JP5275611B2 - Processing equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely confirm the type of a tool mounted to a device by its size, and to safely operate the device by detecting a replacement mistake in advance. <P>SOLUTION: When a grinding unit 40B is moved in an outside direction of a turn table 35 from a reference point P along an inter-shaft direction, an outer peripheral surface 48a of a grindstone fixation part 48 of a grinding wheel 45 abuts on a cam rod 113 of a tool detector 110, and the cam rod 113 rotates. Rotation of the cam rod 113 at a predetermined angle is detected by a sensor 114, and whether the outer diameter of a grindstone part 49A of the grinding wheel 45 is appropriate is determined based on moving distances d1, d2, ... of the grinding unit 40B from the reference point P to cam rod detection. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a processing apparatus such as a grinding apparatus that grinds the back surface of a semiconductor wafer, and more particularly, to a processing apparatus of a type in which a processing tool can be changed in various sizes.

  Semiconductor devices have been required to be thinner in response to demands for reduction in size, thickness, and size of various electronic devices to be mounted, and semiconductor wafers have also been made thinner. Thinning of a semiconductor wafer is generally performed by grinding the back surface of the semiconductor wafer. For example, when performing an additional process such as attaching a metal film to the back surface of the wafer after thinning, the wafer machine There is a risk of cracking due to insufficient strength. Therefore, a technique is known in which only the device forming region is thinned by grinding only the region on the back surface corresponding to the circular device forming region on which the semiconductor device is formed on the front surface with a grinding wheel (patent) Reference 1 etc.).

  In this way, the wafer in which only the device formation region is thinned has a recess formed on the back surface, and an annular protrusion protruding to the back surface is formed on the outer periphery around the recess with the original thickness remaining. . According to this wafer, since the annular convex portion serves as a reinforcing portion and rigidity is secured, the additional process can be performed safely and appropriately.

JP 2007-19379 A

  Generally, a mark indicating the crystal orientation of a material such as silicon is formed on the outer periphery of a wafer. Typical marks include V-shaped notches and orientation flats cut flat in the tangential direction. In order to maximize the number of semiconductor chips and increase production efficiency, the device formation area is required to have the maximum size while ensuring the width of the annular protrusion. The size (diameter) varies depending on the type. For this reason, as the grinding wheel for grinding only the device forming region, those having different outer diameters are prepared according to the device forming region to be ground, and those corresponding to the size of the device forming region are mounted on the grinding apparatus.

  By the way, the operation | work which mounts a grinding wheel to a grinding device is mostly manual. Therefore, there is a possibility that a replacement error such as an operator selecting and mounting a grinding wheel of an inappropriate size may occur. If the operation is started with different types of grinding wheels attached, the wafer and the grinding wheel itself may be damaged, which is a problem to be avoided. In addition, in order to maintain grinding efficiency and processing quality, there are types that grind in multiple stages, such as rough grinding followed by finish grinding. In such grinding equipment, replacement is possible. Incidence of mistakes increases. In order to prevent the occurrence of replacement mistakes, it is necessary to rely on the operator's own alerting and confirmation work, and therefore a method that can confirm the type of grinding wheel more reliably has been desired.

  Therefore, according to the present invention, the type of tool (grinding wheel, etc.) installed in the apparatus can be reliably confirmed according to the size, and even if there is a mistake in replacement, it is prevented from being operated as it is and safe. An object of the present invention is to provide a processing apparatus capable of operating the apparatus.

The processing apparatus of the present invention is a flat device for holding a wafer having a circular device forming region having a plurality of semiconductor devices formed on the front surface and an outer peripheral surplus region surrounding the device forming region in a state where the back surface is exposed. Holding means having a holding surface and a rotating shaft disposed opposite to the holding surface and extending in a direction substantially perpendicular to the holding surface, and the tool is detachably mounted on the rotating shaft. Processing means for processing only the back surface corresponding to the device formation region of the wafer held on the surface, feed means for processing and feeding the processing means toward the wafer held on the holding surface, and the processing means on the holding surface A tool that moves relative to a direction parallel to the rotation axis, the tool being concentric with the rotating shaft, and a cylindrical outer peripheral surface, and an end surface facing the holding surface and substantially parallel to the holding surface Have A stone fixing portion, and an annular grindstone portion that is fixed to an end surface of the grindstone fixing portion and has an outer diameter substantially the same diameter as the cylindrical outer peripheral surface, and the processing means is parallel to the holding surface by the moving means. Detecting means for detecting the outer diameter position of the grindstone fixing portion by contact with the cylindrical outer peripheral surface of the grindstone fixing portion at an arbitrary position when moving relative to the direction, and the outside of the grindstone fixing portion detected by the detecting means. Discriminating means for discriminating the type of tool on the basis of the radial position, and the detecting means is arranged on the moving path of the processing means by the relative movement so as to be horizontally rotatable, and the cylindrical outer periphery of the grindstone portion A cam rod that rotates when the surface comes into contact with it, and a sensor that detects the cam rod that has rotated, and the determination unit is configured to detect the sensor from a reference point set in the middle of the movement path of the processing unit. Until the cam rod is detected Based on the outer diameter of the grinding wheel portion which is determined in accordance with the movement distance of the processing means is characterized by determining the type of the tool.

  In the processing apparatus of the present invention, the processing means is processed and fed by the feeding means toward the back surface of the wafer held on the holding surface of the holding means, and the tool is applied to the back surface corresponding to the device formation region, thereby causing the wafer to be processed. Processing is applied. The processing position on the wafer by the tool, that is, the processing region by the grindstone is adjusted by moving the processing means in a direction parallel to the holding surface by the moving means. An appropriate tool is selected according to the size of the wafer, the type of processing, conditions, etc., and is attached to the rotating shaft. As the tool for processing the device forming region, a tool whose outer diameter of the grindstone corresponds to the radius of the device forming region is appropriate.

