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Electronic Packaging Technology, 2005 6th International Conference on

Date Aug. 30 2005-Sept. 2 2005

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Displaying Results 1 - 25 of 148
  • Conference committee

    Publication Year: 2005 , Page(s): 1 - 4
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  • Real time stress monitoring in reflow solder: Cu thin films in Si(111)

    Publication Year: 2005 , Page(s): 269 - 272
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    Substrate curvature method (SCM) is a versatile optical stress measuring method which owns a lot of merits: realtime, rapid, nondestructive, easily operating. A film stress measuring apparatus by SCM was developed, and stresses in Ag/Cu multilayer thin films and reflow solder on Cu thin films in Si(111) prepared by RF magnetron sputtering were detected. The stress-temperature behavior was studied. The stresses in Ag/Cu multilayer thin films were different due to different temperature. The stresses in reflow solder on Cu thin films in Si(111) were different due to the generation of excessive amounts of intermetallic compound. The results identify that the interfacial reaction kinetics has effect on wetting dynamics in evidence. View full abstract»

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  • Solder Joint Reliability of Sn-Ag-Cu BGA and Sn-Pb Solder Paste

    Publication Year: 2005 , Page(s): 1 - 6
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (381 KB) |  | HTML iconHTML  

    In the transition to lead-free, components suppliers need carry the product of lead-free and lead components. This could cause the extensive logistic problems in manufacturing. Therefore, it is necessary to study the solder joint character of Sn-Ag-Cu BGA and Sn-Pb solder paste. In this study, the results of solder joint shape and reliability evaluations of PBGA (plastic ball grid array) lead-free package assembled to PCBs (printed circuit boards) with eutectic Sn-Pb solder paste was presented. The lead-free package was assembled under various reflow profiles and PCB surface finish. The peak temperature of reflow soldering of 210, 225 and 235 degC with the soak profile was used. The PCB surface finish included HASL (hot air soldering level) and ENIG (electro-less Ni/immersion Au). The different types of solder joints, both as-reflowed and after reliability test were examined using optical microscope, transmission X-Ray. The reliability test of TTC (thermal torsion cycling) and ATC (accelerated thermal cycling) was used. Detailed failure analysis is also presented View full abstract»

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  • Improvements in Au wire bondability of rigid and flexible substrates using plasma cleaning

    Publication Year: 2005 , Page(s): 366 - 371
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (376 KB) |  | HTML iconHTML  

    Thermosonic Au wire bonding is the most widely used interconnection technology in the BGA packages. Compare with Au ball bonding, the lower wire loop and finer bond pitch of Au wedge bond makes its ideal for low profile and high I/O applications, which is the subject of the current study. As bond pad surface cleanliness, substrate materials and wire bonding process parameters play a critical role on the yield of wire bonding, this study compare Au wedge wire bondability of rigid FR-4 and flexible polyimide (PI) substrate and examine the bonding improvements using plasma cleaning by the concept of process windows. Process windows demonstrate the bondability of the substrates at a combinations of varies bonding conditions, such as bonding temperature, bond power and with and without subjected to plasma cleaning. The plasma cleaning condition is optimized based on the process windows. Results indicated that a low plasma cleaning power with a short cleaning time resulted in the widest process window. Significant improvements of bondability were noted after plasma treatment with a substantial reduction in minimum bonding temperature for both substrates. The process window for the flexible substrate was much wider than the rigid substrates in the bonding conditions tested. View full abstract»

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  • Fast characterization for moisture properties of moulding compounds: influence of temperature and humidity

    Publication Year: 2005 , Page(s): 185 - 190
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (440 KB) |  | HTML iconHTML  

