Warpage Analysis of Electroplated Cu Films on Fiber-Reinforced Polymer Packaging Substrates

Polymers

Cheolgyu Kim²  Tae-Ik Lee²  Min Sung Kim¹  Taek-Soo Kim² 

[1] Samsung Electro-Mechanics, Sejong 339-702, Korea;Department of Mechanical Engineering, KAIST, Daejeon 305-701, Korea; E-Mails:

关键词: warpage;    fiber-reinforced polymer substrate;    built-in stress;    coefficient of thermal expansion (CTE) mismatch;   

DOI  :  10.3390/polym7060985

来源: mdpi

【 摘 要 】

This paper presents a warpage analysis method that predicts the warpage behavior of electroplated Cu films on glass fiber-reinforced polymer (GFRP) packaging substrates. The analysis method is performed using the following sequence: fabricate specimens for scanning 3D contours, transform 3D data into curvatures, compute the built-in stress of the film using a stress-curvature analytic model, and verify it through comparisons of the finite element method (FEM) simulations with the measured data. The curvature is used to describe the deflection and warpage modes and orientations of the specimen. Two primary factors that affect the warpage behavior of the electroplated Cu film on FRP substrate specimens are investigated. The first factor is the built-in stress in a Cu film that explains the room temperature warpage of the specimen under no thermal process. The second factor is the misfit of the coefficient of thermal expansion (CTE) between the Cu and FRP layer, which is a dominant factor during the temperature change. The calculated residual stress, and predicted curvatures using FEM simulation throughout the reflow process temperature range between 25 and 180 °C are proven to be accurate by the comparison of the FEM simulations and experiment measurements.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.