JP4001581B2 - Pinhole detection and transmission measurement device - Google Patents

Description

  The present invention relates to a detection apparatus for detecting / presence of pinholes existing in a thin film such as a plastic film and measuring gas (gas) permeability of the thin film.

  Known methods for measuring pinholes in plastic films, plastic containers, and the like include light transmission and reflection methods, capacitance change detection methods, and discharge detection methods. For example, the light from the light source is irradiated onto the inspection object, the light amount of the passing light from the inspection object is detected by the light detector, and the pinhole in the inspection object is based on the light amount value detected by the light detector There is known an apparatus for determining the presence or absence of an image (for example, see Patent Document 1).

  Conventionally, as a method for measuring the gas permeability of a thin film, a part of a film is cut out, the film is sandwiched between two chambers, both chambers are decompressed, and then a test gas is introduced into one chamber. A method (differential pressure method) is known in which a pressure gauge is provided in the chamber and the amount of test gas permeated through the film is measured. (For example, refer nonpatent literature 1.).

JP 9-318558 A JIS K7126 Test method for gas permeability of plastic film and sheet

The conventional pinhole measurement method is mainly intended to detect the pinhole position, and cannot measure the gas permeability of the membrane.
In addition, the thin film gas permeability measuring device requires time to sandwich the thin film between the two chambers.

  Furthermore, in the case of the conventional differential pressure method, the vacuum is sufficiently evacuated before the measurement so that the pressure in the chamber at the initial stage of the measurement changes only due to the factor of the thin film permeating gas. The time required for this evacuation is about 1 to 2 hours. When the measurement is started, the relationship between the pressure in the chamber and the measurement time (permeation curve) rises in a downwardly convex curve and then becomes a linear state. Since the gas permeability is measured after waiting for this linear state, that is, the steady state, it takes 10 minutes (in the case of a thin film with high permeability) to several tens of hours (in the case of a thin film with low permeability). is there.

  On the other hand, the amount of gas permeation (permeability) of the electrolyte membrane used in fuel cells and the like is one of the important factors in configuring a fuel cell. There is a need to manage the amount of transmission.

Based on such a situation, the present invention provides an apparatus capable of simultaneously measuring pinhole detection, pinhole presence / absence determination, and gas permeability measurement. In addition, it is possible to provide a device that can easily set a test film and take out individual thin films stacked in multiple layers, and can detect pinholes, determine presence / absence, and measure transmittance in a short time. Is.
Other problems of the present invention will become apparent from the following description of the invention.

  In order to solve the above-described problems, the present invention provides a transmission cell having a transmission surface for adsorbing a test object to the transmission surface, a pressure sensor for measuring the pressure in the transmission cell, and vacuum suction in the transmission cell. A vacuum pump, an opening / closing means for closing the permeation cell after the permeation cell is sucked by the vacuum pump, a measured value of the pressure sensor is calculated, and a pinhole of the device under test is calculated from the calculated value And a calculator for calculating the gas permeability of the device under test, and a moving means for relatively changing the distance between the mounting surface of the device under test and the transmission surface of the transmission cell. Provided pinhole detection / transmittance measuring device.

  The test object is an electrolyte membrane, a plastic film, a sheet, a processed paper, a light shielding film, and the like, and is not particularly limited. Although the thickness of a to-be-tested object is not specifically limited, For example, in the case of an electrolyte membrane, the thickness of 50-200 micrometers is preferable. Further, the size and area are not particularly limited, but it is necessary that the surface of the transmission cell be larger than the surface to be adsorbed. In other words, it is possible to create a transmission cell having a transmission surface to be tested having an arbitrary size and a surface for adsorbing the test sample. The test object is preferably a plurality of stacked sheets, but even a single sheet can be measured in the same manner.

  The permeation cell is a container having a hollow inside, and is provided with a support member that supports a device under test on a surface layer portion of the cavity. The support member is provided in order to avoid tearing or deformation of the test object when the test object that is a thin film is vacuum-adsorbed and the transmission cell is evacuated. The supporting member is not particularly limited as long as gas passes and the device under test stops on its surface. For example, a sintered filter, a ceramic filter, a net, or the like can be used. The pore diameter of the filter or the like is usually several to several hundred μm, preferably 30 to 70 μm.

