Micro Assembly Applications

This is the era of miniaturization the trend that was started a decade back have now completely overtaken a variety of consumer appliances. This demand for very small electronic as well as electro optical components is leading to an upsurge in demand for the small-scale servo actuators needed in micro assembly applications.

The micro gear as used in a Micro Harmonic Drive comes with the advantage of zero backlash. The micro gears have been successfully implemented in a wide variety of miniaturized servo actuators. The use of the micro gears along with the provision of zero backlash also offers excellent repeatability and a long operating life.

Coming to the set up of the micro gears, the total set of the gear component is mounted inside a gearbox. It is on the pre-loaded ball bearings where the output shaft is mounted. The gearbox sometimes is coupled directly to a micro-motor. Another option is to have an input shaft, for the motor to be mounted off-axis. As can be seen from the image a hollow shaft that has an inner diameter of approximately 1 mm is allowed to pass along the gear box's central axis of rotation.

Harmonic Drives

Advantage of using Micro gears
The use of Micro gears in Micro assembly applications offers numerous advantages. Some of which are listed below.

Zero backlash : Micro gears though have miniature dimensions yet they display no backlash.
Excellent repeatability : Micro gears offers precise positioning. As the zero backlash of the Micro Harmonic Drive offers repeatability that comes in the range of a few seconds of an arc. This helps to carry out positioning tasks with ultra precise accuracy.
Long operating life : The micro-gearboxes have ideally an operating life of around 2500 hours. Some times it is seen that these micro gears display a longer life than the application where it is put to use.
Withstand extreme environmental conditions : This is made possible by use of high quality materials like stainless steel or high-alloy steels for all the parts of gearbox housing, shafts etc.
Compact Design
High efficiency : This results in optimal utilization of power.

Examples of Micro Assembly Applications
Rotary Bond Tools : One of the primary application areas for micro assembly equipment using micro gears is in the vast and sophisticated electronics industry. A very popular example can be given of the Die attach machines used for assembling of chips in protective package. The Die attach machine incorporates a Rotary Bond Tool for positioning of the chips with very high accuracy and at desired angle of the rotation. At the heart of such Rotary Bond Tool lies micro gear enabled harmonic drive.

Micro-manipulator : There are many tasks performed by micro assembly that requires movements with the freedom of three degrees. For such assignments a Micro gear enabled Micro- manipulator is applied. This micro manipulator machine offers many advantages like easy control, ultra precise accuracy etc. The following image shows a Micro gear enabled micro-manipulator.