By Topic

Components and Packaging Technologies, IEEE Transactions on

Issue 2 • Date June 2005

Filter Results

Displaying Results 1 - 25 of 36
  • [Front cover]

    Page(s): c1
    Save to Project icon | Request Permissions | PDF file iconPDF (64 KB)  
    Freely Available from IEEE
  • IEEE Transactions on Components and Packaging Technologies publication information

    Page(s): c2
    Save to Project icon | Request Permissions | PDF file iconPDF (40 KB)  
    Freely Available from IEEE
  • Table of contents

    Page(s): 177 - 178
    Save to Project icon | Request Permissions | PDF file iconPDF (49 KB)  
    Freely Available from IEEE
  • Full text access may be available. Click article title to sign in or learn about subscription options.
  • Four decades of research on thermal contact, gap, and joint resistance in microelectronics

    Page(s): 182 - 206
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1192 KB) |  | HTML iconHTML  

    The Keynote Paper reviews and highlights over 40 years of research on solutions for steady-state and transient thermal constriction and spreading resistances, and thermomechanical models for contact, gap and joint resistances of joints formed by conforming rough surfaces, nonconforming smooth surfaces, and nonconforming rough surfaces. Microgap and macrogap thermal resistance and conductance models are reviewed, and important relations and correlation equations are presented. Contact microhardness, determined by Vickers indenters, are correlated and incorporated into the contact model for conforming rough surfaces. Microhardness parameters are correlated with Brinell hardness values. Elastoplastic contact models for joints formed by smooth sphere-smooth flat and conforming rough surfaces are presented. A simple thermomechanical model for microgaps occupied by oil, grease, grease filled with solid particles, and phase change materials such as paraffins is reviewed, and good agreement with recently published data is noted. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Hierarchical thermal analysis of large IC modules

    Page(s): 207 - 217
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1152 KB)  

    This paper presents a new approach to hierarchical thermal modeling using libraries of parametrized sub-models. It is demonstrated how to efficiently create thermal sub-models based on a parametrized model reduction technique. These sub-models are then used for fast simulation of complex parts using a hierarchical modeling building methodology that nests sub-models within sub-models. As an example of such a model parametrized thermal sub-models of a GaAs power cell, an integrated GaAs microwave power amplifier and an InP optical modulator are generated. A complete module is then built by attaching these sub-models to detailed models in a hierarchical manner, creating a thermal model of the entire system. This methodology allows a quick thermal analysis to be performed of very large systems. The thermal sub-models are small in size, boundary condition independent, have very short simulation times, and predict with high accuracy (better then 2% error) all internal temperatures. Finally, the optical modulator model is used as example of the computational efficiency of the methodology. Although an absolute speed-up is difficult to define two cases were provided with gains of around 30 to 40 times calculated. System memory requirements were also reduced by a factor of three. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On one-dimensional analysis of thermoelectric modules (TEMs)

    Page(s): 218 - 229
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (656 KB) |  | HTML iconHTML  

    A novel framework for the one-dimensional analysis of a thermoelectric module (TEM) in which controlled and uncontrolled sides rather than cold and hot sides of it are defined is introduced. Next, heat conduction in a TEM is considered within this framework. Then, the operating modes of a TEM (cooling, generation, etc.) are defined and a means to compute the operating mode from a minimal set of operating parameters is provided. Refrigeration mode is considered in depth to illustrate the application of the analysis framework. Finally, the analysis is extended to TEMs subjected to boundary conditions of the third kind. Novel aspects of the analysis are indicated in the Conclusions. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Rheology based modeling and design of particle laden polymeric thermal interface materials

    Page(s): 230 - 237
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (368 KB) |  | HTML iconHTML  

    Most of the research on particle laden polymeric (PLP) thermal interface materials (TIM) have been primarily focused ob understanding the thermal conductivity of these types of TIMs. For thermal design reduction of the thermal resistance is the end goal. Thermal resistance is not only dependent on the thermal conductivity, but also on the bond line thickness (BLT) of these TIMs. This paper introduces a rheology based model for the prediction of the BLT of these TIMs from very low to very high pressures. BLT depends on the yield stress of the particle laden polymer and the applied pressure. The model is based on the concept of finite size scaling of physical properties of particle laden systems at very thin length scale due to percolation phenomenon in these materials. This paper shows that the yield stress of the PLP increases with decreasing thickness of the TIM and therefore it is size dependent. The BLT model combined with the thermal conductivity model can be used for modeling the thermal resistance of these TIMs for factors such as particle volume faction, substrate/die size, pressure and particle diameter. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Thermal design and optimization of natural convection polymer pin fin heat sinks