    Moisture induced failure is a major problem in modern IC technology. When there is moisture present in the moulding compound before the chip is soldered to the printed circuit board, or gets another heat treatment, the moisture expands. With the stresses that are introduced by the expanding compound, the package can crack, causing the failure. If the moisture concentration or the gradient in a material exceeds a critical value, the package breaks in the assembly process or fail during its lifespan due to the moisture. To find this critical value the standard tests, such as the assessment of moisture sensitivity levels (MSL), are useful, because they have proven to simulate real life use. However, for each new moulding compound material, such standard tests are needed, which may take up to 3-6 months of time. It would be more efficient to select these materials in advance, if the moisture behavior is known. If the moisture concentration distribution could be predicted before the final product is made, the time needed to develop a new product can be shorter. At present, no proper methods are available for fast characterization of moisture properties of epoxy materials. Even more, the exact relationships of such properties with temperature and humidity conditions are not exactly known. This paper describes our research to find these relationships. To find the relationships there are a series of tests proposed with varying room humidity's or temperatures. With the results of these tests and by using a fitting algorithm, the saturation concentration and diffusion coefficient for the compound can be deducted. It also allows us to validate whether the numerical approximation to Fick's second law is accurate enough to describe the moisture distribution in epoxy materials. Based on the formulas, a set of tests can be defined for fast characterization of epoxy materials to enable efficient material selection that can be used in the early stages of product development. The present stage of research is to validate the formula's found describing the dependencies of the diffusion coefficient and saturation concentration on humidity and temperature. View full abstract»

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  • CVD diamond film sink for high power MCMs

    Publication Year: 2005 , Page(s): 113 - 116
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (320 KB) |  | HTML iconHTML  

    As electronic packages become more compact, run at faster speeds and dissipate more heat, package designers need more effective thermal management materials. CVD Diamond, because of its high thermal conductivity, low dielectric loss and its great mechanical strength, is an excellent material for three dimensional (3-D) multichip modules (MCMs) in the next generation compact, high speed computers and high power microwave components. In this paper, we have synthesized a large area free-standing diamond films and substrates, and polished diamond substrates, which make MCMs diamond film sink becomes a reality. View full abstract»

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  • Effects of the electric field on Ni-induced crystallization in field-aided lateral crystallization process

    Publication Year: 2005 , Page(s): 166 - 170
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    As a crystallization process, the field-aided lateral crystallization (FALC) technique has some outstanding advantages, such as high crystallization rate and low temperature. In this study, an electric field was directly applied between source and drain areas of H shape patterns using the Mo-W interconnecting layer. The effects of the current density and the electrical field strength on the crystallization behavior were investigated. Such crystallization behaviors are attributed to the coexisting effects of electromigration and potential gradient. In addition, the dependence of the degree of crystallization on the current density was studied and the microstructure crystallized by FALC was compared with the microstructure crystallized by metal induced lateral crystallization (MILC) process. View full abstract»

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  • An application of MCM technology

    Publication Year: 2005 , Page(s): 117 - 120
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    With the emphasis on compactness in consumer electronic products, it is essential for electronic engineers to implement integrated systems. In this paper, an approach based on MCM technology, which implemented six discrete chips arranged in a single-package, is presented. This approach improved the integration of electronic system and met the demand of compactness in consumer electronic products. Among these discrete chips, two high-speed operational amplifiers with two chips of digital function were mounted on silicon substrate by using the silicon-on-silicon MCM technology, and the cheaper 3 μm metal gate CMOS technology was chosen to fabricate the silicon substrate. The Zeni EDA layout tool was used to design metal lines on the silicon substrate for interconnections between chips. Because the clock frequency of this system is above 100MHz, it is necessary to consider that the wire bonds, the package leads, the pins and the traces on silicon substrate can create signal-integrity problems, which prevent products from working correctly. The Agilent ADS momentum tool was used to simulate S-parameters of high frequency signal lines in silicon substrate, and the distance between the adjacent signals is optimized to minimize the coupling. Besides the design for interconnects, the heat transfer design of MCM package is also important. By using the Autotherm tool of Mentor Graphics' PCB Boardstation products, the thermal distribution of this system was analyzed, and the result indicated that if the other two high power chips were also arranged on the silicon substrate, the whole system was destroyed. Therefore, they were directly mounted on the copper lead frame, which is useful for heat transfer. The practical application implies that multiple bare dice implemented in different technology can be packaged into a standard IC package and works well. View full abstract»

