Patent Application
20090186571
The invention relates to an automated air ventilation system for use with enclosures such as those used in semiconductor manufacturing and processing. More particularly, the device of the present invention comprises an automated ventilation system that enables an enclosure to only have the maximum flow rate when desired, for example, based on the presence or absence of one or more conditions that require a high flow rate.
Semiconductor manufacturing requires numerous gasses that are highly explosive, toxic, corrosive, or otherwise harmful. These gasses are typically found in numerous machines and processing tools that include enclosures that are used (in part) to prevent the gasses from escaping into the immediate working environment and causing harm. Allowing these gasses to build up within the enclosures can lead to explosions and releases of the toxic gasses into the surrounding environment.
To prevent gas buildup within the enclosures, a certain quantity of air must flow through the enclosures to properly scavenge and/or dilute the toxic gasses. Generally, this flow is the result of a draw point or a duct that is connected to a facility exhaust system that has a lower pressure than the atmosphere outside the enclosure. This pressure differential causes air to flow from outside the enclosure, through the inlet orifices to the exhaust system through the exit outlet or duct. An alternative method would be to have the exit vent in a room of lesser pressure than the room where the inlet vent is located. A ventilation system comprising an inlet vent and an outlet (such as an exhaust duct) in communication with the enclosure enables the flow rate within the enclosure. Certain exemplary pieces of semiconductor manufacturing equipment utilize billions of cubic feet per year of conditioned air to maintain the required flow rate for safe operation of semiconductor manufacturing equipment.
Maintaining a high flow rate can be expensive as the air used must generally be conditioned for temperature, humidity, particles, and other factors that are typically required in the manufacture of semiconductors. Such conditioning is costly and can exceed tens of thousands of dollars per machine on an annual basis.
That being said, it is not necessary to maintain a high flow rate at all times during a particular machine's operation. Typically, a high flow rate is only needed a very small percentage of the time that a tool is operating. For example, many semiconductor manufacturing tools require a high flow rate only three percent of the total operating time. Certain exemplary times when a high flow rate is needed include times when a technician gains access to the enclosure by removing an access panel or if an explosion, implosion or other similar event has already occurred within the enclosure and a gas release has occurred. For reasons of safety, the flow rate through these enclosures are typically set at “worst-case” conditions (where a high flow rate is required) and is therefore higher than is required for “general and/or least case” situations.
Because current semiconductor manufacturing tools utilize a high flow rate the entire time they operate regardless of whether such a high flow rate is actually needed, these tools consume a tremendous amount of energy and money. Therefore, an automated ventilation system for use with semiconductor manufacturing tools that selectively provides a high flow rate based upon the need for such a high flow rate is desired.
As set forth in the detailed description and accompanying figures, the present invention comprises, in various exemplary embodiments, a device configured to overcome a typical ventilation system's shortcomings by providing a system and device that adjusts the air flow within an enclosure used for semiconductor manufacturing based upon the occurrence of one or more conditions. As a result, the ventilation system of the present invention reduces the cost to operate semiconductor manufacturing equipment because of the reduced amount of conditioned air that is consumed.
In accordance with an exemplary embodiment of the present invention, an automated air ventilation system for use with semiconductor manufacturing equipment is provided. In accordance with one exemplary embodiment of the present invention, the ventilation system comprises an air inlet orifice restriction system that is configured to enable an air inlet to be in an open state to allow for a high flow rate and a restricted state to prevent a high flow rate. The ventilation system changes its orientation from a restricted state to an open state based on the occurrence of one or more conditions. Certain exemplary conditions comprise opening a door or removing a panel to gain access to the enclosure, or attempting to do the same by, for example, unlocking a locking mechanism on the panel or door, or the occurrence of an explosion, implosion, gas leak, or other similar event within the enclosure.
The subject invention will hereinafter be described in conjunction with the appended drawing figures, wherein like numerals denote like elements, and wherein;
The detailed description of various exemplary embodiments of the invention herein makes reference to the accompanying figures. While these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, it should be understood that other embodiments may be realized and that logical and mechanical changes may be made without departing from the spirit and scope of the invention. Thus, the detailed description herein is presented for purposes of illustration only and not of limitation. Additionally, while the disclosure herein describes the present invention used in connection with semiconductor manufacturing and processing, it should be noted that the air ventilation restriction system can be used with any ventilation system or area receiving circulating air.
