JP2014072251A - Clogging inspection device for porous material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a clogging inspection device for porous material capable of inspecting clogging of a porous material without requiring large-scale preparations and measuring partial clogging of a porous material.SOLUTION: A clogging inspection device for porous material 1 includes a measuring head 2, an air supply passage 3, a first regulator 4 and a second regulator 5. The measuring head 2 has an air jet nozzle opened at the other end 2b covered with an elastic member 6. The air supply passage 3 communicates with an air jet nozzle 7 at one end and an air supply source 8 at the other end. The air regulators 4, 5 are arranged at the air supply passage 3 and adjust the pressure of the compressed air jetted from the air jet nozzle 7 of the measuring head 2 to a predetermined value in cooperation with each other. The second regulator 5 includes a pressure gauge 9. The pressure gauge 9 is arranged between the measuring head 2 and the second regulator 5. The pressure gauge 9 shows the pressure of the compressed air jetted from the air jet nozzle 7.

Description

  The present invention relates to an inspection apparatus for measuring clogging of a porous material, and more particularly to an inspection apparatus for detecting a clogging state of ceramics used in a chuck table for sucking and holding a workpiece such as a dicing apparatus.

  In a processing apparatus such as a dicing apparatus, a work piece is formed by applying a negative pressure to the porous ceramic placed on the upper surface (holding surface) of the work piece using a chuck table in which the porous ceramic is surrounded by a frame. It is known to process in a state of being held by suction. Fixing by suction has advantages that it can be attached and detached freely, and that high-precision processing can be realized without vibration of the workpiece during processing by adjusting suction force and improving airtightness.

  However, if processing scraps or the like of the workpiece generated during processing flow into the porous ceramics and generate a so-called clogged state, the suction force decreases, and the workpiece vibrates during processing. Therefore, the processing result is affected. Therefore, in order to inspect whether clogging of the porous ceramic has occurred, the entire upper surface of the porous ceramic is covered with a sheet or the like while the porous ceramic is bonded to the frame to form a chuck table. How much the sheet is sucked by applying a negative pressure to the cover chuck table (for example, refer to Patent Document 1), means such as measuring and determining the pressure and flow rate of the suction passage that can act on the chuck table (for example, Patent Document 2) has been devised.

Japanese Patent Laid-Open No. 05-23941 JP 2007-229889 A

  However, in the means shown in Patent Document 1 and Patent Document 2, it is necessary to form a chuck table, and it is necessary to prepare a component (ejector or the like) as a suction source in order to apply a suction force. There was a problem that partial clogging of the porous material could not be measured.

  The present invention has been made in view of the above-mentioned problems, and its purpose is to allow inspection of clogging of a porous material without requiring extensive preparation, and partial clogging of the porous material. It is an object of the present invention to provide a clogging inspection device for a porous material capable of measuring the above.

  In order to solve the above-described problems and achieve the object, a porous material clogging inspection apparatus according to the present invention is a clogging inspection apparatus for inspecting clogging of a porous material, and is an elastic material. A measurement head having an air outlet opening in a part of a lower surface covered with a member, an air supply path having an end communicating with the air ejection opening of the measurement head, and the other end communicating with an air supply source, and the air supply path And a regulator that adjusts the pressure of the air ejected from the air ejection port of the measurement head to a predetermined value, and the air that is disposed between the measurement head and the regulator and is ejected from the air ejection port. A pressure gauge indicating the pressure of the air, and after adjusting the pressure of the air to be ejected to the predetermined value, the air is ejected while pressing the lower surface of the measuring head to a desired position of the porous material. Measurement is performed by measuring the pressure. And, the pressure of the air measured by the porous material of the test object, characterized in that it utilized to determine clogged.

  According to the clogging inspection apparatus of the present invention, the clogging of the porous material is measured based on the pressure of the air ejected from the air outlet of the measuring head which is brought into close contact with the desired position of the porous material by the elastic member. . For this reason, it is not necessary to install a pressure gauge in a vacuum suction path or the like of a processing device such as a cutting device, and it is possible to easily measure clogging without preparing a suction source (cutting device). Air blow piping provided in the processing equipment such as can be used as an air supply source, so measurement can be easily performed). Further, since the clogging of the porous material is measured based on the pressure of the air ejected from the air ejection port of the measuring head, the clogging of the porous material can be measured without forming a chuck table. Therefore, it is possible to inspect the clogging of the porous material without requiring extensive preparation.

