Little Things Factory produces microstructures (such as channels and connecting thru-holes) using both wet chemical and mechanical processes. It employs hydrogen fluoride (HF) for the etching of glass and quartz, potassium hydroxide (KOH) for the etching of silicon as well as ultrasonic drilling, sandblasting and diamond drilling of glass, quartz and Si. This permits the production of thru-holes and blind holes as well as cavities and trenches.
This isotropic etching process is the preferred choice of process when producing flat cavities in glass and quartz. Depending on the depth of the etching, optical-quality cavities can be formed. The depth of the etching is approximately the same as the lateral width of the etching.
This etching process produces cavities and thru-holes in crystalline silicon. If Si <100> Si is used structures with an angle of less than 54.74° can be created.
Ultrasonic drilling of glass, quartz and Si can be used to produce vertical structures (preferably thru-holes) with dimensions from approx. 500 µm.
This especially inexpensive process can be used to produce cavities and thru-holes of almost unlimited geometrical shapes by means of abrasive structuring. Because of the lithographic nature of the process the geometric tolerances of the structures is <= 25 µm.
This individual drilling process is characterized by extremely precise geometric tolerances for vertical thru-holes in glass, quartz and Si. The location tolerance of these drillings to the edge of the wafer is the best possible available for mechanical processes and amounts to less than 25 µm.