As the pressure sensor, a pressure sensor capable of measuring pressure over time, for example, a vacuum gauge using a piezoelectric element, a diaphragm electronic sensor, a vacuum gauge using a change in heat conduction, or the like can be used.
The vacuum pump is preferably a pump that can exhaust the gas in the permeation cell to a pressure of about 0.00X KPs, and a turbo molecular pump, an oil rotary pump, or the like can be used.
As the opening / closing means, a valve that can be opened and closed instantaneously, such as an electromagnetic valve or an air valve, can be used, and it may be operated remotely.

  The computing unit calculates the gas permeability of the device under test from the measurement value of the pressure gauge. Further, the presence / absence of a pinhole is determined by determining the calculated gas permeability value. The computing unit is composed of, for example, a computer and a program.

The surface direction of the mounting surface of the device under test is not particularly limited, and may be a horizontal surface or a vertical surface. Preferably, the surface direction of the mounting surface is a surface that intersects the horizontal plane at an intersection angle of ± 30 degrees or less. In the case where the mounting surface is vertical or nearly vertical, it is preferable to provide appropriate holding means for holding the device under test.
Further, the mounting surface is preferably a flat surface, but may be a curved surface.

The transmissive surface of the transmissive cell is in contact with the mounting surface, and the angle of intersection with the mounting surface is usually ± 30 degrees or less, preferably ± 15 degrees or less, and more preferably ± 5 degrees or less. To do. This is because the entire surface of the test object may be adsorbed on the transmission surface substantially simultaneously, or may be adsorbed in order from the portion closest to the transmission surface.
Furthermore, the transmission cell and / or the mounting surface may be held via a tilting means. In this way, the transmission surface and the placement surface can be brought into contact in a parallel state. The tilting means holds, for example, the back side of the tray that forms the placement surface with an elastic body such as three helical springs.

The moving means for changing the distance between the mounting surface of the test object and the transmission surface of the transmission cell relatively changes the distance between the mounting surface of the test object and the transmission surface of the transmission cell. One piece at the top of a plurality of test specimens placed in a stacked state is vacuum-sucked, and a gap between the sucked one piece and the remaining test specimens is opened so that the permeation of the test specimens is achieved. Measurement is performed with the surface opposite to the surface adsorbed on the surface open.
The moving means may be structured to move the mounting surface of the test object. Moreover, it can be set as the structure which moves a permeation | transmission cell. Furthermore, it can be set as the structure which moves both the mounting surface of a to-be-tested object, and a permeation | transmission cell.
When the placement surface is leveled, these moving directions are up and down directions. Further, when the placement surface is vertical, these moving directions are the left and right directions.

  According to the present invention, the transmission cell is brought into contact with the device under test with the above configuration, and the device under test is attracted and fixed to the transmission surface of the transmission cell due to the pressure reducing effect. By configuring in this way, what has conventionally required a long time to set the device under test can be automatically set in a short time.

Next, a space is formed between the one test object adsorbed on the permeation cell and the remaining test object or the mounting surface of the test object, and the back surface of the test object is opened to the atmosphere. And evacuate the transmission cell simultaneously and / or subsequently.
The opening / closing means is closed while the vacuum pump is operated, and the evacuation in the permeation cell is stopped. Gas (air) that permeates the DUT or gas that leaks from the pinhole increases the pressure in the permeation cell. The pressure is measured by a pressure sensor, the presence or absence of a pinhole is determined from the pressure measurement value, and the gas permeability of the device under test is calculated.

If a pinhole is detected, it can be programmed to end the measurement at that point and move to the next measurement of the device under test.
When the measurement is finished, if the air is introduced into the transmission cell by operating the opening / closing means of the transmission cell, the device under test falls naturally. The introduction of the air may be performed by stopping the operation of the vacuum pump and waiting until the inside of the permeation cell becomes atmospheric pressure and the test object falls.
By comprising in this way, the apparatus which can perform the detection of the pinhole of a thin film and the measurement of the transmittance | permeability rapidly is provided.

  In a preferred embodiment of the pinhole detection / transmittance measuring apparatus, the moving means may be a moving means for moving the transmission cell up and down. In this way, it is not necessary to provide a special test object mounting surface (that is, a mounting table). When only the permeation cell is moved up and down, the pressure sensor and the opening / closing means are connected to the permeation cell by a flexible pipe.

