By Mark Shortt
One of the pioneers in precision manufacturing of parts from difficult-to-machine materials is Insaco, a Quakertown, Pennsylvania-based machine shop that specializes in ceramic materials.
Insaco (www.insaco.com) has been machining, grinding, and polishing a variety of ultra-hard materials to customer-specified requirements since 1947. Besides ceramics, the company’s experience with advanced materials includes sapphire, glass, quartz, composites, carbides, nitrides, and other materials that are neither metallic nor plastic.
“We have the facility and experience to create almost any geometric feature in these difficult-to-process materials,” said Insaco Vice President Scott Mittl, a sales engineer with an interdisciplinary degree in applied science and materials engineering from Lehigh University, in an emailed response. “We also suggest various advanced materials for end use applications, based upon manufacturability and materials properties desired.”
Insaco helps customers address manufacturing needs in critical industries from aerospace and defense to clinical chemistry, medical and life sciences, and semiconductor and compound semiconductor manufacturing. The company’s clients are also active in scientific instrumentation, process manufacturing, oil and gas, metrology, renewable energy, and automotive research and development.
“We fabricate anything from a single rod or washer to very complex geometrical shapes while holding extremely tight dimensional tolerances,” Mittl said. “As a job shop, Insaco will take on quantity requirements from prototype to full series production.”
Insaco operates a lean manufacturing shop that produces custom parts to customer specifications. All part designs are unique to the designer, and apply to situations in which common materials, such as steel or plastic, fail to meet the environmental or process requirements. For these applications, ceramics become the optimal—and sometimes the only—material that can satisfy the requirements.
Mittl said that Insaco’s manufacturing team can make sapphire tubes with polished inside and outside diameters, resulting in optically transparent surfaces on all dimensions. It can polish sapphire to optical figures while holding surface finishes to as low as less than 10 Angstroms.
He added that many applications require diameter size dimensions to +/- 0.0001 inch, with even tighter roundness and cylindricity. The company can create matched ceramic piston/ceramic sleeve sets with gap clearances to less than 0.00004 inch (less than 0.001mm). This gap allows for pumping of various solutions without seals that can wear or degrade during use, he said.
“Over many decades, customers have recognized Insaco as a valuable resource with unique engineering and machining capabilities, allowing us to fabricate everything from simple parts to unusual shapes and forms,” Mittl said. “Our ability to machine is exceeded only by our ability to measure the parts we are machining, which is very critical to meeting customer print requirements.”
Insaco continually reinvests in new production and inspection equipment to ensure its team is using the most up-to-date machine tools. Besides training the company’s machinists on its grinding machines and inspection equipment, Insaco educates its workforce with classes in computer aided design (CAD) and geometric dimensioning and tolerancing (GD&T), Mittl said.
Another Insaco specialty is volume production of sapphire wafers carriers with a tight total thickness variance (TTV) of less than 0.0001 inch, while maintaining a see-through optical finish polish. These requirements allow for successful backside thinning and backside via etching for the compound semiconductor industry, Mittl said.
“We also have the ability to make ceramic quadrupole collars for the RGA (residual gas analysis) and mass spectrometer industries. We can machine to size and locational accuracy on the precision holes to as low as less than 0.00004 inch (0.001mm).”
Although Insaco doesn’t produce the materials it works with, Mittl said its knowledge of the supply chain for advanced materials enables it to acquire the appropriate raw materials efficiently.
“We procure material needed for specific jobs in an oversized hard-fired condition,” he explained. “Not producing the material in-house allows Insaco the freedom to offer designers unbiased guidance on material selection. This guidance is based on the material’s properties, availability, and manufacturability.”
Insaco employs more than 60 team members at its 85,000-square-foot facility in Quakertown. The climate-controlled facility has a class 100 cleanroom and capabilities for laser marking, outside diameter (OD) and inside diameter (ID) grinding, and OD and ID honing and polishing.
The company also offers surface grinding, centerless grinding, rotary ultrasonic grinding, and jig grinding, along with lapping and polishing to MIL 13830 on various optical materials. Robotic machining and inspection are also available, as Insaco looks to increase its use of robotics for high volume production in a lights-out environment, Mittl said.
Precision Ceramic Gearing Solves Contamination Problems
One of the company’s clients, a semiconductor processor, was experiencing contamination problems with metal and plastic gears that were exposed to intense chemical, thermal, and high vacuum conditions. The client was considering using technical ceramics for chemical resistance. However, precision pinion gear teeth must be strong enough to survive load, in addition to being uniform, Mittl pointed out.
Insaco recommended a ceramic material—Yttria blended tetragonal zirconia polycrystal (YTZP)—for its toughness and resistance to chipping. It based its recommendation on the existence of fine features and point stresses in the application of a precision ceramic gear. The fine grain and unique crystal orientation of the YTZP material actually absorb energy to fight fissure or crack propagation, the company said on its website.
Insaco, tapping into decades of experience in machining sapphire and YTZP, was able to provide both materials.
“The precision machining required to generate useful gear profiles in sapphire was challenging, but the result allowed our customer to proceed confidently with technical trials,” Insaco said on its website. “YTZP zirconia, being more robust, may still be the ultimate choice for production, but having the choice to fabricate with either material was the key to successful early trials.”