Polyphenylene Ether Enables Low Dielectric Photosensitive Acrylate Resins with Enhanced Mechanical Properties for UV‐Assisted Direct Ink Writing

Additive manufacturing has emerged as a transformative technology for manufacturing high-frequency printed circuit boards. Acrylate-based photosensitive resins are widely employed in such processes owing to their fast-curing speed and high printing precision. However, acrylate-based systems still present considerable challenges for 3D-printed circuits, mainly due to inherent drawbacks including inadequate toughness, low tensile strength, and high dielectric loss. Herein, polyphenylene ether (PPO)-modified acrylate photosensitive resins are designed and prepared to tackle these issues. The introduction of PPO endows the inks with pronounced shear-thinning behavior and rapid thixotropic recovery, thus facilitating smooth extrusion and high-fidelity direct ink writing. The optimized formulations exhibit remarkably enhanced tensile properties with tensile strength increased from 28 to 74 MPa, while elongation at break rises from 2.7% to 8.8%. The dielectric constant and loss decrease from 3.06 to 2.53 and 0.016 to 0.012 at 5 GHz, respectively, accompanied by reduced water absorption from 1.74% to 1.39%. These results demonstrate that PPO serves as an effective modifier that overcomes the inherent drawbacks of conventional UV-curing acrylate resins. Overall, this study offers a promising strategy for developing photosensitive inks for 3D printing and additive manufacturing technologies.