JP2013035097A - Contact detection method of moving object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a contact detection method of a moving object, capable of bringing two objects as close as possible to each other while maintaining a gap between the two objects when bringing the two objects close to each other, and capable of detecting the fact that the two objects have approached to each other.SOLUTION: The contact detection method of a moving object detects whether the two objects, at least one of which moves as a moving object, approach to each other by a predetermined distance. The contact detection method uses a contact sensor that includes: a flexible base part preferably located at least between the two objects and thicker than the predetermined distance; and a flexible light reflection part formed in at least a partial surface layer part of the base part.

Description

  The present invention relates to a moving body contact detection method for detecting whether or not two objects moving at least one of them as a moving body have approached a predetermined distance.

  In the manufacture of conventional semiconductor devices, for example, after manufacturing a wafer made of silicon with a predetermined thickness, after forming a semiconductor device on the surface of the wafer and grinding the back side of the wafer to a predetermined thickness A series of steps of dividing into each semiconductor device is known.

  Among the series of steps, in the step of grinding the back side of the wafer, it is known that grinding or polishing with a grindstone is performed by a grinding device called a grinder (see, for example, Patent Document 1). The grinding apparatus includes a chuck table that rotates while holding a wafer, and a spindle that rotates a wheel mount with a grinding wheel mounted on the lower surface at a high speed. The grinding wheel that rotates at a high speed is lowered to lower the annular base of the grinding wheel. Processing is performed in which the wafer is gradually thinned with a grindstone disposed under the table.

JP 2006-075929 A

  With the recent increase in diameter of wafers, the grinding wheel is also increased in diameter, and it is necessary to consider the workability when mounting the increased grinding wheel on the wheel mount. Specifically, the grinding wheel is mounted on the wheel mount by gradually lowering the spindle equipped with the wheel mount, reducing the distance between the grinding wheel and the wheel mount, and then lifting the grinding wheel. This is done by attaching it to the lower surface of the mount. Since the grinding wheel having a larger diameter becomes heavier, the burden of lifting the grinding wheel becomes more and more heavy.

  Here, if the distance between the grinding wheel and the wheel mount can be shortened as much as possible, the burden of lifting the grinding wheel is reduced, and the work can be facilitated. However, since the distance between the grinding wheel and the wheel mount has been confirmed by visual inspection in the past, there is a margin in the distance between the grinding wheel and the wheel mount because of concern about the collision between the two and the occurrence of damage due to the collision. Therefore, it has been difficult to facilitate the work.

  On the other hand, it is considered that there are many situations where it is preferable to make the distances as close as possible in the operation of assembling the parts of the apparatus, not limited to the above-described grinding apparatus. Moreover, not only in the situation where such an apparatus is assembled, but in a situation where two objects are brought close together, when one becomes a moving body and approaches the other stationary body, or when both move and approach each other, It is considered that there is a need to bring the two as close as possible while maintaining the gap between them, and to detect that the two have approached each other.

  Therefore, the present invention provides a method for detecting contact of a moving body, in which, when two objects are brought close to each other, both can be brought as close as possible while maintaining a gap between the two objects, and it is possible to detect that both have come close to each other. The purpose is to provide.

  According to the first aspect of the present invention, there is provided a moving body contact detection method for detecting whether two objects, at least one of which is moving as a moving body, have approached a predetermined distance, wherein at least two objects Using a contact sensor having a flexible base part thicker than a predetermined distance to be provided between and a flexible light reflecting part formed on at least a part of the surface layer of the base part, A contact sensor is installed so that a part of the reflection part is sandwiched between two objects, and the light reflection part is bent together with the base part by moving the moving body to contact the light reflection part. Based on the change in color before and after the contact of the moving body at the bent part formed around the boundary between the part sandwiched between the two objects and the part not sandwiched in the part, the two objects are Close to distance Or to detect whether the absence, contact detection method for a mobile body, characterized in that there is provided.

  Preferably, light is emitted from the light source to the light reflecting portion.

  According to the present invention, when two objects are brought close to each other, it is possible to bring them close as much as possible while maintaining a gap between them, and to detect that both are approaching.

