Pub Date : 1988-05-11DOI: 10.1109/ITHERM.1988.28673
G. Titinet, G. Manzone
Summary form only given. Thermal resistance measurements have been carried out on more than 50 devices with an in-house developed instrument, using the well-known electrical method based on temperature dependence of the Schottky junction forward voltage. The selected MESFETs, intentionally chosen with completely different layout and heat-sinking solutions, such as via-hole or air-bridge source contacts and flip-chip or backside mounting, have been measured at several temperatures and power levels. Present experimental results have been related to the different device structures available and have been compared with theoretical values coming from simplified models proposed in the literature. The results show that the exact location of heat-source areas and the description of heat transfer processes cannot be easily handled with a simple model without a considerable loss of accuracy. The quality of die-attach also has a relevant influence on the value of thermal resistance, essentially due to the presence of voids in the die-attach alloy.<>
{"title":"Thermal resistance measurements and reliability of GaAs power MESFETs","authors":"G. Titinet, G. Manzone","doi":"10.1109/ITHERM.1988.28673","DOIUrl":"https://doi.org/10.1109/ITHERM.1988.28673","url":null,"abstract":"Summary form only given. Thermal resistance measurements have been carried out on more than 50 devices with an in-house developed instrument, using the well-known electrical method based on temperature dependence of the Schottky junction forward voltage. The selected MESFETs, intentionally chosen with completely different layout and heat-sinking solutions, such as via-hole or air-bridge source contacts and flip-chip or backside mounting, have been measured at several temperatures and power levels. Present experimental results have been related to the different device structures available and have been compared with theoretical values coming from simplified models proposed in the literature. The results show that the exact location of heat-source areas and the description of heat transfer processes cannot be easily handled with a simple model without a considerable loss of accuracy. The quality of die-attach also has a relevant influence on the value of thermal resistance, essentially due to the presence of voids in the die-attach alloy.<<ETX>>","PeriodicalId":226424,"journal":{"name":"InterSociety Conference on Thermal Phenomena in the Fabrication and Operation of Electronic Components. I-THERM '88","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115417108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-05-11DOI: 10.1109/ITHERM.1988.28670
L. Rottiers, G. De Mey
A model is presented to investigate the hot-spot effect, occurring at the termination point of a trimming out in screen-printed resistors. The phenomenon is studied by means of a potential problem to calculate the electrical field in the resistor, for which a 2D thermal model, and a 3D thermal model have been built up. The steady-state behavior and the transient behavior are presented. Several examples show the usefulness of computer simulations to solve thermal problems especially in the case of the trimmed resistor.<>
{"title":"Simulation of thermal behaviour in hybrid circuits","authors":"L. Rottiers, G. De Mey","doi":"10.1109/ITHERM.1988.28670","DOIUrl":"https://doi.org/10.1109/ITHERM.1988.28670","url":null,"abstract":"A model is presented to investigate the hot-spot effect, occurring at the termination point of a trimming out in screen-printed resistors. The phenomenon is studied by means of a potential problem to calculate the electrical field in the resistor, for which a 2D thermal model, and a 3D thermal model have been built up. The steady-state behavior and the transient behavior are presented. Several examples show the usefulness of computer simulations to solve thermal problems especially in the case of the trimmed resistor.<<ETX>>","PeriodicalId":226424,"journal":{"name":"InterSociety Conference on Thermal Phenomena in the Fabrication and Operation of Electronic Components. I-THERM '88","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125444215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-05-11DOI: 10.1109/ITHERM.1988.28677
H. Miura, A. Nishimura, S. Kawai, W. Nakayama
Temperature distribution in the packages is evaluated by both experimental method and an analytical finite-element method (FEM). It is found that the FEM analysis is useful for the temperature estimation of the packages. Temperature sensors imbedded in silicon chips were used to measure the temperature distribution in the package in both the reflow soldering process and the dip-coating process. These sensor chips were encapsulated in the actual DIP (dual in-line package) type package and SOJ (small outline j-bend package) type package. Temperature distributions of these packages were measured under various soldering conditions.<>