In accordance with various exemplary embodiments of the present invention, an air ventilation restriction system for use with semiconductor manufacturing or processing equipment is disclosed. The air ventilation restriction system is configured to be used with an enclosure that houses one or more machines/tools used for semiconductor manufacturing along with numerous volatile or hazardous gasses that may be commonly present during any step of the semiconductor manufacturing process.
The ventilation system of the present invention is an automated or mechanically-operated system that adjusts vents on an enclosure from a restricted state to an open state based on the detection of a presence of one or more predetermined conditions that require a high flow rate within the enclosure. For example, the vents that can be adjusted include inlet, outlet, or any other type of vents that allow air to flow into or out of the enclosure.
In accordance with various embodiments, the ventilation system generally comprises an enclosure where semiconductors are manufactured or processed, the enclosure having various inlets, outlets, and a door or other access panel.
For example, more specifically, in accordance with an exemplary embodiment of the present invention and with reference to
Further, access panel 16 can be a door mounted by hinges to enclosure 12, a slideable door, a removable panel, or anything else that grants a user access to enclosure 12. Inlets 14 and outlets 18 can located anywhere on enclosure 12 such as a fixed panel that may form a sidewall of the enclosure 12 or on an access panel 16. The present invention also contemplates that the air drawn through the enclosure 12 is appropriately conditioned for semiconductor manufacturing.
In this exemplary embodiment, enclosure 12 further comprises exhaust pipes (not shown) and a filter 19 such as a HEPA filter which is configured to remove dirt, debris, and other contaminants from air that enters enclosure 12. Further, in one exemplary embodiment, air that enters enclosure 12 is conditioned for temperature, humidity, particles, and any other factor to make the air suitable for semiconductor manufacturing.
Further, while the present disclosure is directed at a specific embodiment where ventilation system 10 is used with semiconductor manufacturing equipment, ventilation system 10 can be used with any equipment or space that requires the use of conditioned air. Further, in yet other embodiments, ventilation system 10 can be applied to other applications where air may not be pre-conditioned but must be treated after it has exited a confined space such as enclosure 12.
As mentioned above, ventilation system 10 is an automated or mechanically-operated ventilation system for enclosure 12 that selectively adjusts the inlets 14 through which air and gases enter the enclosure 12 or the outlets 18 through which air and gases exit the enclosure 12 from a restricted flow rate to an open state, thereby allowing air to flow through the enclosure 12 at an unrestricted or higher flow rate. Ventilation system 10 is typically in a restricted state to avoid excessive consumption of conditioned air to reduce costs associated with conditioned air. In one exemplary embodiment, ventilation system 10 is configured to selectively adjust the inlet 14 through which air enters the enclosure 12. In other exemplary embodiments, ventilation system 10 is configured to selectively adjust outlets 18 through which air exits the enclosure 12. In yet another embodiment, the ventilation system 10 is configured to selectively adjust both the inlets 14 and outlets 18 of the enclosure 12 between a restricted state and an open state. It should be understood by one skilled in the art that when the inlets 14 and/or outlets 18 are in the open state, the inlets 14 and/or outlets 18 allow more air to flow therethrough relative to when the inlets 14 and/or outlets 18 are in the restricted state. It should also be understood by one skilled in the art that the term “open state,” as used herein, means that the inlets 14 and/or the outlets 18 are fully open such that the flow rate of gases flowing therethrough have little or no restriction. It should also be understood by one skilled in the art that the term “restricted state,” as used herein, means that the inlets 14 and/or outlets 18 are either partially or fully closed such that the flow rate of the gases flowing therethrough is less than the flow rate flowing therethrough when the inlets 14 and/or outlets are in the open state. In an embodiment, the inlets 14 and the outlets 18 can be independently adjustable between the restricted state and the open state. In another embodiment, the inlets 14 and ducts can be simultaneously and correspondingly adjustable between the restricted state and the open state.
