Grinding method and grinding device

Abstract

To provide a grinding method and a grinding device which can highly accurately grind a substrate in which a dissimilar material part is embedded in a short time.SOLUTION: A grinding method for rotating a substrate 40 in which a dissimilar material part 42 made of a material different from a main component is embedded, and grinding the substrate 40 with a grinding wheel 3 while rotating and downward feeding the grinding wheel 3, comprises the steps of: continuously imaging a processing surface of a substrate 30 with an image sensor 10 during grinding; analyzing an exposure amount of the dissimilar material part 42 from the image data obtained by the image sensor 10; and continuously executing the grinding to a stage where the exposure amount of the dissimilar material part 42 reaches a prescribed set value from the state where the dissimilar material part 42 starts to be exposed. With this configuration, the grinding state can be correctly grasped without repeating execution and stop of the grinding in order to detect the exposure of the dissimilar material part 42 like a conventional technique. Consequently, the substrate 40 in which the dissimilar material part 42 is embedded can be efficiently and highly accurately ground in a short time.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a grinding method and a grinding apparatus, and more particularly to a grinding method and a grinding apparatus for grinding a substrate having a different material embedded therein. [Background technology]

[0002] 2. Description of the Related Art In the manufacture of semiconductor substrates and the like, there is known a technique for thinning a substrate by grinding the substrate having electrodes and the like embedded in layers of the substrate, the electrodes being made of a material different from the main constituent material.

[0003] For example, Patent Document 1 discloses a method for manufacturing a semiconductor device using an insulating isolated Si substrate in which a Si through electrode (TSV: Through Silicon Via) is embedded, in which the Si support substrate is removed by a grinding method or the like to expose the Cu film of the Si through electrode.

[0004] For example, Patent Document 2 discloses a technique for grinding a large composite substrate made of a Fan Out Panel Level Package (FOPLP) technique that includes resin, metal, and a semiconductor device chip. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-140162 A [Patent Document 2] JP 2020-102481 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the above-mentioned conventional substrate grinding methods and apparatuses have some points that need improvement in order to shorten the processing time and improve the production efficiency of substrates.

[0007] Specifically, in a process of grinding a substrate in which a dissimilar material portion made of a material different from the main material of the layers constituting the substrate is embedded, it may be required to expose the entire dissimilar material portion. For example, in a process of grinding a substrate in which a copper electrode (Cu Via) is embedded inside a mold resin or a silicon wafer, it is required to expose the entire copper electrode.

[0008] In the conventional grinding method, the grinding process is started, and after the grinding process is performed to a preset end thickness, the grinding process is stopped and the rotation of the workpiece is stopped, and the exposed copper electrode on the machined surface is confirmed by visual inspection and microscopic inspection. Furthermore, in the method of measuring the dimensions of the machined surface using a contact type thickness gauge, it is necessary to end the grinding process and stop the rotation of the workpiece in order to measure the thickness of the substrate.

[0009] If visual or microscopic inspection determines that the copper electrodes are not fully exposed, or if measurement with a thickness gauge determines that the thickness of the substrate does not reach the specified dimension, grinding is performed again.

[0010] In a situation where high-precision processing is required for an extremely thin substrate, it is difficult to expose the entire copper electrode and finish it to the specified dimensions in one grinding process. Therefore, the above-mentioned grinding process, measurement, visual inspection, and microscope inspection are repeated until the entire copper electrode is exposed and the specified target dimensions are reached.

[0011] Therefore, the grinding process of the conventional technology requires repeated start and stop of the grinding process, which requires many grinding processes, measurements, and inspections, making it difficult to reduce the processing time. This has been an issue in improving the productivity of substrates.

[0012] In particular, when grinding a substrate with a structure in which a heterogeneous material such as Cu (copper) is embedded in a resin substrate, if the resin contains a large amount of filler such as spherical silica (50% or more), it is difficult to measure the thickness of the resin with non-contact near-infrared light. In other words, since the infrared light is scattered by the filler, it is not possible to obtain an interference waveform of the infrared light from the front and back surfaces of the substrate.

