JP3849922B2 - Dicing machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dicing apparatus, and more particularly to a dicing apparatus that cuts a large number of chips formed on a semiconductor wafer for each chip.
[0002]
[Prior art]
The dicing apparatus holds a wafer on a cutting table, rotates the cutting table with a motor to align the wafer at a predetermined position, and then rotates the aligned wafer at a high speed (hereinafter referred to as “blade”). In this case, the wafer is cut into chips by cutting.
[0003]
The wafer cut by the dicing apparatus is generally cleaned by a spinner cleaning apparatus. For example, in a fully automatic type device in which the spinner cleaning device is mounted on the same base as the dicing device, the unfinished wafer is automatically transferred from the dicing device to the spinner cleaning device by the unloading device, where the wafer is cleaned. ing. In addition, in a semi-auto type apparatus that is not equipped with a spinner cleaning device, the operator removes the cut wafer from the cutting table, and then attaches the wafer to a spinner cleaning device provided at another location for cleaning. Yes.
[0004]
The spinner cleaning apparatus includes a rotary table that holds a wafer, a nozzle that jets cleaning water such as pure water onto the wafer, and the like. In this spinner cleaning apparatus, the wafer is cleaned by the cleaning water sprayed from the nozzle while rotating by the rotation of the rotary table.
[0005]
However, in the above-mentioned conventional apparatus, the wafer cut by the dicing apparatus is transferred to the spinner cleaning apparatus for cleaning, regardless of whether it is a full-auto type or a semi-auto type, so that it takes time to transfer the wafer and improves the processing efficiency of the wafer. There was a drawback that it was not possible.
[0006]
For this reason, a dicing apparatus has been proposed in which cleaning water jetting means constituting the spinner cleaning apparatus is provided in the dicing apparatus, and the alignment motor of the dicing apparatus is also used as a motor for rotating the rotary table of the spinner cleaning apparatus (special feature). Open 2000-188268). Thereby, the conveyance process which conveys the wafer after a cutting | disconnection to a spinner cleaning apparatus is abbreviate | omitted.
[0007]
However, in this dicing apparatus, since a direct drive motor used for alignment at the time of wafer cutting is also used for spinner cleaning as a dual-purpose motor, even if it is rotated at a high speed during spinner cleaning (for example, 600 rpm), the direct drive motor As a result, the number of rotations of the motor is absolutely insufficient, and the cleaning tends to be insufficient.
[0008]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and efficiently performs the wafer cutting process and the wafer cleaning process performed thereafter, and the dicing capable of rotating the table at a high speed during the cleaning process. An object is to provide an apparatus.
[0009]
[Means for Solving the Problems]
The present invention of claim 1 is a dicing apparatus,
A table that holds the wafer to be cut and also holds the wafer when the wafer after cutting is cleaned by a spinner;
An alignment means comprising a first motor that is a hollow motor that rotates the table during alignment during wafer cutting;
A cutting means comprising a cutting blade for cutting the wafer aligned by the alignment means;
A cleaning water spraying device that sprays cleaning water onto the wafer held by the table, and a second motor that is disposed coaxially with the first motor in the hollow portion of the first motor and rotates the table during cleaning. And cleaning means comprising:
Contact and separation means for connecting the first motor to the table and releasing the connection by moving the second motor up and down;
When the wafer is cut, the second motor is moved downward by the contact / separation means, so that the first motor is connected to the table to rotate the table, and at the time of spinner cleaning, the second motor is moved by the contact / separation means. By moving upward, the connection of the first motor to the table is released, and the second motor rotates the table at a high speed.
[0010]
According to the first aspect of the present invention, the cleaning water jetting device constituting the spinner cleaning device is provided in the dicing device, and the table for holding the wafer is made common for cutting and cleaning so that the wafer is placed on the table at the time of cutting. Since the cleaning water is sprayed onto the cut wafer from the cleaning water spraying device while being held, the transporting process of transporting the cut wafer to the spinner cleaning device can be omitted. Furthermore, a total of two motors were used: a first motor that rotates the table during wafer cutting and a second motor that rotates the table during spinner cleaning. Since the first motor is connected to the table or released by moving the second motor up and down according to the time of cutting and cleaning, the first motor suitable for positioning can be used when cutting the wafer. A second motor suitable for high-speed rotation can be used during spinner cleaning. Therefore, positioning can be performed with high accuracy, and cleaning can be performed effectively by rotating the table at a high speed.
