The Most Essential Tool for Repair Techs

Microscopes are essential tools in the rework and repair department. While there have been many applications for other types of manually operated vision systems, such as illuminated magnifiers and CCTV-based systems, the importance of microscopes has been driven by the ever-shrinking size of electronic components, connections, and assemblies, as well as the spaces between adjacent components.

Microscopes used in this scenario are almost exclusively stereo zoom microscopes, which offer depth perception for the operator and the ability to zoom in for close work or out to check the work relative to the surrounding circuit board topography.

It should be noted that the role of the microscope in rework is not inspection, but a tool under which the operator works; rework is performed while viewing, unlike viewing or inspecting after the task is completed.

Stereo microscopes used for rework are in constant use and require certain features to meet the job's demands. Looking through a microscope for an entire shift can be stressful and strain the neck and back. 

Ergonomics is essential; any microscope can be uncomfortable to use for extended periods, the user bent forward, eyes pressed to the eyepieces, rigidly trying to adjust, focus, and hold a steady position to avoid "black spots" at the edge of the narrow field of vision that result from incorrect eye positioning in the scope. 

Neck aches, stiffness, backaches, eyestrain, and headaches are often the afflictions associated with extended microscope use. Workers need to take frequent breaks to stretch, relieve stiffness, and change position. Uncomfortable workers can't focus properly or deliver quality work.

Pain and discomfort are distracting, and less-than-optimum work quality can result. An ergonomically designed microscope will have an incline or angle so the operator is not looking straight down at the workpiece. We have modified microscopes so that we can move the head with special elbow mechanisms to any angle our operators want and lock it in place. 

It is also crucial that the microscope has independent focus ability on each eyepiece to allow individual operators to adjust the scope to their vision variations and requirements. 

In our own experience, we have found that zoom capability is vital. Operators need to be able to zoom in tightly on a critical area and then back away to view the workpiece at a larger scale. A zoom range from 9X to 40X is desirable; some microscopes include a .5X supplementary lens that reduces the zoom range to 4.5X-20X. 

As for lighting, we prefer fiber-optic, LED, or halogen lighting. They're intense, but close to natural light. Gooseneck arms allow adjustment and repositioning to eliminate glare, which can bounce up into the operator's eyes. 

Our operators often prefer using multiple light sources, such as two halogen lights on the workbench, or a dual-point fiber-optic illuminator with focus-adjusting lenses to inspect critical areas with extreme accuracy. Having two light sources helps the operator eliminate shadows to see every aspect of the workpiece. This gives the operator the ability to "tailor" the illumination by directing the angle and proximity of the light sources. 

As rework advances and the dimensions of electronic assemblies shrink, the microscope will become an increasingly essential tool for successful rework. Ensuring the microscope has the necessary features, flexibility, and ergonomics will ensure quality workmanship from the beginning of the shift to the end.