The Effects of Amide Groups on the Thermal and Optical Properties of Poly(amide‐imide)s with Low Residual Stress for Microelectronic Devices

Abstract

In this study, poly(amide-imide)s are synthesized for electronic materials by adding amide groups into polyimide. As it is expected, poly(amide-imide) shows an amorphous structure with a lower glass transition temperature and residual stress than the neat polyimide due to the high steric hindrance of the amide group. Also, the modifi cation to the polyimide structure leads to higher transmittance and enhances colorless properties. Consequently, successful synthesis of poly(amide-imide) s is demonstrated which has wide applicability in the electronic industries due to their low glass transition temperature. It is expected that semiconductor and integrated circuit products can be manufactured utilizing poly(amide-imide)s with high reliability and a low chance of cracking due to their lower residual stress. Furthermore, it envisioned that the improved optical properties of poly(amide-imide) materials will allow for their applications in transparent displays and coating products.

Adhesion and Interface Studies of the Structure‐Controlled Polyimide with Smooth Copper for High‐Frequency Communication

“…Apart from CTE mismatch, the high residual stress after curing is also one of the important reasons to destroy the adhesion of PI and Cu. [ 22b ] On the whole, residual stress is composed of intrinsic stress and thermal stress. [ 31 ] PI after spin‐coating and curing on the surface of the substrate would generate large intrinsic stress at the interface resulted from the volume shrinkage and the limitation of the movement of the molecular chain caused by the evaporation of the solvent during the thermal imidization.…”

“…[ 31 ] PI after spin‐coating and curing on the surface of the substrate would generate large intrinsic stress at the interface resulted from the volume shrinkage and the limitation of the movement of the molecular chain caused by the evaporation of the solvent during the thermal imidization. [ 22b,c ] Moreover, the original molecular structure and inherent physical properties of PIs are also important for intrinsic stress. On the other hand, thermal stress (σ f ) according to the following function …”

“…[ 21 ] Moreover, there is always high residual stress after the curing process of PI, leading to the warpage of the thin wafer resulting in the peeling of PI/Cu interface and failure of the whole electronic device. [ 4a,22 ] So, a novel PI material with high interface adhesion strength to smooth Cu, as well as suitable CTE and low residual stress should be carefully proposed and synthesized for the high‐frequency transmission application in FOWLP.…”

Colorless poly(amide‐imide) copolymers for flexible display applications

“…Thus, moieties which can prompt inter-and intra-molecular interactions, such as amide, pyridine, pyrimidine, benzimidazole, have been introduced into CPIs to improve their mechanical properties and dimensional stability. [29][30][31] For instance, Hasegawa et al developed a series of CPIs through the combination of CBDA, 6FDA, TFMB, and novel ester or amide-containing monomers. Some of these CPIs with amide moieties exhibited good solubility in organic solvents, low CTE (<15 ppm K À1 ), excellent optical transparency, and high tensile strength (up to 278 MPa), modulus (>6 GPa), and elongation-at-break (>10%).…”

Residual stress and thermal properties of rubber‐modified epoxy systems for semiconductor package

“…Han et al 20,21 studied the relationship between residual stress and adhesion strength of polyimide films with different chemical backbone structures. The results showed that 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride (BTDA) ‐ 4,4′‐diaminodiphenyl ether (ODA) polyimide exhibited low residual stress and good adhesion to copper.…”