A kind of brittle fracture method of flexible film

Abstract

The invention relates to the field of scanning electron microscope sample preparation and particularly relates to a flexible film brittle failure method. The flexible film brittle failure method comprises the following steps of: processing a silicon wafer into a long and thin strip, thereby obtaining a pre-carved silicon wafer; bonding the pre-carved silicon wafer and a flexible film; fixing two ends of the silicon wafer with clips, and then feeding the silicon wafer into a cooling liquid so as to fully cool the silicon wafer; rapidly taking out the frozen silicon wafer, bending the frozen silicon wafer towards a side with a slot until the frozen silicon wafer is subjected to brittle failure, thereby obtaining a flexible film subjected to brittle failure. In a process of reducing the flexibility of the film at a low temperature, the method is capable of limiting film movement by virtue of binding of the pre-carved silicon wafer, concentrating transient stress and generating high strain rate, thereby easily obtaining a complete brittle fracture surface and overcoming various problems of obvious plastic deformation, unevenness and the like of the prepared fracture surface.

Description

Technical field [0001] The invention relates to the field of sample preparation for scanning electron microscopes, in particular to a method for brittle fracture of flexible films. Background technique [0002] It is often necessary to use scanning electron microscopy to observe the in-situ morphology of the flexible film section in research. However, the flexible film material has the characteristics of thin thickness, soft material and high strength. It is very difficult to prepare the sample. If it is cut or torn, it will plastically deform the section and destroy the original morphology of the section. The current commonly used method is to cut the film into small strips and then immerse them in liquid nitrogen. This is because the temperature of liquid nitrogen is about -196℃, organic matter will become brittle at low temperature. After the sample is cooled and brittle, use two tweezers to clamp the strip, and then bend to the middle to break the sample, thereby obtaining a...

AI Technical Summary

Problems solved by technology

However, this method of operation has the following problems: first, it is difficult to hold the small sample with tweezers, and it is easy to lose due to collapse after breaking; Or produce obvious plastic deformation, or even break apart; third, some samples still have partial plasticity at the temperature of liquid nitrogen, and cannot be completely brittle

[0003] In the invention patent with the application number 201410563142.9, a device for freeze-fracture of scanning electron microscope samples is mentioned. Although this device solves the problem of insufficient liquid nitrogen precooling in the freeze-fracture process of existing scanning electron microscope samples, but The overall equipment is huge, complicated to manufacture and complex to operate, which greatly limits the popularity of the above-mentioned devices

In the invention patent with the application number CN201410637248.9, a low-temperature brittle fracture device for preparing scanning electron microscope sample sections is mentioned. The device is huge and consumes a lot of liquid nitrogen, which is not suitable for flexible film samples, especially small-sized samples.

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