Scanning Electron Microscopy

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A Scanning Electron Microscope is a type of electron Microscope that images a sample by scanning it with a high-energy beam of electrons in a raster scan pattern. The electrons interact with the atoms that make up the sample producing signals that contain information about the sample's surface topography, composition, and other properties such as electrical conductivity. The signals result from interactions of the electron beam with atoms at or near the surface of the sample. In the most common or standard detection mode, secondary electron imaging or SEI, the SEM can produce very high-resolution images of a sample surface, revealing details less than 1 nm in size. Due to the very narrow electron beam, SEM micrographs have a large depth of field yielding a characteristic three-dimensional appearance useful for understanding the surface structure of a sample. This is exemplified by the micrograph of the component surface shown to the right. A wide range of magnifications is possible. These can range from nearly 10 times (equivalent to that of a powerful hand-held lens) to more than 500,000 times, which is about 250 times the magnification limit of the best light microscopes available on the market today.

The scanning electron microscope (SEM) test provides some of the most detailed, in-depth visual analyses of components coming through SMT Corporation. The microscopes are used strictly for counterfeit detection and have allowed us to find evidence of counterfeiting where other tools were unable.

Information Obtained

• Surface topography
Differentiation between surface texture
Observation of grain boundaries in unetched samples


Instrumentation

Hitachi S-3000N (1 Unit)
This scanning electron microscope (SEM) specifically for counterfeit component investigation. The capabilities of the SEM will allow us to magnify to 300,000x (300 kx) in order to inspect key areas of components not visible by even the best light-microscopes.

Tescan Vega 3 SBU (2 Units)
Utilizing a variable pressure system this SEM is a more moden take on counterfeit component investigation. A smaller footprint and a multitude of features allows for uncoated, non-conductive samples to be viewed in their natural state. Maximum magnification is 300,000x (300 kx).

 

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