• Title/Summary/Keyword: cure time

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Effect of Die Attach Film Composition for 1 Step Cure Characteristics and Thermomechanical Properties (다이접착필름의 조성물이 1단계 경화특성과 열기계적 물성에 미치는 영향에 관한 연구)

  • Sung, Choonghyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.12
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    • pp.261-267
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    • 2020
  • The demand for faster, lighter, and thinner portable electronic devices has brought about a change in semiconductor packaging technology. In response, a stacked chip-scale package(SCSP) is used widely in the assembly industry. One of the key materials for SCSP is a die-attach film (DAF). Excellent flowability is needed for DAF for successful die attachment without voids. For DAF with high flowability, two-step curing is often required to reduce a cure crack, but one-step curing is needed to reduce the processing time. In this study, DAF composition was categorized into three groups: cure (epoxy resins), soft (rubbers), hard (phenoxy resin, silica) component. The effect of the composition on a cure crack was examined when one-step curing was applied. The die-attach void and flowability were also assessed. The cure crack decreased as the amount of hard components decreased. Die-attach voids also decreased as the amount of hard components decreased. Moreover, the decrease in cure component became important when the amount of hard component was small. The flowability was evaluated using high-temperature storage modulus and bleed-out. A decrease in the amount of hard components was critical for the low storage modulus at 100℃. An increase in cure component and a decrease in hard component were important for the high bleed-out at 120℃(BL-120).

A Study on Food Cure for Stomach Diseases - Focusing on Eumsunjungyo·Singnyojaebyeong, Singnyochanyo - (비위(脾胃)질환의 식치(食治)에 관한 소고(小考) - 『음선정요(飮膳正要)·식료제병(食療諸病)』, 『식료찬요(食療纂要)』를 중심으로 -)

  • Hong, Jin-im
    • Journal of Korean Medical classics
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    • v.29 no.2
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    • pp.1-12
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    • 2016
  • Objectives : This study selected the food ingredients mainly appearing in the stomach-disease-related articles from Eumsunjungyo Singnyojaebyeong and Singnyochanyo, and investigated their effects to turn these data into references for modern people, use the food therapy of ancestors for modern life, and prevent and cure stomach diseases of modern people due to unhealthy lifestyle. Methods : This study selected the stomach-related food therapies from Eumsunjungyo and Singnyochanyo, and organized the therapies by chief virtue, effect, ingredient, and recipe. Also, this study analyzed and investigated characteristics, tastes, and target organs of the food ingredients in the recipes. Results : There are 8 stomach-related recipes among 61 recipes in Eumsunjungyo Singnyojaebyeong, and there are total 34 types of stomach-related recipes in Singnyochanyo including 27 types of BiwiBuBanui Five and 7 types of GutoBuHaeyeokByeonggyeonBiwi fifteen. Both Eumsunjungyo Singnyojaebyeong and Singnyochanyo contains food therapies for diseases due to week stomach. Most recipes in Singnyochanyo uses only food ingredients, whereas most recipes in Eumsunjungyo Singnyojaebyeong uses ingredients which can be used as medicine. Conclusions : The food therapies in Eumsunjungyo Singnyojaebyeong and Singnyochanyo proves that people in all regions have used food to cure diseases from old times. On the other words, people have clinically used the characteristics, tastes, and cooking forms of food ingredients for a long time. Thus, this study can be a reference for creating another food therapy.

Consideration on Fasting Cure as Natural Healing and Holistic Medicine (자연치유와 전인적 의학(Holistic Medicine)으로서의 단식요법(斷食療法)에 관한 고찰)

  • Yun, In-Suk
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.9 no.1
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    • pp.58-66
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    • 2016
  • The purpose of this study is to consider of fasting cure as natural healing and holistic medicine. As a study method, this author conducted a literature review to figure out the history and meaning of fasting found in religious thoughts and studied the cases applying fasting to either mental or physical healing analytically. According to the study results, first, in terms of religious thoughts, fasting plays significant roles mentally, and the act of fasting influences mankind's mind considerably. Second, fasting as a means of humans' mental and physical healing has been playing significant roles as the medical act of natural healing that has been transmitted from a long time ago. As a result, this author has found that fasting cure has great value as holistic medicine based on natural healing. Based on the implications of this study, this researcher expects that this study will be used as fundamental material to provide the directions and grounds of fasting cure as efficient healing in the aspects of holistic medicine exerting effects on chronic disease resulted from habits or diseases caused by stress, a factor that results in many different kinds of diseases in this age.

Post-cure Condition of a Silicone Rubber Material for a LCD Lamp Holder (LCD 램프홀더용 실리콘고무재료의 후가교 조건)

  • Ahn, Won-Sool;Lee, Joon-Man
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.7
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    • pp.1661-1667
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    • 2009
  • Post-cure characteristics of a silicone rubber material which is widely used for a LCD lamp holder were investigated using thermogravimetric analysis (TGA). Research was especially focussed on searching for the optimum post-cure conditions in relation to the practical operation environments. The results showed that incipient volatile temperature(Ti) during the process was considered as the most important factor and, thereby, post-curing for 2hrs at $250^{\circ}C$seemed to be a reasonable condition in the practical view-point. Arrhenius plot of shift factors which were empirically determined from the time-temperature-superposition-principle showed good linearity, exhibiting the post-cure mechanism might be proceeded through single mechanism with activation energy of 108.25kJ/mol.

