Series of Events Makes Thin Film Resistors More Affordable:

Current Ruthenium Price: 2008

Since January of 2008, the price of ruthenium has come down to approximately $300 per Troy ounce, but this is still six times higher than the historical average. Therefore, resistor manufacturers and their customers are looking to the playbook for ceramic chip capacitors who faced similar volatility in raw material prices (palladium) in 1995 and again in 2000. Then successfully displaced palladium bearing electrodes over time in many MLCC applications with the lower cost, and more stable nickel based electrode powders and pastes.

In thick film chip resistors, the new trend is also to use nickel based resistive metals instead of ruthenium to distance manufacturers from the volatility of precious metal pricing going forward. The result has been new innovations in mass production of thin film resistors using advanced, rapid sputtering processes.

What Thin Films are Currently Being Used:

Thin film resistors have been around for almost 25 years, and have been historically based upon nickel-chromium, tantalum nitride, chrome silicide or hafnium diboride metal solutions. Traditionally, a thin film resistor solution has been more costly than a thick film solution because of the slow production process; however, in 2008, due to higher precious metal costs and innovation in the mass production process for thin film resistors, the costs associated with thin film resistors have plummeted, making them on par with, and in fact sometimes more cost effective than their thick film counterparts. Many companies are taking notice.

More and More Nickel Chromium Designs:

The new batch of thin film resistor production that has come on line worldwide between 2006 and 2008 have largely been based upon nickel chromium sputtered designs. The resulting chips are almost identical in appearance and footprint design to thick film resistor chips, which makes them easily surface mountable in today’s advanced pick and place machines. To keep costs low, the substrate of a thin film resistor is typically 96% alumina ceramic, the resistive layer is a sputtered nickel-chromium superalloy, the electrode is copper, the overcoat is epoxy, and the solder layer is nickel and tin. This combination of materials produces a resistive chip that offers extremely tight resistive tolerances while maintaining a ‘green technology standard.” Thin film resistor manufacturers in China are quick to point out that in addition to displacing expensive precious metals in the design, they have also displaced the electronic glass consumed in the protection layer. Since the electronic glass contains lead (pb), the thin film chips are in fact a more environmentally sound solution for the customer.

Thin Film Market Development: First Hand Experience

When I first studied thin film resistive solutions back in 1993, the customer base was entirely specialized, and focused on defense, medical implant and oilwell probe assemblies. This remained unchanged until 1998 because no other segments could justify the costs associated with using thin film resistors- but the tight tolerances, advanced heat dissipation, extreme low current noise and, anti-sulfer features of the chips were required for the harsh environments of the specialty high technology market segment. In 2000, thin film solutions, based upon their advanced performance criteria began to make an appearance in computer servers, telecommunications infrastructure equipment and local area network designs, but still in only small quantities as prices for these early thin film designs were as high as $3.80 and were exotic solutions to specialized problems. After repeated trips to China and Korea in the late 1990s and 2000’s I was asked for advisement for mass commercialization of thin film technology; and the number of requests began to grow exponentially from 2006 through 2008. I was first approached by a major datacommunications equipment company who wanted my help with finding every single production program for thin film resistor chips in the world (trade and academic) to see if designing in thin film resistors for mass production was feasible. One primary conclusion from this specific exercise was that if a new sputtering line was developed, one that was “in-line” sputtering, it could revolutionize the industry.

Overcoming Mass Production Requirements for Mass Market Competition:

The critical elements in thin film technology, the ceramics, metals and pastes had always been available, and the sputtering equipment required can be 40 years old and still turn out a perfect thin film resistor, but the problem was always mass production. If you look at the modern screen printing process for THICK film chips, the disconnect between the two markets comes in the form of mass production. Thus the conclusion has always been a mass sputtering solution, which is not easy to do because it elevates the equipment requirements from low volume batch production, to massive scale production. Sputtering equipment is not designed to serve a 1 trillion piece market, so the answer has always been mass production of thin film designs to cut prices and compete with thick film chip resistors. The raw material price increases for thick film materials, coupled with new developments in mass production of thin film resistors, has sped up the time process by which thin film chips become more cost effective.

Current Status:2008

In 2008 we note that demand for thin film chip resistors is now making inroads into the higher volume segments of the marketplace, especially in automotive sub-assemblies (for its anti-corrosion feature); consumer audio and video ports because of its low noise feature, into notebook computers, DC/DC converters and base station access equipment because of its advanced heat dissipation and low TCR.

Outlook to 2013

Thin film chip resistors are expected to make further inroads into higher volume electronics between 2008 and 2013, including wireless handsets, game consoles, portable MP3 players and residential HDTV sets and home theatre equipment. Paumanok expects mass production of thin film resistors in China over the next five years, and for the market to become increasingly more competitive as more manufacturers develop mass production sputtering processes for thin film chip resistors. The market will most probably grow in terms of the number of available case sizes, power handling capabilities, voltage ratings and tolerances; as it begins to displace thick film solutions in increasingly larger numbers.