5 Questions You Should Ask Yourself About Fixturing

Fixturing, or the mating harness used to connect a device-under-test to the tester, can often be as susceptible to errors as the device being tested. Fixturing takes time to build and can be costly to repair or replace. Cirris offers 5 questions to evaluate the efficiency and durability of your fixturing.

1. How often should I verify my fixturing?

Many shops validate fixtures on a yearly basis. Other shops replace or recheck fixtures after a predetermined amount of cycles of wear. Some shops may wait until the fixturing fails.

The time spent to troubleshoot and repair a fixture will help determine how important it is to proactively maintain your fixturing.

Ask yourself, what does it cost you when a fixture goes bad? Money? Production time? Perceived quality? Customer confidence and good will?

2. Does my fixturing meet test standards?

Since the industry is trying to standardize build and test classifications, you have to show you meet some recognized standard to remain competitive with other shops.

For example, if A-620 were applied to fixturing, Class 1 products might use fixtures until they fail. Class 2 may check fixtures every 1-2 years, or as resistances fall outside of their established parameters. Class 3 could check fixturing at least yearly, and in extreme cases some companies might test fixturing before every test.

3. Should I populate all the pins in my fixturing?

Compared to the labor it takes to trouble shoot assemblies, populating all pins is a onetime cost and not very expensive.

Populating all pins means:

      • You get better error identification from the test if all pins are loaded.
      • You get better testing, since you do not get shorts or high voltage test results on the pins/sockets that are not populated.
      • You can reuse the fixturing and connector on other assemblies using the same connector. If not all the pins are populated you create many variations of the same assembly.

Fixturing is not cheap, so get as much use out of an assembly as you possibly can by populating all pins.

4. Is it better to build my own fixturing or to outsource the work?

This depends on shop rate, expertise in-house, and delivery time.

In shops with dedicated fixture building resources, the work can be accomplished by one person or department. In larger organizations, building fixturing becomes as hard as building high mix and low volume cable assemblies.

Test Equipment companies, like Cirris, see how difficult it is for assembly shops to obtain parts and build fixturing. Many of these high mix low volume test shops produce fixtures. Although the prices can be higher for labor, the savings on this one time setup cost could be worthwhile. If you are price sensitive and have available resources, you can purchase the materials and perform the labor yourself.

For example, Cirris has generic mating cables that only need to be terminated on one end. This can reduce labor and delivery times.

5. What are the best practices for storing fixturing?

This depends on how your shop is setup and what lean practices you employ. Cirris customers have found creative and original ways of safely storing fixtures.

  • Some shops bag and tag devices and use an organization method similar to the Dewey Decimal system.
  • Some shops have automated vertical storage conveyers. The operator types a fixture number into a computer and an attached machine rolls around until it finds the right one.
  • One company even used the dry cleaning conveyer system.

Best practice includes identification numbers for inventory and traceability. No matter your method, be sure to store your fixtures somewhere that is

  • Clean
  • Dry
  • Easy to find
  • Prevents mechanical damage (bent points) or marring of housings
  • Marked with date made, last tested or verified date, and an identifying number/barcode.