In a preferred embodiment of the present pinhole detection / transmittance measuring apparatus, the transmission cell, the pressure sensor, and the opening / closing means may be integrated. The integral structure means a structure in which the permeation cell, the pressure sensor, and the opening / closing means can be moved by one moving means, and does not necessarily have to be manufactured by one casing.
When continuously measuring multiple DUTs, a tray for acceptable products and a tray for rejected products are prepared, and the transmission cell moves upward after each measurement of one DUT. Thus, one tray corresponding to the measurement result can be positioned immediately below the transmission cell, the vacuum suction of the device under test can be released, the device under test can be dropped onto the tray, and the device under test can be classified. This tray selection and positioning can be done manually or can be automated.

  Further, in a preferred embodiment of the present invention, the transmission cell or the transmission cell, and the pressure sensor are provided with moving means that can move in the biaxial direction of one axis perpendicular to the vertical axis (Z axis) and the Z axis. And the integral structure of the opening / closing means may be movable in two axial directions. Further, the moving means can be a means capable of moving in the three axial directions of the space. Here, the three axes of space refer to the vertical axis (Z axis), the vertical axis (X axis), the horizontal axis (Y axis), and the X, Y, and Z axes intersect at an intersection angle of 90 degrees.

  Such moving means includes, for example, first, second, and third guide members extending in the X, Y, and Z axis directions, and first, second, and second guide members that are movable by being guided by the respective guide members. 3 moving members. The first, second, and third guide members are attached to the base, the first moving member, and the second moving member, respectively. An instrument holder for holding either the transmission cell or the above-described integrated structure is attached to the third moving member. Each moving member is provided with a driving means for driving in each moving direction. Therefore, by controlling the drive amount of the drive means, the instrument holder can be moved in three dimensions. As the driving means, for example, a screw shaft extending in the moving direction of the moving member, a nut fixed to the moving member and screwed to the screw shaft, and a stepping motor that rotationally drives the screw shaft may be used. it can. Further, an electromagnetic force driving system using a coil and a magnet as driving means can be adopted. In addition, a hydraulic drive system, a mechanical system, or the like can be employed.

The first, second, and third guide members preferably intersect at an intersection angle of 90 degrees, but may intersect at an arbitrary angle.
Further, the present invention is not limited to the above, and the robot arm may be sandwiched and moved in three axis directions.

  Biaxial or triaxial moving means, when thin films as test objects are placed in multiple layers, the uppermost sheet is brought into close contact with the transmission cell opening (Z movement) and measured. After the measurement, the thin film can be used for the purpose of laminating the thin film on the mounting position of the predetermined thin film after measurement.

  In a preferred embodiment of the pinhole detection / transmittance measuring apparatus, the opening / closing means may be an electromagnetic valve or an air valve. An air valve is a valve driven by compressed air. If these valves are employed, the opening / closing operation can be performed instantaneously, and the opening / closing operation can be performed by remote control, making it easy to automate the opening / closing operation.

  Further, in a preferred embodiment of the present pinhole detection / transmittance measuring apparatus, the computing unit has a function of calculating a second derivative value of the pressure sensor measurement value, and the second derivative value is “positive”. The presence or absence of pinholes may be detected after the time point when the value changes from “value” to “zero or negative value”. In this pinhole detection / permeability measuring device, the transmission curve (relationship between time and pressure measurement value) at the time of measurement rises rapidly with a convex curve upward, and then becomes a gentle curve. It becomes a straight line state. The computing unit calculates a second derivative value of the pressure sensor measurement value, and detects the inflection point of the transmission curve by observing the second derivative value. After the inflection point, the presence or absence of pinholes is detected and determined.

According to the present embodiment, it is possible to reduce a risk of erroneously determining that a rapid pressure increase immediately after stopping the evacuation of the transmission cell is caused by the presence of the pinhole.
Here, if the presence or absence of a pinhole is detected immediately after the inflection point, the measurement time can be shortened. However, in order to achieve a reduction in erroneous determination, the determination may be made at an arbitrary time after that time.

