The Influence of Gold Wire Quantity on the Encapsulation of Light-Emitting Diodes

Abstract

In the realm of high-power LED applications, several critical concerns emerge, significantly impacting LED operational efficiency and reliability. Among these concerns, wire deformation during the LED encapsulation process poses a substantial threat to LED longevity. This research endeavors to investigate the influence of gold wire quantity on the LED encapsulation procedure. Leveraging ANSYS Fluent, our study employs the Volume of Fluid (VOF) technique along with a user-defined function (UDF) to model the deposition of epoxy materials onto the LED. Moreover, ANSYS Fluent is harnessed for a comprehensive analysis of fluid-structure interaction (FSI) phenomena that occur between the gold wire bonding and the epoxy materials. The FSI modeling allows us to indirectly quantify the stress exerted on the gold wire bonding during the encapsulation process. Our simulations encompass a range of gold wire quantities, spanning from 1 to 5, while a validation experiment is conducted to affirm the structural integrity of epoxy materials as per the simulation setup. Our findings reveal a direct correlation between increased epoxy material density and heightened wire deformation, stress levels, and strain distribution on the wire bonding. For EMC, which has the highest density, the maximum gold wire deformation, Von Mises stress, and strain distribution on the gold wire are 2.6616×10–8 mm, 0.00064 MPa, and 8.2019×10–9, respectively. Additionally, the simulations underscore that augmenting the number of gold wires exacerbates stress and strain distribution, assuming consistent epoxy material usage. The present study will contribute to the understanding of the mechanical aspects linked with LED encapsulation and present potential opportunities for improving manufacturing procedures and guiding future experimental attempts in this research domain.

Keywords

• computational methods
• encapsulation process
• led