Test Fixtures

There are a myriad of test fixture types, those used on board test systems (ICT and MDA) are well specified and documented. Those for other purposes can take any form, the main types are listed below and Elektrotek can provide immediate quotes for most.

Types of Fixtures

QUICK Fixture

One of the initial problems with a test project is to get an estimate of the test fixture cost, too much specification required etc. To address this we have developed a simple fixture with a few useful features, in addition we have a fixed pricing structure for customisation of the fixture.

• Glass coated clear push plate
• wide latch for easy access
• rigid fiberglass plate
• sloped front panel
• 300mm x 400mm probe plate
• 40mm clearance
• all panels can be detached separately
• 10 adjustable push fingers supplied
• Contact us for an immediate quote

Vacuum Fixture

Vacuum Fixtures are normally used for fully assembled built board tests and are usually seated onto a system specific receiver to provide quick interchange. These can have single or double sided probing. For maximum probe accuracy top and bottom plate alignment is crucial to this end Elektrotek use a double pin and polymer bushing to ensure accuracy. Vacuum fixtures can have very high pin count and are generally the most accurate probing method as they can be built to a high engineering tolerance. Normally Elektrotek use H+W Fixture Kits for manufacture of these fixtures, we can also supply unfinished kits if required. visit www.hwtestproducts.com for more information.

Pneumatic Fixture

Most board test pneumatic fixtures are similar in function to the Vacuum Fixture, except that a pneumatic press is used to push the board under test onto the test probes. Normally these fixtures are simpler than the Vacuum type and are generally less expensive to manufacture.

Mechanical Fixture

Mechanical Fixtures tend to fall into three categories, the Simple Push Down, the Cam Operated and the Multi-Axis.

The Simple Push Down is generally suitable for up to 100 test points, and where the test point targets are reasonably sized. The Cam Type is similar to the Push Down but can be used for higher pin count and has better probing accuracy because the pressing action is directly down onto the UUT.

The Multi Axis fixture can take many forms and be the most complex as it may include UUT pockets, multiple probing blocks together with clamping and marking. These fixtures often have independent and automated controls and are generally used for final function tests.

H+W Fixture Kits

H+W Test Products, Inc., is the largest independently owned test fixture kit manufacturer in the world. Test fixture kits for most major Automated Test Equipment (ATE) testers are available from stock, ready for same day shipments worldwide.

H+W Test Products World Headquarters is located in Seekonk, Massachusetts. They are ready to answer any questions you may have on H+W fixture products, send you product literature and tell you "What's new". visit www.hwtestproducts.com for more information.

Useful Fixture Information

A test fixture in its simplest format is a means of efficiently connecting a series of probes or connectors to a PCB in order to apply signals and make measurements. To do this accurate information is required on the mechanical location of these points and the type of probing required. One item that is often overlooked is an evaluation of how consistent the locations of the points to be probed are, from unit to unit.

• Probes: www.qatech.com
• Probes: www.ingun.co.uk
• Probes: www.idinet.com
• Fixture Kits: www.hwtestproducts.com
• Fixture Kits: www.feinmetall.de
• General Info: www.checksum.com

How Fixtures Are Made