IEEE Transactions on Components and Packaging Technologies最新文献

{"title":"Thermal Potential of Flat Evaporator Miniature Loop Heat Pipes for Notebook Cooling","authors":"R. Singh, A. Akbarzadeh, M. Mochizuki","doi":"10.1109/TCAPT.2009.2031875","DOIUrl":"https://doi.org/10.1109/TCAPT.2009.2031875","url":null,"abstract":"Thermal management of laptops is an increasingly challenging task because of the high-heat flux associated with the microprocessors and the limited space available for the thermal control system inside the cabinet. In this paper, results are discussed from an investigation of two different designs of miniature loop heat pipes (mLHPs) for thermal control of compact electronic devices including notebooks. Two prototypes of mLHP, one with a disk-shaped evaporator, 30 mm diameter and 10 mm thick, and the other with a rectangular-shaped evaporator, 47 × 37 mm2 plan area and 5 mm thick, were designed to handle heat fluxes up to 50 W/cm2. In the disk-shaped evaporator, the compensation chamber was incorporated into the overall thickness of the evaporator, whereas for the rectangular-shaped evaporator a new design approach was used in which the compensation chamber was positioned on the sides of the wick structure such that it was coplanar with the evaporator section. The new design approach helped to decrease the thickness of the rectangular evaporator by 50% and therefore improved the ability to integrate miniature loop heat pipe technology into compact electronics enclosures. All of the thermal tests on mLHP prototypes were conducted in horizontal configurations. Total thermal resistance of the designed mLHPs was between 1 and 5° C/W. A comparative study of the mLHPs with conventional heat pipe and microchannel-based active liquid cooling systems has shown the superior heat transfer capability of the passively operating loop scheme for high-heat flux applications, and helped to classify mLHPs as candidates for laptop thermal management.","PeriodicalId":55013,"journal":{"name":"IEEE Transactions on Components and Packaging Technologies","volume":"8 1","pages":"32-45"},"PeriodicalIF":0.0,"publicationDate":"2010-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TCAPT.2009.2031875","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62519607","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}

{"title":"Scaling and Optimization of Gravure-Printed Silver Nanoparticle Lines for Printed Electronics","authors":"D. Sung, A. de la Fuente Vornbrock, V. Subramanian","doi":"10.1109/TCAPT.2009.2021464","DOIUrl":"https://doi.org/10.1109/TCAPT.2009.2021464","url":null,"abstract":"Printed electronics promises to enable new applications such as RFID tags, displays and various types of sensors. Critical to the development of printed electronics is the establishment of a manufacturable printing technique with high resolution and throughput. Gravure is a high-speed roll-to-roll printing technique that has many of the characteristics necessary for a viable printed electronics process. We present the first systematic study on the scaling and optimization of conductive lines for printed electronics, especially with high viscosity nanoparticle inks. We demonstrate gravure-printed nanoparticle lines, which are potentially suitable for use in thin-film transistor (TFT) based circuits as well as passive components. We present several trends observed by varying cell and ink parameters, and compare two different techniques for printing lines. We examine current limits to scaling printed lines and demonstrate the potential viability and scalability of gravure for printed electronics.","PeriodicalId":55013,"journal":{"name":"IEEE Transactions on Components and Packaging Technologies","volume":"33 1","pages":"105-114"},"PeriodicalIF":0.0,"publicationDate":"2010-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TCAPT.2009.2021464","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62519687","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}

{"title":"Conductively Cooled 1 kW—QCW Diode Laser Stacks Enabling Simple Fiber Coupling","authors":"W. Pittroff, G. Erbert, B. Eppich, C. Fiebig, K. Vogel, G. Traenkle","doi":"10.1109/TCAPT.2009.2033120","DOIUrl":"https://doi.org/10.1109/TCAPT.2009.2033120","url":null,"abstract":"A new mini-bar design densely packed with 13 emitters in a 1.6 mm aperture has been developed. These mini-bars deliver >200 W output. With a very low divergence of 95% power enclosed in 25° they are suitable for fast axis collimation (FAC) lenses with large working distance. The mini-bars are mounted on compact CuW carriers, which are further integrated into a custom stack assembly where they are conductively cooled from both sides. This completely AuSn soldered stack consists of only coefficient of thermal expansion matched materials and was 100 times temperature cycled from -40°C to 85°C, without any change in the PUI characteristic, the spectrum and the far field. The beam propagation factor M 2 of a 12-layer stack is ¿130 in the vertical direction (after FAC) and ¿210 in the lateral direction. Thus, the stack can be coupled to a 1.2 mm multi-mode fiber (M 2 = 260) with a coupling efficiency of 90% using only low-cost lenses.","PeriodicalId":55013,"journal":{"name":"IEEE Transactions on Components and Packaging Technologies","volume":"33 1","pages":"206-214"},"PeriodicalIF":0.0,"publicationDate":"2010-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TCAPT.2009.2033120","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62520195","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}