  In addition, since the air ejection port is provided on a part of the lower surface of the measurement head to reduce the diameter of the air ejection port, there is also an effect that the partial clogging state of the porous material can be measured. Therefore, partial clogging of the porous material can also be measured.

  Further, since the air pressure is adjusted by the regulator, the increase value of the pressure of the compressed air from the predetermined value increases in the clogged state. Because of this, a subtle blockage can be found. In addition, since the pressure of the compressed air when the atmosphere is released can always be measured by the regulator as a constant pressure, it is possible to make a determination based on the absolute value of the pressure of the compressed air. Therefore, it is not necessary to compare with a clogged sample. Therefore, since the clogged sample is not required, the clogging of the porous material can be inspected without requiring a large preparation.

FIG. 1 is an explanatory diagram illustrating a configuration of the inspection apparatus according to the embodiment. FIG. 2 is a perspective view showing a schematic configuration of a measuring head of the inspection apparatus shown in FIG. FIG. 3 is an explanatory diagram showing a clogging inspection of the inspection apparatus shown in FIG. FIG. 4 is a diagram showing a change in pressure measured by the pressure gauge of the inspection apparatus shown in FIG.

  DESCRIPTION OF EMBODIMENTS Embodiments (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. The constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the structures described below can be combined as appropriate. Various omissions, substitutions, or changes in the configuration can be made without departing from the scope of the present invention.

  A porous material clogging inspection apparatus (hereinafter simply referred to as an inspection apparatus) according to the present embodiment will be described with reference to FIGS. 1 is an explanatory diagram illustrating a configuration of an inspection apparatus according to the embodiment, FIG. 2 is a perspective view illustrating a schematic configuration of a measurement head of the inspection apparatus illustrated in FIG. 1, and FIG. FIG. 4 is an explanatory view showing a clogging inspection of the inspection apparatus shown in FIG. 1, and FIG. 4 is a view showing a change in pressure measured by the pressure gauge of the inspection apparatus shown in FIG.

  The inspection apparatus 1 according to the present embodiment is an inspection apparatus that inspects clogging of a porous portion 11 (corresponding to a porous material) such as a chuck table 10 (shown in FIG. 1).

  In this embodiment, the chuck table 10 as an inspection target to be inspected for clogging by the inspection apparatus 1 according to the present embodiment is, for example, a disk-shaped semiconductor wafer whose base material is silicon, sapphire, gallium, or the like. It is installed in a processing device such as a cutting device for cutting a workpiece such as an optical device wafer or the like, a grinding device for grinding a workpiece, or a polishing device for polishing a workpiece, and holds the workpiece. .

  The chuck table 10 has a disk shape in which a porous portion 11 constituting a surface is formed of a porous material such as porous ceramics. The chuck table 10 is installed in the above-described processing apparatus, is connected to a vacuum suction source (not shown) via a vacuum suction path (not shown), and sucks a workpiece placed on the surface 11 a of the porous portion 11. It is to hold. In the porous portion 11 of the chuck table 10, contamination generated by processing such as cutting, grinding, and polishing enters due to the suction force from the vacuum suction source, and a part or the whole is clogged, and the workpiece is sufficiently It may become impossible to suck. If the chuck table 10 cannot sufficiently suck the workpiece, the workpiece moves during machining such as cutting, grinding, and polishing, resulting in machining defects such as chipping on the back surface of the workpiece. There is.

  The roughness of the porous portion 11, that is, the count, is about 280 to 320 for the chuck table 10 installed in the cutting apparatus, and about 1000 for the chuck table 10 installed in the grinding apparatus.