    Page(s): 238 - 246
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1096 KB) |  | HTML iconHTML  

    The design and optimization methodology of a thermally conductive polyphenylene sulphide (PPS) polymer staggered pin fin heat sink, for an advanced natural convection cooled microprocessor application, are described using existing analytical equations. The geometric dependence of heat dissipation and the relationships between the pin fin height, pin diameter, horizontal spacing, and pin fin density for a fixed base area and excess temperature are discussed. Experimental results of a pin finned thermally conductive PPS heat sink in natural convection indicate substantially high thermal performance. Numerical results substantiate analytical modeling results for heat sinks within the Aihara et al. fin density range. The cooling rates and coefficient of thermal performance, COPT, that relates cooling capability to the energy invested in the formation of the heat sink, has been determined for such heat sinks and compared with conventional aluminum heat sinks. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Optimization of pin-fin heat sinks using entropy generation minimization

    Page(s): 247 - 254
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (560 KB)  

    In this study, an entropy generation minimization, EGM, technique is applied as a unique measure to study the thermodynamic losses caused by heat transfer and pressure drop in cylindrical pin-fin heat sinks. The use of EGM allows the combined effect of thermal resistance and pressure drop to be assessed through the simultaneous interaction with the heat sink. A general expression for the entropy generation rate is obtained by considering the whole heat sink as a control volume and applying the conservation equations for mass and energy with the entropy balance. Analytical/empirical correlations for heat transfer coefficients and friction factors are used in the optimization model, where the characteristic length is used as the diameter of the pin and reference velocity used in Reynolds number and pressure drop is based on the minimum free area available for the fluid flow. Both in-line and staggered arrangements are studied and their relative performance is compared on the basis of equal overall volume of heat sinks. It is shown that all relevant design parameters for pin-fin heat sinks, including geometric parameters, material properties and flow conditions can be simultaneously optimized. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Fins, fans, and form: volumetric limits to air-side heatsink performance

    Page(s): 255 - 262
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1400 KB)  

    In design of high performance heatsinks, it is vital to understand how the primary constraints of volumetric footprint and hydraulic operating point limit maximum thermal performance. This paper provides a framework to establish a priori maximum attainable levels of air-side cooling performance for a given class of fin geometry over a basis of continuously varied footprint and hydraulic constraints. A model of packaging volume required for air moving devices to deliver flow and pressure is developed. It is shown how single fin thermal model results may be extrapolated to multiple fan-heatsink combinations within an open design space. A method to identify fin-fan combinations to achieve maximum system volumetric conductance levels is presented. The methodology is extendable to other volumetrically constrained heat exchanger problems. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Ebullition characteristics of an isolated surface microstructure for immersion cooled heat sinks

    Page(s): 263 - 271
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1392 KB)  

    An understanding of the fundamentals of the boiling mechanism is essential if phase-change liquid immersion cooling is to emerge as a cooling option for the next generation of data servers and other high performance electronics. The present work is an experimental study on the effect of cavity mouth size on the nucleation characteristics of a single isolated micro-pyramidal reentrant cavity. Cavity mouth size has long been known to be a primary variable determining the ebullition characteristics of microscopic structures present on a pool boiling heat sink surface. Isolated pyramidal shaped cavities with square mouth sizes of 7, 19, and 25μm etched in polished silicon using an anisotropic etch were evaluated in this study. Serpentine thin film heaters (6.9mm × 6.9mm) deposited on a Borofloat glass substrate and anodically bonded to the silicon cavity section served as heat sources. All experiments were conducted at atmospheric pressure in dielectric fluids, HFE-7100 and FC-72, popular in thermal management applications. High speed photography (up to 600frames/s) was used to record and quantify the effect of heat flux on bubble departure frequency and departure diameter under subcooled and saturated conditions. The bubble departure diameter increased with an increase in the cavity mouth size. Frequency and bubble departure size, both decreased with increased subcooling. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Fluid flow and heat transfer in liquid cooled foam heat sinks for electronic packages

