JP2002243791A - Foreign matter detecting device for insulating sheet and inspection processing method for the sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve quality, safety and reliability of an insulating sheet by detecting conductive foreign matter as an object to be detected while continuously transferring the insulating sheet. SOLUTION: The insulating sheet 1 as an object to be inspected is unwound from an unwinding roll 2, and simultaneously continuously transferred through switch rollers 4, 5, an electrode roller 7 and an invert roller 6 toward a take-up roll 3. The electrode roller 7 and the respective electrode plates 8 are disposed to clamp the sheet 1 from both sides in the direction of thickness, and designated DC voltage is applied between the electrode roller 7 and the electrode plates 8. When conductive foreign matter is caught in the sheet 1 in the course of transfer, current carrying or discharge is caused between the roller electrode 7 and the electrode plates 8, and the occurrence is detected to discriminate whether foreign matter is existent or absent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting foreign matter on an insulating sheet and a method for inspecting the sheet which are preferably used for inspection of shipping of an electrically insulating sheet used as an insulating member of electric and electronic parts. About.

[0002]

2. Description of the Related Art Generally, an electrically insulating sheet for insulating electric and electronic parts is made of, for example, a resin film, a paper material,
It is formed using a nonwoven fabric or a woven sheet, and examples of the material include an inorganic fiber material such as glass excluding carbon fiber, a synthetic resin or a natural fiber material.

[0003] An insulating substrate used for mounting electronic parts and the like is formed by impregnating an electrically insulating sheet made of, for example, glass fiber with an epoxy resin and performing hot pressing or the like.

In such an insulating sheet, for example, when conductive foreign substances such as metal powder, carbon particles, nickel sulfide and the like are mixed in the course of the manufacturing process, the foreign substances ensure sufficient electrical insulation. Therefore, prior to shipment of the product sheet, inspection for foreign matter and the like is performed.

[0005]

However, the foreign matter inspection method according to the prior art often inspects visually for conductive foreign matter mixed in the insulating sheet.

However, as a recent trend, as electronic components become finer and more integrated, for example, 0.1 mm (100 μm)
Unless the following small foreign matter is detected and removed, the function originally required of the insulating sheet cannot be satisfied.

That is, in an insulating sheet having a thickness of 0.1 mm before and after 0.1 mm, for example, a conductive foreign substance having a length of 0.1 mm or less is mixed in a state penetrating in the thickness direction of the sheet. In such a case, it is difficult to secure sufficient electrical insulation as an insulating sheet, and there is a problem that the reliability of an electronic component using the sheet cannot be improved.

In this case, for example, a method of detecting a conductive foreign substance mixed in the sheet by using a metal detector of a search coil system or the like can be considered. However, in the case of such a metal detector, only a foreign substance having a size of about 1 mm at the longest can be detected, and sufficient sensitivity cannot be secured.

As another prior art, a method of detecting a defect in a sheet by image processing using an image sensor, a CCD camera or the like is also known. However, in the method based on image processing, although it is possible to detect ordinary simple dirt or the like, when detecting and processing minute conductive foreign matter from a continuously transported sheet, Actually, a large-scale apparatus is required, and it is difficult to distinguish the non-conductive foreign matter, and the feasibility is poor.

Further, as another conventional technique, for example, use of a high-sensitivity magnetic sensor, an X-ray transmission device, or the like may be considered. However, in the case of a magnetic sensor, it is possible to detect a ferromagnetic foreign substance such as an iron-based material, but it is not possible to detect a weak magnetic foreign substance such as a part of stainless steel, copper, aluminum, and carbon. Have difficulty. Further, there is a case where a large difference occurs in the detection sensitivity depending on the material of the foreign matter, and there is a problem that it is difficult to maintain the detection accuracy with a uniform standard of conductive foreign matter.

Further, when an X-ray transmission apparatus or the like is used, it can be applied to a sheet of a stationary size and of a limited size, but a conductive foreign substance is detected from a continuously running sheet. However, there are problems such as poor practicality and the necessity of large-scale equipment.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to detect a conductive foreign substance to be detected while continuously transferring an insulating sheet. Another object of the present invention is to provide an insulating sheet foreign matter detecting device and a sheet inspection processing method capable of improving the quality safety and reliability of a sheet.

Further, in the present invention, even if the thickness of the electrically insulating sheet to be applied is, for example, 0.1 mm or less, detection of minute foreign matter mixed therein is continuously performed. It is an object of the present invention to provide a device for detecting foreign matter on an insulating sheet and a method of inspecting the sheet, which can eliminate the possibility of conduction in at least the thickness direction.

[0014]

According to a first aspect of the present invention, there is provided an apparatus for detecting foreign matter in an insulating sheet, comprising: a transferring means for continuously transferring a long electric insulating sheet; First and second electrodes located in the middle of the transfer means so as to sandwich the insulating sheet from both sides in the thickness direction, and for detecting conductive foreign matter mixed in the insulating sheet. Voltage applying means for applying a voltage between the first and second electrodes, and detecting means for detecting whether or not current or discharge has occurred between the first and second electrodes due to the application of the voltage by the voltage applying means And the configuration consisting of:

According to this structure, the first and second electrodes can be disposed so as to sandwich the electrically insulating sheet transferred by the transfer means from both sides in the thickness direction. When conductive foreign matter is mixed in the insulating sheet, a voltage applied between the first and second electrodes causes conduction or discharge between the electrodes, and the detecting means detects the foreign matter to detect the foreign matter. The presence or absence can be easily detected.

