sensor history Index 02 Introduction 03 The Fairchild Semiconductor Days 05 The National Semiconductor Days 08 The Sensym Days 12 Art Zias 14 Next Sensors 16 All Sensors 16 Hans Keller 17 Other Silicon Valley Sensor Companies 21 Other US Silicon MEMS Companies 27 Silicon Senors in Europe and the Rest of the World 30 Significant Applications 32 The Millionaires Club 33 Some People to Remember 34 Some Comments from Art Zias 36 The Author 01 all sensors Introduction There are certain stories I tend to tell when we have visitors in Sunnyvale or when I first meet people in the sensor business.
The extent and detail of these stories vary as is appropriate with the interests of our visitors or the occasion. I like to recount some of the history of silicon based sensors in Silicon Valley and give some examples of applications we’ve worked on in the past. Often this triggers some common ground upon which we might have interests, people or other experiences in common to share. I shall try to share some of this by way of this news letter. 02 sensor history The Fairchild Semiconductor Days The beginning in the Valley For all practical purposes I’ve been directly involved with the first silicon sensor work in Silicon Valley.
The person most responsible for bringing sensor technology to the area was Art Zias. Art was a technical writer at Bell Labs while an engineering student in the late fifties. The physics of piezoresistance in silicon and germanium was derived from the work of Phann, Thurston and Smith at Bell and was chronicled by Art. Art also worked as a professional saxophone player at the major New York studios during the fifties. In his own words “I was skilled enough to play with the top jazz artists, but not talented enough to be ranked with them. Pfann’s work inspired Art to make a life long career of silicon sensors. Bill Pfann made a comment at the time that not only inspired Art but perhaps defined the industry “Now that we’ve studied the transduction effects in semiconductors for the purpose of getting rid of them, maybe they’re useful. ” In 1960, Art joined GE where he won a competition against Honeywell for an Airforce (WADC) contract on solid state motion transduction. That motivated Tony Kurtz to leave Honeywell and found Kulite. In 1964, Art joined Honeywell to start the Solid State Electronics Center (SSEC).
During the sixties, Art lead SSEC’s development of piezoresistive accelerometers and pressure sensors for the Aerospace, Industrial and Microswitch divisions. Hans Keller was then a physicist at SSEC. He later founded Keller Druckmestechnik in Switzerland. In 1969, Art joined exHoneyweller, Don Lynam, as director of Engineering at Fairchild Camera & Instrument’s Transducer operation. Gene Burk soon left Honeywell to join Art. Art credits Gene with the original work on bulk silicon micromachining. Prior to Gene’s work sensors did not incorporate three dimensional structures, only planar structures.
Don, Art and Gene Burk left Fairchild and founded IC Transducers (now Foxboro ICT) with Fairchild’s blessings in 1971. In 1972, Art and Bill Hare founded National Semiconductor’s transducer operation without Fairchild’s blessings. In addition to ICT, an effort continued at Fairchild aimed at automotive applications. At Fairchild the hope was to develop a manifold absolute pressure sensor, similar in technology to the ignition module, based on silicon piezoresistance technology. With Art’s departure the effort was stopped. National and Fairchild became involved in a legal dispute over the nature of Art’s departure.
What remained of the technology at Fairchild was sold to Bob Hood, became Cognition and was eventually sold to Emerson Electric, never to be heard of again. I met Art in 1973 at a golf outing arranged by a mutual friend and fellow engineer at Fairchild Semiconductor, Rick Schaffzin. Rick became president of IC Sensors in the eighties. Art has a horrible golf swing. It’s best that one just learning the game look away when Art swings to avoid the 03 all sensors Methuselah curse. Rumor has it that seeing Art’s swing may turn one into a pillar of salt.
At Fairchild we developed the first solid state ignition modules with Delco Electronics, shipping 50,000 modules a week during peak production. I was a process and product engineer for automotive and other hybrid products. The engineering manager was Rodney Smith, now president of Altera. 04 sensor history The National Semiconductor Days In the early seventies the only commercial silicon based sensor work in the Valley was Art’s work (just starting at National Semiconductor), Don Lynam at IC Transducers (also just starting) and the effort at Fairchild (coming to a close through Cognition. Elsewhere in the world there were other commercial efforts with the work continuing at Honeywell Microswitch, Hans Keller at Keller in Switzerland, Kulite in New Jersey and at Phillips in Europe. The largest research efforts were at the Universities in the United States. There were significant efforts at Case Western, under Dr. When Ko, Stanford under Dr. Kendall Wise, and by John Gragg at Carnegie Mellon. National Semiconductor wanted to get into the business because of the potential automotive applications. Art was asked by National’s management to explain “transduction. Art told them he would put it into the simplest terms, and one they could relate to best. He described transduction as the ability to take silicon and convert it to money. That appealed to National, Art was hired and the ten year transducer effort at National was to begin. Art has more accurately described the circumstances, as the events surrounding this statement also provide an insight into the character of National Semiconductor at the time. In the mid seventies I assumed responsibilities for marketing of all National’s hybrid products, including Transducers.
At the time there was a major effort by the car companies to develop an automotive MAP sensor. At National we worked with Delco Electronics and Ford to codevelop two types of MAP sensors. The Delco version had a sensor die similar to the Honeywell sensor die of the time and was packaged in a housing similar to the Fairchild ignition module. This product and versions of it are still manufactured by Delco and other aftermarket suppliers. Similar versions of this sensor were developed for all other major car companies in the world and its specification is the defacto industry standard.
The Ford version was a silicon variable capacitance pressure sensor. It is still manufactured today by both Ford and Motorola. However, it is not used by any other car manufacturer. It is more costly than the piezoresitive version. There are other thick film hybrid MAP sensors also serving this market. In 1977 I was participating in a Transducer Range Commanders conference in Seattle along with Joe Mallon, vice president of engineering at Kulite. At this time Joe had a ton of patents for silicon piezoresistive pressure sensor processing. In 1983 Joe, Kurt Peterson and Janusz Bryzek were to become cofounders of Novasensors; more on them later. ) I got to know Joe from this meeting and found him to be the most knowledgeable person at that time concerning temperature effects due to semiconductor processing for pressure sensors in silicon. Even today most companies reference his original work for determining appropriate concentration levels for dopants in silicon to set the temperature coefficient of resistance and sensitivity. 05 all sensors
In 1978 I was attending Semicon West in San Francisco and was at “Herr Doktor” Janusz Bryzek’s presentation on discrete temperature compensation of silicon pressure sensors. Janusz presented a circuit that had at least twenty amplifiers, and several hundred resistors and many potentiometers. The most elaborate scheme for temperature compensation I had ever seen, truly a technical wonder to behold. He was asked by a member of the audience “Doktor Bryzek what is the error in such a compensation with so many components? ” Without hesitation Janusz replied “there is no error, it…. s perfect! ” At the time I felt he could quite possibly be right but wondered how he would test it. (An engineers mentality, not a marketing mentality. ) From this conference I got to know Janusz. During this same time period American Hospital Supply approached National for a $5. 00 disposable blood pressure sensor. The first work started then for what is today, most probably, the second largest pressure sensor application in the world behind the automotive MAP sensor. The 1977 National Semiconductors Transducer Handbook became the reference book in the transducer business.