  As shown in FIG. 1, the inspection apparatus 1 according to the present embodiment includes a measurement head 2, an air supply path 3, a first regulator 4 (corresponding to a regulator), and a second regulator 5 (corresponding to a regulator). Prepare. As shown in FIG. 2, the measuring head 2 is provided with a space on the inner side and is formed in a cylindrical shape. An air supply path 3 is connected to one end 2 a (corresponding to the upper surface) of the measuring head 2. The other end 2b (corresponding to the lower surface) of the measuring head 2 is covered with an elastic member 6, and an air outlet 7 is opened at a part of the other end 2b. The air outlet 7 is formed in a circular shape having a diameter of 1 mm or more and 5 mm or less.

  The reason why the diameter of the air outlet 7 is 1 mm or more is that if the diameter of the air outlet 7 is less than 1 mm, the processing accuracy of the air outlet 7 and the like and the influence of foreign matter on the surface 11 a of the porous portion 11 of the chuck table 10 are affected. This is because the pressure of compressed air at the time of measurement varies due to the above, and it is impossible to accurately measure whether or not the pressure is clogged. In addition, the reason that the diameter of the air outlet 7 is 5 mm or less is that the size of the chip divided by the machining of the workpiece is about 5 mm, so that the diameter of the air outlet 7 exceeds 5 mm, Even if there is a clogged part around a defective chip (which means a chip with a defective processing such as chipping on the back surface), the compressed air ejected from the air outlet 7 is not clogged. This is because the clogged state cannot be measured. In other words, the size of the air jet port 7 indicates the minimum size of the clogging that can be detected.

  The elastic member 6 is made of a resin having elasticity such as rubber, is formed in a thick disk shape, and covers the other end 2 b of the measuring head 2. The elastic member 6 is provided with a communication hole 6 a that communicates with the air outlet 7. The communication hole 6 a is formed in the same size as the air jet port 7.

  The air supply path 3 is a pipe through which compressed air (corresponding to air, which is a pressurized gas) can flow inside, and one end is attached to one end 2 a of the measurement head 2. One end of the air supply path 3 communicates with the air outlet 7 of the measurement head 2 via the measurement head 2. The other end of the air supply path 3 communicates with an air supply source 8 that supplies compressed air. The air supply path 3 guides the compressed air supplied from the air supply source 8 to the air outlet 7 of the measurement head 2. In the present embodiment, the air supply source 8 supplies compressed air having a pressure of 0.5 MPa (with pressure fluctuation) to the air supply path 3. Note that the pressure in this specification refers to a so-called gauge pressure in which the atmospheric pressure is zero.

  The first regulator 4 is disposed in the air supply path 3 and reduces the pressure of the compressed air supplied from the air supply source 8. In the present embodiment, the first regulator 4 depressurizes 0.5 MPa (with pressure fluctuation) compressed air supplied from the air supply source 8 to 0.2 MPa (± 0.02 MPa) as a first predetermined value. To do.

  The second regulator 5 is disposed between the measurement head 2 of the air supply path 3 and the first regulator 4, and reduces the pressure of the compressed air supplied from the air supply source 8 via the first regulator 4. In the present embodiment, the second regulator 5 depressurizes the compressed air of 0.2 MPa supplied via the first regulator 4 to 0.05 MPa as a second predetermined value (corresponding to a predetermined value). In this way, the compressed air supplied from the air supply source 8 by the first regulator 4 is reduced to the first predetermined value that exceeds the atmospheric pressure, and the compressed air is reduced by the first regulator 4 by the second regulator 5. Is reduced to a second predetermined value. Thus, the first regulator 4 and the second regulator 5 cooperate to adjust the pressure of the compressed air ejected from the air ejection port 7 of the measurement head 2 to a predetermined value.

  The second regulator 5 includes a pressure gauge 9 on the back pressure side. The second regulator 5 is a so-called pressure reducing valve with a pressure gauge. The pressure gauge 9 of the second regulator 5 is disposed between the measuring head 2 and the regulators 4 and 5. The pressure gauge 9 indicates the pressure of the compressed air in the air supply path 3 on the back pressure side of the second regulator 5, that is, the pressure of the compressed air ejected from the air ejection port 7.

