TW202044481A - Holding device capable of preventing a work piece from damage - Google Patents

Abstract

The object of the present invention is to provide a holding device capable of preventing a work piece from damage. To achieve the object, the holding device is provided to hold a work piece, and the holding device is characterized in including: a holding means for holding the work piece by a holding surface, and sucking the outer circumferential region of the work piece on an annular suction region formed in a region covered by the work piece held by the holding surface; a pressure measurement means for measuring the pressure of a suction path connected to the suction region; and a control means for determining that there is no foreign matter existed between the work piece and the holding surface when the pressure measured by the pressure measurement means is lower than the predetermined threshold value, and determining that there is a foreign matter existed between the work piece and the holding surface if the pressure measured by the pressure measurement means is higher than the threshold value.

Description

Holding device

The present invention relates to a holding device for holding a workpiece.

Dividing a semiconductor wafer on which elements such as IC (Integrated Circuit) and LSI (Large Scale Integration) are formed is divided, thereby manufacturing a plurality of element wafers each equipped with elements. In addition, a packaged component is manufactured by dividing the packaged substrate. The packaged substrate is coated with a sealing material (compression mold resin) made of resin with a plurality of component chips mounted on the substrate Way formed. The packaged components are built in various electronic devices such as mobile phones or personal computers.

In recent years, along with the miniaturization and thinning of electronic equipment, the thinning of device chips or packaged components has also been required. Therefore, a method of grinding and thinning the semiconductor wafer or package substrate before division is used.

Dividing the workpiece represented by the above-mentioned semiconductor wafer or package substrate is a cutting device that uses, for example, a ring-shaped dicing knife to cut the workpiece. In addition, to reduce the thickness of the workpiece, for example, a grinding device that grinds the workpiece with a grinding stone is used.

A processing device such as a cutting device or a grinding device is provided with a holding platform that holds the workpiece. For example, Patent Document 1 discloses a holding platform provided with a porous plate made of a porous member such as porous ceramic. The upper surface of the perforated plate constitutes a holding surface for holding the workpiece, and the holding surface is connected to the suction source. In the state where the workpiece is arranged on the holding surface of the porous plate, the negative pressure of the suction source is applied to the holding surface, whereby the workpiece is sucked and held on the holding platform. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2004-14939 A

[Problem to be solved by the present invention]

When the workpiece is held by the holding platform, the workpiece or the perforated plate of the holding platform may be attached with foreign matter such as chips (processing chips) generated by the processing of the workpiece. In addition, when the object to be processed is placed on the holding platform with the foreign object attached, the foreign object may penetrate between the object to be processed and the holding platform.

In a state where a foreign object is present between the object to be processed and the holding platform, when the object to be processed is sucked and held by the holding platform, the area where the object is in contact with the foreign object is deformed. As a result, local stress may be applied to the workpiece and the workpiece may be damaged.

The present invention is a researcher in view of this problem, and its object is to provide a holding device that can prevent damage to the workpiece. [Means to solve the problem]

According to one aspect of the present invention, there is provided a holding device that holds a processed object. The holding device is characterized by including a holding means for holding the processed object on a holding surface and is formed by The ring-shaped suction area of the area covered by the workpiece of the holding surface attracts the outer peripheral area of the workpiece; pressure measuring means for measuring the pressure of the suction path connected to the suction area; and control means, When the pressure measured by the pressure measuring means is lower than the preset threshold value, it is judged that there is no foreign matter between the workpiece and the holding surface, and the pressure measured by the pressure measuring means If the pressure is higher than the threshold, it is determined that there is a foreign object between the workpiece and the holding surface. [Effects of Invention]

A holding device according to one aspect of the present invention is provided with a holding means: in the ring-shaped suction area, suck the outer peripheral area of the workpiece. When this holding means is used, if a foreign object is present between the workpiece and the holding means, the workpiece is not attracted and held by the holding means. Thereby, it is possible to prevent the area where the workpiece is in contact with the foreign body from deforming locally and causing damage to the workpiece.

In addition, the holding device of one aspect of the present invention is provided with: pressure measuring means for measuring the pressure of the suction path connected to the suction area; and control means for determining based on the pressure measured by the pressure measuring means The presence or absence of foreign bodies. With this, when the object to be processed is placed on the holding means, it is possible to confirm whether or not a foreign object exists between the object to be processed and the holding means.

