Ultrasonic & Megasonic washing and other cleaning techniques seem to have an upper limit in producing cleanliness. Some relevant quotes:
“… washing steps are not able to remove very small particles, such as those having a size of less than 0.5 µm.” [United States Patent 8,182,868 B2, Maxtor Corporation, May 22, 2012]. “
“Some prior systems have tried to minimize particles by cleaning in an aqueous or solvent solution but have not succeeded because the particle reduction plateaus.” [United States Patent 2004/0201926 A1, Seagate Technologies LLC, October 14, 2004]. “
The relationship between encapsulation and cleanliness is well documented. To laminate a component with a layer to contain particles not removable by washing was published as early as 1992 by IBM in its “Technical Disclosure Bulletin”, Vol. 35, Issue 7.
Several patents were filed by HDD manufacturers about immobilizing particulate by encapsulation of mechanical components, for instance, United States Patent 8,182,868 B2, Maxtor Corporation, May 22, 2012.
In order to study and verify the effectiveness of cleanliness by deposition, a laboratory was established. Liquid Particle Counter and relevant necessary equipment were acquired.
VPN® stands for Vacuum Precision Nano-deposition. Nano-deposition here refers to thickness control down to atomic level.
VPN® is the complete answer to thin film deposition; it is adaptable for research applications as well as high volume industrial production. VPN®comprises a series of processes: the thin film deposition itself and all other essential supporting processes specially designed to ensure consistent quality and facilitate process control. VPN® usually adopts Atomic Layer Deposition (ALD), it can also takes on other deposition techniques such as Chemical Vapour Deposition (CVD) or Physical Vapour Deposition (PVD) etc. depending on requirement.
A contamination-free surface is critical in any vacuum deposition process. SOLVE has accumulated extensive experiences in Ultrasonic and Megasonic cleaning which can be applied seamlessly to pre-ALD cleaning.
After years of trials, SOLVE had matured the VPN® process, such process has implemented to encapsulation of components used in a HD Drive to control particulates, achieving excellent cleanliness.
VPN® can also be applied to other applications such as optical lens, fastener for anti-galling, nano-imprint mould, jewelry protective and decorating layer etc.