Mechanical Reliability test

Created: 6/09/2020Last Updated: 6/09/2020

Introduction

Mechanical reliability tests are essential for testing the electronic products under different mechanical stresses.

Background

The passing criteria for mechanical reliability is to ensure no noticeable cosmetic damage, no noticeable mechanical damage , no electrical failure, and lastly no product functional failure.

Overview

Vibration

    • This test applies high frequency vibration on the electronic product in each of axial directions to test if the product does not become loose and product is functional.

Drop

    • This tests drops the electronic product from a defined reasonable height and see if the electronic products is still functional.
    • Typically drop test is performed at four sides and two surfaces.

Connector

    • Cycling Test: Repeatedly pull the cable out of the connector (e.g. HDMI Cable from the HDMI perceptible)
      • A genera acceptance criteria is that the device withstand 100s of pulls and the the connector can still be inserted
    • Load test: Apply a perpendicular force on the connector with cable inserted in. This simulates external forced applied on the connectors while inserted to the receptacle.
      • A general acceptance criteria is that there is no mechanical failure that results in foundational failure.

Tumbling

    • This test is conducted by placing the electronic device inside a long mechanical square tube with various lengths. Then this tube is rotated.
    • Application:
      • A portable device generally goes through this test.

Summary & Conclusion

  • Vibration tests the mechanical and electrical components structural integrity under high frequencies in 3 product axis.
  • Drop tests the the mechanical and electrical components structural integrity under a predefined height.
  • Connector tests mechanical integrity of the connector and receptacle under different mechanical stress such as cable yank and connector side load test.
  • Tumbling tests the mechanical and electrical components structural integrity under repeatedly tumbling with different distances.

Mechanical readabilities is essential for device that is portable and have connectors that are used often. An system design engineer will pick mechanical parts that has the best rigidity and use the under-fill and potting on electrical components on the PCB to improve product reliability under vibration and drop tests.