Most sections of this book are still reprinted with each reprint of the Sensym handbook. This handbook is still the reference book of choice for pressure sensors. The 1977 handbook was unique because each section had an unusual introductory title and preface including, “The pig who squealed Dixie,” a section concerning acoustic measurements and “Samson and Delightful,” a section on signal conditioning. This book was the result of a years work by Art, Ray Pitts a Ph. D. in physics who was consulting and rewriting the bible at this time, and myself. Ray was the major contributor.
He had an unhappy ending to his story at National and a tragic ending to his life shortly thereafter. In 1980 I became Director of Operations for Transducer Products at National and Art Zias reported to me. It was a truly challenging and joyful time period for us all as Art kept everyone on their toes and entertained. In addition to engineering, Art performed as master of ceremony at the National Semiconductor annual sales meeting and would use me as a sounding board for many of his anecdotes. One of his more memorable ones was about Charley Sporck, founder and CEO of National Semiconductor.
In reaction to financial analysts criticism of him at the time, Charley made the statement “he would chomp on groins and spit testicles. ” Art, in reference to this statement told an audience of several hundred National employees and sales Reps “that it just goes to show you that angry rich men can develop strange gourmet fetish’s. ” The charter for the transducer business was to determine what was needed to grow the business to $100 million in a short time period. At the time I didn’t know it, but the only other alternative was to exit the business. 6 sensor history National Semiconductor notable persons involved with the Transducer operations. Most notable was Mike Scott, director of operations for hybrid and transducer products from 1974 to roughly 1979. I reported to Mike during this time period and he was the most knowledgeable marketing, and possibly the brightest person I have ever met. Mike, who previously worked for Mike Markula at Fairchild, left National to become the first president of Apple Computer and left Apple in 1983 when he and Steve Jobs did not see things the same.
Markula, Chairman of the Board for Apple, opted for Steve instead of Mike. Mike left Apple at this time with his eight million shares of Apple stock and has enjoyed himself ever since. He did have one fling in the satellite launching business with the failed launch of their first satellite, and company, Starstruck. The concept for their satellite had considerable technical appeal. But in the end they had an expensive boat ride that saw their satellite and investment forever disappear into the depths of the Pacific Ocean. Floyd Kvamme was Vice President of marketing and sales for National.
Pierre Lamond headed R. Both Floyd and Pierre are very well known today in the venture capital community. At National our semiconductor fab processing was done in the linear group, headed by Bob Swanson. Bob left National with a team of National linear people and started Linear Technology, a very profitable semiconductor company today. Their leaving National caused Charley Sporck to file legal action against the group as it “appeared” unusual to see them talking daily in the cafeteria for some time prior to leaving. Especially since they had never socialized before this time.
One of the cofounders of Linear, Brent Welling for whom I worked for a brief time period at National, would later join us at Sensym as Vice President of marketing and sales. At National I was a member of their eleemosynary committee and had the opportunity to visit a sensor group at Stanford University. Kendall Wise was head of the effort and was just leaving to form a sensor research effort at the University of Michigan. I met Jim Knutti who was involved with an implanted integrated injection logic, combination pressure and temperature sensor used to monitor bodily functions of sheep, funded by the National Institute of Health.
Jim worked with Dr. Henry Allen and the two of them later (1984? ) started a company to manufacture force sensors using silicon for what Art had earlier published as “the fingertips of the robot. ” This company, Transensory Devices Inc , was acquired by IC Sensors and Jim and Henry stayed with IC Sensors. Jim left a short time after the acquisition and started a sensor operation in Switzerland with Ascom. Ascom was eventually sold, there was a fire in their fab, and finally they exited this business.
Henry joined Jim and the work done with Ascom allowed the two of them to start Silicon Microstructures in 1992. SMI was acquired by Exar in 1995 and Jim and Henry continue to be active at SMI/Exar. They have done some very good work with silicon stress concentration, modeling thereof, and silicon structures for low pressure devices and accelerometers. 07 all sensors The Sensym days In 1982 after I made a presentation to National management stating it was not realistic to expect the Transducer business to become at $100 million business in the foreseeable future I was instructed to sell the business.
At the time John Nesheim was treasurer for National and provided guidance for me during this process. John later formed Ministry Management with Art Linkletter, of television fame, and has written several books concerning venture capital financing. At that time my marketing manager was Manny Naik, now the president of Integrated Sensor Solutions. Manny and I talked with Joe Mallon and the three of us considered how we might get into the business ourselves. We decided to invite Janusz Bryzek into the discussions as well.
After many meetings suffice it to say that we could not agree on a structure for the company the (“Office of the President” later adopted at Novasensors, did not appeal to me) and I decided to propose a leveraged buyout of National’s operation and Janusz would join us as Vice President of Engineering. Manny stayed at National, later to leave and found Integrated Sensor Solutions. ISS is now active in pressure sensors for automotive applications and has strategic relationships with companies in Japan, Germany and Breed Automotive in the United States. Manny is, without doubt, the best marketing person in the pressure sensor business.
I was given one month by National to arrange financing for the purchase of the Transducer Group. Through John Nesheim’s referral I was able to arrange quick financing from Robertson, Coleman and Stephen’s, now Robertson, Stephens & Company in San Francisco through Bob Cummings. Bob also got Crosspoint Investments to contribute and we developed a business plan with the help of John Mumford, general partner for Crosspoint. I was very lucky to have John Nesheim’s referral and introduction to the legitimate financial community. We completed the purchase of the business in October 1982, from this Sensym was born.
