英文文献.docx

1、英文 文献南湖学院毕业设计（论文）外文翻译资料作 者彭泽诚届 别2013届系 别机械与电子工程系专 业机械设计制造及其自动化指导老师刘伟香职 称副教授完成时间2013年5月10日原文：Recent Advance in Cooling Technique s for CPUAbstract:With the improvement son of the chip integration density,providing effective heat removal solutions for CPU is an essential research project in t he elect

2、ronics industry. Taking aim at t he problem caused by heat generation of CPU , this paper mainly discussed t he current development s , principles of heat t rans2 fer and per spective applications of t he three novel microcooling met hods , including heat pipe , micro channel and cool chip . Advanta

3、ges and shortcomings of t hose methods and t he relative critical issues were evalua2 ted. Prospect in t he chip cooling area was al so stated.Key words:chip cooling technique ; heat pipe ; micro channel ; cool chipElectronic cooling concerns the reliability and service life of electronic devices, i

4、s today a bottleneck in the development of electronic industry.Along with high performance, miniaturization and integration of electronic industry development trends of, the thermal problem has become increasingly prominent. Especially in terms of sensitivity high CPU heat load, heat is accumulated

5、at the chips would seriously affect its stability and service life.Studies have shown that elevated operating temperature 10for a single electronic components, their reliability is reduced 50%;55% CPU failure is caused by overheating.At present, the high frequency of Pentium4 3. 2 e had exceeded 100

6、 w power consumption of mark Smith2field core Pentium d dual-core processors power consumption is climbing to 130 w.According to Intels Chief Technology Officer Pat Rick Gel singer Projections, if the number of transistors in a chip at the present rate of growth, until 2015, and as hot as the surfac

7、e of the Sun 1, which of course is unthinkable.Therefore, in order to enable the CPU to maximize performance and ensure its reliability, research on practical and efficient chip cooling methods are becoming increasingly important and urgent issues.This article is to review the recent advances in CPU

8、 heat sink technology. 1、 CPU cooling and existing problemsAccording to the theory of electronics, overheating as a result of the electronic transfer 2 is a damaged CPU chips inside the main reason. Electronic transfer refers to the electronic flow of metal atoms as a result of the migration phenome

9、non.Chip on the current very high levels of metal wire, a momentum of electrons flowing to the metal atom, once with a metal atom collisions, makes the move metal atoms from the metal surface, results lead to formation on metal surface pit, or mound.This is a permanent and irreversible harm if this

10、chronic process continue, in the end it will cause the core internal circuit for short circuit or open circuit completely damage the CPU. Electronic migration because of the many factors and temperature factors played a decisive role.Higher temperatures will make free-electron kinetic energy has gre

11、atly increased, the metal atom collisions are more strongly.At the same time, with increasing temperature, thermal motion of atoms of metal has increased, electronic transfer, the more prone.This is why CPU temperature is maintained at 50 c the following reasons. Air cooling method.Installing the he

12、at sink on the CPU to increase the cooling area, and installed a small fan on the heatsink, air forced convection and take the heat.Advantage of this cooling method is simple, practical, and inexpensive.But the disadvantage: cooling efficiency is low, can only drain CPU waste heat of up to 60%, ther

13、efore only rely on law of conduction and convection air cooling heat sink thermal conductivity is close to its limit; as the power and speed of the fan increases, also increases the noise; fan is moving parts more easily damaged.Water cooling method.It is sealing good sink (usually made of aluminium

14、 or aluminium alloys) sticker on top of CPU surface, and then passes to the water circulation system, issued by the CPU heat away.Higher thermal efficiency than the cooling of this approach, but it requires more complex water cooling system and inconvenience, installation problems, and theres been l

15、eakage and condensation problems.Semiconductor cooling method.It is based on the PAL sticker effect 3 achieved, often semiconductor ceramic package series.It works in practice is a thermal transfer, when turn on the DC current, cold temperatures rapidly decrease in semiconductor, even down to-10 c,

16、and a rapid increase in temperature on the other side, so as to reduce the surface temperature.Advantages of semiconductor cooling is no refrigerant, long life, easy to install and can be controlled through current for high-precision temperature control.It also exists disadvantages: refrigeration ef

