Speaker Interview: Michael Hill, Technical Director, Research and Development, Skyworks Solutions, Inc.
In this speaker interview, we spoke to Dr. Michael Hill, technical director of research and development at Skyworks Solutions about the trends driving the advanced ceramics industry and the potential for electroceramics in future technology.
Dr. Hill received his Bachelor of Science (BS) degree in materials engineering from Virginia Tech in 1986. He received a Master’s Degree in materials science and engineering from Virginia Tech in 1988. From 1989 until 1996, Dr. Hill worked at the National Institute of Standards and Technology (NIST), where his work focused on the crystal chemistry of high-Tc superconductors and the synthesis of lead-based perovskites. In 1996, he received a PhD in materials science and engineering from the University of Maryland. That same year, Dr. Hill joined the R&D department of Trans-Tech, where his work focused on new formulations for microwave dielectric and magnetic materials as well as specialty advanced materials including thermal barrier coatings and solid-oxide fuel cells. In 2007, he was promoted to technical director of the R&D group at Trans-Tech. In this capacity, Dr. Hill is responsible for developing or overseeing the development of all new formulations at Trans-Tech.
Please tell us about your role as technical director at Skyworks. What are your key focus areas and responsibilities?
I am primarily responsible for creating formulations for new materials to support our various product lines, including oxide-based dielectric and magnetics. This often requires making compositional modifications or firing profile adjustments to current materials, as well as developing new ones. In my experience, inventing the material or adjusting the formulation is the relatively easy part. Defining the process to predictably manufacture thousands or even millions of parts out of this material is the difficult part. Fortunately, I am part of an excellent engineering team that collaborates to get this done.
My role also entails applications engineering, where I meet directly with customers to provide a solution to their ceramic material requirements. In many cases, customers have specific formulations they would like to investigate for their R&D effort, so we perform custom synthesis work.
What excites and challenges you about your work?
Every day at Skyworks is different and provides me with the opportunity to work with an extremely wide array of products involving oxide-based ceramic materials. It is satisfying to create a concept for an interesting material then synthesize, form, and fire it into a ceramic with the relevant properties measured in the facility. Our dynamic production team includes laboratory technicians and process engineers who are extremely skilled at measuring properties of materials. I also enjoy interfacing with customers to see how the material fits into their overall technology roadmap and in some cases, how it affects the entire market. With more than 20 years at Skyworks, I am amazed at how the needs for wireless communications in our market have evolved.
What markets do you serve and what are the megatrends and future technologies?
Within Skyworks’ RF ceramics business, our largest market is commercial wireless communications, particularly given the huge increase in demand for reliable wireless data transmission at extremely fast rates. The demand is not only for smartphones, but also for Internet of Things (IoT) devices that communicate with each other over wireless networks. IoT applications include smart homes and self-driving automobiles, among others. Our second-largest market is aerospace, where we supply feedstock for the production of thermal barrier coatings on jet engines or industrial gas turbines. In addition, our products go into diverse markets such as medical, military, and energy.
“I foresee a day when materials are selected computationally, then individually synthesized rather than making a whole series of samples in a lab and evaluating properties and repeating the iteration”
What opportunities do you see for future materials and electroceramic materials?
The advent of 5G is a revolutionary change in commercial wireless technology, particularly for millimeter wave applications (20-80 GHz). There is plenty of spectrum available at these frequencies; however, signal range is considerably shortened, which leads to new concepts for deploying wireless infrastructure. The materials required for use at these frequencies are likely to be very different than those employed in 4G or older technologies.
Another area of extensive research worldwide is in lead-free piezoelectrics. Piezoelectric materials are used in everything from shock igniters on gas grills to energy harvesters in hybrid electric cars. Those with the best properties contain toxic lead, so there is a movement to develop piezoelectric materials that are lead free.
Finally, there are some very exciting developments in battery technology, with many researchers working on lithium batteries with solid electrolytes. Not only does this improve the energy density of the battery, but it also prevents the thermal runaway issues experienced with batteries containing liquid electrolytes.
“There are numerous advances in battery and energy storage technology which, along with solid-oxide fuel cells, may push ceramics into the electric vehicle and clean energy markets”
What are the current material challenges that these applications are facing?
For millimeter wave materials in 5G, high frequencies will require dielectric materials that are temperature stable and have extremely low dielectric loss tangents. In addition, since the device size scales with the dielectric constant of the material and the frequency of operation, there is a need for temperature-stable dielectric materials with dielectric constants below 10 and very low loss tangents. For these higher-frequency device architectures, it is necessary to integrate numerous components into a module, which provides technical challenges. For the lead-free piezoelectrics, it is very difficult to find a good replacement for lead containing PZT. Trivalent bismuth is isoelectronic with divalent lead (although non-toxic), but behaves very differently in terms of the compounds it forms and their piezoelectric properties. For the solid electrolyte lithium batteries, the challenge is scaling up the manufacture of some existing novel chemistries and devices to full production. In many cases and applications, a lack of materials with the desired properties may be the bottleneck in the realization of breakthrough technologies. This is why materials science is so important to technology development.
In terms of industry news, what development, announcement, or otherwise has stood out most to you in 2017?
There are a number of interesting technological advancements that are of interest to the synthesis of new materials. One of them is the development of cold sintering techniques that can produce ceramic bodies at temperatures less than 300°C. This can be useful in a number of areas, including low-temperature metallization of ceramics and integrating ceramics with polymers to obtain unique functional materials. There also continues to be advances made in forming techniques, such as 3D printing and additive manufacturing, which can be implemented for complex shapes. There are numerous advances in battery and energy storage technology which, along with solid-oxide fuel cells, may push ceramics into the electric vehicle and clean energy markets. Another fascinating area is the strides made with computational materials science and predicting properties of materials yet to be synthesized based on density functional theory and similar techniques. I foresee a day when materials are selected computationally, then individually synthesized rather than making a whole series of samples in a lab and evaluating properties and repeating the iteration.
We’re looking forward to seeing you at Ceramics Expo 2018. What are you most looking forward to at the show?
The ceramic exposition provides us with a great opportunity to meet with suppliers and customers to discuss new business, as well as to monitor trends in the ceramic industry as a whole. As an exhibitor, we are able to meet potential customers to discuss ways in which Skyworks can provide a material solution for their technical challenges. The presentations are also extremely educational, as they typically provide valuable technical information with a business perspective. It is also helpful to learn about the latest in ceramic processing and analytical equipment. The AACCM meetings and network activities provide further opportunities to meet colleagues from other ceramic manufacturing companies to discuss business-related, operational, and technical items.
Michael Hill will be speaking on May 2nd at 11am at the Ceramics Expo conference.