I had a very good relationship for the prior five years with our European marketing manager in Germany, Helmut Gutgesell. He offered to start a company in Germany with mutual exclusivity for the Sensym products. Thus was born Sensortechnics GmbH. Sensortechnics is today one of the more successful value added suppliers of pressure sensors in Europe. I located Sensym at 1253 Reamwood Avenue, Sunnyvale, a facility that had been recently vacated by Interdesign. Interdesign had been sold to Ferranti and they moved to Scotts Valley. This address may look familiar as it is where I currently reside with Data Instruments ASG.
We put in a four inch semiconductor fabrication facility and had the capability to build linear IC’s as well as silicon micromachined structures. Some of our notable work at Sensym included disposable blood pressure sensors for both invasive and non invasive application, including catheter tipped disposable pressure sensors for multilumen catheters down to a size of four french (less than 0. 023″ wide. ) We 08 sensor history developed a hybrid module for Michelin including a pressure and temperature sensor with a full custom IC. (All of which was manufactured in house. ) The initial use was for tire pressure sensing on the BMW model 850.
We developed a full custom artillery shell distance sensor for safe and arm electronics. This included our first silicon accelerometer. The module performed a double integration of acceleration to determine distance. And we developed the first, low cost digital tire pressure gauge. It was, by far, the most sophisticated pressure sensor of its time for the price. The tire pressure business was a business, within a business and had a story of its own. In the eighties Sensym was where a significant portion of the industry research (more correctly, development) was being done. Novasensors did research, Sensym did development.
Janusz Bryzek stayed with us for about three months and left to join Don Lynam who had just left Foxboro ICT to start IC Sensors. In his stead we hired John Gragg from Motorola to manage our engineering efforts. John had worked at Carnegie Mellon on shear strain in silicon for the purpose of manufacturing pressure sensors. This technology had its roots at the Bell Labs in the work of Pfann and Thurston. Three basic technologies are used to manufacture silicon based pressure sensors; variable capacitance, uniaxial longitudinal and transverse strain piezoresistance and shear strain piezoresistance.
There are tradeoffs for each rendering one more suitable than the other for particular applications. John and Carl Derrington had been instrumental in taking this technology from the university and commercializing it at Motorola. Motorola is the only company to employ both piezoresistance and variable capacitance pressure sensing technologies commercially. Motorola is currently the only United States non captive supplier of OEM automotive pressure sensors. John stayed with Sensym less than a year. His wife didn’t want to live with his commute from Phoenix to San Jose and would not move from their home in Phoenix.
John returned to Motorola to pursue interests in another Motorola technology. Automotive applications have been the catalyst for much of the silicon sensor development. It first started with the manifold absolute pressure sensor and more recently has extended to air bag crash sensors and fuel vapor sensing and has been considered for oil pressure, comfort seat bladders in memory seats, air conditioning pressure switches, tire pressure and intelligent shock absorbers. (Not to mention all the off-road vehicle and truck applications. ) Research efforts have been funded in Germany by Siemens and Fraunhauffer Institute.
Siemens acquired the Bendix sensor research group when Bendix’s automotive business was acquired by Siemens. This group had received over fifty million dollars in funding when part of Bendix. The research efforts in Germany have been largely funded by the government (over several hundred million dollars) and the auto industry. In spite of all this funding the only company that sold products was one small operation near 09 all sensors Munich owned and operated by Texas Instrument manufacturing only piezoresistive sensors for disposable blood pressure. This business ended several years ago.
In 1989, seven years after having taken money from the venture capital folks, as is common in the venture business it was time for Sensym to provide a return on their investment. At Sensym we raised money one other time, in 1984, when a note due National secured by my house was due and I did not have the funds to pay it. To make a long story short, National voided the note and took an equity position in Sensym thanks to Charley Sporck and Gary Arnold, Nationals Vice President of Finance at the time and current member of National Semiconductor’s Board of Directors.
In 1989 I retained Bob Harris of Kahn & Harris, now Harris-Roja, for the purpose of selling Sensym. We received much interest from a large number of companies interested in acquiring Sensym. After close to twenty visits we had a short list of less than five companies based upon their management compatibility and the price they would be willing to pay. In the end we opted to accept an offer from Hawker Siddeley. Our investors received between seven and ten times their original investment as a return on their investment. The return on investment was acceptable.
Hawker Siddeley had a large sensor group in the United States managed by Dale Bennett in Rhode Island called Fasco Sensors and Controls. This group included Fasco in North Carolina, Elmwood Sensors in Rhode Island, Aerospace and Aviation Inc in Long Island, Mason in Southern California, Laserdata in Florida, Clairostat in New England, and Senisys a fiber optic module company in Texas. I would become very familiar with all these companies through group meetings and when I was asked to provide technical assessment for each of them.
We hired Art Zias to consult for us for a year and to provide a technical inventory of each of the Fasco businesses. In 1981 Hawker Siddeley attempted to fend off a hostile takeover by BTR, another British conglomerate. During that time period we came close to being able to repurchase Sensym from Hawker Siddeley but the deal didn’t get done before BTR acquired control of Hawker and therefore of Sensym. BTR has a management philosophy totally different from what had been the norm for Hawker Siddeley. BTR has been very successful with their approach; acquire a company, raise prices ten percent and cut labor costs by ten percent.
Vale, fifteen percent to the bottom line. Each subsequent year a BTR plan begins with raising prices by inflation plus one percent and budgeting labor costs to increase by inflation less one percent. Very simple. Such is the norm for a BTR company. Suffice it to say that such an operation takes only an accountant to run and I submitted my resignation at the end of my contract, March 1992. Prior to leaving Sensym, I offered to BTR that I would purchase Sensym for a reasonable price rather than allow the fate of the gradual demise of the business operating under such a system. They decided to decline my offer.
Sensym continues today in the BTR environment. 10 sensor history BTR and Siebe merged in 1997 and with this merger Sensym and Foxboro/ICT were consolidated under Chris Cartsonas. The ICT facility was sold and all operations consolidated with Sensym. Sensym’s manufacturing is done primarily in Juarez, Mexico, with silicon processing still in Milpitas. The Sensym name is being replace by Invensys Sensor Systems. This is a group name for all companies that were formerly the Sensor Group of BTR. 11 all sensors Art Zias But what became of Art Zias you ask. During Christmas 1996 and New Year 1997, Art and his lovely wife, Ellie, toured Africa.