[0013] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a grinding method and grinding apparatus capable of grinding a substrate having a dissimilar material embedded therein with high precision in a short period of time. [Means for solving the problem]

[0014] The grinding method of the present invention is a grinding method in which a substrate having a different material portion made of a material different from a main component material is rotated, and the substrate is ground with the grinding wheel by down-feeding while rotating the grinding wheel, At an image acquisition time set in synchronization with the rotation speed of the substrate, The processed surface of the substrate is continuously imaged by an image sensor, and image data obtained by the image sensor is Color information and image pattern information and continuously executing the grinding process from a state where the different material portion starts to be exposed until the exposed amount of the different material portion reaches a predetermined set value.

[0015] The grinding device of the present invention further comprises a substrate chuck which rotates while holding a substrate having an embedded dissimilar material portion made of a material different from a main constituent material, a grinding head which holds a grinding wheel facing the substrate held by the substrate chuck and rotates about an axis of rotation that is offset in a radial direction from the axis of rotation of the substrate chuck, a feed mechanism which feeds the grinding head or the substrate chuck in a direction in which the grinding wheel and the substrate approach or move away from each other, and a feed mechanism which feeds the grinding head or the substrate chuck in a direction in which the grinding wheel and the substrate approach or move away from each other, and a grinding mechanism which feeds the grinding head or the substrate chuck in a direction in which the grinding wheel and the substrate move toward or ... The image acquisition time is set in synchronization with the rotation speed of the substrate. An image sensor for capturing an image, and image data of the processing surface captured by the image sensor Color information and image pattern informationand an image analysis device that analyzes the amount of exposure of the dissimilar material portion from the machining surface, and the feed mechanism is controlled based on the amount of exposure analyzed by the image analysis device, and the dissimilar material portion exposed from the machining surface is ground. Effect of the Invention

[0016] According to the grinding method of the present invention, a substrate having a dissimilar material portion embedded therein is rotated, and a grinding wheel is down-fed while rotating to grind the substrate with the grinding wheel. During the grinding process, the processed surface of the substrate is continuously imaged by an image sensor, the amount of exposure of the dissimilar material portion is analyzed from the image data obtained by the image sensor, and the grinding process is continued from the state where the dissimilar material portion begins to be exposed until the amount of exposure of the dissimilar material portion reaches a predetermined set value. This makes it possible to accurately grasp the grinding status without having to once stop the grinding process to detect the exposure of the dissimilar material portion as in the conventional technology. Therefore, the substrate having a dissimilar material portion embedded therein can be efficiently and highly accurately ground in a short time without repeatedly starting and stopping the grinding process.

[0017] According to the grinding method of the present invention, the substrate may be a resin substrate, and the dissimilar material portion may include a metal material. The grinding method of the present invention can grind the resin substrate having the metal material embedded therein, and expose the dissimilar material portion made of the metal material with high efficiency and high accuracy.

[0018] According to the grinding method of the present invention, the image sensor may have an image acquisition time of 1 to 100 microseconds, and the light source may be a spot strobe type. With this configuration, the different material portion exposed during the grinding process can be detected quickly and with high accuracy, and the grinding process of the substrate can be efficiently performed in a short time without repeatedly starting and stopping the grinding process.

[0019] The grinding device of the present invention includes a substrate chuck that holds and rotates a substrate in which a dissimilar material portion made of a material different from the main constituent material is embedded, a grinding head that holds a grinding wheel facing the substrate held by the substrate chuck and rotates around a rotation axis at a position offset in the radial direction from the rotation axis of the substrate chuck, a feed mechanism that feeds the grinding head or the substrate chuck in a direction in which the grinding wheel and the substrate approach or move away from each other, an image sensor that captures an image of the processed surface of the substrate away from the grinding wheel in the process of grinding the rotating substrate with the rotating grinding wheel, and an image analyzer that analyzes the amount of exposure of the dissimilar material portion from the image data of the processed surface captured by the image sensor, and the feed mechanism is controlled based on the amount of exposure analyzed by the image analyzer to grind the dissimilar material portion exposed from the processed surface. This allows high-precision substrate grinding to be performed efficiently in a short time, thereby improving the productivity of substrates. [Brief description of the drawings]

[0020] [Figure 1] 1 is a diagram showing a schematic configuration of a grinding device according to an embodiment of the present invention; [Diagram 2] 2 is a diagram showing the vicinity of a tip of an image sensor of the grinding device according to the embodiment of the present invention. FIG. [Diagram 3] 1A to 1C are diagrams showing schematic configurations of a workpiece before grinding in a grinding method according to an embodiment of the present invention; [Figure 4] FIG. 13 is a diagram showing a schematic configuration of a grinding device according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, a grinding device 1 according to an embodiment of the present invention and a grinding method using the same will be described in detail with reference to the drawings.