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  • Parametric cost estimating: a practical independent method of estimating the manufacturing cost of chips to modules in the Peoples Republic of China

    Publication Year: 2005 , Page(s): 336 - 337
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    The cost estimating discipline is making rapid progress in the Peoples Republic of China. Parametric cost estimating tools, including a microcircuit parametric estimating model, have been introduced to the major large system developers in China. The parametric cost estimating process not only estimates product cost but also provides an effective program cost management tool used for design to cost trade studies. This paper introduces the parametric cost estimating method and explores the parametric process when applied to an advanced microcircuit packaging (LTCC) in a high volume, relatively low cost application used in a rugged environment. The PRICE Systems Microcircuit (PRICE M) parametric cost estimating model is presented along with its fundamental cost drivers and factors. An independent parametric estimate for a low temperature cofired ceramic (LTCC) microcircuit module is presented. The required estimating parameters and the resulting estimate is described along with a technical walk-thru using the independent parametric estimate of the 24 GHz short range radar sensor for automotive applications. The independent cost analysis estimate is based upon a microcircuit developed in a joint project of IMST GmbH (Germany) with DuPont Microcircuit Materials (a detailed presentation of the microcircuit project is described in the IMAPS Advancing Microelectronics March/April 2005 publication). The packaged chips and all components along with the LTCC substrate cost and assembly and test costs of the assembled module is estimated and presented. The entire estimate uses P.R. China financial factors. View full abstract»

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  • Flexible Silicon Microneedles Array for Micro Fluid Transfer

    Publication Year: 2005 , Page(s): 1 - 5
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    This paper reports on a new method of using silicon micro needle in bio-medical application. The hollow micro needle array have been designed and fabricated from single crystal silicon for transdermal delivery. The machined micro needles are shank height of 150mum with 250mum center-to-center spacing. The needle size, density and shape are controlled by independent processing steps. Packaging technology incorporates a micro needles array affixed to a polymeric adhesive base. The maximal adhesive patch size is 2 cm2. Flow rate test is proved that the polymeric base construction is important to function of micro needles array. Glucose solution tests show that surface tension is the dominant force to affect the characters of flow in micro needles channel View full abstract»

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  • Plasma considerations prior to wire bonding in advanced packaging

    Publication Year: 2005 , Page(s): 207 - 210
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (240 KB) |  | HTML iconHTML  

    Today's packaging engineers are faced with many challenges, including cost-saving strategies, yield-enhancing process steps, and damage-free preparation of intricate, small geometry devices such as multi-chip modules, stacked packages and hybrids. In order to ensure high device reliability and minimize manufacturing costs, a well-prepared surface for wire bonding plays a very important role in successful advanced packaging since it can significantly improve the quality and reliability of the bond. Gas plasma technology can be used to clean pads prior to wire bonding to improve bond strengths and yields. It is a powerful, efficient resource for surface preparation that can dramatically improve the manufacturability, reliability, and yield of advanced packages. In this paper, the types of plasma technologies and consideration for their use prior to wire bonding are discussed, and experimental results are reviewed. Examples specific to epoxy bleed-out contamination and considerations regarding substrate material and device characteristics are also addressed. View full abstract»

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  • Study on Life Distributions of the Elements Based on Rough Function Theory

    Publication Year: 2005 , Page(s): 1 - 4
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (334 KB) |  | HTML iconHTML  