There were reports their trip was partially funded by the Oakland school district for research into the true origins of Ebonics. Yet other reports have Art starting another sensor company or as lead saxophone for the Swahili military marching band. Based upon Art’s background any one of the stories could, in fact, be true. Upon leaving National Semiconductor in 1982 Art went to be cofounder of Tricomp Sensors, ultimately a publicly funded company that went belly up thanks to the fine efforts of Ralph Voerst their principal investor and fund raiser par excellence.
Art then founded Captorr along with professor Barry Block. Barry is “the guru of variable capacitance, silicon to pyrex to silicon microstructures” having made a name for himself through the sale of the technology to Signetics in the seventies for automotive accelerometers. Each person associated with Barry has a different word for the “name” he has made for himself. I have found him to be incredibly interesting. However, it is a little bit disconcerting when all your meetings with him include his attorney and you have been told that he has made a significant amount of his money by way of law suits.
Captorr contracted with Dresser Industries to develop and “turn-key” a very low pressure (0. 1 inch of water column full scale) variable capacitance differential pressure transducer. The technology developed for Dresser is now used in Dresser’s low pressure devices and in some products manufactured though a Dresser Nagano joint venture in Japan. Other silicon pressure sensors manufactured in Japan by Fujikura, Nagano and others had there origins via technology transfers between Honeywell, Dresser, Foxboro ICT and their Japanese partners. Captorr technology rights were sold to Dresser and Art and Barry left for other pursuits.
Art joined Teknekron Sensor Development Corp in Menlo Park, a company formed by a wealthy man, Harvey Wagner, residing on a ranch near Lake Tahoe. Apparently Harvey made a lot of money when he sold a credit report software company to TRW. Teknekron was formed for the purpose of developing companies in an incubator environment for the purpose of liquidity and provide a large return on investment to the principal investor, Harvey. The working principals where a handful of Phd’s from industry and academia with interests in sensors of all types. The facility had state of the art sensor semiconductor and micromachining capability.
In the end TSD, had its funding terminated when the forecast for the return on investment was determined to be too low. Four of the individuals, Martin Przybylski as President, Art as VP engineering, Shawn Kahil in engineering and Norm Nystrom for facilities left to form a silicon gas flowmetering company called Fluid IC. This company had funding for the purpose of developing a replacement for the home natural gas meter and other monitoring system metering in the gas distribution business. Fluid IC was absorbed by Itron and 12 sensor history ceased operation in 1995. Art now consults through Ziasense, a “dba” of CapTorr.
Art is an active consultant to several companies in the sensor industry. He provides a short tutorial on silicon sensor technology for newcomers to the technology or full courses for those skilled in the technology and business. Art also is an active director of MCA Technologies, a promising new company founded by Ali Rastegar, that provides ASIC signal conditioning circuits for sensors. To all that know Art he is truly a fine person and has been instrumental in the formation of the silicon micromachining industry. However, he’s still has a horrible golf swing. 13 all sensors NeXt Sensors
In 1992 I retired for most of the year. Retirement is not what one might make it out to be, especially for one who has worked since he was twelve years old and enjoyed doing it. A friend of mine that retired in his forties after making enough money to do so from stock options would say “I don’t miss the rat race but I do miss some of the rats! ” I enjoy both, as long as you know what race you’re in. In early 1993 I informed Sensym I would be participating in the Sensor Show in San Jose and since I had a two year “not-to-compete” agreement they should determine what they might want to do.
Sensym filed for a temporary restraining order to prevent me from participating in the show. The courts ruled against their request and I was allowed to attend with certain provisions. Sensym spent a considerable amount of legal time and dollars to attempt to keep me out of the sensor business. We had differing opinions regarding the not to compete provision that was finally settled by the courts. In the end, I learned a lot about the law and the legal system and Sensym spent a lot of money to prevent me from competing in the United States until June 1, 1994.
I believe had Sensym spent all the money they spent on legal bills on product improvements they would be much better off today than they are. Since I was having trouble getting started in the United States I exhibited at the Sensor Show in Nuremburg, Germany in May, 1993. I had a booth with no products, only some flowers and myself. Hans Keller stopped by and asked if I was now in the flower business. It was very fortunate I went to this show as I met Alexander Breitenbach. Alexander had just, within weeks of the show, left Sensortechnics Gmbh.
Alexander had been the best salesman at Sensortechnics and the person responsible for a significant portion of their business. By the beginning of 1994 Alexander and I founded NeXt Sensors Gmbh and we were in the sensor business in Europe. At least, on paper we were in the business. I incorporated NeXt Sensors in the United States and started production of some pressure sensors similar to Sensym’s with improved performance in June, 1994. Two of the best people I have ever had the pleasure to work with joined me during the first month, Dale Dauenhauer, my brother and Marissa Magcase.
Marissa had been our Quality Assurance manager at Sensym. Fred Adamic, who was Vice President of Engineering and Manufacturing for Sensym until 1993 join us in our facility, not as an employee rather he started his own company, Spectrum MicroDevices. Fred is still here, and Spectrum MicroDevices is still active. Fred is pursuing dielectrically isolated structures in silicon as well as some novel silicon gage structures. During the early days we received invaluable assistance from a couple companies and some needed financial support from some other people.
Tim Shotter, founder of Gandolf who had designed the tire pressure gage for Sensym, provided product design support. Derek Bowers, founder of DB Design who had worked at Sensym ten years earlier 14 sensor history provided package design and test fixture design support. I received financial support from Robertson & Stephens and from John Easton, president of Sensotec. The support from all was greatly appreciated. By mid 1995 I recognized we would need more financial support than I could afford and I retained the services, again, of Harris-Roja to see what could be done.
Since much of the investment was needed to establish a United States sales and marketing effort we decided to look for companies interested in a merger and use their existing infrastructure. In a short time period we had the interest of two companies, Data Instruments and Telcom Semiconductor. My personal interest was to work a deal with Telcom because I have known their Vice President of finance, Mike O’Malley, for close to twenty years and I was very favorably impressed by their CEO, Phil Drayer, who I had seen give a presentation at the Monterey AEA’s Emerging Companies Financial Conference.
We merged NeXt Sensors with Data Instruments and created Data Instruments Advanced Silicon Group in December 1994. History has yet to write itself as to what will ultimately happen with DIASG. In 1995 Data Instruments also acquired NeXt Sensors Gmbh and consolidated all Data Instruments European Marketing and Sales into the merged company Data Instruments -Next Sensors GmbH in northern Germany, close to Hannover. In January, 1996 Sensymtronic, in Paris, France was acquired by Data Instruments and merged into Data Instruments France. The company president for each company continues with the respective operations.
