JP6226609B2 - Porous material clogging inspection device - Google Patents

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 workpiece scraps or the like 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 porous ceramics has occurred, after forming a chuck table by bonding the porous ceramics to the frame, the entire upper surface of the porous ceramics is covered with a sheet or the like, and the chuck table A means (Patent Document 2) has been devised, such as how much the sheet is sucked by applying a negative pressure (Patent Document 1), and measuring and judging the pressure and flow rate of the suction passage that can act on the chuck table. It was.

  However, in the methods described in these Patent Documents 1 and 2, it is necessary to form a chuck table, and it is necessary to prepare a part (ejector or the like) serving as a suction source in order to apply a suction force. There was a problem that clogging of a partial porous portion could not be measured.

  Therefore, the applicant of the present invention is provided with a measurement head having an air jet opening, a pressure gauge indicating the pressure of the air jetted from the air jet, and the like. We propose a clogging inspection device for porous materials that can measure partial clogging.

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

  The clogging inspection device for a porous material determines clogging based on a slight difference in air pressure. However, if the pressing force of the measuring head varies, the air pressure indicated by the pressure gauge also varies. For this reason, when a measurer changes, a measured value changes and the problem that it cannot manage with a fixed value was left.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a porous material clogging inspection apparatus capable of easily inspecting clogging of a porous material even if operators are different. That is.

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 jet opening in a part of a lower surface covered with a cover member having one end, an air supply path with one end communicating with the air jet port of the measurement 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 with the air ejection port released to the atmosphere ; and between the measurement head and the regulator And a pressure gauge indicating the pressure of the air ejected from the air ejection port, and the measuring head can accommodate the measuring element having the lower surface to which the air ejection port is open, and the measuring element Has a deep recess A measuring element cover having a ceiling portion that houses the measuring element in contact with the porous material and forms a sufficient space with the upper part of the measuring element; and a ceiling of the concave portion of the measuring element cover An elastic member having a height at which the lower surface of the probe protrudes from the probe cover when inserted between the probe and the upper part of the probe accommodated in the recess. The air is jetted out while pressing the lower surface of the measuring element of the measuring head that blows out the air adjusted to the predetermined value from the air jetting port to a desired position of the porous material, and the pressure of the air is reduced. When measuring with a pressure gauge and using the rise value of the air pressure from the released state to determine that the porous material to be inspected is clogged, the measurement is made via the probe cover. When the child is pressed against the porous material with a predetermined force or more, the elastic member contracts. The lower end of the surveying stator cover that is, that the elastic member abuts against the porous material in a state of being elastically deformed in the elastic range, leaving a predetermined contraction potential, characterized in that can be pressed to the measuring element at a constant pressure And
In the clogging inspection apparatus for a porous material, the air outlet may be formed in a circular shape having a diameter of 1 mm or more and 5 mm or less.
In the clogging inspection apparatus for a porous material, the regulator is disposed in the air supply path, and the pressure of the air supplied from the air supply source is released to the atmosphere at the first air outlet. The pressure of the air that is disposed between the first regulator that depressurizes to a predetermined value, the measuring head of the air supply path, and the first regulator, and that is supplied from the air supply source via the first regulator. And a second regulator for reducing the pressure to the second predetermined value which is the predetermined value in a state where the air outlet is released to the atmosphere.

  According to the porous material clogging inspection apparatus of the present invention, it becomes possible to press the measuring element with a constant pressure, and even if the operator is different, the inspection of clogging of the porous material is performed with a constant air pressure. There is an effect that it can be performed.

FIG. 1A is an explanatory diagram illustrating a configuration of the inspection apparatus according to the embodiment, and FIG. 1B is an explanatory diagram illustrating a clogging inspection of the inspection apparatus illustrated in FIG. is there. FIG. 2 is a perspective view showing a schematic configuration of a measuring head 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 and 2. FIG. 1A is an explanatory diagram illustrating a configuration of the inspection apparatus according to the embodiment, and FIG. 1B is an explanatory diagram illustrating a clogging inspection of the inspection apparatus illustrated in FIG. FIG. 2 is a perspective view showing a schematic configuration of the measurement head 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 (not shown).

  In this embodiment, the chuck table 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 apparatus such as a cutting apparatus for cutting a workpiece such as an optical device wafer, a grinding apparatus for grinding the workpiece, or a polishing apparatus for polishing the workpiece, and holds the workpiece.

  The chuck table 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 is installed in the above-described processing apparatus, connected to a vacuum suction source (not shown) through a vacuum suction path (not shown), and held by sucking a workpiece placed on the surface 11a of the porous portion 11. To do. In the porous portion 11 of the chuck table, 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, so that the workpiece is sufficiently filled. It may become impossible to suck. If the chuck table cannot sufficiently suck the workpiece, the workpiece may move during machining such as cutting, grinding, and polishing, resulting in machining defects such as chipping on the back surface of the workpiece. is there.

