Ceramics are widely used as substrates for hard, high operating temperature applications for RF devices in defense radar and communications. Their high temperature handling and relatively high thermal conductivity, paired with potential to formulate for low-loss and high relative permittivity make them strong candidates for high speed, high heat hypersonic applications where signal loss is a premium, as well as high power devices that generate heat and devices where circuit miniaturization is needed.
Additive manufacturing of ceramics is quickly growing in sophistication. One method, using a photocurable polymer as a binder that is burned off during the sintering process, allows for very high-resolution features in the 3D printed parts. Complex shapes like smooth dishes or hollow cylinders with slotted irises printed in place are not only possible, but routine. Air/dielectric mixing structures, such as gyroids also become routine, allowing the designer to select any effective Dk within the bounds of the structure, from nearly that of air, to nearly that of the base Dk of the ceramic in question. This selectable effective Dk allows for dielectric-only impedance matching; rigid structures of very low effective Dk integrated with solid structures of high Dk; and focusing, dispersing, and steering lensing. Often these devices can be blended to form a superstrate that does multiple beamshaping functions, such as impedance matching and lensing, with a very low-Dk offsetting structure.
This presentation will review the DLP technology capable of printing these photocurable polymers with the heavy ceramic loading that are necessary to 3D print high resolution sintered ceramics. The DLP projection curing technology allows the machine to cure each layer of the print with one flash from the projector, making parallel building of many parts at once occur at the same speed as a single part of the same size.
Learning Objectives:
- Participants will be able to start considering complex geometries at the design stage of their ceramic components, unlocking performance enhancements that were not previously available to them.
- Participants will be able to design devices with selectable effective Dk in regions of any shape within the device.
- Participants will have an understanding of a sampling of 3D printed devices for demonstration purposes as a tool for a starting point in complex-shaped ceramic part design.
