- Our handling equipment only requires electronic power supply and (in case of overhead handling) underpressure/vacuum.
- By avoiding any surface contact the sensitive substrates are not damaged by microscratches, micro-cracks or contamination.
- Because no additional air is injected, our systems cause no disturbance of the laminar air-flow within a clean-room environment.
- In comparison to "traditional air-bearings" the operating costs are reduced, due to the avoidance of air-cleaning and -supply.
- There is only a small maintainance effort.
- The control interface allows a very good and simple system monitoring.
- Our technology is compatible with any kind of process gas.
- Thin and flexible substrates can be flattened during the handling process in order to reach a high surface evenness.
- Topside handling of textured or coated surfaces is possible without any contact.
- Process and machine design becomes more flexible due to these mentioned handling possibilities.
For (contactless) topside handling a combination of underpessure and ultrasound is used. While the underpressure pulls the substrate upwards toward the tool surface the repelling effect of the ultrasound assures the gap between tool and substrate. Hence any contact between tool surface and substrate can be avoided.
Mainly the substrate should be "flat", which means the thickness should be a lot smaller than length or width or diameter. In case the shape of the substrate is bended (purposley and rigid), this bending should be in a repeated, defined way.
Parts/substrates which are not too rigid can be flattened by underpressure nozzles, which are integrated in the sonotrode. This effect can be used not only for topside handling (where an underpressure is always necessary), but also for bottom side handling. The flattening effect can for example compensate substrate concavity during inspection.
You are very welcome to send sample material to us, so we can test on short notice whether the ultrasound bearing is usable in combination with your material. Of course you are also heartly invited to visit us, so you can personally have a look at the different handling solutions we can provide.
No, the ultrasonic bearing is created by a fluiddynamic effect. In the contrary to ultrasonic cleaning (where the vibration energy is converted to cavitation), for the ultrasonic bearing the environmental gas is squeezed by the cyclic compression and decompression. So between the gripper and the substrate a condensed air-film is created. The vibration energy is used for the compression of the gas and is not transferred to the substrate. So there is a rather high damping effect of the gas film. Most substrates simply can not follow vibration movements of more than 20kHz due to their inertness. Only on very light and thin substrates mild vibrations could be measured.
For the angular orientation of a pre-aligned wafer it is possible to achieve an angular precision of <0,1° using appropriate (tactile) mechanisms. The precision of three-dimensional substrate placement is mainly affected by the tolerances of the involved axes and mechanical end-stops.
Typically the gap induced by the ultrasonic air bearing is 50µm - 150µm. For overhead handling or for very light substrates the gap might become bigger.
Yes, because the substrates float on a densed air-film, which is created by the cyclic compression of the environmental gas (air). In the gap between the handling surface and the substrate an overpressure is formed, which carries the substrate.
If topside handling is required, an additional vacuum/underpressure hinders the substrate from falling down whereas the ultrasonic force still is repelling the substrate from touching the tool.
Yes, there are plenty degrees of freedom for the design of the handling tool. The sonotrodes (ultrasonic moving surfaces) can be adapeted in length, width or thickness. Also bended sonotrodes are possible e.g. for medical lenses.
Please refer to question 5.
For very small parts which are handled from the topside there is a self-centering effect at the tip of the gripper. Using this effect it is possible to handle substrates up to a size of 12x12mm completely touchless - even without any side contact.
No, because the ultrasonic energy used in the bearing technology is so small that the available distance or mounted housing reduce the acoustic waves, so no health risk is caused.
In principle it is possible to create handling solutions up to ISO 1. Typically the ultrasonic bearing technology is used in clean-room classes from ISO 5 or better.
Of course all our systems meet the requirements of the CE norm. If required, for certifications according to UL, CCC, IEC60601 or ISO13485 we can provide the necessary documentation. A certification of a product according to one of these special norms by ZS-Handling needs to be coordinated in the particular case.