    In view of the facts that complexity of life distributions of the parts, classical exponential distributions can't truthfully and profoundly portray it due to inconsideration depreciation behavior impacts in process of the elements life, therefore, under many situations, the acquired results do not accord with objectivity. However, once deviating from the assumption of the exponential distributions, quantitative analysis of the stochastic life will face difficulties. Therefore, in accordance with the characteristics of phase-type(PH) distributions of its approaching all distributions in nature, the paper applies the rough function concept to construct the PH distribution function sets called the upper approaching and the lower approaching sets, the upper approaching function set is those smallest distribution functions whose lives are bigger than practical life, the lower approaching distribution function set is those largest distribution functions whose lives are smaller than practical life, the boundary between them is a measurable domain of practical life distributions. The section is created in [0,+infin) by PH distribution function classes, after a larger number of the elements lives are tested and processed, the life distributions of the tested elements only rely on its location in the boundary. Obviously, the lower approaching function sets are those PH distributions that all tested elements lives are bigger than their lives, and the upper approaching function sets are those PH distributions that all tested elements lives are lower than their lives, the remained PH distribution classes can more accurately approach practical life of the elements. The paper forecasts the life distributions of the elements by using of mixed Erlang distribution, a sort of PH distribution function classes, research results show that the method is simple and flexible, and is an instruction idea for evaluation of life or life distributions of the elements, and relatively more accur- - ate than conventional ways based on exponential distributions, and more robust View full abstract»

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  • Simulation study on precision vibration reduction system for working stage of lithography

    Publication Year: 2005 , Page(s): 325 - 329
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (552 KB) |  | HTML iconHTML  

    The paper aims at ensuring accurately its static state and dynamic state to a relative stabilization level and reducing the vibrating amplitude of the simulated working table during the exposure processing of a lithography. According to the step motion and synchronous scanning motion of the lithography and some features of the earth vibration, the paper designs the precision vibration reduction of the simulated working stage of the lithography and chooses STACIS-2000 vibration reduction equipments as the active vibration reduction equipments. Meanwhile the paper establishes the virtual simulation model of lithography by virtue of the ADAMS software. Using passive and active control method analysis, the typical impulse working response of the simulated work stage. The results indicate that only using passive vibration reduction method cannot meet the working requirements of the lithography and the active vibration reduction method must be used and the design in this paper can meet the requirements. View full abstract»

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  • Nano-silver paste with low roasting temperature

    Publication Year: 2005 , Page(s): 226 - 228
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (320 KB) |  | HTML iconHTML  

    A kind of new silver paste with silver content about 50wt%, nano-silver paste, significantly different with normal silver paste in roasting temperature, was prepared using nano-silver powder, ethanol, n-butyl alcohol, n-hexyl alcohol and low polymer fibre. The nano-silver paste shows weight loss and volatilization with different levels on thermogravimetric (TG) analyzing curve. Field emission scanning electron microscope (FESEM) analysis indicates when roasting temperature is controlled at 200°C, the surface of finished silver film has already been compact and smooth. And finished silver film has stronger adhesive with ceramic and mental substrates, while the adhesive is poor with slippery glass. The minimal square resistor of obtained silver film can reach 7.8mΩ/□. View full abstract»

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  • Synthesis of undercoat with high temperature and humidity resistance for resistor

    Publication Year: 2005 , Page(s): 245 - 248
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    Epoxy resin undercoat, with high temperature and humidity resistance, for resistor was prepared by curing of acid anhydride and accelerating of glycol with proper nano-SiO2 added at 80°C. The properties of undercoat prepared were characterized by electrical tests, infrared spectra (IR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The results showed more compact and steady inter-crosslinked network structure was formed in the modified epoxy resins undercoat with nano-SiO2 added, which leaded to the performance of modified epoxy resin undercoat improved greatly. The undercoat with nano-SiO2 2.68wt%, kept for six months at room temperature without flocculating and aggregating, is of good stability. The varying ratio of resistance with such undercoat painted is less than 1% after high temperature and humidity resistance test. In this work, an attempt has been made to prepare undercoat, with high temperature and humidity resistance, for resistor by modifying epoxy resin using nano-SiO2. View full abstract»

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  • Thermal Fatigue Failure Analysis of Copper Interconnects under Alternating Currents

    Publication Year: 2005 , Page(s): 1 - 4
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (562 KB) |  | HTML iconHTML  

