Board stiffeners (sometimes called load board stiffeners, test board stiffeners, DIB stiffeners, or PIB stiffeners) are used, as the name implies, to "stiffen", or support a printed circuit test board for semiconductor testing.

Test boards require this type of support to counteract the effects of the pressure used to compress the IC being tested into its test socket(s).  This pressure is usually provided by an automated test handler and can vary from a few pounds to over 500 (227kg.) pounds or more.

In addition, the stiffener serves as an attachment and alignment point for the load board and as the primary interface to the tester electronics.

Stiffeners can be used for final test, system test, and probe.