    Page(s): 272 - 280
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1136 KB) |  | HTML iconHTML  

    In this paper, the fluid flow and heat transfer of liquid cooled foam heat sinks (FHSs) were experimentally investigated. Eight Open-celled copper foam materials with two pore densities of 60 and 100 PPI (pores per inch) and four porosities varying from 0.6 to 0.9 were bonded onto copper base plates to form the FHSs, which were then assembled on flip chip BGA packages (FBGAs) with a common thermal grease as the thermal interface material. A liquid cooling test loop was established to obtain the pressure drops and overall thermal resistances. For the four 60 PPI FHSs, the one with the lowest porosity of 0.6 is found to possess the lowest thermal resistance level with the largest pressure drop. Generally the FHSs with 100 PPI had slightly lower thermal resistances at the same flowrates but much larger pressure drops than those with 60 PPI. In the overall performance assessment, the thermal resistances of the FHSs are plotted against the pressure drop and the pump power, together with a microchannel heat sink of similar unit cell scale and structural dimensions. The thermal resistances of the FHS with a porosity of 0.8 and pore density of 60 PPI were identified to be the lowest among all the FHSs, which outperformed the microchannel heat sink at large pressure drop and pump power. The reduced heat sink thermal resistance and Nusselt numbers for the present FHSs and microchannel heat sink are also presented and compared with the FHS reported in the literature. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A novel hybrid heat sink using phase change materials for transient thermal management of electronics

    Page(s): 281 - 289
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (656 KB) |  | HTML iconHTML  

    A hybrid heat sink concept which combines passive and active cooling approaches is proposed. The hybrid heat sink is essentially a plate fin heat sink with the tip immersed in a phase change material (PCM). The exposed area of the fins dissipates heat during periods when high convective cooling is available. When the air cooling is reduced, the heat is absorbed by the PCM. The governing conservation equations are solved using a finite-volume method on orthogonal, rectangular grids. An enthalpy method is used for modeling the melting/re-solidification phenomena. Results from the analysis elucidate the thermal performance of these hybrid heat sinks. The improved performance of the hybrid heat sink compared to a finned heat sink (without a PCM) under identical conditions, is quantified. In order to reduce the computational time and aid in preliminary design, a one-dimensional fin equation is formulated which accounts for the simultaneous convective heat transfer from the finned surface and melting of the PCM at the tip. The influence of the location, amount, and type of PCM, as well as the fin thickness on the thermal performance of the hybrid heat sink is investigated. Simple guidelines are developed for preliminary design of these heat sinks. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Miniature loop heat pipes-a promising means for cooling electronics

    Page(s): 290 - 296
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (688 KB) |  | HTML iconHTML  

    Loop heat pipes (LHPs) are highly efficient heat-transfer devices, which have considerable advantages over conventional heat pipes. Currently, miniature LHPs (MLHPs) with masses ranging from 10-20 g and ammonia and water as working fluids have been developed and tested. The MLHPs are capable of transferring heat loads of 100-200 W for distances up to 300 mm in the temperature range 50-100°C at any orientation in 1-g conditions. The thermal resistance for these conditions are in the range from 0.1 to 0.2 K/W. The devices possess mechanical flexibility and are adaptable to different conditions of location and operation. Such characteristics of MLHPs open numerous prospects for use in cooling systems of electronics and computer systems. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Mechanical, thermal, and electrical analysis of a compliant interconnect

    Page(s): 297 - 302
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1520 KB)  

