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Polymers and Adhesives in Microelectronics and Photonics, 2001. First International IEEE Conference on

Date 21-24 Oct. 2001

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  • First International IEEE Conference on Polymers and Adhesives in Microelectronics and Photonics. Incorporating POLY, PEP & Adhesives in Electronics. Proceedings (Cat. No.01TH8592)

    Publication Year: 2001
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  • Conference author index

    Publication Year: 2001 , Page(s): xi - xiii
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    Freely Available from IEEE
  • Will polymer electronics change the electronics industry?

    Publication Year: 2001 , Page(s): 1 - 8
    Cited by:  Papers (4)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (795 KB) |  | HTML iconHTML  

    Polymer electronics forms a new and very promising technological area, which may pave the way to many new applications and products. The use of electroluminescent semiconductive polymers for emissive displays is already rather mature. At present, the first commercial products are ready to be launched. Polymer light-emitting diode based displays indeed will be the first polymer electronics products to reach the market. It is expected that the thin emissive displays, which can be realized with this new technology, will command an important place in the display market. The use of polymer transistors in ICs and in transponders, and as pixel switches for displays is still in its infancy. Applications have been demonstrated in a research environment, but significant effort is still required to address production issues and to demonstrate business opportunities. The current state of affairs is comparable with that at the beginning of the rise of the silicon-based IC industry, some 40 years ago. The application of polymers for low-cost electronic products, like labels and barcodes and for electronic paper, will lead to a family of very interesting new products, which will definitely change the electronics industry. New options for polymer electronics, e.g. their possible application for photovoltaics (e.g., in organic solar cells) and as sensors, and for solid storage, are just beginning to be explored. The answer to the question proposed in the title must therefore be yes. View full abstract»

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  • Semiconductor packaging technology for mobile phones in Japan

    Publication Year: 2001 , Page(s): 9 - 19
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    In semiconductor packaging technology for mobile phones, rapid development in materials, structures, manufacturing methods, and design architecture are making it possible to create phones with higher density, lighter weight, and better performance than ever before. Innovations in polymer materials are largely responsible for such improvements. Future-generation mobile phones are required to keep up with wireless communications on higher-speed transmission. Due to this requirement, the mobile phone industry expects engineers to develop new polymer materials capable of keeping circuitry free from electrical noise even under high-speed operation. View full abstract»

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  • OLED matrix displays: technology and fundamentals

    Publication Year: 2001 , Page(s): 20 - 28
    Cited by:  Papers (7)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (779 KB) |  | HTML iconHTML  

    For more than a decade, considerable effort has been put into the development of light emitting devices based on evaporated layers of organic semiconductors. To date, the properties of matrix displays consisting of organic light emitting diodes (OLEDs) basically meet automotive and consumer product requirements. OLED matrix displays offer high contrast, wide viewing angle and a broad temperature range at low power consumption. In contrast to polymer devices, OLEDs are processed in ultrahigh vacuum systems. The organic source materials are sublimated from effusion cells. Due to the sensitivity of organic thin films, device structuring by conventional etching techniques is not feasible and alternative structuring techniques were developed. Electrical current in organic devices is limited by the low conductivity of organic semiconductors and by energy barriers at the metal-organic semiconductor interface. Photoelectric measurements facilitate the determination of barrier height differences between various electrode set-ups. Further insights into the energy band alignment at organic heterointerfaces are gained by ultraviolet photoelectron spectroscopy (UPS). In addition to widely employed electrical (I-V, C-V) and optical (PI) measurements, thermally stimulated current (TSC) and luminescence (TSL) allow the characterization and a more detailed understanding of carrier traps and charge transport in organic devices. Energy transfer in a doped OLED emitting layer can be investigated by time-resolved photoluminescence measurements. View full abstract»

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  • New fabrication technology of polymer/metal lamination and its application in electronic packaging

    Publication Year: 2001 , Page(s): 29 - 34
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (507 KB) |  | HTML iconHTML  

    A new fabrication technology for lamination between LCP (liquid crystalline polymer)and copper is presented. The method is based on a surface activation process prior to the clad bonding process. The fabrication conditions and the microstructure of the bonded interface as well as the mechanism of the bonding are discussed with respect to various experimental results. Some practical applications of the new clad materials in electronic packaging are also presented. View full abstract»

