Viewing small parts in detail is important both during and after assembly. Both microscopes and magnifying lamps can provide the necessary magnification, however they differ in several ways and should be used at different times.
Magnifying Lamps for Soldering or Working with Tools Under Magnification
A magnifying lamp is a combination of a magnifying glass lens surrounded by a lamp with either a weighted base or a bench clamp arm. Different models are available with choices of magnification and brightness levels. Magnifying lamps are relatively inexpensive compared to microscopes making them the better choice for hobbyists or continual use in a production setting.
For soldering, magnifying lamps are a useful tool for working while under magnification, as the working distance (focal length) ranges from 8” to 13”. Working distance is the distance between the lens surface and the workpiece. The most common lighted magnifying lamp comes in 3-diopters, which has a 13” working distance or focal length. A 3-diopter lens magnifies by 1.75X; a 5-diopter lens magnifies by 2.25X but reduces the working distance down to only 8”.
Use a magnifying glass light if you need to assemble parts using hand tools in your workshop or to repair small parts. The light magnifier floods the workpiece with light while simultaneously enlarging your parts.
Microscopes for Inspection and Quality Control
A microscope is most often used when you need to take a closer look at a solder joint for any errors and for quality control. For instance, if you need to closely inspect a Surface Mount (SMT) solder joint, the surface condition of a substrate or miniature component for quality control purposes then a microscope is the best device to use.
Traditional stereo zoom microscopes have a magnification range of 10x-40x and are frequently used for inspection of miniature parts such as electronics. Newer digital microscopes use a digital camera with microscope software attached to a computer monitor.
Digital microscopes allow an image to be captured, have a working distance long enough to work under and operate with the worker in an ergonomically correct working position compared to a traditional stereo zoom microscope.
Both magnifying lamps and microscopes are important tools to have for close inspection of the solder joint after soldering. It ultimately depends on the level of magnification you need, the assembly, and your workspace.