Feature: Thermal management


The foundation of electronics reliability I


By Scott Horton, VP of Marketing, Johanson Technology Tis level of precision is essential for


n military and aerospace systems, thin film patterned substrates serve as the foundation of some of the most critical electronic assemblies, including RF, microwave, millimetre wave and high-speed


digital circuits. Tese substrates are typically made


by depositing extremely thin layers of conductive and dielectric materials on bases built from materials like alumina, aluminium nitride, quartz, or certain high-performance titanates with various dielectric constants (k). Te goal is to create precise, stable


electrical pathways that improve electrical performance and increase reliability, even under extreme conditions such as fast temperature fluctuations, high vibration, exposure to radiation and long mission lifetimes where maintenance is difficult. An additional benefit is that thin-film circuits are oſten smaller and weigh less than other technologies, which is crucial for airborne and spaceborne systems.


electronics embedded in low earth orbit (LEO) satellites, drones, spaceborne communications, radar payloads, navigation systems and signal processing electronics, where even slight impedance or phase shiſt can degrade link quality, reduce antenna beam accuracy, or impair payload measurements.


Thin-film substrates Compared to thick film or regular printed circuit boards, thin film technology allows for extremely fine detail, oſten with lines and spaces just a few microns wide, which ensures that electrical performance is consistent across all parts. With accurate conductor line widths and spacings, designers can control the characteristic impedance of transmission lines, the coupling between RF traces, as well as manage thermal loads within RF circuits. At high frequencies, even a small change


in circuit trace width can affect impedance or detune a filter, so this level of control


30 September 2026 www.electronicsworld.co.uk


is crucial. It also makes it possible to fit more circuitry into a smaller space whilst minimising unwanted electrical effects. Tin-film substrates provide the stable,


high-precision electrical platform on which critical electronics are built. Tey allow complex circuits to be integrated in ways that minimise signal loss, maintain phase coherence and reduce noise – attributes that impact range, clarity and security of communications, and the accuracy and resolution of sensing systems.


Military and aerospace-grade versions Compared to commercial RF substrates, those for military and aerospace applications are made to tighter dimensional tolerances and undergo more extensive screening. Tis includes controlling the dielectric constant, measuring conductor thickness to a micron precision, and stress testing for vibration, shock and thermal cycling. High-purity gold, platinum, or other


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