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

  As shown in FIGS. 1A and 1B, 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), a second And a regulator 5 (corresponding to a regulator). In the measuring head 2, an air outlet 7 is opened at a part of the lower surface covered with elastic cover members 24 and 26. As shown in FIGS. 1 (a), 1 (b) and 2, the measuring head 2 includes a measuring element 21, a measuring element cover 22, and an elastic member 23 having a lower surface through which the air outlet 7 is opened. Prepare.

  The measuring element 21 is made of a metal such as stainless steel, and as shown in FIG. 2, a space K1 is provided on the inner side, and the appearance is formed in a cylindrical shape. An air supply path 3 communicating with the space K1 is connected to the upper end portion of the measuring head 2. The lower surface of the measuring head 2 is covered with an elastic cover member 24, and an air jet port 7 communicating with the space K1 is opened in a part of the lower surface. 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 spout 7 is 1 mm or more is that, if the diameter of the air spout 7 is less than 1 mm, it depends on the processing accuracy of the air spout 7 and the influence of foreign matter on the surface 11a of the porous portion 11 of the chuck table. This is because the compressed air pressure at the time of measurement varies, and it is impossible to accurately measure whether or not the air 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 cover member 24 is made of an elastic resin such as rubber, is formed in a thick disk shape, and covers the lower surface of the probe 21. The cover member 24 is provided with a communication hole 24 a that communicates with the air outlet 7. The communication hole 24 a is formed in the same size as the air jet port 7.

  The probe cover 22 has a recess 25 having a depth that can accommodate the probe 21, and accommodates the probe 21 whose lower surface is in contact with the porous portion 11 via the cover member 24. The probe cover 22 is made of metal such as stainless steel, and accommodates the probe 21 in the recess 25 so as to be slidable along the axis. The inner diameter of the recess 25 and the outer diameter of the measuring element 21 are formed such that the measuring element 21 is slidable along the axis with respect to the measuring element cover 22 and does not rattle in the radial direction. .

  The lower end of the probe cover 22 is covered with a cover member 26 over the entire circumference of the recess 25. Similar to the cover member 24, the cover member 26 is made of a resin having elasticity such as rubber and is formed in a thick annular shape. Further, a through hole 27 through which the air supply path 3 passes is provided in the outer wall of the measuring element 21.

  As shown in FIG. 1B, the probe cover 22 has a lower surface of the probe 21 accommodated in the recess 25 in contact with the porous portion 11 through the cover member 24, and a lower end at the porous portion through the cover member 26. 11 is provided with a ceiling portion 25a that forms a sufficient space K2 with the upper portion of the measuring element 21. The ceiling part 25a is a wall on the back side of the recess 25, and is opposed to the upper part of the measuring element 21 with a gap. The space K2 is a part of the space in the recess 25.

  The elastic member 23 is inserted between the ceiling portion 25 a that is the back wall of the recess 25 of the probe cover 22 and the upper portion of the probe 21 accommodated in the recess 25. The elastic member 23 is an elastically deformable member such as a spring or rubber piece made of metal or the like. In the present embodiment, the elastic member 23 is a compression coil spring, but the present invention is not limited to this. When the elastic member 23 is inserted between the ceiling portion 25a and the upper part of the measuring element 21, the lower surface of the measuring element 21 is removed from the measuring element cover 22 when the elastic member 23 has a natural length that is not elastically deformed or hardly deformed. It has a protruding height. The elastic member 23 is inserted between the ceiling portion 25a and the upper part of the measuring element 21, and when the lower surface of the measuring element 21 is in contact with the porous portion 11 via the elastic member 23, the elastic member 23 is elastically deformed in a direction in which the entire length becomes shorter. Do (shrink). Then, when the lower end of the probe cover 22 abuts against the porous portion 11 via the cover member 26, the elastic member 23 has a predetermined shrinkage allowance so that the probe 21 is directed toward the porous portion 11 at a constant pressure. Can be pressed. That is, the elastic member 23 contracts within the elastic range when the lower surface of the probe 21 contacts the porous portion 11 via the elastic member 23 and the lower end of the probe cover 22 hits the porous portion 11 via the cover member 26. Will be.

  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 communicates with the space K1 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, an operator drives the air supply source 8 in a state where the measuring head 2 is separated from the chuck table 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. 1B, the operator presses the lower surface of the measuring head 2, that is, the cover member 24 to a desired position on the surface 11 a of the porous portion 11 of the chuck table 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 sequentially pressing the measurement head 2 against a plurality of locations on the surface 11a of the porous portion 11 of the chuck table, as in the above-described process.

  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 to be inspected is clogged. Thus, the operator uses the pressure of the compressed air measured at the porous portion 11 of the chuck table to be inspected to determine that it is clogged. When the clogging of the porous portion 11 of the chuck table installed in the cutting apparatus is inspected, the measuring head 2 is arranged around a chip in which a cutting defect such as a chip occurs on the back surface of the front surface 11a of the porous portion 11. It is desirable to press. 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. In addition, the operator may be partially clogged at a location where the pressure increase of the compressed air measured by pressing the measuring head 2 against the surface 11a of the porous portion 11 exceeds a predetermined threshold. judge.

