Aerosol Jet Printing of Benzocyclobutene as a Thermally Stable, Low‐Loss Dielectric for Multilayer Microwave Electronics

Dielectric materials pose a key constraint for the fabrication of complex and high‐performance printed electronics, with low‐loss dielectrics particularly important for high‐frequency applications. Here, aerosol jet printing of a benzocyclobutene‐based resin is demonstrated to support low dielectric loss, high thermal stability, stable and versatile print capability, and robust process and operational compatibility with printed conductors. This suite of characteristics is enabled by tailored ink formulation for rheological and drying properties, in‐line drying controls during printing to mitigate overspray, and refined post‐processing and characterization methodologies. Together, this enables stable printing over a wide process parameter window to achieve line width as low as 30 µm, minimal overspray, and effective leveling for smooth and dense films. The printed dielectric exhibits a degradation temperature >400°C, supporting integration with printed conductors for multilayer structures featuring excellent thermal stability even under extended thermal cycling. Moreover, dielectric characterization at 32–40 GHz using a resonant measurement configuration reveals a complex relative permittivity of 2.53–j0.004, corresponding to a low loss tangent of ∼0.002. This suite of dielectric, thermal, chemical, and process characteristics supports a compelling candidate for advanced manufacturing in microelectronics packaging, wireless communication, and sensing.