Of White Knights and Virgins
Unfathomable Numbers, a White Knight and a Virgin
A provocative title, yes, but it’s not merely intended to entice you into reading on. There’s a strong commonality connecting these three references that is, in fact, more interesting than the superficial imagery they evoke.
This is a story about creating silicon microchips, parts per trillion and PTFE (polytetrafluoroethylene, the generic term for Teflon®). Okay, so the heading’s summoning visuals may ring more interesting, but let’s move on.
It’s a Family Affair
In 1988, John Simmons borrowed $7000 from a family friend. John had a vision and this was the first step toward its manifestation. The loaned money went to purchase a used Bridgeport mill, which was then stationed in his parents’ garage in a suburb of Salt Lake City, Utah. John, his brothers Tom and David, and occasionally their father, Jack, subcontracted various parts for local businesses – mainly plastic and fluoropolymer components for the semiconductor industry, and for the medical and robotics industries.
Within a couple of years they moved the operation out of the garage and into a small shop, forming A&J Machine. The machine shop continued to grow. “We bought our first CNC machining center, a used Haas VF-2 (serial #1775), from Al Stefani of Stefco Racing. Al was an old motorcycle riding buddy of Gene Haas. We still have the same machine working in this present shop,” reminisced John.
It’s interesting to note that this specific machine was the first CNC for both Stefco and A&J Machine. “Perhaps there’s another fledgling shop looking to purchase its first machining center. There’s plenty of life left in this one,” John adds coyly. “We might consider selling it.”
In the early 1990s, John and brother Tom started developing their own products. They had a customer in the Salt Lake City area who was building high-purity pumps for siphoning acids during the production of microchips in the semiconductor industry. Word of mouth had it that the company was getting a load of customer complaints regarding the pumps’ reliability and the lack of service. John and Tom were inspired – and confident they could build a better pump. They spent the next three years in R&D, absorbing all they could about the requirements of the semiconductor acid pumping business. They developed and unveiled their first pump at Semicon West 1995 in San Francisco, an annual industry trade show. The brothers had done their homework fastidiously, and the pumps were a standout hit. White Knight Fluid Handling, Inc. was conceived.
At that time, real estate costs in Salt Lake City had skyrocketed. “We recognized this would constitute an additional complication to building a company there,” says John. “I had spent some time in Michigan, showing our patents (the pumps are presently protected by seven patents, with two more pending) to companies and discussing licensing them on our technology. I fell in love with the state and the idea that I could live in a rural setting, yet be close enough to the ‘big city’ for our manufacturing needs. With property values at nearly half what they were in Salt Lake, the decision to move wasn’t that difficult,” he adds.
The entire Simmons family now lives and works in Michigan, including the youngest brother, David, who is fluent in Japanese and handles all Asian distribution. Their one sister, Careen, will also join the company upon her return from a two-year church mission in Italy.
The Simmons family bought and totally refurbished the present home of White Knight in Hemlock, Michigan, an impressively designed and organized building, filled with the most contemporary gadgets (i.e., computers and other business electronics). Their reasoning for keeping electronically and mechanically up to date is simple: when customers visit, seeing cutting-edge technology makes them comfortable doing business. When your customer list includes Intel, Motorola, Texas Instruments, IBM, AMD, National Semiconductor, Fairchild Semiconductor and Philips Semiconductor – to name but a few – this is indisputable, pragmatic logic.
White Knight’s pumps are used worldwide, almost exclusively for the semiconductor industry. The company’s claim to fame and secret to success is that their pumps test considerably better than any other pump on the planet with regard to metal contamination when acids are drawn through them.
Most of us are aware that you can short out the wiring in your house by placing a metal object between two wires. Now imagine this on a microscopic scale. Today, the standard line width of circuitry on a microchip is 0.15 micron (a micron being one millionth of a meter or about 0.000039 inch). What that means is that approximately 526 microscopic circuit lines could fit side by side on a human hair. In this environment, where layers of material are only several atoms thick, any microscopic metal that ends up in the chemistry during wet etching or cleaning (the steps that involve pumps and acid) could potentially short out the microchip.
Obviously, metal contamination is not good in the microchip industry. The standard of measurement for contamination when testing pumps is in parts per trillion (unfathomable number example: a trillion seconds is nearly 32,000 years). It’s not uncommon for White Knight pumps to test in the single digits in parts per trillion – and never more than in the low double digits.
The Knight Way or the Wrong Way
Presently, there are only two methods of achieving this extreme level of pump fluid purity. First, make a pump totally devoid of any metal and other contaminants, and second, assemble it in a clean room (Class 100). White Knight has accomplished both, the former being the difficult part. They have been able to create the world’s first pump containing nothing but Teflon – no metal whatsoever.
Others claim to have succeeded at the same thing, but they’ve all been exposed.
