Although Nor-Cal offers thousands of standard vacuum system components a significant portion of its production involves the design and fabrication of build-to-print items. These include stainless steel chambers, systems & assemblies as well as a variety of modified standard vacuum components.
To support this business segment, and to continue to provide value-added service to our Customers, Nor-Cal maintains strong in-house capabilities in the following areas.
Design, Engineering Services, Materials Selection, Fabrication, Parts Cleaning, Electro-polishing / Surface Treatments, Cleanroom Assembly & Packaging, Helium Leak Check, Quality Assurance
No Customer’s requirement is too small or big, nor too simple or complex. We take pride in our ability to put our know-how in design and manufacturing to use in solving your vacuum system requirements.
Nor-Cal's engineering staff can design custom components from customer specifications, sketches or drawings and oversee production with in-house tooling and equipment. Our customers benefit from the combined experience of our engineers, whose input during the design phase often results in cost savings during production and a superior product. We have complete prototype machining capabilities along with the ability to perform pressure, conductance and thermal characterization as well as software and electronic development and testing.
Some examples of products we have designed for customers include vacuum chambers with or without load locks, manipulators and frames; custom isolation valves; custom pressure control valves and controllers; application specific foreline traps; custom heaters; custom weldments and flanges; and subassemblies comprised of various proprietary and purchased components.
Nor-Cal's engineering department uses the latest versions of AutoCad drafting, Inventor & SolidWorks 3D modeling, and Cosmos & Algor FEA software packages. You may e-mail drawings direct to our engineering department at firstname.lastname@example.org. Acceptable file formats are DXF, DWG, and IGES, SAT and STEP.
As an indication of commitment to quality and customer satisfaction, Nor-Cal's engineering staff thoroughly reviews each custom vacuum component for manufacturability before the production process begins. This value engineering is provided at no cost to our customers in order to provide an appropriately toleranced, cost-effective product. Questions regarding design, specifications and testing are directed back to the customer for final approval.
For our customers who do not have drafting personnel available and require a complex assembly, we can provide complete CAD drawings for approval upon receipt of order. Nor-Cal's engineering department uses the latest versions of AutoCad drafting, Inventor & SolidWorks 3D modeling, and Cosmos & Algor FEA software packages. You may e-mail drawings direct to our engineering department at email@example.com. Acceptable file formats are DXF, DWG, and IGES, SAT and STEP.
Nor-Cal Products uses only the highest grade materials for the manufacturing of vacuum components. Vapor pressure, corrosion resistance and permeability are important considerations taken into account during the material selection process.
We start with select grade 304 stainless steel tubing, spheres or roll-ups to fabricate the vacuum component. If required, parts made of 304L, 316, 316L or 316LN can be supplied. Normally our standard material is in the low carbon range for 304. Flanges and baseplates are often made from 304 that has been specially treated to remove impurities inherent in 300 series steels.
Special UHV-flanges 4 ½” OD and smaller can be made from 304 electroslag remelt (ESR) bar stock. ESR is a refining process that produces stainless steel with higher purity, fewer inclusions and more uniform grain structure to eliminate microscopic leak paths.
Our standard flange material is certified to meet ASTM A-240 and has less than 0.01% sulfur to prevent sulfur stringers. Grain size is 3 to 6 per ASTM E-112. Maximum inclusion size is 2.5 per ASTM E-45. As specials, 304L and 316L material can be supplied in roll-forged rings.
Machining procedures are consistent with proper UHV practices. Machine coolant is sulfur free to reduce outgassing of the finished part. All Nor-Cal components are designed to minimize entrapments, which may cause virtual leaks under high vacuum conditions. State-of-the-art CNC machining equipment is available to produce parts with consistently high quality.
Most valve and trap body ports and weld fittings are die-formed using the pulled-port method. A ball is pulled through a smaller opening resulting in a crevice-free, smooth, tapered opening. This eliminates sharp inside corners that can entrap contaminants, and allows faster pumpdown and lower outgassing.
GTAW fusion welding is used exclusively for a vacuum-tight metal bond. Purging with an inert gas reduces or eliminates oxygen entrainment and carbide precipitation, which also cause outgassing. Whenever possible, welds are made on the inside or are full penetration to eliminate entrapments and virtual leaks. Orbital welders are also available for precise weld penetration. Welding procedures are based on ASME Section IX with Weld Procedure Specifications on file. Individual welders are certified to Procedure Qualification Records by a third party lab.