    In this paper, we present transmission electron microscopy (TEM) investigations of a potential failure mode for Cu lines subjected to alternating thermal loads. Wide Cu lines with 200 nm thickness were produced on a Si/SiO2/SiNx wafer by a series of conventional microfabrication steps. Alternating currents (AC) with a frequency of 100 Hz was then applied to the Cu lines and produced temperature cycles with a range of 190degC due to Joule heating. The cyclic temperature change gave rise to a cyclic strain in the Cu line due to the difference in the thermal expansion coefficient between the metal line and the wafer. The thermally-induced mechanical cyclic loading leads to the formation of severe damage in the Cu lines, such as thinning along the twins and wrinkles in the grain. Eventually the AC loading leads to local melting and electrical failure of the Cu line. TEM investigations revealed that constrained diffusional creep and the interaction of dislocations with twins and other interfaces play an important role in the development of damage. The results for Cu lines tested under thermal fatigue conditions are compared with the microstructure and damage morphology of films tested under pure mechanical fatigue and the important differences and the corresponding damage mechanisms are discussed View full abstract»

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  • Structural Similarity as a Method to Reduce Qualification Tests

    Publication Year: 2005 , Page(s): 1 - 6
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    To efficiently select qualification and reliability monitoring programs, structural similarity rules for integrated circuit designs, wafer fabrication processes and/or package designs are currently used by the industry. By following the package structural similarity rules, the numbers of reliability qualification tests may be greatly reduced. However, when looking at the present rules it is clear that they are not reliably defined. For instance, geometrical parameters such as die-to-pad ratio are not quantitatively included and it seems that linear relationships are assumed. Besides that, these rules are mainly deducted from experience and industrial trial and error results, not from reliability physics. Driven by the present development trends of microelectronics (miniaturization, integration, cost reduction, etc) it is urgently needed to develop 'structural similarity rules' based on reliability physics (physics of failures), to meet the industrial development trends. In this study, we have used simulation-based optimization techniques to deduct such structural similarity rules. Parametric 3D non-linear FE models are used to explore the responses of the complete BGA family for both the thermo-mechanical and moisture-diffusion responses as function of six parameters among which the die-to-pad ratio and the body size. In this way, structural similarity rules are deduced which can be used to shorten design cycles. Even more, by using the accurate 3D nonlinear reliability prediction models, an Excel-based tool is created for package designers. By using this tool, the number of reliability qualification tests can be reduced. More importantly, possible failure mechanisms can be (better) understood and predicted View full abstract»

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  • Characterization of Interface Strength as function of Temperature and Moisture Conditions

    Publication Year: 2005 , Page(s): 1 - 6
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (330 KB) |  | HTML iconHTML  

    Since moisture sensitivity level (MSL) tests are part of the international reliability qualification standards, all the microelectronics components/products have to pass these specifications. Therefore, it is important to be able to efficiently and accurately characterize and predict the moisture related material and interface behavior in the real manufacturing, processing, testing and application conditions. The success of interfacial fracture mechanics approach to analyze moisture-induced failures in IC packaging strongly depend on accurate characterization of the critical adhesion strength, GC . However, its measurement is complicated by the fact that adhesion depends not only on moisture concentration, C, but also temperature, T, and mode mixity, Psi. This paper described our research to develop a reliable methodology for interface toughness evaluation as function of temperature, humidity and mode mixity. Our methodology includes using the four-point bending test and shaft-loaded-blister method. Dedicated specimens consisting of various types of moulding compounds bonded onto leadframe are manufactured. Besides temperature, moisture content and mode mixity effects, also the influences of surface treatment (leadframe oxidation and contamination) and production process on the interface fracture toughness are evaluated. Multi-physics-based numerical methods are used to transfer the experimental critical loads to an interface strength parameter. These analysis covers mechanical, moisture diffusion, vapor pressure, hygro-swelling and CTE-mismatch modeling. To test and improve the methodology, various effects are evaluated, such as crack-length dependency, material properties, specimen-width, displacement-rate of the upper support/shaft, etc. The results of the proposed methodology indicate, as expected, a change in interface toughness by mode mixity, moisture content and temperature. It is found that GC decreases with increasing moisture content- - and temperature. The presence of moisture at the given interface is observed as the important factor in the reduction of interfacial strength (Gt 20 - 45%). Furthermore, G C; increases by a factor 3-4 when the mode mixity shifts towards mode II View full abstract»