[0011]
According to the second aspect of the present invention, when the wafer is cut, the spring is energized to cause the spring to act like a coil so that a magnetic field is applied to the bracket. As a result, the second motor is lowered and the first motor is moved to the table. Connect to and rotate the table. When the wafer is cleaned, if the spring is not energized, the second motor is lifted by the urging force of the spring, so that the connection between the first motor and the table is released and the second motor rotates the table.
[0012]
According to the third aspect of the present invention, by using the servo motor as the second motor, the table can be rotated at a high speed, and the cleaning function can be enhanced.
[0013]
According to the fourth aspect of the present invention, the surface of the wafer that has been cleaned is imaged, and the image that has been captured is subjected to signal processing to confirm the cleaning state.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a dicing apparatus according to the present invention will be described in detail with reference to the accompanying drawings.
[0015]
FIG. 1 is a perspective view of a dicing apparatus 10 according to an embodiment of the present invention, FIG. 2 is a longitudinal sectional view of the dicing apparatus 10 shown in FIG. 1 when cut, and FIG. 3 is a diagram of the dicing apparatus 10 shown in FIG. It is a longitudinal cross-sectional view at the time of washing | cleaning.
[0016]
The dicing apparatus 10 shown in these drawings finely aligns a wafer 14 sucked and held on a cutting table (corresponding to a cutting table) 12 by an alignment apparatus including a hollow motor 16 and an imaging device (or a microscope) 18. Thereafter, the wafer 14 is cut into a dice with a blade 22 that rotates at a high speed while the wafer 14 is moved in the X direction by the XY movement mechanism 20. Further, at the time of cutting the wafer 14, in order to maintain the processing accuracy of the wafer 14, a processing liquid is sprayed from a nozzle (not shown) toward the blade 22 during wafer cutting.
[0017]
As shown in FIG. 1, the blade 22 is attached to a spindle 26 of a blade motor 24 and is rotated at high speed by the driving force of the blade motor 24. The blade 22 is covered with a flange cover (not shown) except for the cut portion. A nozzle for injecting the machining fluid is attached to the flange cover.
[0018]
As shown in FIG. 2, a recess 13 is formed on the upper surface of the cutting table 12, and a porous material 28 made of a sintered body such as ceramic is attached to the recess 13. The porous material 28 is formed in a disk shape corresponding to the shape of the wafer 14 having a disk shape, and the upper surface thereof is flush with the upper surface of the cutting table 12. As a result, the entire surface of the wafer 14 is held on the upper surface of the cutting table 12. A through hole 30 is formed at a position corresponding to the rotation center A of the cutting table 12, and the through hole 30 is connected to the lower surface of the porous material 28. The through hole 30 is connected to a suction tube 96 that sucks and holds the wafer 14.
[0019]
The suction pipe 96 extends outside the dicing apparatus 10 and is connected to the suction pump 42 via the vacuum break valve 40. Therefore, when the suction pump 42 is driven and the vacuum break valve 40 is closed, the wafer 14 is vacuum-adsorbed on the porous material 28. When the vacuum break valve 40 is opened, the suction pipe 96 is opened to the atmosphere, so that the vacuum suction holding of the wafer 14 by the porous material 28 is released. A flange 44 having an L-shaped cross section is attached to the peripheral portion of the cutting table 12. The flange 44 receives a wafer frame (unnecessary portion excluding chips) generated by the wafer cutting, so that the wafer frame is prevented from falling off the cutting table 12.