All parts are first cleaned with a biodegradable detergent to remove machine lubricants. The stainless steel component is then passivated in a light acid solution to remove weld scale.
Chemical cleaning is typically used for production parts such as valve bodies or "process critical" parts fabricated for semiconductor equipment manufacturers.
Finally, all parts are washed and rinsed in >10 MOhm deionized water and dried with clean, dry air filtered to .05 micron. Cleaned parts are immediately packaged and sealed in clean room bags which meets or exceeds cleanliness requirements of IEST-STD CC 1246D Level 100. Special cleaning recipes can be provided to our customer's specifications.
Electro-polishing / Surface Treatments
Electropolishing is by far the most desirable cleaning process for stainless steel vacuum components. This electrochemical process benefits the finished part in a number of ways simultaneously. Deburring, passivation and stress relieving are achieved while the machine produced surface roughness is eroded.
Electropolishing attacks the microscopic "peaks" of the surface more rapidly than the "valleys", thereby maintaining critical dimensions while improving surface finishes. Normally .0003 to .0004 inch is removed to lower the micro-finish from 32 to 8 RMS. Electropolishing results in a 90% friction decrease over a similar microfinish achieved mechanically, while surface area is reduced by a similar amount. This is most important for vacuum chambers because it produces faster pumpdown and higher conductance.
In addition to the improved mechanical properties of the surface, iron is removed electrochemically. This leaves the surface rich in chromium and nickel, which have extremely low vapor pressures. The result is the lowest outgassing rates possible from stainless steel. Our electropolish process is rated to UHP grade per SEMI F-19.
Nor-Cal also offers tumbling and bead blasting of vacuum components in-house. Tumbling in ceramic media deburrs components, such as weld fittings, while providing a uniform finish. Glass shot cleans, hones, polishes and peens while removing scale. Some customers request bead blast on exterior surfaces with electropolish on the interior.
Cleanroom Assembly & Packaging
Nor-Cal has two clean rooms for assembly and packaging of semiconductor valves, UHV systems and components. Pressure control and isolation valves as well as sample transfer and manipulation devices are assembled, leak checked, tested and packaged in a 3000 square foot Class 1000 clean room, which is subdivided into five areas for assembly, inventory, leak check and other testing. This allows greater visibility, better inventory control and compresses assembly lead times. System integration, chamber final assembly, testing and packaging may also be conducted in a Class 1000 clean room or at a Class 100 workstation. Clean parts are packaged and sealed in clean room bags which meets or exceeds cleanliness requirements of IEST-STD CC 1246D Level 100.
Helium Leak Check
Every weld and vacuum assembly is leak checked with a He-leak detector to ensure a leak rate of 1x10-9 atm.cc/sec He, or less, conforming to ASTM E498. Our chamber qualification test bench can be used on components requiring lower leak rates. It was developed for customers who request residual gas analyzer (RGA) scans of their chambers after a 24 hour vacuum bake. The test bench contains vacuum pumps, gauges, RGA, quartz heaters, nitrogen back fill and a leak detector. Once water and other background are eliminated by the 150C bakeout we can provide the customer with customized scans to detect the slightest contamination in the chamber. Whatever the sensitivity of our customer's application, we can guarantee that contaminants will be within acceptable limits.
Nor-Cal Products is an ISO 9001-2008 Certified company, that has also received SEMATECH SSQA Preferred Supplier status from two large semiconductor equipment manufacturers. Our Quality Management System also supports MIL-Q-9858 Quality Program Requirements and ANSI/ASQC C1 General Requirements for Quality Program.
Ongoing efforts are made to control and improve manufacturing processes. Periodic defect analysis results in process improvements with narrower acceptable limits on subsequent production runs.
Our calibration procedures meet MIL STD 45662A and our QA sampling plan meets MIL STD 105E. A coordinate measuring machine (CMM) is used for in-process and final mechanical inspections of vacuum chambers and other complex or close tolerance parts. CMM printouts of chamber final inspections can be furnished upon request.
To get more information about Nor-Cal’s Products' Design & Manufacturing Expertise, or to obtain a quote, please complete the online RFQ Request form.