    Ball grid array (BGA) package styles use solder balls as electrical interconnects between packages and application boards. Solder balls are rigid and tend to fracture under thermal fatigue and/or shock loading. Metalized polymer spheres (MPS) offer a more compliant interconnect, compared to solder balls, thereby increasing the thermal cycling fatigue life. A reduction in thermal and electrical performance may be expected for MPS interconnects as a result of its higher thermal and electrical resistances. A 5% and an 8% increase in MPS thermal resistance was measured for a carrier array ball grid array (CABGA) package and a plastic ball grid array (PBGA) package, respectively, compared to eutectic solder balls. However, this small reduction was offset by large gains in the solder joint life. A 1.6 times increase in the mean thermal fatigue life was measured for a CABGA using MPS interconnects compared to eutectic solder balls. A first-order model showed that eutectic solder balls provide greater process margins, compared to MPS interconnects, due to the ball collapse during reflow. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Study of assembly processes for liquid crystal on silicon (LCoS) microdisplays

    Page(s): 303 - 310
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (640 KB) |  | HTML iconHTML  

    This paper involves the development of two critical assembly processes for liquid crystal on silicon (LCoS) microdisplays. The processes investigated include the lamination of cover glass on silicon and a LC filling process. For the lamination process, a tool and process were designed and developed with the objective to attach the cover glass on a silicon die and achieve a cell gap of 3-μm between them. The gap was achieved and verified with various measurement techniques. The lamination process involved the deposition of an adhesive ring and subsequently squeezing the two parallel plates until the desired cell gap was achieved. An analytical model was developed to estimate the time required to achieve a 3-μm cell gap by applying different pressures on the cover glass. The analytical model proved to be a guideline in developing the lamination process. The second process in the assembly is filling the cavity between the cover glass and silicon with LC material. For LC filling, a tool was designed and process was developed. The process works on the principle of flow of fluid in a capillary. The flow rate was enhanced by applying a vacuum to the cavity. An analytical model was developed to estimate the time needed to fill the 3-μm wide cavity. Fill time is a function of gap width between glass and silicon, pressure applied within the cavity, cavity length and the viscosity of the LC material. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Mitigation of connector damage during disengaging DC loads using polymeric arc suppressor

    Page(s): 311 - 318
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1416 KB) |  | HTML iconHTML  

    Although connectors are generally not designed to disconnect electrical loads under power, in some circumstances they are mated and unmated under load. For instance, during repairs, diagnostic procedures, or when blown fuses are replaced under short circuit conditions. At dc system voltage levels significantly higher than the minimum arc voltage of metals such hot-disconnections may impact the reliability of the connection, the electrical distribution system, and automotive safety. Gassing polymers mounted onto connector terminals may reduce the damage resulting from disconnections under dc loads, and therefore enable connector designs with occasionally (forward running) arcing terminals. The authors discuss the effects of different types of gassing polymers on arc extinction and connector damage of standard automotive connectors. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Mitigation and analysis of arc faults in automotive DC networks

    Page(s): 319 - 326
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1424 KB) |  | HTML iconHTML  

    The introduction of system voltages higher than 24 VDC in vehicles, forces considerable component and system changes regarding reliability and electrical safety. In the instance of an arc fault, e.g., when a wire is cut, pinched, chafed or breaks under load, or an arc is drawn between disconnecting terminals, the resulting fault current may be significantly lower than the trip current of common protection devices such as fuses or circuit breakers. In these cases, the fault is cleared late (depending on the time/current characteristics) or, in some cases, not at all. The authors discuss different types of arc faults and introduce approaches to deal with them. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Adhesion improvement of thermoplastic isotropically conductive adhesive

    Page(s): 327 - 336
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1376 KB) |  | HTML iconHTML  

    Generally, isotropically conductive adhesive formulations include epoxy resin as the polymeric matrix. Although epoxy has superior adhesion capability, its drawbacks include the tendency to absorb moisture and lack of reworkability (thermosetting polymer). In this study, a thermoplastic polymer with low moisture absorption (0.28 wt%), called polyarylene ether (PAE2), is used in isotropically conductive adhesive (ICA) formulation. Previous research work by Lu et al. showed that the moisture absorbed into epoxy caused galvanic corrosion, which result in the formation of metal oxide . By using a polymer with low moisture absorption, the amount of water present in ICA will be small, and the corrosion rate and formation of metal oxide can be reduced. However, previous measurements of contact resistance stability of PAE2-based ICA showed that they are not stable on all surface finishes. It was determined that for thermoplastic-based ICA, poor adhesion was the main mechanism for unstable contact resistance. Two methods of adhesion improvement will be evaluated in this work. The first is to use coupling agents and the second is to blend the thermoplastic with epoxy. Both methods showed promise in improving the contact resistance stability of polyarylene ether based ICA. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The evaluation of copper migration during the die attach curing and second wire bonding process

