Product category:
PCB Assembly Equipment and Tools
News Release from: Guyson International | Subject: Guyson Supercleaner
Edited by the Electronicstalk Editorial
Team on 24 August 2007
Hard disc cleaning technology improves
reliability
Guyson Supercleaner can remove sub-micro contamination from disk drive components.
The hard disk industry has just celebrated its 50th anniversary and now it is almost impossible to imagine a world without hard drives Not just used for computers, they are now installed in many every day consumer products such as: camcorders, MP3 players and digital video recorders
This article was originally published on Electronicstalk on 26 Mar 2001 at 8.00am (UK)
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Guyson Supercleaner high volume, high-quality aqueous precision cleaning systems have been designed to meet the rigorous quality standards laid down by the International Disk Drive Equipment and Materials Association (IDEMA).
These standards include the removal of sub-micro contamination from disk drive components.
This with the ever higher storage densities involved means that such high levels of cleanliness quality are proving critical to the performance success of the disk drives.
Aqueous washing of precision disc drive components has been the industry standard for the last ten years; therefore, the cleaning process is well established and normally includes an ultrasonic immersion cleaning tank designed for use with water-based cleaning solutions followed by deionised water rinsing and with hot air and vacuum drying.
This type of multi-stage cleaning process is fully automated to ensure total control of all critical process parameters.
All Guyson Supercleaners have to pass exhaustive testing to ensure continuous running for 23 out of 24 hours a day - one hour is set aside for machine clean down.
This aqueous precision cleaning system will remove organic residues down to ppb (parts per billion) levels and particulate contamination to 0.1 microns from computer hard disk drive (HDD) components.
To achieve these extreme standards of cleanliness, the Supercleaner provides a multi-stage aqueous wash and high purity deionised water rinse process using high frequency ultrasonics selectable at 35, 70, 130 and 200kHz, and a high throughput in-line tunnel type hot air dryer.
The original operating frequency of 40kHz is now considered to be too low for sub micron work, as it results in a degree of cavitation or resonance which may cause damage to sensitive components such as GMR heads.
Effective removal of sub micron particles at 40kHz has also been questioned.
It can be proved mathematically that particles smaller than 0.5um require frequencies of greater than 100kHz to dislodge them.
Whilst some laboratory scale trials claim improved sub micron particle removal at higher frequencies, the practical difficulty is to identify a single frequency which will remove a wide range of particles, say 0.5 to 50um, which would typify production conditions.
Therefore new Guyson microprocessor controlled Primewave generators have been developed to provide switchable frequencies and power levels 70 or 130kHz with frequency sweep and fully adjustable power output (Watts), all programmable within a single cleaning or rinsing cycle.
Whilst it is essential to remove contamination both particulate and soluble from a batch of parts, it is just as important to maintain the cleaning and rinse tanks at a controlled level of cleanliness compatible with preset component and water cleanliness standards.
Guyson Supercleaner wet tanks are crevice free, full 30mm radius corner construction with four-sided flat weir overflow.
The 316L stainless steel is electro polished with chrome plated ultrasonic tank base to eliminate sub-micron entrapment and the possibility of secondary particulate generation due to cavitation erosion.
Filtration systems are sized to allow the total tank volume to be filtered down to 0.1um at high flow rates equivalent to the tank volume every two minutes.
A specially designed sparge pipe return determines the most effective flow characteristics to eliminate liquid dead spots.
All pipework is polypropylene with IR welded joints to ensure the highest chemical compatibility and avoids crevices.
Vertical agitation, typically 50mm x 30 strokes/minute of batch load parts during the cleaning cycle, provides improved flushing of the cleaning and rinse solutions.
A typical Guyson eight-stage Class 10 cleaning system will process components with tanks one and two pre-washing and rinsing with Primewave 35/70kHz or 70/130kHz ultrasonics and micro filtration.
Tanks three, four, five and six comprise the final rinse with cascade rinsing also including Primewave 70/130kHz and 130/200kHz ultrasonics and micro filtration.
Stage seven is a three-stage hot air tunnel dryer, double basket capacity with HEPA filtration and dynamic air flow control, perfect for high throughput on robust mechanical components.
A variation is available with double hot air dryer and vacuum dry which is more suited to delicate components or with difficult to dry blind holes.
The whole process is fully automated using up to three Autotrans two-axis work transporters.
The transporter heads are cantilever-mounted, include servo type motors and are fully programmable with intelligent automatic program selection feature.
Particular attention has been paid to mechanical design for Class 10 cleanroom use.
To complete the Supercleaner specification a windows PC based Scada system monitors all critical process parameters such as temperature, flow rates and water quality.
These are displayed in spreadsheet format and may be recorded for batch traceability purposes. Request a free brochure from Guyson International ...
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