Haixia Yang

Preparation and Properties of Glass Cloth-reinforced Meltable Thermoplastic Polyimide Composites for Microelectronic Packaging Substrates

Meltable thermoplastic polyimide resins (MTPI) with designed polymer backbones and controlled molecular weights for advanced microelectronic packaging substrate application have been synthesized by thermal polycondensation of aromatic dianhydride and aromatic diamine in presence of endcapping agent. The thermoplastic polyimide resins could be dissolved in organic solvents to give low viscosity solutions, which were then employed to impregnate E-glass cloth (EG) to yield MTPI/EG prepregs. After removal of the organic volatile, the MTPI/EG prepregs were plied up and then melt processed to give MTPI/EG composite laminates with high quality. Experimental results demonstrated that the MTPI/EG composite laminates showed desirable characteristics, including: (1) excellent thermal stability (2) good mechanical properties (3) great electrical insulating and dielectric properties as well as (4) high peel strength between copper foil and the composite surface.Meltable thermoplastic polyimide resins (MTPI) with designed polymer backbones and controlled molecular weights for advanced microelectronic packaging substrate application have been synthesized by thermal polycondensation of aromatic dianhydride and aromatic diamine in presence of endcapping agent. The thermoplastic polyimide resins could be dissolved in organic solvents to give low viscosity solutions, which were then employed to impregnate E-glass cloth (EG) to yield MTPI/EG prepregs. After removal of the organic volatile, the MTPI/EG prepregs were plied up and then melt processed to give MTPI/EG composite laminates with high quality. Experimental results demonstrated that the MTPI/EG composite laminates showed desirable characteristics, including: (1) excellent thermal stability; (2) good mechanical properties; (3) great electrical insulating and dielectric properties; as well as (4) high peel strength between copper foil and the composite surface.

Multi-Methyl-Substituted Polyphenylquinoxalines with High Solubility and High Glass Transition Temperatures: Synthesis and Characterization

New polyphenylquinoxalines (PPQs) containing methyl substituents have been synthesized and characterized. The PPQs were prepared by the polycondensation of a newly-developed aromatic tetraketone, 4,4′ -bis(4-benzilyloxy)-3,3′,5,5′ -tetramethylbiphenyl (III) and aromatic tetraamines. Compared with the non-methyl-substituted PPQs derived from 1,4-bis (4-benzilyloxy)benzene (I) and 4,4′ -bis(4-benzilyloxy)biphenyl (II), the obtained polymers exhibited better solubility. They were soluble not only in the common m-cresol and chloroform, but in polar aprotic solvent N-methyl-2-pyrrolidinone (NMP). The polymers showed glass transition temperatures of 325°C for PPQ-IIIa (from III and 3,3′,4,4′ -tetraaminobiphenyl) and 287°C for PPQ-IIIb (from III and 3,3′,4,4′ -tetraaminodiphenyl ether), which were much higher than their analogues. The PPQs exhibited good thermal stability up to 470°C in nitrogen and good optical transparency at 450 nm with a thickness of around 10 μ m. The refractive indices and birefringences of the PPQs were in the range of 1.6998–1.7739 and 0.0002–0.0007, respectively.

Synthesis and Characterization of Fluorinated Bisphenols and Tetraphenols via a Simple One-Pot Reaction

Abstract Fluorinated bisphenols and tetraphenols have been prepared by the condensation reaction of trifluoromethyl activated ketones with simple bisphenols (including catechol, resorcinol, and hydroquinone) catalyzed by trifluoromethanesulfonic acid, in good yields. Supplemental materials are available for this article. Go to the publishers online edition of Synthetic Communications® to view the free supplemental file. GRAPHICAL ABSTRACT

Controlling the morphology and orientation of Cu 6 Sn 5 through designing the orientations of Cu single crystals

It is found that the morphologies and orientations of Cu<inf>6</inf>Sn<inf>5</inf> can be well controlled through designing orientations of Cu single crystal substrates. On (001) and (111) Cu single crystals, Cu<inf>6</inf>Sn<inf>5</inf> grains display regular prism-type morphology and align either along two perpendicular directions or along three directions having an angle of 60° between each other. By electron backscatter diffraction (EBSD) method, the preferred orientations of the Cu<inf>6</inf>Sn<inf>5</inf> grains are determined to strongly depend on the orientations of the Cu single crystals.

Synthesis and Characterization of Novel Multiaromatic Epoxy Resin for Advanced Microelectronic Packaging Applications

The novel multiaromatic epoxy resin and hardener was synthesized and characterized. The mechanical, thermal, electrical as well as flame retardant properties of cured epoxy resins were systematically investigated. Experiment results indicated that the cured novel multiaromatic resins exhibited very good mechanical properties, good electrical properties, high glass transition temperature, good dielectric properties, low moisture absorption and very good flame retardancy.

Aromatic Polyimide Resins for High Density Packaging Substrates

Molecular weight-controlled aromatic polyimide resins for fabrication of high density IC packaging substrates have been developed. The aromatic polyimide resins showed good laminate processability, which could easily dissolve in organic solvent to give low viscosity solution for impregnation of E-glass fiber cloths. After completely removal of the organic volatile, the polyimide/glass fiber (PI/GF) cloth prepreg could be plied up and then thermally cured at 280degC to give the PI/GF laminate suitable as packaging substrate core. Experimental results indicated that the polyimide laminates have the desirable characteristics for packaging substrate core, including 1) excellent thermal stability with initial thermal decomposition temperature of >500degC, CLE(in-plane) of 15-19 ppm/degC and glass transition temperature of >220degC; 2) good mechanical properties with flexural strength of >430 Ma and flexural modulus of 20 GPa, tensile strength of >230 MPa and impact toughness of 84 kJ/m2; 3) great electrical insulating and dielectric properties with volume resistivity of >1016 Omegaldrcm, dielectric constant of 4.1 and dissipation factor of 0.005 etc.; and 4) high peel strength of copper foil to laminate in Cu-claded laminate (>1.5N/mm).