JP2009250959A - Filter monitoring system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent failures of an electronic part or the like by monitoring the time deterioration state of a gas phase adsorbing filter set within a casing or container in real time by a sensor. <P>SOLUTION: A sensor element of a QCM (quartz crystal microbalance) is mounted in the vicinity of the gas phase adsorbing filter of silica gel or activated carbon installed within the casing to temporarily measure the gas phase material adhesion accumulation quantity to the sensor, whereby a correlation database with a preliminarily acquired temporal accumulative adsorption quantity of the gas phase material to the filter corresponding thereto is used to estimate the accumulative adsorption quantity of the gas phase material to the installed filter in real time, and further the deterioration state of the filter performance can be warned. Consequently, failures of the electronic part or an electronic device mounted therewith resulting from overlooking of deterioration of the gas phase filter can be prevented. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a system for monitoring the characteristics of a gas-phase adsorption filter installed inside a housing or a container, and more particularly to monitor the deterioration of a gas or humidity (water vapor) adsorption filter over time with a sensor. Related to the system.

  There are many precision electronics devices such as magnetic recording devices, transport storage containers for storing and transporting electronic components, and containers for storing and transporting semiconductor wafers during process processing. In this case, a vapor phase adsorption filter mainly composed of silica gel or activated carbon is installed for the purpose of control including moisture removal of the humidity inside the housing, removal of harmful gases that enter the housing, or enter from the outside. Has been.

  These vapor phase adsorption filters estimate in advance the type and concentration of water vapor or gas contained in the apparatus casing or container from the beginning, or generated or invaded with time. Then, the type and amount of silica gel and activated carbon, and their mixing ratio, which are sufficient to remove or control gas phase substances such as water vapor and gas that are harmful to these devices and parts over a long period of time, are designed. The phase adsorption filter is mounted in the housing.

On the other hand, for the detection of gas phase substances such as generated gas in closed spaces such as the above-mentioned device housings and containers and in the space where the gas phase flows, etc. A sensor using a quartz crystal is installed, and the change in weight over time caused by the deposition of substances such as molecules or atoms in the gas phase or electrode corrosion by harmful gas molecules at the electrode on the surface of the crystal. It is proposed to detect and measure the amount of molecules or atoms in the gas phase such as water vapor and gas (hereinafter referred to as gas phase materials) by measuring the change in the vibration frequency of the quartz crystal due to (For example, Patent Documents 1 and 2).
JP 2004-47929 A JP 2007-35180 A

  As described above, the design of the gas-phase adsorption filter mounted in the housing (or container) is performed by assuming certain environmental conditions. Therefore, it is conceivable that the content of the filter to be mounted varies greatly depending on the external environmental conditions.

  For example, when the external environment of the enclosure is high temperature or high humidity, or when the enclosure is placed near a source of corrosive gas, etc., use the cooling fan or vent of the enclosure. As such outside air enters, the adsorption of substances such as molecules or atoms (gas phase substances) in the gas phase rapidly progresses and approaches the adsorption capacity performance limit of the filter. It is assumed that a situation occurs in which the adsorption performance decreases. If it becomes like this, possibility that the performance deterioration of the electronic components etc. inside a housing | casing (container) will be caused becomes high.

  However, it is usually difficult to check the condition of the filter once installed in the housing from the outside. For example, the corrosion of the stored electronic parts or the occurrence of a device failure of the magnetic recording device is finally detected. A phenomenon that it is understood that the performance of the filter has deteriorated frequently occurs.

  Accordingly, one aspect of the problem of the present invention is to enable monitoring of a deterioration state over time of a gas-phase adsorption filter characteristic installed inside a housing or a container from the outside. A filter monitoring system that issues information about the timing of replacement of the product, or monitors the possibility of deterioration or failure of electronic parts built in the case or container, or alerts the occurrence of failure caused by it It is to provide.

The filter monitoring system of the present invention includes:
A filter monitoring system for measuring performance deterioration of a gas phase adsorption filter housed in an electronic device casing,
A measuring means provided in the electronic device casing and provided with a detection element for adsorbing a gas phase substance in the electronic device casing;
Storage means for storing an adsorption correlation database indicating a relationship between an adsorption amount of the gas phase substance in the previous detection element and an adsorption amount of the gas phase substance in the gas phase adsorption filter;
And means for calculating the amount of the gas phase substance adsorbed on the gas phase adsorption filter based on the output signal from the measuring means and the adsorption correlation database.

