Power electronics are not just for industrial applications anymore.

When most of us think of power electronics, it usually is with a broad brush that often includes products in the industrial sector. For me, I previously put power electronics in the category with anything that included a motor or actuator that had to be moved. But, admittedly, my view has changed over the years. In fact, when you start to delve into true power electronics, the influence of power devices is applicable to several market sectors. Industrial is, of course, part of the power electronics landscape, but so are applications in the automotive, LED lighting and photovoltaics/solar markets. The definition of power electronics is “the application of solid state electronics for the control and conversion of electrical power.” In short, wherever there is a need to alter voltage, current or frequency, you will find power electronics.

What does this have to do with printing? At their core, all the materials deposition processes in each of these power applications involve modern printing techniques. But, the printing requirements and priorities for each market application are undeniably distinct. Here, we’ll take a look at each and analyze the best printing solutions for each.

Industrial. The industrial market is commonly associated with power electronics and is quite diverse, encompassing everything from manufacturing automation to air conditioning and refrigeration. Within this sector, the primary requirements for electronics manufacturing are safety and reliability. Take the petrochemical or nuclear industries, for example, where any failures could be life-threatening, and it is understandable just why safety and reliability top the list of requirements. With industrial, the printing process must be highly accurate, repeatable and reliable. Tools should keep the process in check, and paste height monitors should ensure accurate volumes of material are constantly available.

Automotive. It’s no secret that the electronics content of automobiles has grown exponentially over the past half-century, with the electronics value of a vehicle currently at about 30% (up from 5% in the 1950s-’60s). Of course, not all of this is power electronics; much is attributed to comfort and entertainment. Automotive power electronics of late has largely been driven by improved fuel efficiency. Many devices used in these applications see highly miniaturized components next to large transistors and are often found very close to the engine. Automotive power electronics demands printing capabilities that can manage miniaturization, end-use in harsh environments, higher run rates and safety. And, all this has to be produced cost-effectively. Printing technologies that can accommodate highly miniaturized devices alongside larger components – systems such as improved paste transfer squeegees, stencil coatings and enclosed head squeegees – are all important tools here. New solder paste materials that can withstand higher temperatures are also a key part of an effective solution for power electronics in this sector.

LED lighting. There has been ample effort both by government entities and environmental groups to replace incandescent light bulbs with low-energy bulbs. Many of the low-energy bulbs – or compact fluorescent lamps (CFLs) – are starting to lose favor in the market, however, due to their mercury content. LED lighting is likely the most logical low-energy replacement, and, yes, LEDs do involve power electronics in which high-voltage AC is converted to low-voltage DC. To address power efficiency requirements, new surface mount technology devices have been designed and, in the future, will lend themselves to traditional SMT printing processes where high-speed, high-throughput print capabilities will be tantamount.

PV/solar. This is certainly an area where our company has quite a bit of expertise, specifically at the c-Si cell level, where print speed and accuracy are critical. Solar cell printing techniques we’ve developed such as Print-on-Print have helped boost efficiency levels, and now there is the potential for even more efficient solar modules. A new development – the micro inverter – is essentially a mini-inverter for each module (as opposed to a single inverter for the entire system) and permits greater efficiency compared with the traditional central inverter technique. Micro inverters contain a fair number of SMT devices and require high-speed, accurate printing technology to ensure maximum power efficiency conversion.

Each sector and application for power electronics has distinct printing requirements. Whether it’s addressing reliability for safety regulations, speed for high-volume manufacturing, new innovations for ensuring robust transfer efficiency with fine-pitch and heterogeneous assemblies or next-generation dynamic process control technologies, advanced screen printing capabilities will be instrumental in progressing power electronics in all these unique market segments.

Clive Ashmore is global applied process engineering manager at DEK International (dek.com); This e-mail address is being protected from spambots. You need JavaScript enabled to view it . His column appears bimonthly.