Building smaller things that can do the job of bigger ones has always made sense, but progress was hardly noticeable before the late 20th century. Lasers and electronics changed everything. Now we are talking about building machines too small for the naked eye.
The term “micropart” usually crops up in the context of medical and electronic devices. Modern capacitors resistors and chips qualify, as do the miniature sockets, clips and pins that hold everything together.
Small objects present the same manufacturing and operational challenges as big ones. They still need the many proven treatments we have for macro-products. But applying modern surface treatments like electroplating or anodising to something you can barely grip with tweezers requires some expertise.
The Benefits of Surface Treatments for the Micropart Industry
Durability and corrosion resistance are often even more important for smaller components – because they are harder to access, service or replace (and harder to find when you drop them on the floor). That’s even truer when they are part of a medical implant.
In some cases we can substitute more expensive materials like rhodium, platinum and gold. In others there is no substitute for the qualities we can impart with proven technologies like electroplating.
Size precision is critical for small items but a lot harder to adjust by conventional milling. Plating and anodising provide opportunities to tweak the dimensions of small items without a complete overhaul of the supply line.
The electrical properties of small components are often more important. Again, we have established techniques that can modify this. Our ability to apply them is what allows miniaturisation to make progress.
While there are some standard approaches, treatments for microparts are less off-the-peg than for larger products. It is important for manufacturers to work with a finishing specialist in the prototyping phase. Even large items sometimes need design modifications to facilitate successful surface applications.
Two of the most common micro-scale treatments for surfaces are Spouted Bed Electrode (SBE) and selective plating.
SBE provides a continuous flow of the plating solution (usually gold, copper or nickel) through a chamber designed to promote uniform coverage (see one here https://www.technic.com/equipment/process/electroplating).
High-precision selective plating is a means to enhance or refurbish targeted areas and is usually a mobile device. It is possible to apply very precise depths over very precise areas with this equipment.