Vectron's Vision Of Frequency Control

Dec. 12, 2008
Vectron International is the worlds leading supplier of high-performance crystal oscillators, but is also a growing force in BAW and SAW products as well as in a wide range of sensors.

Southern New Hampshire is home to beautiful summers and snow-kissed winters. It is also home to the corporate headquarters for one of the world's leading crystal oscillator suppliers, Vectron International ( Part of the diversified Dover Electronic Technologies group of engineering and electronics companies, Vectron International also boasts expertise and manufacturing capabilities in sensors, surface-acoustic- wave (SAW) filters and oscillators, bulk-acoustic-wave (BAW) filters, and timing devices and modules of every size and description.

Vectron International is part of the $7 billion Dover Corporation ( group of companies. Dover's firms combine around the world to provide equipment, services, and solutions for industrial, fluid management, engineered systems, and electronic technologies markets. Although Dover has also grown through acquisitions, the firms management strives for organic growth, a philosophy that has resulted in fairly consistent 5-to-7-percent companywide year-over-year growth.

In addition to Vectron, Dover's group of companies includes Belvac Production Machinery (, Everett Charles Technologies (, OK International (, Knowles Electronics (, and the Ceramic Products Group, with Voltronics Corp. (, Dielectric Laboratories (, and Novacap, Inc. ( The Dover companies have realized a five-year compound annual growth rate (CAGR) of 17.9 percent in revenue and 25.3 percent in earnings from 2003 through 2007.

As part of the Dover "family," the current-day Vectron International can trace its history to 1985, when Dover acquired crystal oscillator house Oscillatek. In fairly rapid succession, Dover's management built its crystal oscillator and filter capabilities through the acquisition of Vectron Labs in 1992, AT&T's Frequency Control Products (FCP) group in 1995, and the German crystal filter company Telefilter in 1997. In support of marketing frequency control products worldwide, the Dover subsidiary Vectron International Technology Express (VITE) was established in 1998 to focus on selling highvolume, competitively priced crystals and crystal-based products worldwide. Dover added Cinox Crystal Company in 2000, the surface-acoustic-wave (SAW) fabrication facility of Temex in 2003, and the Corning Frequency Control (CFC) division of Corning, Inc. in 2004. The partnership with MEMS pioneer Discera was forged in 2006.

Even as part of the larger Dover group of companies, Vectron International itself has a number of different locations around the world, with corporate headquarters and oscillator and SAW design and manufacturing based in Hudson, NH. The largest facility is in Mt. Holly Springs, PA, with a 110,000-squarefoot operation for oscillator design and manufacturing. Crystal manufacturing is handled in Cincinnati, OH (the former Cinox), with oscillator and crystal design and manufacturing taking place in Neckarbischofsheim, Germany and SAW filter and MCF design and manufacturing in Teltow, Germany.

Although Vectron is probably most synonymous with crystals and crystal oscillators, the firm is considerably broader in its product lines, designing and manufacturing discrete and monolithic crystal filters, frequency translation, clock smoothing, and clock and data retiming circuits, timing modules, and sensors in addition to a wide array of crystal oscillators. The types of Vectron crystal oscillators are numerous, and include standard crystal oscillators, voltage-controlled crystal oscillators (VCXOs), temperature- compensated crystal oscillators (TCXOs), and oven-controlled crystal oscillators (OCXOs).

A recent visit to the Hudson, NH facility afforded the opportunity to see why Vectron International is a true world-class supplier of crystal oscillators and filters, along with SAW and BAW products. The location is home to a highyield wafer fabrication (fab) operation maintained to Class 100 cleanroom requirements (Fig. 1). The facility works with SAW wafers, using spin-coat methods to deposit resists and highresolution photolithography techniques to define device structures and features on the wafers. Each wafer yields about 1000 resonators or filters.

In addition to the SAW device production capabilities, the Hudson facility produces BAW devices in a Class 10,000 clean room operation using a base-plating process oven. The operation is based on a highfrequency- fundamental (HFF) ovenbased process for extended frequency performance of these BAW devices. The BAW filters and resonators can operate to about 250 MHz, creating a bridge between the fundamental-frequency coverage of the crystal-based devices and the frequency coverage possible with the SAW devices. In all cases, the facility relies on advanced automatictest- equipment (ATE) systems to speed the characterization of the crystal, BAW, and SAW devices before and after packaging. The facility boasts five full production lines for the crystal, BAW, and SAW products, each based on the same architecture so that shifts can be made in product production as needed to accommodate customer demand. For example, depending upon the needs of their customers, Vectron's Hudson facility can switch a BAW production line quickly to SAW production, to increase the total volume of those devices.