[0022] FIG. 1 is a diagram showing a schematic configuration of a grinding device 1 according to an embodiment of the present invention. 1, the grinding device 1 is a processing device used for grinding one main surface of a substrate 40. More specifically, the grinding device 1 is used in a process of grinding a flat surface of the substrate 40 in which a dissimilar material portion 42 made of a different material is embedded, to expose the dissimilar material portion 42 embedded in the substrate 40.

[0023] A dissimilar material portion 42 made of a material different from the main material constituting a main body portion 41 of the substrate 40 is embedded in the substrate 40 which is the processing target of the grinding device 1. For example, the substrate 40 has a dissimilar material portion 42 such as a Cu (copper) electrode, which is different from the main material constituting the main body portion 41, embedded in the main body portion 41 which is mainly made of a resin material or the like.

[0024] The grinding apparatus 1 includes a substrate chuck 4 that holds the substrate 40, a grinding head 2 that holds the grinding wheel 3, a feed mechanism (not shown) that feeds the grinding head 2, an image sensor 10 that images the machined surface of the substrate 40, and an image analysis device 20 that analyzes the exposed amount of the different material portion 42 from the image data of the image sensor 10.

[0025] The substrate chuck 4 is a porous chuck that adsorbs and holds the substrate 40. The substrate chuck 4 has a substantially flat plate shape and is attached above a grinding table (not shown). The substrate chuck 4 is, for example, a vacuum chuck, and is provided with a vacuum pump (not shown) or the like for creating a negative pressure inside the substrate chuck 4 to adsorb the substrate 40.

[0026] The grinding table on which the substrate chuck 4 is placed is rotated by a driving means (not shown). This causes the substrate chuck 4 to rotate horizontally. During grinding, the substrate 40 is placed on the upper surface of the substrate chuck 4, and the substrate 40 rotates horizontally together with the substrate chuck 4.

[0027] The grinding head 2 is a mechanism that holds and rotates the grinding wheel 3. The grinding head 2 is provided so that its rotation axis is offset in the radial direction from the rotation axis of the substrate chuck 4. The grinding wheel 3 is held below the grinding head 2 so as to face the upper surface of the substrate 40 held by the substrate chuck 4.

[0028] The grinding wheel 3 is a cup wheel type grinding wheel that grinds from above the horizontally rotating substrate 40. The grinding wheel 3 has a roughly disk-shaped cup wheel that is held by the grinding head 2 and rotates horizontally, and is attached in a roughly circular shape near the lower periphery of the cup wheel.

[0029] Although not shown in the figure, the feed mechanism has, for example, a ball screw or the like, and feeds the grinding head 2 in the rotation axis direction, i.e., the vertical direction, so that the grinding wheel 3 and the substrate 40 approach or separate from each other. The feed mechanism may be provided on the substrate chuck 4 side so as to feed the substrate 40 in the vertical direction.

[0030] The grinding head 2 is driven by a driving means (not shown) to rotate horizontally, and is fed vertically by a feed mechanism (not shown). That is, the grinding wheel 3 is fed by the feed mechanism while rotating horizontally together with the grinding head 2, and moves in a direction approaching or moving away from the substrate 40. In the process of grinding the substrate 40, the cutting edge at the bottom of the horizontally rotating grinding wheel 3 comes into contact with the upper surface of the substrate 40, which is attracted to the upper surface of the substrate chuck 4 and rotates horizontally, and the substrate 40 is ground.

[0031] The grinding apparatus 1 also has a grinding water supply device 25 and a grinding water supply nozzle 26 provided on the grinding water supply device 25. The grinding water supply device 25 is a device that supplies pure water to the vicinity of the contact portion between the substrate 40 and the grinding wheel 3 via the grinding water supply nozzle 26. That is, pure water is supplied from the grinding water supply device 25, and is sprayed from the nozzle of the grinding water supply nozzle 26 toward the vicinity of the contact portion between the upper surface of the substrate 40 and the cutting edge of the grinding wheel 3.

[0032] The image sensor 10 is a device that captures an image of the processed surface of the substrate 40. The image sensor 10 is an image sensor that uses an image sensor such as a charge-coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS).

