Samsung Electronics Co., Ltd.

Chang-Woo Ko

Jae-Hoon Jeong

Ki-jae Song

Hun-Kyo Seo

Sang-Hoon Lee

Young-Ho Lee

Young-Soo An

Jea-Eun Lee

Se-jang Oh

Myung-Hee Sung

A memory module includes a plurality of buses. A plurality of memory chips is mounted on a module board and is connected to a first node, a second node, and a plurality of third nodes of the plurality of buses. The first node, the second node, and the third nodes branch off to a first memory chip, a second memory chip, and the third memory chips, respectively. A length of the plurality of buses between the first and second nodes is longer than a length of the plurality of buses between adjacent nodes from among the second node and the third nodes.

Memory module for high-speed operations

In a method of designing a printed circuit board, a package capacitance, a package inductance, and a chip capacitance of an actual memory device are calculated. A signal line capacitance and a signal line inductance per unit length of a signal line are calculated based on characteristics of the printed circuit board. A length of the signal line for each pin is determined based on the package capacitance and the signal line capacitance.

Package test devices having a printed circuit board

Method of designing a printed circuit board

A wafer test equipment system includes a performance board connected to a tester head of a tester. A universal block printed circuit board is positioned on the performance board, directly connecting a plurality of normal signal lines to a probe card and dividing each of a plurality of power signal lines into multiple paths and connecting them to the probe card. A cable assembly transfers the normal signal lines and the power signal lines between the universal block printed circuit board and the tester head. The cable assembly is soldered directly to the universal block printed circuit board in a perpendicular direction through a center portion of the performance board. A probe card is removably secured to the performance board including the universal block printed circuit board. The probe card includes an interposer on an upper surface thereof, a ceramic multi-layer substrate positioned below the interposer, and a plurality of needles positioned below the ceramic multi-layer substrate on a lower surface thereof opposite the upper surface.

Interface structure of wafer test equipment

Growing community of inventors

Seoul, South Korea

Chang-Woo Ko