{"title":"Silver Joints Between Silicon Chips and Copper Substrates Made by Direct Bonding at Low-Temperature","authors":"P. Wang, C.C. Lee","doi":"10.1109/TCAPT.2009.2031631","DOIUrl":"https://doi.org/10.1109/TCAPT.2009.2031631","url":null,"abstract":"In this paper, pure silver (Ag) joints between silicon (Si) chips and copper (Cu) substrates are produced successfully at a temperature much lower than its melting point. Silver is ductile and has low-yield strength. It can deform to release the shear stress caused by the large mismatch in coefficient of thermal expansion between Si and Cu. Silver also has the highest electrical conductivity and thermal conductivity among metals. As a bonding medium and interconnect material, it can provide the best electrical and thermal performances. In experiments, Ag in the form of foil is chosen as the bonding medium. Prior to bonding, the Si chips are coated with thin Cr and Au layers. The Si chip, Ag foil, and Cu substrate are bonded together in one step. The bonding process is conducted at 250°C in 50-mtorr vacuum environment. There is no molten phase involved during the bonding process. The resulting joints exhibit nearly perfect quality. No voids are observed at the Si/Ag and Ag/Cu bonding interfaces. The bonding strengths at these two bonding interfaces pass MIL-STD-883G standards. We believe that the bonds at the Au/Ag and Ag/Cu interfaces are formed by short-range interdiffusion. Since the melting point of Ag is 961°C , the Ag joints are expected to sustain high-temperature. The 250°C bonding temperature is the typical reflow temperature of Sn3.5Ag solders used in electronic industries. This novel bonding process can be applied to various electronic devices that require high-thermal performance or high-operation temperature. It is particularly valuable to packaging high-temperature devices.","PeriodicalId":55013,"journal":{"name":"IEEE Transactions on Components and Packaging Technologies","volume":"33 1","pages":"10-15"},"PeriodicalIF":0.0,"publicationDate":"2010-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TCAPT.2009.2031631","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62519514","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}

{"title":"Superlattice $mu {rm TEC}$ Hot Spot Cooling","authors":"V. Litvinovitch, Peng Wang, A. Bar-Cohen","doi":"10.1109/TCAPT.2009.2032297","DOIUrl":"https://doi.org/10.1109/TCAPT.2009.2032297","url":null,"abstract":"Proposed uses of solid-state thermoelectric microcoolers for hot spot remediation have included the formation of a superlattice layer on the back of the microprocessor chip, but there have been few studies on the cooling performance of such devices. This paper provides the results of 3-D, electrothermal, finite element modeling of a superlattice microcooler, focusing on the hot spot temperature and superlattice surface temperature reductions, respectively. Simulated temperature distributions and heat flow patterns in the silicon, associated with variations in microcooler geometry, chip thickness, hot spot size, hot spot heat flux, and superlattice thickness are provided. Comparison is made to hot spot cooling achieved by the Peltier effect in the silicon microprocessor chip itself. The numerical results suggest that, for a variety of operating conditions and geometries, while increasing the superlattice thickness serves to decrease the exposed superlattice surface temperature, it is ineffective in reducing the hot spot temperature below that due to the silicon Peltier effect.","PeriodicalId":55013,"journal":{"name":"IEEE Transactions on Components and Packaging Technologies","volume":"33 1","pages":"229-239"},"PeriodicalIF":0.0,"publicationDate":"2010-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TCAPT.2009.2032297","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62519658","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}