[0033] In particular, in order to quickly capture the processed surface of the rotating substrate 40 and obtain high-precision image data that enables grinding processing to expose the disparate material portion 42, it is desirable for the image sensor 10 to be a sensor that utilizes a CMOS imaging element.

[0034] Although not shown, the image sensor 10 has a light source that irradiates light near an imaging location on the substrate 40, and captures an image by receiving reflected light from the substrate 40. Providing a light source that emits such strong light enables high-speed and high-precision imaging for achieving grinding.

[0035] The image sensor 10 is provided above the substrate 40 held by the substrate chuck 4 at a position not in contact with the grinding wheel 3 during the process of grinding the horizontally rotating substrate 40 with the horizontally rotating grinding wheel 3. In other words, the image sensor 10 is provided at a position away from the grinding wheel 3 during the grinding process, and captures an image of the processed surface of the substrate 40 away from the grinding wheel 3.

[0036] The image analysis device 20 is a device that analyzes the exposed amount of the different material portion 42 from image data of the processed surface of the substrate 40 captured by the image sensor 10. The image analysis device 20 is connected to the image sensor 10 and also to a control device (not shown) that controls the grinding process of the grinding device 1.

[0037] The image data analyzed by the image analysis device 20 is sent to the control device. The control device controls the drive means for rotating the substrate 40, the drive means for rotating the grinding wheel 3, and the feed mechanism for relatively moving the substrate 40 and the grinding wheel 3, based on the amount of exposure analyzed by the image analysis device 20. In this way, the different material portion 42 exposed from the processing surface of the substrate 40 is ground.

[0038] That is, the grinding device 1 continuously images the processed surface of the substrate 40 with the image sensor 10 during the grinding process, and continues to perform the grinding process from the state where the dissimilar material portion 42 begins to be exposed until the amount of exposure of the dissimilar material portion 42 reaches a predetermined set value.

[0039] The grinding apparatus 1 can perform high-precision continuous grinding of the substrate 40 efficiently in a short time without repeatedly starting and stopping the grinding process as in the conventional technology. Therefore, the grinding apparatus 1 can improve the productivity of the substrate 40.

[0040] The grinding apparatus 1 has an imaging water supply device 19 that supplies pure water to the vicinity of the location imaged by the image sensor 10. Specifically, the vicinity of the tip of the image sensor 10 is covered by a housing 12, and a pipe 18 that supplies pure water from the imaging water supply device 19 is connected to the housing 12. With this configuration, pure water is supplied from the imaging water supply device 19 to the inside of the housing 12 via the pipe 18. The imaging water supply device 19 may also serve as the grinding water supply device 25 described above.

[0041] FIG. 2 is a diagram showing the vicinity of the tip of the image sensor 10 of the grinding device 1. As shown in FIG. 2, the vicinity of the tip of the image sensor 10, that is, the vicinity of the imaging port 11, is covered by a housing 12. Pure water is supplied to the vicinity of the imaging port 11 from an imaging water supply device 19 (see FIG. 1) during grinding.

[0042] More specifically, the housing 12 has an inner housing 13 that covers the vicinity of the imaging port 11 of the image sensor 10, and an outer housing 15 that covers the inner housing 13. The area sandwiched between the inner housing 13 and the outer housing 15, i.e., the area outside the inner housing 13 and inside the outer housing 15, becomes a flow path for pure water.

[0043] An imaging window 14 is formed in the inner housing 13 near the imaging port 11, which transmits light emitted from a light source (not shown) and transmits reflected light from an imaging location on the substrate 40. The imaging window 14 transmits light for imaging, but is not an opening through which liquid can flow. Pure water supplied from an imaging water supply device 19 does not flow from inside the housing 12 to the image sensor 10.

[0044] Therefore, grinding debris of the substrate 40 and the like do not adhere to the imaging port 11 of the image sensor 10, thereby suppressing degradation of imaging performance. In addition, there is no risk of the elements and wiring system of the image sensor 10 becoming wet with pure water and being damaged.

[0045] A water outlet 17 is formed at the bottom of the outer housing 15, which allows the pure water in the housing 12 to flow out toward the substrate 40. That is, during grinding, the pure water supplied from the imaging water supply device 19 into the housing 12 passes near the imaging port 11 of the image sensor 10, i.e., near the imaging window portion 14 of the inner housing 13, and flows out near the imaging location on the substrate 40.