In November, 1998 Data Instruments was sold to Honeywell. The ASG group (NeXt Sensors) was closed and moved to Freeport, Il. NeXt Sensors people assisted in the six month process of transition from Sunnyvale to Freeport. All key people remain in the Bay Area. All key people at Data Instruments in Acton, MA are no longer with the company. 15 all sensors All Sensors In May, 1999 All Sensors Corporation was formed with Dennis Dauenhauer as the sole employee. In November, 1999 the assets of General Sensors were acquired. Hans Keller Hans is one of the “characters” in the industry.
He is deserving of respect not only for his longevity and accomplishments in the industry but for his energy and enthusiasm. I first met Hans in Wintethur, Switzerland while visiting his facility with Helmut Gutgesell in the spring of 1983. The meeting lasted most of the morning and was conducted primarily with Hans yelling and arm waving about how I, and everyone else in Silicon Valley, were idiots and how he would bury us. (I believe he takes credit for the origins of this phrase and that Kruschev stole it from him. ) I gained instant respect for Hans because I had never met someone that could be so passionate about their business.
He certainly is the only one I had met that was equally adept at expressing his beliefs in either German, English or French. At this time Keller was still performing micromachining in the purest sense, they micro machined, drilled, the silicon. I assumed they felt that if it was good enough for Rolex it was good enough for Keller. Some years after this meeting I was told that Hans passion was bordering on the extreme, it was alleged that he file a law suit against Gillette for their advertisement of the razor called “Sensor. ” Apparently Hans had concerned about our industry being confused by these ads with the razor business.
I never did hear the outcome of this “rumor” nor did I ever ask Hans if it was real or a rumor. The best thing I can say about Hans is, he has my respect! 16 sensor history Other Silicon Valley Sensor Companies EG/IC Sensors IC Sensors was started by Don Lynam in 1983 and Don was joined shortly thereafter by Janusz Bryzek. The majority of the funding was from Borg Warner to develop automotive MAP sensors. Eventually IC Sensors became very active in blood pressure and for awhile this was their most successful product line. Rick Schaffzin was hired by the Board of Directors in the late eighties.
The company became the leader in silicon crash sensors for automotive air bags with Breed as one of their largest customers. The company was sold to EG in 1994 and reports to the Reticon Group of EG (Ed Snow), a group Rick had worked for after leaving National Semiconductor. Rick left IC Sensors shortly after the acquisition and is currently not active in the industry. IC Sensors, Novasensors and Sensym are all similar sized companies. IC Sensors was acquired by Measurement Specialities in 2000. Operations are being consolidated and some transferred to China.
Foxboro, ICT Formerly IC Transducer, this was the first silicon sensor company to be acquired. Foxboro acquired the company in 1974 for the purpose of developing technology to be included in their pressure transmitters. ICT evolved into a captive supplier to Foxboro even though they maintain a commercial marketing effort. ICT has been marketed for acquisition on several occasions but the price has always been higher than any reasonable buyer has been willing to offer. Foxboro was acquire a couple years ago by Siebe and it is possible the price may be more reasonable.
The company maintains a low profile in the industry. It is now integrated into Sensym, aka Invensys Sensor Systems. Integrated Sensor Solutions A company started by Manny Naik. They enjoy success selling manifold absolute pressure sensors developed with an ASIC in the automotive aftermarket. The ASIC was developed from technology at the Honeywell Research Center which was closed in the 1980’s. Their initial sales were to McGuane. Their more recent efforts have been aimed at isolated pressure sensors for industrial applications and attempting to find more applications for their ASIC technology.
Their ASIC technology is inferior to the ASIC technology at MCA Technologies. The basic premise of their ASIC is to provide an elegant solution to a simple problem. To date they have not been able to offer performance much better than can be achieved using a standard dual op amp. ISS has no sensor fab capability. They recently lost the services of one of their most senior employees, Steve Nasiri. They tend to compete only on price and do not have a price structure to allow this strategy to be successful in the long run. ISS was acquired by Texas Instruments in 1999.
Most of the operation has been transferred to 17 all sensors Attleboro, MA. Manny Naik has started a consulting company. The acquisition was very good for both parties. ISS received a very good valuation, over $50 million, and TI acquired a business that will generate over a $100 million annual business. Lucas Novasensors Started in 1985 by Bryzek, Mallon and Peterson. Curt Peterson had done work at IBM, South San Jose. Peterson gained industry exposure when his article on silicon micromachining was published in Scientific American. Prior to this article the technology was referred to as chemical etching.
Novasensors was funded by Schlumberger. Schlumberger had been a significant potential customer of IC Sensors where Janusz had been employed prior to the funding by Schlumberger of Novasensors. Nova hired Roger Grace to promote the company and promote the individuals of the company. Roger and Janusz had worked together at Foxboro, ICT. A similar promotional effort for Sensym, when Janusz was active there, was declined. It was probably a mistake I made by not using his services. Roger Grace was able to provide Novasensors with media and press coverage beyond what the company deserved.
I suspect some of this success was coincident with the emergence of Sensors Magazine which did, and still does, have close ties to Roger and Janusz. Roger Grace, now with Grace Consulting offers his services in this industry. Roger deserves much of the credit for the success and notoriety Novasensors received. Janusz was Sensors magazine’s Life Time Achievement recipient a couple years ago thanks to Rogers work on his behalf. Nova did some original work. The fusion bonding work to allow very small structures was unique to Nova but for the most part what was done was duplication or evolution of previous work.
Nova consumed more money than any previous sensor company and provided the lowest return to the investors of any prior investment. The trio that started the company did not share a similar fate. Nova was acquired by Lucas after Sensym turned down an offer from Lucas to purchase Sensym. The acquisition of Sensym set a nice market price for sensor companies when Nova was acquired. Novasensors was merged with another Lucas sensor business, Schaevitz and are part of the Lucas Control Systems Products Group. It appears likely that the Novasensors name will disappear altogether in lieu of Lucas or the business will be divested.
Only in recent years has the business become marginally profitable. The original founding trio are no longer active at Lucas. Peterson is active at Stanford University in MEMS development, Mallon is president and CEO of Measurements Specialties Inc. Janusz is now active with Maxim Integrated Circuits. Some good blood pressure and accelerometer capability is resident in the company. They were also recently awarded a significant contract for silicon valve development. Lucas was acquired recently by Varity and is part of an overall business review to determine hich companies are in businesses they wish to continue to support. Maxim Integrated Circuits 18 sensor history Maxim’s involvement is too new to have much to comment about, it was announced in January, 1997. It is to be managed by Janusz Bryzek, employ Steve (Saeed) Nasiri and have the funding and support of Maxim. An effort to include MCA Technologies also appears likely. The sensor business, excluding ASIC’s used by sensors, has been dropped by Maxim. Janusz and Steve have started another company to specialize in MEMS products for fiber optic switching applications, Transparent Optical Inc.