  According to the present invention, for example, it becomes possible to monitor the deterioration state of the performance of the gas-phase adsorption filter in real time, to issue a warning about the replacement time of the filter, or to an electronic component built in the housing or container, etc. Information such as monitoring of the possibility of deterioration and failure or warning notification of failure caused by it can be issued in a timely manner and without taking out and inspecting the filter outside before it is too late. .

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

(Example)
FIG. 1 is a schematic diagram for explaining one configuration of the filter monitoring system of the present invention. FIG. 1 (1) schematically shows a magnetic recording apparatus 1, and electronic components such as a magnetic recording medium 3 and a magnetic head 4 are contained in a casing (or container) 2 of the apparatus. Further, in the housing 2, for example, a silica gel filter 5-1 mainly composed of silica gel for mainly adsorbing water vapor and controlling humidity in the housing, and mainly adsorbing gas components in the housing. A filter 5 for adsorbing a substance (hereinafter referred to as a gas phase substance) such as a molecule or an atom in a gas phase state such as water vapor or gas is mounted. The adsorbed water vapor or gas (especially harmful gas) is inherent in the device casing 2 from the beginning, or is generated with time from the internal device, and from the outside of the housing 2 from the intake port, exhaust port, etc. There are things that invade.

  A sensor 6 composed of two types of sensors (detection elements) is mounted in the housing 2 in the vicinity of the filter 5 for gas phase adsorption. That is, the silica gel sensor 6-1 is a sensor corresponding to the silica gel filter 5-1, and the activated carbon sensor 6-2 is a sensor corresponding to the activated carbon filter 5-2.

  FIG. 1 (2) shows a similar magnetic recording device 1, in which a silica gel and activated carbon mixture filter 5-3 is mounted in a housing 2 in which electronic components such as a magnetic recording medium 3 and a magnetic head 4 are present. A case is shown, and a corresponding mixture sensor 6-3 is mounted in the vicinity thereof.

  The magnetic recording apparatus 1 configured as described above is incorporated into a storage box 8 of an information processing apparatus 7 such as a personal computer schematically shown in FIG. In the storage box 8, information from the sensor 6 in the magnetic recording device 1 can be read by a sensor data reader 9, and this read data is stored in a storage device (or magnetic recording device 1 or the like) not shown. The control circuit 10 performs comparison processing and the like stored in the database, and the result can be displayed on the display device 11.

  As the sensor (detection element) 6, a quartz crystal resonator having a piezoelectric effect is used as a sensor element, and fluctuations in oscillation frequency caused by gas phase adsorption or separation from the electrode forming film of the transducer are used to It can be used as a measuring device for the deposition of phase material. A QCM (Quartz Crystal Microbalance) can be used as such a vapor phase material deposition measurement apparatus (for example, Patent Documents 1 and 2).

  In this measuring device, when the mass of the electrode-forming film increases or decreases due to the deposition, separation, or chemical reaction of the gas phase material on the electrode-forming film of the sensor, the oscillation frequency of the vibrator decreases according to the change. Or increase. Therefore, by observing the change over time of the increase / decrease, it is possible to measure the accumulated change amount of the deposition / desorption or chemical reaction of the vapor phase substance.

  In this embodiment, the metal film in the electrode forming film of the quartz crystal sensor element of the QCM is, for example, Ag (silver), Au (gold), or Pt (platinum), and further, the same as the filter material or A film of the same material is additionally formed in advance. As an additional membrane material, silica gel sensor 6-1, activated carbon sensor 6-2, and mixture sensor 6-3 are respectively mixed with silica gel, activated carbon, and a mixed material of silica gel and activated carbon having the same mixing ratio as the filter as described above. Use it. By forming such an additional film, the reaction of depositing or desorbing the vapor phase substance generated in the vapor phase adsorption filter can be reproduced and measured on the surface of the sensor element.

  Next, the quartz crystal sensor element of QCM and the gas phase adsorption filter having the electrode forming film thus formed are arranged in the same casing (or container). In the housing environment, first, a change with time of the deposition / desorption of the vapor phase substance on the sensor is measured. This is possible by measuring the cumulative change amount of the oscillation frequency of the vibrator (that is, equivalent to the result of the deposition amount on the sensor).

  At the same time, the cumulative amount of adsorption of a gas phase substance such as gas or water vapor, which is adsorbed in the actually mounted filter in the casing (container), is measured. In this way, the relationship between the adhesion / deposition amount of the vapor phase substance on the sensor and the accumulated adsorption amount of the vapor phase substance in the filter is obtained, and a correlation database is created.

