Measurement of in-plane thermal conductivity of glued graphite film based on thermal imaging

doi:10.11949/0438-1157.20190493

Abstract

Abstract:

Graphite film is widely used in heat dissipation of heat-generating devices in electronic equipment. In-plane thermal conductivity is the key parameter which describes the heat transfer performance. However, currently only the graphite bare material data is provided in the industry, and the glued graphite film cannot be tested. It brings great inconvenience to thermal design and product quality management. In this paper, a thermal imaging-based steady-state test method for the thermal conductivity of glued graphite film is proposed. The sample is directly adhered to the flat surface which is heated by electric heating film. The temperature gradient is integrated along a loop to eliminate the influence of non-uniform thermal flow, and the thermal loss on the surface and bypass are reduced by calibration. Experiments based on a variety of glued graphite film products and metal sheets with reference data verified the validity of the method. The comparison between the test data of the glued graphite film and the bare graphite material parameters showed that great difference may exist, indicating that the nominal performance and actual performance of the graphite film product may be significantly different, and that test on glued graphite film rather than bare material is necessary.

Key words: graphite film, thermal conductivity, thermal imaging, loop integration, thermal loss calibration, steady state, heat transfer, composites

摘要：

导热石墨膜广泛用于电子设备中的发热器件散热，面向热导率是反映其传热性能的关键参数，但目前行业中一般只提供裸材数据，无法对背胶石墨膜进行测试，给石墨膜用户的热设计和产品质量管理带来不便。提出一种基于热成像的背胶石墨膜面向热导率稳态测试方法，样品直接黏附于平整台面测试，通过温度梯度环路积分消除热流不均匀的影响，通过热损失标定减小表面换热和旁路传热带来的测试误差。基于多种规格石墨膜产品和具有参考数据的金属薄片进行实验，结果证明了方法的有效性。背胶石墨膜测试数据和裸材参数的比较表明二者有很大偏差，表明石墨膜产品标称参数和实际参数可能有较大偏差，应用中需直接测试背胶石墨膜参数。

关键词: 石墨膜, 热导率, 热成像, 环路积分, 热损失标定, 稳态, 传热, 复合材料

CLC Number:

TB 941

Dexin HOU,Yue CHEN,Shuliang YE. Measurement of in-plane thermal conductivity of glued graphite film based on thermal imaging[J]. CIESC Journal, 2019, 70(S2): 76-84.

侯德鑫,陈玥,叶树亮. 基于热成像的背胶石墨膜面向热导率测试方法[J]. 化工学报, 2019, 70(S2): 76-84.