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  • Micro dispensing of adhesives and other polymers

    Publication Year: 2001 , Page(s): 35 - 39
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (445 KB) |  | HTML iconHTML  

    Due to the progress in miniaturization of electronic and optoelectronic devices, new processing methods are needed for micro dispensing of adhesives and other polymers. Applications are found in fields like joining, marking and coating. Here, micro dispensing is defined in volume ranges of 30-500 pl (/spl sim/30-500 ng). Not only small volumes but also precision and flexibility are in high demand. For a certain range of adhesives and other polymers used especially in optoelectronic devices, microdrop provides equipment for microdispensing. The basic technique is a spin-off from inkjet-technology and profits from the flexibility and precision of this technology due to the contactless drop ejection. Also, extremely aggressive organic solvents do not cause problems for the valve-free dispensers. This makes the microdrop technology very attractive for solved polymers as used for LEP (light emitting polymer) applications. Here, the actual applications and possibilities are illustrated and the current developments for improved processing strategies are described. There are some demands on the properties of such polymers usable for micro dispensing. These are explained and the limitations are discussed. View full abstract»

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  • Advanced micro-dispensing system for conductive adhesives

    Publication Year: 2001 , Page(s): 40 - 45
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (678 KB) |  | HTML iconHTML  

    As part of this paper, systems suitable for the micro-dispensing of conductive adhesives are presented and their advantages and disadvantages are also discussed. Additionally, cause-and-effect correlations of various influencing parameters are presented and analyzed, both for dispensing systems and for robotics. A further central theme is made up by the geometries of suitable needles for the precision dispensing of conductive adhesives. In closing, a new technique developed at the Fraunhofer IPA for the high-accuracy dispensing of conductive epoxy resins is presented. The most important part of the new system is a micro-pump system combined with pneumatic micro-valve actuators. View full abstract»

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  • Polymer materials for display technology

    Publication Year: 2001 , Page(s): 46 - 48
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    Polymer materials are well known in modern microelectronics. In the past, however, they have been used mainly for passive materials, substrate and encapsulating materials and adhesives. Special polymers with conjugated units have been employed as functional materials for the last decade. The first displays based on organic light-emitting diodes (OLEDs) have been on the market for a short time and the development of flexible OLEDs with a long lifetime is the proclaimed aim of many research institutes and companies. The Fraunhofer IAP is working on the development of new polymer materials and device technologies in this research area. View full abstract»

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  • Semiconductor nanoparticles: new building blocks for polymer-microelectronics?

    Publication Year: 2001 , Page(s): 49 - 53
    Cited by:  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (372 KB) |  | HTML iconHTML  

    The following paper describes the new possibilities for applications, resulting from the combination of luminescent semiconductor nanoparticles (so-called quantum dots) and conducting polymers. First the theory will be briefly introduced, then three examples will be described and discussed: quantum dot light-emitting diodes (QDLEDs), generally quantum dot/conducting polymer composites and, finally, quantum dot photoelectric devices. By these examples, the state of the art is described and future possibilities are shown. View full abstract»

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  • Reproducibility investigations and different experiments with a new type of electronically-conducting-polymer based bipotentiostatic uric acid sensor

    Publication Year: 2001 , Page(s): 54 - 59
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    Reproducibility investigations and different experiments with a new type of electronically-conducting-polymer based bipotentiostatic uric acid sensor have been made. The sensor was constructed by using dodecyl sulfate doped poly-N-methyl-pyrrole for enzyme immobilization. This polymer film can incorporate the enzyme in one step during its electropolymerisation. By the bipotentiostatic measuring method the two working electrodes (with and without the enzyme) are analogously prepared and polarized and the currents in the two circuits are measured parallel in time. The layout, which consists of 4 electrode surfaces (W1, W2, Ref, Counter) was prepared by thick film technology on sintered alumina ceramic substrates. The reproducibility of the characteristics using various electrode materials (Au, Pt), and the influence of the temperature or the current density of the polymerisation have been investigated. Different pretreatment of the working electrodes have been applied. Comparison of two type of uricase enzymes have been made. View full abstract»