[0046] The above-mentioned configuration makes it possible to prevent grinding chips of the substrate 40 from scattering or circulating near the imaging port 11 of the image sensor 10. For example, even when grinding a resin substrate 40 in which a dissimilar material portion 42 made of a metal material is embedded, it is possible to prevent the imaging port 11 of the image sensor 10 and the imaging window portion 14 of the housing 12 from being scratched by hard metal chips. Therefore, a decrease in imaging accuracy caused by grinding chips or the like is suppressed, enabling high-precision imaging.

[0047] As described above, the image sensor 10 has a light source that irradiates light onto the substrate 40 and a camera that captures the reflected light. The light source of the image sensor 10 is a spot strobe type. The image acquisition time, i.e., the shutter speed, of the camera of the image sensor 10 is 1 to 100 microseconds. The image acquisition time of the image sensor 10 is set in synchronization with the rotation speed of the substrate 40. With this configuration, the different material portion 42 exposed during the grinding process can be detected quickly and with high accuracy.

[0048] In this way, the grinding device 1 can continuously capture images of the processed surface of the horizontally rotating substrate 40 at high speed during grinding using the image sensor 10. For example, even if the substrate 40 is an FOPLP substrate of about 300 mm square and the rotation speed is about 300 rpm, the processed surface of the substrate 40 can be imaged with high accuracy.

[0049] Then, the image analyzing device 20 analyzes the color and image pattern of the image data with high accuracy, and accurately grasps the exposed state of the dissimilar material portion 42. Then, in the grinding device 1, when the exposed amount of the dissimilar material portion 42 reaches a preset target value, the grinding process is stopped.

[0050] In this way, the grinding apparatus 1 can collect highly accurate image data without image flow by using the image sensor 10 that captures image data at high speed. Therefore, unlike the grinding apparatus 1 of the prior art, which does not repeatedly start and stop grinding to measure the thickness of the substrate 40 with a contact sensor, grinding can be performed continuously and reliably without stopping until the end point of the target processing position.

[0051] Moreover, the imaging window portion 14 of the housing 12 is provided so as to be inclined with respect to the processed surface of the substrate 40, i.e., the horizontal plane. Specifically, the inclination angle of the imaging window portion 14 with respect to the processed surface of the substrate 40 is 5 to 15 degrees, preferably 5 to 12 degrees, and most preferably 5 to 10 degrees.

[0052] By setting the inclination angle of the imaging window portion 14 to 5 degrees or more, diffuse reflection at the imaging window portion 14 can be suppressed, and the accuracy of the image data can be improved. Therefore, it becomes possible to obtain highly accurate image data, and therefore to perform highly accurate grinding processing.

[0053] On the other hand, if the inclination angle of the imaging window 14 exceeds 15 degrees, the angle deviation of the light beam due to refraction increases, so the distance from the imaging target location increases, resulting in errors in the measurement values. Therefore, an inclination angle within the above-mentioned range is preferable, and this angle allows for highly accurate imaging data to be acquired, realizing highly accurate grinding processing.

[0054] Although not shown, the grinding device 1 includes a focus mechanism for adjusting the position of the image sensor 10 and a tilt mechanism for adjusting the inclination of the image sensor 10. The focus mechanism can finely adjust the position of at least one of the light source, camera, and imaging window 14 of the image sensor 10, specifically, the height from the substrate 40. The tilt mechanism can finely adjust the inclination of at least one of the light source, camera, and imaging window 14 of the image sensor 10, i.e., the inclination angle with respect to the processing surface of the substrate 40. With this configuration, the image sensor 10 can obtain highly accurate imaging data.

[0055] Next, a grinding method using the grinding device 1 will be described in detail with reference to FIGS. FIG. 3 is a diagram showing the vicinity of a workpiece in a grinding method according to an embodiment of the present invention, in which FIG. 3(A) shows a schematic diagram of the shape of a substrate 40 before grinding, FIG. 3(B) shows a schematic diagram of the shape of a substrate 40 during grinding, and FIG. 3(C) shows a schematic diagram of the shape of a substrate 40 after grinding.

[0056] 3(A), a substrate 40 to be processed has a main body 41 and a different material portion 42 made of a material different from the main material constituting the main body 41 embedded inside the main body 41. That is, at least the main body 41 and the different material portion 42 embedded in the main body 41 are made of different materials.