  Next, a clogging inspection method using the inspection apparatus 1 will be described. First, the operator drives the air supply source 8 in a state where the measuring head 2 is separated from the chuck table 10 to be inspected and the air outlet 7 is opened to the atmosphere. In the present embodiment, the air supply source 8 supplies compressed air having a constant pressure higher than the atmospheric pressure such as 0.5 MPa to the air supply path 3. Then, the first regulator 4 reduces the pressure of the compressed air supplied from the air supply source 8 to a first predetermined value higher than the atmospheric pressure such as 0.2 MPa in this embodiment. Then, the operator operates the handle of the second regulator 5 to reduce the pressure of the compressed air supplied from the air supply source 8 by the second regulator 5 to a second predetermined value such as 0.05 MPa in this embodiment. To do. Thus, the pressure of the compressed air ejected from the air ejection port 7 of the measuring head 2 is adjusted to the second predetermined value with the air ejection port 7 opened to the atmosphere.

  Thereafter, as shown in FIG. 3, the operator presses the other end 2b of the measuring head 2, that is, the elastic member 6 to a desired position on the surface 11a of the porous portion 11 of the chuck table 10 to be inspected, Compressed air is ejected from the air ejection port 7. Then, the jetted compressed air passes through the porous portion 11 and is jetted from around the measuring head 2 on the surface 11 a of the porous portion 11. Due to the resistance when the compressed air passes through the porous portion 11, the pressure of the compressed air in the measuring head 2, that is, the pressure of the compressed air ejected from the air ejection port 7 increases. Then, the operator reads the pressure of the compressed air ejected from the air jet port 7 indicated by the pressure gauge 9, measures the pressure of the compressed air, and measures the pressure of the compressed air, thereby measuring the desired position described above. Perform clogging measurement. Then, the operator measures the pressure of the compressed air ejected from the air ejection port 7 while pressing the measuring head 2 in order on a plurality of locations on the surface 11a of the porous portion 11 of the chuck table 10 in the same manner as described above. .

  And when an operator raises at least one rise value among the rise values of the pressure of the compressed air measured by pressing the measuring head 2 against a plurality of locations on the surface 11a of the porous portion 11, a predetermined threshold value is exceeded. Then, it is determined that the porous portion 11 of the chuck table 10 to be inspected is clogged. Thus, the operator uses the compressed air pressure measured at the porous portion 11 of the chuck table 10 to be inspected to determine that the clogged state is present. When inspecting clogging of the porous portion 11 of the chuck table 10 installed in the cutting apparatus, the measuring head is placed around a chip in which a cutting defect such as chipping occurs on the back surface of the front surface 11a of the porous portion 11. It is desirable to press 2. Note that the above-described threshold value is preferably set to a value determined in a generally conceivable range so that it can be reliably determined whether or not the porous portion 11 is clogged.

  Here, for example, the compressed air measured at the porous portion 11 that is not clogged when the pressure of the compressed air ejected from the air outlet 7 at the time of opening to the atmosphere is 0.04 MPa, 0.05 MPa, and 0.06 MPa. As shown in FIG. 4, the pressure is 0.073 MPa, 0.08 MPa, and 0.089 MPa. On the other hand, the compressed air measured at the clogged porous portion 11 when the pressure of the compressed air ejected from the air outlet 7 at the time of opening to the atmosphere is 0.04 MPa, 0.05 MPa, and 0.06 MPa. As shown in FIG. 4, the pressure is 0.079 MPa, 0.088 MPa, and 0.096 MPa. Therefore, it is possible to reliably measure whether or not the clogged state is caused by the threshold value described above. In FIG. 4, the horizontal axis indicates the pressure of the compressed air ejected from the air outlet 7 indicated by the pressure gauge 9 when the atmosphere is open, and the vertical axis indicates the compression measured at the porous portion 11 indicated by the pressure gauge 9. Indicates air pressure. Also, the solid line in FIG. 4 shows the pressure of the compressed air measured at the porous portion 11 that is not clogged, and the one-dot chain line in FIG. 4 shows the pressure of the compressed air measured at the porous portion 11 in the clogged state. Show.

