A Simulation-Based Assessment of Print Accuracy for Microelectronic Parts Manufactured with DLP 3D Printing Process

Abstract

Due to its printing speed and high resolution, digital light processing (DLP) additive manufacturing technology has a steadily growing field of applications. Considering the possibility of DLP multi material printing, the creation of fully 3D printed complex conductive structures for microelectronic applications is a potential use case. However, to guarantee the geometric precision, a method to assess the printing process induced geometric deviations is required. In this study, the first parts of a modular simulation framework for describing the DLP 3D printing process were developed. The framework was designed to model the process-specific layer-by-layer curing and the resulting effects such as shrinkage due to crosslinking, residual stresses and curing-dependent mechanical properties. Cure depending elastic material properties were considered together with the chemical shrinkage to account for possible warpage. Additional modules were developed to account for effects like reaction-based heat generation, curing in cavities due to light penetration of printed layers as well as the release force during removal from the build platform. The framework was implemented in the Abaqus FEA software (Dassault Systèmes Simulia Corp, Providence, RI.). The capabilities of the framework were tested on four simple geometries including a PCB-like structure to show the potential for printed microelectronic parts. Results of the simulation showed the successful prediction of effects like warpage and print through error and were in good agreement with findings from the literature. The presented results showed the potential of the framework to predict the DLP process inherent manufacturing imprecision and is thus a good basis for the further development of multi material printing of electronic structures.