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  • Prediction of Delamination in Micro-electronic Packages

    Publication Year: 2005 , Page(s): 1 - 6
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (419 KB) |  | HTML iconHTML  

    At present, a lot of delamination related reliability problems are observed in the micro-electronic industry. Examples are: die-lift; downbond stitch breaks associated with diepad delamination; passivation cracks related to interface delamination between chip and moulding compound. These reliability problems are driven by the mismatch between the different material properties, such as CTE, hygro-swelling, vapor pressure induced expansion, and degradation of the interfacial strength due to moisture absorption. The associated negative business consequence is significant. Clearly, the driving mechanisms of these delamination related problems should be explored before possible solutions can be found, such as expensive design changes and/or expensive material types to limit the delamination. This paper highlights our results to find the driving mechanisms for delamination-related reliability problems in micro-electronic packages using state-of-the-art virtual prototyping and/or qualification techniques. The numerical predictions are combined with novel interfacial adhesion test techniques able to measure the interfacial strength as functions of both temperature and moisture. As a typical example, delamination in the exposed pad package family is taken as a carrier. Novel numerical techniques are developed to predict the occurrence of interfacial delamination as function of manufacturing and testing conditions in micro-electronic packages. These techniques are improvements of well-known methods, such as virtual crack closure, J-integral, cohesive zone, and area release. The area release method does not require any presupposed position of any initial crack. Instead, at any desired positions within the specimen, an area energy release value is calculated which basically results from releasing an area (having a defined dimension) around each point in the specimen. Several reliable non-linear finite element models are developed to predict the moisture diffusion, deformation, - - stress, and interfacial energy history as functions of processes, temperature and moisture. Thus the effect of hygro-swelling, vapor pressure, interfacial degradation, and thermal expansion on delamination failures is predicted. Finally, by combining the models with simulation based optimization methods, design guidelines are derived for reducing reliability problems in microelectronic packages where the results provide us generic insight in the mechanisms of delamination-related problems View full abstract»

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  • Detecting and Analyzing Wafer Bump Voids with X-Ray Inspection

    Publication Year: 2005 , Page(s): 1 - 3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (199 KB) |  | HTML iconHTML  

    Many different inspection systems are available to manufacturers of electronic components. But new inspection challenges are pushing - and in many cases exceeding - the limits of conventional inspection tools, such as wafer probes and automated optical inspection systems. A more capable alternative is X-ray technology, which can penetrate substrate materials to expose hidden features in electronic assemblies. Equipped with this cutting-edge tool for detecting material flaws and component defects, manufacturers can improve product quality and increase customer satisfaction, while also reducing costs and increasing manufacturing efficiency. This paper discusses X-ray inspection systems and their importance in failure analysis and process control of electronic components. Besides describing basic X-ray technology, the paper looks at a number of recent developments in X-ray systems and shows how these developments improve the inspection of TCs, PCBs, packages, and wafer bumps View full abstract»

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  • Study of the effects of molding pressure on the warpage of HVQFN packages

    Publication Year: 2005 , Page(s): 338 - 343
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (624 KB) |  | HTML iconHTML  

