3D photocuring for circuit fabrication: optimization of UV penetration properties via the morphology of silver particles

Photocuring printing technology is extensively applied in the manufacturing complex structure for electrical components owing to its excellent printing flexibility and efficiency. However, the limited penetration depth of UV photocured silver pastes (UVSPs), resulting from the complex interaction between incident light and conductive fillers, restricts circuit fabrication. In this work, we optimized the selection of flaky silver particles as UVSP fillers instead of the conventional spherical ones by simulating the penetration distribution of incident light in UVSPs with various morphologies through the finite element method. The fluidity, polymerization behavior, and printing properties of the UVSPs were investigated. As a result, flaky particles filled UVSP with the unique light penetration properties can be used for high-precision film printing, and the printing linewidth accuracy can be improved by over 20 μm under the same exposure conditions. Furthermore, the conductive film with flaky particles effectively prevented curling and peeling during low-solid-content sintering and exhibits a good electrical conductivity of 1.26×10 6   S/m. This study provides valuable technical guidance for the rapid preparation of low-cost, high-precision circuit printing using photocuring printing technology, which significantly reducing the manufacturing cost of printed electronic components.