Measurement and Characterization of the Moisture-Induced Properties of ACF Package

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Ji-Young Yoon ◽  
Ilho Kim ◽  
Soon-Bok Lee

This study is to observe the exact behavior of anisotropic conductive adhesion (ACF) package under humid environments by obtaining the moisture-induced properties such as diffusion coefficient (the rate of moisture movement into the materials), saturated moisture content (the maximum absorbed quantity), and swelling coefficient (length change due to the chemical interaction). So the experiments were performed to get the moisture-induced properties of ACF and FR4 using newly developed method at various temperature and relative humidity conditions. Experimental results showed that the diffusion coefficient of ACF and FR4 follows Arrhenius’ equation very well, and the saturated moisture content of them follows Henry’s law, which means linear relationship between saturated moisture content and relative humidity, but the saturated moisture content of ACF is influenced by temperature as well as relative humidity. And the swelling coefficient of ACF and FR4 increases with temperature. Especially in the case of ACF, it shows the dramatic degradation due to Tg (glass transition temperature) at nearby 85°C. Finally, as using these experimental results, the behavior of the ACF package under humid environment is predicted through finite element simulation. When wetness defined by moisture content over saturated moisture content changes from 0 to 0.9, the center of the ACF package is subject to compression and the edge of the ACF package is subject to tension in the case of transient state. After all, because the edge of the ACF package is very weak due to bending moment, the failure is easy to occur under humid environment.

1940 ◽  
Vol 18a (6) ◽  
pp. 105-121 ◽  
Author(s):  
J. D. Babbitt

It is pointed out that experimental work has shown that for the transpiration of moisture through hygroscopic materials two distinct regions of relative humidity can be distinguished: (i) A region below some value between 70 and 80% where the moisture movement is proportional to the vapour pressure difference, and (ii) a region of high relative humidity where the moisture movement is not directly proportional to the vapour pressure. A theory is advanced that these two regions correspond to the two conditions in which water may be present in a hygroscopic material: (i) the water may be molecularly adsorbed, that is to say, the water is bound by the affinity of the molecules of water for those of the solid on which it is adsorbed; (ii) the water may be held in small fissures in the sub-microscopic structure of the sorbing material by capillary forces. The mechanism by which the moisture will move through the material would be different in the two cases and would result in the distinction between regions of high and of low relative humidity.A short discussion is given of Fick's law showing the form in which it might be expected to apply in the two cases. Measurements are given for fibreboards showing that below 75% relative humidity the resistance of the board to moisture transpiration is proportional to the thickness. The moisture content gradients through fibreboard samples have been determined. The diffusance through a board in which the moisture content gradient is opposed to the vapour pressure gradient shows that the latter is the important factor, and the determination of the moisture content gradient indicates that at these low humidities Fick's law is applicable.


2012 ◽  
Vol 2 (1) ◽  
pp. 14-20
Author(s):  
Yuwana Yuwana

Experiment on catfish drying employing ‘Teko Bersayap’ solar dryer was conducted. The result of the experiment indicated that the dryer was able to increase ambient temperature up to 44% and decrease ambient relative humidity up to 103%. Fish drying process followed equations : KAu = 74,94 e-0,03t for unsplitted fish and KAb = 79,25 e-0,09t for splitted fish, where KAu = moisture content of unsplitted fish (%), KAb = moisture content of splitted fish (%), t = drying time. Drying of unsplitted fish finished in 43.995 hours while drying of split fish completed in 15.29 hours. Splitting the fish increased 2,877 times drying rate.


2019 ◽  
Vol 6 (6) ◽  
pp. 181902 ◽  
Author(s):  
Junchen Lv ◽  
Yuan Chi ◽  
Changzhong Zhao ◽  
Yi Zhang ◽  
Hailin Mu

Reliable measurement of the CO 2 diffusion coefficient in consolidated oil-saturated porous media is critical for the design and performance of CO 2 -enhanced oil recovery (EOR) and carbon capture and storage (CCS) projects. A thorough experimental investigation of the supercritical CO 2 diffusion in n -decane-saturated Berea cores with permeabilities of 50 and 100 mD was conducted in this study at elevated pressure (10–25 MPa) and temperature (333.15–373.15 K), which simulated actual reservoir conditions. The supercritical CO 2 diffusion coefficients in the Berea cores were calculated by a model appropriate for diffusion in porous media based on Fick's Law. The results show that the supercritical CO 2 diffusion coefficient increases as the pressure, temperature and permeability increase. The supercritical CO 2 diffusion coefficient first increases slowly at 10 MPa and then grows significantly with increasing pressure. The impact of the pressure decreases at elevated temperature. The effect of permeability remains steady despite the temperature change during the experiments. The effect of gas state and porous media on the supercritical CO 2 diffusion coefficient was further discussed by comparing the results of this study with previous study. Based on the experimental results, an empirical correlation for supercritical CO 2 diffusion coefficient in n -decane-saturated porous media was developed. The experimental results contribute to the study of supercritical CO 2 diffusion in compact porous media.