[0020]
On the upper surface of the hollow motor 16, a suction groove 106 for closely connecting the hollow motor 16 and the cutting table 12 is formed. The groove 106 vacuum-sucks the upper surface of the cutting table 12 and the hollow motor 16 by piping (not shown). When the vacuum breaker valve 40 is opened, the suction pipe 96 is opened to the atmosphere, so that the vacuum suction holding of the hollow motor 16 by the cutting table 12 is released. A long groove 108 is formed around the upper part of the side surface of the hollow motor 16. An L-shaped portion 110 extends from the lower surface of the cutting table 12 so that the tip enters the long groove 108.
[0021]
The hollow motor 16 has a cylindrical shape in which a hollow portion is formed in a shaft portion, and has a structure in which the cylindrical portion 17 rotates.
[0022]
By the way, cleaning water injection nozzles 56 and 56 constituting the cleaning water injection device 54 are provided on both the left and right sides of the blade 22. These nozzles 56 are fixed to a flange cover (not shown) that covers the blade 22. Further, as shown in FIG. 1, a cleaning water supply pipe 58 is connected to the nozzles 56, 56, and this supply pipe 58 is connected to a cleaning water tank 64 through a water supply pump 62 and a shutoff valve 60. Therefore, when the shut-off valve 60 is opened and the water supply pump 62 is driven, the cleaning water 66 stored in the tank 64 is supplied to the nozzles 56 and 56 through the cleaning water supply pipe 58, and is supplied from the nozzles 56 and 56. Injected toward the wafer 14. The wafer 14 is cleaned by cleaning water sprayed from the nozzles 56 and 56.
[0023]
A servo motor 90 is disposed coaxially with the hollow motor 16 in the hollow portion of the hollow motor 16. The servo motor 90 is housed and disposed inside a substantially cylindrical fixed cylinder 99 having an opening on the upper surface so that a cylindrical iron bracket 98 protrudes from the fixed cylinder 99. An iron spring 100 is wound around the portion where the part is located. Therefore, about two-thirds of the lower side in the vertical direction of the bracket 98 can move up and down in the fixed cylinder 99 while receiving the urging force of the spring 100 via the spring 100.
[0024]
Inside the bracket 98, a rotor 92 of a servo motor for spinner cleaning is disposed.
[0025]
A connection member 112 that connects the rotor 92 and the cutting table 12 is attached to the upper portion of the rotor 92. By this connecting member 112, the cutting table 12 is rotated when the rotor 92 is rotated.
[0026]
The rotor 92 is connected to the coupling 102. The coupling 102 is always connected. A rotating shaft 95 is further connected to the lower side of the coupling 102, and the rotating shaft 95 is rotatably attached to the bracket 98.
[0027]
A connecting portion between the rotary shaft 91 and the pair of overhanging tubes 94 is sealed with a seal member 97.
[0028]
Next, the operation of the dicing apparatus 10 configured as described above will be described with reference to the block diagram shown in FIG.
[0029]
The control device 68 in FIG. 4 is a CPU that controls the entire dicing device 10. The control device 68 is a hollow motor based on operation switching information from a cutting / cleaning operation changeover switch 70 attached to the dicing device 10. 16, the servo motor 90, the spring 100, the imaging device 18, the XY movement mechanism 20, the blade motor 24, the vacuum breaker valve 40, the cleaning water injection device 54, and the like are controlled.
[0030]
Usually, processing steps are in the order of cutting and cleaning.
[0031]
First, a cutting process is performed. When a cutting operation signal is output from the cutting / cleaning operation switch 70, the cutting process is started. The initial cutting process will be described with reference to the flowchart of FIG. First, it is confirmed that the cutting table 12 is in the lowered position (step 120). Whether or not the cutting table 12 is in the lowered position uses a sensor (not shown) that senses table vacuum. The position of the cutting table 12 can be determined by using an encoder (not shown) provided in the servo motor 90. When in the lowered position, that is, in the state shown in FIG. 2, since the cutting table 12 is in contact with the upper surface of the hollow motor 16, the control device 68 closes the vacuum break valve 40 (step 122). The wafer 14 is held by vacuum suction on the cutting table 12. Thereafter, the hollow motor 16 and the imaging device 18 which are alignment devices of the dicing device 10 are driven (step 124), and the wafer 14 on the cutting table 12 is rotated by the hollow motor 16 while being observed by the imaging device 18. Thus, the wafer 14 is finely aligned at a predetermined position.