It is an external appearance perspective view of a grinding device. It is a perspective view which shows the positional relationship of the chuck table and grinding wheel at the time of grinding. It is a perspective view of a grinding wheel. It is sectional drawing of the grinding wheel fixed to the wheel mount. (A) is a perspective view of a contact sensor. (B) is a side view of a contact sensor. (A) is a side view which shows about the state which installed the contact sensor between the wheel mount and the grinding wheel. (B) is a top view showing a state in which a contact sensor is installed between the wheel mount and the grinding wheel. (A) is a side view showing a state in which the wheel mount is brought close to the grinding wheel at a predetermined distance. (B) is a top view showing a state in which the color of the contact sensor has changed. (A) It is a side view shown about the condition which removes a contact sensor. (B) is a side view showing a state where a grinding wheel is mounted on a wheel mount.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an external perspective view of a grinding apparatus 2 which is an example of an apparatus assumed to implement the moving body contact detection method according to the present invention. The housing 4 of the grinding device 2 is composed of a horizontal housing part 6 and a vertical housing part 8.

  A pair of guide rails 12 and 14 extending in the vertical direction are fixed to the vertical housing portion 8. A grinding means (grinding unit) 16 is mounted along the pair of guide rails 12 and 14 so as to be movable in the vertical direction. The grinding unit 16 is attached to a moving base 18 that moves up and down along a pair of guide rails 12 and 14 via a support portion 20.

  The grinding unit 16 includes a spindle housing 22 attached to the support portion 20, a spindle 24 rotatably accommodated in the spindle housing 22, and a servo voter 26 that rotationally drives the spindle 24.

  The grinding apparatus 2 includes a grinding unit feed mechanism 44 that moves the grinding unit 16 in the vertical direction along the pair of guide rails 12 and 14. The grinding unit feed mechanism 44 includes a ball screw 46 and a pulse motor 48 fixed to one end of the ball screw 46. When the pulse motor 48 is pulse-driven, the ball screw 46 rotates, and the moving base 18 is moved in the vertical direction via the nut of the ball screw 46 fixed inside the moving base 18.

  A chuck table 50 sucks and holds the wafer 11 to be ground, and is configured to be movable in the Y-axis direction by a chuck table moving mechanism (not shown). That is, the chuck table 50 is moved in the Y-axis direction between the illustrated wafer loading / unloading positions and the grinding position facing the grinding wheel 30. 52 and 54 are bellows.

  As shown in FIG. 2, a wheel mount 28 is fixed to the tip of the spindle 24, and a grinding wheel 30 is attached to the wheel mount 28 with a screw 31. The grinding wheel 30 is configured by fixing a plurality of grinding wheels 34 in which diamond abrasive grains having a particle diameter of 0.3 to 1.0 μm are hardened by vitrified bond or the like to the free end portion on the lower side of the annular base 32. .

  As shown in FIG. 3, the grinding wheel 30 is configured to have an annular base 32. Screw holes 33 for attaching the annular base 32 to the wheel mount 28 are formed at a plurality of locations on the annular base 32 in the vertical direction. As shown in FIG. 4, each screw hole 33 is provided at a position corresponding to a through hole 29 formed in the wheel mount 28 in the vertical direction, and the screw 31 is inserted into the screw hole 33 through the through hole 29. By screwing, the grinding wheel 30 is attached to the lower part of the wheel mount 28 as shown in FIG.

  In this embodiment, in order to facilitate the mounting operation of the grinding wheel 30 to the wheel mount 28, the wheel mount 28 is brought close to a predetermined distance with respect to the grinding wheel 30. The contact sensor 60 shown is used. The contact sensor 60 includes a base portion 61 and a light reflecting portion 62 formed on at least a part of the surface layer portion of the base portion 61.

  The base portion 61 can be composed of an elastic body such as rubber or sponge, and is composed of a plate-shaped member in this embodiment. Note that the base portion 61 is not limited to a flat plate shape, and may be configured in a rod shape or a sheet shape.