In accordance with an exemplary embodiment of the present invention and with reference to
In one exemplary embodiment, actuator 20 is a guillotine style device and comprises a moveable panel 22 which is operatively connected to a driving mechanism 24. Driving mechanism 24 can be any mechanism configured to move moveable panel 22. Certain exemplary driving mechanisms include pneumatic devices, piston driven systems, air cylinders, electric motors, or any other such similar mechanism. While moveable panel 22 is depicted as a guillotine style blade in this exemplary embodiment, moveable panel 22 can be any device used to cover and/or obstruct gas flow through the inlets 14. In certain exemplary embodiments, an access door panel sensor is utilized and senses when movable panel 22 is about to be opened and operates ventilation system 10 to reduce pressure within enclosure 12 to enable access panel 22 to be opened easily.
In the normal operating conditions of the semiconductor tool having the enclosure 12, the inlets 14 are in a restricted state, thereby reducing the amount of conditioned air flowing through the enclosure 12. In certain exemplary embodiments, ventilation system 10 further comprises one or more sensors 11 that are operatively connected to actuator 20 that control the operation of actuator 20. When at least one sensor 11 detects the presence or absence of one or more sensed conditions, the inlets 14 are selectively adjusted from the restricted state to the open state to provide a high flow rate of gases through the enclosure to scavenge volatile undesirable gasses and/or other types of dangerous gasses that may be present within enclosure 12 or to generally dilute the gases within the enclosure 12.
For example, one sensed condition is when an operator of the equipment is attempting to gain or gaining access to enclosure 12 by attempting to open or remove access panel 16. Another exemplary sensed condition is when there is an integrity change within enclosure 12 that may result from an unusually high volume of volatile gasses, an explosion or an implosion within enclosure 12. In yet other exemplary embodiments, sensor 11 can detect whether or not the user desired that the inlets 14 be changed from a restricted state to an open state based on user input. As such, a user can selectively adjust the state of inlets 14 if they desire if none of the sensed conditions are present to automatically change the state of inlets 14. Certain sensed conditions comprise, but are not necessarily limited to, a changes in temperature within the enclosure 12, a change in pressure within the enclosure 12, a change of gaseous composition within the enclosure 12, a change in humidity level within the enclosure 12, a change in particulate level within the enclosure 12, a fire within the enclosure 12, an explosion within the enclosure 12, an implosion within the enclosure 12, a change in amount of a particular gas within the enclosure, and a change in percentage of a particular gas within the enclosure 12.
Sensors 11 may also detect the presence or absence of two or more conditions. For example, in such an embodiment, the first condition is whether or not a user is obtaining access to enclosure 12 based on movement or attempted movement of access panel 16 or a latch/lock used for opening access panel 16. The second condition is whether the integrity within enclosure 12 has been compromised by a release of toxic fumes, an explosion, an implosion, or any atmospheric change that would create an explosion or other risk within enclosure 12.
Upon sensing the presence of at least one sensed condition, the sensor 11 sends a signal to actuator 20 which directs the driving mechanism 24 to move the moveable panel 22 away from inlets 14 to adjust the inlet 14 to the open state to obtain a high flow rate of gases therethrough. When the sensed condition is no longer present as detected by sensor 11, a second signal is sent to actuator 20 which in turn directs that driving mechanism 24 move moveable panel 22 to return the inlet 14 to a restricted state. Alternatively, the lack of a signal from sensor 11 indicates that driving mechanism 24 should maintain the moveable panel 22 over the inlet 14 in a restricted state.
In accordance with an embodiment of the present invention and with reference to
In yet another exemplary embodiment, at least one sensor 11 is in communication with an operating mechanism that automatically operates access panel 16. When this operating mechanism begins move or remove access panel 16, sensor 11 sends a signal to actuator 20 to selectively adjust the inlet 14 from a restricted state to an open state (or vice versa) depending on whether access panel is being removed from enclosure 12 or replaced.