In this case, the detecting means may be configured to detect the conduction between the electrodes. However, when the configuration is such that only the energization is detected, for example, when a conductive foreign substance is mixed into the insulating sheet in a state where the conductive foreign substance does not slightly contact the electrode, the insulating property is not detected without detecting the foreign substance. The sheet may pass between the electrodes. Then, after inspection of the insulating sheet, there is a possibility that a conduction trouble due to foreign matter may occur. For this reason, it is preferable that the detecting means is configured to detect whether or not discharge has occurred between the electrodes.

Further, a device in which the voltage applying means and the detecting means are integrated may be used, or separate devices may be used. In this case, as an integrated existing device, for example, a spark tester for detecting spark discharge, a partial discharge measuring device for detecting corona discharge, and the like can be given. Further, as the detecting means, a means for detecting any change in current, voltage or electric charge that occurs when energization or discharge occurs between the electrodes, a means for detecting a sound accompanying a spark or the like, a means for detecting an electromagnetic wave, etc. Can also be used. In this case, it is desirable that the detecting means performs the detecting or detecting operation based on whether or not a predetermined threshold value is exceeded as necessary.

When the insulating sheet to be inspected is a sheet having a continuous air space in the thickness direction, such as a nonwoven fabric or cloth (woven fabric), a voltage is applied between the electrodes. Spark discharge is likely to occur due to air breakdown. For this reason, although both a spark tester and a partial discharge measuring machine can be used, it is preferable to use a spark tester having a large discharge amount to be detected. For a material such as a resin film that is unlikely to cause dielectric breakdown unless there is a pinhole, it is preferable to use a partial discharge measuring device having a sensitivity capable of detecting a corona discharge in which only a small amount of current flows.

According to the second aspect of the present invention, the voltage applied by the voltage applying means is set to the first and second values when the conductive foreign matter mixed in the insulating sheet is larger than a predetermined reference value. When current is supplied or discharged between the electrodes, and when the current is smaller than the reference value, the voltage level is set so that no current or discharge occurs.

Accordingly, when the conductive foreign matter mixed into the insulating sheet is larger than the reference value, current flows or discharge occurs between the electrodes, and this can be detected by the detecting means. However, when the conductive foreign matter is smaller than the reference value, the size of the foreign matter is negligibly small, or the foreign matter is mixed in a negligible direction in the insulating sheet. Does not generate electricity or discharge between the electrodes, or has a discharge amount equal to or lower than the detection sensitivity. It is not always necessary to detect such a small foreign substance.

In this case, the set value of the applied voltage may be changed according to the size, shape, etc. of the foreign matter to be detected. Also,
As the size of the foreign substance with respect to the distance between the electrodes (or the thickness T of the insulating sheet) becomes a size and shape closer to the thickness T,
It is possible to improve the detection accuracy when detecting a foreign substance, and it is possible to reduce the possibility of occurrence of a detection error such as missing of a foreign substance or excessive detection of a small foreign substance.

According to a third aspect of the present invention, at least one of the first and second electrodes is electrically connected to the insulating sheet so as to identify where the conductive foreign matter is mixed in the insulating sheet. And a plurality of electrode members provided separately in the width direction of the conductive sheet.

Thus, the detecting means can detect which of the plurality of electrode members corresponds to which one of the electrode members, and whether the energization or the discharge has occurred. Can be identified. The detected location is displayed on a display device such as a display, so that the operator of the inspection work can be notified of the location where the foreign substance is detected.

According to a fourth aspect of the present invention, the plurality of electrode members are constituted by a plurality of electrode plates provided independently of each other with respect to the insulating sheet and uniformly contacting one side surface of the insulating sheet. ing. Thereby, the respective electrode plates arranged separately from each other in the width direction of the insulating sheet can be uniformly contacted with one side surface of the insulating sheet, respectively. Occasionally, the occurrence of energization or discharge between the electrodes can be immediately detected.

In this case, each electrode plate may be provided in a plurality of combinations with a phase shifted in the sheet length direction. As a result, it is possible to prevent the occurrence of a detection leak or the like of foreign matter between, for example, two electrode plates separated in the width direction of the insulating sheet, and to stably determine whether or not foreign matter is mixed over the entire surface of the sheet. Can be inspected.

Insulating sheets produced industrially usually have a width dimension of 1 m or more, and the distance between the first and second electrodes is uniform over a length exceeding 1 m. It is extremely difficult to maintain at intervals. Therefore, one electrode is constituted by a plurality of divided electrode plates, and each of the electrode plates is three-dimensionally movable with respect to the support member, whereby each electrode plate is lightly pressed against the surface of the sheet. And the electrode interval can be made substantially equal to the thickness of the insulating sheet.

The insulating sheet for electric / electronic parts manufactured as a current product is manufactured with a good precision in the order of microns, so that the first means can be obtained by using the above-mentioned means. , The second electrode can ensure a uniform electrode spacing in the sheet width direction.

According to a fifth aspect of the present invention, at least the other of the first and second electrodes is constituted by a roller which rotates in contact with the insulating sheet. This allows
The rotating rollers can ensure that the insulating sheet runs or transports smoothly between the electrodes. Then, by using the rotating roller as an electrode roller, when a conductive foreign matter which is likely to cause a conduction trouble in the thickness direction of the insulating sheet is mixed in the sheet, the conductive foreign matter is transferred between the electrodes. The electrode can be kept in contact with or near a foreign substance in the insulating sheet.

