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Acronyms, Abbreviations, and Other Terminology ​

The test fixture and circuit board engineering worlds contain many different acronyms and abbreviations. This section defines the various acronyms, abbreviations, and other terminology that we use at FixturFab.

Acronyms ​

  • DFM
    • Design for Manufacturing
  • DFT
    • Design for Test
  • DUT
    • Device Under Test
  • FCT
    • Functional Circuit Test — testing that verifies a board functions as designed
  • GP
    • Guide Pin
  • MTM
    • Acroname Manufacturing Test Modules
  • NRE
    • Non-Recurring Engineering — the one-time design cost for a custom component such as a cartridge or feedthrough plate
  • PCB
    • Printed Circuit Board
  • PCBA
    • Printed Circuit Board Assembly
  • TP
    • Test Point
  • TPCB
    • Test Point Carrier Board

Fixture tiers ​

FixturFab fixtures come in three tiers — see fixture tiers for the full comparison.

  • Dev
    • Monolithic, lowest-cost fixtures for early prototyping (~1,000 test cycles)
  • Dev Pro
    • Stock base with custom cartridge; the recommended starting point for most teams (~5,000–10,000 test cycles)
  • Production
    • Industrial-grade base with custom cartridge, built for sustained high-volume testing (millions of test cycles)

Test Fixture Terminology ​

  • Cartridge
    • Replaceable/modular set of plates that is customized for testing a Device Under Test (DUT)
  • Feedthrough Plate
    • Connector Plate on Test Fixture that various feedthroughs, mass-interconnects, and other panel mount connectors are mounted.
  • Fixture Base
    • Mechanical Fixture Base that a Cartridge will be mounted within
  • Guide Pin
    • Spring-loaded or fixed pins that engage mounting holes on the DUT to ensure accurate, repeatable positioning
  • Probe
    • Test Probe or Pogo-Pin
    • Replaceable spring probe that makes electrical contact with the DUT
  • Probe Plate
    • The plate in which receptacles are mounted; positions probes to align with test points on the DUT
  • Pressure Plate
    • The moving plate that applies downward force on the DUT; pressure pins mount to it to distribute force across the board
  • Receptacle
    • Container that a test probe is pressed into
    • Allows for probes to be easily replaced
  • Test Point Carrier Board
    • Replaces hand-wiring by routing test point signals through a PCB to standard connectors — you plug cables into connectors instead of managing individual wires
    • Also known as an interface board from other suppliers
    • Comes in three variants:
      • Auto TPCB — FixturFab automates the design; handles signal routing only. Typically worthwhile at ~50+ test points or for multiple fixtures of the same design
      • Consigned TPCB — you design the TPCB following FixturFab's published guidelines and we integrate it; you own and can iterate the signal routing design
      • Turnkey TPCB — FixturFab designs a custom TPCB with support circuitry beyond signal routing (power conditioning, relay switching, instrumentation integration); scoped as a Test Solutions engagement

Fixture Process Terms ​

  • Contact Force
    • The downward force applied to ensure reliable probe-to-test-point contact, measured in Newtons (N). Development fixtures typically provide up to 200N; production fixtures up to 2000N
  • Cycle
    • One complete test sequence: fixture close, test execution, fixture open. Cycle count determines fixture and probe wear
  • Probe Travel
    • The distance a probe can compress while maintaining contact; also called working stroke