In another embodiment, the sensor 11 can be eliminated such that the actuator 20 is mechanically coupled or otherwise linked to access panel 16. In this exemplary embodiment depicted in
In this embodiment, access panel 16 is configured to move within the body of enclosure 12 upwards in the direction of arrows A. In other exemplary embodiments, access panel 16 can be moved downwards in the opposite direction than that depicted. In yet other embodiments, access panel can be moved side to side. This movement of access panel 16 moves both the coupling mechanism 28 and the driving mechanism 24, which in turn pulls moveable panel 22 upwardly to allow inlet 14 to be in the open state and enclosure 12 to have a high flow rate therethrough. When the door is moved back to the closed position, it in turn moves coupling mechanism 28 and driving mechanism 24 and moveable panel 22 back over inlet 14 placing inlet 14 in a restricted state.
In accordance with another exemplary embodiment of the present invention and with reference to
In other exemplary embodiments, rod 30 can be coupled to a motor instead of completely depending upon the movement of handle 26 or access panel 16. In yet other exemplary embodiments, at least one sensor 11 can be used as described above to send a signal to a motor coupled to rod 30 and operate the grate 21 of the inlet 14 as described above based on the presence or absence of certain conditions.
Besides the attempted or actual movement of the handle 26 or the access panel 16 in various embodiments, ventilation system 10 may be activated depending on whether or not the integrity within enclosure 12 has been compromised. As used herein, the term “integrity” denotes any change of atmosphere, gaseous composition, humidity level, particulate level, fire, temperature, explosion, implosion, pressure change, a certain amount of a particular gas, a percentage of a particular gas or any other atmospheric change they may occur within enclosure 12.
In this exemplary embodiment, a sensor 11 can sense the change of integrity within enclosure 12 and then send a signal to the actuator 20 (
In accordance with another exemplary embodiment and with reference to
As can be appreciated by one of ordinary skill in the art, pressure sensor 38 and temperature gauge 40 sense the pressure and temperature within enclosure 12. Further, the door sensor 36 senses whether or not access panel 16 has been moved or the operator intends to move the access panel 16 by gripping the handle 26 when the door sensor 36 is a capacitance sensor as described above. The signal generator 34 monitors the various inputs from sensors 36, 38, 40 and directs the ventilation system 10 to respond as outlined above. For example, if door sensor 36 indicated that a user's hand was on handle 26, or alternatively, if pressure sensor 38 indicated that pressure had increased dramatically within enclosure 12, the corresponding sensor would send a signal to the signal generator 34 that would determine the present state of the inlet 14 and determine if a signal should be sent to the actuator 20 to adjust the state of the inlet 14. For example, if the pressure sensor 38 senses a change in pressure within the enclosure 12, the pressure sensor 38 would send a signal to the signal generator 34. If the inlet 14 is currently in the restricted state, the signal generator 34 would send a signal to the actuator 20 to adjust the inlet 14 from the restricted state to the open state in which the flow rate of gas through the inlet 14 and the enclosure 12 is increased. If the door sensor 36 then senses a change in condition, such as an operator opening the access panel 16, the door sensor 36 would send a signal to the signal generator 34. However, the signal generator 34 verifies that the inlet 14 is already in the open state due to the previous pressure change and subsequent adjustment of the state of the inlet 14. In an embodiment, the signal generator 34 sends a signal to the actuator 20 to maintain the inlet 14 in the open state. In another embodiment, the signal generator would not send a signal to the actuator 20, thereby maintaining the inlet 14 in the open state. The signal generator 34 sends a signal to the actuator 20 to adjust the inlet 14 from the open state to the restricted state when the sensed condition of both sensors 36, 38 is no longer sensed by the corresponding sensor and the signal generator 34 receives a signal from both sensors 36, 38 indicating that the sensed condition is no longer present.
In accordance with another exemplary embodiment of the present invention and with reference
Alternatively, at decision point 46 the sensors 11 detect whether or not the integrity within enclosure 12 has changed in any way or been compromised. If yes, ventilation system 10 adjusts inlets 14 to the open state as described above. If no, ventilation system 10 ensures that inlets 14 remain in the restricted state.
Finally, various principles of the invention have been described in illustrative embodiments. However, many combinations and modifications of the above-described structures, arrangements, proportions, elements materials and components, used in the practice of the invention, in addition to those not specifically described, can be varied without departing from those principles.
