JP2014143322A - Cleaning device and cleaning method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning device and a cleaning method capable of effectively cleaning, for example, such cleaning regions as a cut groove with a width of hundreds of μm to tens of μm serving as a specific cleaning region.SOLUTION: There is provided a cleaning device for cleaning a workpiece, comprising: holding means for holding a workpiece; cleaning liquid jetting means including a cleaning liquid jetting nozzle which jets a cleaning liquid to the workpiece held by the holding means; X direction moving means for relatively moving the cleaning liquid jetting means and the holding means in an X direction; Y direction moving means for relatively moving the cleaning liquid jetting means and the holding means in a Y direction orthogonal to the X direction; and imaging means for imaging the workpiece held by the holding means to detect a cleaning region.

Description

  The present invention relates to a cleaning apparatus and a cleaning method for cleaning a workpiece.

  Conventionally, for example, as disclosed in Patent Document 1, it is known that spin cleaning using a spinner cleaning device is performed after a workpiece such as a semiconductor wafer is cut.

  This spin cleaning is performed for the purpose of removing the cutting waste generated by the cutting process, and it is required that the cutting waste does not remain on the surface of the semiconductor wafer or the like in the cutting groove after the spin cleaning. Is.

JP 2006-128359 A

  However, in the cleaning mode by spin cleaning, it is expected that the cutting waste on the surface of the semiconductor wafer is washed away, but there is a concern that the cutting waste remains in the cutting groove.

  In particular, for example, when the width of the cutting groove serving as the cleaning region is as narrow as several hundred μm to several tens μm, the cleaning liquid cannot sufficiently reach the cutting groove. There is a concern that cutting waste remains.

  Since the cleaning is not performed after the spin cleaning after the chip division, the cutting waste that has not been removed by the spin cleaning remains as it is. And when cutting waste remains in a chip side surface (cutting groove), specifically, for example, there is a concern that the following problems may occur.

  The cutting waste adhering to the side surface of the chip picked up at the time of chip pick-up falls on the chip not picked up and adheres to the bonding pad. And when the cutting waste adheres on the bonding pad in this way, there is a problem that a bonding defect occurs in the subsequent bonding process.

  Also, the chip pick-up device and the inside of the handling device may be contaminated when chip waste in the cutting groove (chip side surface) is generated from the cutting groove (dropping off) during chip pick-up or handling. It is.

  Therefore, in view of the above problems, the present invention can effectively clean such a cleaning region even when, for example, a cutting groove having a width of several hundred μm to several tens of μm becomes a specific cleaning region. A cleaning apparatus and a cleaning method are provided.

  In the present invention, a cleaning apparatus for cleaning a workpiece, a holding means for holding the workpiece, and a cleaning liquid jetting means having a cleaning liquid jet nozzle for jetting cleaning liquid to the workpiece held by the holding means; The X direction moving means for relatively moving the cleaning liquid ejecting means and the holding means in the X direction, the Y direction moving means for relatively moving the cleaning liquid ejecting means and the holding means in the Y direction orthogonal to the X direction, and the holding means There is provided a cleaning device including an image pickup unit that picks up an image of the processed workpiece and detects a cleaning region.

  Preferably, the cleaning apparatus according to claim 1, wherein abrasive particles are mixed in the cleaning liquid.

  Preferably, there is also provided a cleaning method for cleaning a cleaning region of a workpiece having a cleaning region and a non-cleaning region, the holding step for holding the workpiece by the holding means, and the workpiece held by the holding means A cleaning region detecting step for picking up an image of an object by an imaging means and detecting a cleaning region; a cleaning liquid ejection nozzle is positioned in the cleaning region detected in the cleaning region detection step; And a cleaning step of cleaning the cleaning area of the workpiece by moving the holding means relative to each other.

  Preferably, the cleaning area has a plurality of intersecting line-shaped cleaning areas. In the cleaning step, the cleaning liquid is relatively moved in the X direction while the cleaning liquid is ejected from the cleaning liquid ejection nozzle to the workpiece, and in the X direction. 4. The cleaning method according to claim 3, wherein the indexing feed for positioning the cleaning liquid ejection nozzle in each line-shaped cleaning region by repeating relative movement in the orthogonal Y direction is repeated.

  Preferably, the cleaning method according to claim 3 or 4, wherein abrasive particles are mixed in the cleaning liquid.

  According to the present invention, a cleaning apparatus and a cleaning method capable of effectively cleaning a specific cleaning region are provided. Specifically, the image pickup means for detecting the cleaning region, the X-direction moving means and the Y-direction moving means for moving the cleaning liquid ejecting means and the holding means relative to each other in the X direction and the Y direction are provided. After detecting a specific cleaning area to be cleaned, the cleaning area can be effectively cleaned.

