BTU Europe Ltd, Farnborough, Hampshire, England

Citation

Cullen, L. (1999), "BTU Europe Ltd, Farnborough, Hampshire, England", Soldering & Surface Mount Technology, Vol. 11 No. 1. https://doi.org/10.1108/ssmt.1999.21911aaf.001

BTU Europe Ltd, Farnborough, Hampshire, England

BTU Europe Ltd, Farnborough, Hampshire, England

Keywords BTU, Thermal processing

Setting the scene

Situated in Hampshire approximately 30 miles from London, Farnborough is possibly best known for its International Air Show, which takes place every two years in the first week of September. The town itself owes much of its importance to the development of the Royal Aircraft Establishment. A short distance from the M3 motorway, connecting with the arterial, if slow-moving, M25, is the Southwood Summit Centre, a modern business park, and home to BTU Europe.

BTU Europe is part of the network of sales and service offices maintained by BTU International throughout the USA, Europe and the Far East, supported by a distribution network of representatives and sales agents worldwide. BTU International ranks as a global leader in the design and manufacture of thermal processing systems, and sees itself as a key provider of thermal process solutions.

Taking a quick glance at BTU's early history, the company, headquartered at North Billerica outside Boston, Massachusetts, was established in 1950 by Howard Beck, a Polish émigré to the USA after the Second World War. The company was created to develop diffusion furnaces for the thin film industry, but quickly broadened its horizons to include conveyor furnaces. By 1960 BTU had become a key manufacturer of furnaces for the thick film and microelectronics industry. Paul Van Der Wansem, the current CEO and principal shareholder, acquired the company in 1981. Under Paul's leadership the company's product range has grown to include ovens and furnaces designed for semiconductor packaging, electronics manufacturing, firing of ceramics, heat treating and brazing of metals, sintering of ceramics, thin film chemical vapour deposition, reactors for photovoltaic cells and flat panel display applications, and high temperature sintering furnaces for the nuclear fuels industry.

Facts and figures

BTU International engages more than 400 employees worldwide, 15 of whom are based at the BTU Europe facility at Farnborough, which, in addition to European sales activities, offers customer support, technical support and field service. European operations are led by Peter Franklin, who hosted Soldering & Surface Mount Technology's recent visit to the company (Plate 1). After 15 years with BTU including four years as European sales manager, Peter was appointed managing director of BTU Europe in 1996, and is pleased to record that the company's revenue and profitability, including market share, have increased each year since then. Particularly pleasing has been the addition in 1998 of five major Japanese manufacturing companies in Europe to the BTU Europe customer list.

The global sales figures for BTU International in 1997 totalled $60 million, of which $12 million was achieved by BTU Europe. Looking at business worldwide, a characteristic breakdown is 50 percent USA, 25 percent Europe, and 25 percent Asia. In terms of client base, the company supplies to all of the leading electronics subcontractors and OEMs in the world. In Europe, the 1998 sales figures continue to reflect a strong UK and Ireland presence, with increased market penetration in France, Scandinavia, Italy and Germany.

Plate 1Peter Franklin, managing director ­ BTU Europe

Product overview

The diversity of applications served by BTU's range of standard and customised equipment includes: surface mount reflow soldering, flip chip and COB soldering, firing of thick film hybrids, polymer thick film curing, processing of multichip modules, integrated circuit packaging, thin film deposition processing using APCVD (atmospheric pressure chemical vapour deposition), ceramic metallisation, brazing and other custom high temperature processes such as nuclear fuels sintering and the cofiring of ceramics.

BTU products fall into four main categories. First, continuous thermal processing systems, which operate at temperatures ranging from 150°C to 1,200°C in atmosphere from oxidising to reducing. Applications include semiconductor packaging and hybrid circuit manufacturing. These systems vary in unit lengths, number of processing zones, and conveyor belt widths.

Second, high temperature systems, which comprise walking beam and special batch mode systems for high temperature processing up to 2,000°C and heavy product loads. These systems are used for sintering multilayer integrated circuit packages, technical ceramics, nuclear fuels, refractory metals, and powdered metals.

The third category, atmospheric pressure chemical vapour deposition (APCVD) systems, deposit thin film on a variety of substrates. Applications include the manufacture of photovoltaics, optoelectronic devices, electrochromics, and architectural glass.

