14:02 Dec 9, 2001 |
English to French translations [Non-PRO] Tech/Engineering | ||||
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| Selected response from: michnick Local time: 14:40 | |||
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5 | see explication below | |||
5 | see explication below |
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2 | 5-1000 ohms/µm2 |
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see explication below Explanation: See, e.g. at http://www.ece.gatech.edu/research/labs/vc/theory/sheetRes.h... In diffused semiconductor layers, resistivity is a strong function of depth. For circuit design, it is often convenient to work with a parameter called the "sheet resistance" (Rs). Consider the resistance (R) of the rectangular block of uniformly doped material. In this sample the resistance is given by: R = Rho * L / A where Rho is the resistivity of the sample, and L and A are its length and cross-sectional area, respectively. If W is the width of the sample and t is its thickness (i.e. - A = Wt), then the resistance can be written: R = (Rho/t) (L/W) = Rs (L/W) where Rs = Rho/t is the sheet resistance of a layer of this material. Strictly speaking, the unit for sheet resistance is the ohm (since L/W is unitless). To avoid confusion between R and Rs, however, sheet resistance is specified in unit of "ohms per square." The L/W ratio can be thought of as the number of unit squares (of any size) of material in the resistor. Alors, il ne s'agit pas ni de m2, ni de mm2 – il s'agit tout simplement du nombre des carres dont la dimension ne joue aucun role :) HTH |
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see explication below Explanation: See, e.g. at http://www.ece.gatech.edu/research/labs/vc/theory/sheetRes.h... In diffused semiconductor layers, resistivity is a strong function of depth. For circuit design, it is often convenient to work with a parameter called the "sheet resistance" (Rs). Consider the resistance (R) of the rectangular block of uniformly doped material. In this sample the resistance is given by: R = Rho * L / A where Rho is the resistivity of the sample, and L and A are its length and cross-sectional area, respectively. If W is the width of the sample and t is its thickness (i.e. - A = Wt), then the resistance can be written: R = (Rho/t) (L/W) = Rs (L/W) where Rs = Rho/t is the sheet resistance of a layer of this material. Strictly speaking, the unit for sheet resistance is the ohm (since L/W is unitless). To avoid confusion between R and Rs, however, sheet resistance is specified in unit of "ohms per square." The L/W ratio can be thought of as the number of unit squares (of any size) of material in the resistor. Alors, il ne s'agit pas ni de m2, ni de mm2 – il s'agit tout simplement du nombre des carres dont la dimension ne joue aucun role :) HTH |
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5-1000 ohms/µm2 Explanation: Les courants qui circulent dans un circuit intégré sont excessivement faibles, de l'ordre du microampère en moyenne par transistor pour un processeur de dernière génération : 100 Watts dissipés pour 50 millions de transistors donnent 0,5 µA par transistor en moyenne sous un alimentation de 3V. Mille portes alimentées ensemble et à travers un jonction de 1 mm2 présentant une résistance de 1000 ohms/mm2 provoqueront une chute de tension inacceptable(d'autant que mon calcul fait référence à une moyenne) puisque le courant total de 0,5 mA équivaudrait à une chute de tension de 0,5 V. Il semble donc que vous ayez raison de penser que 1000 ohms soit trop élevé. J'airai tendance à penser qu'il s'agit donc de micromètres carrés (µm2). Le symbole µ est peut être mal reproduit dans votre texte. Les gravures actuelles en sont à une largeur de motif de 18 µm. On retombe donc sur des chiffres plus que vraisemblables. Je n'ai pas trouvé d'info sur le net pour vous aider d'avantage. Il ne s'agit que de considérations théoriques HTH 25 ans d'instrumentation |
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