The invention according to claim 6 is configured such that the voltage applied between the first and second electrodes by the voltage applying means is a DC voltage. In this case, the applied voltage can be detected in principle even with an alternating current. However, since the object to be inspected is a continuously running insulating sheet, in the case of an alternating current in which the voltage is constantly fluctuating at the moment when the sheet passes between the electrodes, it may be difficult to detect a foreign substance based on a stable reference. is there. For this reason, by adopting a configuration in which a DC voltage is applied, the detection accuracy of foreign substances can be improved.

Further, according to the invention of claim 7, the first and second electrodes provided in the middle of the transfer means for continuously transferring the long electrically insulative sheet provide a conductive material in the insulative sheet. A foreign matter detection step of detecting whether or not foreign matter has entered, and stopping the transfer of the insulating sheet by the transfer means when the inclusion of the foreign matter is detected, and stopping the insulating sheet at a predetermined inspection position. A sheet stopping step of causing the sheet to be removed, a foreign matter removing step of removing foreign matter mixed in the insulating sheet at the inspection position, and a sheet transfer restart for restarting the transfer of the insulating sheet by the transfer unit after removing the foreign matter. The method employs an insulating sheet inspection processing method comprising the steps of:

Thus, when foreign matter is detected in the foreign matter detecting step, the transfer of the insulating sheet by the transfer means is stopped in the sheet stopping step, and the insulating sheet is stopped at a predetermined inspection position. A removal process can be performed to remove conductive foreign matter mixed in the insulating sheet at the inspection position, for example, by manually looking through a magnifying glass or by using an appropriate jig or the like. After removing the foreign matter, the transfer of the insulating sheet by the transfer means can be restarted, and the inspection process over the entire surface of the sheet can be continued.

It is preferable that such a foreign matter removing process is performed in the entire insulating sheet manufacturing process, for example, in a final inspection process immediately before packing and shipping, whereby conductive foreign materials are mixed. A high quality insulating sheet can be provided to the customer, and the reliability can be improved.

Further, when the worker removes the detected conductive foreign matter, it is easier for the worker to remove the foreign matter in the insulating sheet with higher accuracy. Can be. For this reason, it is preferable that the position of the foreign matter can be specified and detected also in the length direction of the insulating sheet, and this can be displayed on a display or the like. Also,
The method of removing the foreign matter is optional, except for the case where the foreign matter is buried inside, such as a resin film, while looking through the magnifying glass at the specified position and removing it manually or using an appropriate jig Can be done easily.

[0034]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an apparatus for detecting foreign matter on an insulating sheet and a method of inspecting and processing the sheet according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 to FIG. 7 show a first embodiment of the present invention. In the figure, reference numeral 1 denotes an insulating sheet to be inspected (hereinafter referred to as a sheet 1) employed in the present embodiment, and the sheet 1 is a woven fabric using a fiber bundle of an electrically insulating material such as a glass material. Is formed as a long sheet.

That is, as shown in FIG. 3, the sheet 1 is formed by weaving, as warp and weft, fiber bundles 1A, 1A,... . The thickness T of the sheet 1 is, for example, about 0.03 to 0.2 mm, and the width of the sheet 1 is, for example, 1 m (meter) or more.

Reference numeral 2 denotes an unwinding roll on which the sheet 1 is wound. The unwinding roll 2 converts the sheet 1 manufactured as described above by weaving a material such as glass fiber into, for example, an inspection process before shipping. It is used to carry in. The sheet 1 is continuously transported in the direction of arrow A toward the winding roll 3 described later by rotating the unwinding roll 2 with the output from the driver 20 described later.

Reference numeral 3 denotes a take-up roll which constitutes a transfer means of the sheet 1 together with the take-out roll 2;
The sheet 1 unwound from the unwinding roll 2 is continuously wound by being disposed at a position largely separated from the unwinding roll 2 and being rotationally driven by an output from the driver 20.

In addition, between the unwinding roll 2 and the winding roll 3, conversion rollers 4, 5, and 6 for changing the transfer direction of the sheet 1 are disposed together with an electrode roller 7, which will be described later. The rollers 4 to 6 are formed by rollers longer than the width of the sheet 1. The sheet 1 to be transported is transported toward the take-up roll 3 at the positions of the conversion rollers 4 and 5, the electrode roller 7, and the conversion roller 6 while the transport direction is changed by approximately 90 degrees. Things.

Reference numeral 7 denotes a first roller disposed between the conversion rollers 5 and 6.
The electrode roller 7 is composed of a columnar or cylindrical conductive metal roller or the like, and the length of the roller is larger than the width of the sheet 1. The electrode roller 7 forms a ground electrode facing each of the electrode plates 8 described later, and its outer peripheral surface (front surface) uniformly contacts the rear surface of the sheet 1 over a wide area.

The electrode roller 7 has a rotating shaft 7A as shown in FIG. 2, and is rotated about the rotating shaft 7A so that the sheet 1 transferred from the converting roller 5 in a substantially horizontal direction is converted. It is turned downward in the vertical direction to the sixth side and smoothly transported.

8, 8,... Are the sheet 1 together with the electrode roller 7.
Are disposed on both sides in the thickness direction as the second electrodes. These electrode plates 8 are formed of rectangular thin metal plates as shown in FIG. In the width direction of the electrode member.

Further, each electrode plate 8 is compensated for movement independent of the sheet 1 by a connecting member 10 described later,
The sheets 1 are arranged so as to be in uniform contact with the surface which is to be one side face. Then, a voltage is applied between each electrode plate 8 and the electrode roller 7 as described later,
When the conductive foreign matter S is mixed in the sheet 1, an electric flow is generated between the electrode plate 8 and the electrode roller 7 as an energization or discharge phenomenon.

