Micro-drilling can be defined as the creation of very small holes 0.5 millimeters or less in a suitable material. This technology has been created and continues to be developed as parts and systems are miniaturized and new products are created, especially in the electronics, medical and industrial process industries. The process differs from conventional drilling not only in the size of the holes, but in the methods used to drill them. Most micro-drilling is done using a technique, where the drill bit is repeatedly applied to the work piece and then pulled back in order to clear debris from the hole.
A good example of a part suitable for this process is a filter for a medical device. The filter consists of a titanium plate with 400 micro-drilled holes. Other applications would be circuit boards for computers, which require very small holes to allow components to be installed. Any sort of product made with lithographic processes or electroplating benefits from this technique, which is capable of drilling holes meeting extreme tolerances for depth, diameter and smoothness.
Micro-drilling work can be done on nearly any sort of material capable of taking a regular drill, since the micro-drill bit is made of either tungsten carbide or cobalt steel. This process works best on flat surfaces in order to prevent the drill from walking across the material as it gains purchase. However, angle drilling is possible with special preparations, including notching the material at the drill site to act as a pilot hole. It is possible to micro-drill plastic materials as long as care is taken to not heat the plastic excessively, which causes it to adhere to the drill and spoil the hole.
As this work is very specialized, micro-drilling quotes should be obtained from a number of different sub-contractors before starting work. These specialty shops should be able to offer evidence of past acceptable work under rigorous conditions. Micro-drilling companies often offer these services as part of a package, taking blank stock, drilling and otherwise preparing it, then shipping it to the manufacturer for final assembly and check out.