Abstract: A wet chemical process tank, or a wet etch tank, that has improved fluid circulation and improved uniformity in the fluid concentration in the tank is disclosed. In a preferred embodiment, a tank body is provided which has a liquid dispenser positioned therein with a plurality of liquid outlets in a vertical surface of the dispenser each having a different diameter opening for compensating the different fluid pressure in the dispenser. A more uniform liquid concentration is thus achieved in the tank cavity to perform a more uniform chemical process on the plurality of wafers. The tank body is further provided with a second endwall which has a second distance from the plurality of wafers that is at least twice the first distance between a first endwall and the plurality of wafers. When the second endwall is at least 0.

Abstract: A wet chemical process tank, or a wet etch tank, that has improved fluid circulation and improved uniformity in the fluid concentration in the tank is disclosed. In a preferred embodiment, a tank body is provided which has a liquid dispenser positioned therein with a plurality of liquid outlets in a vertical surface of the dispenser each having a different diameter opening for compensating the different fluid pressure in the dispenser. A more uniform liquid concentration is thus achieved in the tank cavity to perform a more uniform chemical process on the plurality of wafers. The tank body is further provided with a second endwall which has a second distance from the plurality of wafers that is at least twice the first distance between a first endwall and the plurality of wafers. When the second endwall is at least 0.

Abstract: An improved control device for power factor corrections contains a voltage-raising circuit, a pulse width modulator to control the conduction of the voltage-raising circuit and an AC reference voltage circuit to control the output of the voltage-raising circuit. The AC reference voltage circuit consists of an error amplifier and a comparator connecting to an output port of the error amplifier. The voltage-raising circuit outputs a voltage to the error amplifier. The output port of the comparator connects to the output port of a full-wave rectifier through a set of voltage dividers and capacitor. Therefore, the output voltage of the AC reference voltage circuit conforms to the input voltage of the voltage-raising circuit, achieving the objective of correcting the power factor.

Abstract: A switched power supply, which can effectively detect and monitor the power supply to electrical appliances and terminate the power supply if any abnormal overpower phenomenon occurs, is disclosed. The switched power supply includes a detecting and processing unit connected between an output end of the switched power supply and a wave width modulator of the power supply for detecting an output power of the switched power supply. The detecting and processing unit includes an overpower detecting circuit for determining whether the output power of the switched power supply exceeds a set value, and a timing circuit for determining whether the duration of overpower phenomenon exceeds a set time period and switching off the wave width modulator if the set time is exceeded.