• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.02a
• /
• pp.323-323
• /
• 2013

High power light-emitting diodes (LEDs) are widely used in many device applications due to its ability to operate at high power and produce high luminance. However, releasing the heat accumulated in the device during operating time is a serious problem that needs to be resolved to ensure high optical efficiency. Ceramic or Aluminium base metal printed circuit boards are generally used as integral parts of communication and power devices due to its outstanding thermal dissipation capabilities as heat sink or heat spreader. We investigated the characterisation of electroless plating of Ni-B film according to plating bath temperature, ranging from $50^{\circ}C$ to $75^{\circ}C$ on Ag paste/anodised Al ($Al_2O_3$)/Al substrate to be used in metal PCB for high power LED packing systems. X-ray diffraction (XRD), Field-Emission Scanning Electron Microscopy (FE-SEM) and X-ray Photoelectron Spectroscopy (XPS) were used in the film analysis. By XRD result, the structure of the as deposited Ni-B film was amorphous irrespective of bath temperature. The activation energy of electroless Ni-B plating was 59.78 kJ/mol at the temperature region of $50{\sim}75^{\circ}C$. In addition, the Ni-B film grew selectively on the patterned Ag paste surface.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2016.11a
• /
• pp.165.1-165.1
• /
• 2016

표면활성화 접합은 이종 소재의 표면을 제어하여 직접 접합하는 기술이다. 본 연구에서는 표면활성화 접합을 이용하여 고 방열특성의 LED용 히트스프레더(heat spreader)를 제작하기 위하여 $Al-Al_2O_3$ 복합소재를 제조하였다. LED 제품의 히트스프레더는 LED에서 발생하는 열을 한 곳으로 집중하는 것을 막아 열을 분산하는 금속판을 의미한다. 최근의 LED 제품은 고출력화에 의한 발열량의 급증으로 MCL(Metal Clad Laminate)를 이용하여 LED 칩에서 발생된 열을 외부로 배출하는 모듈구조를 나타내는 경우가 대다수이다. LED에서 열이 증가하게 되면 LED의 효율이 감소하고, 수명이 줄어드는 현상을 보이기 때문에 방열특성은 매우 중요하다. 따라서 고출력화되어 LED 칩에서 발생되는 열을 제어하는 기술이 이슈화 되고 있다. 기존의 히트스프레더 구조는 통상적으로 Al/절연층(폴리머)/Al으로 폴리머의 열전도율이 1W/mk로 고출력화에 의해 급증하는 LED의 발열량을 충분히 해소시키기 어렵다. 본 연구에서는 급증하는 LED의 방열량을 해소시키기 위해서 기존의 Al/폴리머/Al의 구조를 $Al/Al_2O_3/Al$의 구조로 개발하기 위해서 HV-SCDB 기술을 이용한 $Al-Al_2O_3$ 복합소재 제조 및 접합특성에 관하여 연구하였다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2008.10a
• /
• pp.1529-1531
• /
• 2008

Since the discovery over a decade ago, carbon nanotubes (CNTs) have been attracting considerable attentions both from scientists and engineers. Because of the excellent field emission properties, such as high aspect ratio, extremely small diameter, and high emission current, CNTs become a potential candidate as field emitter for field emission display (FED) and lighting (FEL) as backlight for LCD. Due to the exceptional physical properties, such as superior thermal and electrical conductivities, as well as high stiffness and strength, the CNT-based composites can be as light-weight heat-sink or thermal spreader materials used for power electronic devices, such as power LED for general illumination. The CNTs for above applications will be reviewed, and related materials and devices will be demonstrated in this paper.

• Journal of the Korea Society of Computer and Information
• /
• v.14 no.1
• /
• pp.145-151
• /
• 2009

There are excessively hot units of a microprocessor in today's nano-scale process technology, which are called hotspots. Hotspots' heat dissipation is not perfectly conquered by mechanical cooling techniques such as heatsink, heat spreader, and fans; Hence, an architecture-level temperature simulation of microprocessors is evident experiment so that designers can make reliable chips in high temperature environments. However, conventional thermal simulators cannot be used in temperature evaluation of real machine, since they are too slow, or too coarse-grained to estimate overall system models. This paper proposes methodology of monitoring accurate runtime temperature with Hotspot[4], and introduces its implementation. With this tool, it is available to track runtime thermal behavior of a microprocessor at architecture-level. Therefore, Dynamic Thermal Management such as Dynamic Voltage and Frequency Scaling technique can be verified in the real system.