{"title":"Temperature distribution in IC plastic packages in the reflow soldering process","authors":"H. Miura, A. Nishimura, S. Kawai, W. Nakayama","doi":"10.1109/ITHERM.1988.28677","DOIUrl":"https://doi.org/10.1109/ITHERM.1988.28677","url":null,"abstract":"Temperature distribution in the packages is evaluated by both experimental method and an analytical finite-element method (FEM). It is found that the FEM analysis is useful for the temperature estimation of the packages. Temperature sensors imbedded in silicon chips were used to measure the temperature distribution in the package in both the reflow soldering process and the dip-coating process. These sensor chips were encapsulated in the actual DIP (dual in-line package) type package and SOJ (small outline j-bend package) type package. Temperature distributions of these packages were measured under various soldering conditions.<<ETX>>","PeriodicalId":226424,"journal":{"name":"InterSociety Conference on Thermal Phenomena in the Fabrication and Operation of Electronic Components. I-THERM '88","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122017985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-05-11DOI: 10.1109/ITHERM.1988.28697
S. Abrahamson, D. Koga, J. Eaton
An experimental simulation of the fluid mechanics of a rigid disk drive has been performed matching the geometry and Ekman number of a full-size (14 in.) disk drive. Three different flow configurations have been studied. The first was a simplified geometry used to determine the basic structure of the flow. The second case explored the effect of the introduction of cooling flow into the basic geometry, and the third considered the separate effect of the blockage due to the presence of the supports for the read heads. All three cases exhibited flow regimes near the rotating hub which were distinct from the flow farther from the hub. In addition, each of the flow configurations contained features not found in the other cases. The implications of these flow features with respect to disk drive performance are discussed.<>
{"title":"Flow visualization and spectral measurements in a simulated rigid disk drive","authors":"S. Abrahamson, D. Koga, J. Eaton","doi":"10.1109/ITHERM.1988.28697","DOIUrl":"https://doi.org/10.1109/ITHERM.1988.28697","url":null,"abstract":"An experimental simulation of the fluid mechanics of a rigid disk drive has been performed matching the geometry and Ekman number of a full-size (14 in.) disk drive. Three different flow configurations have been studied. The first was a simplified geometry used to determine the basic structure of the flow. The second case explored the effect of the introduction of cooling flow into the basic geometry, and the third considered the separate effect of the blockage due to the presence of the supports for the read heads. All three cases exhibited flow regimes near the rotating hub which were distinct from the flow farther from the hub. In addition, each of the flow configurations contained features not found in the other cases. The implications of these flow features with respect to disk drive performance are discussed.<<ETX>>","PeriodicalId":226424,"journal":{"name":"InterSociety Conference on Thermal Phenomena in the Fabrication and Operation of Electronic Components. I-THERM '88","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116290532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-05-11DOI: 10.1109/ITHERM.1988.28699
B. Royce
Structures used in microelectronics systems, ranging in size from the individual device level to complete printed circuit boards (PCBs) involve ceramic, metallic and polymeric materials in intimate physical contact. Thermal cycling during normal operation can give rise to thermal fatigue at the various material interfaces, cause defect propagation, and lead to premature failure of the structures, either directly or through subsequent environmental degradation. The author reviews this technologically important problem by taking examples from each of the 'packaging levels' of microelectronic systems. The examples used include silicon oxidation and GaAs-on-silicon heteroepitaxy, ceramic or polymeric encapsulants of fabricated structures, PCBs, and on the solder connections used in mounting components on PCBs.<>
{"title":"Differential thermal expansion in microelectronic systems","authors":"B. Royce","doi":"10.1109/ITHERM.1988.28699","DOIUrl":"https://doi.org/10.1109/ITHERM.1988.28699","url":null,"abstract":"Structures used in microelectronics systems, ranging in size from the individual device level to complete printed circuit boards (PCBs) involve ceramic, metallic and polymeric materials in intimate physical contact. Thermal cycling during normal operation can give rise to thermal fatigue at the various material interfaces, cause defect propagation, and lead to premature failure of the structures, either directly or through subsequent environmental degradation. The author reviews this technologically important problem by taking examples from each of the 'packaging levels' of microelectronic systems. The examples used include silicon oxidation and GaAs-on-silicon heteroepitaxy, ceramic or polymeric encapsulants of fabricated structures, PCBs, and on the solder connections used in mounting components on PCBs.<<ETX>>","PeriodicalId":226424,"journal":{"name":"InterSociety Conference on Thermal Phenomena in the Fabrication and Operation of Electronic Components. I-THERM '88","volume":"250 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123262041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-05-11DOI: 10.1109/ITHERM.1988.28689
