Influence of Material Properties on the Fluid-Structure Interaction aspects during Molded Underfill Process

C.Y Khor,Muhammad Ikman Ishak,M.S Abdul Aziz,Mohd Riduan Jamalludin,M.U Rosli,M.S Zakaria,A.F.M Yamin,M.Z Abdullah,M.A.B Abdullah,S.Z Abd Rahim,M.F Ghazali,M.E Muhammad Suandi,M.N Mat Saad

doi:10.1051/matecconf/20179701059

Abstract

This paper presents the investigation of the effects of epoxy moulding compound’ (EMC) viscosity on the FSI aspects during moulded underfill process (MUF). Finite volume (FV) code and finite element (FE) code were connected online through the Mesh-based Parallel Code Coupling Interface (MpCCI) method for fluid and structural analysis. The EMC flow behaviour was modelled by Castro-Macosko model, which was written in C language and incorporated into the FV analysis. Real-time predictions on the flow front, chip deformation and stress concentration were solved by FV- and FE-solver. Increase in EMC viscosity raises the deformation and stress imposed on IC and solder bump, which may induce unintended features on the IC structure. The current simulation is expected to provide the better understandings and clear visualization of FSI in the moulded underfill process.

Highlights

Transfer moulding is a well-known technique used for the integrated circuit (IC) encapsulation
The FSI simulation using Mesh-based Parallel Code Coupling Interface (MpCCI) coupling method was considered in the study on an IC package with dimensions of 9 mm × 9 mm × 0.7 mm, which consisting of a silicon chip (5 mm × 5 mm × 0.25 mm) and perimeter arrangement of solder bumps
The investigation of the effects of material properties by considering the FSI aspects in moulded underfill (MUF) process has been carried out using finite volume and finite element codes, which coupled by MpCCI software

Summary

Introduction

Transfer moulding is a well-known technique used for the integrated circuit (IC) encapsulation. The interaction between EMC and IC structures (i.e., silicon chip, solder bump, wire bonding, paddle and leadframe) may induce unintended defects; reduces packaging reliability. The investigations of the moulded underfill process for an IC package considering FSI aspect with MpCCI coupling method [1,2,3] are still lacking. The FSI simulation using MpCCI coupling method was considered in the study on an IC package with dimensions of 9 mm × 9 mm × 0.7 mm, which consisting of a silicon chip (5 mm × 5 mm × 0.25 mm) and perimeter arrangement of solder bumps. The EMC flow front profile, chip and solder bump stress were investigated through the FSI simulation. Three types of EMC [6,7,8] (e.g., Sumikon EME 6300HN, SUMITOMO 6300 HG) with different material properties, namely Case 1, 2 and 3 were considered in the analysis

Viscosity models

Deformation of silicon chip

Conclusion