It is a perspective view of the washing | cleaning apparatus suitable for implementing this invention. It is a perspective view of the workpiece made into the object of washing. It is a figure explaining a holding step. It is a figure explaining a washing field detection step. It is a figure explaining a washing | cleaning step. It is a figure explaining washing removal of a layered product.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Referring to FIG. 1, there is shown a perspective view of a cleaning apparatus 2 suitable for carrying out the present invention. The cleaning device 2 includes a pair of guide rails 6 that are mounted on the stationary base 4 and extend in the X direction.

  The X-axis moving block 8 is moved in the X direction by an X-axis feed mechanism (X-axis feed means) 14 composed of a ball screw 10 and a pulse motor 12. A chuck table 20 is mounted on the X-axis moving block 8 via a cylindrical support member 22.

  The chuck table 20 has a suction holding unit 24 formed of porous ceramics or the like, and a holding surface 24 a is formed on the upper surface of the suction holding unit 24. A plurality of (four in this embodiment) clamps 26 for clamping the annular frame F shown in FIG. 2 are disposed on the chuck table 20.

  FIG. 2 shows a semiconductor wafer W that is an example of a workpiece to be cleaned. In the present embodiment, it is assumed that the cutting grooves M have already been processed for the division lines S1 and S2 of the wafer W. In FIG. 2, the plurality of division lines S1 and S2 are arranged in a lattice shape extending in the first direction and the second direction, respectively, and the device D is located in an area partitioned by the division lines S1 and S2. Is formed.

  In FIG. 2, a wafer W is attached to an adhesive tape T and is handled in a state of being fixed to an annular frame F via the adhesive tape T.

  The workpiece to be cleaned includes a workpiece such as an optical device wafer, a package substrate, glass, and ceramic in addition to the semiconductor wafer W as shown in FIG.

  The X-axis feed mechanism 14 shown in FIG. 1 is disposed on the lower surface of the scale 16 disposed on the stationary base 4 along the guide rail 6 and the X-axis moving block 8 that reads the X coordinate value of the scale 16. Read head 18. The read head 18 is connected to a control device (not shown) of the cleaning device 2.

  A pair of guide rails 28 extending in the Y direction are further fixed on the stationary base 4. The Y-axis moving block 30 is moved in the Y-axis direction by a Y-axis feed mechanism (index feed mechanism) 36 composed of a ball screw 32 and a pulse motor 34. The Y-axis feed mechanism is connected to a control device (not shown), and the position of the cleaning liquid ejection unit 46 in the Y-axis direction is controlled by the control of the pulse motor 34 by the control device.

  The Y-axis moving block 30 is formed with a pair of guide rails 38 (only one is shown) extending in the Z-axis direction. The Z-axis moving block 40 is moved in the Z-axis direction by a Z-axis feed mechanism 44 composed of a ball screw (not shown) and a pulse motor 42. The Z-axis feed mechanism is connected to a control device (not shown), and the position of the cleaning liquid ejection unit 46 in the Z-axis direction is controlled by the control of the pulse motor 42 by the control device.

  46 is a cleaning liquid ejection unit (cleaning liquid ejection unit means), and a housing 48 of the cleaning liquid ejection unit 46 is inserted into the Z-axis moving block 40 and supported. A cleaning liquid ejection nozzle 50 is provided at the front end of the housing 48, and the cleaning liquid is ejected from the cleaning liquid ejection nozzle 50 toward the cleaning region of the wafer W.

  A flow path 60 for supplying the cleaning liquid to the cleaning liquid ejection nozzle 50 is disposed in the housing 48. The flow path 60 is connected to a cleaning liquid supply source 66 and an abrasive grain supply source 68 via switching valves 62 and 64, and one of the cleaning liquid and the abrasive grains from the cleaning liquid ejection nozzle 50 is controlled by the switching valves 62 and 64. Alternatively, a mixture is ejected.

  An alignment unit (alignment means) 52 is mounted on the housing 48. The alignment unit 52 has an imaging unit (imaging means) 54 that images the wafer W held on the chuck table 20. The cleaning liquid ejection nozzle 50 and the imaging unit 54 are arranged in alignment in the X direction.

  In this imaging unit 54, the surface of the wafer W is imaged, and the position of the cutting groove M (see FIG. 2) formed in the wafer W is detected. In this embodiment, the position of the cutting groove M is defined as a cleaning region.