Furthermore, in a preferred embodiment of the present pinhole detection / transmittance measuring apparatus, the arithmetic unit has a function of calculating a first derivative value of the pressure sensor measurement value, and the first derivative value is preset. The presence or absence of a pinhole may be detected by comparing with the first reference value.
The pressure rise rate in the permeation cell, that is, the first differential value of the pressure measurement value differs depending on whether or not the pinhole is present in the test object. The gas permeability of a subject with and without a pinhole is measured in advance, and a value between a representative value when there is a pinhole and a representative value when there is no pinhole can be used as the first reference value. The measurement time can be shortened if the subsequent transmittance measurement is stopped by determining whether there is a pinhole.

Further, in a preferred embodiment of the present pinhole detection / transmittance measuring apparatus, the arithmetic unit compares the first derivative value of the pressure sensor measurement value with a second reference value set in advance. You may make it calculate the gas permeability of a to-be-tested object from the time of a differential value becoming below 2nd reference value from the change of the said pressure sensor measured value per fixed time.
The second reference value is set to a value slightly larger than the inclination of the straight line when a typical DUT is in a steady state (a state where the transmission curve becomes a straight line). Thereby, before the gas permeation reaches a steady state, the permeability measurement can be easily performed, so that the time spent for the permeability measurement can be shortened.

  The preferred embodiments of the present invention described above can be combined as much as possible.

  According to the present invention, it is possible to simultaneously detect and determine the presence / absence of a pinhole in a device under test and to measure the transmittance. Moreover, the setting of the test object is facilitated, and the taking out of each thin film laminated in multiple layers can be automated. Furthermore, according to a preferred embodiment of the present invention, since the measurement is performed before the gas permeation amount of the thin film reaches a steady state, pinholes can be detected and presence / absence can be determined in a short time.

  The pinhole detection / transmittance measuring apparatus according to the present invention will be further described below with reference to examples. The dimensions, materials, shapes, relative positions, etc. of the members and parts described in the embodiments of the present invention are not intended to limit the scope of the present invention only to those unless otherwise specified. It is merely an illustrative example.

  FIG. 1 is a block diagram of a pinhole detection / transmittance measuring apparatus according to a first embodiment. In the figure, 1 is a permeation cell assembly including a permeation cell, a pressure sensor, and an open / close valve, 2 is a robot arm that is a moving mechanism for moving the permeation cell assembly in the XYZ directions, 3 is a control arithmetic unit that also serves as an arithmetic unit, 4 is a vacuum pump. The control calculation unit 3 is a computer, and performs control of the robot arm 2, control of the entire apparatus, calculation of the pressure sensor (6) measurement value, calculation of the measurement value, determination, and the like.

  2A and 2B are explanatory views of the transmission cell assembly 1, wherein FIG. 2A is a front view and FIG. 2B is a bottom view. In the figure, 5 is a transmissive cell, the size of the bottom surface is about A4 paper, and the thickness is 1 cm. A pipe 8 and a pipe 9 are connected to the upper part of the permeation cell 5, and the pipe 8 and the pipe 9 are connected to the two distribution manifolds 21 via the open / close valves 7 and 10. The open / close valves 7 and 10 are electromagnetic valves. The manifold 21 is connected to a pipe 23 via an air introduction valve 22.

The tube 23 is connected to the vacuum pump 4 (not shown in FIG. 2) via a flexible joint (not shown). The atmosphere introduction valve 22 is a switching electromagnetic valve, and switches between a conduction state between the atmosphere introduction pipe 24 and the manifold 21 and a conduction state between the pipe 23 and the manifold 21.
A pressure sensor 6 is connected to the tube 8 and the pressure in the permeation cell 5 is measured. The pressure sensor 6 is a vacuum gauge using a piezoelectric element. The measurement value of the pressure sensor 6 is calculated by the control calculation unit 3.
The control calculation unit 3 also performs opening / closing of the opening / closing valves 7, 10 and position control of the air introduction valve 22.

The individual components of the permeable cell assembly 1 (the permeable cell 5, the open / close valves 7, 10 and the pressure sensor 6) are fixed to a single frame (not shown), and a part of the frame is attached to the robot arm 2. It has been. The transmission cell assembly 1 is moved by the robot arm 2 in the three-axis directions of XYZ.
In the figure, 25 is a tray which is a mounting surface of a thin film, and 11 shows a state in which thin films to be measured are stacked and mounted.

  An air valve can also be used as the open / close valves 7 and 10 and the air introduction valve 22.