Reference numeral 9 denotes a support bar as a support member for supporting the electrode plate 8 in a hanging state. The support bar 9 is installed above the electrode roller 7 and the electrode plate 8 as shown in FIGS. Approximately parallel to the electrode roller 7 in the width direction of the sheet 1 (left,
(Right direction).

.., Each electrode plate 8 is supported by a support bar 9.
These connectors 10 are formed as a flexible string material made of, for example, an insulating resin material or the like, and constitute a string-shaped hanging member for the electrode plate 8. are doing. The connector 10 holds the electrode plate 8 suspended from the support bar 9 to ensure that the electrode plate 8 moves freely with respect to the sheet 1 in the thickness direction, left, right, and the like. ing.

Reference numeral 11 denotes an adjustment bar provided between the electrode plate 8 and the support bar 9. The adjustment bar 11 movably abuts a middle position of the connecting tool 10, whereby the electrode plate 8 The contact angle is adjusted arbitrarily. Then, by using the connecting tool 10, the adjusting bar 11, and the like,
The electrode plate 8 is uniformly pressed against the surface of the sheet 1 by its own weight, and keeps in smooth contact with the surface of the sheet 1.

Reference numeral 12 denotes a removing station which is located between the electrode roller 7 and the conversion roller 6 and is provided at an intermediate portion of the sheet 1 so as to face the same.
3, the inspection position for removing the foreign matter S mixed in the sheet 1 is arranged. In this case, the light from the illumination device 13 illuminates the sheet 1 brightly, and a part of the light is transmitted to the removal station 12 side.

Then, the worker who has waited in the removal station 12 in advance, under the light radiated from the illumination device 13,
The foreign material S mixed into the sheet 1 is searched while looking through a magnifying glass (not shown) or the like, and an operation of carefully removing the foreign material S from the sheet 1 using a manual operation or an appropriate jig is performed.

Reference numeral 14 denotes a length measuring device provided on the conversion roller 4 on the unwinding roll 2 side. The length measuring device 14 detects the longitudinal position of the sheet 1 by rotating while contacting the conversion roller 4. It constitutes position detecting means. Then, when the foreign matter S is mixed into the sheet 1 by the detector 16 described later, the foreign matter S is mixed at any position (any position in the longitudinal direction) of the sheet 1 based on a detection signal from the length measuring device 14. Can be identified.

Reference numeral 15 denotes a power supply unit as a voltage applying means for applying a voltage between the electrode plate 8 and the electrode roller 7. The power supply unit 15 is connected in parallel to each electrode plate 8 as shown in FIG. As described later, a predetermined constant DC voltage is applied between each electrode plate 8 and each electrode roller 7. The power supply unit 15 includes a voltage adjustment unit (not shown).
Is provided, and the voltage level of the applied voltage is appropriately adjusted by an adjustment signal from the control device 17 described later.

.., Are the power supply section 15 and the respective electrode plates 8.
These detectors 16 are provided independently for each of the electrode plates 8 and are provided between any of the electrode plates 8 and the electrode rollers 7 as described later. This is to detect whether energization or discharge has occurred. Then, when such energization or discharge occurs, an electric flow occurs before and after the detector 16, and the detector 16 detects this, and outputs a detection signal to the control device 17.

Reference numeral 17 denotes a control device constituted by a microcomputer or the like. The input side of the control device 17 is connected to the length measuring device 14, each detector 16 and the start switch 18, and the output side is a power supply unit 15. , A display, such as a display, and a driver 20. Then, the control device 17 stores the sheet inspection processing procedure and the like as shown in FIG. 7 in its storage circuit (not shown), and
The foreign substance detection processing and the foreign substance removal processing are performed.

When the display 19 detects that the foreign matter S is mixed in the sheet 1, the display 19 indicates the mixing position of the foreign matter S based on the signals from the length measuring device 14 and the detectors 16 based on the signals. 1 is specified and displayed in the longitudinal direction and the width direction. In this case, the display 19 is arranged at a position near the removal station 12.

The driver 20 constitutes a driving circuit for driving an electric motor (not shown) provided on the unwinding roll 2 and the winding roll 3, and a driving signal is outputted from the control device 17. Then, the unwinding roll 2 and the winding roll 3 are driven to rotate substantially in synchronization with each other, and when the output of the drive signal is stopped, the unwinding roll 2 and the winding roll 3 are stopped almost simultaneously.

The device for detecting foreign matter on an insulating sheet according to the present embodiment has the above-described configuration. Next, an inspection processing method including a foreign matter detection process and a foreign matter removal process for the sheet 1 will be described with reference to FIG. It will be described with reference to FIG.

First, when the processing operation by the control device 17 is started by turning on the start switch 18, step 1 is executed.
By outputting a drive signal to the driver 20, the unwinding roll 2 and the winding roll 3 are driven to rotate substantially in synchronization. Then, the unwinding roll 2 and the winding roll 3 rotate with respect to each other, so that the long sheet 1 is moved in the direction indicated by the arrow A in FIG.
Transfer continuously in the direction.

At this time, voltage application from the power supply unit 15 is started, and the power supply unit 15 and the plurality of electrode plates 8, 8,
Are individually monitored by using the detectors 16 provided in parallel with each other between the electrode plates 8 and the electrode rollers 7 as to whether or not electric current or discharge occurs.

