Manufacturing products for the micro-electronics industry imposes great demands upon production quality, with slight contamination leading to a potential standstill.
Global filtration, separation, and purification specialists such as Parker Domnick Hunter are constantly raising the bar to provide technology to eliminate contaminants such as oil and water from compressed air used in such applications.
Systems incorporating their PNEUDRI Maxi adsorption dryers – available throughout Australia and New Zealand were recently set the challenge of providing optimal standards of compressed air quality for the global Philips electronic group.
"We demand a lot from our machines and this also applies to compressed air", says Gerben Nijman, Technical Service Manager at Philips Enabling Technologies Group.
Precision and quality are more important to Philips in Almelo, Holland, who employs some 550 people. Among other things, Philips manufacture equipment to produce Lithium wafers for assembly into micro-chips.
In this industry one talks in nanometres rather than millimetres.
"In the photo-lithographic machines which we produce, there is a certain x/y composition. This composition is brought about using air bearings, which blow compressed air onto circuit-boards to create an air pocket" Gerben Nijman replied.
"This air pocket is only a few micrometres in size. If dirt particles or humidity from the compressed air were to settle in this area, production would have to be halted, resulting in expensive downtime".
The demands placed upon the quality of the compressed air in the electronics industry and especially in the manufacture of micro-chips are high.
Above all, compressed air must meet with clean room and process air criteria, says Parker Domnick Hunter’s business development manager for Australasia John Davis.
The quality of the compressed air produced by so-called oil-free compressors is often not sufficient to supply air to precise, high performance manufacturing equipment, which may represent millions in terms of investment. In each case compressed air must be treated, he says.
Philips ETG decided to purchase and install a complete compressed air and treatment package. At first Gerben Nijman found it paradox that the compressors being quoted were oil-lubricated in nature, as oil-lubricated compressors would surely add oil droplets to the compressed air?
However, even oil-free compressors take in oil contaminated ambient air and concentrate this up to seven or eight times its original state. Should oil be present at any time in the compressed air the highly sensitive machines used in microchip manufacture would be damaged - or represent a considerable source of contamination.
It is therefore imperative, independent of the method of producing compressed air, to treat it well. The heart of this compressed air treatment consists of a Domnick Hunter PNEUDRI Maxi adsorption dryer, which - together with pre- and post filtration - represents the complete treatment package.
This package enables the user to profit from the economic advantages of an oil-lubricated compressor, even in critical applications.
The contaminated compressed air is at first cleaned by a three-stage filtration system to remove bulk and fine contamination in the form of oil, particles water and pipe-scale.
The remaining humidity in the form of water vapour is not removed by this filtration method so the compressed air enters a heat-regenerated adsorption dryer with dewpoint dependent switching from Domnick Hunter.
Here the air is dried to –40°C. Following the dryer, the last treatment stage consists of an after-filter, to remove any dust which may have been given off by the dryer-bed.
This high-performance compressed air dryer from the PNEUDRI-Maxi range of Parker Domnick Hunter products represents a truly new concept in energy saving, says John Davis.
By combining the proven advantages of adsorption drying with modern, modular design, Parker Domnick Hunter has succeeded in developing a compact and reliable system, capable of meeting all of the demands placed upon it in a compressed air system.
The new compact and electronically controlled PNEUDRI MX and MPX systems available in Australia and New Zealand feature patented modular construction that allows for rapid expansion of systems as needs expand, as well as providing 100 per cent standby drying capacity at a fraction of the cost of larger conventional systems.
With aluminium formed towers typically half the size and weight of traditional twin tower designs- taking up less space and making installation easy, the heatless dryers will deliver air at – 40 deg C pressure dewpoint as standard, in accordance with ISO 8573.1 :2001 class 3.2.1.
When combined with Domnick Hunter’s extensive range of filters, the dryers can achieve air quality class 1.2.1 and 1.1.1. Flow rates of individual units extend from 408 Nm3/h to 2815 Nm3/h.