[0057] Specifically, the substrate 40 to be processed by the grinding device 1 is a resin substrate, a semiconductor substrate, an insulating substrate, etc., and the main constituent materials of the substrate 40 are various resins, silicon, SiC (silicon carbide), gallium arsenide, sapphire, etc.

[0058] The grinding apparatus 1 exhibits excellent processing performance, particularly for resin substrates. For example, the grinding apparatus 1 is used for grinding large composite substrates made by FOPLP technology, including molded resin, metal, and semiconductor device chips.

[0059] The grinding apparatus 1 can also be used in other substrate manufacturing processes that use molding resin, such as Fan Out Wafer Level Package (FOWLP) and System In a Package (SiP).

[0060] Various resin materials such as epoxy resin, urethane resin, silicone resin, polyimide resin, etc. may be used as the main material constituting the substrate 40. Furthermore, silica filler may be inserted into the resin material constituting the substrate 40 as a resin substrate in order to improve electrical characteristics. The heterogeneous material portion 42 embedded in the substrate 40 may be an electrode or the like made of a metal material such as Cu, Au (gold), Ti (titanium), Al (aluminum), Pt (platinum), etc. The heterogeneous material portion 42 may also include a semiconductor material, an insulating material, etc.

[0061] 1 and 3(A), in the grinding process of substrate 40, substrate 40 is held on the upper surface of substrate chuck 4 and rotated horizontally by driving means. The cutting edge of grinding wheel 3, which is driven by driving means (not shown) and rotates horizontally, comes into contact with the processing surface, i.e., the upper surface, of rotating substrate 40, and the processing surface of substrate 40 is ground by the downfeed of grinding wheel 3.

[0062] During the grinding process, the processed surface of the substrate 40 is continuously imaged by the image sensor 10. Then, the image data obtained by the image sensor 10 is analyzed by the image analyzer 20. That is, the exposed amount of the different material portion 42 is found from the color information and image pattern information of the processed surface.

[0063] When the grinding process is performed, the main body portion 41 on the upper part of the substrate 40 is ground away, and the dissimilar material portion begins to be exposed, as shown in Fig. 3(B). As described above, the processed surface of the substrate 40 is imaged by the image sensor 10, and the exposed state of the dissimilar material portion 42 is accurately detected by analyzing the image data by the image analyzer 20.

[0064] Specifically, when a pre-specified color is detected in the image data of the processing surface of the substrate 40, the amount of exposure of the dissimilar material portion 42 is analyzed from the number of cells of that color pattern. This allows the degree of exposure of the dissimilar material portion 42 to be accurately determined.

[0065] Therefore, in the grinding method of this embodiment, there is no need for the process of temporarily suspending the grinding process by the grinding wheel 3, stopping the rotation of the substrate 40, and measuring the thickness of the substrate 40 in the dissimilar material portion 42 using a contact sensor or the like, as is required in the grinding method of the conventional technology.

[0066] Then, as shown in FIG. 3(C), when the upper ends of all of the dissimilar material portions 42 are exposed from the substrate 40, the image analysis device 20 accurately detects, by analyzing the image data, that the amount of exposure of the dissimilar material portions 42 has reached the set end value.

[0067] Specifically, when the number of cells of a pre-specified color pattern reaches or exceeds a certain condition, the image analyzer 20 determines that the exposed amount of the different material portion 42 reaches an end value.

[0068] Then, the control device controls the grinding wheel 3 to move away from the processing surface of the substrate 40, and then controls the grinding wheel 3 and the substrate 40 to stop rotating, thereby completing the grinding process.

[0069] In this way, according to the grinding method of this embodiment, the grinding process is continued from the state where the dissimilar material portion 42 starts to be exposed until the exposed amount of the dissimilar material portion 42 reaches a predetermined set value. That is, even if the substrate 40 is a resin substrate in which the dissimilar material portion 42, such as a metal, is embedded, continuous and efficient grinding process with excellent productivity can be performed without repeatedly starting and stopping the grinding process.

[0070] Next, a grinding device 101 will be described in detail with reference to FIG. 4 as a modified example of the embodiment. 4 is a diagram showing a schematic configuration of a grinding device 101. Note that components that have the same or similar functions and effects as those in the already-described embodiments are given the same reference numerals, and descriptions thereof will be omitted.

[0071] As shown in FIG. 4, the grinding apparatus 101 has a high-pressure water generator 30 that supplies high-pressure water, and a high-pressure water nozzle 31 that sprays the high-pressure water supplied from the high-pressure water generator 30 onto the grinding wheel 3.