Figures/Tables 12

References 31

1	Takasugi H , Teraki S , Kurokawa T , et al . Development of the thin film with high thermal conductivity for power devices[C]// IEEE Components, Packaging and Manufacturing Technology Society. 2014 IEEE 64th Electronic Components and Technology Conference (ECTC). Florida, USA: IEEE, 2014: 1776-1781.
2	姜辉 . 基于石墨烯/铜复合材料的散热薄膜导热性能研究[D]. 南京: 南京航空航天大学, 2017.
	Jiang H . Research on thermal conductance of thin films based on graphene / copper composite[D]. Nanjing: Nanjing University of Aeronautics and Astronautics, 2017.
3	Sharma S , Kumar P , Chandra R . Mechanical and thermal properties of grapheme-carbon nanotube-reinforced metal matrix composites: a molecular dynamics study[J]. Journal of Composite Materials, 2017, 51(23): 3299-3313.
4	周春玉, 曾亮, 吉莉, 等 . 石墨烯及其复合材料导热性能的研究现状[J]. 材料开发与应用, 2010, 25(6): 94-100.
	Zhou C Y , Zeng L , Ji L , et al . Research on the thermal conductivities of graphene and graphene based composite materials[J]. Development and Application of Materials, 2010, 25(6): 94-100.
5	Yan Z , Nika D L , Balandin A A . Thermal properties of graphene and few-layer graphene: applications in electronics[J]. IET Circuits, Devices & Systems, 2015, 9(1): 4-12.
6	张建生, 杨君友, 朱文, 等 . 薄膜热导率测试方法研究进展[J]. 材料导报, 2010, 24(7): 103-107.
	Zhang J S , Yang J Y , Zhu W , et al . Research advances in the measurement for the thermal conductivity of thin solid films[J]. Materials Review, 2010, 24(7): 103-107.
7	刘珊, 徐梁, 曾智强 . 微米级超薄石墨膜的导热性能测试[J]. 炭素, 2017, (4): 42-45.
	Liu S , Xu L , Zeng Z Q . Thermal conductivity testing of thin graphite films[J]. Carbon, 2017, (4): 42-45.
8	厉阳, 侯德鑫, 叶树亮 . 基于热成像的材料热扩散率测量方法研究[J].计量学报, 2017, 38(1): 28-33.
	Li Y , Hou D X , Ye S L . Research on measurement method of thermal diffusivity of materials based on thermography[J]. Acta Metrologica Sinica, 2017, 38(1): 28-33.
9	朱玉祥 . 改进型瞬态平面热源法的实验研究[D]. 青岛: 青岛理工大学, 2015.
	Zhu Y X . Experimental study of improved transient plane source[D]. Qingdao: Qingdao University of Technology, 2015.
10	Ruffio E , Saury D , Petit D . Improvement and comparison of some estimators dedicated to thermal diffusivity estimation of orthotropic materials with the 3D-flash method[J]. International Journal of Heat & Mass Transfer, 2013, 64(64): 1064-1081.
11	Krapez J C , Spagnolo L , Frieß M , et al . Measurement of in-plane diffusivity in non-homogeneous slabs by applying flash thermography[J]. International Journal of Thermal Sciences, 2004, 43(10): 967-977.
12	Forte G , Ronca S . Laser-flash in-plane thermal analysis: the case of oriented UHMWPE[C]// Ⅷ International Conference on “Times of Polymers and Composites”, AIP Conference Proceedings. Naples, Italy: AIP Publishing, 2016, 1736(1): 020171.
13	Zacharia S G , Siddiqui A O , Lahiri J . In situ thermal diffusivity determination of anisotropic composite structures: transverse diffusivity measurement[J]. NDT & E International, 2012, 48: 1-9.
14	Ruoho M , Valset K , Finstad T , et al . Measurement of thin film thermal conductivity using the laser flash method[J]. Nanotechnology, 2015, 26(19): 195706.
15	Ma L , Srivastava R , Barpanda D , et al . An inverse approach to characterize anisotropic thermal conductivities of a dry fibrous preform composite[J]. Journal of Reinforced Plastics & Composites, 2013, 32(24): 1916-1927.
16	Lei Z , Zhu S K , Pan N . Transient methods of thermal properties measurement on fibrous materials[J]. Journal of Heat Transfer, 2010, 132(3): 39-51.
17	江楠竹, 潘江, 王玉刚, 等 . TPS法导热系数测量的仿真分析[J]. 中国测试, 2016, 42(6): 122-126.
	Jiang N Z , Pan J , Wang Y G , et al . Simulation and analysis of thermal conductivity measurement with TPS method[J]. China Measurement & Testing Technology, 2016, 42(6): 122-126.
18	周倩楠 . 石墨烯/碳纳米管/环氧树脂复合材料的导热性能的实验研究[D]. 青岛: 青岛理工大学, 2018.
	Zhou Q N . Experimental study on thermal conductivity of GP / MWCNTs /EP composites[D]. Qingdao: Qingdao University of Technology, 2018.
19	翟德怀 . 基于Hot Disk的薄板材料导热系数测量方法的研究[D]. 广州: 华南理工大学, 2015.
	Zhai D H . Study on the thermal conductivity measurement of thin samples by Hot Disk thermal constants analyser[D]. Guangzhou: South China University of Technology, 2015.
20	Wang Y W , Li Y N . Influence of heat loss through probe electrical leads on thermal conductivity measurement with TPS method[J]. Journal of Measurement Science & Instrumentation, 2018, 9(1): 9-15.
21	Beyerle R , Smalc M , Wayne R , et al . A comparison of methods to measure the thermal diffusivity of anisotropic graphite heat spreaders[C]// Electronic and Photonic Packaging Division, ASME 2013 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems. California, USA: American Society of Mechanical Engineers, 2013: V002T08A022.
22	邓玉杰 . 基于3ω法体块和薄膜材料热物性的研究[D]. 南京: 南京大学, 2016.
	Deng Y J . Study on buification and thin-film thermal properties based on the 3ω method[D]. Nanjing: Nanjing University, 2016.
23	何龙 . 3ω法在薄膜界面热阻测量中的应用[D]. 成都: 电子科技大学, 2016.
	He L . Application of the 3-omega method on measuring the interfacial thermal resistance in thin films[D]. Chengdu: University of Electronic Science and Technology of China, 2016.
24	苏国萍, 唐大伟, 郑兴华, 等 . 3ω方法测量各向异性SiC晶体的导热系数[J]. 工程热物理学报, 2011, 32(11): 1885-1888.
	Su G P , Tang D W , Zheng X H , et al . Determination of thermal conductivity of anisotropic SiC crystal using 3ω method[J]. Journal of Engineering Thermophysics, 2011, 32(11): 1885-1888.
25	Zhu Y . Heat-loss modified Angstrom method for simultaneous measurements of thermal diffusivity and conductivity of graphite sheets: the origins of heat loss in Angstrom method[J]. International Journal of Heat and Mass Transfer, 2016, 92: 784-791.
26	Ras M A , May D , Wunderle B . Novel test stand for thermal diffusivity measurement of bulk and thin films[C]// 2016 22nd International Workshop on Thermal Investigations of ICs and Systems (THERMINIC). Budapest, Hungary: IEEE, 2016: 243-249.
27	Aaron K , Tang X , Tritt T M . Measurement of the in-plane thermal conductivity of single crystals by the parallel thermal conductance technique[C]// ICT 2005 International Conference on Thermoelectrics. SC, USA: IEEE, 2005: 87-90.
28	Teertstra P , Karimi G , Li X . Measurement of in-plane effective thermal conductivity in PEM fuel cell diffusion media[J]. Electrochimica Acta, 2011, 56(3): 1670-1675.
29	Sadeghi E , Djilali N , Bahrami M . A novel approach to determine the in-plane thermal conductivity of gas diffusion layers in proton exchange membrane fuel cells[J]. Journal of Power Sources, 2011, 196(7): 3565-3571.
30	Gholami A , Ahmadi M , Bahrami M . A modified steady state method for measurement of in-plane thermal conductivity[C]// 32nd Thermal Measurement, Modeling & Management Symposium (SEMI-THERM). Alabama, USA: IEEE, 2016: 22-26.
31	蔡北虎, 董德平, 屈金祥 . 国产石墨薄膜低温导热系数测量[J]. 低温工程, 2008, (1): 29-32.
	Cai B H , Dong D P , Qu J X . Measurement of thermal conductivity for home-made graphite sheet at low temperature[J]. Cryogenics, 2008, (1): 29-32.