  The amount of adsorption in the filter is measured by measuring changes in the concentration of each component over time using, for example, a thermohygrometer for water vapor and an analytical instrument such as a gas sensor or gas chromatograph for gas. The relationship of the accumulated absorption amount of the gas phase with respect to time can be obtained.

  An example (standardized) showing the relationship between the two obtained is shown in FIG. In this figure, the horizontal axis represents the amount of deposition of vapor phase substances such as water vapor and gas obtained from the cumulative change in the oscillation frequency of the vibrator, and the vertical axis represents the gas phase of the gas phase adsorption filter with respect to it. This is the cumulative amount of adsorption of the substance.

  The relationship diagram shown in FIG. 2 shows the amount of water vapor in the housing regardless of the quantitative relationship or the time interval, that is, even when a large amount of gas phase is suddenly generated or stopped, for example. If there is a change in the gas phase state, such as invasion or generation of gas, the amount of adsorbed deposition of the gas phase substance on the sensor is continuously measured, so that the adsorption of the gas phase substance in the built-in gas phase adsorption filter is performed. The cumulative amount can be estimated.

  As can be seen from the tendency of the solid line in the figure, the adsorption performance stage of the three stages of filters is generated with the increase in the amount of deposition on the sensor. First, in the initial stage of use of the filter, that is, in the range of (I) normal state of the filter in the figure, the cumulative absorption amount in the filter increases linearly in proportion to the amount of accumulated deposits on the sensor, that is, the gas phase substance. It indicates that the adsorption is in proportion to the amount of intrusion, so to speak, it is operating in a normal state as an adsorption filter, and there is still a margin in the adsorption capacity. In the stage after the filter has been used to a certain extent, that is, in the range of (II) filter performance degradation state in the figure, the accumulated absorption amount in the filter is not proportional to the amount of accumulated deposits on the sensor, and the adsorption force gradually increases. Decreases. Therefore, the adsorption performance of the filter is lowered, indicating that the filter cannot be used in a normal state. That is, the gas phase material to be adsorbed is not completely adsorbed. When the filter is further used, that is, in the range of (III) filter breakthrough state in the figure, the adsorbent performance reaches the limit, and the target substance to be removed but the gas phase substance starts to flow out of the filter. In this state, the accumulated absorption amount of the filter is substantially constant and saturated with respect to an increase in the amount of adhesion and accumulation on the sensor.

  Example of measurement results when the deposition amount (vertical axis) of the vapor phase substance on the sensor is measured in real time along with the elapsed time (horizontal axis) with the filter and sensor mounted in the case (container) at the same time (Normalized) is shown in FIG. For example, the deposition amount of the vapor phase substance on the sensor in the range of time lapse (A) is the deposition amount of the vapor phase substance on the sensor in the range of (I) in FIG. 2 corresponds to the range of (II) in FIG. 2 and the amount of deposition and deposition of the vapor phase substance on the sensor in the range of time (C).

  In this way, by measuring the amount of vapor deposition of the vapor phase substance on the sensor over time, the state of the adsorption performance in the filter can be changed to the state (I), the state (II), the state (III ) Can be determined.

  The acquired relationship of FIG. 2 is made into a correlation database and stored in the storage device of the information processing apparatus 7 shown in FIG. 1, for example. Then, regarding the state of the adsorption performance of the filter 5 in the magnetic recording device 1 in the information processing device 7, information on the cumulative change amount of the oscillation frequency of the vibrator from the sensor 6 (that is, the deposition amount of the vapor phase substance on the sensor) is obtained. Based on the correlation database showing the relationship between this value and the storage device (not shown) in FIG. 2, which is read in real time using the sensor data reader 9, the accumulated amount of vapor phase deposit on the filter is calculated, For example, a filter monitoring system in which the result is displayed on the display device 11 of the information processing device 7 can be constructed.

  Further, for example, when the accumulated amount of vapor phase material deposited on the filter, which is calculated based on the deposited amount of the sensor, falls within the range of the value of the filter performance degradation state in FIG. FIG. 3 (III) A filter monitoring system having a filter replacement alarm system that issues a filter replacement warning when the value of the filter breakthrough state is reached can be constructed.

  FIG. 4 shows a flowchart example of the filter replacement alarm system. First, the filter replacement alarm system is started at the start of step 1, and the filter performance is monitored in real time by the sensor by the sensor monitoring of step 2. After a certain period of time has elapsed since the start of filter use, the filter state is determined by the sensor in Step 3, and the amount of vapor-deposited material deposited on the previous sensor (vertical axis) is measured in real time. The accumulated amount of vapor phase material is determined and judged. When the value is in the range of (I) normal filter state, the filter normal state is determined in step 4 and the use of the filter is continued. In step 1, sensor monitoring is performed again. (II) When the filter performance falls within the range, the filter performance in step 5 is lowered, and a warning is given (to the display device or the like) so as to facilitate the replacement filter. When the range of the filter breakthrough state is reached (III), the filter in step 6 is broken, and a warning is given to replace the filter immediately.