Hereinafter, referring to the attached drawings, embodiments of the present invention will be described. First, a configuration example of the holding device (holding mechanism) of this embodiment will be described. FIG. 1(A) is a perspective view showing the holding device (holding mechanism) 2.

The holding device 2 is provided with a holding platform (holding means) 4 to hold the workpiece 11. The holding platform 4 is made of a non-porous material (non-porous metal, glass, ceramic, etc.), and is formed in a circular shape in a plan view. On the upper surface of the holding platform 4, a holding surface 4a for holding the workpiece 11 is formed.

The to-be-processed object 11 is a member (a to-be-held object or a to-be-processed object) that is subjected to processing, washing, etc., in a state held by the holding platform 4. For example, the workpiece 11 is a disk-shaped wafer made of silicon or the like, and has a front surface 11a and a back surface 11b. The to-be-processed object 11 is divided into a plurality of regions by planned dividing lines (cutting lanes) 13 arranged in a grid to cross each other. On the surface 11a side of the regions, IC (Integrated Circuit), LSI (Large Scale Integration), LED (Light Emitting Diode) and other components 15 constituted.

In addition, the material, shape, structure, size, etc. of the workpiece 11 are not limited. For example, the workpiece 11 may be a wafer of any shape and size composed of materials other than silicon (GaAs, InP, GaN, SiC, etc.), sapphire, glass, ceramic, resin, metal, etc. In addition, there are no restrictions on the type, number, shape, structure, size, arrangement, etc. of the elements 15.

The holding surface 4a of the holding platform 4 is formed into a shape and size that can support the entire workpiece 11. Specifically, the holding surface 4a is formed in a circular shape with a larger diameter than the workpiece 11. For example, when the diameter of the workpiece 11 is about 300 mm, the diameter of the holding surface 4a can be set to about 310 mm. Furthermore, the workpiece 11 is arranged on the holding platform 4 so that its center position coincides with the center position of the holding platform 4. However, the shape and size of the holding surface 4a can be appropriately changed according to the shape and size of the workpiece 11.

On the holding surface 4a side of the holding platform 4, an annular recess (suction area) 4b is formed along the outer periphery of the holding platform 4. The recess 4b is formed in an area covered by the workpiece 11 when the workpiece 11 is arranged on the holding platform 4. Specifically, the recessed portion 4b is formed into an annular shape having a smaller diameter than the workpiece 11. For example, the concave portion 4b is formed with a predetermined width (for example, about 1 to 2 mm) at a position away from the outer periphery of the holding platform 4 to the center of the holding platform 4 by about 3 to 6 mm.

In addition, although FIG. 1(A) shows an example in which the recessed portion 4b is formed in a continuous line shape, the shape of the recessed portion 4b is not limited. For example, a plurality of linear recesses 4b may be arranged in a ring shape along the outer periphery of the holding platform 4. That is, the linear recessed portion 4b may be formed in a discontinuous linear shape (dotted line shape) along the outer periphery of the holding platform 4. In addition, in the holding platform 4, two or more annular recesses 4b having different diameters may be formed concentrically.

In addition, the holding platform 4 is connected to a rotation drive source (not shown) such as a motor, which rotates the holding platform 4 about a rotation axis approximately parallel to the Z-axis direction (vertical direction, vertical direction). In addition, the holding platform 4 is connected to a moving mechanism (not shown) that moves the holding platform 4 in the X-axis direction (first horizontal direction) or the Y-axis direction (second horizontal direction).

When the workpiece 11 is arranged on the holding surface 4a of the holding platform 4, a part of the area on the outer peripheral edge side of the workpiece 11 (outer peripheral area) overlaps the recessed portion 4b. In this state, when the negative pressure of the suction source 10 (see FIG. 2) is applied to the concave portion 4b, the area (outer peripheral area) overlapping with the concave portion 4b of the workpiece 11 is sucked, and the workpiece 11 is held by the platform 4 Attract and maintain. That is, the recessed portion 4b corresponds to a suction area that sucks the outer peripheral area of the workpiece 11.

FIG. 1(B) is a perspective view showing the holding device 2 in a state where the workpiece 11 is held. The workpiece 11 held by the holding device 2 is subjected to various treatments such as processing and washing.