(B) is a bottom view, showing a surface in contact with the thin film of the transmission cell 5. Reference numeral 13 denotes a transmission surface, and a sintered filter is attached to the surface phase portion, and the inside is hollow. This sintered filter is a member that supports the thin film adsorbed by the permeation cell, and the average pore diameter of the sintered filter is about 50 μm.
The cavity corresponding to the transmission surface 13 is connected to the tube 8 and connected to the pressure sensor 6.

Reference numeral 12 denotes a thin film support portion which is disposed so as to surround the transmission surface 13. A sintered filter similar to that attached to the transmission surface 13 is attached to the surface phase portion of the thin film support portion 12. The inside of the thin film support 12 is a cavity separated from the cavity connected to the transmission surface 13 and is connected to the tube 9.
The transmission surface 13 is a flat surface, and the thin film support portion 12 is also a flat surface. The transmission surface 13, the thin film support 12 and the frame surface 5a of the transmission cell are flush with each other. Further, the transmission surface 13 and the surface of the tray 25 are parallel.

Next, the operation of the pinhole detection / transmittance measurement apparatus will be described.
The transmission cell assembly 1 is moved in the Z-axis direction (downward) and pressed against the thin film 11. The air introduction valve 22 is set to a position where the pipe 23 and the manifold 21 are electrically connected, and the vacuum pump is operated so that the open / close valves 7 and 10 are opened. The inside of the transmission cell 5 is depressurized, and one thin film is adsorbed on the surface of the transmission cell 5. Then, the transmission cell assembly 1 is moved upward. After evacuating the permeation cell 5 for a certain time, the pressure in the permeation cell 5 due to the gas around the permeation cell 5 closing the open / close valve 7 and passing through the thin film is measured by the pressure sensor 6 to measure the permeability. To do. The on-off valve 10 is kept open during the measurement, and the thin film is vacuum-adsorbed to the transmission cell 5 by the thin film support 12.

After the measurement is completed, the transmission cell assembly 1 is moved XY so that the thin film is positioned above the mounting position (not shown) after the measurement is completed, and is further moved downward as necessary. The operation of the vacuum pump 4 is stopped, the atmosphere introduction valve 22 is set to a position where the atmosphere introduction pipe 24 and the manifold 21 are electrically connected, and the opening / closing valve 7 is opened. Since the inside of the transmission cell 5 becomes atmospheric pressure and the adsorption force is lost, the thin film falls.
The above operation is repeated to measure all the laminated test films 11.

Subsequently, the transmittance measurement and the like will be described.
The control calculation unit 3 monitors the pressure measurement value of the pressure sensor 6 and calculates the primary differential value and the secondary differential value. The sampling interval of the pressure measurement value is usually 30 ms (milliseconds) (hereinafter the same) to 300 ms, preferably 50 ms to 200 ms. The primary differential value is calculated from two consecutive measurement values, and two consecutive times. The secondary differential value is calculated from the primary differential value. In this example, the sampling interval of the pressure measurement value was 100 ms.

FIG. 3 is an explanatory diagram of a transmission curve measured by the pinhole detection / transmittance measuring apparatus according to the first embodiment. In FIG. 3, the horizontal axis represents time (T) (unit seconds), and the vertical axis represents the pressure value (P).
An electrolyte membrane for fuel cells (size 32 cm × 24 cm, thickness 130 μm) was used as a thin film to be tested. The time spent for evacuation before measurement is about 20 seconds, and the pressure in the cell at the start of measurement is about 0.00X KPs.

In FIG. 3, 14 is a permeation curve in which the measured value of the pressure sensor 6 is expressed as a time-pressure value, and 16 is a line indicating when the valve 7 is closed. The transmission curve 14 draws an upward convex curve at the initial stage when the valve is closed. This is clearly different from the conventional differential pressure method (JIS K 7126) in that the pressure change appears in a downwardly convex curve state during the unstable period at the beginning of measurement.
Therefore, detection of the presence or absence of a pinhole is started from the time (inflection point) when the secondary differential value of the pressure measurement value changes from “positive value” to “zero or negative value”. The measurement of the presence or absence of a pinhole is performed by comparing the first differential value of the pressure measurement value with a preset first reference value. The first reference value can be determined from the gas permeability of the reference thin film without pinholes.

  Subsequently, after the inflection point, a time point at which the primary differential value is equal to or lower than a preset second reference value is detected, and a pressure increase value for a predetermined time is obtained from the time point, and from this, a thin film as a test object is obtained. The gas permeability is determined.

