Chip-type capacitors

Chip-type capacitors are the main products due to their superior frequency performance and volumetric efficiency, which meet the requirements from the advanced electronics devices. A schematic diagram of the multilayer ceramic capacitor (MLC) is shown in Figure 5.1.1. The capacitor is composed of many thin plate capacitors in parallel connection. Thinning the dielectric layer, and stacking them maximum number into the limited thickness achieve maximum capacitance. The capacitance of the MLC of electrode area S, dielectric thickness t and number of dielectric layers n is given by... 

Fig. 6. A chip-type surface mount soHd tantalum capacitor.

The silicon diode (photodiode) detector consists of a strip of p-type silicon on the surface of a silicon chip (n-type silicon). By application of a biasing potential with the silicon chip connected to the positive pole of the biasing source, electrons and holes are caused to move away from the p-n junction. This creates a depletion region in the neighbourhood of the junction which in effect becomes a capacitor. When light strikes the surface of the chip, free... 

Multilayer technology is exploited just as for multilayer capacitors (see Section 5.4.3) to EIA size specifications, and inductor chips can be bandoliered ready for surface mounting, typical inductance values lying in the range 1 nH to about 20 /rH. They find important applications as EMI suppressors as well as for a wide range of applications as a lumped circuit component in equipment of all types -communications, entertainment , computers, etc. (see Fig. 9.17). 

These solid state detectors are multichannel devices. They have large number of photon-detecting registers. The registers are semiconductor capacitors that have been formed on a silicon chip. These detectors, which can detect very low levels of light, are primarily used in probe-type, near-infrared, and visible spectrophotometers and in fluorometers. 

The NdrYAG lasers are unable to interact with glass because the glass is transparent to the Nd YAG laser beam at the wavelength of 1.06 m. Therefore, no mark is possible with this beam. However, Nd YAG and Excimer do interact with ceramics, producing good contrasting marks. Ceramic, ICS, and ceramic chip capacitors are usually marked with these types of lasers. 

In electrical engineering, it is common to classify dielectrics in three main classes. Actually, dielectric materials are identified and classified in the electrical industry according to the temperature coefficient of the capacitance. Two basic groups (Class I and Class II) are used in the manufacture of ceramic chip capacitors, while a third group (Class III) identifies the barium-titanate solid-structure-type barrier-layer formulations used in the production of disc capacitors. 

Chip capacitors are constructed from a special oxide-based ceramic that is built up of alternating layers of ceramics and thin film layers that provide the device capacitance value. This capacitor is the multilayer thin film (MLTF) type. The second capacitor type has electrodes on the top and bottom surfaces of a homogenous block of ceramic. The ceramics used to make... 

The final applications discussed here are electrodes and metallizations for fine ceramics. This includes ohmic contact pastes for varistors and thermistors as well as materials for complex multilayer components. Figure 8.105 illustrates a cross-sectional view of a ceramic chip capacitor. The internal electrode can be Pt, Pd, or Ag-Pd depending on the type of ceramic formulation and its respective firing temperature. The end termination may be Ag or Ag-Pd and is typically required to be platable. The technical requirements of these materials are extremely challenging. 

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