FIG. 2 is a cross-sectional view showing the holding device 2 in a state where the workpiece 11 is held. The recess 4b formed in the holding platform 4 is connected to a suction path 6 formed inside the holding platform 4, and the suction path 6 is connected to a suction source 10 such as an ejector via a valve 8. In addition, the suction path 6 is connected to a fluid supply source 14 via a valve 12, and the fluid supply source 14 supplies fluid such as air to the suction path 6. Furthermore, a pressure measuring device (pressure measuring means) 16 is connected to the suction path 6, and the pressure measuring device measures the pressure of the suction path 6.

In addition, the holding device 2 is provided with a control unit (control means) 30, which is connected to each component (valve 8, suction source 10, valve 12, fluid supply source 14, pressure measuring device 16, etc.) constituting the holding device 2. Rotation drive source, moving mechanism, etc.). The control unit 30 is composed of a computer or the like, and controls the operation of each component of the holding device 2.

When holding the workpiece 11 by the holding device 2, first, the workpiece 11 is placed on the holding surface 4 a of the holding platform 4. For example, the workpiece 11 is arranged on the holding platform 4 so that the surface 11 a side is exposed upward and the back surface 11 b side faces the holding surface 4 a of the holding platform 4. At this time, the entire recess 4b formed in the holding platform 4 is covered by the workpiece 11, and the outer peripheral area of the workpiece 11 overlaps the recess 4b.

Then, in a state where the workpiece 11 is arranged on the holding platform 4, the valve 8 is opened and the valve 12 is closed. As a result, the negative pressure of the suction source 10 acts on the back surface 11b side of the workpiece 11 via the suction path 6 and the recess 4b, and the outer peripheral area of the workpiece 11 is sucked. Thereby, the workpiece 11 is held by the holding platform 4.

On the other hand, when removing the workpiece 11 from the holding device 2, the valve 8 is closed and the valve 12 is opened. By this, the suction of the workpiece 11 by the suction source 10 is released. In addition, fluid (air or the like) is supplied to the suction path 6 from the fluid supply source 14. This fluid is supplied from the suction path 6 to the recessed portion 4b, and is ejected upward from the recessed portion 4b.

In this way, when the workpiece 11 is removed, when fluid is supplied to the suction path 6, the vacuum is released inside the suction path 6 and the recess 4b, and the fluid is blown to the back of the workpiece 11 11b side. Thereby, the removal of the processed object 11 can be assisted, and the processed object 11 can be easily removed from the holding platform 4.

In addition, as long as the removal of the workpiece 11 can be assisted, the composition of the fluid supplied from the fluid supply source 14 is not limited. For example, as the fluid, water or a mixed fluid mixed with water or air may also be used. In addition, the structure of the fluid supply source 14 can be appropriately changed according to the composition of the fluid.

For example, a processing device for processing the workpiece 11 or a washing device for washing the workpiece 11 is provided with the holding device 2 described above. Examples of processing devices include a cutting device that cuts the workpiece 11 with a ring-shaped cutter, a grinding device that grinds the workpiece 11 with a grinding stone, and a grinding pad to grind the workpiece. The polishing device of 11 and the laser processing device for processing the workpiece 11 by irradiation of laser light, etc. In addition, the control unit 30 of the holding device 2 may be integrated with the control unit provided in the aforementioned processing device or washing device.

When the workpiece 11 is held by the holding device 2, the workpiece 11 or the holding platform 4 may have foreign matter (swarf (processing chips) generated by the processing of the workpiece 11) attached to it. In addition, when the workpiece 11 is placed on the holding platform 4 in a state where the foreign matter is present, the foreign matter may penetrate between the workpiece 11 and the holding platform 4.

FIG. 3 is a cross-sectional view of the holding device 2 showing a state in which foreign matter 17 has penetrated between the workpiece 11 and the holding platform 4. When arranging the workpiece 11 on the holding platform 4, when the foreign object 17 is clamped by the holding platform 4 and the workpiece 11, the workpiece 11 becomes one end side (in FIG. 3, the right end side) A state where it is in contact with the holding platform 4 and the other end side (in FIG. 3, the left end side) is not in contact with the holding platform 4.