  The diameter of the grindstone part is an element for discriminating the type of the tool.In the processing apparatus of the present invention, the moving means is relatively moved in the direction parallel to the holding surface by the moving means, and the outer diameter position of the grindstone fixing part of the tool is determined. By detecting with a detection means, it can be confirmed whether the tool provided with the grindstone part of a suitable diameter is mounted | worn. In the grindstone fixing portion of the present invention, an annular grindstone portion for processing a wafer is provided on the end surface, and the cylindrical outer peripheral surface has substantially the same diameter as the outer diameter of the grindstone portion. The detection means of the present invention does not directly contact the outer diameter of the grindstone portion to detect the outer diameter position, but contacts the outer peripheral surface of the grindstone fixing portion that is substantially concentric with the same diameter as the grindstone portion. It is assumed that the outer diameter position of the part has been detected. Whether or not the outer diameter of the tool is appropriate is determined by the determining means based on the outer diameter position of the grindstone fixing portion detected by the detecting means.

According to the present invention, there is no crack layer between the plurality of composite layers (modified layer + crack layer) formed in the wafer by the first laser beam irradiation step, but the crystal extending from the crack layer Even if the laser beam is irradiated due to the influence of defects or the like, multiphoton absorption is not performed, and an altered layer is difficult to form. However, the effect | action which extends the crack layer extended from the already existing altered layer by irradiation of a laser beam is anticipated. In the second laser beam irradiation step, the non-crack layer is irradiated with a laser beam, and the crack layer is stretched to the deteriorated layer of the adjacent composite layer. As a result, the crack layer can reach the altered layer. For this reason, when a wafer is cleaved in the wafer cleaving process, the cleaving can be performed easily and smoothly, and no cleaving failure is caused. In the present invention, by performing the second laser beam irradiation step, the number of altered layers formed by the first laser beam irradiation step can be reduced, and the total number of laser beam irradiations by both steps is also as follows. This can be reduced from the conventional number of times of laser beam irradiation that can be cleaved. For this reason, a decrease in processing efficiency can be suppressed.

  According to the present invention, the type of tool attached to the apparatus can be reliably confirmed according to the size, and even if there is a replacement error, it is prevented from being operated as it is, and the apparatus can be operated safely. The effect that it can be made.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[1] Semiconductor Wafer Reference numeral 1 in FIG. 1 is a disk-shaped semiconductor wafer ground on the back surface in this embodiment. The wafer 1 is a silicon wafer or the like, and a plurality of rectangular semiconductor chips (devices) 3 are partitioned on a surface 1 a by grid-like division lines 2. An electronic circuit (not shown) such as an IC or an LSI is formed on the surface of the semiconductor chip 3.

  The plurality of semiconductor chips 3 are formed in a substantially circular device formation region 4 concentric with the wafer 1. The device forming region 4 occupies most of the wafer 1, and the outer periphery of the wafer 1 around the device forming region 4 is an annular outer peripheral region 5 in which the semiconductor chip 3 is not formed. A V-shaped notch 6 is formed at a predetermined location on the outer peripheral surface of the wafer 1 as a mark indicating the crystal orientation of the semiconductor. The notch 6 is formed in the outer peripheral surplus region 5.

  The thickness of the wafer 1 is about 700 μm, for example. As shown in FIG. 2A, the wafer 1 has a circular recess 4A in which only a region corresponding to the device formation region 4 on the back surface 1b is removed by a predetermined thickness. Is formed, and an annular convex portion 5A in which the original thickness remains in the outer peripheral surplus region 5 around the concave portion 4A is formed. By forming the recess 4A, the device formation region 4 is thinned to the thickness of the semiconductor chip 3 to be obtained (for example, about 50 to 100 μm). The recess 4A of the wafer 1 shown in FIG. 2A is formed concentrically with the wafer 1 itself.

  FIG. 2B shows a wafer in which a concave portion 4A is formed on the back surface 1b and an annular convex portion 5a is formed around the concave portion 4A. The mark indicating the crystal orientation of the wafer 1 is on the outer peripheral portion. The orientation flat 7 is a notch formed flat in the tangential direction. In the wafer 1 in which the orientation flat 7 is formed, the recess 4A is formed avoiding the orientation flat 7, and therefore the recess 4A is eccentric with respect to the center of the wafer 1. When the amount of defects from the outer peripheral edge of the notch 6 and the orientation flat 7 is compared, the orientation flat 7 has a larger amount. Therefore, when the outer diameter of the wafer 1 is the same, the inner diameter of the recess 4A is the wafer on which the notch 6 is formed. 1 is larger than the wafer 1 on which the orientation flat 7 is formed.

  The recess 4A on the back surface of the wafer 1 is formed by grinding the back surface side of the device forming region 4. The code | symbol 20 of FIG. 3 has shown an example of the grinding apparatus suitable for implementing grinding which forms the recessed part 4A. Before the wafer 1 is supplied to the grinding apparatus 20, a protective tape 8 is attached to the entire surface 1a on which the semiconductor chips 3 are formed for the purpose of protecting electronic circuits. The protective tape 8 has a structure in which an adhesive of about 5 to 20 μm is applied to one surface of a soft resin base sheet such as polyolefin having a thickness of about 70 to 200 μm, and the adhesive is used as the surface 1 a of the wafer 1. It is pasted according to.

[2] Grinding device The grinding device 20 will be described with reference to FIGS. According to this grinding apparatus 20, the surface 1 a side of the wafer 1 is attracted to the vacuum suction chuck table (holding means) 30 via the protective tape 8 to hold the wafer 1, and two grinding units (coarse) The concave portion 4A is formed on the back surface 1b by grinding and finishing grinding) 40A and 40B, and the bottom surface of the concave portion 4A is finished flat.

