Aluminium is produced with a heavy mill scale and rough (porous) oxide layer— a surface not well suited for vacuum, because it absorbs water vapor and other contaminants. After removing this rough layer PM cleans all metal surfaces before, during and upon completing the fabrication process. PM’s advanced vacuum surface passivation process replaces thick porous oxide layers with a quality thin and dense oxide surface. PM’s proprietary specification establishes a standard for the creation of dense oxide surface passivation. Treating aluminium in this manner effectively reduces surface area, contamination and desorption.
Advanced Vacuum Welding
Even to experienced welders, the welding of aluminium to vacuum standards is a challenge many are not capable of achieving. The welding process can introduce porous oxides that impede hermitic welding. In other industries these welds can meet mechanical standards, but when tested to vacuum helium leak standards are considered inadequate. PM-PRECISION’s aluminium vacuum welds are quite distinctive from conventional aluminium welds. They are more continuous, have a ‘glassy’ surface and minimized area. PM’s welding processes reduces internal and external oxide inclusions, effectively eliminating leak paths or virtual leak pores—essential to good vacuum performance. Typically PM’s processes produces a smaller heat affected zone, which leads to less surface haze and contamination.
PM-PRECISION delivers all standard aluminium demountable vacuum flanges and fittings. These flanges are welded to an aluminium vacuum chamber giving access its interior. ISO quick-release and clamped / bolted style O-ring sealed aluminium vacuum flanges are the most common standard high vacuum fittings. To achieve ultrahigh vacuum levels (UHV), metal seals are required, but aluminium is soft and unable to crush copper or nickel gaskets.
Advanced Machining Capability
The machinability of aluminium is legendary. PM-PRECISION has invested in a ‘state of the art’ manufacturing facility that supports small to very large scale, single and multiple unit quantity, aluminium vacuum chamber fabrication. The bigger the chamber; the more economical aluminium can be. In addition to chambers, PM-PRECISION can also manufacture internal components, ensuring that an entire assembly is produced on time and to strict vacuum standards. When PM manufactures internal components its easier to keep focus on the end goal, the vacuum system’s ultimate performance, ensuring that the system will perform as designed.
Vacuum System Test and Qualification
PM’s vacuum chambers are fully leak tested and vacuum qualified. With clean assembly and test facilities PM-PRECISION can provide complete bake-out and residual gas analysis (RGA), vacuum leak-up, reverse pressurization and other qualification procedures. PM has multiple helium leak-test stations to maintain a high through-put. PM also offers clean assembly for internal vacuum components and advanced systems. This saves you time and ensures that a chamber performs as designed. A chamber is not complete until it meets the PM-PRECISION minimum vacuum leak rate standard of 1×10-9 Torr liter/sec. PM-PRECISION can meet higher vacuum test standards if required.
PM-PRECISION’s aluminium vacuum chambers offer extraordinary UHV performance. Surface treatment, advanced welding processes, and metal-sealed flange technologies have made this possible. The impact of UHV environments for contamination-free manufacturing processing has yet to be determined in a quantitative fashion. Current studies, however, indicate that they will be essential components of semiconductor materials processing and control and key aspects of 300-mm processing systems