Here, consider the following situation: suppose that the holding surface 4a side of the holding platform 4 is constituted by a porous plate or the like made of a porous member, and the entire area overlapping with the workpiece 11 of the holding surface 4a functions as a suction area Features. In this case, when the negative pressure of the suction source 10 is applied to the holding surface 4a, first, the one end side of the to-be-processed object 11 in contact with the holding platform 4 is sucked to the holding surface 4a.

Moreover, by the suction force acting on the entire area overlapping with the workpiece 11 of the holding surface 4a, the workpiece 11 is smoothly attracted from one end side to the other end side. As a result, the foreign matter 17 is sandwiched between the holding surface 4a and the workpiece 11, and the workpiece 11 is held along the holding surface 4a in a state where only the area in contact with the foreign matter 17 is not in contact with the holding surface 4a. . As a result, the area where the workpiece 11 and the foreign object 17 are in contact is deformed, and local stress is applied to the area, and the workpiece 11 may be damaged.

On the other hand, in the holding device 2 of this embodiment, the ring-shaped suction area (recess 4b) formed by the holding platform 4 in the outer peripheral area of the workpiece 11 is sucked, and in the central area of the workpiece 11, It contains an area not attracted by the holding platform 4. Thereby, compared with the case where the whole of the processed object 11 is attracted, the attraction force acting on the processed object 11 is moderately weakened.

Therefore, when the foreign matter 17 is present between the workpiece 11 and the holding platform 4, even if the negative pressure of the suction source 10 is applied to the recess 4b, the back surface 11b side of the workpiece 11 will not be in close contact with the holding surface 4a, and the workpiece 11 will not be attracted and held. That is, the state shown in FIG. 3 is maintained. Thereby, in a state where the workpiece 11 is in contact with the foreign matter 17, the workpiece 11 can be prevented from being damaged by being held along the holding surface 4a.

In addition, when "the workpiece 11 is processed or cleaned in a state where the foreign matter 17 is present and the workpiece 11 is not properly held by the holding platform 4 (see FIG. 3)," the workpiece 11 may be processed or washed. The workpiece 11 may be damaged due to the drop of the workpiece 11 and the like. Therefore, when arranging the workpiece 11 on the holding platform 4, it is better to confirm whether there is a foreign object 17 between the workpiece 11 and the holding platform 4. Therefore, the holding device 2 uses the pressure measuring device 16 and the control unit 30 to determine the presence or absence of the foreign matter 17.

Specifically, first, while measuring the pressure of the suction path 6 with the pressure measuring device 16, the workpiece 11 is arranged on the holding platform 4. Here, when the foreign matter 17 does not exist between the workpiece 11 and the holding platform 4, the entire back surface 11b side of the workpiece 11 will be in contact with the holding surface 4a, so that the holding platform 4 can properly hold To be processed 11 (see Figure 2). Furthermore, the pressure P1 of the suction path 6 at this time is measured by the pressure measuring device 16.

On the other hand, when the foreign matter 17 exists between the workpiece 11 and the holding platform 4, the workpiece 11 is not held by the holding platform 4, and one end side of the workpiece 11 is maintained relative to the holding platform 4. The state where the other end side is not connected to the holding platform 4 (see FIG. 3). Furthermore, the pressure P2 of the suction path 6 at this time is measured by the pressure measuring device 16.

Here, when the entire back surface 11b side of the workpiece 11 is not in contact with the holding surface 4a (see FIG. 3), the negative pressure of the suction source 10 will leak from the recessed portion 4b not covered by the workpiece 11 . Therefore, the pressure P2 of the suction path 6 is difficult to decrease, and the pressure P2 is higher than the pressure P1 of the state where the entire concave portion 4b is not covered by the workpiece 11 (see FIG. 2). That is, the pressure of the suction path 6 differs depending on whether there is a foreign object 17. Therefore, the control unit 30 determines the presence or absence of the foreign matter 17 based on the value of the pressure of the suction path 6.

Specifically, the control unit 30 includes a determination unit 32 that determines the presence or absence of the foreign object 17 based on the pressure of the suction path 6 and a storage unit 34 that stores various data used in the processing performed by the determination unit 32. The pressure of the suction path 6 measured by the pressure measuring device 16 is input to the determination unit 32. In addition, the memory unit 34 stores a threshold value Pth corresponding to the boundary between the pressure P1 of the suction path 6 when the foreign matter 17 is absent and the pressure P2 of the suction path 6 when the foreign matter 17 is present. In addition, the threshold value Pth is a value that satisfies P1<Pth<P2, and is obtained based on experiments in advance, for example.

