{"title":"Numerical Approach to Characterization of Thermally Conductive Adhesives","authors":"T. Falat, A. Wymyslowski, J. Kolbe","doi":"10.1109/ESIME.2006.1643972","DOIUrl":"https://doi.org/10.1109/ESIME.2006.1643972","url":null,"abstract":"Thermally conductive adhesives are one of the major concerns of the contemporary micro-electronics. They are especially important in application where the effective heat dissipation is the key factor for reliability issues. Currently there is a lot of ongoing research in order to improve the basic thermal property of adhesives, which is mainly heat conductance. According to the literature data the heat conductance can vary from 0.1 up to 60 W/m·K. It depends on the filler material and its content and configuration but also on thermo-mechanical properties of matrix. Numerical simulation becomes nowadays an inevitable tool for rapid non-destructive and low-cost experiments. The basic problem of numerical experiments is accuracy. Nevertheless the error can be minimized by combining the numerical and traditional experiments. This can be achieved by means of partial validation of numerical results by traditional experiments or by precise and appropriate material properties measurement. In fact, the above approach was applied in current work in order to simulate the influence of curing temperature and time on the thermal conductance of polymers. Thermally conductive adhesives belong to polymer materials. In order to apply numerical simulation it is required to have an appropriate description of the thermal and mechanical behavior of polymers. Most often polymers are described by cure dependent or independent linear viscoelastic model [3, 5]. Having this model, which in fact can be measured experimentally, it is possible to simulate the stress and strain field caused by polymer curing and shrinkage phenomena and finally assess the thermal conductance accordingly.","PeriodicalId":436133,"journal":{"name":"Polytronic 2005 - 5th International Conference on Polymers and Adhesives in Microelectronics and Photonics","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114081339","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":"Organic Semiconductors Providing New Solutions for Future Medical Implants","authors":"M. Schwarz, J. Buddefeld, V. Ortmann","doi":"10.1109/POLYTR.2005.1596491","DOIUrl":"https://doi.org/10.1109/POLYTR.2005.1596491","url":null,"abstract":"Although implantable medical microsystems like painkillers, deep brain stimulators and the promising cochlear implants, have reached a high degree of reliability and usability for the patient, the implementation of neural stimulators with hundreds or thousands of microelectrodes still suffers by the interconnection problem between the electrode array and the electronic stimulator device. A mechanically flexible interconnection of all electrodes of a large 2D-electrode array to a monolithically integrated stimulator/recorder device is almost impossible, since the integrated circuit can only be attached using either bumps or bonds. In this contribution, the usage of organic semiconductors for the implementation of an addressable active stimulator cell is proposed to overcome these limitations. This stimulator electronic can be fabricated either with printable long chain organic semiconductors or, as described here, with short chain semiconductors (oligomers) like pentacene. The mechanical flexibility of arbitrarily sized and shaped 2D multicontact array is completely preserved, if this flexible semiconductor electronic is interlaced between the electrode rows and columns.","PeriodicalId":436133,"journal":{"name":"Polytronic 2005 - 5th International Conference on Polymers and Adhesives in Microelectronics and Photonics","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134495838","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":"Development of Aqueous Colloidal Dispersions of Ladder-Type Polymers for Applications in Organic Field Effect Transistors","authors":"D. Sainova, S. Janietz, A. Wedel","doi":"10.1109/POLYTR.2005.1596515","DOIUrl":"https://doi.org/10.1109/POLYTR.2005.1596515","url":null,"abstract":"The development of organic semiconductors is an important and challenging topic of the modern microelectronics since they can be applied as active layers in devices combining the advantages of easy processing, low weight, mechanical flexibility and ability of properties-tuning by structural modifications. A spectacular example for these attractive properties are the organic field effect transistors (OFETs) which are highly important components and recently have been a subject to a significant technological development. Particularly attractive candidates for OFET-applications are the semiconducting polymers due to their simple, low-cost solution processing, at low temperatures that enable large-area deposition on broad range of substrates. Typically, the reports of the semiconducting polymers, as of most organic materials, discuss unipolar charge transport. The result are devices, that can operate either in p- or n-channel regime, based on charge transport of holes or electrons, respectively. However the availability of both charge transport types is necessary for the realisation of numerous important logic elements, such as p-n junction structures, bipolar transistors and complementary circuits. The research attention so far has been oriented predominantly towards the p-type semiconducting polymers. As a result a significant progress has been marked with the achievement of field-effect mobilities of up to 0.05-0.1 cm2/V[unk]s as reported for the regioregular poly(3-hexylthiophene) (P3HT) [1]. The n-type semiconducting polymers remain, however, markedly less developed. The reasons are, probably, the lower environmental stability and the higher susceptibility of the negative charge carriers to the presence of defect and impurities [2,3].","PeriodicalId":436133,"journal":{"name":"Polytronic 2005 - 5th International Conference on Polymers and Adhesives in Microelectronics and Photonics","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125736799","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}