  As shown in FIG. 3, the grinding apparatus 20 has a rectangular parallelepiped base 21, and the wafer 1 is placed on a surface 1 a in a supply cassette 22 </ b> A that is detachably set at a predetermined position on the base 21. A plurality are accommodated in a stacked state with the side up. One wafer 1 accommodated in the supply cassette 22A is pulled out by the transfer robot 23, turned upside down, and then placed on the positioning table 24 with the back surface 1b facing upward. The position is determined.

  A turntable 35 that is rotationally driven in the R direction is provided on the base 21, and a plurality of (in this case, three) disk-shaped chuck tables 30 are provided on the outer periphery of the turntable 35. Are arranged at equal intervals in the circumferential direction. These chuck tables 30 are rotatably supported with the Z direction (vertical direction) as a rotation axis, and are driven to rotate by a drive mechanism (not shown).

  The wafer 1 that has been positioned on the positioning table 24 is picked up from the positioning table 24 by the supply arm 25, and the surface 1a side to which the protective tape 8 is stuck is placed on one chuck table 30 that is vacuum operated. It is placed concentrically in the state of facing.

  As shown in FIG. 4B, the chuck table 30 has a circular suction part 32 formed of a porous member at the center upper part of a frame 31, and the wafer 1 has a horizontal upper surface of the suction part 32. The protective tape 8 is in close contact with a certain holding surface 32a, and is attracted and held in a state where the back surface 1b is exposed upward. The electronic circuit of the semiconductor chip 3 on the front surface 1 a side of the wafer 1 is protected by the protective tape 8 and is prevented from being damaged from the chuck table 30.

  The wafer 1 held on the chuck table 30 is fed to a primary processing position below the rough grinding unit 40A when the turntable 35 rotates by a predetermined angle in the R direction (clockwise direction), and is ground at this position. The back surface 1b is roughly ground by the unit 40A to form the recess 4A. Next, the turntable 35 is again rotated by a predetermined angle in the R direction to feed the wafer 1 to a secondary machining position below the finish grinding unit 40B. At this position, the bottom surface of the recess 4A is finished by the grinding unit 40B. To be ground.

  Each of the grinding units 40A and 40B has the same configuration, and is distinguished by the fact that the grindstones to be mounted are different for rough grinding and finish grinding. As shown in FIG. 4, the grinding units 40A and 40B include a cylindrical spindle housing 41 whose axial direction extends in the Z direction, and a spindle shaft (rotating shaft) that is coaxially and rotatably supported in the spindle housing 41. ) 42, a motor 43 that is fixed to the upper end of the spindle housing 41 and rotationally drives the spindle shaft 42, and a flange 44 that is coaxially fixed to the lower end of the spindle shaft 42. A grinding wheel 45 is detachably attached to the flange 44.

  As shown in FIGS. 4 and 6, the grinding wheel 45 includes a frame 46 and a plurality of grindstones 49 fixed to the frame 46. The frame 46 is formed with a conical conical portion 47b which is reduced in diameter as it goes downward at the lower end of the upper flange mounting portion 47a having a uniform outer diameter. Further, the outer diameter is uniform at the lower end of the conical portion 47b. An annular grindstone fixing portion 48 is formed.

  The grindstone fixing portion 48 has a cylindrical outer peripheral surface 48 a and an end surface 48 b that faces the holding surface 32 a of the chuck table 30. The end surface 48b is parallel to the holding surface 32a, and a plurality of chip-shaped grindstones 49 are annularly arranged and fixed to the end surface 48b. A plurality of grindstones 49 form an annular grindstone portion 49 </ b> A, and the outer diameter of the grindstone portion 49 </ b> A (the grinding outer diameter of the grinding wheel 45) is formed substantially the same as the outer diameter of the outer peripheral surface 48 a of the grindstone fixing portion 48. . The grinding wheel 45 is selected so that the outer diameter of the grindstone 49 </ b> A corresponds to the radius of the recess 4 </ b> A formed on the back surface 1 b of the wafer 1, i.e., the radius of the device formation region 4. The cutting edge surface which is the lower end surface of the grindstone 49 is set in parallel with the end surface 48b of the grindstone fixing portion 48, that is, in parallel with the holding surface 32a. As the grindstone 49, for example, diamond abrasive grains mixed in a glassy bond material, molded, and sintered are used.

  The grindstone 49 fixed to the grindstone fixing portion 48 is used for rough grinding and finish grinding, and the grinding wheel 45 in which the grindstone 49 is used for rough grinding is mounted on a grinding unit 40A for rough grinding. Further, the grinding wheel 45 in which the grindstone 49 is used for finish grinding is mounted on a grinding unit 40B for finish grinding. As the grindstone 49 for rough grinding, for example, one containing relatively coarse abrasive grains of about # 320 to # 600 is used. Further, as the grindstone 49 attached to the grinding unit 40B for finish grinding, for example, a grindstone containing relatively fine abrasive grains of about # 2000 to # 8000 is used. Each of the grinding units 40A and 40B is provided with a grinding water supply mechanism (not shown) for supplying grinding water for cooling and lubrication of the grinding surface or discharging grinding debris.

  As shown in FIG. 3, each of the grinding units 40 </ b> A and 40 </ b> B is attached to a front surface 26 a of a pair of left and right columns 26 arranged in the X direction that is erected at the end of the base 21 on the back side in the Y direction. . The mounting structure of each grinding unit 40A, 40B with respect to each column 26 is the same and is symmetrical in the X direction.