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  • Self-assembling /spl pi/-conjugated oligothiophenes for nanoelectronics: from organized molecular wires to macrocyclic circuits

    Publication Year: 2001
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    Since conjugated oligomers and polymers can be considered as 'molecular wires' and building blocks for 'molecular' or 'nano-electronics', we will describe their self-assembling behaviour which was investigated by means of scanning tunneling microscopy (STM). Furthermore, the self-assembling properties of novel macrocycles are reported. 2D- and 3D-structural characterizations provide intriguing self-organization properties. View full abstract»

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  • Reliability studies of an isotropic electrically conductive adhesive

    Publication Year: 2001 , Page(s): 61 - 69
    Cited by:  Papers (1)
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    ICA reliability continues to be a source of concern for widespread practical implementations in commercial products. In addition, there is still much to be understood in the basic principles of how such materials function. This paper includes contributions in both areas, in further understanding of ICA size effects, in the interpretation of the beneficial effects of vacuum treatments before curing, with additional drop test data, and with critical comments on common electrical test techniques. View full abstract»

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  • PC 3000-the new generation of isotropic conductive adhesives

    Publication Year: 2001
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    Summary form only given. The use of conductive adhesives as a completion of soldering is becoming more and more important for mounting electronic components and bare dies on substrates. The new PC 3000, a thermosetting, single-component, solvent-free, silver-filled, isotropic conductive adhesive (ICA) is presented. Application examples for the automotive and telecommunication industries are shown. Advantages like outstanding thermal conductivity are demonstrated and some special aspects with regard to properties and processing are discussed. View full abstract»

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  • Electrical conduction of adhesive joints in microwave applications

    Publication Year: 2001 , Page(s): 71 - 78
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    The electrical conduction of adhesive joints is provided by the metal content, and high conductivity requires high metallic content. Isotropic electrically conductive adhesives are usually manufactured with filler concentration sufficiently greater than the percolation threshold to guarantee low resistance with allowance for manufacturing tolerances. However, we have found that it is not sufficient in the case of microwave applications since, due to the skin effect, only a thin layer of adhesive plays an important role in current conduction. Therefore, it is necessary to secure the proper arrangement of filler particles on the adhesive joint surface. In this work, instead of measuring adhesive joint conductivity, we have measured the quality factor of the resonant circuit, which was made as a stripline circuit, including the measured joints. It was found that quality factor did not increase if the blend of silver flakes and heavy silver (powder) was used as a filler. In meantime, in the same filler mixture, the adhesive conductivity has increased in the DC range, as expected. It means that not the filler volume content but eventual particle disorder on the joint surface is of the highest importance in the case of solder replacement with electrically conductive adhesives in microwave electronics. View full abstract»

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  • Non-migration conductive adhesives

    Publication Year: 2001 , Page(s): 79 - 83
    Cited by:  Papers (1)
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    Ag filled isotropic conductive adhesives (ICAs) have been investigated as promising alternatives to lead-containing solders in surface mount technology (SMT) applications. However, one serious concern is the electromigration of silver filled ICAs, especially when used in high density interconnection assembly. This paper investigates electromigration resistance of ICAs using Ag-Sn alloys as conductive fillers. It was found that electromigration resistance depends on Ag:Sn ratios and that Ag-Sn alloys containing 25/spl sim/75 mol% of Sn have excellent resistance. These new ICAs and conventional ICAs (as reference) were evaluated for SMT, using chip components with several kinds of terminations for their stability of contact resistance and adhesion strength during reliability tests. From the test results, it can be concluded that the new ICAs are suitable potential materials for SMT application. View full abstract»

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  • Printed polymer transistors

    Publication Year: 2001 , Page(s): 84 - 90
    Cited by:  Papers (3)  |  Patents (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (651 KB) |  | HTML iconHTML  