Then, in step 2, it is determined whether or not the conductive foreign matter S has been detected based on the signal from the detector 16 (foreign matter detecting step).
Repeat the subsequent processing. Further, if “YES” is determined in step 2, which means that the conductive foreign matter S is present in the sheet 1, the process proceeds to step 3 and subsequent steps.

In this case, the electrode plate 8 opposes the sheet 1 having a thickness T between the electrode rollers 7 so as to sandwich the sheet 1 as shown in FIGS. Is transported so as to run continuously between Then, as illustrated in FIG. 4, when a conductive foreign matter S enters the sheet 1 and the foreign matter S penetrates through the sheet 1 in the thickness direction, the corresponding electrode plate 8 and the electrode roller 7 Electric current or discharge occurs between the two.

That is, as shown in FIG. 4, the applied voltage of the power supply section 15 shown in FIG. 6 is such that the size of the foreign matter S in the direction of the thickness T of the sheet 1 is equal to the reference value T 1 (for example, 4 / 5
The voltage level is set to a predetermined voltage level (for example, about 400 V) so that current or discharge occurs between the electrode plate 8 and the electrode roller 7 when the voltage exceeds the predetermined value.

The magnitude of the voltage applied by the power supply unit 15 can be changed according to, for example, the thickness T of the sheet 1 or the like, and may be a voltage value lower than 400 V, or vice versa.
The voltage value may be set to a value higher than 0 V, which is determined in relation to the reference value T1.

When the conductive foreign matter S mixed into the sheet 1 is smaller than the reference value T 1 in the direction of the thickness T of the sheet 1 as shown in FIG.
There is no energization or discharge between the electrode and the electrode roller 7. Moreover, even if it is generated, it is a very small amount of discharge and is not detected. Therefore, the detector 16 determines that no foreign matter is present in the sheet 1 and outputs a non-detection signal to the control device 1.
7 is output.

On the other hand, as shown in FIG. 4, when a conductive foreign matter S exists in the sheet 1 in the thickness direction and current or discharge occurs between the electrode plate 8 and the electrode roller 7,
The corresponding detector 16 outputs a detection signal to the control device 17 assuming that the foreign matter S is present at a position corresponding to the electrode plate 8 of the sheet 1. As a result, "YES" is determined in the step 2, and the process proceeds to the next step 3.

In step 3, the position of the sheet 1 containing the foreign matter S is specified and displayed on the display 19. In this case, the position of the foreign matter S in the longitudinal direction of the sheet 1 is determined by a signal from the length measuring device 14 in consideration of, for example, the distance between the electrode plate 8 and the length measuring device 14.

The position of the foreign matter S in the width direction of the sheet 1 is determined by which of the electrode plates 8, 8,... Arranged in parallel in the width direction of the sheet 1 with a gap therebetween. Each detector 16 individually detects whether the energization or the discharge has occurred in the electrode plate 8, thereby detecting each of the detectors 1.
6 is specified.

Next, in step 4, the output of the drive signal to the driver 20 is temporarily stopped at the stage when the foreign matter S is detected, and the transfer of the sheet 1 by the unwinding roll 2 and the winding roll 3 is stopped. Then, at the stage where the foreign material S mixing position in the longitudinal direction of the sheet 1 is identified, the transfer of the sheet 1 is restarted manually or automatically.

Then, the sheet 1 is gradually transferred until the foreign matter mixing position of the sheet 1 becomes a position facing the removing station 12 in FIG. 1, and the sheet 1 is stopped at the position of the removing station 12 (sheet stopping step). ).

Next, in step 5, the worker, who has been waiting in the removal station 12 in advance, determines the mixing position of the foreign matter S from the display on the display 19, and enters the sheet 1 under the irradiation light from the illumination device 13. The contaminant S is searched for using a magnifying glass or the like. Then, when the corresponding foreign matter S is found, the foreign matter S is removed from the sheet 1 manually or by using an appropriate jig.
Is carried out so as to be carefully removed from the substrate (foreign matter removing step).

After the foreign matter S has been removed, the start-up switch 18 is turned on again in the next step 6 to rotate the unwinding roll 2 and the winding roll 3 so that the sheet 1 is moved in the direction indicated by the arrow in FIG. The sheet is transferred in the direction A (sheet transfer restarting step). Then, the process returns in step 7 and repeats the processing in step 1 and thereafter. Thereby, the sheet 1 in which the conductive foreign matter S is not mixed can be shipped as an insulating sheet member such as an electronic component.

Thus, according to the present embodiment, the electrode roller 7 and each electrode plate 8 are moved in the thickness direction with respect to the sheet 1 continuously transferred between the unwinding roll 2 and the winding roll 3. It is arranged so as to be sandwiched from both sides, and a predetermined DC voltage is applied between these electrode rollers 7 and the respective electrode plates 8.

For this reason, when the conductive foreign matter S is mixed in the sheet 1 during the transfer (running), a current or a discharge is generated between the roller electrode 7 and the electrode plate 8, and this is detected by a plurality of detections. Detector 16, one of detectors 16, 16,...
, The presence or absence of the foreign matter S can be easily detected.

In this case, the detector 16 detects that the foreign matter S in the sheet 1 penetrates in the direction of the thickness T,
When the contact is made, the foreign matter S can be detected as a current between the electrodes 7 and 8. However, even if the conductive foreign matter S is mixed in the sheet 1 in a state where the conductive foreign matter S does not directly contact the electrode roller 7 and the electrode plate 8,
After the inspection, there is a possibility that energization trouble due to foreign matter S may occur at a customer or the like.