A Study on the Effect of Reactive Plasticizer (반응성(反應性) 가소제(可塑劑)의 효과(效果)에 관한 연구(硏究))

  • Park, Gun-Rok;Kim, Hong-Sun;Choi, Sei-Young
    • Elastomers and Composites
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    • v.27 no.4
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    • pp.247-254
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    • 1992
  • The purpose of this dissertation is to study the vulcanization characteristics, compression set and other physical properties of NBR vulcanizates according to the various plasticizer and its content. Vulcanization characteristics were investigated by using cure that has obtained by means of rheometer and Mooney viscometer. The result of physical properties, vulcanization characteristics are as fellows. 1. The results of test for optimum cure time in vulcanization characteristics of NBR compounds indicated the rapidity of scorch time according to the increase of amounts of plasticizer. 2. In the test of compression set property, LCR was the best effect. 3. In the test of oil resistance, LCR was the best effect.

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A study on the vulcaniz러on characteristic of combined antioxidants in NR and SBR compounds (NR 및 SBR의 노화방지제(老化防止劑) 병용효과(倂用效果)에 의(依)한 가황특성(加黃特性) 연구(硏究))

  • Choi, Jae-Woon;Lee, Ki-Jong
    • Elastomers and Composites
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    • v.17 no.2
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    • pp.77-90
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    • 1982
  • The purpose of this study is to get comparative results on the combined antioxidant systems comprised of MHPPD with IPPD, MHPPD with PBN and MHIPPD with MB when they are individually added to NR and SBR compound. Vulcanization characterstics and physical properties of the combined antioxidants have been studied by means of the Mooney viscometer, the Monsanto disc rheometer and so on. According to the test results, MHPPD with IPPD system has shown faster cure rate, better optimum cure time and shorter scorch time than other systems. The vulcanizate comprised of the MHPPD with IPPD antioxidant system has taken advantage of heat resistance, fluid resistance and antiozone resistance.

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A Study on the Effectiveness of Occupational Therapy for the Demented Elderly : Centered on the Improvement of the cognition and the Activity of Daily Living (작업요법이 치매노인의 인지기능과 ADL 기능증진에 미치는 영향연구)

  • Lee, Jin-Jeu;Jun, Eun-Suck;Park, Sung-Hark
    • Journal of Korean Physical Therapy Science
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    • v.9 no.2
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    • pp.143-149
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    • 2002
  • Nowadays senile dementia is on the rise as consequence of serious social problem because of it is old aged society by improvement of medical service. However remedial approach is not being done because of we still don't have an infallible cure of dementia and dementia is been hard to cure. Thus it is introduced in this study to the concept of Occupational therapy, which is one of the remedies. I tried to find out which remedy is the best to cure demented elderly and which is been able to use on field. For this study, I applied a developed Occupational therapy program in actual practice. First, I chose nine demented elderly who are lived in 'David's house' located in Daejon metropolitan city, and I separated them in three groups for this study. Second, I applied each Occupational therapy to first and second group, and I did not apply any Occupational therapy to third group. The first and second group was applied the program, two times a week for an hour, for three months. The measurement of Cognitive function was practiced five times - one time before applying the Occupational therapy by MMSE-K, and three times during applying the program, and one time after ending of the program. The measurement of ADL was practiced two times - one time before applying the Occupational therapy by the Barthel ADL, and one time after one month from ending the program. Effectiveness of Occupational therapy and possibility of application of Occupational therapy program are proved because of this study shows the Occupational therapy keeps well the cognitive function and the ADL function of demented elderly, improves those functions, affects positively to the whole life. However we must develop Occupational therapy, which is proper to a trait of character, and expanded application is needed. In addition, temporary remedy must not be performed but continuous cure. This study will be complement by studying about special situation researcher cannot control something like unexpected death of demented elderly by other diseases.

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A STUDY ON THE DEGREE OF CONVERSION OF LIGHT CURING COMPOSITE RESIN ACCORDING TO THE DEPTH OF CURE AND LIGHT CURING TIME (수종 광중합 복합 레진의 중합 깊이와 광조사 시간에 따른 중합률에 관한 연구)