  The front surface 26a on the front side in the Y direction of each column 26 is a vertical surface with respect to the upper surface of the base 21, but tapers back obliquely at a predetermined angle from the center in the X direction toward the end. Formed on the surface. The horizontal direction of the taper surface 26a, that is, the taper direction, is the position of the chuck table 30 positioned at the corresponding front machining position (the left primary machining position in the left column 26 and the right secondary machining position in the right column 26). It is set to be parallel to a line connecting the rotation center and the rotation center of the turntable 35.

  As shown in FIGS. 3 and 5, the taper surface 26 a of each column 26 is provided with a pair of upper and lower guides 51 parallel to the taper direction, and the X-axis slider 52 slides on the guides 51. It is installed freely. The X-axis slider 52 is reciprocated along the guide 51 by a ball screw type feed mechanism (not shown) driven by a servo motor 53. The reciprocating direction of the X-axis slider 52 is parallel to the direction in which the guide 51 extends, that is, the taper direction of the tapered surface 26a.

  The front surface of the X-axis slider 52 is a surface along the X / Z direction, and the grinding units 40A and 40B are installed on the front surface so as to be movable up and down in the Z direction (vertical direction). These grinding units 40 </ b> A and 40 </ b> B are slidably mounted via a Z-axis slider 55 on a guide 54 that extends in the Z direction and is provided on the front surface of the X-axis slider 52. Each grinding unit 40A, 40B is moved up and down in the Z direction via a Z-axis slider 55 by a ball screw type feed mechanism 57 driven by a servo motor 56.

  As described above, the direction connecting the rotation center of each chuck table 30 positioned at the primary processing position and the secondary processing position and the rotation center of the turntable 35 (the direction indicated by F in FIG. Are referred to as the taper direction of the front surface 26a of the column 26, that is, the direction in which the guide 51 extends. In each of the grinding units 40A and 40B, the rotation center of the grinding wheel 45 (axial center of the spindle shaft 42) corresponds to the corresponding machining position (primary machining position in the grinding unit 40A for rough grinding, and in the grinding unit 40B for finishing. The positions are set so as to exist directly in the inter-axis direction connecting the rotation center of the chuck table 30 and the rotation center of the turntable 35 positioned at the secondary processing position). Therefore, when the grinding units 40A and 40B move along the guide 51 together with the X-axis slider 52, the rotation center of the grinding wheel 45 is set to move along the inter-axis direction.

  In forming the recess 4A by grinding only the region corresponding to the device formation region 4 on the back surface 1b of the wafer 1, the position between the axes of the grinding unit 40A (40B) is as shown in FIGS. The grinding outer diameter of the grinding wheel 45 facing the back surface 1b of the wafer 1 positioned at each processing position (the outer diameter of the grinding wheel portion 49A) is positioned at a recess forming position corresponding to the radius of the device forming region 4 of the wafer 1. . This recess formation position is a position where the cutting edge surface of the grindstone 49 passes through the vicinity of the rotation center of the wafer 1 and the outer periphery of the device formation region 4. In this case, it is the outer periphery side of the turntable 35 with respect to the rotation center of the wafer 1. The

  When the axial direction of the grinding unit 40A (40B) is determined in this way, the chuck table 30 is rotated to rotate the wafer 1, and the feed unit 57 rotates while feeding the grinding unit 40A (40B) downward. A grinding operation for pressing the grindstone 49 of the grinding wheel 45 against the back surface 1b of the wafer 1 is started.

  By rough grinding by the grinding unit 40A at the primary processing position, a recess 4A is formed on the back surface 1b of the wafer 1 in a region corresponding to the device formation region 4 as shown in FIG. 2, and an annular shape is formed around the recess 4A. A convex portion 5A is formed. Further, the bottom surface of the recess 4A is finish-ground by finish grinding by the grinding unit 40B at the secondary processing position. In the rough grinding, for example, the thickness after finish grinding is ground to a thickness of about 20 to 40 μm, and in the finish grinding, the remaining thickness is ground, whereby the thickness of the semiconductor chip 3 to obtain a region corresponding to the device formation region 4 is obtained. It is thinned.

  As shown in FIG. 2 and FIG. 4A, the grinding striations 9 having a pattern in which a large number of arcs are radially drawn remain on the surface to be ground after rough grinding. The grinding striation 9 is a trajectory of crushing processing by abrasive grains in the grindstone 49, and is a mechanical damage layer including microcracks and the like. Although the grinding striation 9 by rough grinding is removed by finish grinding, a new grinding striation may remain even by finish grinding.

  When grinding the wafer 1, in both rough grinding and finish grinding, the wafer thickness is measured one after another by a contact-type thickness measuring device 60 provided in the vicinity of each processing position, and based on the measured value. The grinding amount is controlled. As shown in FIG. 4A, the thickness measuring device 60 is configured by a combination of a reference side height gauge 61 and a movable side height gauge 62.

  Each of the height gauges 61 and 62 is provided with probes 61 a and 62 a, the probe 61 a of the reference side height gauge 61 contacts the surface 31 a of the frame 31 of the chuck table 30, and the probe 62 a of the movable side height gauge 62 is covered with the wafer 1. It is set so as to contact the grinding surface. The thickness measuring device 60 outputs the measured thickness value of the wafer 1 by comparing the height positions of the contact points of the probes 61a and 62a. The measurement point when the thickness of the device formation region 4 is measured by forming the recess 4A, that is, the contact point of the probe 61a of the movable height gauge 61 is the outer periphery of the recess 4A as shown by the broken line in FIG. Part is preferred.