Therefore, when the DC voltage applied from the power supply unit 15 is larger than the predetermined reference value T 1, the conductive foreign matter S mixed in the sheet 1 is energized or discharged between the electrodes 7 and 8. Occurs, and when it is smaller than the reference value T1, the voltage level is set to a level at which no energization or discharge occurs.

As a result, the detector 16 can detect the foreign matter S mixed in the sheet 1 according to the result of comparison with the reference value T 1, that is, whether or not electricity or discharge occurs between the electrodes 7 and 8. The conductive foreign matter S is equal to the reference value T1.
If the size of the foreign matter S is smaller than negligible, it can be determined that the size of the foreign matter S is negligibly small or that the foreign matter S is mixed in the sheet 1 in a negligible direction. Does not occur, and can be shipped as a sheet 1 having high insulating properties.

Are provided so as to be separated from each other in the width direction of the sheet 1 and extend in parallel with the electrode roller 7, and correspond to the respective electrode plates 8. Are arranged in parallel with the power supply unit 15 so that each of the detectors 16 can detect which of the electrode plates 8 corresponds to the energized or discharged state, Foreign matter S is mixed in any position in the width direction,
It can be identified whether it exists.

Further, in the longitudinal direction of the sheet 1, the position where the foreign matter S is mixed can be automatically detected by using the length measuring device 14. The detected location of the foreign matter S is displayed on a display 19 such as a display to notify an operator (operator) who actually performs the work of removing the foreign matter S at the position of the removal station 12. Can be.

The electrode plate 8 is suspended from the support bar 9 by using a connecting member 10 such as a flexible string, and is brought into uniform contact with the surface side of the sheet 1 by its own weight. 1, it is possible to guarantee that the respective electrode plates 8 arranged separately from each other in the width direction independently and uniformly contact the surface of the sheet 1, and that the conductive foreign matter S contacts or approaches the electrode plate 8. Occasionally, it is possible to immediately detect the occurrence of energization or discharge between the electrodes 7 and 8.

On the other hand, the electrode roller 7 facing each electrode plate 8
Is in contact with the back side of the continuously running seat 1, and the seat 1
The sheet 1 to be inspected can be smoothly moved or transferred between the electrodes 7 and 8 because the sheet 1 is rotated following the transfer of the sheet. Further, the power supply unit 15 can detect the foreign matter S at a relatively low voltage by applying a DC voltage, and can improve the detection accuracy.

Therefore, according to the present embodiment, the conductive foreign matter S to be detected can be detected while the sheet 1 is continuously transferred, and at least the conduction trouble in the thickness direction of the sheet 1 can be detected. Can be satisfactorily prevented from occurring. As a result, the sheet 1 for ensuring insulation of electronic components and the like can be shipped with quality and safety secured, and the reliability thereof can be improved.

Further, even if the electrically insulating sheet 1 to be applied has a thickness of, for example, 0.1 mm or less, a minute foreign matter S having a particle diameter of 0.1 mm or less mixed therein is continuously removed. , And the processing operation can be performed smoothly, so that the inspection process and the like before the sheet 1 is shipped can be made more efficient,
Overall workability can be reliably improved.

Next, FIGS. 8 and 9 show a second embodiment of the present invention. The feature of this embodiment is that each electrode plate and electrode roller are shifted in phase in the longitudinal direction of the insulating sheet. The configuration is such that a plurality of staggered combinations are provided. In this embodiment, the same components as those in the above-described first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the figure, reference numerals 21 and 22 denote two sets of electrode rollers which are disposed between the conversion rollers 5 and 6 so as to be spaced apart in the longitudinal direction of the sheet 1 and constitute a first electrode.
Although the reference numerals 1 and 22 have the same configuration as the electrode roller 7 described in the first embodiment, another conversion roller 23 is additionally provided between the electrode rollers 21 and 22.

The electrode roller 21 is connected to the conversion roller 5,
23, and is rotated about a rotation shaft 21A. Thus, the electrode roller 21 converts the sheet 1 transferred from the conversion roller 5 in a substantially horizontal direction into the conversion roller 2.
Turns downward to the 3 side and transports smoothly.

The electrode roller 22 is connected to the conversion roller 2.
It is arranged between 3 and 6, and is rotated about the rotation shaft 22A. As a result, the electrode roller 22 becomes the conversion roller 23
The sheet 1 transported upward from the side is converted by the conversion roller 6
It turns downward and moves smoothly.

Reference numerals 24, 24,... Denote electrode plates serving as second electrodes disposed so as to sandwich the sheet 1 from both sides in the thickness direction together with the electrode rollers 21. These electrode plates 24 are used in the first embodiment. The electrode members 8 are formed in the same manner as the electrode plate 8 described in the embodiment, and each constitute an electrode member that is disposed apart from each other in the width direction of the sheet 1.

Reference numerals 25, 25,... Denote electrode plates serving as second electrodes disposed so as to sandwich the sheet 1 from both sides in the thickness direction together with the electrode roller 22. These electrode plates 25 are the same as the electrode plate 24. Is formed. However, as shown in FIG. 9, these electrode plates 24 and 25 are arranged at positions that are alternately arranged in the width direction of the sheet 1.

As a result, when the conductive foreign matter S is mixed in the sheet 1 at a position between the respective electrode plates 24, each of the electrode plates 25 located on the downstream side thereof (the corresponding detector 16) makes it possible to detect foreign matter S, and other foreign matter S can be detected by each of the electrode plates 24 on the upstream side.