17、ficiency is low; technology not mature .High prices; easy CPU condensation due to cold temperature is too low, resulting in a short circuit.Therefore, with the increase of constantly decreasing chip size, CPU frequency and the rapid increase in heat, need a new CPU heatsink to replace existing cooli

18、ng technology. Following introduces 3 new CPU heat sink technology: heat-pipe cooling technology, technology of micro-channel heat sinks and cooling chip technology.2、 New CPU cooling technology2.1 Heat pipe technology Heat pipe is based on phase-change heat transfer enhancement technology, it close

19、d in vacuum tube material, repeated boiling and condensation to transfer heat.Typical heat pipe followed by evaporation, thermal insulation and condensation can be divided into three parts (see Figure 14).Mount liquid known as working fluid in a pipe, is the heat transfer medium.First, the evaporati

20、on of boiling working fluid absorbs heat from the outside air, and under the driving force of the air pressure difference access to condensed, encounters cooler pipe wall will condense to liquid and heat;Then, by setting the wick tube at the Center, which with the work generated by the surface tensi

21、on of the liquid suction liquid back to the evaporator again.Repeated the above process, so as to keep the evaporator heat transfer to the condensing section 6, and then delivered through the heat sink.As the tube is passed through the latent heat of phase transformation heat, its thermal conductivi

22、ty is high, or even dozens of times more than double of the same size copper pipe, therefore suitable for emission of high heat in a small space, has been applied in the laptop.Cot ter first proposed the concept of micro heat pipe.The text embedded on the chip of micro heat pipes, average pipeline 1

23、0500 m in diameter, mm to several cm long.This tube does not need to capillaries structures, polygonal shape of cross section through the cavity angle as the liquid refrigerant return channel, as well as through Tsim District axial capillary pressure difference of the liquid refrigerant from the con

24、densing pressure back to the evaporator, so as to complete the refrigerant cycle.Because of micro heat pipe combines advantages of MicroChannel cooling and enhanced heat in a small space was very promising.There have been reports, using IC cables made of micro heat pipe array, the cooling power of u

25、p to 200 W/cmInvented by Maidanik is another form of loop heat pipe heat pipe.As it can in the case of small temperature difference, long distance delivery a lot of heat, so in terms of aerospace broader application, also in the application of computers and electronic devices have a very broad prosp

26、ects.Since the experiment for the first time since 2001, many have come around 50 g l HP heatsink, heatsink of heat flux in 2530 w.People also tested a new type of 6 mm in diameter HP heat sink, its maximum thermal flux is about 70 w.But since l HP mainly developed nearly 20 years new technology, th

27、eoretical and applied aspects require further in-depth study.To sum up, it tube has the advantage of its excellent thermal conductivity and isothermal and thermal response speed, light weight and simple structure.Moreover, as heat pipes have no moving parts, reliable, durable, and can work in weight

28、lessness, heat and long distance and without direction restriction. Of course, traditional heat pipe design is also present on the capillary, flying, boiling, Sonic and adhesive on the limit, when the size and variable hours, and phase change of surface tension on considering the small size effect,

29、as well as using polygon channel structure designed to replace the current common triangle runner, is the important subject of analysis on heat pipe design.2.2 Micro-Channel cooling technologyMicroChannel heat sink concept first by Tuckerman and the Peace in 1981 proposed 10, 11, which is made up of

30、 materials with high thermal conductivity.According to Riddle, 12 research: when the flow must be rectangular channel mid channel and overall heat-transfer coefficient of water is inversely proportional to the diameter 12.As the channel diameter decreases, increased heat transfer coefficients, while

31、 cooling area and volume than the system has significantly increased.So although the volume continuously decreases, greatly improving heat dissipation.From Figure 3 in the can see, two species has same length and height of micro-channel set hot Manager, dang micro-pipeline width for 10 m Shi, CPU te

32、mperature for 65 , and Dang width for 100 m Shi, CPU temperature is up to 85 , apparently width more small on thermal more enabling, therefore, size factors on micro-channel thermal Manager of effect is critical of, and this and directly effect has CPU of run performance.In the area of micro-channel heat sinks, more mature should be United States Cooligy introduced its product.Its water-cooled chips production, using the active micro-channel cooling technology (Active Micro2ChannelCooling, AMCC).This new technology consists of 3 main parts: micro pi