  As described above, as shown in FIG. 1 and FIG. 2, the cleaning device 2 for cleaning the wafer W as a workpiece, the chuck table 20 serving as a holding unit for holding the wafer W, and the chuck table 20 A cleaning liquid ejection unit (cleaning liquid ejection means means) 46 having a cleaning liquid ejection nozzle 50 for ejecting the cleaning liquid onto the wafer W held by the X axis, and an X-axis feed mechanism for relatively moving the cleaning liquid ejection unit 46 and the chuck table 20 in the X direction. (X-direction moving means) 14, a Y-axis feed mechanism (Y-direction moving means) 36 for moving the cleaning liquid ejection unit 46 and the chuck table 20 in the Y direction orthogonal to the X direction, and the chuck table 20 The cleaning apparatus 2 includes an imaging unit (imaging means) 54 that images the wafer W and detects a cleaning region (cutting groove M). .

Next, an embodiment of a cleaning method using the cleaning device 2 having the above configuration will be described.
In the present embodiment, the wafer W, which is the workpiece shown in FIG. 2, is cleaned, and the cutting groove M is set as a cleaning region, and other portions not including the cutting groove M are set as non-cleaning regions. .

  First, as shown in FIG. 3, a holding step of holding the wafer W that has been cut and formed with the cutting groove M by the chuck table 20 that is a holding means is performed.

  In the present embodiment, the annular frame F is held by the clamp 26, and the wafer W is sucked and held on the holding surface 24 a of the chuck table 20 via the adhesive tape T. In addition, a workpiece such as a wafer W may be held on the chuck table 20 through a support plate, or the workpiece may be directly sucked and held on the holding surface 24a of the chuck table 20. Also good.

  Next, as shown in FIG. 4, a cleaning area detection step is performed in which the wafer W held by the chuck table 20 is imaged by the imaging unit 54 that is an imaging means to detect a cutting groove M that becomes a cleaning area.

  In the present embodiment, as shown in FIG. 2, a plurality of cutting grooves M are formed in a lattice shape at a predetermined interval (pitch) along the scheduled division lines S1 and S2 orthogonal to each other. After the imaging unit 54 is positioned above one of the cutting grooves M and an image of one point of the cutting groove M is taken, another point of the cutting groove M is imaged by moving the chuck table 20, and a line connecting the two points is obtained. It is detected as a cutting groove M. In this manner, alignment (positioning) between the cutting groove M and the imaging unit 54 can be performed.

  The detection of the cutting groove M may be automatically performed by image analysis of the captured image, or may be set by a manual operation by an operator. In addition, when the cutting grooves M are formed in a lattice shape at a predetermined interval (pitch), by detecting one cutting groove M, the other cutting grooves M can be obtained by calculation. The imaging step for detecting the groove M can be omitted.

  Next, as shown in FIG. 5, the cleaning liquid ejection nozzle 50 is positioned in the cutting groove M to be the cleaning area detected in the cleaning area detection step, and the cleaning liquid is ejected onto the wafer W, and the cleaning liquid ejection nozzle 50, the chuck table 20, A cleaning step of cleaning the cutting groove M of the wafer W by performing relative movement is performed.

  By relatively moving the cleaning liquid ejection nozzle 50 and the chuck table 20, the cutting groove M is continuously cleaned in the longitudinal direction of the groove, and the cutting groove M is cleaned over the entire length.

  The cleaning liquid ejected from the cleaning liquid ejection nozzle 50 is directly applied to the cutting waste 72 in the cutting groove M, and the cutting waste 72 can be effectively washed away.

  Further, when the burr 74 is formed in the opening of the cutting groove M, it is expected that the burr 74 is removed by the cleaning liquid ejected from the cleaning liquid ejection nozzle 50.

  For example, pure water may be used as the cleaning liquid. Further, the cleaning liquid may have a high pressure (for example, 10 Mpa (plus or minus 2 Mpa)). Alternatively, two fluids of high pressure air and water (for example, water amount: 200 ml / min, air pressure: 0.4 MPa) may be ejected.

  Further, only the cleaning liquid is ejected from the cleaning liquid ejection nozzle 50, and the cleaning may be performed by mixing abrasive grains with the cleaning liquid or by ejecting only abrasive grains.

  For example, silica may be used as the abrasive grains, but is not particularly limited. In addition, as the abrasive grains, for example, those which are difficult to attack other areas that are not cleaning areas such as areas where devices are formed (for example, those that have no or less aggressiveness to damage) should be appropriately selected. Is preferred. In particular, when abrasive grains are used, it is expected that the burrs 74 can be removed more effectively.

  When the workpiece is a wafer W as shown in FIG. 2, the cleaning region has a plurality of intersecting line-shaped cleaning regions (cutting grooves M), and in the cleaning step, the cleaning liquid jet nozzle 50 moves to the wafer W. A cleaning method is implemented in which cleaning feed is relatively moved in the X direction while jetting the cleaning liquid, and indexing feed is performed by relatively moving in the Y direction orthogonal to the X direction and positioning the cleaning liquid jet nozzle 50 in each line-shaped cleaning area. Can do.