Reference numerals 26 and 27 denote support bars serving as support members for supporting the electrode plates 24 and 25 in a hanging state. The support bars 26 and 27 are similar to the support bar 9 described in the first embodiment. It is configured. The support bar 26 is installed above the electrode roller 21 and the electrode plate 24, and the support bar 27 is installed above the electrode roller 22 and the electrode plate 25.

Adjustment bars 28 and 29 are provided between the respective electrode plates 24 and 25 and the support bars 26 and 27. The adjustment bars 28 and 29 are the adjustment bars 11 described in the first embodiment.
And movably abut the intermediate position of each connecting member 10 so that the electrode plates 24, 25
The contact angle is adjusted arbitrarily.

Thus, in the present embodiment having the above-described structure, substantially the same operation and effect as those of the first embodiment can be obtained. However, in this case, the combination of the two sets of electrode rollers 21 and 22 and the respective electrode plates 24 and 25 is
It is configured to be arranged at an intermediate position of the seat 1 so as to be out of phase with each other.

Thus, it is possible to prevent the detection leakage of the foreign matter S between the respective electrode plates 24 or 25 separated in the width direction of the sheet 1 and to check whether the foreign matter S is mixed over the entire surface of the sheet 1. It can be checked with a high degree of accuracy.

In the first embodiment, each electrode plate 8 divided in the width direction of the sheet 1 is hung from the support bar 9 by a connecting member 10 made of a flexible cord. Although it has been described that the electrode plate 8 is lightly pressed against the surface side of the sheet 1 by its own weight, the present invention is not limited to this. For example, the electrode plate 8 is formed using a universal joint (universal joint) made of metal or plastic. It may be configured to be individually connected to the support bar 9.

Also in this case, the electrode plate 8 can be movably supported three-dimensionally, and the electrode plate 8 can be kept in uniform contact with the surface of the sheet 1 by using a biasing means such as a spring. Can be held. This is the same in the second embodiment.

In the first embodiment, the case where the flat electrode plate 8 is used has been described as an example. However, the present invention is not limited to this. For example, a round rod made of a conductive material may be used. Alternatively, the second electrode may be configured using a plurality of electrode members including a free roller or the like.

As described above, the first and second electrodes may be of various types, such as a circular roller, a round bar, a flat plate, and the like.
It is necessary to have a sufficiently smooth electrode surface as compared to these foreign substances. In this case, it is possible to guarantee that stable conduction or discharge occurs between the electrodes when a conductive foreign object approaches.

In the first embodiment, as shown in FIG. 6, the power supply unit 15, the detectors 16, and the control device 1
Although a case has been described as an example in which 7 and the like are configured separately, the present invention is not limited to this, and for example, an apparatus in which voltage applying means and detecting means are integrated may be used.
In this case, as an integrated existing device, for example, a spark tester for detecting spark discharge, a partial discharge measuring device for detecting corona discharge, and the like can be given.

The detecting means detects any change in current, voltage or electric charge which occurs when electricity is supplied or discharged between the electrodes, a means for detecting a sound accompanying a spark or the like, and a means for detecting an electromagnetic wave. What is done can also be used. In this case, it is desirable that the detecting means performs the detecting or detecting operation based on whether or not a predetermined threshold value is exceeded as necessary.

When the insulating sheet to be inspected is a sheet having a continuous air space in the thickness direction, such as a nonwoven fabric or cloth (woven fabric), a voltage is applied between the electrodes. Spark discharge is likely to occur due to air breakdown. For this reason, although both a spark tester and a partial discharge measuring machine can be used, it is preferable to use a spark tester.

For a material such as a resin film which is unlikely to cause dielectric breakdown unless there is a pinhole, it is preferable to use a partial discharge measuring device having a sensitivity capable of detecting a corona discharge in which only a small amount of current flows. The above points are the same as in the second embodiment.

[0100]

As described above in detail, according to the first aspect of the present invention, the first and second electrodes are provided on both sides in the thickness direction with respect to the electrically insulating sheet continuously transferred by the transfer means. When conductive foreign matter is mixed in the insulating sheet in the middle of the transfer, current or discharge is generated between the electrodes by the voltage applied between the first and second electrodes,
Since the detection means detects this, the conductive foreign matter to be detected can be easily detected from the inside of the sheet while continuously transporting the insulating sheet. Etc. can be reliably prevented.

Therefore, the insulating sheet used for an electronic component or the like can be shipped with the quality and safety secured, and the reliability can be improved. Further, even if the insulating sheet to be applied has a thickness of, for example, 0.1 mm or less, minute foreign matter mixed therein can be continuously detected, and the processing operation can be performed smoothly.

Further, according to the second aspect of the present invention, when the conductive foreign matter mixed into the insulating sheet is larger than the reference value, current flows or discharge occurs between the electrodes, and this can be detected by the detecting means. When the conductive foreign matter is smaller than the reference value, the size of the foreign matter is determined to be negligibly small, and the work of detecting the foreign matter can be performed smoothly. As a result, as the size of the foreign matter becomes a size and shape closer to the thickness of the insulating sheet, the detection accuracy when detecting the foreign matter can be increased, and the foreign matter may be overlooked or the small foreign matter may be excessively removed. It is possible to reduce the occurrence of a detection error such as the detection of an error.

According to the third aspect of the present invention, at least one of the first and second electrodes is constituted by a plurality of electrode members provided separately in the width direction of the insulating sheet. Therefore, it is possible to detect whether energization or discharge has occurred at a position corresponding to any of the plurality of electrode members, and it is possible to identify at which position of the insulating sheet foreign matter is mixed or present. .

