Dielectric power dissipation

Equation 5 is the practical equation for computing power dissipation in materials and objects of uniform composition adequately described by the simple dielectric parameters. 

The dielectric permittivity as a function of frequency may show resonance behavior in the case of gas molecules as studied in microwave spectroscopy (25) or more likely relaxation phenomena in soUds associated with the dissipative processes of polarization of molecules, be they nonpolar, dipolar, etc. There are exceptional circumstances of ferromagnetic resonance, electron magnetic resonance, or nmr. In most microwave treatments, the power dissipation or absorption process is described phenomenologically by equation 5, whatever the detailed molecular processes. 

The minimum length l and width id of a resistor are calculated from the given resistance R, the sheet resistance R in ohms per square, dissipated power P, and permissible power dissipation per square inch P by use of the formulas u> = /(P R)/P R and l = u>R/R. The capacitance of film capacitors is given by C = 0.225D(W — 1 )A/t, where C is the capacitance in picofarads. D the dielectric constant. N the number of plates, A die area in square inches, and / the dielectric thickness in inches. 

The optimum characteristic impedance is dictated by a combination of factors. Interconnections with low characteristic impedance (<40 fl) cause high power dissipation and delay in driver circuits, increased switching noise, and reduced receiver noise tolerance (35). High characteristic impedance causes increased coupling noise and usually has higher loss. Generally, a characteristic impedance of 50-100 fl is optimal for most systems (35), and a ZQ of 50 fl has become standard for a variety of cables, connectors, and PWBs. For a polyimide dielectric with er = 3.5, a 50-fl stripline can be obtained with b = 50 xm, tv = 25 xm, and t = 5 xm. 

A disc capacitor of thickness 1 mm carries circular electrodes of diameter 1 cm. The real and imaginary parts of the relative permittivity of the dielectric are 3000 and 45 respectively. Calculate the capacitance and the power dissipated in the dielectric when a sinusoidal voltage of amplitude 50 V and frequency 1 MHz is applied to the capacitor. [Answer 245 mW]... 

It is instructive to consider important features of the design of high-power capacitors in some detail, particularly with regard to power dissipation. The average rate P at which heat is developed in a dielectric due to the dissipation of electrical energy is... 

In addition to the construction of a multilevel interconnect network, the semiconductor industry also improves the performance of IC chips by incorporating low-resistivity metal wiring such as copper and new dielectric materials with lower k constant (see Section 1.3.1 for details). The added benefit of using low-fc dielectric materials includes a reduction in the crosstalk [29-31] and power dissipation [29-33]. The key challenge for the implementation of low-fc materials is related to their intrinsic weak mechanical properties. Furthermore, in order to achieve a k value below 2.2, practically all materials are made with pores that exacerbate mechanical stability issue [29-33]. This is a particular concern for the CMP community as the operation invariably involves mechanical stress and shear force. In addition, practically all low-fc dielectric materials are hydrophobic in nature. Lfpon exposure to moisture or wetness, the dielectric constant tends to increase. Therefore, unlike silicon-dioxide-based dielectric, the effective k constant may change after CMP. To... 

From Equation (2.3), the RC delay is directly proportional to the dielectric constant of the ILD. By switching from oxide-based ILD to a low e, ILD material, significant gains may be obtained in decreasing the interconnect delay. In addition, lowering dielectric constant lowers cross talk due to capacitive coupling between adjacent metal lines and power dissipation which is given... 

The dissipation of microwave power by ceramics is a function of the material properties s and s, which are the real (storage) and imaginary (loss) parts of the dielectric constant, respectively. In addition to the frequency dependence of pabs [Eq. (la)], s and s are themselves functions of the microwave frequency, the ambient temperature, T, as well as material properties, including a number of microstructural and chemical variables. Thus, to emphasize the range of parameters that impact the local power dissipation, we define the following symbols M denotes the microstructural variables, especially volume fraction porosity (VFP), as well as the size, shape, and the distribution of size... 

The corona power dissipated in a gaseous gap in series with one or more dielectric barriers can be calculated from the expression (3, 4)... 

Capacitive interference, the signal delay caused by the permittivity of insulating layers, the minimum required interlayer dielectric thicknesses, and the power dissipation, can all be decreased by designing polymers with lower values of e. The synthesis of polymers which simultaneously have low values of and outstanding thermal and mechanical properties is therefore crucial for applications in the electronics industry. 

Calculate the power dissipated as a function of co for a Debye dielectric subjected to a sinusoidal voltage. co = 2nf... 

The microwave power dissipated inside a material is proportional to the dielectric loss factor (e"). The heat generated inside the material due to microwave can be... 

The amount of RF power dissipated in the soil is directly related to the frequency of the applied electric field, to the square of the amplitude, to the relative dielectric constant, and to the loss-tangent (8). 

In general, loss currents are a nuisance since they tend to heat up the dielectric and retard electromagnetic signals. The average power dissipated in a dielectric is... 

Power dissipation in a dielectric depends on both its dc conductivity and k". In general, a dielectric should be used at temperatures and frequencies that are as far removed as possible from a resonance or relaxation frequency. The composition should also be such as to minimize the dc conductivity. 

Intrinsic absorption. In Chap. 14 the power dissipation per unit volume in a dielectric was shown to be [Eq. (14.25)]... 

Loss angle (S) - For a dielectric material in an alternating electromagnetic field, 5 is the phase difference between the current and the potential difference. The function tan 5 is a measure of the ratio of the power dissipated in the dielectric to the power stored. 

The problem is totally different for dielectric loss. The wave is attenuated as it traverses the medium and, therefore, the power dissipated is reduced to an even larger extent. Consequently, the propagation constant becomes complex as described by Eq. (63) ... 

The increasing quantity of power dissipation per square unit as a result of the rising density of devices on PCBs leads to higher operating temperatures. Therefore, the thermal resistance of the applied adhesives has to correspond with the operating temperatures. Furthermore, a low dielectrical constant is essential for the adhesives and/or binders used for laminates because the heat dissipation is a result of dielectrical losses. 

Power, Dissipation, and Quality Factors Capacitor Reliability Aging and Radiation Effects Nonlinear Dielectrics and Nonlinear Capacitors... 

The power dissipated in the tube envelope because of dielectric loss... 

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