Analysing using Optical Microscopy (OM)
Technical principles
The imaging principle of an optical microscope is to use visible light to illuminate the surface of a test piece to cause local scattering or reflection to form different contrasts. However, because the wavelength of visible light is as high as 4000-7000 angstroms, the resolution (or discrimination rate, resolution energy) of the system is Refers to the shortest distance that two points can be distinguished), it is naturally the worst. Under normal operation, since the discrimination rate of the naked eye is only 0.2 mm, when the optimal resolution of the optical microscope is only 0.2 um, the theoretical maximum magnification is only 1000 It is the largest imaging system, which shows that observations with optical microscopes can actually still provide a lot of preliminary structural information.
Machine type
Analytical applications
Although the magnification and resolution of optical microscopes cannot meet the needs of surface observation of many materials, they are still widely used in the following applications, such as:
Observation of component cross-sectional structure;
Planar delayered structure analysis and observation;
Observation of Precipitate Free Zone;
Observation of poor alignment and overetching (Overetch) dents;
Research on Oxidation Enhanced Stacking Faults (OSF), etc.
What is the maximum magnification of an optical microscope?
Optical microscope magnification mainly relies on the objective lens to actually magnify the object, and the eyepiece to secondary magnify the image magnified by the objective lens. The objective lens of an optical microscope can only go up to 100 times, and the eyepiece can only go up to 10 times.
16 times
The maximum eyepiece is 20x. Therefore, when the objective lens is 100 times and the eyepiece is 20 times, the total magnification can reach 2000 times. But 2000 times is only a numerical 2000 times, not a true magnification of 2000 times. For example, when the eyepiece is 10x, the objective lens is 100x, and the total magnification is 1000x, because the actual magnification objective lens is still 100x, but the eyepiece is changed from 10x to 20x. Looks 2000 times
1000 times, a difference of twice, but in fact it is only a difference of 10 times.