  The wafer 1 on which the formation of the concave portion 4A is completed by grinding as described above is collected as follows. First, the finishing grinding unit 40B is raised and retracted from the wafer 1, while the turntable 35 is rotated by a predetermined angle in the R direction so that the wafer 1 is mounted on the chuck table 30 from the supply arm 25. Return to position. The vacuum operation of the chuck table 30 is stopped at this attachment / detachment position, and then the wafer 1 is transferred to the spinner type cleaning device 28 by the recovery arm 27 and cleaned.

  In the cleaning unit 28, the wafer 1 is sucked and held on a rotary suction table having the same diameter as the wafer 1, and cleaning water such as pure water is dropped near the center of the wafer 1 while rotating at about 1000 rpm. The back side is cleaned. Thereafter, dry air is blown and dried while the rotational speed is increased to about 2000 to 3000 rpm. The wafer 1 cleaned by the cleaning unit 28 is transferred and accommodated in the collection cassette 22B by the transfer robot 23.

[3] Tool Detection Device The basic configuration and operation of the grinding device 20 have been described above. Next, an embodiment of the tool detection device according to the present invention will be described.

[3-1] First Embodiment As shown in FIG. 3, the tool of the first embodiment is provided on the base 11 between the column 26 and the turntable 35 to which the finish grinding side grinding unit 40 </ b> B is attached. A detection device 110 is provided.

  As shown in FIG. 7, the tool detection device 110 includes a fixed base 111 fixed to the base 11, and a boomerang-shaped cam rod 113 is provided on the fixed base 111 via a rotating shaft 112 extending in the vertical direction. Is supported so that it can swivel horizontally. The cam rod 113 is bent in a horizontal plane, the protruding side of the central bent portion is directed to the front side in the Y direction, and the upper end portion of the rotating shaft 112 is fixed to the bent portion.

  The inner end 113a of the cam rod 113 is on the moving path when the grinding unit 40B moves in the outer direction (F1 direction) of the turntable 35 along the inter-axis direction (indicated by F1-F2). The outer peripheral surface 48a of the grindstone fixing portion 48 of the wheel 45 is disposed at a position where it can abut. When the grinding unit 40B further moves in the F1 direction after the grindstone fixing portion 48 comes into contact with the inner end portion 113a, the inner end portion 113a is pushed by the grindstone fixing portion 48 and the cam rod 113 rotates in the R1 direction.

  As the grinding unit 40B moves in the F1 direction, the outer end 113b of the cam rod 113 is detected by the sensor 114 when the cam rod 113 rotates a predetermined angle in the R1 direction. The sensor 114 is an optical sensor such as a photocoupler, and is fixed to the fixed base 111 via a fixed stand 115. The optical path of the sensor 114 is interrupted by the outer end 113b of the cam rod 113 that has turned in the R1 direction. When the interruption is "sensor ON", a detection signal indicating that is shown in FIG. To be supplied.

  As described above, the grinding unit 40B moves in the inter-axis direction along the guide 51 together with the X-axis slider 52, but an appropriate position in the middle of the movement path is set as a reference point. The discriminating means 140 recognizes the position of the reference point. Further, the moving distance data of the grinding unit 40B from the reference point until the sensor 114 detects the outer end 113b of the cam rod 113 is supplied as the “detection distance” to the determination means 140. And the discrimination means 140 has memorize | stored the outer diameter of 49 A of grindstone parts according to detection distance, ie, the kind of grinding wheel 45. FIG. The moving distance data and the reference point can be detected and set using, for example, a rotary encoder provided in a servo motor 53 that drives the grinding unit 40B in the inter-axis direction.

  A cylinder 116 is connected to the outer end 113b of the cam rod 113 to return the cam rod 113 to the initial position depicted by the solid line in FIG. The cylinder 116 is disposed so that the piston 116b extends and contracts from one end of the cylinder body 116a toward the front side in the Y direction, and the tip of the piston 116b is connected to the outer end 113b of the cam rod 113 via the link 117b. It is pin-coupled so that it can rotate horizontally. The cylinder main body 116a is pin-coupled to a stay 118 standing on the fixed base 111 via a link 117a so as to be horizontally rotatable. When the cam rod 113 rotates in the R1 direction from the initial position, the piston 116b expands. However, the piston 116b always works to contract, so that the cam rod 113 is rotated in the R2 direction by the cylinder 116 and returned to the initial position. It is energized.

  In the grinding apparatus 10, the grinding wheel 45 attached to the flange 44 by the tool detection apparatus 110 is an appropriate one before performing the grinding operation of the wafer back surface (for example, before taking out the wafer 1 from the supply cassette 22 </ b> A). The operation for confirming whether or not there is is performed as follows.

  First, in performing the confirmation operation, the outer diameter of the grindstone portion 49A of the grinding wheel 45 is input to the discriminating unit 140 as data for identifying the type of the grinding wheel 45 that appropriately forms the diameter of the recess 4A to be obtained. . Next, the grindstone diameter confirmation mode is selected from the operation panel of the grinding apparatus 20.

  The grinding unit 40B is positioned on the inner peripheral side of the turntable 35 with respect to the reference point or the reference point, and the grinding unit 40B is moved from the position along the axis direction toward the tool detection device 110 (F1 direction). . Then, the outer peripheral surface 48a of the grindstone fixing portion 48 of the grinding wheel 45 comes into contact with the inner end portion 113a of the cam rod 113 at the initial position, and the inner end portion 113a is pushed by the grindstone fixing portion 48 so that the cam rod 113 is R1. Rotate in the direction. Further, when the grinding unit 40B moves in the F1 direction, the sensor 114 detects the outer end 113b of the rotating cam rod 113. A signal indicating that the outer end 113b has been detected by the sensor 114 is supplied to the discriminating means, and the movement of the grinding unit 40B stops at this point.

