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The recent publication of IPC’s 2018 PCB Technology Trends study highlighted several significant trends that will impact the board fabricator going forward over the next five years.
Some of the most significant technology trends I see are in the materials segment. We all recognize that laminate materials are the substrates on which circuit boards are built. However, these materials perform critical multiple functions in an interconnect device. Important attributes such as signal integrity, impedance, frequency, and ability to withstand high soldering and operating temperatures are just a few.
The 2018 survey results indicated the need for speed and low loss as critical functions of the materials chosen. This is the digital age, and with the Internet of Things, virtual and augmented reality, vehicle-to-vehicle communication, etc., the need for low-loss and ultra-low-loss materials continues to grow as a percentage of circuit boards fabricated. The OEMs’ responses suggested that applications for frequencies greater than 20 GHz will almost double by 2023 over 2018. Indeed, there is a small group of OEMs pushing 77 GHz currently. There is discussion that over the next 5-8 years we will see 100 GHz. The survey results also showed a significant uptick in the use and specification of liquid crystal polymer (LCP), PTFE and ceramic-filled materials in order to support the need for higher operating frequencies.
These materials must not only provide enhanced electrical properties, but must also provide higher reliability against thermal decomposition, operating temperature extremes, and more operating cycles per day. These issues place significant pressure on the material performance. Temperature of decomposition (Td) is assuming more importance going into 2023. As major OEMs continue to push lead-free assembly and require improvements in long-term reliability, thermal decomposition of materials become a significant influence. There is a growing need for Td greater than 340°C.
These trends are significant and will require a change in the way PCB fabricators approach processes used to fabricate these circuit boards. Changes will be required in interlayer processing, lamination equipment and parameters, surface preparation and metalization. These higher performance materials become more difficult to process chemically. Thus, operating windows and the need for improved process controls becomes paramount moving into 2023 and beyond.