As with other Dover facilities, Vectron's Hudson locale is ISO 9001 certified (with some key locations also certified to ISO 14001 requirements). The facility has adopted lean manufacturing practices such as Kaizen and Six Sigma methods, all with an eye toward continuous facility and product improvement. The company follows a 16-point plan that has cut manufacturing cycle times in half compared to earlier attempts to reduce overall production times. The process starts with raw packaging, using tape-and-reel systems for precise automatic handling and placement of components and epoxy-based attachment of components within the packages (Fig. 2). The parts within the package are cured and then treated by a cleaner to prepare package and device surfaces for the addition of wire-bond connections. The packaged parts are placed in a gas environment prior to wire bonding.

In the case of crystal oscillators or filters, crystal resonators are epoxied to the package. The attached crystal and package are cured in a bake, and then the crystal is attached to the package, followed by a stabilization bake.

Of course, as exact as each crystal is cut and as robotically precise each crystal is placed within the package, frequency variations will occur from one packaged crystal to the next without some production tuning. This is accomplished by depositing small amounts of gold on the crystal electrodes while measuring the change in frequency by means of an automatic tuner system. The addition of gold serves to retard wave motion through the crystal, thus resulting in a slightly lower frequency. When it is necessary to raise the frequency following gold deposition, small amounts of gold can be etched away from the electrode, while the tuner system monitors the effect on the crystal's operating frequency. Additional high-performance tuning systems are also used with the SAW and BAW devices to adjust frequency and modify the pullability of the devices as required.

Once tuning is completed and the final frequency is reached for each product, packages are hermetically sealed using a multistep process. This process includes a bake to remove moisture to less than 50 PPM. Packages are sealed within a gas environment using a seam welder. Packaged devices are then exposed to an extreme environment, at high temperatures, to simulate worst-case conditions in a customer's application.

Package hermeticity is checked with a detection system, using a pressurized chamber filled with helium gas. For parts that are not hermetic, little or no deflection will be seen in the package lid. For parts with deflection in the package lids, the rate of deflection provides information on the quality of the package's hermeticity. Following the hermeticity test, parts that pass are laser marked with a date code and frequency information, followed by temperature testing from -40 to +85C or to a customer's specific requirements. Parts then undergo final testing to verify performance.

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Vectron International's stake in frequency- control technology and continuing improvement even extends to offering customers continuing education, in the form of a free, two-day course (which has actually varied in length from a single day to as long as five days) at the firm's Frequency Control University (FCU). Vectron's FCU is designed to provide both commercial and technical personnel with a comprehensive overview of the manufacturing process for crystals, crystal oscillators, crystal filters, SAW oscillators, and oscillatorbased modules. The focus is on product training, with Vectron's products used as examples, although the sales pitch is kept to a "dull roar." The training session is free and attendees are provided with reference materials. FCU courses are taught at the company's Hudson, NH and Mt. Holly Springs, PA facilities.

Although oscillators may be its bestknown products, Vectron International is also a growing presence in many sensor markets. Its SenGenuity product lines include fluid sensors, gas sensors, and physical sensors (such as motion detection). For example, the fluid sensors are often used as viscosity sensors to monitor the oil quality in fixed assets, such as power generators, compressors, or pumps. Vectron's engineers are currently working on adding capabilities to these sensors, such as measuring temperature and detecting the presence of water or gas. Using its BAW technology, the firm has developed a wireless temperature sensor that is totally passive, operating with power from the interrogator unit. The reliable sensor contains no moving parts and is already being used in commercial ovens throughout Europe. Much of the work on gas sensors is still at the research stage, although the company's experience in working with Discera (www. on microelectromechanical- systems (MEMS) technology for ruggedized oscillators (see Microwaves & RF, September 2008, p. 39) may pay off in terms of developing practical MEMS-based gas sensors.

Vectron International is well represented in commercial and industrial applications, and can be found in many military and space systems, including manned and unmanned space flights, Iridium low-earth-orbit-satellite (LEOS) communications systems, Globalstar satellite telephones, and the Mars Pathfinder. The company offers radiation tolerance of greater than 100 krad (Si) total dose and screening to MIL-PRF-55310, Class S or MIL-PRF-38534, Class K. Vectron International, 267 Lowell Rd., Hudson, NH 03051; (888) 328-7661, Internet:

About the Author

Jack Browne | Technical Contributor

Jack Browne, Technical Contributor, has worked in technical publishing for over 30 years. He managed the content and production of three technical journals while at the American Institute of Physics, including Medical Physics and the Journal of Vacuum Science & Technology. He has been a Publisher and Editor for Penton Media, started the firm’s Wireless Symposium & Exhibition trade show in 1993, and currently serves as Technical Contributor for that company's Microwaves & RF magazine. Browne, who holds a BS in Mathematics from City College of New York and BA degrees in English and Philosophy from Fordham University, is a member of the IEEE.

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