Test method for confirming contact of probe cards in wafer test

Abstract

The invention discloses a test method for confirming contact of probe cards in a wafer test, which comprises the steps of 1) calling an automatic confirming subprogram used for checking the probe card contact through a test program before the wafer test is conducted; 2) setting a variation range of OD (OverDrive) amount and the variation amount in each time of the OD amount in the automatic confirming subprogram; 3) setting specifications used for checking whether the contact of each bonding pad is good or not; 4) conforming a probe pricking region, and controlling a probe station to move to the probe pricking region through a test instrument; 5) controlling the OD amount of the probe station through the test instrument to change from small to large, carrying out an automatic probe pricking test after each time of variation, and acquiring a result of the contact of each probe; and 6) analyzing the test result of each time. The test method disclosed by the invention can confirm whether abnormity exists in probe card contact test or not in advance, thereby improving the test efficiency and the test quality of wafers, and prolonging the service life of the probe cards.

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. In this way, The contact problem of the probe card is 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 of the means of confirming the needle marks through manual visual inspection become more obvious. The most serious is Basically, it is impossible to confirm that every 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

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