When measurement is performed by the conventional differential pressure method, the slope of the straight line is obtained after the permeation curve has a constant slope, and the permeability is calculated from the value of the slope. 15 shows the straight line (transmission curve having a constant inclination and its extension line).
Accordingly, the transmittance measured by the pinhole detection / transmittance measuring apparatus according to the present invention is larger than the value measured by the conventional differential pressure method, but the difference is very small. Furthermore, when comparing with the measured value by the conventional differential pressure method, a certain coefficient may be multiplied. In the present invention, it is possible to finish the permeability measurement before the gas permeation becomes steady.

  However, by using the pinhole detection / transmittance measuring apparatus according to the present invention, it is possible to wait until the transmission curve has a certain slope, measure the slope, and calculate the transmittance.

FIG. 4 is an explanatory diagram of a permeation curve represented by a time-pressure value when measuring a thin film having a pinhole. In FIG. 4, the horizontal axis represents time (T) (unit seconds), and the vertical axis represents the pressure value (P).
In the figure, 19 is a line indicating the inflection point. 17 shows a transmission curve of a thin film having a small pinhole, and 18 shows a transmission curve of a thin film having a large pinhole. 14 shows a transmission curve (same as 14 in FIG. 3) of a thin film without a pinhole.

  Furthermore, when a pinhole is detected, it is programmed in the control calculation unit so as to stop the measurement and shift to the measurement of the next thin film.

  In the above example, measurement was performed with the permeation cell open to the atmosphere. However, if you want to measure the gas permeability of a specific gas (eg, helium), specify the permeation cell assembly 1 including the robot arm 2 in a sealed box. A gas atmosphere may be used.

Next, a pinhole detection / transmittance measuring apparatus according to a second embodiment will be described.
FIGS. 5A and 5B are explanatory diagrams of the transmission cell assembly 101 according to the second embodiment, in which FIG. 5A is a front view and FIG. 5B is a bottom view.
In the figure, 45 is a transmission cell, which has a hemispherical shape. A connection pipe 48 connects the permeation cell 45 and the open / close valve 47. A pressure sensor 46 is connected to the connection pipe 48. The pressure sensor 46 can measure the pressure in the permeation cell. The opening / closing valve 47 also serves as an air introduction valve, and switches between a conduction state between the atmosphere introduction pipe 54 and the connection pipe 48 and a conduction state between the pipe 53 and the connection pipe 48.

The tube 53 is connected to the vacuum pump 4 via a flexible joint (not shown).
The individual components (permeation cell 45, on-off valve 47, pressure sensor 46, etc.) of the permeation cell assembly 101 are fixed to a single frame (not shown), and a part of the frame is attached to the robot arm 2. Yes. The transmission cell assembly 101 is moved in the three-axis directions of XYZ by the robot arm 2.
In the figure, reference numeral 56 denotes a tray which is a thin film mounting surface, and reference numeral 41 denotes a state in which thin films to be measured are stacked.

(B) is a bottom view, showing a surface in contact with the thin film of the transmissive cell 45. 43 is a transmission surface, and a net is attached to the surface phase portion, and the inside is hollow. This net is a member that supports the thin film adsorbed in the permeation cell opening, and the average pore diameter of the net is about 50 μm.
The cavity corresponding to the transmission surface 43 is connected to the tube 48.
Reference numeral 55 denotes a lower end surface of the frame of the transmission cell 45, which is made of rubber, flexible synthetic resin, or the like.
The transmission surface 43 is a flat surface. The transmission surface 43 and the lower end surface 55 of the frame are flush with each other. Further, the transmission surface 43 and the surface of the tray 56 are parallel.

  The other components of the pinhole detection / transmittance measuring apparatus, that is, the robot arm 2, which is a moving mechanism, the control calculation unit 3, and the vacuum pump 4, are the same as those in the first embodiment using the transmission cell assembly 1 described above. It is the same.

  Next, the operation of the pinhole detection / transmittance measuring apparatus using the transmission cell assembly 101 will be described.

