Preserving Hook Position and Loop Geometry in Wire-Pull Evidence

A wire-pull report is more useful when each force can be traced to the wire geometry and hook placement that produced it. An anonymous list of forces can hide differences between loops, bond locations or test access. Plan the location record before destructive testing begins.

Identify the wire and loading arrangement

Xyztec’s wire-pull overview emphasizes hook alignment for reproducible measurements and distinguishes destructive from nondestructive testing. The selected procedure should define which route applies and how the actual loop is loaded.

Record wire material, diameter or ribbon geometry, bond positions and package orientation. Preserve a pretest image showing the loop where practical. If the investigation compares two bond processes, confirm that their specimen geometries are also represented.

Prepare a test-location map

Check access before testing a dense group of wires. The hook should engage the intended wire according to the procedure without unintentionally loading a neighbor. An automated program still needs validation on the actual geometry and positional variation.

Review the event, not only its peak

Retain force data and post-test images. If a wire slips from the hook, contacts another feature or is loaded at an unintended position, assess validity under the agreed method. Document the reason for any excluded result.

For example, a high force followed by failure in the wire should not be described automatically as the strength of a specific bond interface. The observed failure location determines which part of the construction limited the test.

Keep the sequence visible when one broken wire changes access to another. A later test should not silently use a different loading route merely because the original route became inconvenient after the first pull.

If loop geometry varies visibly within the sample, keep those groups distinguishable in the data. A comparison organized only by specimen number may otherwise combine several loading geometries and obscure why some force or failure results differ.

Compare equivalent test conditions

Align hook placement, pull direction and loop geometry before comparing process averages. Use the applicable acceptance requirement and avoid inventing a universal force threshold across wire sizes or package constructions.

State the tested population and whether the evidence is screening, qualification or failure analysis. A nondestructive screen and a destructive strength study answer different questions and should remain separately labeled.

The ball-shear guide covers another bond-test geometry, and sample planning helps preserve material for complementary examination.