  As described above, the inspection apparatus 1 according to the present embodiment is a compressed air that is ejected from the air ejection port 7 of the measurement head 2 that is brought into close contact with the desired position of the surface 11 a of the porous portion 11 of the chuck table 10 by the elastic member 6. The clogging of the porous portion 11 made of the porous material is measured on the basis of the pressure. For this reason, it is not necessary to install a pressure gauge in a vacuum suction path or the like of a processing device such as a cutting device, and it is possible to easily measure clogging without preparing a suction source (cutting device). Air blow piping provided in the processing equipment such as can be used as an air supply source, so measurement can be easily performed). Further, since the clogging of the porous portion 11 is measured based on the pressure of the compressed air ejected from the air ejection port 7 of the measuring head 2, the clogging of the porous material is measured without forming the chuck table 10. Can do. Therefore, it is possible to inspect the clogging of the porous material without requiring extensive preparation.

  In addition, since the air outlet 7 is provided in a part of the other end 2b of the measuring head 2 and the diameter of the air outlet 7 is reduced to 1 mm or more and 5 mm or less, the porous portion 11 is also partially clogged. There is also an effect that it can be measured. Therefore, partial clogging of the porous material can be measured.

  Further, the pressure of the compressed air is adjusted by the regulators 4 and 5, and in particular, the second regulator 5 reduces the pressure of the compressed air to a relatively low second predetermined value. The increase in the pressure of compressed air from the value increases. Because of this, a subtle blockage can be found. In addition, since the pressure of the compressed air when the atmosphere is released can always be measured by the regulators 4 and 5 as a constant pressure, determination based on the absolute value of the pressure of the compressed air is possible. There is no need to compare with a clogged sample to determine. Therefore, since the clogged sample is not required, the clogging of the porous material can be inspected without requiring a large preparation.

  Further, even when the porous portion 11 is not clogged, the increase value of the compressed air when the measurement head 2 is pressed against the surface 11a of the porous portion 11 and the compressed air is ejected from the air outlet 7 is as follows. It changes depending on the count of the porous portion 11. For example, as the count of the porous portion 11 increases, the resistance of the compressed air when passing through the porous portion 11 increases, and the pressure rise value of the compressed air increases. For this reason, the inspection apparatus 1 grasps in advance the pressure increase value of the compressed air measured in the porous portion 11 that is not clogged with each count, so that the compressed air is applied to the surface 11a of the porous portion 11 whose count is unknown. Can be ejected from the air ejection port 7 of the measuring head 2, the pressure indicated by the pressure gauge 9 can be grasped, and the count of the porous portion 11 whose count is unknown can be estimated.

  In the embodiment described above, an example in which the inspection apparatus 1 inspects clogging of the porous portion 11 of the chuck table 10 is shown. However, the inspection apparatus 1 of the present invention may inspect clogging of only the porous portion 11 without being configured in the chuck table 10. In the present invention, only one or three or more regulators 4 and 5 may be provided. Further, in the present invention, the second regulator 5 may not be a pressure reducing valve, and a pressure gauge 9 separate from the second regulator 5 may be provided.

  The present invention is not limited to the above embodiment. That is, various modifications can be made without departing from the scope of the present invention.

1 Clogging inspection device for porous material 2 Measuring head 2b The other end (lower surface)
3 Air supply path 4 First regulator (regulator)
5 Second regulator (regulator)
6 Elastic member 7 Air outlet 8 Air supply source 9 Pressure gauge 11 Porous part (porous material)

Claims (1)

A clogging inspection device for inspecting clogging of a porous material,
A measurement head having an air outlet opening in a part of the lower surface covered with an elastic member;
An air supply path with one end communicating with the air outlet of the measuring head and the other end communicating with an air supply source;
A regulator that is disposed in the air supply path and adjusts the pressure of the air ejected from the air ejection port of the measurement head to a predetermined value;
A pressure gauge disposed between the measuring head and the regulator, and indicating a pressure of air ejected from the air ejection port,
After adjusting the pressure of the ejected air to the predetermined value, the measurement is performed by ejecting the air while measuring the pressure of the air while pressing the lower surface of the measurement head to a desired position of the porous material,
A clogging inspection device for a porous material, which is used to determine that the air pressure measured with the porous material to be inspected is clogged.

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