Test method for confirming probe card contact during wafer testing

Abstract

The invention discloses a test method for confirming the contactability of a probe card in a wafer test, comprising the steps of: 1) calling an automatic confirmation subroutine for checking the contactability of a probe card through a test program before the wafer test; 2) ) In the automatic confirmation subroutine, set the change range of the OD amount and each change amount of the OD amount; 3) Set the specifications for checking whether the contact of each pad is good; 4) After confirming the needle area, pass the tester Control the movement of the probe station to the needle sticking area; 5) Control the OD of the probe station to change from small to large through the tester, and perform an automatic needle stick test after each change to obtain the contact result of each probe; analysis of the test results. The invention can confirm in advance whether there is any abnormality in the contact test of the probe card, improves the test efficiency and wafer test quality, and prolongs the service life of the probe card.

Description

technical field [0001] The invention relates to a test method in the field of semiconductors, in particular to a test method for confirming the contact of a probe card in a wafer test. Background technique [0002] In the field of semiconductor wafer testing, when testing wafers, first install the probe card on the probe station, and after installing the wafer, insert needles according to the preset OD (OverDrive) measurement, and confirm the needle insertion by manual visual inspection. Whether the trace on the pad (PAD) is within a certain range, if not within a certain range, then adjust it, if it is finally confirmed that it cannot be adjusted, then remove the probe card for inspection, if it is confirmed that it is within a certain range, start the product test After testing some dies, if it is found that there is a contact problem between the probe probe and the pad, which causes the tester to be abnormal, then the wafer can only be reworked for testing, which will aff...

AI Technical Summary

Problems solved by technology

[0002] In the field of semiconductor wafer testing, when testing wafers, first install the probe card on the probe station, and after installing the wafer, insert needles according to the preset OD (OverDrive) measurement, and confirm the needle insertion by manual visual inspection. Whether the trace on the pad (PAD) is within a certain range, if not within a certain range, then adjust it, if it is finally confirmed that it cannot be adjusted, then remove the probe card for inspection, if it is confirmed that it is within a certain range, start the product test After testing some dies, if it is found that there is a contact problem between the probe probe and the pad, which causes the tester to be abnormal, then the wafer can only be reworked for testing, which will affect the efficiency of the test and the reliability of the pad. Number of needle sticks

Due to a certain situation, there are strict requirements on the number of needle sticking of the pad, and when there is a contact test problem in the test, it will affect the yield of the product (such as figure 1 shown)

[0003] At present, in the semiconductor wafer test, in order to improve the test efficiency, the general probe card design adopts the method of multi-DUT (Device Under Test, device under test) simultaneous test, such as 16DUT, 32DUT, 64DUT or even 128DUT, 256DUT or more. Stuck contact problems are more likely to occur during the test, and it is more difficult to achieve synchronous monitoring during the test process, and when there are more DUTs on the same side, the limitations brought about by manual visual inspection to confirm the needle marks become more obvious. The most serious is the basic It is not possible to confirm that each probe is on the pad, and even if no abnormalities are found in the traces, it cannot be guaranteed that there will be no problems in the contact test during the test.

In addition, when the probe material of the probe card is a ReW (rhenium tungsten) needle, its needle-stick marks on the pad can still be seen clearly. When the probe material is softer than the ReW needle, its needle-stick marks on the pad Can not be seen clearly, so the method of confirming the needle stick marks by manual visual inspection becomes unreliable

Images