Microscope for Soldering and Repair Work
A suitable stereoscopic microscope is not only able to simplify the operation, but can also make some operations possible that cannot even be carried out without it. Considering the fact that small chips have an output step of 0.4 mm and a pin diameter of 0.3 mm, the need for a modern optical magnification device for working with such objects is obvious.
So what should a microscope for electronic repairs look like?
The first thing most experts pay attention to is the working distance between the object and the lower edge of the microscope objective. For example, the Altami CM0745 microscope has a working distance of 118 mm, without the use of additional attachment lenses. This is not a small distance, but to make the work of a soldering specialist easier, a bigger distance is usually required. We could obtain a working distance of 195 mm, which is suitable for most daily work, by mounting a 0.5X demagnification lens on the microscope objective.
It should be kept in mind that we are not only increasing the working distance by using demagnification lenses, but also the visible field. That is why, in some cases, when it is necessary to entirely cover a large-sized system board, a 0.35X demagnification lens should be used so that the diameter of the visible field on the object of study reaches 89 mm. Of course, such a lens requires an even greater working distance (i.e. 275 mm). Therefore, it would be better in this case to install the optical head on a higher mount pillar.
For example, the most popular is the CM-U1 mount pillar with DG76 base, as can be seen in the above figure. However, in addition to this type, Altami offers its customers three more types of mount pillars. In addition, each mount pillar can either be mounted on a heavy base or on a clamp.
The next important thing in choosing a device is the correct lighting. If the work is to be performed at a working distance of between 50 mm and 250 mm, a circular LED light with brightness control as shown in the above photo is a good solution.Eight light-emitting diodes, each with a power of 1 watt, give a bright and shadow-free uniform illumination of the entire surface of the object with cold white light. This increases the image contrast while illuminating dark objects. This LED light is especially convenient when a stereoscope is installed on the mount pillar. In addition, the familiar problem for many users of “blinking” of reflecting light objects can be solved by fitting the light with the special polarization set, preventing glare.
If the working distance of the microscope is less than 50 mm or more than 200-250 mm, it is more convenient to use a double-wire LED light with a holder fitted to the mount pillar or to the table as shown on the photo below. The light source consists of two light-emitting diodes, located at the ends of two adjustable flexible necks. These necks will hold their shape once adjusted, making it possible for the lights to be adjusted in such a way that the light beams properly illuminate the object from both sides.
However, keep in mind that the most affordable illumination method is an inclined illuminator integrated into the microscope holder, which is present in table models such as CM-2, CM-4, CM-6, CM-14, CM-17 and CM-19.
You can familiarize yourself with the technical characteristics of the above table models and other additional components of the stereomicroscopes in the brochure.
Finally, the last aspect which should be mentioned in this article, is equipping the microscope with a digital camera that can be connected to a PC.
A digital camera can be useful when it is necessary to save photos of studied objects. For example it can be used to record the defects of a faulty apparatus during inspection to explain the repair requirements to a customer.
The software included in the supply package also makes it possible to conduct linear measurements of studied objects directly on your PC monitor. In addition, an essential object-micrometer needed for software calibration is included in the supply package. Cameras with a USB 2.0 interface and a resolution of 3 or 5 megapixels are sufficient for the task.
If the soldering process is intended to be displayed on the monitor to prevent visual fatigue caused by constant looking through the microscopic eyepiece, the camera with USB 3.0 should be selected. The framing rate of USB 2.0 is too low and the video will be “lagging”, i.e. it will be translated with delays. Cameras of the U3CMOS series proved themselves to be excellent for live image translation; their supply package includes a program for image saving and processing and also a program to conduct measurements.
Alternatively, there is another way to get a video image without connecting the camera to a PC – it consists of installing a special camera with a monitor, resulting in a reduction of workspace.
In this article, we only detailed the main aspects which should be considered when choosing a stereomicroscope for soldering and repair work. More detailed information regarding Altami stereoscopic microscopes package options may be obtained by exploring the brochure or by contacting our managers send a request.