  Thus, in the apparatus configuration of FIG. 1, the cleaning feed for moving the chuck table 20 in the X direction is performed to perform cleaning for a certain cutting groove M, and then the cleaning liquid ejection nozzle 50 is indexed and fed in the Y direction. By repeating the process of cleaning the cutting groove M, cleaning can be performed for all the cutting grooves M extending along the first division line S1. After that, by rotating the chuck table 20 by 90 degrees, it is possible to clean all the cutting grooves M extending along the second scheduled dividing line S2.

  Furthermore, as shown in FIG. 6, for example, the laminate 82 on the workpiece divided into the chips 80 may be cleaned and removed by a cleaning liquid or abrasive grains ejected from the cleaning liquid ejection nozzle 50. As this laminate 82, for example, a DAF (Die Attach) stuck on a metal film layer left by plasma dicing of a wafer with a metal film or a chip divided by a DBG (Dicing Before Grinding) process. For the film), the street corresponding region (division planned line corresponding region) is set as the cleaning region 84 and the cleaning liquid 84 is ejected to remove the laminate 82 existing in the cleaning region 84.

  In this case, the laminate 82 can be removed by washing, and the workpiece can be divided into individual chips 80. In addition, as shown in FIG. 6, after the plasma dicing or DBG is completed, the adhesive tape 86 is attached to the surface opposite to the laminate 82, and the chip 80 is removed after the laminate 82 is washed and removed. It is preferable not to separate.

  In the cleaning method described above, the portion of the cutting groove M is set as a cleaning region, and the device region surrounded by the cutting groove M is set as a non-cleaning region, so that the cutting waste 72 and burrs 74 in the cutting groove M are exclusively removed. Cleaning for the purpose can be performed.

  In addition to such a cleaning method, for example, the portion of the cutting groove M is set as a non-cleaning region, and the device region surrounded by the cutting groove M is set as a cleaning region. Good.

  Furthermore, in the cleaning method described above, it is preferable to perform cleaning according to the purpose by appropriately setting the pressure and time of the cleaning liquid according to the cleaning region and the material of the workpiece. In addition, for example, it is preferable to take into account damage in a non-cleaning region such as a device region.

  As described above, according to the cleaning method of the present invention, various types of cleaning can be performed, and cleaning in the present invention refers to the removal of foreign matters on the cleaning region. 5 (contamination of foreign matter such as cutting waste 72) and removal of burrs 74 in the cutting groove M (kerf) shown in FIG. 5, and film on the street corresponding region in the wafer divided into chips 80 as shown in FIG. This includes removal (cutting) of the laminate 82 such as (metal film layer) or DAF.

2 Cleaning device 20 Chuck table 46 Cleaning liquid ejection unit 50 Cleaning liquid ejection nozzle 52 Alignment unit 54 Imaging unit 72 Cutting waste 74 Burr 80 Chip 82 Laminate 84 Cleaning area 86 Adhesive tape M Cutting groove

Claims (5)

A cleaning device for cleaning a workpiece,
Holding means for holding the workpiece;
A cleaning liquid jetting means having a cleaning liquid jet nozzle for jetting the cleaning liquid to the workpiece held by the holding means;
An X-direction moving means for relatively moving the cleaning liquid ejection means and the holding means in the X direction;
Y-direction moving means for relatively moving the cleaning liquid ejection means and the holding means in the Y direction orthogonal to the X direction;
An imaging device comprising: imaging means for imaging a workpiece held by the holding means and detecting a cleaning region. Abrasive grains are mixed in the cleaning liquid,
The cleaning apparatus according to claim 1. A cleaning method for cleaning the cleaning region of a workpiece having a cleaning region and a non-cleaning region,
A holding step of holding the workpiece by holding means;
A cleaning region detection step of detecting the cleaning region by imaging the workpiece held by the holding unit with an imaging unit;
A cleaning liquid ejection nozzle is positioned in the cleaning area detected in the cleaning area detection step to eject cleaning liquid to the workpiece, and the cleaning liquid ejection nozzle and the holding means are relatively moved to move the cleaning liquid jet nozzle to the workpiece. A cleaning step for cleaning the cleaning area;
Cleaning method with. The cleaning area has a plurality of intersecting line-shaped cleaning areas,
In the cleaning step, the cleaning liquid is ejected from the cleaning liquid ejection nozzle to the workpiece while being relatively moved in the X direction, and the cleaning liquid ejection nozzle is relatively moved in the Y direction orthogonal to the X direction. Repeat indexing and positioning located in the cleaning area
The cleaning method according to claim 3. Abrasive grains are mixed in the cleaning liquid,
The cleaning method according to claim 3 or 4, wherein

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