  • Kim, Kyung-Hyun;Kwon, Oh-Sung;Kim, Hyun-Gee;Baek, Kyu-Chul;Um, Chung-Moon;Kwon, Hyuk-Choon
    • Restorative Dentistry and Endodontics
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    • v.22 no.1
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    • pp.35-60
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    • 1997
  • Physical properties of composite resins such as strength, resistance to wear, discoloration, etc, depend on the degree of conversion of the resin components. The clinical behavior of restorative resins varies brand to brand. Part of this variation is associated with the filler and differences in the polymer matrix. The polymer matrix of resins may differ because the involved monomers are dissimilar and because of variation in the catalyst system. The purpose of this study was to evaluate the degree of conversion of the composite resins according to the depth of cure and light curing time. 7mm diameter cylindrical aluminum molds were filled with each of five different hybrid light curing composite resins(Z-100, Charisma, Herculite XRV, Prisma TPH, Veridonfil) on the thin resin films. The molds were 1mm, 2mm, 3mm, 4mm, and 5mm in depth to produce resin films of various heights. Each sample was given 20sec, 40sec, and 60sec illumination with a light source. The degree of conversion of carbon double bonds to single bonds in the resin films was examined by means of Fourier Transform Infrared Spectrometer. The results were obtained as follows; 1. There was difference in the degree of conversion among five light curing composite resins according to the depth of cure for 20sec, 40sec, and 60sec illumination with light source with statistical significance(P<0.05). 2. Five light curing composite resins show lower degree of conversion at surface of the resin than depth of 1mm. 3. The degree of conversion of five light curing composite resins was siginificantly reduced from the maximum for the resin film when the light passed through as little as 1mm of each composite. 4. The degree of conversion of five light curing composite resins decrease significantly at the depth of 4mm, and polymerization was not occured at the depth of 5mm except for Prisma TPH. 5. The degree of conversion of five light curing composite resins was increased with increased light curing time, and there was no significant differences in the degree of conversion above 4mm in Z-100, 3mm in Charisma, and at depth of 5mm in Herculite XRV and Veridonfil(P>0.05).

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EFFECT OF LIGHT SOURCE AND SHADE ON DEPTH OF CURE OF COMPOSITES (중합광원과 레진 색상이 복합레진의 중합깊이에 미치는 영향)

  • Na, Joon-Sok;Jeong, Sun-Wa;Hwang, Yun-Chan;Kim, Sun-Ho;Yun, Chang;Oh, Won-Mann;Hwang, In-Nam
    • Restorative Dentistry and Endodontics
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    • v.27 no.6
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    • pp.561-568
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    • 2002
  • Purpose of this research is estimating polymerization depth of different source of light. XL 3000 for halo-gen light, Apollo 95E for plasma arc light and Easy cure for LED light source were used in this study. Different shade (B1 & A3) resin composites (Esthet-X, Dentsply, U.S.A.) were used to measure depth of cure. 1, 2, and 3 mm thick samples were light cured for three seconds, six seconds or 10 seconds with Apollo 95E and they were light cured with XL-3000 and Easy cure for 10 seconds, 20 seconds, or 40 seconds. Vicker's hardness test carried out after store samples for 24 hours in distilled water. Results were as following. 1. Curing time increases from al1 source of lights, oui$.$ing depth increased(p<0.05). 2. Depth (that except 1mm group and 2mm group which lighten to halogen source of light) deepens in all groups, Vickers hardness decreased(p<0.05). 3. Vicker's hardness of A3 shade composite was lower in all depths more than B1 shade composites in group that do polymerization for 10 seconds and 20 seconds using halogen source of light(p<0.05), but group that do polymerization lot 40 seconds did not show difference(p>0.05). 4. Groups that do polymerization using Plasma arc and LED source of light did not show Vicker's hardness difference according to color at surface and 1mm depth(p>0.05), but showed difference according to color at 2mm and 3mm depth(p<0.05). The results showed that Apollo 95E need more polymerization times than manufacturer's recommendation (3 seconds), and Easy cure need polymerization time of XL-3000 at least.

Effects of Foaming Temperature and Carbon black Content on the Cure Behaviors and Foaming Characteristics of the Natural Rubber Foams (발포온도와 카본블랙 함량이 천연고무 발포체의 가황거동 및 발포특성에 미치는 영향)

  • Choi, Kyo-Chang;Kim, Joon-Hyung;Yoon, Jin-Min;Kim, Soo-Yeon
    • Elastomers and Composites
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    • v.41 no.3
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    • pp.147-156
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    • 2006
  • To investigate the influence of the foaming temperature and carbon black content on the cure behaviors and foaming characteristics of the foams. natural rubber (NR) was foamed at five temperature zones (145, 150, 155, 160 and $165^{\circ}C$) and different feeding ratios of the carbon black. A decreasing trend of the scorch time, $t_{s2}$ and cure time, $t_{90}$ was observed upon increasing foaming temperature and carbon black content. The optimal temperature for vulcanization and foaming of NRs in this study was considered to be $165^{\circ}C$ where density of the loomed NRs is lower than those at other four temperature regions. The rule rate index of the NRs foamed at $145^{\circ}C$ is smaller than those at 150, 155, 160 and $165^{\circ}C$. The results of the expansion ratio and micrographs of the foamed NRs were founded to support the density characteristics. The thickness of each of the struts formed inside the rubber matrix decreases with increasing the foaming temperature, while it increases with increasing the carbon black content.