on wafer
Wafer testing is a key part of semiconductor manufacturing, which ensures that each chip is fully functional before dicing and packaging, effectively eliminating defects and controlling production costs.
Through testing, the electrical performance and stability of the chip can be evaluated to provide assurance of product quality, while providing feedback on process information to optimize the production process.
on wafer
Preparation before testing:
The wafer will be cut, polished and other treatments to make its surface flat and clean.
Wafer Positioning: Select the appropriate probe table for each chip on the wafer to contact, test machine and debugging to ensure stable equipment operation.
Test its basic electrical characteristics, such as threshold voltage, current characteristics.
Measure the performance parameters of the chip to ensure that they are within specification.
Verify that the chip performs its intended function, which may range from simple logic tests to complex system-level measurements.
Probe contact: Utilizing probes to make contact with the pins of the chip to achieve electrical signal transmission.
Signal Test: Perform various signal tests (e.g. DC parameter test, AC parameter test, timing test, etc.) on the chip according to the test program to evaluate the performance and stability of the chip.
simulates the effect of temperature change on the chip to assess its reliability.
Troubleshooting: Troubleshooting and repairing or rejecting the chip when it is found to be faulty in the testing process.
Data processing after testing:
Classify the chips on the wafer as good, repairable or defective according to the test results.
Feedback the test results to the design and production departments in order to optimize the chip design and production process.
