Wafer testing method used for design analysis purpose

Abstract

The invention provides a wafer testing method used for a design analysis purpose. A redistribution layer is manufactured on the surface of a manufactured wafer, a plurality of first pads of a chip of the wafer are connected with a plurality of second pads which are located on the redistribution layer and correspond to the first pads through redistribution layer connecting wires, the second pads on the redistribution layer are located outside the area detected by a microprobe, testing stimuli are inflicted in the positions of the second pads on the redistribution layer with a probe of a probe card, signal testing is carried out on the chip with the microprobe, the probe of the probe card and the microprobe are separated physically, and the probe of the probe card and the microprobe are not affected by each other. The wafer testing method used for the design analysis purpose widens the range of the contact of the microprobe and chip to the maximum, ensures that the signal testing can be carried out normally and obviously promotes efficiency of detecting signals.

Description

technical field [0001] The invention relates to the field of semiconductor design and testing, in particular to a wafer testing method for design and analysis purposes. Background technique [0002] In the development stage of large-scale integrated circuits, it is very important to perform verification analysis on the initially produced circuits. Only after the first batch of wafer process is completed, it is possible to verify whether the simulation model is correct and whether the chip is working properly, and it is possible to conduct more extensive tests under different conditions to find the weak link of the chip design. Because of this, the first batch of wafers will be tested more extensively than later mature wafers, some specific analytical instruments and devices will be used, and even the process and standards of the first batch of wafers will be different, such as ML wafer (ML wafer technical term, refers to the metal layer on the wafer surface) and PT wafer (P...

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Problems solved by technology

This process can take hours and even risk damaging the chip

And changing the probe card means changing the test conditions. For different probe cards, there are different winding methods and lengths. It is very likely that the test results will not be comparable under certain conditions.

[0007] Even if different probe cards are used, since the pins on the probe card must be in good contact with the bonding pad (pad) to ensure the normal operation of the chip, the active area of ​​the opening and the micro-probe is very limited, and it must be ensured that it does not contact the probe. When the needles on the needle card are short-circuited, adjust the position and angle of the microprobe to contact the wafer surface, resulting in unstable signals and affecting the accuracy of test results

[0008] There are openings on the probe card PCB4, and the needles of the probe card need to be installed at a certain angle. The probe card PCB4 with openings is not strong, the stability of the inclined needles is not good, and the spring constant of the needles is not good, causing the probe Good and reliable contact cannot be guaranteed after several contacts between pin card and wafer

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