Microflow Analytical Founded by Curtis Ray. The company was acquire a couple years ago by a medical company in Texas. They have developed some interesting valve technology using titanium-nickel (TiNi) thin films. They continue mainly as a research and development operation with no significant manufacturing capability. Microscape A company just getting started, although they have been active for a couple years. Their capability is more technology oriented, and in particular new surface micromachining technology oriented.
They employ several scientist type persons with prior university and sensor development sensor experience. Microsensor Technology Inc Originally started by some Stanford students who have departed many years ago. The company has a small silicon micromachining operation and supports their own requirements for their gas chromatography instruments. They have very good technology to support this application. This company has a huge potential for growth with the proper technical support. The business is managed and partially owned by Bill Higdon, a very dynamic individual.
Sensym Today Sensym operates successfully in the BTR environment. The company owes much of their continued success to their marketing relationship with Sensortechnics, GmbH. The company has an excellent fab facility but lacks any technical expertise to do anything but maintain existing products. The company will continue to be a cash cow for BTR. Sentir, subsidiary of Merit Medical A business started and funded by Manny Fernandez and Fred Lampoplis. Manny was founder and principal of IC Transducer and worked for Don Lynam at both Foxboro ICT and IC Sensors.
Manny has developed a nice, little, diffused semiconductor piezoresistive manufacturing operation ca- 19 all sensors pable of supporting small volumes for medical applications. Their devices are used by Merit Medical for blood pressure, angioplasty pressure and intrauterine pressure measurement. Gene Burke, an industry veteran of some thirty years in various capacities, is currently Sentir’s marketing manager and maintains close ties to Art Zias. 20 sensor history Other US Silicon MEMS Companies Analog Devices Analog was the first company to introduce a semiconductor accelerometer suitable for automotive air bag applications.
This was based upon surface micromachining in silicon and developed in conjunction with MIT. They have looked at other sensors. Like most analog semiconductor manufactures including National Semiconductor, Linear Technology, Maxim and Telcom Semiconductor they offer silicon temperature sensors based upon the band gap effect in silicon developed by Bob Dobkin, who is well known in the industry for his work on band gap references. Data Instruments Acton, Mass While this was written primarily for an audience familiar with Data Instruments there may be some readers not familiar with the company.
Therefore a brief description is in order. I first worked with DI in 1982. We had some isolated pressure sensors I did not want to continue manufacturing at Sensym that were part of the acquisition. I approached Data Instruments about having them supply us a part we would private label and sell. While the business didn’t amount to much the process allow me to make first contact with some of the people at Data Instruments. By my understanding DI is the only employee owned sensor company. Ed Colbert is the founder, current Chairman of the Board and remains the largest shareholder.
Ed, however, has allowed the employees to participate in the success of the company such that now the employees as a group own a significant portion of the company. Peter Russo, President, joined the company in the early eighties out of the Harvard Business School with his MBA. Peter has successfully managed the company from a small pressure sensor company to a global company capable of being the largest sensor company in the world within the next couple of years. I merged NeXt Sensors with Data Instruments in the hope of contibuting to that goal.
Delco Electronics Indiana Without question, Delco has the largest silicon sensor capacity in the world. Currently they are able to process tens of millions of pressure sensors and crash sensors. They are strictly an automotive supplier. They periodically have interests in other markets. However they lack the infrastructure to address markets other than automotive. They have some of the best sensor manufacturing technology in the world. Dresser Industries CT Dresser’s is focused on very low pressure using technology developed by Captorr using silicon variable capacitance.
They have a very good, expensive technology capable of providing excellent products for measuring less than one inch water full scale pressure. 21 all sensors Ford PA Completely captive to Ford. Historically they have provided one half of the SCAP devices used by Ford. This work is based upon the efforts of Joe Giachinno of Ford, MI. The SCAP is Joe’s original work and he managed develop within Ford and between National Semiconductor and Motorola AIEG. Keller America now Keller-PSI In the early eighties Hans Keller and Art Zias started Keller America. Dick Grove provided some sales assistance.
The operation was started to provide sales and marketing for Keller’s products in North America and to develop an ASIC using PROM compensation similar to the work being done at the same time by Roger Reinhart at Atmos. PSI, a company in Virginia represented by Dick Grove, became interested in Keller America for using their compensation for some cryogenic pressure sensors. Doug Juanarena had purchased PSI from his partner in the late eighties. Doug struck a deal with Hans, Art and Dick such that Keller America became part of PSI and thus KellerPSI was created.
Kulite Semiconductor One of the oldest semiconductor based sensor manufacturers in the world. Much of the fabrication technology was developed by Joe Mallon during his time at Kulite in the 1970’s. Measurement Specialties MSI is the only publicly owned sensor company. They have manufacturing in China. Their main business is consumer related products. The principles are ex Kulite employees. With the recent addition of Joe Mallon as president the company is attempting to shift product focus to other, non consumer, markets.
Motorola AIEG The first sensors manufactured by this group were based upon the Ford SCAP (silicon capacitive absolute pressure) sensors developed by Ford and National Semiconductor. More recently sensors for fuel vapor recovery and MAP sensors have utilized piezoresistive sensors of the semiconductor group. This is currently a source of litigation between Sensym and Motorola. The group has manufacturing near Chicago and in Buffalo, New York. Motorola Semiconductor Their effort started with work developed by John Gragg and Carl Derrington in the mid 1970’s using shear strain piezoresistive structures for manifold absolute pressure sensors.
Today they are 22 sensor history the largest non captive manufacturer of silicon based sensors in the world. The semiconductor group is currently investing heavily in accelerometers and chemical sensors. PSI Virginia See reference above under Keller-PSI. PSI uses silicon sensor die from various sources for high end pressure sensors including cryogenic applications. PSI Tronics CA PSI specializes in using silicon gages for isolated pressure sensors and digital gauges. Until Span developed another technology for use in their semiconductor gas cabinet sensors Span was a significant customer for PSI.