    Integrated plastic circuits (IPCs) based on organic field-effect transistors (OFETs) have many advantages. One potential is the use for commercial applications such as low cost ident-tags or electronic barcodes. In order to achieve low production cost, the transistors must be prepared by printing processes. In this paper, we present OFETs and organic inverters based on functional polymers with single layers applied by pad and screen printing. The pad printing technique is an efficient method for patterning the electrodes of an OFET. With this technique, dimensions of 20 /spl mu/m were reached. Source-drain and gate electrodes consisting of either polyaniline, carbon black conductive ink, gold, or silver filled ink were printed. With these structures, OFETs were assembled, in which poly(3-alkylthiophene) served as the semiconductor, and poly(4-hydroxystyrene) as the insulator. These polymers were deposited homogeneously by screen printing or spin coating. In addition, a gate dielectric for an OFET was also pad printed. A full organic inverter with all electrodes printed is introduced. As the production speed of the presented printing techniques has the ability to be scaled up, the potential for high volume printing of organic electronics is proven. View full abstract»

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  • Plastic electronics based on semiconducting polymers

    Publication Year: 2001 , Page(s): 91 - 94
    Cited by:  Papers (1)  |  Patents (25)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (449 KB) |  | HTML iconHTML  

    Plastic electronics are set to be one of the next applications of semiconducting polymers appearing on the market. The electronics are constructed from integrated plastic circuits (IPC) based on organic field effect transistors (OFETs). The aim of this technology is to create low cost electronics using inexpensive standard polymer technologies in combination with laser and/or printing technologies which allow mass production for low cost mass products like ident tags, electronic watermarks, smart cards, electronic labels. Although many improvements have been achieved during the last few years, numerous problems still must be solved. The authors present recent results for OFETs with conjugated polymers like polythiophenes as active semiconducting material. The performance of the OFETs strongly depends on the quality of the semiconducting layer, i.e. molecular ordering, homogeneity, purity and doping level. Several aspects of preparing OFETs with special emphasis on the effect of the properties of the semiconducting polymer on the transistor parameters are discussed. View full abstract»

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  • A new structuring technique for polymer integrated circuits

    Publication Year: 2001 , Page(s): 95 - 97
    Cited by:  Papers (1)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (328 KB) |  | HTML iconHTML  

    We present a new technique for structuring polymeric interconnects and drain/source contacts of organic field-effect transistors in polymer integrated circuits. Our method is based on the selective electrochemical polymerisation of conductive polymers (e.g. PEDOT) on electrodes partially covered with a patterned insulating layer and the subsequent transfer of the polymeric structure to a flexible plastic substrate. Lateral resolutions of 10 /spl mu/m have already been obtained. The process is simple, does not require costly techniques like photolithography or vacuum deposition and it has the prospect of being applicable in reel-to-reel industrial processes. View full abstract»

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  • Polymeric materials for adaptronic fibre modules

    Publication Year: 2001 , Page(s): 98 - 103
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    The scientific field of "Adaptronics" combines sensor and actuator effects with electronics. The components furnished with adaptronics shall sense relevant properties and shall adapt in an intelligent way-they shall "feel, think and act". For instance, one application is the active vibration compensation of dynamically stressed structures. The scope of the work to be presented is to manufacture sensor/actuator microsystems with a low stiffness and thickness in order to sustain the favourable properties of the lightweight material used. In so doing, various adhesives and casting materials play an indispensable part in the manufacturing processes. The micro manufacturing of such systems is an activity of the Fraunhofer-Institute IFAM. The approach chosen includes the utilisation of piezo electric fibres in the diameter range from 20 /spl mu/m-200 /spl mu/m. The fibre modules consist of many fibres being contacted by interdigitated electrodes made of electrically conductive adhesives. In addition, structural adhesives and casting polymers are used. View full abstract»

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  • Green polytronics

    Publication Year: 2001 , Page(s): 104 - 111
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    Due to the anticipated high economical relevance of polytronics (low cost, high volume, high innovation rates, short product life, exploding diversity of products), life-cycle engineering is required at an early stage of material and process development. The environmental effects of polytronics are highly variable depending as much on the stage of product life (material production, product assembly, use, and end of life) as on the type of the materials. Due to the expected widespread use of polymers in mobile products, an environmental assessment is necessary to get further criteria for the selection. The high complexity of life-cycle assessment using conventional methods is found to be exemplary for the production of epoxy resin, a versatile pre-product for many applications. Since ecological assessment is key for improvement and optimization, a simplified methodology for the regarded complex products and processes is essential. EE-Toolbox provides a screening method developed especially for electronic products, based on the material content. As polymer materials until now are only considered according to their content of certain additives, a new tool for environmental screening assessment of these materials is introduced. With regard to the need for CO/sub 2/ reduction and energy preservation, characteristic incineration values are used for rating. It is assumed that thermal pretreatment is a major disposal pathway, particularly for future mobile products. The environmental impact of polymer materials is expected to be much lower compared to that of heavy metals and their compounds. Thus, expectations are high for environmental benefits of polytronics, but further examinations are necessary. View full abstract»

