Lossless unsealing method for axial lead diode chip

Abstract

The invention discloses a lossless unsealing method for an axial lead diode chip, and the method comprises the steps: fixing a diode to be packaged according to a specific direction through a diode auxiliary fixing clamp, and carrying out the abrasion cutting of the diode to be packaged, so as to remove a specific part of the diode to be packaged through a physical method; then, the diode chip is taken out from the packaging body in a lossless mode through a specific lossless unsealing method, any damage to the chip in the process of taking out the diode chip can be effectively avoided, metallization on the surface of the chip is removed, and the quality state and defect condition of the surface of the silicon chip are visually checked; and a technical approach is provided for chip inspection in reliability analysis work of DPA, FA and the like.

Description

technical field [0001] The invention belongs to the technical field of semiconductor devices, in particular to a non-destructive unsealing method for an axial lead diode chip. Background technique [0002] Axial leaded packaging is the main packaging form of diodes, and it is an important technical means to realize the miniaturization and weight reduction of diodes. Typical axial leaded diodes include two types of chip mounting methods: metallurgical bonding and non-metallurgical bonding. Non-metallurgical bonding is to use pressure contact to connect the chip to the lead post. The contact resistance between the chip and the lead post in non-metallurgical bonding is relatively large, and under the influence of thermal stress, mechanical stress and other factors, the contact resistance There will be relatively large fluctuations, which will affect the parameters of the conduction voltage of the diode, and then affect the use of the device. Metallurgical bonding is to directl...

AI Technical Summary

Problems solved by technology

In the current reliability analysis work, the method of mechanically destroying the glass shell on the surface of the diode or using hydrofluoric acid to corrode the glass shell is usually used to achieve the purpose of uncapping the diode. The chip is broken in the middle, and the morphology of the active area of ​​the chip cannot be checked from the front of the chip. When using hydrofluoric acid to open the cap, since the glass shell is taken out, but the chip is still directly connected to the lead post, the device is taken out from the hydrofluoric acid or in the The chip will be damaged during the cleaning process

Therefore, due to the structural characteristics of axial leaded metallurgical bonding diodes, it is difficult to completely remove the diode chip from the package by traditional uncapping, and it is easy to introduce crack damage during the unpacking process, which affects the judgment of the original state of the chip.

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