  The determination unit 140 is supplied with the movement distance data of the grinding unit 40B from the reference point to the time when the sensor 114 detects the cam rod 113. The detection distance based on the movement distance data is shorter as the outer diameter of the grindstone fixing portion 48 for rotating the cam rod 113, that is, the outer diameter of the grindstone portion 49A is larger.

  FIG. 8A shows a state where the grinding unit 40B, to which the grinding wheel 45 having the grindstone fixing portion 48 having the outer diameter D1 is mounted, has moved from the reference point P to the position where the cam rod 113 turns on the sensor 114. The detection distance at this time is d1. 8B shows a position where the cam rod 113 turns on the sensor 114 from the reference point P in the grinding unit 40B to which the grinding wheel 45 having the grindstone fixing portion 48 having the outer diameter D2 smaller than D1 is mounted. The detection distance at this time is d2 longer than d1.

  The discriminating means 140 has an outer diameter (D1, D2,...) Of the grindstone portion 49A corresponding to the stored detection distance (d1, d2,...) And a grindstone portion 49A of an appropriate grinding wheel 45 inputted in advance. Are compared with each other, and if both match, it is determined that the grinding wheel 45 attached to the grinding unit 40B is appropriate. For example, when the outer diameter D1 of the grindstone fixing portion 48 is input to the discriminating means 140 as an appropriate grinding wheel 45 in advance and the grinding wheel 45 having the outer diameter D1 of the grindstone fixing portion 48 is actually mounted, the detection distance Becomes d1, and the discriminating means 140 collates the outer diameter D1 of the grindstone fixing portion 48 corresponding to d1 with the inputted outer diameter D1 of the grindstone fixing portion 48. In this case, since D1 = D1, it is determined that the grinding wheel 45 is appropriate.

  Thereafter, the control system of the apparatus is informed that the grinding can be started, the wafer 1 is taken out from the supply cassette 22A and held on the chuck table 30, washed through rough grinding and finish grinding, and then transferred to the recovery cassette 22B. A series of grinding operations such as housing is started.

  On the other hand, when the outer diameter of the grinding wheel portion 49A corresponding to the detected distance does not match the outer diameter of the grinding wheel portion 49A of an appropriate grinding wheel 45 input in advance, the mounted grinding wheel 45 is It is determined that it is inappropriate, that is, a replacement error has occurred. For example, when the outer diameter D1 of the grindstone fixing portion 48 is input to the discriminating means 140 as an appropriate grinding wheel 45 in advance, and when the grinding wheel 45 having the outer diameter of the grindstone fixing portion 48 is actually mounted, The detection distance is d2, and the determination unit 140 collates the outer diameter D2 of the grindstone fixing portion 48 corresponding to d2 with the input outer diameter D1 of the grindstone fixing portion 48. In this case, since D2 ≠ D1, it is determined that the grinding wheel 45 is inappropriate.

  If it is determined that the grinding wheel 45 is inappropriate, a warning sound is emitted, and the grinding wheel 45 is replaced with an appropriate grinding wheel 45. After the grinding wheel 45 is replaced, the above-described detection operation is performed, and the tool detection device 110 confirms the grinding wheel 45 again. After confirming that the grinding wheel 45 is appropriate, the grinding operation is started.

  Although not shown in FIG. 3, the tool detection device 110 is also arranged corresponding to the grinding unit 40A on the rough grinding side. The tool detection device corresponding to the grinding unit 40A is configured to be bilaterally symmetric with the tool detection device 110 corresponding to the grinding unit 40B, and the above detection operation is performed in exactly the same manner, and the grinding mounted on the grinding unit 40A. It is confirmed whether or not the wheel 45 is appropriate.

  According to the tool detection apparatus 110 of the first embodiment, it is accurately determined whether or not the mounted grinding wheel 45 is appropriate. If there is a replacement error, the error is detected before grinding. I can know for sure. Conventionally, the grinding wheel 45 to be mounted is mounted on the flange 44 after confirming that the worker is appropriate. At that time, the outer diameter of the grindstone portion 49A of the mounted grinding wheel 45 is fixed. Even if it is inappropriate, the grinding operation may be started as it is. However, in this embodiment, since the outer diameter of the grindstone portion 49A of the grinding wheel 45 is confirmed by the tool detection device 110 before grinding, it is possible to know that the grinding wheel 45 is inappropriate before grinding. A suitable grinding wheel 45 can be replaced. As a result, no troubles such as breakage of the wafer 1 occur during grinding, and the apparatus can be operated safely.

[3-2] Second Embodiment FIG. 9 shows a tool detection device 120 in a form similar to the present invention (hereinafter referred to as a second embodiment) . This tool detection device 120 includes a pulse-type or resistance-type linear scale 123 supported on a fixed base 121 fixed to the base 11 via a stand 122, and an axial direction (F1-F2). Sensor plate 124 mounted so as to be movable along the direction). A cylinder 126 is supported on the fixed base 121 via a bracket 125. The cylinder 126 includes a cylinder main body 126a fixed to the bracket 125 and a piston 126b extending from the cylinder main body 126a in the F2 direction, and a sensor plate 124 is fixed to the tip of the piston 126b. The sensor plate 124 that is movable in the inter-axis direction is urged in the F2 direction by the cylinder 126 and returned to the initial position indicated by the solid line. The linear scale 123 detects the moving distance of the sensor plate 124 that has moved in the F1 direction from the initial position.