Finally, in 1989, BTU entered the reflow solder market to provide reflow solder system lines for attaching surface mount devices and curing adhesives on high-density printed circuit boards. The company's first solder reflow oven incorporated mixed technology (infra-red and convection). In 1991 it manufactured its first full convection oven, which accounted for 6 percent of business in that year. By 1993, a mere two years later, the system accounted for 43 percent of BTU's business. Today, the company still reports that the bulk of its business is in reflow solder systems; 58-63 percent of sales result from SMT and related business. However, it should not be overlooked that BTU remains a global leader in thick film technology, is the largest supplier of APCVD systems to the photovoltaic industry, and the major supplier of walking beam systems to the nuclear fuel industry.

Product focus

The products of greatest relevance to Soldering & Surface Mount Technology will be profiled in more detail, with particular mention given to special features of these thermal processing systems.

VIP series of reflow solder systems

The VIP series aims to provide leading-edge performance at a low cost of ownership. With a maximum temperature rating of 300°C, they are used for reflow soldering of surface mount components including BGA, MCM, COB, flip chip and DCA, and for semiconductor packaging applications such as encapsulation and the curing of adhesives and conformal coatings. The series comprises five models designed to meet the needs of OEM and contract manufacturers, depending on their volume and the desired features. The VIP series includes: VIP70A, VIP98A, VIP70N, VIP98N, VIP148A, where "A" and "N" designate the atmosphere (air or nitrogen), while the numbers indicate the heated length of the unit.

Paragon series

Although designed for the same applications as the VIP series, the more advanced de-luxe Paragon series introduced some 18 months ago has a maximum temperature rating of 325°C (400°C optional), and is distinguished by its powerful 5kW heaters, which provide the fastest temperature response available in a thermal processing system. The excellent thermal performance of this line has been proven in a series of evaluations in 1997 and 1998.

The Paragon series is available in three models: the Paragon 70, 98 and 150. The systems feature forced impingement convection with side-to-side recirculation, self-contained heating modules for easy servicing, and remote diagnostics. These areas are designed to the highest volume production capability with minimal maintenance requirement.

It was interesting to learn that the Paragon 150 is widely used for "intrusive reflow" or through-hole reflow, where the system's superior thermal transfer properties are ideal for this process, which is not easy to carry out efficiently. Also of interest was the revelation that a colleague at BTU Europe had developed "intrusive reflow" technology as a replacement for wave soldering when, for example, less than 10 percent of the soldering on a board involves through-hole components. Problems such as those arising with through-hole connectors are readily solved using the Paragon system.

With respect to gas consumption ­ an important aspect for users (and a selling point for system manufacturers!) ­ it was confirmed that, in both the VIP and Paragon series, the proprietary gas-saving systems at the entry and exit of the equipment can reduce gas consumption by 50 percent.

Special features

Forced impingement convectionIn its ranges of thermal processing systems for the surface mount industry, notably the VIP and Paragon series, an important feature is the use of forced impingement convection. This technique enhances conventional convection heating by directing heated gas to board surfaces faster and with optimum force to achieve efficient and consistent heat transfer. The main advantages claimed by BTU for its proprietary gasflow design include minimised transfer of gas from chamber to chamber, improved temperature control, more uniform heating and, ultimately, higher production yields.

Flux management systemIn the surface mount industry, the effects of flux residue are well known, and the problem has become even more acute with the emergence of no-clean and low-residue pastes. Although these advanced formulations may mean that a board being reflowed does not require cleaning afterwards, they also mean that flux residue has most probably accumulated in the reflow oven process chamber. Addressing this problem, BTU's reflow ovens are available with an innovative flux management system that minimises the collection of flux residue in the process chamber and cooling section by as much as 90 percent (by weight) (Plate 2). This reduces downtime considerably, and significantly fewer pollutants are released into the atmosphere in the exhaust gas.

The present second-generation flux management system consists of a condensing unit with gas-to-water heat exchangers mounted in series inside the unit. The inlet on the unit is connected to the exhaust of the heating section. The hot vaporous gas exiting the heating section is drawn by a high-vacuum blower into the condensing unit and cooled by the heat exchangers (Plate 3). Droplets of residue formed by the cooling of the flux-laden gas are captured on the heat exchangers and by a series of filters through which the gas passes. Droplets which fall to the base of the condenser are collected in a removable drip tray. Another "plus" is that the flux management system also conserves processing gas. Once the cleaned gas exits the condensing unit, most of it is recirculated through the cooling unit, and back into the heating section of the oven for reuse. The system can be completely removed from the machine, allowing ease of access for cleaning.