  In the present embodiment, the thickness dimension M of the base portion 61 is set to be larger than at least a predetermined distance H (see FIG. 7A) secured between the wheel mount 28 and the grinding wheel 30. In addition, the total thickness of the base portion 61 and the light reflecting portion 62 may be set larger than a predetermined distance H (see FIG. 7A). The “predetermined distance H” here is a distance finally set between the wheel mount 28 and the grinding wheel 30. In other words, “the case where the wheel mount 28 and the grinding wheel 30 are brought as close as possible”. Distance ".

  The light reflecting portion 62 can be configured from a flexible and light reflecting member such as a resin film that reflects light or an aluminum foil. In this embodiment, one side of the base portion 61 is provided. It is comprised by the sheet-like member stuck on the surface. As will be described later, the light reflecting section 62 is configured to detect contact with the detected object by deforming a part thereof. When an object comes into contact with the light reflecting portion 62, the incident angle of light with respect to the surface of the light reflecting portion 62 serving as an interface changes (it may be interpreted that the reflection angle changes) and is visually recognized by the operator. The color will change. This color change becomes detection information, and the operator detects that the wheel mount 28 contacts the light reflecting portion 62.

  In the present embodiment, the base portion 61 and the light reflecting portion 62 are configured by a combination of different members, but in addition to this, a detection portion is provided on the surface layer portion of the base portion 61 by coating the base portion 61. The contact sensor 60 may be formed by forming the light reflecting portion 62 with a thick member, and the light reflecting portion 62 alone. Further, a configuration in which both the front and back surfaces of the base portion 61 and all the surface layer portions are covered with the sheet-like light reflecting portion 62 is also conceivable.

  Hereinafter, an example in which the grinding wheel 30 is mounted on the wheel mount 28 using the contact sensor 60 configured as described above will be described.

  As shown in FIG. 6A, the jig 35 is placed on the chuck table 50, and the grinding wheel 30 is placed on the jig 35 with the grinding wheel 34 facing down. Although the specific configuration of the jig 35 is not particularly limited, the upper and lower positions of the grinding wheel 30 can be easily fixed without lifting the grinding wheel 30 in the subsequent fixing work to the wheel mount 28. It is preferable to make it possible to change the above.

  Next, the chuck table 50 is moved in the Y-axis direction so that the grinding wheel 30 is positioned below the wheel mount 28. At this time, the movable base 18 (see FIG. 1) is raised so that the wheel mount 28 is located sufficiently away from the chuck table 50.

  Next, as shown in FIGS. 6A and 6B, the contact sensor 60 is placed on the upper surface 32 a of the annular base 32 of the grinding wheel 30. Here, the contact sensor 60 is disposed at a position where a part of the light reflecting portion 62 is sandwiched between the grinding wheel 30 and the wheel mount 28. Thereby, the boundary part 63 of the site | part 63a pinched | interposed in the light reflection part 62 and the site | part 63b not pinched is comprised. The contact sensor 60 may be bonded to the upper surface 32a of the grinding wheel 30 in advance before moving the chuck table 50 in the Y-axis direction.

  In the present embodiment, the base portion 61 of the contact sensor 60 is placed on the upper surface 32a of the grinding wheel 30, and the light reflecting portion 62 is disposed so as to face the lower surface 28b of the wheel mount 28, whereby the light reflecting portion 62. Is visible from above.

  A light source 64 that can illuminate the light reflecting portion 62 is preferably provided at a position above the contact sensor 60 in order to make it easier to visually recognize the color change of the light reflecting portion 62 at the time of contact detection. As used herein, “color change” refers to a change in at least one of the three attributes of color (hue, lightness, and saturation) that can be identified by the operator's vision. It is.

  Next, as shown in FIG. 7A, the lower surface 28b of the wheel mount 28 is gradually lowered so as to approach the contact sensor 60, and when a part of the light reflecting portion 62 is pushed downward by the lower surface 28b, the grinding wheel Around the boundary 63 between the part 63a sandwiched between the wheel mount 28 and the wheel mount 28 and the part 63b that is not sandwiched, a bent part 62a formed by the deformation of the light reflecting part 62 is formed.

  Before and after the bending portion 62a is formed, a change occurs in the incident angle of light at the boundary portion 63, so that a visible color changes. The operator can detect that the lower surface 28b of the wheel mount 28 has contacted the contact sensor 60 by visually recognizing this color change.

