Gate cross-section

The velocity of the flowing material in the area of the fan gate should not be greater than 1 5m s" otherwise the liquid will enter the mould cavity in a turbulent manner. This velocity value holds for polyol viscosities of 100-600 cP at 25°C. For lower viscosity materials, the film gate cross-section must be increased or the throughput decreased to maintain laminar flow. 

Injection pressures 1000-1700 bar Secondary pressure should be sufficiently high and of sufficient duration Gate cross-sections should be made sufficiently large, so that sealing does not occur too early (see POM)... 

Figure C2.16.9. Schematic cross-section and biasing of a metai-oxide-semiconductor transistor. A unifonn conducting channei is induced between source (S) and drain (D) for > V. Voitage is appiied between the gate (G) and the source. Part (A) shows the channei for - V the transistor acts as a triode. The source-...

Valves have two main functions in a pipeline to control the amount of flow, or to stop the flow completely. There are many different types but the most commonly used are the gate valve and the globe valve. The gate valve contains a disk that slides at right angles to the flow direction. This type of valve is used primarily for on-off control of a liquid flow. Because small lateral adjustments of the disk cause e.xtreme changes in the flow cross-sectional area, this type of valve is not suitable for adjusting flow rates. 

Common problems like insufficient filling-packing and poor dimensional control are often related to the gate size and design. Similarly, gate location is another important factor. They should be located in areas having heaviest cross-section of the part to assure fill-out and elimination of sink marks. Also their position should not facilitate the residual molded stress formation in the part, knit line formation. 

The most common a-Si H TFT structure is the so-called inverted staggered transistor structure [40], in which silicon nitride is used as the gate insulator. A schematic cross section is shown in Figure 74. The structure comprises an a-Si H channel, a gate dielectric (SiN.v), and source, drain, and gate contacts. 

Figure 12.9. Micrographs of a cross section of a three-layer construction (source/ dielectric/gate) for a transistor fabricated by graphic arts printing technologies.

Figure 10. cross sectional view of a GASFET where the CIM is deposited underneath the gate. 

Another innovation related to power SiC DMOSFET was a transistor structure, where the p-type base region was not electrically shorted to the source but could be biased independently as a p-type gate. Such a configuration, equivalent to plugging a VJFET fed from an accumulation channel in parallel with a BJT, resulted in a dramatic reduction of specific on-resistance. A schematic cross section of this device, denoted as static induction injected accumulated FET (SIAFET) and reported by Sugawara et al. in 2000 [40], is shown in Eigure 5.12. 

Figure 5.12 Schematic cross section of SiC SIAFET. Buried P region under the source is connected to P gate in third dimension.

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