According to the fourth aspect of the present invention, by disposing a plurality of electrode plates separated from each other in the width direction of the insulating sheet, each electrode plate can be uniformly disposed on one side surface of the insulating sheet. It is possible to make a contact, and it is possible to stably detect an energization or a discharge when a conductive foreign substance contacts or approaches the electrode plate.

According to the fifth aspect of the present invention, at least the other of the first and second electrodes is constituted by a roller which rotates in contact with the insulating sheet. It can be ensured that the conductive sheet is smoothly moved or transferred between the electrodes. When conductive foreign matter that is likely to cause conduction trouble in the thickness direction of the insulating sheet is mixed in the sheet, the electrode roller is brought into contact with the foreign matter in the insulating sheet or in a state close thereto. Can be held.

According to the sixth aspect of the present invention, the voltage applying means is configured to apply a DC voltage between the first and second electrodes. It is possible to stably detect a foreign substance in a continuously running sheet, and to improve the detection accuracy.

[0107] Further, the invention according to claim 7 is characterized in that:
When a foreign substance in the sheet is detected in the foreign substance detection step using the second electrode, the transfer of the insulating sheet by the transfer means is stopped in the sheet stopping step, and the insulating sheet is stopped at a predetermined inspection position. At the same time, a removal process can be performed to remove conductive foreign matter mixed in the insulating sheet at this inspection position, for example, by manually looking through a magnifying glass or by using an appropriate jig. After removing the foreign matter, the transfer of the insulating sheet by the transfer means can be restarted, and the inspection process over the entire surface of the sheet can be continued. This makes it possible to provide a customer with a high-quality insulating sheet in which conductive foreign matter is not mixed, thereby improving reliability.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing a sheet foreign matter detection device according to a first embodiment of the present invention.

FIG. 2 shows an electrode roller and each electrode plate, etc., as indicated by arrows II in FIG.
It is the top view seen from the -II direction.

FIG. 3 is an explanatory diagram showing a woven fabric structure in which the sheet in FIG. 1 is enlarged.

FIG. 4 is an enlarged sectional view showing a state where the sheet in FIG. 1 is sandwiched between an electrode roller and an electrode plate.

FIG. 5 is a cross-sectional view of a principal part substantially similar to FIG. 4, showing a case where foreign matter mixed into a sheet is negligibly small.

FIG. 6 is a circuit diagram of the foreign object detection device according to the first embodiment.

FIG. 7 is a flowchart illustrating a procedure of a sheet inspection process according to the first embodiment.

FIG. 8 is an overall configuration diagram illustrating a sheet foreign matter detection device according to a second embodiment.

FIG. 9 shows an electrode roller and each electrode plate, etc., as indicated by arrows IX in FIG.
It is the top view seen from the -IX direction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating sheet 2 Unwinding roll (transfer means) 3 Take-up roll (transfer means) 4,5,6,23 Conversion roller 7,21,22 Electrode roller (first electrode) 8,24,25 Electrode plate ( 2nd electrode) 10 Connector 12 Removal station (Inspection position) 13 Illumination device 14 Length measuring device 15 Power supply unit (Voltage applying unit) 16 Detector (Detecting unit) 17 Control device 18 Start switch 19 Display 20 Driver (Drive) Equipment) S Conductive foreign matter

Claims (7)

[Claims] 1. A transfer means for continuously transferring a long electric insulating sheet, and a first and a first means arranged in the middle of the transfer means so as to sandwich the insulating sheet from both sides in the thickness direction. A second electrode; a voltage application unit for applying a voltage between the first and second electrodes to detect a conductive foreign substance mixed in the insulating sheet; A foreign matter detecting device for an insulating sheet, comprising: detecting means for detecting whether or not current or discharge has occurred between the first and second electrodes. 2. The method according to claim 1, wherein the voltage applied by the voltage applying means is such that when conductive foreign matter mixed into the insulating sheet is larger than a predetermined reference value, a current is applied between the first and second electrodes. The foreign matter detection device for an insulating sheet according to claim 1, wherein a voltage level is set such that a discharge occurs and a current or a discharge does not occur when the voltage is smaller than the reference value. 3. The insulating sheet according to claim 1, wherein at least one of the first and second electrodes is arranged in a width direction of the insulating sheet to identify a position of the insulating sheet in which the conductive foreign matter is mixed. 3. The foreign matter detecting device for an insulating sheet according to claim 1, wherein the device comprises a plurality of electrode members separately provided. 4. The plurality of electrode members are constituted by a plurality of electrode plates provided independently of each other with respect to the insulating sheet and uniformly contacting one side surface of the insulating sheet. 3. The foreign matter detection device for an insulating sheet according to claim 1. 5. The insulating sheet according to claim 3, wherein at least the other of the first and second electrodes is formed of a roller that rotates in contact with the insulating sheet. Detection device. 6. A voltage applied between the first and second electrodes by the voltage applying means is a DC voltage.
6. The foreign matter detecting device for an insulating sheet according to 3, 4, or 5. 7. Whether conductive foreign matter is mixed in the insulating sheet by the first and second electrodes provided in the middle of a transfer means for continuously transferring a long electric insulating sheet. A foreign matter detecting step of detecting whether or not the foreign matter has been mixed, and a sheet stopping step of stopping the transfer of the insulating sheet by the transfer means and stopping the insulating sheet at a predetermined inspection position when the foreign matter is mixed, An insulating sheet comprising: a foreign matter removing step of removing foreign matter mixed in the insulating sheet at the inspection position; and a sheet transfer restarting step of restarting the transfer of the insulating sheet by the transfer means after removing the foreign matter. Inspection processing method.