2024

Vol.31 No.2

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  • Journal of the Microelectronics and Packaging Society
  • Volume 31(2); 2024
  • Article

Review

Journal of the Microelectronics and Packaging Society 2024;31(2):23-27. Published online: Jul, 25, 2024

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DOI : doi.org/10.6117/kmeps.2024.31.2.023

Time-Dependent Warpage Analysis for PCB Considering Viscoelastic Properties of Prepreg

  • Chanhee Yang1 , Chang-Yeon Gu1 , Min Sang Ju1 , Junmo Kim1 , Dong Min Jang2 , Jae Seok Jang2 , Jin Woo Jang2 , Jung Kyu Kim2 , and Taek-Soo Kim1,†
    1 Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291, Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea, 2 Samsung Electronics Co. Ltd., 1, Samsungjeonja-ro, Hwaseong-si, Gyeonggi-do 18448, Republic of Korea
Corresponding author E-mail: tskim1@kaist.ac.kr
Abstract

In this study, the time-dependent warpage behavior caused by the viscoelastic properties of prepreg in a printed circuit board (PCB) was analyzed by finite element method (FEM). The accurate viscoelastic properties of the prepreg were measured by stress relaxation test, which were then incorporated into constructed warpage analysis model. When the PCB was subjected to repeated thermal cycles, the warpage of the PCB was restored to its initial state when only the elastic properties of the prepreg were considered, but when the viscoelastic properties were also considered, the warpage was not restored and permanent warpage change occurred. The warpage analysis for three different types of prepreg was conducted to compare their mechanical reliability, and the results showed that materials with elastic properties dominating over viscoelastic properties experienced less warpage, resulting in better mechanical reliability.

Keywords Printed circuit board (PCB), Warpage, Prepreg, Finite element method (FEM), Viscoelastic property

REFERENCES
  • K. Kim, Y. Hwangbo and S.-H. Choa, “Warpage and Solder Joint Strength of Stacked PCB using an Interposer", J. Microelectron. Packag. Soc., 30(3), 40-50 (2023).
  • S. Cho, Y. T. Kim and Y. B. Ko, “A Study on Robust Design of PCB for Package on Package by Numerical Analysis with Unit and Substrate Level to Reduce Warpage”, J. Microelectron. Packag. Soc., 28(4), 31-39 (2021).
  • C. Kim, H. Choi, M. S. Kim and T.-S. Kim, “Packaging Substrate Bending Prediction due to Residual Stress”, J. Microelectron. Packag. Soc., 20(1), 21-26 (2013).
  • J. Kim, C.-Y. Gu and T.-S. Kim, “Thermal Warpage Behavior of Single-Side Polished Silicon Wafers”, J. Microelectron. Packag. Soc., 27(3), 89-93 (2020).
  • C. Kim, T. I. Lee, M. S. Kim and T. S. Kim, “Warpage Analysis of Electroplated Cu Films on Fiber-Reinforced Polymer Packaging Substrates”, Polymers, 7(6), 985 (2014).
  • P. Y. Lin and S. Lee, “Warpage Modeling of Ultra-Thin Packages Based on Chemical Shrinkage and Cure-Dependent Viscoelasticity of Molded Underfill”, IEEE Transactions on Device and Materials Reliability, 20(1), 67 (2019).
  • J. B. Pyo, T. I. Lee, C. Kim, M. S. Kim and T. S. Kim, “Prediction of Time-Dependent Swelling of Flexible Polymer Substrates Using Hygro-Mechanical Finite Element Simulations”, Soft matter, 12(18), 4135-4141 (2016).
  • T. I. Lee, C. Kim, J. B. Pyo, M. S. Kim and T. S. Kim, “Effect of Anisotropic Thermo-Elastic Properties of Woven-Fabric Laminates on Diagonal Warpage of Thin Package Substrates”, Composites Structures, 176, 973-981 (2017).
  • H.-S. Kim and H.-S. Kim, “Development of Warpage Simulation Method according to Thermal Stress based on Equivalent Anisotropic Viscoelastic Model”, J. Microelectron. Packag. Soc., 29(3), 43-48 (2022).
  • D. -H. Kim, S. -J. Joo, D. -O. Kwak and H. -S. Kim, “Anisotropic viscoelastic shell modeling technique of copper patterns/photoimageable solder resist composite for warpage simulation of multi-layer printed circuit boards”, Journal of Micromechanics and Microengineering, 25(10), 105016 (2015).
  • M. L. Williams, R. F. Landel and J. D. Ferry, “The Temperature Dependence of Relaxation Mechanisms in Amorphous Polymers and Other Glass-forming Liquids”, Journal of the American Chemical Society, 77(14), 3701-3707 (1955).
  • C. Kim, T.-I. Lee, M. S. Kim and T.-S. Kim, “Mechanism of warpage orientation rotation due to viscoelastic polymer substrates during thermal processing”, Microelectronics Reliability, 73, 136-145 (2017).