D. P. Webb, C. C. Hsu, D. Hutt, Neil Hopkinson, Paul P. Conway, P. Palmer
{"title":"Polymer Overmoulding for Microfluidic Device Packaging and System Integration","authors":"D. P. Webb, C. C. Hsu, D. Hutt, Neil Hopkinson, Paul P. Conway, P. Palmer","doi":"10.1109/POLYTR.2005.1596503","DOIUrl":"https://doi.org/10.1109/POLYTR.2005.1596503","url":null,"abstract":"Packaging of microfluidics receives relatively little academic attention, and most published work concerns the facilitation of prototyping rather than schemes suitable for volume production. A new packaging method for microfluidic devices is proposed, of polymer overmoulding to form a fluidic manifold integrated with the device in a single step. The anticipated advantages of the proposed method of packaging are ease of assembly and low part count, making it suitable for low cost, high volume manufacturing. The work reported here is an investigation into the fundamental materials and process issues determining the feasibility of the proposed packaging method.","PeriodicalId":436133,"journal":{"name":"Polytronic 2005 - 5th International Conference on Polymers and Adhesives in Microelectronics and Photonics","volume":"171 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130852113","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}
H. Nilsson, J. Sidén, T. Unander, T. Olsson, P. Jonsson, A. Koptioug, M. Gulliksson
{"title":"Characterization of moisture sensor based on printed Carbon-Zinc energy cell","authors":"H. Nilsson, J. Sidén, T. Unander, T. Olsson, P. Jonsson, A. Koptioug, M. Gulliksson","doi":"10.1109/POLYTR.2005.1596492","DOIUrl":"https://doi.org/10.1109/POLYTR.2005.1596492","url":null,"abstract":"In this work we present a simple printed moisture sensor fabricated using electronic inks on a multilayer paper structure. The sensor is based on a Carbon-Zinc type energy cell and provides power to a readout electronic circuit when activated by moisture. The sensors are based on a number of our filed patents according to which the sensor is used for both event detection and as a power source for the processing electronics. Typical applications are moisture and leakage detection in buildings, water pipe lines, smart packages and health care systems such as smart incontinence sensors. As the detector is triggered, it powers up an electronic circuit (polymer based or silicon based) that starts communication with the alarm server. In the simplest systems a sound or a light alarm is started to alert the user. In this work we present a characterization of some critical parameters of the sensor such as power driving capability, linearity, internal memory effects and saturation. In addition, we examine a specific application, when sensor is used as defrosting alarm for surveillance of frozen articles during transport.","PeriodicalId":436133,"journal":{"name":"Polytronic 2005 - 5th International Conference on Polymers and Adhesives in Microelectronics and Photonics","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115974650","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":"Reliability aspects of electronics packaging technology using conductive adhesives","authors":"J. Liu, X. Lu, Liqiang Cao","doi":"10.1109/POLYTR.2005.1596527","DOIUrl":"https://doi.org/10.1109/POLYTR.2005.1596527","url":null,"abstract":"Conductive adhesive technology for electronics packaging and interconnect application has significantly been developed during the last decades. It is time to make a summary of what has been done in this field. The present paper reviews the technology development, especially from the reliability point of view. It is pointed that conductive adhesives are now widely used in many applications and the reliability data and models have been developed to a large extent for conductive adhesives in various applications.","PeriodicalId":436133,"journal":{"name":"Polytronic 2005 - 5th International Conference on Polymers and Adhesives in Microelectronics and Photonics","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121423282","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}
S. Ganesan, Geunwoo Kim, Ji Wu, M. Pecht, J. Felba
{"title":"Lead-free Assembly Defects in Plastic Ball Grid Array Packages","authors":"S. Ganesan, Geunwoo Kim, Ji Wu, M. Pecht, J. Felba","doi":"10.1109/POLYTR.2005.1596523","DOIUrl":"https://doi.org/10.1109/POLYTR.2005.1596523","url":null,"abstract":"Printed circuit boards were assembled at Jabil's San Jose facility using their qualified surface mount assembly processes. The assembly involved lead-free plastic ball grid array (PBGA) packages (256 I/O) soldered to FR4 and polyimide printed circuit boards. The maximum peak lead-free reflow temperature measured at a PBGA location was 246°C. After the lead-free reflow, the assemblies exhibited solder joint defects. The three defect modes were bridges, oversized solder joints, and insufficient solder joints; in some cases these all occurred within a single PBGA. This was not expected because the PBGAs were rated as moisture sensitivity level 3 (MSL 3) and the floor life restrictions were followed as per JEDEC 020C. This paper discusses the details of the defect phenomenon and the failure analysis, and also proposes the failure mechanism based on modeling and materials characterization data. Based on this study, recommendations are provided to prevent the occurrence of the assembly defects.","PeriodicalId":436133,"journal":{"name":"Polytronic 2005 - 5th International Conference on Polymers and Adhesives in Microelectronics and Photonics","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114635774","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}
