Robust materials are absolutely vital
Plansee has been supplying the electronics industry for more than 90 years. Over the course of time, the applications have shifted from the analog world to the digital world.
In the 1920s, electron tubes were among the first applications in the nascent electronics industry for which Plansee supplied molybdenum and tungsten components. These tubes were needed primarily in radio and wireless engineering. And right up to the 80s, these robust tubes were crucial in transmitting phone conversations, for radio link systems, in UHF or television transmitters or in satellite ground stations. The high power output requirements for these tubes demanded materials that retained their electrical conductivity, strength and dimensional stability at the extremely high operating temperatures involved and which had a low coefficient of thermal expansion and a low vapor pressure.
From tubes to semiconductors
As of the 70s, molybdenum, tungsten and tantalum were in increasing demand in the form of thermal management components in power electronics and semiconductor fabrication. And to this day, material properties such as excellent thermal conductivity, a tailored coefficient of thermal expansion and a high degree of purity deliver a long service life in electrical equipment, where such materials are used in semiconductor base plates, heat sinks or heat spreaders.
At first glance, the fact that electrical components generate heat would not seem to be anything to worry about. But because the transfer of heat can also be expressed as heat flux per surface area (heat flux density), the heat flux density in many components is actually extremely high, sometimes reaching values comparable to those of a rocket engine at around 2800 °C. The coefficient of thermal expansion is another critical factor for all semiconductors. If the semiconductor and the underlying material expand at different rates when exposed to changes in temperature then mechanical stresses arise. These may damage the semiconductor or impair the connection between the chip and the heat spreader. Plansee’s materials have the optimum coefficient of thermal expansion for joining semiconductors and ceramics. Plansee’s semiconductor base plates can nowadays be found in wind turbines, trains and large-scale production plant. Or in semiconductor power modules for inverters (thyristors) and power diodes, for example As the substrate for the sensitive silicon semiconductor, they ensure a module service life of over 30 years. Various coatings also protect Plansee’s materials against corrosion and improve the solder connection to the semiconductor.
From tube TVs to flatscreens
In the 80s and 90s, as the technology behind CRT color TVs had fully matured, Japan began to see the development of the upcoming flatscreen industry. And from the word go, Plansee was an important supplier, engaging in the development, manufacture and ongoing optimization of sputtering targets. Sputtering targets are coating materials made from molybdenum, tungsten
and other alloys, and still provide vital functional layers in thin-film transistors in TFT-LCD screens. These provide instantaneous control of the individual image dots (pixels) and consequently ensure sharp image quality. Plansee has established complex supply chains for the production of these sputtering targets, and has a complete mastery of all the steps involved in the process: Every sputtering target is manufactured in its entirety by Plansee. The tungsten and molybdenum producers GTP and Molymet ensure supplies of these coating materials over the long term. The coatings experts at Plansee are in constant and close contact with universities and research establishments and use their knowledge of products and applications to support the development of customer applications in Asia and across the globe.