Retractable centre support (RCS) systemFor the reflow engineer, heating double-sided PCBs and boards with high component density must be achieved without board warp or loss of components on the underside. Double-sided PCBs typically ride on edge rail conveyors rather than a mesh belt because of the presence of components on both sides, often resulting in the sagging of thin boards when heat is applied. To address this problem, BTU includes in its solder reflow systems a patented retractable centre support which accommodates boards of various widths and prevents sagging during the heating cycle. The RCS can be programmed for automatic adjustment of its vertical and horizontal positions. The dual-channel design and cross-support system provide stability throughout the length of the oven.

Plate 2BTU ­ flux management system

Discussion time

During Soldering & Surface Mount Technology's visit to BTU Europe, apart from familiarisation with the product range, there was the opportunity to discuss some aspects of the company's philosophy and operations. The following is a brief synthesis of this discussion.

Providing thermal process solutions

BTU has gained its position as a leading supplier of reflow systems by focusing on technological innovation in three main areas: temperature, atmosphere and process control. Clearly, these areas are crucial to the development and manufacture of thermal processing systems. However, the emphasis for 1998 has been on promoting the company as a provider of thermal process solutions. This reflects BTU's dedication to solving customer problems and achieving customer satisfaction. Many of the company's product developments have evolved from collaboration and dialogue with clients, including major names from the OEM and subcontracting industries. Much of the equipment manufactured is customised. In fact, BTU is driven to leading-edge technology by its major customers, who require the most advanced thermal process solutions for their applications.

On a more general level, the company's sales engineers are thoroughly trained and experienced in identifying the right system for a customer's requirements. An important component in BTU's building of customer relationships is the applications laboratory, where customers can develop process parameters by testing their products in a fully operational BTU system. These customer trials are welcomed, and serve as a useful third-party evaluation of the products. The company also offers a number of after-sales and customer support programmes including a 24 hour technical support line, field service, and training sessions. Customer training courses are held every two months, generally on maintenance, operation and processes, and customised courses are available on request. The network of representatives throughout Europe receive training as service engineers by BTU.

It was interesting to learn that, typically, field service engineers are occupied installing new equipment and spend almost no time on maintenance of existing systems ­ a good reflection on the quality of the systems, and on their ease and accessibility for maintenance by the client. For systems characteristically running 24 hours a day, seven days a week, this is highly important. The box frame design enables ready access to all of the electrics and mechanics of the systems.

In the UK, field support is provided from Farnborough, as well as from the sales and service offices in Livingston (Scotland) and Trowbridge (Wiltshire). Some $500,000 worth of spare parts are held at Farnborough.

Commitment to quality

Commitment to quality is implicit throughout BTU's operations. A total quality management (TQM) system is in place at North Billerica, and strict quality control is implemented at every step of manufacture. Efforts to guarantee quality extend to the fabrication of the company's own refractory insulation from proprietary formulae and materials, as well as a number of other specialty parts and assemblies used in their systems, such as atmosphere containment vessels, control devices, and thermocouples. The confidence placed in the reliability of their systems leads BTU to offer the most comprehensive warranty in the business. Advanced software is available for all lines of BTU systems, providing greater information management and operator flexibility, and featuring real-time data monitoring, upstream capabilities and remote diagnostics (Plate 4).

In terms of approvals and accreditations, BTU has ISO 9000 approval. Systems are manufactured to full SMEMA and Siemens compliancy.

Looking ahead

Asked about the future developments of the company and its product range, Peter Franklin was reluctant to disclose any secrets during the visit, apart from saying that the strategy team meets on a regular basis, including representatives from the USA, Asia-Pacific and Europe, to plan the short-, medium- and long-term strategies of the company, based characteristically on customer feedback. In terms of trends, he highlighted the shift from OEMs to subcontractors as customers. Increasing numbers of manufacturers are turning to subcontractors to carry out some of their production or assembly operations. BTU has benefited considerably from this trend, adding a number of prestigious subcontractors to its client base. One, in particular, starting from an initial machine order in 1993, has since installed up to 14 lines. Serving the subcontractor market does, however, place enormous pressure on delivery. The company is working hard to be flexible on delivery, and aims to continually reduce lead times.

Plate 3Blower plenum module from BTU

Plate 4BTU ­ Wingon™ software

Conclusion

At the turn of the century, BTU will celebrate 50 years at the forefront of technology in designing and building continuous ovens and furnaces. The company's entry some ten years ago into the surface mount technology arena has proved dramatic and successful. Inevitably there will be ongoing demands for greater sophistication and ever more precise control over the reflow process. BTU's guiding philosophy is to meet or exceed the precise process requirements of the customer. Undoubtedly this quality-driven and customer-led company will continue to deliver innovative thermal process solutions that will guarantee system reliability and prolonged uptime, for as long as process requirements continue to evolve.

Lorna Cullen