  When a detection operation is performed to move the grinding unit 40B in the outer direction of the turntable 35 along the inter-axis direction, the outer peripheral surface 48a of the grindstone fixing portion 48 comes into contact with the front end 124a of the sensor plate 124, and the sensor plate 124 is F1. Move in the direction. As shown in FIG. 11, in the detection operation in the second embodiment, the grinding unit 40 </ b> B is moved from the reference point P by a certain distance d in the outer direction of the turntable 35 along the inter-axis direction. This distance d is set to such a distance that the outer peripheral surfaces 48a of the grindstone fixing portions 48 of all of the plural types of grinding wheels 45 used are in contact with the sensor plate 124 at the initial position, and the sensor plate 124 moves a certain distance. Is done. That is, the distance d is set such that the sensor plate 124 with which the grindstone fixing portion 48 abuts can move from the initial position even if the grindstone fixing portion 48 has the smallest diameter.

  In the second embodiment, the movement distance of the sensor plate 124 detected by the linear scale 123 is supplied to the determination unit 140 shown in FIG. The moving distance of the sensor plate 124 detected by the linear scale 123 is supplied to the determination unit 140 as a “detection distance”. And the discrimination means 140 has memorize | stored the outer diameter of 49 A of grindstone parts according to detection distance, ie, the kind of grinding wheel 45. FIG.

  In the second embodiment, the grinding unit 40B is moved a certain distance (distance d in FIG. 11) in the tool detection device 120 direction (F1 direction) along the inter-axis direction from the reference point. In the middle of the movement, the outer peripheral surface 48a of the grindstone fixing portion 48 of the grinding wheel 45 abuts on the tip 124a of the sensor plate 124 at the initial position, and the sensor plate 124 is pushed by the grindstone fixing portion 48, It moves in the F1 direction by a distance corresponding to the outer diameter of the.

  The determination unit 140 is supplied with the moving distance of the sensor plate 124, that is, the detection distance. The detection distance is longer as the outer diameter of the grindstone fixing portion 48 that contacts the sensor plate 124 and moves in the F1 direction, that is, the outer diameter of the grindstone portion 49A is larger.

  FIG. 11A shows a state where the grinding unit 40B, to which the grinding wheel 45 having the grindstone fixing part 48 having the outer diameter D1 is mounted, has moved the distance d from the reference point P, and the detection distance at this time is d1. It is. FIG. 11B shows a state where the grinding unit 40B, to which the grinding wheel 45 having the grindstone fixing portion 48 having an outer diameter D2 smaller than D1 is mounted, has moved a distance d from the reference point P. The detection distance at this time is d2 shorter than d1.

  The discriminating means 140 has an outer diameter (D1, D2,...) Of the grindstone portion 49A corresponding to the stored detection distance (d1, d2,...) And a grindstone portion 49A of an appropriate grinding wheel 45 inputted in advance. Are compared with each other, and if both match, it is determined that the grinding wheel 45 attached to the grinding unit 40B is appropriate. On the other hand, when the outer diameter of the grinding wheel portion 49A corresponding to the detected distance does not match the outer diameter of the grinding wheel portion 49A of an appropriate grinding wheel 45 input in advance, the mounted grinding wheel 45 is Determine that it is inappropriate. This determination operation is the same as that in the first embodiment.

[3-3] Third Embodiment FIG. 10 shows a tool detection device 130 in a form similar to the present invention (hereinafter referred to as a third embodiment) . This tool detection device 130 has a cam rod 133 similar to the cam rod 113 of the first embodiment. The cam rod 133 is supported by a fixed base 131 fixed to the base 21 through a rotary shaft 132 so as to be horizontally rotatable. The upper end portion of the rotating shaft 132 protrudes from the cam rod 133, and at the protruding end portion, the rotating cam rod 133 is rotated in the R2 direction to return to the initial position indicated by the solid line, and the rotation angle of the cam rod 133 is set. A pulse-type or resistance-type rotary scale 135 for detection is mounted. Note that the cam rod 133 may be returned to the initial position by a motor instead of the rotary cylinder 134.

  When a detection operation for moving the grinding unit 40B in the outer direction of the turntable 35 along the inter-axis direction is performed, the outer peripheral surface 48a of the grindstone fixing portion 48 comes into contact with the inner end portion 133a of the cam rod 133, and the cam rod 133 is R1. Rotate in the direction. Also in the third embodiment, as in the second embodiment, the grinding unit 40B is moved from the reference point along the inter-axis direction by a fixed distance (corresponding to the distance d in FIG. 11) in the outer direction of the turntable 35. . This fixed distance is a distance by which the outer peripheral surface 48a of the grindstone fixing portion 48 of all of the plural types of grinding wheels 45 used contacts the cam rod 133 and the cam rod 133 rotates by a certain angle, in other words, the grindstone having the smallest diameter. Even the fixed portion 48 is the distance that the cam rod 133 can be rotated by the grindstone fixing portion 48.

  In the second embodiment, the rotation angle of the cam rod 133 detected by the rotation scale 135 is supplied to the determination unit 140 shown in FIG. The rotation angle of the cam rod 133 detected by the rotation scale 135 is supplied to the determination unit 140 as a “detection angle”. And the discrimination means 140 has memorize | stored the outer diameter of 49 A of grindstone parts according to a detected angle, ie, the kind of grinding wheel 45. FIG.

  In the third embodiment, the grinding unit 40B is moved from the reference point by a fixed distance in the tool detection device 130 direction (F1 direction) along the inter-axis direction (F1-F2 direction). In the middle of the movement, the outer peripheral surface 48a of the grindstone fixing portion 48 of the grinding wheel 45 abuts on the inner end portion 133a of the cam rod 133 at the initial position, and the cam rod 133 is pushed by the grindstone fixing portion 48, and the grindstone fixing portion. It rotates in the R1 direction at an angle corresponding to the outer diameter of 48.

