Samsung Electronics Co., Ltd.

Samsung Electro-mechanics Co., Ltd.

Samsung Led Co., Ltd.

Jin-Hak Choi

Nam-seog Kim

Kang-Wook Lee

Se-Young Jeong

Jong-Yun Kim

Bae-Kyun Kim

Seoung-Jae Lee

Eun-Ju Yang

Yeo-Joo Yoon

Disclosed are a method of electroless nickel-gold plating an object and a printed circuit board. The method in accordance with an embodiment of the present invention includes: forming a first nickel plated layer on a surface of the object; forming a second nickel plated layer on the first nickel plated layer; and forming a gold plated layer on the second nickel plated layer.

Method of nickel-gold plating and printed circuit board

A method of forming a solder bump may involve forming a first photoresist pattern on a wafer having a pad. The first photoresist pattern may have an opening that exposes a portion of the pad. A first under bump metallurgy (UBM) layer may be formed on the pad, and a second UBM layer may be formed on the first photoresist pattern. A second photoresist pattern may be formed that exposes the first UBM layer. A solder bump may be formed in the opening. The second photoresist pattern and the first photoresist pattern may be removed using a stripper, thereby removing the second UBM layer by a lift-off method.

Method of forming solder bump with reduced surface defects

A method of forming a solder bump may involve forming a first photoresist pattern on a wafer having a pad. The first photoresist pattern may have an opening that exposes a portion of the pad. A first under bump metallurgy (UBM) layer may be formed on the pad, and a second UBM layer may be formed on the first photoresist pattern. A second photoresist pattern may be formed that exposes the first UBM layer and covers the second UBM layer. A solder bump may be formed in the opening. The second photoresist pattern and the first photoresist pattern may be removed using a stripper, thereby removing the second UBM layer by a lift-off method.

Growing community of inventors

Suwon-si, South Korea

Jin-Hak Choi