[0032]
Thereafter, the cutting process is started. The controller 68 drives the XY movement mechanism 20 to drive the blade motor 24 while moving the wafer 14 in the X direction, and cuts the wafer 14 into dice with the blade 22 rotating at high speed. Examples of the cutting method include a circular cutting method and a square cutting method.
[0033]
When the cutting process of the wafer 14 by the blade 22 is completed, the control device 68 stops the hollow motor 16, the imaging device 18, and the blade motor 24.
[0034]
If the cutting table 12 is not in the lowered position in step 120, the spring 100 is in the extended position, that is, the servo motor 90 is in the raised position (the state shown in FIG. 3), and a current is passed through the spring 100 (step 126). . When a current is passed through the spring 100, the spring 100 becomes an electromagnet, and the bracket 98 is made of a magnetic material, so that the spring 100 is lowered. When it is confirmed that the cutting table 12 has come to the lowered position (step 128), since the cutting table 12 is in contact with the upper surface of the hollow motor 104, the vacuum break valve 40 is closed (step 130), and the wafer 14 is moved. Vacuum cutting is held on the cutting table 12. Then, the current to the spring 100 is turned off (step 132). Thereafter, the hollow motor 16 and the imaging device 18 which are alignment devices of the dicing device 10 are driven (step 134), and the wafer 14 on the cutting table 12 is rotated by the hollow motor 16 while being observed by the imaging device 18. Thus, the wafer 14 is finely aligned at a predetermined position.
[0035]
Since the subsequent cutting process is the same as the above-described cutting process, description thereof is omitted.
[0036]
Next, a cleaning process is performed. When a cleaning operation signal is output from the cutting / cleaning operation switch 70, the cleaning process is started. The initial cleaning process will be described with reference to the flowchart of FIG. First, it is confirmed whether or not the cutting table 12 is in the raised position (step 136). Whether or not it is in the ascending position is confirmed by sensing with a vacuum sensor (not shown). If the spring 100 is energized or the vacuum breaker valve 40 is closed, the cutting table 12 is not in the raised position, so the spring 100 is deenergized or the vacuum breaker valve 40 is opened ( Step 138). Since the action of keeping the bracket 98 in the lowered position is released by releasing the energization of the spring 100 and opening the vacuum break valve 40, the bracket 98 is urged upward by the urging force of the spring 100, and the cutting table 12. Is moved to the raised position. Even if the cutting table 12 is vigorously moved upward by the urging force of the spring 100, the leading end of the L-shaped portion 110 hits the long groove 108, so that the cutting table 12 does not come out of the hollow motor 16.
[0037]
When it is confirmed that the cutting table 12 is in the raised position, the control device 68 closes the vacuum break valve 40 and causes the porous material 28 to hold the wafer 14 by vacuum suction (step 140).
[0038]
Thereafter, the cleaning process is started. The control device 68 drives the servo motor 90 and the cleaning water injection device 54, and cleans the wafer 14 from the cleaning water injection nozzles 56 and 56 while rotating the cutting table 12 at a high speed (for example, 3000 rpm) by the servo motor 90. Water is sprayed to start cleaning of the wafer 14, that is, spinner cleaning. At this time, the control device 68 drives the XY moving mechanism 20 to move the cutting table 12 intermittently or continuously in the XY direction. Thereby, the entire surface of the wafer 14 is thoroughly cleaned with the cleaning water. Normally, when the table is rotated at a high speed, the cutting table 12 is vibrated. However, since the spring 100 absorbs the vibration and plays the role of vibration isolation, the vibration of the table 12 is small in this embodiment.
