (3 mil) are classified as thin wire. Beyond that size, we speak about thick wire testing.

Index

1. Introduction
2. What is Wire Pull?
3. What kind of wires can be tested?
4. Objectives
5. Tool design
6. Tool quality
   • Material and damage
   • Hook concentricity
7. Alignment
   • Quick manual testing of thin wire
   • Auto hook
   • DVS 2811
   • Triangulation
   • Automation and wire detect
8. Loop height measurement
9. Work holder and clamping
10. Variants on wire pull
    • Vector pull
    • SMD gull wing leads
11. Test method settings
    • Test definition
    • Statistical Process Control (SPC)
    • Data analysis
    • Data export
12. Failure modes
    • Gold wire
    • Aluminium wire
13. Appendices

Learn more about the Sigma

If you are interested in a live demonstration of the Sigma on your sample or perhaps for more bond testing inspiration, contact us today! Also, did you know we have a consumables webshop, via which you can order tools at a 10% discount using promotion code SUMMER16? The promotion code is valid until the end of August 2016.