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Dev Fixture Design Guidelines ​

This page provides best practices and component recommendations for building reliable Dev series test fixtures. Follow these guidelines to ensure optimal performance, ease of assembly, and cost-effectiveness.

Guide Pins ​

  • Spring guide pins are the preferred method for accurately locating the DUT (Device Under Test) within the fixture.
  • If the DUT’s locating holes are smaller than 3mm (minimum 2.5mm), use a custom cradle for positioning.
    • Cradles should be mounted to GP2-T or GP2-TL guide pins using M3 screws for secure and repeatable placement.

Pressure Pins ​

  • Use 45mm pressure pins for all Dev fixtures.
  • Pressure pins are attached to the pressure plate with M3 x 10mm screws, providing consistent downward force on the DUT.

Receptacles and Probes ​

  • Generic receptacles and probes are recommended for Dev fixtures, offering the best balance of cost and performance for short-lifecycle applications.
    • Premium options are available, but are generally unnecessary due to the fixture’s limited lifespan.
  • Use the "2" style collar (2.5mm collar height) for compatibility with standard pressure pin lengths.
    • If using a different collar height, adjust the pressure pin length accordingly.
  • Probe tip selection:
    • Use LM2 tips for standard test points.
    • Use A2 tips for populated through-hole connections.

Probe Plate ​

  • Design the probe plate with cutouts to avoid interference with tall components on the DUT, ensuring proper fit and probe access.

Fixture Assembly Instructions ​

DUT Mating Height ​

  • Position the DUT so that its bottom surface is 3.5mm above the probe plate. This height is optimized for use with a 45mm pressure pin and a 2.5mm collar.
  • Use a mounting or tooling hole on the DUT for precise and repeatable alignment.

DUT Mate

By following these recommendations, you can achieve robust, repeatable, and cost-effective Dev fixture assemblies.