[0072] The high-pressure water nozzle 31 is provided near the lower side of the grinding wheel 3 that is not in contact with the processing surface of the substrate 40 during grinding, and sprays high-pressure water toward the cutting edge of the grinding wheel 3 that is not in contact with the processing surface of the substrate 40.

[0073] The pressure of the high-pressure water ejected from the high-pressure water nozzle 31 is 3 to 20 MPa, preferably 10 to 14 MPa. The ejection angle of the high-pressure water ejected from the high-pressure water nozzle 31 is preferably 5 to 20 degrees, more preferably 8 to 12 degrees.

[0074] Also, there may be provided a plurality of high-pressure water nozzles 31. Also, the high-pressure water nozzle 31 may have a mechanism for swinging at a speed of 1 to 20 mm / sec with a swing width of 1 to 10 mm.

[0075] Such a configuration in which the high-pressure water generator 30 and the high-pressure water nozzle 31 are provided is particularly effective when a dissimilar material portion 42 made of a metallic material is embedded in a resin substrate 40. That is, the high-pressure water jetted from the high-pressure water nozzle 31 can jet off metal chips and the like adhering to the grinding wheel 3, thereby preventing clogging of the grinding wheel 3.

[0076] In this way, continuous grinding for a long period of time is possible by preventing clogging of the grinding wheel 3. Therefore, by combining the configuration in which the exposed state of the different material portion 42 is accurately detected using the image sensor 10 capable of high-speed imaging and continuous grinding is performed, a highly efficient and highly accurate continuous grinding process that was not possible with conventional technology is realized.

[0077] The grinding method according to the present embodiment is a processing method that is completely different from conventional cutting processing using a milling cutter with a diamond bit. According to the grinding method of the present embodiment, excellent processing performance that cannot be achieved by cutting processing using a milling cutter can be obtained, and efficient grinding processing with high flatness can be performed at low cost.

[0078] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0079] 1, 101 Grinding device 2 Grinding head 3 Grinding wheels 4 Substrate chuck 10 Image Sensor 11 Imaging port 12. Housing 13 Inner housing 14 Imaging window 15 Outer housing 16 water inlet 17 Water outlet 18 Piping 19 Imaging water supply device 20 Image analysis device 25 Grinding water supply device 26 Grinding water supply nozzle 30 High pressure water generator 31 High pressure water nozzle 40 Substrate 41 Main body 42 Different materials department

Claims

1. A grinding method for rotating a substrate having an embedded dissimilar material portion made of a material different from a main component material, and grinding the substrate with a grinding wheel by down-feeding the grinding wheel while rotating the substrate, comprising: a grinding method comprising: continuously capturing images of the processed surface of the substrate with an image sensor during the grinding process at an image acquisition time set in synchronization with the rotation speed of the substrate; analyzing an amount of exposure of the dissimilar material portion from color information and image pattern information of the image data obtained by the image sensor; and continuously executing the grinding process from a state where the dissimilar material portion begins to be exposed until the amount of exposure of the dissimilar material portion reaches a predetermined set value.

2. The grinding method according to claim 1 , wherein the substrate is a resin substrate, and the different material portion includes a metal material.

3. 3. The method according to claim 1, wherein the image sensor has an image acquisition time of 1 to 100 microseconds and a light source of a spot strobe type.

4. a substrate chuck that holds and rotates a substrate having a different material portion embedded therein, the different material portion being made of a material different from a main constituent material; a grinding head that holds a grinding wheel facing the substrate held by the substrate chuck and rotates about a rotation axis that is offset in a radial direction from a rotation axis of the substrate chuck; a feed mechanism for feeding the grinding head or the substrate chuck in a direction in which the grinding wheel and the substrate approach or move away from each other; an image sensor that captures an image of a processed surface of the substrate separated from the grinding wheel at an image acquisition time set in synchronization with a rotation speed of the substrate in a process of grinding the rotating substrate with the rotating grinding wheel; and an image analysis device that analyzes an exposed amount of the different material portion from color information and image pattern information of the image data of the processing surface captured by the image sensor, a feed mechanism for controlling the feed mechanism based on the amount of exposure analyzed by the image analyzer, and the portion of the different material exposed from the processing surface is ground, the grinding apparatus comprising:

Images