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Zastosowanie klejów anizotropowych w postaci folii w technologii flip chip oraz montażu paneli wyświetlaczy ciekłokrystalicznych

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Koncepcja przewodnictwa jednokierunkowego znana jest już od kilkudziesięciu lat, bowiem już na początku lat 60. ubiegłego wieku takie firmy, jak IBM, 3 M oraz Chomerics opatentowały anizotropowe warstwy przewodzące. Ale dopiero w latach 90. nastąpił gwałtowny wzrost zainteresowania tymi klejami. Anizotropowe kleje przewodzące są obecnie szeroko stosowane w wielu technologiach [1-4], gdzie wy[...]

Problemy montażu struktur SiC stosowanych w elektronice wysokich temperatur i dużych mocy

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W ostatnich latach dokonał się duży postęp w badaniach nad materiałami półprzewodnikowymi o szerokiej przerwie energii zabronionej. Z półprzewodnikowych materiałów szerokopasmowych takich jak: SiC, GaN, GaAs, AlN, BN i diament, węglik krzemu jest materiałem najbardziej obiecującym oraz najszerzej badanym i najintensywniej rozwijanym. Efektem tych badań jest coraz większa liczba opracowywanyc[...]

Design and realization of a microfluidic capillary sensor based on a silicon structure and disposable optrodes


  During the last years microfluidic sensors that use optical capillaries have gained an increasing importance due to their new applications as diagnostic tool in biotechnology, medicine and in environmental sciences. This was possible because the capillary enables multiparametric sensing [1-7] contrary to the classical optical fiber sensors [8], which find applications in physical measurements such as pressure and also magnetic field [9]. In this paper the improvements in the design of microfluidic sensors that use local heating in optical capillaries as a base of multiparametric diagnostics is presented [4]. The application of local heating opened interesting new possibilities for the sensors, that do not use any chemical sensitive layers or reagents, while raising specific issues relating to their construction, materials and technology [5]. The mentioned sensors can be used for in situ diagnostic in medicine and veterinary and as biofuel usability testers [10-12].The proposed microfluidic capillary sensor consists of a stabilized-intensity light source unit, a testing head with replaceable optical capillary, a heater and a detection unit. The optical capillary performs the functions of a liquid sample holder and at the same time of a multiparametric sensing element. The sensor operates in a multiparametric sensing mode, monitoring, registering and processing the indirect information such as the index of refraction, the boiling point, the vapour pressure, the heat capacity, the heat of fusion, the viscosity, the surface tension of the liquid and turbidity changes in a thermally forced measuring cycle. The measuring cycle is initiated by applying local heating to the sample [5]. The measuring cycle is controlled indirectly by changes in optical signals and temperatures [10]. The raw optical data are processed by an optoelectronic ci[...]

Mechanical and thermal properties of SiC - ceramics substrate interface


  Silicon carbide created new possibilities for high power and high temperature electronics due to its unusual physical properties, which are not attainable in conventional silicon semiconductor material. It has been demonstrated that SiC based power devices are able to operate at temperatures as high as 450°C [1, 2]. To realize the high temperature functions of SiC power devices, the development of high temperature packaging technologies becomes more and more important. Packaging technologies play main role in high power and high temperature electronics since they have an essential effect for the reliability of SiC power devices [8, 9]. One of the main problems of high power package is die bonding technology, which ought to assure not only mechanically reliable connection between SiC die and substrate, but also good electrical conductivity and high thermal conductivity. The latter feature is especially critical for power devices because it allows for effective heat transfer from power chip to the package. State-of-the-art technologies for interconnecting Si power devices involve attaching one terminal of the semiconductor die to a heat-sinking substrate with solder alloy or with an electrically conductive adhesive, while the other terminals are bonded by aluminum or gold wires as well as flip chip technology. Such interconnection technologies have several limitations in high-temperature operation because solder alloys/conductive adhesives usually have low melting/degradation temperatures. By changing substrate material is possible to increase heat dissipation. So, the package with DBC substrate is very good solution for high power application, since such package significantly improves heat dissipation and therefore is widely used in high power SiC modules. Investigations of new techniques are necessary for high temperature and high power SiC devices. Taking into account mentioned above requirements, only a few of the known die[...]

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