WS Test Before Packaging for Chip Testing

Previously I introduced wafer acceptance test, the first step of chip testing. This test step is the first test after the chip is designed and produced, so wafer sorting is needed after wafer acceptance test. This issue introduces the specific concepts and knowledge of wafer testing.

Chip Wafer Testing

Wafer Sort (WS), this step is all the wafer process (including bumping) to complete their own after the completion of the technical performance of the chip parameters of the test, divided into Full sort (all through the test) and Sample sort (sampling analysis test),wafer test this step of the test system parameters are FT test results data can be part of the enterprise or company All, the way for the use of probes must be stuck in each of our Chinese chip bumping after the copper column and then give the relevant research and testing environment resources.

Upon completion of the test, a map will be generated and marked failed chips. In the subsequent packaging process, these unqualified chips will be removed according to this map and will not be packaged, reducing packaging costs. The results of this phase of testing can also be used after FT test issues. The on-resistance Rdson, a typical example of an integrated top and bottom tube buck chip, is a key performance parameter,wafer level testing and both the WS test and the FT test measure the relevant parameter. If the FT on-resistance test result is not normal and the WS test result is OK, then the problem is clearly in the packaging plant, which helps us to find the problem, as well as other relevant parameters such as leakage current.

Chip Test System

So to summarize, WS test is an advanced test before chip packaging,failure analysis as opposed to FT test, with the purpose of collecting data to reduce subsequent packaging costs.

Chip Wafer Testing WS Test

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