Competitors make pumps from Teflon, but fasten them together with nuts, bolts and screws. Revealing these shortcomings was simple – the pumps confessed on their own. The molecular structures of the acids (phosphoric, sulfuric, hydrofluoric and others) used during the wet etching process are so minute that they permeate plastics, passing through in a vaporous form. To complicate things further, the industry then uses these acids at temperatures up to 410 degrees Fahrenheit (basically the temperature of French-fry oil), and if there’s metal anywhere in the pump the acid will attack it, dragging pieces back into the liquid, where it ends up as a short in a microchip.
Too Soft for Comfort
The formidable challenge with creating a pump totally of Teflon is the softness of the material. It’s just slightly harder than bar soap, making it tough to hold tolerances (which are checked daily). “We hold our tolerances to plus or minus 0.002 inch. That doesn’t sound like much, but it’s not the equipment’s fault. Teflon just doesn’t hold its shape well, especially when you remove more than 50 percent of the material for fluid cavities and liquid flows,” commented Tom.
Due to Teflon’s very high coefficient of thermal expansion, high-speed machining isn’t an option, because the heat generated would cause even more interference with holding tolerances. Therefore, coolants aren’t required, which is favorable, because they would only contaminate this very porous material.
“Most industry experts adhered to the belief that Teflon was too soft to be threaded together, and they were afraid that it would lead to acid leaks and, no doubt, serious injury,” John told us. He adds, “We figured out that with a CNC machine it would be feasible to synchronize the starting points of the inside and outside of a thread hob and make a combination cap/plug, screw it together and have twice as many threads as anybody else’s pump.” Both John and Tom share the credit for this breakthrough.
Several special tools are required to create these threads (for obvious reasons, the Simmonses are reluctant to reveal too many specifics regarding their special tool designs). The first tool is used to trepan a groove 0.07" wide and 0.75" deep. This is cut with a peck drill cycle on a Haas mill. The next tool is a custom-designed tap/die that has both internal and external threads. This threads both sides of the aforementioned groove using a rigid tap cycle. The real difficulty the Simmonses had to overcome was that by the nature of the tap/die there isn’t much room for chip clearance. The tool must be programmed to tap part way down, retract to clear the chips, re-tap further, retract again, and so on for at least four passes to reach the bottom. “This capability was very important when we were looking for our first machining center,” explains Tom. “Haas was the only tool manufacturer to guarantee that we could repeat a rigid tap without fear of cross threading.”
Most of the other tools used are standard, such as endmills, drills, et cetera – the same as for cutting aluminum, except the tools last nearly forever. The majority of tools scrapped are due to nicks resulting from being bumped while putting them back in the tool cart, not from wear. The Simmonses also use a number of Haas rotary tables in order to machine four sides of a pump in one setup, which is a huge time and money saver. Presently, White Knight owns six Haas machining centers to satisfy all their machining requirements – a VF-1, VF-2, three VF-OEs and a VF-3.
“The semiconductor industry forces us to use only virgin Teflon: Teflon that hasn’t been used before, not recycled,” clarifies John. Pure virgin Teflon or PTFE, which hasn’t been cured or baked, comes in the form of a light fluffy powder. It’s only after a very labor-intensive procedure that virgin Teflon is structured into the 7 x 7 x 7 inch blanks used by White Knight to mill the principal pump components. It’s a specific and costly procedure. Each raw blank of virgin Teflon costs around $150, and even a miniscule hint of contamination, such as hair, lint, dust particles, et cetera, will turn into large black specks in the blank. Many times these are not visible until a final operation – making for useless parts and wasted time.
Due to the cost and the many variables involved in producing perfect blanks, White Knight has recently undertaken the task of producing their own blanks. The powdered PTFE is weighed and poured into the mold (a stainless steel container with a removable bottom). The mold is then placed into a hydraulic press and the powder is compressed at approximately 3,500 psi, based on the size of the billet being pressed. The compressed billet is then removed from the mold (at this point the billet is solid, but will crumble like a dirt clod) and cured in an oven at around 700 degrees Fahrenheit. The curing/baking process will bring the Teflon molecules to the point where they will gel together.
Teflon must be molded in this slow and deliberate way, as it does not melt or share other common properties with most plastics. If heated too far beyond 700 degrees, Teflon will begin to turn into a gas, much like dry ice does as it melts. Depending on the size of the billet, a short curing cycle is around one day; longer cycles may take five to six days. There’s little doubt that the Simmons family will perfect, or at least improve on, this procedure as well.
As a result of their combined hard work, determination, unified creative thinking and steadfast faith, the Simmons family is making the most of opportunities and living their vision. We passed the rural street where White Knight is headquartered three times before getting it right. High-tech in country camouflage is always so deceiving. But there it was, White Knight and their daily dealings with incomprehensible numbers and thousands of pounds of virgin Teflon.