R. Jaeger, F. Gaensslen
The authors consider that, at any technology level, operation at liquid nitrogen temperature (LNT: 77.3 K) can directly yield a performance improvement exceeding that provided through down-scaling by a factor of two. Thus, MOS technology limits are extended by one generation through LNT operation. Because of its attractive speed, density, and power attributes, liquid-nitrogen-cooled CMOS represents a strategic technology alternative for mainframe computers, an area which has traditionally been the exclusive domain of bipolar technology. A summary of the advantages for MOS microelectronics operated at LNT is presented in a table and discussed.<>
{"title":"Low temperature semiconductor electronics","authors":"R. Jaeger, F. Gaensslen","doi":"10.1109/ITHERM.1988.28689","DOIUrl":"https://doi.org/10.1109/ITHERM.1988.28689","url":null,"abstract":"The authors consider that, at any technology level, operation at liquid nitrogen temperature (LNT: 77.3 K) can directly yield a performance improvement exceeding that provided through down-scaling by a factor of two. Thus, MOS technology limits are extended by one generation through LNT operation. Because of its attractive speed, density, and power attributes, liquid-nitrogen-cooled CMOS represents a strategic technology alternative for mainframe computers, an area which has traditionally been the exclusive domain of bipolar technology. A summary of the advantages for MOS microelectronics operated at LNT is presented in a table and discussed.<<ETX>>","PeriodicalId":226424,"journal":{"name":"InterSociety Conference on Thermal Phenomena in the Fabrication and Operation of Electronic Components. I-THERM '88","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131517351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-05-11DOI: 10.1109/ITHERM.1988.28700
F. G. Allen
Thermally activated processes control nearly all steps in the cleaning, growth and doping of molecular-beam-grown epitaxial films. The temperature dependence of five such processes important in the emerging technology of MBE growth of silicon and germanium films is discussed: (1) SiO/sub 2/ removal in the initial cleaning of the substrate, (2) surface diffusion during normal MBE growth, (3) the 'sticking' coefficient of dopants evaporated during growth, (4) the process of solid phase epitaxial regrowth and (5) thermal relief of strain in Si-Ge strained superlattices.<>
{"title":"Thermal phenomena in silicon-germanium molecular beam epitaxial growth","authors":"F. G. Allen","doi":"10.1109/ITHERM.1988.28700","DOIUrl":"https://doi.org/10.1109/ITHERM.1988.28700","url":null,"abstract":"Thermally activated processes control nearly all steps in the cleaning, growth and doping of molecular-beam-grown epitaxial films. The temperature dependence of five such processes important in the emerging technology of MBE growth of silicon and germanium films is discussed: (1) SiO/sub 2/ removal in the initial cleaning of the substrate, (2) surface diffusion during normal MBE growth, (3) the 'sticking' coefficient of dopants evaporated during growth, (4) the process of solid phase epitaxial regrowth and (5) thermal relief of strain in Si-Ge strained superlattices.<<ETX>>","PeriodicalId":226424,"journal":{"name":"InterSociety Conference on Thermal Phenomena in the Fabrication and Operation of Electronic Components. I-THERM '88","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127569484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-05-11DOI: 10.1109/ITHERM.1988.28693
P. Eibeck, D. Cohen
The thermal characteristics of an IMB 5.25-in fixed disk drive were experimentally determined to aid in the development of a general disk drive model. In general, the thermal model was able to predict the transient temperature profiles. At 4000 r.p.m., the steady-state temperature of the air and arms were predicted within 0.4 degrees C, and the base temperature was predicted within 2.4 degrees C. The air temperature was found to be uniform within experimental uncertainty outside of the disk stack, but was 1.4 degrees C higher between corotating disks. The temperature predictions are extremely sensitive to the external heat transfer coefficients and the heat sources in put by the user. It was found that more fundamental information regarding viscous dissipation and air flow within a disk drive must be known to produce a reliable thermal model.<>