  In addition, (II) when the performance of the filter is degraded, especially when it is in the range of (III) filter breakthrough, if this state continues, the electronic components inside the housing and the container will deteriorate, and the electronic components There is a high possibility that it will be associated with the failure of the mounting device or the failure of the mounting device based on it. Therefore, such a filter monitoring system based on the amount of accumulated deposition on the sensor is used as a means for monitoring the occurrence of a failure of an electronic component, or a means for notifying the occurrence of a device failure, and the necessity of data backup when the device is a magnetic recording device. It can also be constructed as an additional function system as a warning notification means.

  In the above description, the filter monitoring has been mainly performed in a housing such as a magnetic recording device, but of course, the present invention is not limited to this. The housing in which the gas phase adsorption filter is built in includes, for example, a housing (container, box) for transporting and transporting semiconductor manufacturing substrates, electronic components (including precision equipment components), and the like. Even in such a case, the above-mentioned monitoring sensor is incorporated at the same time. For example, instead of the above-mentioned personal computer, a small data logger is attached to the gas phase substance in the sensor being transported or transported. By recording data on the amount of deposits and analyzing the performance of the filter in the same way as described above, for example, the state of the filter for gas-phase adsorption at the delivery destination, as well as the occurrence of abnormalities in built-in components, etc. Can know the presence or absence of sex.

  As described above, conventionally, it has not been possible to easily or in real time grasp the deterioration in performance over time of a gas-phase adsorption filter in a casing or container. However, the filter monitoring system of the present invention measures the amount of vapor deposition on the sensor using a monitoring sensor such as a QCM using a small and high-accuracy quartz crystal resonator, so that it can be obtained with a filter obtained in advance. From the relationship with the accumulated absorption amount, it was possible to easily obtain the accumulated adsorption amount of the gas phase substance in the gas phase adsorption filter, and to easily grasp the deterioration level of the adsorption performance of the filter in real time. Further, it is possible to easily extend the function to a warning system for a failure of an electronic component in the casing (container) and a failure of a device using the electronic component.

The figure explaining the filter monitoring system of this invention The figure explaining the relationship between the gaseous-phase substance adhesion deposition amount to a sensor, and the gaseous-phase substance cumulative adsorption amount to a filter A diagram for explaining the relationship between the elapsed time and the amount of vapor phase material deposited on the sensor The figure explaining the flowchart of a filter exchange alarm system

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Magnetic recording device 2 Housing | casing 3 Magnetic recording medium 4 Magnetic head 5 Filter 6 Sensor 7 Information processing apparatus 8 Storage box 9 Sensor data reader 10 Control circuit 11 Display apparatus

Claims (5)

A filter monitoring system for measuring performance deterioration of a gas phase adsorption filter housed in an electronic device casing,
A measuring means provided in the electronic device casing and provided with a detection element for adsorbing a gas phase substance in the electronic device casing;
Storage means for storing an adsorption correlation database indicating a relationship between an adsorption amount of the gas phase substance in the previous detection element and an adsorption amount of the gas phase substance in the gas phase adsorption filter;
A means for calculating an amount of the gas phase substance adsorbed on the gas phase adsorption filter based on the output signal from the measurement means and the adsorption correlation database;
A filter monitoring system comprising: The detection element has a structure in which a film containing a material for the gas phase adsorption filter is laminated on an electrode of a vibrator made of a crystal piece having a piezoelectric effect,
The filter monitoring system according to claim 1, wherein the measurement unit outputs an electrical signal that varies according to an oscillation frequency of the measurement element as an output signal.   3. The filter monitoring system according to claim 1, wherein the adsorption material contained in the gas phase adsorption filter is made of either silica gel or activated carbon, or a mixture of silica gel and activated carbon.   4. The filter monitoring system according to claim 1, wherein the electronic device casing is a magnetic recording device casing or an electronic component transport container. The storage means further stores a failure correlation database indicating a relationship between a failure rate of the electronic component and an adsorption amount of the gas phase substance in the gas phase adsorption filter, an output signal from the measurement means, and the failure 5. The filter monitoring system according to claim 1, further comprising means for determining a failure of the electronic component based on a correlation database.

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