Span TX Span is in the process of replacing sensors based upon silicon gauges with thin film based sensors. They only serve the high purity semiconductor market. Sensotec Ohio Sensotec is owned by John Easton and is a silently, successful company in the sensor/transducer business. Their sales level put them in the top tier of suppliers. They focus on small, high value added and high margin markets with what ever technology is necessary to be competitive. SSI-Controls Technology Wisconsin. Automotive speed sensor company with current activities targeting pressure sensors using technology developed at University of Wisconsin.
The pressure sensors are in development for automotive applications with other applications also possible. They are currently having technical difficulties. Recently they lost the services of the one of the best automotive sensors marketing specialist, Alby Berman, who had previously worked for Fasco. Company post obitum In addition to several companies mentioned above that have entered and exited the sensor business the following lists some additional companies. Ametek PRT division Ametek entered the silicon sensor business to provide components for isolated, fluid filled industrial sensors and transducers.
They did so by investing in a semiconductor fab. They learned after a short period of time they could not generate enough revenue to absorbed the overhead costs of the 23 all sensors fab. They closed the fab portion of the operation. They continue manufacturing pressure sensors but now buy the sensor in die form and complete the remainder of the sensor. Burr-Brown Their effort failed as is only appropriate for a company whose comment concerning the technology was “How difficult can it be? It’s only four resistors in a piece of silicon. ” Microsensors, Inc.
Chicago, IL Microsensors was funded by Knowles. The company ceased operation several years ago. Although sensors are sill used by Knowles for hearing aid applications. The technology developed at Microsensors used silicon variable capacitance in conjunction with CMOS circuitry to provide an integrated structure. Their work can be reviewed in several patents that may, or may not be currently maintained. The business was for sale for about one year with no takers. Rohm Sunnyvale, CA Rohm has been the primary foundry for Exar since the operation was sold to Rohm several years ago.
They have also been the foundry of choice for SMI. Within the past couple years the relationship between the parties strained and Rohm created a micromachining business that was managed by Taka Otagowa. This lasted a very short time period. Seaway Semiconductor I include Seaway as having been in the business and then gone out of the business but I’m not sure they were ever really in the business, in spite of the fact that I’ve visited and toured their facility. Spectramed Oxnard, CA Spectramed was the first high volume manufacturer of a sensor similar to today’s blood pressure sensor.
They were unable to compete with the larger medical companies. Some of their assets and people are now working on a silicon based sensor effort for Kavlico. Technology was developed by Buzz Moran. SRI Menlo Park Mark Madou did a leverage buyout of the MEMS technology at SRI with funding from Teknekron, creating Teknekron Sensor Development. The level of investment and the multiple placed upon this investment couple with additional investments created a business with a paper valuation far in excess of what the business could ever be worth.
This was the beginning of the end for the company. 24 sensor history Texas Instruments Gmbh Located near Munich until 1994 the facility produced piezoresistive pressure sensors manufactured in Slovania by Iskra and shipped to PV Berg. The business was never large enough to support the effort. Sensors in the Universities Case Western The oldest active silicon sensor based research in the United States. It’s activities are the result of Professor When Ko. Most of their work has been funded by the National Institute of Health. MIT I am not as familiar with the work at MIT.
It looks to be mostly under the direction of Steve Santori and to involve surface micromachining and interconnect technology. Stanford University The original work was initiated by Prof. Angel and carried on by Kendall Wise. Most of this work was funded by the National Institute of Health and was most active in the seventies. Several companies started from the efforts that had there origins at Stanford, none with any notable success to date. UC Berkeley The University at Berkeley has had, for at least twenty years, two significant efforts in sensors one for physical sensors and one for chemical sensors.
The physical sensor effort has avoided tradition transduction effect sensors and focused more on micromechanical structures such as micromotors, micropumps and microvalves. Very little of their work has managed to be transferred into any viable commercial application. UC Davis A very small effort has been funded for about ten years applicable to sensors and other semiconductor processing. University of Michigan The program at the University of Michigan was started by Kendall Wise when he left Stanford. They have maintain this sensor research and development for over twenty years. It is some of the more 5 all sensors significant work in the field. They are funded by both the automotive industry and the government. Most of their work has been with computer simulation of physical structures and the use of computer models for predictive analysis. University of Washington Washington has both chemical and physical sensor work active. The facility, when I last visited, was excellent for state of the art processing. At the time the groups involved with sensors and the funding for this effort was done so to stimulate small business development in the sensor area and create Washington based companies.
To date there has been no indication that this has been successful. University of Wisconsin Professor Guckell has receive excellent reviews for the sensor groups work under his direction at the University of Wisconsin. They do a lot of work in both bulk and surface micromachining and in conjunction with standard CMOS processing and IC signal conditioning. They have successfully licensed their technology, most notably some to SSI in Wisconsin. 26 sensor history Silicon Sensors in Europe and the Rest of the World
Aktiv-Electronic Berlin, Germany This is a company I took a close look at after the communist break up. The company was for sale at a very low price. When I found that Seimens had passed on the opportunity to buy them, I who can’t even speak German, decided they were a hell of a lot better qualified to judge the business and I declined as well. It looks to be a company that will only interfere with the market in Europe until they exit the business. Druck England In the seventies the man most responsible for the pressure sensor work at Lucas in Birmingham, Mike Bertioli, left Lucas to found Druck.
Fujikura Japan Fujikura has been in the business for over ten years and continues serving the pressure sensor market by buying sensors in die form and doing basic packaging. Iskra Hypot, Ljubljana, Slovenia. Some nice work is being done in a hybrid operation using silicon die from outside companies. They started their original work prior to the break up of the communist system for blood pressure sensors for PV Berg in Germany. I expect this company will have tough times ahead as they are in a very price competitive market. Lucas Birmingham, England It is possible this facility has been closed as my last visit to it was in the mid eighties.
Even so, I am aware that several of the persons responsible for their silicon based sensors from the mid seventies are still active with Lucas. They have excellent engineering understanding of silicon based sensors. Magnetti-Marelli Italy Strictly an automotive sensor manufacturer that has converted from ceramic sensor based MAP sensors to silicon based. I have only seen the ceramic based operation and can not comment on their silicon capability. Microsensors Xian, China A company with a joint venture with Hans Keller. It was started by some people who had represented IC Sensors, the main principal was Victor Li.