    In electronic packaging, molding compounds are frequently used for encapsulation. During manufacturing processes, the combined chemical shrinkage and thermal expansion often result into undesirable product warpage. Molding temperature, molding pressure and time are three major parameters affecting the curing quality of molding materials. Investigation of the effects of molding pressure on the warpage of HVQFN (head-sink very-thin quad flat non-lead) packages is important for minimizing the warpage and residual stresses and the optimal design of the products. In previous work a cure-dependent viscoelastic constitutive model gave a good prediction of the process induced stresses and warpage in HVQFN packages with different curing temperatures and degree of cure. In this paper, the effect of molding pressure on warpage of HVQFN packages is studied with the aim of verifying and modifying the previously proposed model. The typical map-chips with 65% silica particle-filled epoxy resin are manufactured under 5 molding pressure levels from 1.8 to 12.3 MPa. The curvature measurements are performed for the packages after demolding and post curing respectively. The viscoelastic tensile relaxation modulus of molding materials is obtained by using dynamic mechanical analysis (DMA). The characterization of evolution of equilibrium moduli is analyzed for verification and future modification of the model. The experimental results show that the molding pressure has a significant effect on the warpage after molding as well as after post curing of HVQFN packages. The curvatures of HVQFN packages at both lower (1.8MPa) and higher molding pressures (12.27MPa) are about 45% less than the average max curvature at 3.6 ∼ 8.66MPa. The molding pressure has influences on the glassy Young's modulus but has no effects on the rubbery modulus and relaxation time of the package materials. View full abstract»

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  • Effect of Die Bonding on MEMS Characteristics: Cell Library Study

    Publication Year: 2005 , Page(s): 1 - 5
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (378 KB) |  | HTML iconHTML  

    Thermal mismatch induced by the die bonding structure will have a great effect on the reliability and performance of MEMS devices. A cell library method is introduced here as an alternative against conventional FEM simulation to simplify the package-device co-design and the parametric study of MEMS components. Cells of package substrate, anchor and micro-beam are first modeled individually and then integrated together on their boundary conditions to study the concerned response. Effects of die bonding on the pull-in voltage of a doubly supported micro-beam are predicted using this method and the results are in good agreement with FEM calculations. This study indicates the importance of package-device co-design and the need for the development of MEMS own standard package solutions aiming at stress miniaturization and modeling simplification View full abstract»

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  • The lithography with low-COO and high-performance for advanced packaging

    Publication Year: 2005 , Page(s): 351 - 354
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (240 KB) |  | HTML iconHTML  

    Lithography technology for advanced packaging is quite different from that for other applications. Because the applications of WLP and wafer bumping often require lithography system to define bumping-array patterns across the wafer or to create redistribution a layers or integrated passive devices with resist lagers of thick (20-100μm) and feature sizes large (2-150μm). At the same time, the package process is extremely cost-sensitive and requires nearly perfect yield with very thick photoresist and photopolymer layers as presented in J. Hermanowski (2004). In this paper, we would like to introduce a lithography system with low-COO and high performance, it can meet and allow the requirements of advanced packaging. View full abstract»

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  • Analysis of Heat Dissipation Performance of CVD Diamond Film's Sink for 3D-MCM

    Publication Year: 2005 , Page(s): 1 - 3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (259 KB) |  | HTML iconHTML  

    3D-MCM may play a important role in microelectronics in next century, a key problem must be solved: how to remove internal heat to exterior effectively in practical use . This work describes the use of CVD-diamond on stacked 3D-MCM thermal management, the symmetry of the model was utilized, a three dimensional model of only 1/4 section of the model was built and numerical simulation based on FEA was performed. A comparison was made between the calculated temperature distribution using CVD-Diamond and that using other materials . View full abstract»

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  • Study on Angle Deviation for Coupling Loss in Fiber Collimator Packaging

    Publication Year: 2005 , Page(s): 1 - 4
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    Angle deviation of optical components in fiber collimator packaging is theoretically analyzed, and resolution expression of the relationship between angle deviation of components and coupling loss of collimator is deduced due to transmission equation of GRIN (gradient index lens). Then the economical tolerance of collimator assembly, which provides the theoretical foundation to establish MOEMS mathematic model of packing collimator and realize industrialized production, is confirmed View full abstract»

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