Jul 15, 2021 solar cell

The working principle and use method of metallurgical microscope

The metallographic microscope is mainly used to identify and analyze the internal structure and organization of metals. It is an important instrument for studying metallography in metallurgy and a key equipment for product quality identification in the industrial sector. This instrument is equipped with a camera device that can capture metallographic maps and Measure and analyze the map, edit, output, store, and manage the image. Due to its easy operation, large field of view, and relatively low price, the metallurgical microscope is still the most commonly used instrument in routine inspection and research work. According to its optical original configuration, wnlo-onff uses it for inspection, analysis and measurement of semiconductor materials and devices, various crystals, and integrated circuits. Here we take OLYMPUS BX51 as an example to introduce.
(1) Features of OLYMPUS BX51:
①Achieve various observations of bright field, dark field, differential interference, and polarized light.
②Provide high-definition CCD connection and software measurement system.
③It has transmission and reflection observation functions.
(2) OLYMPUS BX51 equipment hardware configuration:
①Eyepiece: 10x.
②Objective lens: 5x, 10x, 20x, 50x, 100x.
③The magnification is 50x ~ 1000x.
④Movement range: X =76mm, Y = 52mm.
⑤Up and down stroke of focusing mechanism stage: 25mm.
⑥The fine adjustment range is 100μm, the minimum scale unit is 1μm, the tension of the coarse adjustment knob is adjustable, and the upper limit is stopped.
⑦Objective lens turntable: 5-hole turntable.
⑧Maximum specimen height: 65mm.
⑨ Lens barrel: Trinocular lens barrel, the tilt angle of the lens barrel is 30°, and the adjustment range of the eye width is 48~75mm.
⑩Reflected light illumination: Built-in Köhler lighting 12V100W halogen lamp, light intensity LED indicator, built-in color filter (LBD -IF, ND6, ND25).
⑪Transmitted light illumination: 100W halogen lamp, Abbe long-distance condenser, built-in transmitted light filter (LBD, ND25, ND6).
⑫ Objective lens magnification: 5x, 10x, 20x, 50x, 100x.
⑬ Eyepiece magnification: 10x.
⑭Software measurement system: Tiger3000.

2.Introduction to the working principle of metallographic microscope
The metallurgical microscope relies on the optical system to achieve magnification, and its basic principle is shown in Figure 1. The optical system mainly includes objective lens, eyepiece and some auxiliary optical parts. The group of lenses facing the observed object AB is called the objective lens O1; the group of lenses facing the eye is called the eyepiece O2. The objective and eyepieces of modern microscopes are composed of complex lens systems. The structure of the metallurgical microscope is shown in Figure 2.

The light emitted by the bulb passes through the condenser lens group and the field lens to focus on the aperture diaphragm, and then through the condenser lens to focus on the back focal plane of the objective lens, and finally irradiates the surface of the specimen in parallel through the objective lens. The light reflected from the sample enters the objective lens group and the auxiliary lens, and is turned by the half mirror. It passes through the auxiliary lens and the prism to create an inverted magnified real image of the observed object. The image is magnified by the eyepiece to become the eyepiece The enlarged image that can be seen in the field of view

(1) Aperture stop (AS): used to control the size of the aperture angle of the human beam. It is not used to adjust the brightness. When the aperture diaphragm is adjusted so that the human beam just fills the objective lens, the discrimination ability is the best and the image contrast is good. It should be noted that when replacing the objective lens, the size of the aperture diaphragm should be changed along with the adjustment.
(2) Field diaphragm (FS): used to control the size of the field of view area, reduce the reflected light and glare inside the lens barrel, thereby improving the contrast of the image, usually the field diaphragm should be adjusted to just fill the eyepiece.
The operation steps of OLYMPUS BX51 are introduced as follows:
(1) The basic steps of microscopy system operation.
(a) Choose bright field or dark field observation.
(b) Turn on the power switch.
(c) Turn on the computer and run TIGER3000.
(d) Optical path selection (observed with CCD or with eyes).
(e) Place the sample (adjust the sample with the XY axis).
(f) Choose a suitable objective lens (use a low magnification first).
(g) Focusing.
(h) Adjust the light intensity.
(i) Adjust the eyepiece (the CCD does not need to be adjusted).
(j) Adjust the diopter (the CCD does not need to be adjusted).
(k) Adjust the AS (condenser aperture light analysis) and FS (field diaphragm) (AS and FS should be opened during dark field observation).
(1) Adjust the objective lens and refocus.
(m) Adjust the light intensity.
(n) Make observations.
②Transmission type.
(a) Turn on the power and adjust the light intensity.
(b) Turn on the computer and run TIGER3000.
(c) Adjust to transmission observation.
(d) Press the LBD filter.
(e) Select the optical path.
(f) Place the sample and adjust the XY axis.
(g) Adjust the appropriate objective lens (use a low-magnification objective lens first).
(h) Focus.
(i) Adjust the AS (condenser aperture diaphragm) and FS (field diaphragm).
(j) Readjust the objective lens and focus.
(k) Adjust the light intensity and interference plate.
(l) Make observations.
(2) Use steps of metallographic processing software
① Open the metallographic processing software.
②Select geometric measurement.
③Select the hardware parameter setting.
④Select the corresponding hardware parameters.
⑤ Collect graphics.
⑥Using two-point method and other methods for geometric measurement.
⑦Save the picture.
(3) Precautions for the use of Part V.
①The microscope is a precision instrument, and the operating range should be as light as possible when using it.
②It is strictly forbidden to directly touch the glass part of the microscope lens and the ground surface of the sample with your fingers. If there is dust on the lens, it will
The clarity and resolution of the sound microscope. At this time, you should first use the ear wash ball to blow off the dust and sand, and then use the lens paper or brush to gently
Wipe, so as not to scratch the lens glass when wiping directly, which will affect the use effect.
③The operator’s hands must be washed and dried, and the environment must be kept clean and dry.
④ Be extremely careful when replacing the objective lens and eyepiece to prevent accidental landing.
⑤The sample to be observed must be completely dried with an N2 gun, and carried on the slide for observation.
⑥The relationship between the direction of the coarse adjustment knob and the lifting direction of the stage must be clarified before focusing. Rotate coarse adjustment first during operation
The hand wheel makes the stage slowly descend, and at the same time the eyes are observed through the eyepieces, the field of view changes from dark to bright, continue to rotate the coarse adjustment hand wheel to make
The stage is slowly lowered until a blurred image appears, stop rotating the coarse adjustment handwheel, and use the fine adjustment handwheel until the picture appears.
Until the image is clear.
⑦Be sure to turn off the halogen lamp to the minimum when shutting down.
⑧After the sample is observed, turn off the power of the halogen lamp before leaving.