  Further, when the measuring element 21 is used to determine that the porous part 11 to be inspected is clogged by pressing the lower surface to a desired position on the surface 11a of the porous part 11, the operator uses the measuring element. The probe 21 is pressed against the surface 11 a of the porous portion 11 through the cover 22 with a predetermined force or more. Then, the elastic member 23 contracts and the probe cover 22 descends, and the lower end of the lowered probe cover 22 leaves the elastic member 23 via the cover member 26 while leaving a predetermined shrinkage allowance of the porous portion 11. It hits the surface. Since the elastic member 23 is elastically deformed within the elastic range, the measuring element 21 can be pressed against the surface 11a of the porous portion 11 with a constant pressure via the cover member 26. The predetermined force means that when the lower surface of the probe 21 is pressed to a desired position on the surface 11 a of the porous portion 11, the lower end of the probe cover 22 abuts against the surface of the porous portion 11 via the cover member 26. The power of the degree.

  As described above, the inspection apparatus 1 according to the present embodiment is configured so that the compressed air ejected from the air outlet 7 of the measurement head 2 that is brought into close contact with the desired position of the surface 11a of the porous portion 11 of the chuck table by the cover member 24. Based on the pressure, clogging of the porous portion 11 made of the porous material is measured. 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 can be measured without forming a chuck table. it can. Therefore, it is possible to inspect the clogging of the porous material without requiring extensive preparation.

  Moreover, since the air outlet 7 is provided at a part of the other end 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 clogged state of 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. For this reason, subtle clogging can also 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, the determination based on the absolute value of the pressure of the compressed air is possible. For example, whether the air is clogged or not. 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.

  Further, when the probe 21 is pressed against the surface 11 a of the porous portion 11 via the probe cover 22 and the lower end of the probe cover 22 abuts against the surface 11 a of the porous portion 11 via the cover member 26, the elastic member 23 leaves an allowance for shrinkage and elastically deforms within the elastic range. For this reason, the elastic member 23 can press the probe 21 against the surface 11 a of the porous portion 11 with a constant pressure in response to the descend of the probe cover 22. Therefore, it becomes possible to press the measuring element 21 with a constant pressure, and even if the operator is different, the increased value of the pressure of the compressed air becomes a value corresponding to the clogged state of the porous portion 11, and the constant compressed air is The clogging of the porous portion 11 can be easily inspected by the pressure.

  In the embodiment described above, an example in which the inspection apparatus 1 inspects clogging of the porous portion 11 of the chuck table is shown. However, the inspection apparatus 1 of the present invention may inspect clogging of only the porous portion 11 without being configured as a chuck table. 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.

DESCRIPTION OF SYMBOLS 1 Porous material clogging inspection apparatus 2 Measuring head 3 Air supply path 4 1st regulator (regulator)
5 Second regulator (regulator)
7 Air outlet 8 Air supply source 9 Pressure gauge 11 Porous part (porous material)
21 Measuring element 22 Measuring element cover 23 Elastic member 24 Cover member 25 Recessed part 25a Ceiling part 26 Cover member K2 space

Claims (3)

A clogging inspection device for inspecting clogging of a porous material,
A measurement head having an air outlet opening on a part of the lower surface covered with an elastic cover 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 in a state in which the air ejection port is released to the atmosphere ;
A pressure gauge disposed between the measuring head and the regulator, and indicating a pressure of air ejected from the air ejection port,
The measuring head is
A probe having the lower surface where the air outlet is open;
A recess having a depth capable of accommodating the measuring element, and a lower surface having a ceiling portion that accommodates the measuring element in contact with the porous material and forms a sufficient space with the upper part of the measuring element A probe cover;
Elasticity having a height at which the lower surface of the probe protrudes from the probe cover when inserted between the ceiling of the recess of the probe cover and the upper part of the probe accommodated in the recess. A member, and
The air adjusted to the predetermined value by the regulator is ejected from the air ejection port while the lower surface of the measuring element of the measuring head is pressed to a desired position of the porous material to eject the air. When the pressure is measured with the pressure gauge and the rise value of the air pressure from the released state is used to determine that the porous material to be inspected is clogged , the probe cover is passed through the probe cover. When the measuring element is pressed against the porous material with a predetermined force or more, the elastic member contracts and lowers the lower end of the measuring element cover within the elastic range leaving the elastic member with a predetermined shrinkage margin. A clogging inspection device for a porous material that can press the measuring element with a constant pressure by striking the porous material in an elastically deformed state.   The clogging inspection device for a porous material according to claim 1, wherein the air outlet is formed in a circular shape having a diameter of 1 mm or more and 5 mm or less.   The regulator is
  A first regulator disposed in the air supply path and depressurizing the pressure of the air supplied from the air supply source to a first predetermined value in a state where the air outlet is released to the atmosphere;
  A state in which the pressure of the air supplied from the air supply source via the first regulator is released to the atmosphere by being arranged between the measuring head of the air supply path and the first regulator. A second regulator for reducing the pressure to a second predetermined value, which is the predetermined value,
  The clogging inspection device for a porous material according to claim 1, comprising:

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