The determination unit 32 compares the pressure P of the suction path 6 measured by the pressure measuring device 16 with the threshold value Pth memorized in the memory unit 34. Moreover, when the pressure P is lower than the threshold value Pth, it is determined that there is no foreign matter 17 between the workpiece 11 and the holding surface 4a. On the other hand, when the pressure P is higher than the threshold value Pth, it is determined that there is a foreign matter between the workpiece 11 and the holding surface 4a.

The result of the determination performed by the determination unit 32 is, for example, displayed on a display unit (not shown) included in the holding device 2. Or, the determination result is output from the control unit 30 to the outside of the holding device 2. Moreover, when it is determined that the foreign matter 17 is present, the workpiece 11 and the holding platform 4 are cleaned, and the foreign matter 17 is removed, for example.

As described above, the holding device 2 of the present embodiment is provided with the holding platform 4 and sucks the outer peripheral area of the workpiece 11 with the annular recess 4b. When the holding platform 4 is used, if the foreign matter 17 is present between the workpiece 11 and the holding platform 4, the workpiece 11 is not sucked and held by the holding platform 4. Thereby, it is possible to prevent the area where the workpiece 11 is in contact with the foreign body 17 from being deformed locally and causing damage to the workpiece 11.

In addition, the holding device 2 is provided with: a pressure measuring device 16 that measures the pressure of the suction path 6 connected to the concave portion 4b; and a control unit 30 that judges foreign matter 17 based on the pressure measured by the pressure measuring device 16 The presence or absence. Thereby, when the workpiece 11 is placed on the holding platform 4, it is possible to confirm whether the foreign matter 17 exists between the workpiece 11 and the holding platform 4.

In addition, in this embodiment, although an example in which the annular recessed portion 4b is formed in the holding platform 4 is shown, the structure of the holding platform 4 can be appropriately changed within the range in which the workpiece 11 can be held. For example, one or more recesses opened to the holding surface 4a may be further formed inside the recess 4b (inward in the radial direction of the holding platform 4 than the recess 4b).

More specifically, a cylindrical recess having a predetermined diameter (for example, about 1 to 6 mm) may be formed in the center of the holding platform 4. The cylindrical recess is connected to the suction path 6 and functions as a suction port when the workpiece 11 is held by the holding platform 4 and as a discharge port for fluid ejection when the workpiece 11 is removed from the holding platform 4 . By providing the cylindrical recess, the workpiece 11 can be held by the holding platform 4 more reliably, and the workpiece 11 can be removed more easily.

In addition, the structure, method, etc. of the above-mentioned embodiment can be appropriately changed and implemented without departing from the scope of the object of the present invention.

11: processed objects 11a: surface 11b: back 13: Splitting the planned line (cutting path) 15: Components 17: foreign body 2: Holding device (holding mechanism) 4: Keep the platform (main means) 4a: Keep the face 4b: Concavity (attraction area) 6: suction path 8: Valve 10: Attraction source 12: Valve 14: fluid supply source 16: Pressure measuring device (pressure measuring means) 30: Control section (control means) 32: Judgment Department 34: Memory Department

[Fig. 1] Fig. 1(A) is a perspective view showing the holding device; Fig. 1(B) is a perspective view showing the holding device in a state where the workpiece is held. [Fig. 2] A cross-sectional view showing the holding device in the state of holding the workpiece. [Fig. 3] A cross-sectional view of the holding device showing a state where foreign matter has penetrated between the workpiece and the holding platform.

2: holding device

4: keep the platform

4a: Keep the face

4b: recess

11: processed objects

11a: surface

11b: back

13: Splitting the planned line

15: Components

Claims (1)

A holding device is used to hold a processed object. The holding device is characterized by: A holding means for holding the processed object with a holding surface, and attracting the outer peripheral area of the processed object in a ring-shaped suction area formed in the area covered by the processed object by the holding surface; The pressure measuring means measures the pressure of the suction path connected to the suction area; and The control means determines that there is no foreign matter between the workpiece and the holding surface when the pressure measured by the pressure measurement means is lower than the preset threshold value, and the pressure measurement means When the measured pressure is higher than the threshold value, it is determined that there is a foreign object between the workpiece and the holding surface.

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