Electro Technical Products, Inc.
Test Fixtures
Over the years, Electro Technical Products, Inc has become equipped to build test fixtures capable of withstanding the rigors of the manufacturing floor while keeping the overall concept direct and functional. Here are a few fixture examples, some old and some new; all are still in use.
Designed and delivered as a primary factory PCB test fixture for a "Voice over Internet" company. The project included design and fabrication of the dual card fixture including test application programming. This fixture performs individual and combined board tests for two boards as well as device programming for their 2 Atmel, 1 PSOC and 1 dsPIC processors. After individual board tests and flashing, an integrated primary systems test of the mated pair is conducted. Total development time including test programming was approximately 9 weeks.
This fixture, additionally, provides butterfly configuration of normally stacked PCBs for use in the engineering laboratory for analysis and debug when not in use in the factory.
The left hand photo is the bed-of-nails CAD design of the dual board fixture which models all fixture pc boards, including the clients DUT boards with critical components installed to check clearances and alignments. It was determined that a custom enclosure was not required as all external connections could be made directly to the attached equipment. The right hand photo is the completed and delivered fixture. The left hand board fixture handles the primary system board. The right hand fixture tests one particular daughter board. The fixture was designed, on customer request, with the ability to change out the right hand fixture in order to accommodate new fixtures for updated or alternate daughter boards.
In this design we were required to integrate primary factory card test and system with a Blackberry Smart Phone. The project included design and fabrication of the card fixture interacting with peripheral equipment and the Blackberry as well as doing the test programming. The fixture combines individual and combined board tests for the system board as well as the flash programming for 1 Atmel, 1 Freescale ARM 9 processors. After DUT board tests and flashing, an integrated primary systems test of the system board under test was conducted. Total development time including test programming was approximately 7 weeks.
Again, the right hand photo is the bed of nails CAD design as well as a custom enclosure to integrate the various system components of the fixture. The CAD design allowed all circuit boards, interface and controls and collateral equipment to be virtually installed before the build, to check clearances and alignments. As with all of our designs, ALL test points on the DUT are designed into the bed-of-nails portion of the fixture, even if not called for in the test. This foresight proved critical as the customer decided additional features were to be added to the test plan.The left hand photo shows the completed and delivered fixture.
The left hand board fixture handles the primary system board. The right hand fixture tests one particular daughter board. The fixture was designed, on customer request, with the ability to change out the right hand fixture in order to accommodate new fixtures for updated or alternate daughter boards.
This is one example of a number of fixtures we were involved in designing for a known communications company. In this particular fixture we were required to implement all of the interconnections which would allow the individual components of a new radio to be arranged in a butterfly configuration to allow for probing and line test. As with most of our designs, this design was required to be designed to be duplicated.
As the requesting company has an extensive production and engineering test facility we were not required to provide any test programming. The mechanical system were CNC milled to high precision to permit proper butterfly fit of both the DUT boards as well as their interconnects.
This fixture is for a compact RF prisoner detention tracking device and acts as a bed of nails for factory testing. The fixture was developed to permit flashing of the imbedded Atmel processor as well as alignment of the RF section of the board before final assembly and encapsulation.
As a function of involvement with the design of a certified laser light medical treatment device, it was required that the factory be able to provide a certification that the emitted energy fell within the certification guidelines. This fixture measures the sum total emitted energy of all laser diode emissions and provides a pass fail indication. The precision milled component insures that each laser diode is measured independent of the emission of the others which are on at the same time. Note the parts bin as the chassis for the unit. This is a good example of a low cost unit that gets the job done.