{"title":"Thermal characteristics of a fixed disk drive","authors":"P. Eibeck, D. Cohen","doi":"10.1109/ITHERM.1988.28693","DOIUrl":"https://doi.org/10.1109/ITHERM.1988.28693","url":null,"abstract":"The thermal characteristics of an IMB 5.25-in fixed disk drive were experimentally determined to aid in the development of a general disk drive model. In general, the thermal model was able to predict the transient temperature profiles. At 4000 r.p.m., the steady-state temperature of the air and arms were predicted within 0.4 degrees C, and the base temperature was predicted within 2.4 degrees C. The air temperature was found to be uniform within experimental uncertainty outside of the disk stack, but was 1.4 degrees C higher between corotating disks. The temperature predictions are extremely sensitive to the external heat transfer coefficients and the heat sources in put by the user. It was found that more fundamental information regarding viscous dissipation and air flow within a disk drive must be known to produce a reliable thermal model.<<ETX>>","PeriodicalId":226424,"journal":{"name":"InterSociety Conference on Thermal Phenomena in the Fabrication and Operation of Electronic Components. I-THERM '88","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124187587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-05-11DOI: 10.1109/ITHERM.1988.28695
J. Toor
Summary form only given, as follows. Many drives with either 3.5-in or 5.25-in disks operate without any position feedback mechanism and required that materials used within the drive have carefully controlled coefficients of thermal expansion. Completely eliminating thermal offtrack by simply selecting from available materials is often not possible. A method of fine-tuning the offtrack is presented. The method involves adjusting the relative thickness of materials used in a bimetallic composite structure to provide the expansion desired. A computer model predicts results within the drive and a comparison is made of analytic and experimental results. In addition, an overview of the causes of offtrack under both thermal transient and steady-state conditions is presented.<>
{"title":"Use of composite structure to achieve variable rates of thermal expansion in disk drive arms","authors":"J. Toor","doi":"10.1109/ITHERM.1988.28695","DOIUrl":"https://doi.org/10.1109/ITHERM.1988.28695","url":null,"abstract":"Summary form only given, as follows. Many drives with either 3.5-in or 5.25-in disks operate without any position feedback mechanism and required that materials used within the drive have carefully controlled coefficients of thermal expansion. Completely eliminating thermal offtrack by simply selecting from available materials is often not possible. A method of fine-tuning the offtrack is presented. The method involves adjusting the relative thickness of materials used in a bimetallic composite structure to provide the expansion desired. A computer model predicts results within the drive and a comparison is made of analytic and experimental results. In addition, an overview of the causes of offtrack under both thermal transient and steady-state conditions is presented.<<ETX>>","PeriodicalId":226424,"journal":{"name":"InterSociety Conference on Thermal Phenomena in the Fabrication and Operation of Electronic Components. I-THERM '88","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116034235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-05-11DOI: 10.1109/ITHERM.1988.28688
A. Bergles, C. Kim
It is demonstrated that the generation of vapor below a heated surface is an effective means of reducing the large superheat required for inception of boiling with liquids suitable for direct-immersion cooling of microelectronic devices. In experiments with R-113 and a plain copper heat sink surface, the incipient boiling superheat was reduced from 33 K to as low as 8 K. With sintered boiling surfaces, the incipient boiling superheat was reduced from 22 K to as low as 7 K. A reasonable explanation for the effectiveness of this sparging technique is that the impacting bubbles activate temporarily dormant cavities that, in turn, activate large neighboring cavities. The technique appears to be easily adaptable to liquid incapsulated modules containing arrays of microelectronic devices such as chips.<>
{"title":"A method to reduce temperature overshoots in immersion cooling of microelectronic devices","authors":"A. Bergles, C. Kim","doi":"10.1109/ITHERM.1988.28688","DOIUrl":"https://doi.org/10.1109/ITHERM.1988.28688","url":null,"abstract":"It is demonstrated that the generation of vapor below a heated surface is an effective means of reducing the large superheat required for inception of boiling with liquids suitable for direct-immersion cooling of microelectronic devices. In experiments with R-113 and a plain copper heat sink surface, the incipient boiling superheat was reduced from 33 K to as low as 8 K. With sintered boiling surfaces, the incipient boiling superheat was reduced from 22 K to as low as 7 K. A reasonable explanation for the effectiveness of this sparging technique is that the impacting bubbles activate temporarily dormant cavities that, in turn, activate large neighboring cavities. The technique appears to be easily adaptable to liquid incapsulated modules containing arrays of microelectronic devices such as chips.<<ETX>>","PeriodicalId":226424,"journal":{"name":"InterSociety Conference on Thermal Phenomena in the Fabrication and Operation of Electronic Components. I-THERM '88","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132139538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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