{"title":"Comparison of Micro-Pin-Fin and Microchannel Heat Sinks Considering Thermal-Hydraulic Performance and Manufacturability","authors":"Benjamin A. Jasperson, Y. Jeon, Kevin T. Turner, F. Pfefferkorn, W. Qu","doi":"10.1109/TCAPT.2009.2023980","DOIUrl":"https://doi.org/10.1109/TCAPT.2009.2023980","url":null,"abstract":"This paper explores the potential of micro-pin-fin heat sinks as an effective alternative to microchannel heat sinks for dissipating high heat fluxes from small areas. The overall goal is to compare microchannel and micro-pin-fin heat sinks based on three metrics: thermal performance, hydraulic performance, and cost of manufacturing. The channels and pins of the microchannel and micro-pin-fin heat sinks, respectively, have a width of 200 ¿m and a height of 670 ¿m. A comparison of the thermal-hydraulic performance shows that the micro-pin-fin heat sink has a lower convection thermal resistance at liquid flow rates above approximately 60 g/min, though this is accompanied by a higher pressure drop. Methods that could feasibly fabricate the two heat sinks are reviewed, with references outlining current capabilities and limitations. A case study on micro-end-milling of the heat sinks is included. This paper includes equations that separate the fabrication cost into the independent variables that contribute to material cost, machining cost, and machining time. It is concluded that, with micro-end-milling, the machining time is the primary factor in determining cost, and, due to the additional machining time required, the micro-pin-fin heat sinks are roughly three times as expensive to make. It is also noted that improvements in the fabrication process, including spindle speed and tool coatings, will decrease the difference in cost.","PeriodicalId":55013,"journal":{"name":"IEEE Transactions on Components and Packaging Technologies","volume":"33 1","pages":"148-160"},"PeriodicalIF":0.0,"publicationDate":"2010-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TCAPT.2009.2023980","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62519390","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}

{"title":"Residual Strain Measurement of Thin-Layer Cured Adhesives and Their Effects on Warpage in Electronic Packaging","authors":"M. Tsai, C. Chiang, Chen-Yu Huang, Sheng-Shu Yang","doi":"10.1109/TCAPT.2009.2026471","DOIUrl":"https://doi.org/10.1109/TCAPT.2009.2026471","url":null,"abstract":"Residual strains (stresses) of thin-layer adhesives are important and need be determined and further analyzed for better reliability design of the joints or bump joints in electronic or optoelectronic packaging. The purposes of this paper are to quantify residual strains of two adhesives: A (paste type) and B (film type) due to chemical shrinkage, stress relaxation, and thermal-loadings and moisture-loadings, and to investigate their effects on the warpage of die attachment assembly. At the beginning, the mechanical properties of the two adhesives in terms of temperatures are measured by dynamic mechanical analyzer (DMA) and thermomechanical analyzer (TMA). The residual strains are documented by testing fully cured adhesive/silicon bi-material plates under thermal and moisture loading using Twyman-Green (T/G) interferometry system associated with Timoshenko's bi-material theory and finite element method (FEM). Furthermore, the warpage of silicon/adhesive/Cu tri-material plates (similar to die attachment assembly) with both adhesives under thermal and moisture loading are also investigated by T/G experiments and confirmed by Suhir's solution and FEM results. For adhesive-A, the results of the bi-material plate suggest that the residual strains are only induced by mismatch of the coefficients of thermal expansion during thermal loading, rather than other factors, right after the fully cured adhesive cooling down to room temperature. On the other hand, for adhesive-B, it was found that the additional residual strain of this film adhesive caused by chemical shrinkage plus stress relaxation, is about 2.26 ? 10-3, which accounts for 85% of thermal-residual strains in the bi-material plate from curing temperature cooling down to room temperature. Experimental results also indicated that moisture-absorption expansion of the both adhesives is the major cause of decreasing warpage for the bi-material plates at 29?C/55% RH, other than stress relaxation. In contrast to the results of the bi-material plate, the warpages of the tri-material plates are found to be insensitive to the moisture-absorption, chemical, and thermal strains of adhesives, but not to elastic moduli of adhesives, due to their relatively thin-layer and compliant nature. This paper has successfully laid down an approach for determining residual strain of thin-layer adhesive and provided information about their effect on warpage of die attachment assembly.","PeriodicalId":55013,"journal":{"name":"IEEE Transactions on Components and Packaging Technologies","volume":"23 1","pages":"71-78"},"PeriodicalIF":0.0,"publicationDate":"2010-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TCAPT.2009.2026471","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62519632","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}

