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Development and investigation of heat dissipation for thermal effect of Metal/Carbon composites

Title
Development and investigation of heat dissipation for thermal effect of Metal/Carbon composites
Author
Sangwoo Kim
Alternative Author(s)
김상우
Advisor(s)
윤준용
Issue Date
2019-02
Publisher
한양대학교
Degree
Doctor
Abstract
The major causes of electronic failure are four major factors cause contribute to the failure rate of electronic use, which are dust, vibration, humidity and temperature. It be caused by electronic failure comes from poor thermal management. According to study, shows the temperature on the reliability of the electronic devices must be in an allowable maximum temperature, ranging from 75 °C to 150 °C at all times during normal operation. Also junction life statistics show, failure rates rapidly increase when the junction temperature exceeds 150 degrees. Therefor it is necessary to have a reliable system that has the ability to improve the heat transfer and heat dissipated from chip component. Heat generation is significantly increased within the device, creating the need for a new heat spreader material to make heat dissipation more effective. Heat spreader materials that have high thermal dissipation and low thermal expansion similar to semiconductor PCB such as ceramics, silicon, and gallium arsenide that can prevent thermal shock. The light-emitting diode (LED) is a semiconductor light source emitting light operated at a specific wavelength. Note that when compared to fluorescent and incandescent lighting, LEDs feature fast response time, simple structure, environmental benign, vivid colors, high energy efficiency, longevity, and easier to put into mass production. Hence, LEDs are gradually replacing traditional light sources in every aspect of lighting applications because of their versatile benefits. However, in practice LED converts only 15–30% power input into light, leaving 70–85% energy into heat. In this regard, effective thermal management of the LED lighting is imperative to avoid failure of the LEDs. Thermal managements of LED lighting span three major categories: the package level, the board level, and the system level. Thermal management in package level or board level involves the selection of die structure, die bonding material, and substrate. In practice, the thermal resistance of the system level is very crucial. Carbon nanomaterials composites are become known as heat resistant components of high temperature industrial equipment due to their increased the utilization in applications such as high-electric properties, high-strength lightweight structural materials, and multi-function composite materials. In particular, it is receiving attention for its high-electric properties such as IT devices that are becoming compact and stubborn, LED heat insulation, and computer heat sink. There have been many attempts to improve the thermal properties of thermal dissipation materials. There are various alloys and composite materials to enhance thermal properties. The best way to improve properties by utilizing composite materials. There are many ways to use carbon nano-materials for metal matrix. Carbon nano-material is used to enhance properties of materials because it has excellent mechanical, thermal and electrical properties. Because graphene and CNT have excellent thermal properties(900W/m∙K ~ 6,000W/m∙K), they can be widely used to reinforcement properties of composite materials. However, carbon nanomaterials are difficult to use due to the resistance between of metal and carbon interfaces, condensation, and non-dispersion. In this thesis, carbon nanomaterial and metal particles were synthesized to solve metal and carbon surface problem with the method made metal and metal surface. The composite materials are prevented agglutination of carbon and carbon by the synthesis of metal particles in carbon nanomaterial, and combined metal/carbon nanocomposite materials to improve mechanical and thermal conductivity characteristics. The composite of Cu-RGO, Ag-CNT were used for composite metal/carbon materials used as reinforcement materials within metal bases, and network formed with Cu-RGO and Ag-CNT to create a heat path. Thermal conductivity was assessed by applying metal/carbon composite materials, and the highest thermal conductivity characteristics of 530W/mK were obtained with Ag-CNT as the character enhancing material on the silver base.
URI
http://dcollection.hanyang.ac.kr/common/orgView/000000108305https://repository.hanyang.ac.kr/handle/20.500.11754/100311
Appears in Collections:
GRADUATE SCHOOL[S](대학원) > MECHANICAL ENGINEERING(기계공학과) > Theses (Ph.D.)
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