Simulation methodology development of warpage estimation for epoxy molding compound under considerations of stress relaxation characteristics and curing conditions applied in semiconductor packaging

Exploring the Influence of Material Properties of Epoxy Molding Compound on Wafer Warpage in Fan-Out Wafer-Level Packaging

“…Figure 2 shows a schematic diagram of the structure during the decarrier process, where "Die" represents the chip, "Si THK" represents the stop layer (silicon nitride-a high dielectric constant material), "Passivation" represents the passivation layer, "Cu-pillar" represents the copper pillar, and "epoxy molding compound (EMC)" represents the epoxy molding compound. Many previous studies [1][2][3][4][5][6][7][8][9][10][11][12][13][14] have focused on evaluating whether changes in the structural design or material selection of the packaging can reduce the amount of wafer warpage caused by the thermal process in fan-out wafer-level packaging (FOWLP). Analyzing the effect of material properties on wafer warpage is one of the important ways of understanding warpage factors and effectively improving wafer warpage.…”

“…Marius et al [11] analyzed the warpage of two different EMCs during the first thermal cycle in FOWLP and found that different material properties of EMC not only result in different warpages but also cause variations in wafer deformation. Lee et al [12] found, after analyzing the curing shrinkage of EMC, that the main factor affecting warpage during the curing process is CTE, due to the mismatch between the CTE of EMC and other structural layers, leading to differences in thermal shrinkage and warpage. Wang et al [13] researched the effect of the chemical shrinkage of EMC on the stress generated in other structures during compression molding.…”

“…In previous studies [1][2][3][4][5][6][7][8][9][10][11][12][13][14], analysis of the effect of material properties on warpage was mostly focused on the differences in the types of materials or the magnitude of the coefficient of thermal expansion (CTE). However, there are currently few comprehensive discussions on the various material property parameters of the EMC materials, such as Young's modulus of the EMC before the Tg between 25 • C and 35 • C (E L ) and after the Tg between 235 • C and 260 • C (E H ), the thermal expansion coefficient (α1, α2), and the temperature interval (∆T) between E L and E H .…”

“…However, there are currently few comprehensive discussions on the various material property parameters of the EMC materials, such as Young's modulus of the EMC before the Tg between 25 • C and 35 • C (E L ) and after the Tg between 235 • C and 260 • C (E H ), the thermal expansion coefficient (α1, α2), and the temperature interval (∆T) between E L and E H . Table 1 compares the quantification of wafer warpage with respect to EMC parameter characteristics in previous studies [1][2][3][4][5][6][7][8][9][10][11][12][13][14] and this study, as well as the optimization of EMC design characteristics. It is essential to identify the critical influencing factors and quantify the effects of each parameter on the warpage of the structure.…”

Validation of New Substrate Design for the Improvement of Strip Warpage on LGA Packages

“…From enormous size of integrated circuits or ICs to nano size processors that can be found on advanced gadgets we use every single day of our lives. Every individual is committed to achieve satisfaction and quality of their products and services [1][2][3][4].…”