Abstract: A flip-chip packaging process is disclosed. The present invention is featured in forming a copper pillar on a wafer, forming a solder on a substrate; and enabling the solder to substantially cover the entire externally-exposed surface of the copper pillar, thereby connecting the copper pillar to the substrate. The copper pillar of the present invention can be such as a prism or a cylinder.

Abstract: A method for forming metal bumps is provided. A bonding pad is first formed on the active surface of a chip and then a passivation layer is formed on the active surface of the chip and exposes the bonding pad. An under bump metallurgy is formed on the active surface of the chip to overlay the bonding pad. A layer of patterned photoresist is formed on the under bump metallurgy and exposes the portion of the under bump metallurgy on the bonding pad. A layer of copper is plated on the exposed portion of the under bump metallurgy and then a layer of solder is printed on the copper layer. Afterward the solder is reflowed to form a spherical metal bump. Finally, the photoresist layer is removed and the exposed portion of the under bump metallurgy is etched out.

Abstract: A flip-chip packaging process is disclosed. The present invention is featured in forming a copper pillar on a wafer, forming a solder on a substrate; and enabling the solder to substantially cover the entire externally-exposed surface of the copper pillar, thereby connecting the copper pillar to the substrate. The copper pillar of the present invention can be such as a prism or a cylinder.

Abstract: Disclosed herein are second order nonlinear optic polyimide polymers comprising repeating units represented by the formula: wherein each of the substituents is given the definition as set forth in the Specification and Claims. Also disclosed are the preparation processes of these polymers, chromophore-forming compounds for synthesis of these polymers, and the intermediate polymers thereof. The second order nonlinear optic polyimide polymers of formula (I) may be used in the manufacture of electro-optic (EO) devices, such as electro-optic waveguide devices.

Abstract: Disclosed herein are second order nonlinear optic polyimide polymers comprising repeating units represented by the formula: wherein each of the substituents is given the definition as set forth in the Specification and Claims. Also disclosed are the preparation processes of these polymers, chromophore-forming compounds for synthesis of these polymers, and the intermediate polymers thereof. The second order nonlinear optic polyimide polymers of formula (I) may be used in the manufacture of electro-optic (EO) devices, such as electro-optic waveguide devices.