Communications: electrical – Condition responsive indicating system – Specific condition
Reexamination Certificate
2002-05-20
2004-05-18
Goins, Davetta W. (Department: 2632)
Communications: electrical
Condition responsive indicating system
Specific condition
C340S674000, C187S390000, C187S391000, C414S222010, C414S486000, C414S546000, C438S716000
Reexamination Certificate
active
06737980
ABSTRACT:
The present application claims priority under 35 U.S.C. § 119 to Korean Application No. 2001-0032697 filed on Jun. 12, 2001, which is hereby incorporated by reference in its entirety for all purposes.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for monitoring speed and operating time of a wafer lift of semiconductor fabricating equipment, and more particularly to an apparatus for monitoring speed and operating time of a wafer lift of semiconductor fabricating equipment that lifts wafers up/down.
2. Description of the Related Art
In general, a wafer handler of semiconductor fabricating equipment has a wafer cassette at a lift platform that is to be lifted up/down by a lift shaft. In order to monitor the operating speed of a wafer lift, an oscilloscope
12
is connected to a wafer lift interface circuit
10
, as shown in
FIG. 1
, so that the lift up/down speed time waveform shown in
FIG. 2
may be checked. A lift up/down speed time waveform is adjusted to be 650-750 msec by using a variable resistor mounted at a lift interface circuit
10
, if it is discriminated and confirmed that the lift up/down speed time waveform does not fall within a range of 650-750 msec.
In a conventional apparatus for checking the speed of a wafer lift, a waveform is maintained and measured as a cycle of only 0.3 seconds on the screen, due to impossibility of instant waveform capture of the oscilloscope. As such, there has been a variation in the wafer lift speed due to calibration error, which has negative influence on wafer handling.
Also, there are problems with the conventional method for measuring the lift up/down speed time, because using the oscilloscope requires a complicated procedure performed by a skilled engineer to accurately adjust the cycle. The measurement procedure takes a long time to perform, which deteriorates productivity. Furthermore, there is another problem with the conventional method in that overhaul or motor replacement of the wafer handler is required on designated days, which is inefficient from the standpoint of cost and labor.
SUMMARY OF THE INVENTION
The present invention is therefore directed to a wafer lift speed monitoring apparatus of semiconductor fabricating equipment which substantially overcomes one or more of the problems due to the limitations and disadvantages of the related art.
It is therefore an object of the present invention to provide a wafer lift speed monitoring apparatus of semiconductor fabricating equipment which automatically measures and indicates the speed of a wafer lift.
It is another object of the present invention to provide a wafer lift use time monitoring apparatus of semiconductor fabricating equipment that automatically indicates a period of time to use a wafer lift.
It is still another object of the present invention to provide a wafer lift operational state monitoring apparatus of semiconductor fabricating equipment that accurately checks the use time of a wafer lift after overhaul, so that efficient cost and labor effectiveness may be maintained without performing an overhaul or motor replacement on designated days.
In order to accomplish the aforementioned objects of the present invention, there is provided a wafer lift speed monitoring apparatus of semiconductor fabricating equipment including a lift interface circuit that transmits a motor driving signal; a signal interface that receives the motor driving signal output from a motor driving command output terminal of the lift interface circuit and outputs a shaped waveform signal responsive thereto; a high frequency oscillator that generates a high frequency signal; a division circuit that divides the high frequency signal into a divided frequency signal; a cycle sampling unit that samples the shaped waveform signal by a cycle unit of the divided frequency signal to estimate a time value of the shaped waveform signal; a memory that stores a reference lift speed time value; a display unit; and a controller that controls display of a lift up/down speed time value by the display unit based on the time value output from the cycle sampling unit and outputs a warning signal if the lift up/down speed time value as compared with the reference lift speed time value stored in the memory are confirmed not to correspond.
In order to accomplish the aforementioned objects of the present invention, there is also provided an apparatus for monitoring use time after overhaul of a lift of semiconductor fabricating equipment including a lift interface circuit having a variable resistor that transmits a motor driving signal to control the lift and a lift up/down speed time of the lift; a signal interface that receives the motor driving signal output from a motor driving command output terminal of the lift interface circuit and that outputs a shaped waveform signal responsive thereto; a time measurement reference circuit that periodically checks the shaped waveform signal, provides a counting termination signal if the shaped waveform signal is not detected, and provides a counting initiation signal if the shaped waveform signal is detected; a timer that counts use days and time after overhaul responsive to a predetermined control signal; a display unit; and a controller that controls the timer based on the counting initiation signal and that counting termination signal, and that controls display of the values of the counted use days and time after overhaul on the display unit.
In order to accomplish the aforementioned objects of the present invention, there is further provided a wafer number monitoring apparatus for a lift of semiconductor fabricating equipment including a lift interface circuit having a variable resistor that transmits a motor driving signal to control the lift and a lift up/down speed time of the lift; a signal interface that receives the motor driving signal output from a motor driving command output terminal of the lift interface circuit and that outputs a shaped waveform signal responsive thereto; a counting pulse generator that periodically checks the shaped waveform signal and that generates counting pulses at an interval of unit time responsive thereto; a counter that counts the counting pulses to provide a counted value; a display unit; and a controller that controls display of a number of wafers processed on the display unit responsive to the counted value.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
REFERENCES:
patent: 4859993 (1989-08-01), Kagami et al.
patent: 5206627 (1993-04-01), Kato
patent: 5900062 (1999-05-01), Loewenhardt et al.
patent: 6485248 (2002-11-01), Taylor, Jr.
Goins Davetta W.
Samsung Electronics Co,. Ltd.
Volentine & Francos, PLLC
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