A handler moves each tested device under test (DUT) from its test site to an appropriate physical bin (hardware bin), depending on the test results. The tester software assigns each tested DUT to a hardware bin and communicates with the handler to ensure that the handler places the DUT in the appropriate hardware bin.

Typically, the handler places passed DUTs in one or more hardware bins, depending on the grade of the DUT, and places failed DUTs in multiple hardware bins, depending on the type or condition of failure.

Because handlers have a limited quantity of hardware bins available, the tester software also assigns each DUT to a virtual bin defined in software (software bin) to provide a more detailed classification of test results. The tester software records the software bin for each DUT in a Standard Test Data Format (STDF) log file for additional analysis after testing completes. When wafer testing, the prober assigns hardware bins to individual die based on the test results. Because probers generally do not have the same limitations as handlers on the number of hardware bins they support, the set of software bins can be identical to the set of hardware bins when testing wafers. Use the Bin Definitions Editor and enable the Software Bins Only option to ensure that software bins and hardware bins are the same.

TSM Implementation

Use the Bin Definitions Editor to define the software bins and hardware bins for the test program, define how the software bins relate to hardware bins, and define the default software bins in the test program. The TSM installs a bin definitions XML schema, located at <TestStand>\Components\Schemas\NI_SemiconductorModule\BinDefinitions.xsd, which you can use to create a valid bin definitions file. Use the Bin Definitions File Path control on the Bin Definitions panel of the Test Program Editor to specify the bin definitions file to use with the test program.

The test program refers only to software bins. Because each software bin is associated with a hardware bin, the tester assigns a hardware bin to a DUT when it assigns the associated software bin to the DUT.

Each instance of the Semiconductor Multi Test step contains one or more tests for which you can specify the software bin to assign to the DUT when a test fails. When you specify a valid bin definitions file on the Bin Definitions panel of the Test Program Editor, you can use the Software Bin column on the Tests tab to select a software bin defined in the bin definitions file.

In addition, you can use a Set and Lock Bin step to arbitrarily assign a software bin to a DUT. Use the Bin Expression control on the Set and Lock Bin tab to specify an expression that evaluates at run time to a valid software bin number defined in the bin definitions file. The step assigns a software bin to the DUT and locks the bin by preventing tests on subsequent Semiconductor Multi Test steps from assigning a bin to the DUT when the test fails. You can use the Set and Lock Bin step to implement grading in the test program.