| With computer widely applied in the field of scientific research andengineering, the demand of computer about operation rate and date-processing isgrowing up, which causes the integration of computer chip much higher thanbefore.In the near future the chip's operating frequency will up to 4GHz or higher,thus the heat power of chip will be more than 100W with it's size maintain nearlyinvariable. which makes its temperature grow up significantly. Therefore, the heatradiation become the important key to solve the chip's security and reliability. Thearticle analyzed the research situation of chip's heat radiation in both domestic andforeign countries, presents each method's working principle of heat radiation. Thewater-cooling technology and water-cooling system driven by piezoelectric(PZT)pump were detailed introduced and studied. according to the development tendencyof chip radiator.The article introduced various heat transfer types and it's working principle inheat radiation system according to the heat conduction theory. It was concludedthat the heat radiation system generally include heat sink, radiator, heat radiationfan, piezoelectric pump etc. In the article the influence of each part on the effect ofheat radiation were analyzed. From the analysis, it was put forward that the heatradiation system should satisfy the requirement of heat absorption, heat conductionand heat radiation and pointed out the main influence factor to these designingrequirements.In order to design excellent performed heat sink and heat radiator so as toexchange heat to the environment as soon as possible, Theories of inner-pipedlaminar flow friction loss, forced convective heat conduction, heat transmissionthrough ribs of radiator and flow's sweeping lengthways wide plane are used todesign heat sinks and radiators. What's more, measures to improve heattransmission were introduced. The definite factor for radiator size which with theheat radiation rib were analyzed and the the impact of each part's size on the effectof heat radiation and it's coupling relation were also analyzed. According to abovetheories, different types of heat sink and radiator were constructed, and theprototype of water-cooling system were built in two different forms.Heat in the water-cooling system transmitted via cooling medium whichdriven by PZT pump, so the quality of PZT pump has a prominent influence on theperformance of heat radiation. PZT pump changes its chamber volume by counterPZT effect of the PZT's diaphragm, and with the help of single-directioned valve,fluid can be pumped toward one direction. The working principle and vibrationequation of PZT's diaphragm are explained. Through experiment, the proper drivesignal for PZT's diaphragm was found, and the characteristic of vibration, therelationship among it's deformation and frequency,voltage were also studied. Thearticle made the samples of PZT pump with double chambers both inparallel-connectioned and in series connectioned on the basis of single chamberpump, and describes its structure and working principle. Through experiment, thearticle find out the impact on PZT pump performance which include workingvoltage, valve number, chamber height, chamber number etc. The above data andconclusion offered the experimental basis for design and production of PZT pump.In order to verify the dependability and validity of chip water-cooling systemdriven by PZT pump, a large number of experiment test were carried out in thearticle. The article introduced the test instrument and it's connection type at first,and confirmed the choice of the cooling liquid, hence find out each part's influenceon water-cooling system. Though experiment it was found that the siliconlipoprotein can reduce the contact thermal resistance between the the radiator(heatsink) and computer chip, it can strengthen the ability of heat radiation. From theexperiment it was found that the fan is critical for cooling system. When fantransmits forced air towards radiator, chip's steady temperature is profoundlydecreased, so fan is added to water-cooling system. However, cooling liquid bringsthe heat produced by chip far away the chip, so wind amount needed for chipcooling decreases, so after lowering the fan's rotate speed, chip can be cooledsilently. All of these offered the design direction of water-cooling system andoptimization of each part . It is proved that the water cooling system is efficientthan traditional wind-cooling system by taking the experiment between seperatedand integrated radiator. It was revealed that The integrated radiator can achieveheat balance in about 20 minutes under the circumstance temperature of 19oC,whenthe heat power are 60W, 80W, 100W, and 120W, the corresponding temperatures ofheat balance are 39oC, 45oC, 52oC and 60oC, which can totally meet the coolingrequirements of the computer chip. |
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