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  • The study of self-alignment capability of electrically conductive adhesives (ECAs) using low melting point alloy for flip-chip application

    Publication Year: 2001 , Page(s): 112 - 118
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    A feasibility study of the self-alignment capability of electrically conductive adhesives (ECAs) for a flip-chip interconnection application was carried out. The effect of the low melting alloy (LMA) filler on the self-alignment capability of ECAs was investigated. The surface energy of the epoxy resin was studied in terms of the various additives and their loading level using a goniometer with a built-in environmental chamber. The curing profile of the epoxy resin and the melting point of the LMA filler were measured using a differential scanning calorimeter (DSC). The ECAs filled with the LMA over 85 wt% showed self-alignment during the heating process. However, when silver flakes were added to the ECA formulation, self-alignment did not take place. We concluded that the LMA filler depleted into the silver flakes can adversely affect the self-alignment of ECAs. The key parameters required for ECA self-alignment capability are presented. This paper discusses the feasibility of the application of ECA with self-alignment capability for flip-chip interconnection. Initial results from these series studies indicate that incorporation of the LMA into ECAs is an efficient way to make ECAs with self-alignment capability. View full abstract»

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  • The underfill processing technologies for flip chip packaging

    Publication Year: 2001 , Page(s): 119 - 123
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (439 KB) |  | HTML iconHTML  

    Flip chip technology has been developed for more than 30 years and is widely used in the assembly of high-performance devices that require good functionality on substrate space. Compared to traditional wire bonding interconnection, flip chip technology offers tremendous advantages such as eliminating wire bond connections, increasing input/output (I/O) density, and using less space on substrates. With the rapid growth in flip chip technology, the need for assembly services has been developed. The key challenge in flip chip technology development is to improve the reliability of flip chip assembly. To enhance reliability, underfill materials are applied to the gap between die and substrate to provide mechanical support as well as environmental protection to the assembly. Capillary flow underfill material is used to fill the gap and protect the flip chip bumps for better reliability performance for years, but it has the limitations of lower throughput, higher cost and storage. Transfer molded underfill was developed to replace liquid type underfill materials to provide a high productivity process, less expensive materials and reliable performance. This study compares capillary underfill and molded underfill processes. Suggestions for various flip chip package types and performance concerns are then provided. View full abstract»

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  • Improved reliability with underfilled area array packages

    Publication Year: 2001 , Page(s): 124 - 129
    Cited by:  Papers (1)
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    Flip chip in package is expected to become a major solution for area array packages such as BGA (ball grid array) and CSP (chip scale package), which will represent over 20% of all flip chip devices by 2005 on a global scale. Manufacturers of portable electronic components such as mobile phones, laptops, camcorders, pagers or portable organisers are already using these packages to continue the steady reduction in size and weight. With the trends towards smaller pitch, smaller solder ball height and larger die size, the use of underfill material becomes more important. In particular, wafer level CSPs fall into this category, because they are similar to the bare chip attachment approach. View full abstract»

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  • Advanced flip chip encapsulation: transfer molding process for simultaneous underfilling and postencapsulation

    Publication Year: 2001 , Page(s): 130 - 139
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1149 KB) |  | HTML iconHTML  

    The process development for four flip chip molding compounds was based on material characterization by DSC, DMA and TMA. It was shown that the materials tested do allow reliable flip chip molding. Materials properties concerning processability and reliability are promising. There is strong potential of the technology for the increasing market of flip chip packages as certain types of BGA's and, with further miniaturization, CSP's. As these packages incorporate typically single dies, the transfer mold process can be adapted without major changes to existing equipment. Even for future developments such as one chip flip chip SIP's using advanced IC thinning and assembly methods, the flip chip molding underfill process is a successful vision for reliable encapsulation. View full abstract»

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