    Page(s): 337 - 344
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1336 KB) |  | HTML iconHTML  

    Copper migration on the silver plated surface of the lead-frames with various heat treatments was evaluated by X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and atomic force microscopy (AFM) methodologies. Copper migration may introduce copper oxidation and result in the wedge bonding failures due to the nonstick on lead (NSOL) phenomenon. Experiments were performed on the two kinds of TQFP leadframes with the stamped and etched manufacturing processes subjected to various heat treatments and bonding conditions to understand the underlying physics. TEM and AFM provided the additional insight of the grain structure and surface roughness of silver. XPS results showed that the etched leadframe was relatively better one that less copper oxide was detected on the silver surface after annealing process. However, more copper was observed to diffuse onto the silver surface after annealing in the stamped leadframe. In comparison between the stamped and etched lead-frames, the silver plated layer in later one is more efficient in blocking copper diffusion-either surface or bulk. Finally a full factorial design of experiment (DOE) with wedge bond pull strength as response was performed to verify the results of XPS, TEM, and AFM. The evaluations based on XPS, TEM, and AFM analyzes can really help to improve the yield of the wedge bonding process and optimize the IC manufacturing process window. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Determination of thermal compact model via evolutionary genetic optimization method

    Page(s): 345 - 352
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (392 KB) |  | HTML iconHTML  

    Genetic Algorithms (GA) are adaptive search algorithms based on the theory of natural selection and survival of the fittest. In this study, GA was used to derive a thermal compact model of a micro lead frame package. The GA derived model was then used to compute the junction temperature (Tj) of the package for various boundary conditions. The results obtained were checked against simulation results of a detailed thermal model and were found to be within ±1.5% of error. Computational time taken by the detailed finite element model required approximately 4 min whereas the GA derived model took less than 35 s to generate the Tj of the package. Further, the study shows the feasibility and potential of applying GA as a powerful tool for optimization. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Thin layer acoustic image interpretation and metrology for microelectronics using a broadband model

    Page(s): 353 - 365
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (528 KB) |  | HTML iconHTML  

    A broadband model is proposed to describe the nature of ultrasonic pulses in multilayered systems with a sub-wavelength thickness layer. Experimental results are presented to illustrate how delaminations and cracks with foreign material or moisture ingress can appear to be well-bonded and why acoustic images of interfaces with thin layers can sometimes give erroneous indications of the bond state. Applications of this model for delamination analysis of a geometrically complex package are demonstrated. The model can not only predict ultrasonic pulses in the time and frequency domain accurately (the forward problem), but can also provide a theoretical framework for solving the inverse problem, namely, measurement of the thickness and material properties of sub-wavelength thick coatings and layers. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Flow time measurements for underfills in flip-chip packaging

    Page(s): 366 - 370
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (384 KB) |  | HTML iconHTML  

    Flow time is a key material property for underfill materials in flip-chip applications. In this paper, we will discuss how to use flow time testing for underfill flow evaluation and material screening. The flow time of several underfills was measured at elevated temperatures using test pieces made from glass microscope slides. The material properties impacting underfill flow, such as viscosity, contact angle, and surface tension, were also experimentally measured and used to calculate estimated flow times using the Washburn equation. Empirical and calculated flow times were compared. The effects of channel width and flow distance on flow time were also studied. Additionally, the effect of a tilted stage on flow time, epoxy tongue, and void formation was evaluated. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Open Forum Editorial

    Page(s): 371
    Save to Project icon | Request Permissions | PDF file iconPDF (148 KB)  
    Freely Available from IEEE

Aims & Scope

IEEE Transactions on Components and Packaging Technologies publishes research and applications articles on the modeling, building blocks, technical infrastructure, and analysis underpinning electronic, photonic, MEMS and sensor packaging.

 

This Transaction ceased production in 2010. The current publication is titled IEEE Transactions on Components, Packaging, and Manufacturing Technology.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Koneru Ramakrishna
Freescale Semiconductor, Inc.