H. Qi, S. Ganesan, Ji Wu, M. Pecht, P. Matkowski, J. Felba
{"title":"Effects of Printed Circuit Board Materials on Lead-free Interconnect Durability","authors":"H. Qi, S. Ganesan, Ji Wu, M. Pecht, P. Matkowski, J. Felba","doi":"10.1109/POLYTR.2005.1596504","DOIUrl":"https://doi.org/10.1109/POLYTR.2005.1596504","url":null,"abstract":"This study investigates the effects of printed circuit board (PCB) material on interconnect durability of lead free assemblies. The assemblies involve soldering various packages (array and peripheral) on to FR4, high glass transition temperature (Tg) FR4 and Polyimide (PI) printed circuit boards using Sn3Ag0.5Cu solder alloy. The glass transition temperature of these materials ranges from 130°C to 230°C. Thermomechanical properties, such as elastic modulus and thermal expansion coefficients, of the board materials vary considerably. These properties have a direct impact on the interconnect durability. In this paper, thermomechanical properties are experimentally determined and used for solder joint durability simulation. Two kinds of environmental loadings are simulated: temperature cycling and random vibration loading. The results show that PI board provides a better solder joint durability than FR4 and high TgFR4 under temperature cycling conditions. PI assembly has better durability than FR4 assembly under random vibration. The paper also presents the effect of temperature on the vibration response of the FR4 printed circuit board assemblies. The understanding of these changes can contribute to the study on interconnect durability under combined temperature cycling and vibration loading conditions.","PeriodicalId":436133,"journal":{"name":"Polytronic 2005 - 5th International Conference on Polymers and Adhesives in Microelectronics and Photonics","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133667038","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}
V. Baranov, V. Emelyanov, A. F. Kerentsev, D. Anufriev
{"title":"Selection criteria of press-materials and packaging conditions for power electron devices","authors":"V. Baranov, V. Emelyanov, A. F. Kerentsev, D. Anufriev","doi":"10.1109/POLYTR.2005.1596506","DOIUrl":"https://doi.org/10.1109/POLYTR.2005.1596506","url":null,"abstract":"Some design and technological restrictions of using known press-materials and packaging methods within package technology of power electron devices in the epoxy molded housings of ISOWATT-218 type have been examined. The results of experimental research of the device hermetic condition after their testing at high temperatures and humidity have been described. It is shown that a value of the housing thermal resistance for a certain press-material depends on process conditions, in particular depends on a velocity of the press-material injection into a form through founding channels. It has been discovered that the bigger diaphragm diameter (leading to increasing the velocity of the press-material injection into all parts of a press-form) leads to increase of the value of RT. Dependencies have a nonlinear character. The level of RTvalue depends on a press-material type. The conditions of packaging process with RTvalues of 2,5 - 3 °C / W have been founded for the press-materials MG-40F and EME 596. Decrease of an anti-adhesive grease that contains in the Russian press-material of MEP-5T type as well as the press-tablets prior heating exclusion leads to better quality of the plastic housing process formation.","PeriodicalId":436133,"journal":{"name":"Polytronic 2005 - 5th International Conference on Polymers and Adhesives in Microelectronics and Photonics","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114764084","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":"High Surface Planarity Die Bonding of Large Optical Chips","authors":"U. Kunzelmann, M. Wagner, H. Schenk, H. Lakner","doi":"10.1109/POLYTR.2005.1596499","DOIUrl":"https://doi.org/10.1109/POLYTR.2005.1596499","url":null,"abstract":"Analog Spatial Light Modulators (ASLM) are highly specialised MOEMS devices, which, in our case, are used as programmable mask in extremely high-resolution DUV mask writing systems. Resolution, precision, contrast and optical uniformity of the mask patterns produced by this new type of mask writers depend on the local and global planarity as well as on the optical contrast of the ASLM devices [1]. Definition, measurement and calculation of the global flatness (GF) of the active area of one-mega pixel ASLM devices, developed and fabricated at the Fraunhofer IPMS in Dresden, is described and applied for the investigations of parameters influencing the chip planarity. Parameters of an adhesive chip bonding technique have been varied and optimised with respect to improved GF. In particular, the influence of the die bonding layers printed on the die attach was investigated. Additionally, an approach based on ultraprecision micro-milling of a sacrificial layer deposited on the die attaches to improve its planarity and thus the GF of the die-bonded chip has been successfully performed.","PeriodicalId":436133,"journal":{"name":"Polytronic 2005 - 5th International Conference on Polymers and Adhesives in Microelectronics and Photonics","volume":"292 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133400223","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}