2010 ◽  
Vol 133-134 ◽  
pp. 201-204
Author(s):  
Ibrahim Mohamad H. Wan ◽  
B.H. Abu Bakar ◽  
M.A. Megat Johari ◽  
P.J. Ramadhansyah

This paper presents the behaviour of moisture movement of calcium silicate brick masonry walls exposed to sodium sulphate environment. The walls were exposed to three sodium sulphate conditions with sulphate concentrations of5%, 10% and 15%. For comparison, some walls were also exposed to dry and wet condition which acts as a control conditions. All specimens were prepared and cured under polythene sheet for 14 days in a controlled environmental room and maintained at relative humidity and temperature of 80 ± 5% and 25 ± 2°C, respectively. After the curing period, the specimens were exposed to sodium sulphate as well as drying and water exposures, during which moisture movement was measured and monitored for a period of up to 7 months. As a result, the moisture expansion was observed and recorded for all masonry wall specimens after exposed to the sulphate condition.


Author(s):  
Arun Gupta ◽  
Patrick Jordan ◽  
Shusheng Pang

The hot pressing operation is one of the most important operations in medium density fibreboard (MDF) manufacture. Complicated dynamic interactions occur during pressing, including heat transfer, moisture movement, development of gas pressure, internal stress development and relaxation, wood consolidation, resin curing, bonding between particles and eventual development of a non-uniform density distribution through the panel thickness. Consequently the mat experiences continuously changing internal conditions (temperature and moisture content) as the pressing operation proceeds. The vertical density profile (VDP) has a major influence on the MDF strength and physical properties. This influence of the VDP on the board properties is generally recognised, but the formation of the density profile and their specific effects on the board performance have proved difficult to quantify. A mathematical model based on theoretical analysis and experimental information is being developed. In the model, the mat is divided into a number of thin parallel layers. The deformation of each layer is a function of stress, temperature and moisture content of the layer. The model incorporates the variation of the mat mechanical and rheological properties with moisture content and temperature. The changes in temperature and moisture content are provided by a separate heat and mass transfer model. The present model can predict stress, strain, layer deformation and density across the thickness during pressing. The performance of the model was validated by experiments conducted in a pilot-scale press. Twelve MDF boards were made with different pressing parameters, and the VDP were measured and compared with the simulation results from the model. The model could predict the density profile with an acceptable accuracy for the main variables that control the manufacturing of MDF boards.


2012 ◽  
Vol 531 ◽  
pp. 395-398
Author(s):  
Xiao Fei Sun ◽  
Yu Hui Qiao

Ginkgo seeds were selected and used as experimental material to study protein compositions in ginkgo protein. Ginkgo protein was used as accessory to be added into flour to make bread. Effect of ginkgo protein on moisture content and hardness of bread were investigated. Experimental results showed that ginkgo protein contained water-soluble protein and salt-soluble protein which was 85.28 percents in total protein and contained small amounts of prolamin and alkali-soluble protein. The bread added with different ratios of ginkgo protein had higher moisture content and lower hardness. Therefore, adding appropriate amount of ginkgo protein could improve bread baking performances and bread shelf life.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Lijun Cheng ◽  
Yong Kang ◽  
Guishui Li

Difference between adsorption of benzene by diatomite and nano-TiO2immobilized on diatomite was investigated. And effects of temperature, light intensity, relative humidity, and initial benzene concentration on adsorption and degradation of benzene by nano-TiO2immobilized on diatomite were also studied. The experimental results showed that when initial benzene concentration was2.2×10−3 mg L−1, it could be degraded to below safe concentration (1.1×10−4 mg L−1) after 50 h when temperature was 20°C, but it just needed 30 h at 35°C. When light intensity was 6750 Lx, it needed 30 h for benzene to be degraded to below safe concentration, but benzene could barely be degraded without light. When relative humidity was 50%, benzene could be degraded to1.0×10−4 mg L−1after 30 h, while its concentration could be reduced to7.0×10−5 mg L−1at the relative humidity of 80%.


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