界面材料热阻及热传导系数测量装置设计

论文总字数：20235字

摘 要

：电子设备的热设计与电磁兼容之间的冲突主要体现在电磁屏蔽问题上，随着频率的提高，电子设备所处的电磁环境越来越差，另一方面，随着电子设备体积的小型化，导致功率密度的增大，因此电子设备的热设计面临着越来越严峻的考验。屏蔽体在阻隔电磁能量的同时也不可避免的成为阻隔冷却气流的畅通的屏障。因此，很多时候满足电子设备电磁兼容的设计的要求玩玩是以牺牲其热设计的指标为代价而实现的。本次毕设就是要设计出一台能够相对准确的测量出界面材料的热阻以及热传导系数的装置，对于不同的固态材料均能使用。本次毕设的测试方案主要利用热太稳流法测量热阻以及热传导系数，相对于现已有的装置，加入了利用循环水的冷却方式，简单并且容易操作，实用性好，对于测试样本的尺寸也相对的范围增大，可实现对于多种不同尺寸的测量，在外形设计上，采用透明亚克力真空箱，因此可以在实验过程中很好的观察内部的变化以及确保实验的顺利进行，相对原来的非透明的密封容器，操作性大大的提高。箱体采用亚克力材料的好处是，既能够实现透明的要求，又能满足可加工性以及安全性能的条件，还有一点就是，此装置的市场前景，亚克力的造型，外观比较好看，具有一定的观赏性，因而如果后期开发，具有一定的市场前景。对于内部的热源以及冷源，采用固定冷源，活动热源的方法，这样，被测试样的尺寸可以放宽，热源主要是采用电热丝缠绕铜棒的方式，电热丝加热，既能控制电压来实现不同的温度要求，也相对的有一个比较稳定的温度范围。

关键词：界面热阻；热传导系数；真空容器；尺寸变换；循环水。

Interface Material Thermal Resistance And Thermal Conductivity Measuring Dvice Is Designed

Number:02012433 Name:Machenyi

Supervised by Jingshenhui

Abstract: The conflict between compatible thermal and electromagnetic design of electronic equipment mainly in electromagnetic shielding, with increasing frequency, the electronic equipment in which the electromagnetic environment is getting worse, on the other hand, with the volume of electronic equipment miniaturization, leading power density increases, so the thermal design of electronic equipment facing increasingly severe test. Shield the electromagnetic energy of the barrier but also inevitably become blocked cooling air flow barrier. Therefore, a lot of time to meet the electromagnetic compatibility of electronic equipment design requirements to play at the expense of its thermal design of indicators at the expense of implementation. The complete set is able to design a relatively accurate means to measure the thermal resistance and thermal conductivity of the interface material, capable of being used for different solid materials. The complete set of test solutions using mainly hot too steady flow measurement of thermal resistance and thermal conductivity, relative to the conventional apparatus has been added to the use of recycled water cooling method is simple and easy to use, practical, and for the test sample the relative size also increases the range can be realized for many different sizes of measurements, form and design, the use of transparent acrylic vacuum box, it can be well observed change within the course of the experiment and to ensure the smooth progress of the experiment, relative to the original non-transparent sealed container, operability is greatly improved. Benefits box with acrylic materials is not only able to achieve transparency requirements, but also meet the workability and safety conditions, another point is, this means the market prospects, acrylic shape, appearance looks better, has a certain ornamental, so if late development, has a market prospects. For internal heat source and a cold source, fixed source of cold, heat method activity, so the size of the test specimen can be relaxed, the main heat source heating wire is wound way using copper, electric wire heating, both to control the voltage to achieve different temperature requirements, there is a relatively stable temperature range.

Keywords: interfacial thermal resistance; thermal conductivity; vacuum vessel; resizing; circulating water.

目录

目录 1

第一章 绪论 2

1.1 课题背景 2

1.2 发展现状 2

1.3 存在问题及解决途径 3

1.4论文内容及规划 4

第二章 设计方案的理论基础 5

2.1 导热系数的定义 5

2.1.1导热微分方程 5

2.1.2导热系数微分方程的简化： 6

2 测试方法分析与比较 7

2.1 非稳态的测量方法 7

2.1.1热线法基本原理 7

2.1.2 断电热线法测定材料导热系数的原理 8

2.2 稳态的测量方法 10

2.2.1 球体法 10

2.2.2平板法 11

第三章 测试方法的改进 14

3.1 测试模型 14

3.2等效热路图 15

3.2.1导热热阻 15

第四章 测试所用装置 19

4.1 加热装置 19

4.2 真空环境 19

4.2.1真空泵 19

4.2.2单向阀 19

4.3热电偶 19

4.3.1热电偶的工作原理 19

4.3.2热电偶测量端的焊接 20

第五章 整体结构设计 21

5.1 真空箱体结构 21

5.2 执行系统 21

5.3 整体结构三维模型图 22

第六章 实验数据及结论 23

致谢 23

参考文献 24

界面材料热阻及热传导系数测量装置设计

第一章 绪论

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