{"title":"Predictive Model Development for Life Prediction of PBGA Packages With SnAgCu Solder Joints","authors":"K. Tunga, S. Sitaraman","doi":"10.1109/TCAPT.2009.2032924","DOIUrl":"https://doi.org/10.1109/TCAPT.2009.2032924","url":null,"abstract":"A fatigue model to predict the number of cycles for crack initiation and crack growth rate in Sn4.0Ag0.5Cu solder joints used in plastic ball grid array packages when subjected to accelerated thermal cycling has been developed. In addition to the conventionally used damage metrics such as accumulated strain and accumulated work, the normal strain in the solder joints has also been taken into consideration for fatigue model development. Unlike traditional fatigue models, which equate the life of the package to the life of the critical solder joint, the fatigue life of the package has been estimated by factoring in the reliability and hence the fatigue life of all the solder joints in the package. Good agreement was observed between the estimated package fatigue life from the fatigue model and the fatigue life as determined from experiments.","PeriodicalId":55013,"journal":{"name":"IEEE Transactions on Components and Packaging Technologies","volume":"33 1","pages":"84-97"},"PeriodicalIF":0.0,"publicationDate":"2010-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TCAPT.2009.2032924","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62520118","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}

{"title":"Light Weight High Performance Thermal Management With Advanced Heat Sinks and Extended Surfaces","authors":"T. Icoz, M. Arik","doi":"10.1109/TCAPT.2009.2026736","DOIUrl":"https://doi.org/10.1109/TCAPT.2009.2026736","url":null,"abstract":"Thermal management is a critical and essential component of maintaining high efficiency and reliability of electronic components. Adequate cooling must be provided while meeting the weight and volumetric requirements, especially for passive air-cooling solutions in avionics applications where space and weight are at a premium. It should be noted that there are electronic systems where thermal solution contributes 95% or more to the total weight of the system. With recent advancements in material science and increase in demand for more aggressive cooling solutions, it has become critical to invent, manufacture, characterize, and implement advanced thermal materials for the design of compact and low weight systems. However, because of the complexity due to anisotropic properties of these materials, their thermal performances and reliability are yet to be fully understood. The present paper aims at characterization of advanced thermal materials in passive air-cooling applications. A combined computational and experimental investigation is performed on various advanced heat sink materials and manufactured prototypes. Results are compared with the traditionally used aluminum heat sink and showed that significant weight savings can potentially be achieved. A composite figure of merit is proposed for measuring mass effective cooling capabilities of heat sinks. It is defined as the cooling performance per unit mass of heat sink and shown that advanced materials can perform as much as ten times better than conventional aluminum heat sinks.","PeriodicalId":55013,"journal":{"name":"IEEE Transactions on Components and Packaging Technologies","volume":"33 1","pages":"161-166"},"PeriodicalIF":0.0,"publicationDate":"2010-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TCAPT.2009.2026736","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62519276","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}

{"title":"Constructal Microchannel Network for Flow Boiling in a Disc-Shaped Body","authors":"X. Daguenet-Frick, J. Bonjour, R. Revellin","doi":"10.1109/TCAPT.2009.2027427","DOIUrl":"https://doi.org/10.1109/TCAPT.2009.2027427","url":null,"abstract":"Constructal analysis of tree-shaped microchannels for flow boiling in a disc-shaped body has been carried out to achieve an energy efficient design for chip cooling. n 0 channels touch the center and np channels touch the periphery. Three different complexities have been investigated: the radial flow pattern where n 0 = np; the one pairing level flow pattern where 2n 0 = np; and the two pairing level flow pattern where 4n 0 = np. The fluid is R-134 a evaporating at a temperature of 300 K. The fluid enters under a saturated state at the inlet and exits at the periphery. Throughout this paper, the constraints are the total volume of ducts V and the radius of the disc R. The degrees of freedom are the number of channels touching the center n 0, the number of peripheral channels np, and the mass flow rate. The disc, made of copper, is subjected to a heat flux on both its faces. Heat conduction has been simulated in the disc in the radial and angular directions combined with the boiling heat transfer coefficients and the pressure drops along the channels. The temperature field has been calculated and it can be observed that the highest temperature is located where the distance between two microchannels is the largest (most often at the periphery). For characterizing successive diameter ratios for complex structures, Murray's law is shown to be the best solution when using the homogeneous model for calculating the pressure drops. As a first conclusion, we can say that increasing the number of channels decreases the thermal resistance, whatever the complexity is. It is shown that the use of a radial structure with 2n 0 central channels is more efficient than a one pairing level design with n 0 central channels. Deeper analysis leads to different conclusions. For low pumping power, the radial flow pattern presents the lowest thermal resistance. For medium pumping power, one pairing level design shows the lowest pumping power. For higher pumping power, the design with two pairing levels exhibits the best solution. Finally, complexity is not necessarily the best solution.","PeriodicalId":55013,"journal":{"name":"IEEE Transactions on Components and Packaging Technologies","volume":"33 1","pages":"115-126"},"PeriodicalIF":0.0,"publicationDate":"2010-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TCAPT.2009.2027427","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62519396","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}