They started using die from the United States and doing packaging in China. They currently have good packaging and compensation capability for stainless steel isolated pressure sensors and are the major player in China. 27 all sensors Sensortechnics Germany I have mentioned Sensortechnics Gmbh. This is the most recognized pressure sensor company in Europe because of their success throughout all countries in Europe. They have a very strong British presence through their office in UK managed by Martin Green and Tony Harris. Sensortechnics was sold to Augusta, GmbH in 1998. Augusta is a holding company located in Frankfort, Germany.
Sensortechnics is under the management of Josef Oettl. Most of the key people still remain with the company. They on their way to becoming one of the largest sensor companies in Europe. Sensymtonics France In France, Sensortechnics had an employee, John Claude Bord, who I had worked with when he was a field applications engineer at National Semiconductor in the seventies. JC Bord started Sensymtronic. While at Sensym I approved the use of the name and we agreed they would work with Sensortechnics in the same manner of mutual exclusivity for Sensym products as Sensortechnics.
Sensymtronic was acquired by Data Instruments in 1997. It has been closed by Honeywell after the DI acquisition. The key employees has started a new company, All Sensors France. SensoNor Norway A nice little silicon fab and micromachining operation about an hour drive from Oslo. They seem to have the their best success in accelerometers for automotive applications. I can’t imagine how they can compete with the high social costs inherent to Norway companies. Siemens Nurnberg Germany Even before the acquisition of the Bendix Sensor Research Group Siemens had the largest, non government sensor research group in the world.
They have the capability to research any sensor concept that has been published and have probably done so for most. Yet their only commercial effort, a pressure sensor, was unsuccessful. While Siemens enjoys success in automotive and medical markets this success has not translated to marketable sensor products. Vaisala Vaisala’s accelerometer product line was purchased by Art Zias for Breed Automotive. Vaisala has worked on silicon based variable capacitance sensors for about twenty years. They use a pyrex clad silicon-silicon-pyrex sandwich that provide variable capacitance transducer with characteristics as though they were made entirely of ilicon. They may be making the best low pressure sensors in the world today. They are competitive with Dresser X-Fab, Erfurt, Germany A company with ties to a company in the Netherlands. This is another former Eastern Block com- 28 sensor history pany. It has a crude silicon sensor capability. 29 all sensors Significant Applications In the history of the silicon based sensor business there have been only four significant applications based upon generating significant sales by serving a single application. The word “significant” being defined as generating, or will generate, in excess of over one hundred million dollars sales revenue.
The number one sales generating application is manifold absolute pressure sensors. This application has generated in excess of one billion in sales. The next application, having generated several hundred million in sales, is blood pressure. The third application is crash sensors for automotive air bag applications. The fourth is the newest application is automotive fuel vapor sensing. This application has not yet generated over a hundred million in sales but will in the near future. Disposable Blood Pressure This is an application that several people in the industry take credit for having created.
The history is as follows. In 1977 a representative of American Hospital Supply (AHS) approached National Semiconductor for a $5. 00 disposable pressure sensor and was sent away for such a fool hardly request. The market for such a device, at the time, was in the twenty dollar plus range. AHS continued their work and the first successful disposable BP sensor appear in 1979 manufacture for AHS by Gould. It used a silicon gage with a mechanical force concentrator. The first true MEMS disposable sensor appeared on the market in 1980 and was sold by Cobe Labs in kit form for $30. 0 and used a Honeywell sensor. A very nice baby blue package with a matching cable and connector designed by Steve Hanlon at Cobe. The first high volume, low cost sensors was manufactured by Spectramed and designed by Buzz Moran. By the early eighties the Spectramed devices was the market leader. In the early eighties Sorenson, now Abbott Critical Care, under the direction of Harlow Christenson, started making inroads in the market using sensor die purchased from several Silicon Valley companies and incorporating them into their package. Today, Abbott owns about eighty percent of this market.
Utah Medical, owned and operated by Dean Walters, entered the market in the mid eighties with an approach similar to Abbott and is now the second largest producer in this market. Others that have participated include: Graphics Controls, Deseret (now Warner-Lambert), Medex, and Healthdyne. All these companies have similar designs tailored to meet a specific market need. This market developed as follows. In the early eighties the majority of the market used reusable transducers with disposable dooms. This require sterilization and replacement of the doom.
The disposable was sold as a lower cost solution. Only to be lower cost require a bit of imagination for the hospitals to buy. DRG’s, Diagnostic Review Groups, imposed on the hospitals in the early eighties drove all disposable applications. Under DRG’s costs for disposable could be recovered from patients but fixed costs could not. In the late eighties DRG’s were replaced to a large extent by procedural costs. Meaning a hospital got so much money for a procedure and it did not matter what their costs were. This look like it would cut the market for disposable and resurrect the reusable market.
However, another variable, AIDS appeared and anything touching blood needed to be disposable. Thus any medical 30 sensor history procedure where the patient is anesthetized will have from one to three disposable blood pressure sensors. 31 all sensors The Millionaires Club Some people have managed to make a significant amount of money in the sensor business. Since there seems to be a general fascination for knowing who has been financially very successful I have devoted a section to identifying those I am aware of that have made a little money in the sensor business.
With all the companies Art Zias has been responsible for starting or being in the sensor business I am not sure that he would qualify for membership to the club except for the fact that his wife, Ellie, probably does as she has been very successful selling real estate in the Valley for many years. Therefore, Art may qualify on the strength of her efforts. The most financially successful individual in the sensor industry is not in the silicon side of the business but has accumulated so much wealth from the industry that I had to mention him as he is most probably the only one in the over hundred million dollar category.
The person is Fred Kavli, of Kavlico. Kavlico manufactures ceramic variable capacitance pressure sensors and is noted above as a recent entry into silicon based sensors. Persons in the ten million dollar plus category would include; Ed Colbert, founder of Data Instruments, John Easton, president and founder of Sensotec, Helmut Gutgesell of Sensortechnics Gmbh, Don Lynam founder of ICT and IC Sensors Tony Kurtz of Kulite and Hans Keller. Members of the single digit million dollar club would include; Janusz Bryzek, Joe Mallon, Kurt Peterson, Jim Knutti, Henry Allen, and Rick Schaffzin. 2 sensor history Some People to Remember There have been some people that have passed away that deserve mentioning. If for no other reason than to just be remembered, for someday this will also be our legacy to those that follow. I mentioned Ray Pitts and his contribution with the National Semiconductor/Sensym Transducer Handbook. In the dedication to the 1977 Handbook the dedication reads “This book is dedicated to the man whose endeavors made it possible, but who will not see it in print- Richard J. Billette. Dick work
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