Wafer Testing: Critical Steps to Ensure Chip Quality and Performance

Wafer testing is a pin test of each die on a wafer. A probe made of gold wire is mounted on the test head to make contact with the pads on the die to test the electrical properties of the die. Failed dies will be marked, and when the chip is cut into individual wafers, the dies marked as failed will be removed from the next process to avoid additional manufacturing costs.

Wafer testing is a very important step after wafer fabrication is complete.wafer testing This test is the report card for the wafer manufacturing process. During the test, the electrical performance and circuit function of each chip is examined. Wafer testing is chip classification or wafer classification.

During the test, the wafer is placed in a vacuum chuck and aligned with a very thin probe electrostatometer while the probe makes contact with each pad of the chip, testing the circuitry and recording the results. The number, sequence and type of tests are controlled by a computer program. The tester is automated so that testing after the probe electrometer is aligned with the first wafer (manually or using an automated vision system) does not require operator assistance.

The test addresses three objectives. First, to identify qualified chips before the wafers are sent to the packaging plant.wafer probe Second, to evaluate the electrical parameters of the device circuitry. Engineers need to monitor the distribution of parameters to maintain the quality level of the process. Third, accounting for qualified and defective chips will provide comprehensive performance feedback to the wafer manufacturer. The location of qualified chips and defective products on the wafer is recorded on the computer in the form of a wafer map. In the past, older technology drew a dot on a defective chip.

Wafer testing is one of the major chip yield statistical analysis method issues. With the increasing area and density of chips in China, companies are making wafer testing more and more expensive. As a result, chip technology requires longer test work time management as well as more sophisticated and complex power supplies, mechanical devices and computerized information systems to perform functional test work and monitor test study results.probe holder The visual inspection control system aspect is also us more sophisticated and expensive as our chip size expands. Chip designers are being asked to introduce test data patterns into storage arrays. Test design professionals are exploring ways to simplify and streamline the test process, such as using simplified test applications after the chip parameters have been evaluated and qualified, and also testing chips on wafers in interlaced rows, or testing multiple chips at the same time as they are being tested.