编号	材料	厚度/mm	面向热导率参考值/( W·m^-1·K^-1)	面向热导率测试值/(W·m^-1·K^-1)	相对偏差/%
1	1060	0.17	234	255	9.0
2	304	0.34	16	17.1	6.7
3	304	0.44	16	16.1	0.7
4	304	0.44	16	16.5	2.9
5	5020	0.46	138	132	-4.0
6	T2	0.58	407	394	-3.1
7	1060	0.46	234	225	-3.8
8	A3	0.49	80	71.8	-10.2
9	H62	0.39	108.9	115	5.7
10	H62	0.48	108.9	108	-0.5
11	T2	0.39	407	386	-5.1
12	T2	0.39	407	400	-1.8
13	1060	0.17	234	255	9.0
14	A3	0.30	80	83.3	4.2

编号	材料	厚度/mm	面向热导率参考值/( W·m^-1·K^-1)	面向热导率测试值/(W·m^-1·K^-1)	相对偏差/%
1	1060	0.17	234	255	9.0
2	304	0.34	16	17.1	6.7
3	304	0.44	16	16.1	0.7
4	304	0.44	16	16.5	2.9
5	5020	0.46	138	132	-4.0
6	T2	0.58	407	394	-3.1
7	1060	0.46	234	225	-3.8
8	A3	0.49	80	71.8	-10.2
9	H62	0.39	108.9	115	5.7
10	H62	0.48	108.9	108	-0.5
11	T2	0.39	407	386	-5.1
12	T2	0.39	407	400	-1.8
13	1060	0.17	234	255	9.0
14	A3	0.30	80	83.3	4.2

石墨膜规格	面向热导率/( W·m^-1·K^-1)
石墨膜规格	测试1	测试2	测试3	均值	标准差	相对标准差/%
17 μm单层背胶	945	977	984	969	20.8	2.1
17 μm双层背胶	529	524	539	531	7.6	1.4
25 μm单层背胶	672	674	667	671	3.6	0.5
25 μm双层背胶	800	829	805	811	15.5	1.9
40 μm单层背胶(A款)	681	663	657	667	12.5	1.9
40 μm单层背胶(B款)	642	660	651	651	9.0	1.4
40 μm双层背胶	725	713	755	731	21.6	3.0

石墨膜规格	面向热导率/( W·m^-1·K^-1)
石墨膜规格	测试1	测试2	测试3	均值	标准差	相对标准差/%
17 μm单层背胶	945	977	984	969	20.8	2.1
17 μm双层背胶	529	524	539	531	7.6	1.4
25 μm单层背胶	672	674	667	671	3.6	0.5
25 μm双层背胶	800	829	805	811	15.5	1.9
40 μm单层背胶(A款)	681	663	657	667	12.5	1.9
40 μm单层背胶(B款)	642	660	651	651	9.0	1.4
40 μm双层背胶	725	713	755	731	21.6	3.0

石墨膜规格	总厚/μm	实测密度/ (kg·m^-3)	密度预测/ (kg·m^-3)	热导率预测/ (W·m^-1·K^-1)	本文测试/ (W·m^-1·K^-1)	相对偏差/%
17 μm单层背胶	35	1785	1424	771	969	23
17 μm双层背胶	90	1002	1308	600	531	-12
25 μm单层背胶	40	1317	1514	874	671	-26
25 μm双层背胶	80	1548	1514	874	811	-7.5
40 μm单层背胶A款	65	1354	1563	901	667	-30
40 μm单层背胶B款	55	1222	1684	1065	651	-48
40 μm双层背胶	125	1467	1590	937	731	-25