  Based on this detection, the operator can grasp that the wheel mount 28 has approached the grinding wheel 30, that is, that the wheel mount 28 has reached a position at a predetermined distance H from the grinding wheel 30.

  Next, the lowering of the wheel mount 28 is stopped, and the contact sensor 60 sandwiched between the wheel mount 28 and the grinding wheel 30 is removed. Since the contact sensor 60 is formed of an elastic body, the contact sensor 60 can be easily removed.

  Next, as shown in FIG. 8B, the jig 35 is adjusted so as to move the grinding wheel 30 upward, the upper surface 32a of the annular base 32 is brought into contact with the lower surface 28b of the wheel mount 28, and the wheel The screw 31 is inserted into the through hole 29 of the mount 28 from above and screwed into the screw hole 33 of the grinding wheel 30, so that the grinding wheel 30 is attached to the wheel mount 28.

  As described above, in the present embodiment, the semiconductor wafer grinding apparatus has been described as an example. However, the present invention can be used in many forms. For example, in the present embodiment, the relationship between the two objects of the wheel mount 28 and the grinding wheel 30 is such that only one wheel mount 28 moves. However, for example, the two objects move to approach each other. Even in this case, the present invention can be applied.

  Thus, according to the present invention, it is possible to provide a moving body contact detection method for detecting whether two objects moving at least one as a moving body have approached a predetermined distance. As a specific method, a flexible base portion 61 that is thicker than a predetermined distance to be provided between at least two objects, and a flexibility formed on at least a part of the surface layer portion of the base portion 61. A contact sensor 60 having a light reflecting portion 62 and a contact sensor installed so that a part of the light reflecting portion 62 is sandwiched between two objects, and light from the light source 64 to the light reflecting portion. , The moving body is moved and brought into contact with the light reflecting portion 62, so that the light reflecting portion 62 is bent together with the base portion 61, and the light reflecting portion 62 is sandwiched between a portion 63 a sandwiched between two objects. Based on the color change before and after the contact of the moving body at the bent portion 62a formed around the boundary 63 of the non-existing portion 63b, it is detected whether the two objects are close to a predetermined distance. .

  According to the present invention as described above, when two objects are brought close to each other regardless of the type of the object, a method for bringing both objects as close as possible while maintaining a gap between the two objects and detecting that both objects are approaching each other. Can be used widely. In particular, according to the configuration of the present embodiment, the present invention can be implemented with many advantageous points such as an installation location is not limited, a power source is not required, and the configuration can be made at low cost.

  Furthermore, with the configuration of this embodiment, it is possible to set the predetermined distance H shown in FIG. 7A by setting the thickness dimension M of the base portion 61 shown in FIG. 5B. It becomes. That is, for example, when the thickness dimension M of the base portion 61 is 31 mm, the predetermined distance H can be realized to about 30 mm, and a plurality of contact sensors having different thickness dimensions M are prepared. According to this, it is possible to appropriately cope with a situation in which the required predetermined distance H is different.

22 Spindle housing 24 Spindle 28 Wheel mount 30 Grinding wheel 32 Annular base 34 Grinding wheel 35 Jig 60 Contact sensor 61 Base part 62 Light reflecting part 62a Deflection part 63 Boundary part 64 Light source

Claims (2)

A method for detecting contact of a moving body for detecting whether at least one of two objects moving as a moving body has approached a predetermined distance,
A flexible base portion thicker than a predetermined distance to be provided between at least the two objects;
A flexible light reflecting portion formed on at least a portion of the surface portion of the base portion;
Using a contact sensor with
Installing the contact sensor such that a part of the light reflecting portion is sandwiched between the two objects;
By moving the movable body and bringing it into contact with the light reflecting portion, the light reflecting portion is bent together with the base portion,
Based on the change in color before and after contact of the moving body at the bent portion formed around the boundary between the portion sandwiched between the two objects and the portion not sandwiched in the light reflecting portion,
A method for detecting contact of a moving body, comprising detecting whether or not the two objects are close to a predetermined distance. Irradiating the light reflecting portion with light from a light source;
The contact detection method of the moving body according to claim 1.

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