  The rotation angle of the cam rod 133 detected by the rotation scale 135 is supplied to the determination unit 140. The rotation angle of the cam rod 133 is larger as the outer diameter of the grindstone fixing portion 48 that moves the cam rod 133 in the R1 direction, that is, the outer diameter of the grindstone portion 49A is larger. The discriminating means 140 collates the outer diameter of the grindstone portion 49A corresponding to the stored detected angle with the outer diameter of the grindstone portion 49A of the appropriate grinding wheel 45 input in advance, and when both match, Determines that the grinding wheel 45 attached to the grinding unit 40B is appropriate. On the other hand, when the outer diameter of the grinding wheel portion 49A corresponding to the detected angle does not match the outer diameter of the grinding wheel portion 49A of the appropriate grinding wheel 45 input in advance, the mounted grinding wheel 45 is It is determined that it is inappropriate.

  Even in the second embodiment and the third embodiment, as in the first embodiment, the type of tool mounted on the apparatus can be reliably confirmed by the size, and even if there is a replacement error, As a result, it is possible to prevent the grinding from being started as it is and to operate the apparatus safely. Moreover, although the tool detection apparatuses 120 and 130 of 2nd Embodiment and 3rd Embodiment respond | correspond to the grinding unit 40B on the finishing side, these tool detection apparatuses 120 and 130 are grinding units 40A on the rough grinding side. Corresponding to the above, the arrangement is symmetrical.

  In each of the above embodiments, the grinding wheel 45 for forming the recess 4A is cited. However, as the grinding wheel 45, the entire upper surface of the chuck table 30 is ground before the back surface grinding of the wafer 1 is performed. Self-cutting grinding wheels are also used. Also in such a grinding wheel, the diameter of the grindstone is confirmed by the tool detection device 110 (120, 130) of each of the above embodiments.

  The grinding wheel for self-cutting has a grinding wheel having a diameter larger than the radius of the chuck table 30, and if the grinding wheel 45 for forming recesses as described above is mounted, the entire surface of the chuck table 30 is ground. I can't. On the contrary, if the grinding wheel 45 for self-cutting is mounted when forming the recess, the entire back surface 1b of the wafer 1 is ground and the recess 4A is not formed. In the present embodiment, troubles due to such replacement mistakes can be avoided in advance, and an appropriate grinding wheel according to the grinding mode to be performed can be mounted.

It is the (a) perspective view and (b) side view of the wafer by which the back surface grinding is carried out by the grinding device concerning the embodiment of the present invention. It is a perspective view which shows the back surface side of the wafer in which the recessed part was formed by grinding. 1 is an overall perspective view of a grinding apparatus according to an embodiment. It is (a) perspective view and (b) side view which show the grinding unit of the grinding apparatus of FIG. It is a top view which shows the attachment structure of a grinding unit. It is a side view which shows the state which has formed the recessed part in the wafer back surface with the grinding unit. It is a perspective view which shows the tool detection apparatus of 1st Embodiment with which the grinding apparatus of FIG. 3 is provided. It is a side view which shows the effect | action which detects the outer diameter of a grindstone part by the tool detection apparatus of 1st Embodiment. It is a perspective view which shows the tool detection apparatus of 2nd Embodiment. It is a perspective view which shows the tool detection apparatus of 3rd Embodiment. It is a side view which shows the effect | action which detects the outer diameter of a grindstone part by the tool detection apparatus of 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Semiconductor wafer 1a ... Wafer surface 1b ... Wafer back surface 3 ... Semiconductor chip (device)
DESCRIPTION OF SYMBOLS 4 ... Device formation area 4A ... Recessed part 5 ... Periphery surplus area 5A ... Annular convex part 20 ... Grinding device 30 ... Chuck table (holding means)
32a ... Holding surface 40A, 40B ... Grinding unit (processing means)
42 ... Spindle (rotating shaft)
45 ... Grinding wheel (tool)
48 ... Grinding wheel fixing part 48a ... Outer peripheral surface of the grinding wheel fixing part 48b ... End face of the grinding wheel fixing part 49A ... Grinding wheel part 52 ... X-axis slider (moving means)
57 ... Feeding mechanism (feeding means)
11 0 ... engineering tool detection device (detection means)
113 ... Cam rod
114 ... sensor 140 ... discriminating means

Claims (1)

Holding means having a flat holding surface for holding a wafer having a circular device forming region having a plurality of semiconductor devices formed on the front surface and an outer peripheral surplus region surrounding the device forming region in a state where the back surface is exposed. When,
In the wafer held on the holding surface by a tool that is arranged to face the holding surface and extends in a direction substantially orthogonal to the holding surface and is detachably attached to the rotating shaft. Processing means for processing only the back surface corresponding to the device formation region;
Feeding means for processing and feeding the processing means toward the wafer held on the holding surface;
A processing apparatus comprising a moving means for relatively moving the processing means in a direction parallel to the holding surface,
The tool is fixed to the end surface of the grindstone fixing portion, a cylindrical outer peripheral surface concentric with the rotating shaft, and a grindstone fixing portion facing the holding surface and having an end surface substantially parallel to the holding surface, An annular grindstone portion having an outer diameter substantially the same diameter as the cylindrical outer peripheral surface,
Furthermore, the cylindrical outer peripheral surface of the grindstone fixing portion comes into contact with the outer peripheral position of the grindstone fixing portion at an arbitrary position when the processing means is relatively moved in a direction parallel to the holding surface by the moving means. Detecting means for detecting
Determining means for determining the type of the tool based on the outer diameter position of the grindstone fixing portion detected by the detecting means ;
The detection means is disposed horizontally on the movement path of the processing means by the relative movement, and rotates when the cylindrical outer peripheral surface of the grindstone part contacts, and a sensor that detects the rotated cam rod. And comprising
The discriminating means is discriminated according to a moving distance of the machining means from a reference point set in the middle of the moving path of the machining means until the sensor detects the cam rod. A processing apparatus characterized by discriminating the type of the tool based on the above .

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