  The transmission cell assembly 101 is moved in the Z-axis direction (downward) and pressed against the thin film 41. The open / close valve 47 is set to a position where the connecting pipe 48 and the pipe 53 are electrically connected to operate the vacuum pump. The inside of the transmission cell 45 is depressurized, and one thin film is adsorbed on the surface of the transmission cell 45. Then, the transmission cell assembly 101 is moved upward. After the permeation cell 45 is evacuated for a certain period of time, the open / close valve 47 is closed and the pressure increase due to the gas around the permeation cell 45 passing through the thin film is measured by the pressure sensor 46 to measure the permeability.

After the measurement is completed, the transmission cell assembly 101 is moved XY to position the thin film above a mounting position (not shown) after the measurement is completed, and further moved downward as necessary. The operation of the vacuum pump 4 is stopped, and the open / close valve 47 is set to a position where the atmosphere introduction pipe 54 and the connection pipe 48 are electrically connected. Since the inside of the transmission cell 5 becomes atmospheric pressure and the adsorption force is lost, the thin film falls.
The above operation is repeated to measure all the laminated test films 41.

  The transmittance measurement and the like are the same as described in the first embodiment.

The transmission cell 5 according to the first embodiment performs the adsorption of the thin film twice, and is versatile regardless of the material of the thin film, and the lower end surface of the transmission cell is made of aluminum, stainless steel or the like. Can be the same as the cell frame material.
The transmission cell 45 according to the second embodiment performs thin film adsorption only on the transmission surface 43 and is suitable for a thin film made of a soft material. There are advantages such that the internal structure of the permeation cell is simplified and the number of open / close valves is reduced.

  The present invention can be used for pinhole detection and gas permeability detection of all thin films such as plastic films, sheets and processed paper.

1 is a block diagram of a pinhole detection / transmittance measurement apparatus according to a first embodiment. FIG. It is explanatory drawing of the permeation | transmission cell assembly 1. FIG. It is explanatory drawing of the permeation | transmission curve measured with the pinhole detection and the transmittance | permeability measuring apparatus. It is explanatory drawing of the time-pressure value in case there exists a pinhole. It is explanatory drawing of the permeation | transmission cell assembly 101 concerning a 2nd Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101 Permeation | transmission cell assembly 2 Robot arm 3 which is a moving mechanism Control arithmetic part 4 which also serves as a computing unit Vacuum pump 5, 45 Permeation cell 6, 46 Pressure sensor 7, 10, 47 Opening / closing valve 8, 9 Tube

11 and 41 Laminated thin film 12 Thin film support portions 13 and 43 Transmission surface 14 Transmission curve 16 Line 22 indicating opening / closing valve 7 Closed time Air introduction valves 24 and 54 Air introduction pipes 25 and 56 Placement surface of the DUT tray

Claims (5)

A transmission cell having a transmission surface for adsorbing a test object to the transmission surface, a pressure sensor for measuring the pressure in the transmission cell, a vacuum pump for vacuum suction of the transmission cell, and the vacuum for the transmission cell Opening / closing means that closes the inside of the permeation cell after being sucked by the pump, and a measurement value of the pressure sensor are calculated, and the presence or absence of a pinhole in the test object is determined from the calculated value, and the gas of the test object is determined An arithmetic unit for calculating the transmittance is provided.
One sheet at the top of the plurality of test objects placed by changing the distance between the mounting surface of the test object placed in a stacked state and the transmission surface of the transmission cell. the order to vacuum suction, the mounting surface of the test object, the pinhole detection and permeability measurement device provided with a moving means for relatively changing the distance between the transmission surface of the permeation cell. 2. The pinhole detection / transmittance measuring apparatus according to claim 1, wherein the moving means is a moving means for moving the transmission cell up and down. The arithmetic unit has a function of calculating a secondary differential value of the pressure sensor measurement value, and after the time when the secondary differential value changes from “positive value” to “zero or negative value”, The pinhole detection / transmittance measuring apparatus according to claim 1, wherein presence / absence is detected. The arithmetic unit has a function of calculating a primary differential value of the pressure sensor measurement value, compares the primary differential value with a preset first reference value, and detects the presence or absence of a pinhole. The pinhole detection / transmittance measuring device according to any one of claims 1 to 3. The first differential value of the pressure sensor measurement value is compared with a preset second reference value by the arithmetic unit, and the pressure per certain time from the time when the primary differential value becomes equal to or less than the second reference value. 5. The pinhole detection / transmittance measuring apparatus according to claim 1, wherein the gas permeability of the device under test is calculated from changes in sensor measurement values.

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