[0039]
And when the said spinner washing | cleaning passes for the predetermined time, the control apparatus 68 will once stop the servomotor 90, the washing water injection apparatus 54, and the XY movement mechanism 20. FIG. Then, the control device 68 drives the imaging device 18 to image the surface of the wafer 14 and confirms the cleaning status of the wafer 14. At this time, the control device 68 drives the XY movement mechanism 20 and moves the cutting table 12 in the XY direction, thereby causing the imaging device 18 to image the entire surface of the wafer 14.
[0040]
When it is determined that the cleaning of the wafer 14 is insufficient, the spinner cleaning is performed again. The determination may be made by an operator of the dicing apparatus 10 or may be made to make a self-determination with the dicing apparatus 10. When the operator makes a determination, the image picked up by the image pickup device 18 is displayed on a display device such as a display and is visually observed. Further, when the dicing device 10 makes a self-determination, the image signal picked up by the image pickup device 18 is subjected to signal processing (for example, binarization processing with a threshold value indicating that it has been sufficiently washed).
[0041]
On the other hand, when it is determined that the wafer 14 has been sufficiently cleaned, the control device 68 drives the servo motor 90 and stops the cleaning water jet device 54 to rotate the wafer 14 at high speed to dry it. Thus, the cutting process and the cleaning / drying process for the wafer 14 are completed.
[0042]
As described above, according to the dicing apparatus 10 of the present embodiment, the cleaning water injection device 54 is provided in the dicing apparatus 10, and the table holding the wafer 14 is shared between the cutting time and the cleaning time so that the table at the time of cutting is used. Since the cleaning water is jetted from the cleaning water jetting device 54 to the cut wafer while the wafer is held, the transporting process of transporting the cut wafer 14 to the spinner cleaning device can be omitted. Thereby, according to the said dicing apparatus 10, since the cutting process and washing | cleaning process of the wafer 14 can be implemented efficiently and also the drying process can be performed at high-speed rotation, the processing efficiency of the wafer 14 can be improved. .
[0043]
Furthermore, a total of two motors, a hollow motor 16 that rotates the table during wafer cutting and a servo motor 90 that rotates the table during spinner cleaning, are used, and the spring 100 moves the servo motor 90 up and down according to cleaning during cutting and cleaning. Since the hollow motor 16 is connected to or disconnected from the cutting table 12, the hollow motor 16 suitable for positioning can be used when cutting the wafer 14, and the servo motor 90 suitable for high-speed rotation is used when cleaning the spinner. be able to. Therefore, positioning can be performed with high accuracy, and cleaning can be performed strongly by rotating the table at a high speed. Further, the spring 100 also serves to prevent vibration of the cutting table 12 during high-speed rotation.
[0044]
Furthermore, according to the dicing apparatus 10, since the cleaning state of the wafer 14 is confirmed by the imaging device 18 of the alignment apparatus, it is not necessary to separately provide a dedicated device for confirming the cleaning state. The status can be easily confirmed.
[0045]
Needless to say, the dicing apparatus 10 described in the present embodiment can be applied to either a full-auto type dicer or a semi-auto type dicer.
[0046]
【The invention's effect】
According to the dicing apparatus according to the first aspect of the present invention, since the cleaning water jetting apparatus constituting the spinner cleaning apparatus is provided in the dicing apparatus, the wafer cutting process and the cleaning process can be efficiently performed. Wafer processing efficiency can be improved. Further, the table can be accurately positioned during cutting, and the table can be cleaned cleanly by rotating the table at a high speed.
[0047]
According to the second aspect of the present invention, since the spring functions as a coil, two types of motors can be connected to the table according to the purpose of cutting and cleaning with a simple structure, and high-speed rotation is possible. Inside, the spring also plays the role of anti-vibration.
[0048]
According to the third aspect of the present invention, the table can be rotated at a high speed, and a strong cleaning function can be obtained.
[0049]
According to the fourth aspect of the present invention, since the cleaning state can be automatically confirmed, it is possible to accurately evaluate the cleaning state without variation, rather than checking the cleaning state with human intervention.
[Brief description of the drawings]
FIG. 1 is a perspective view of a dicing apparatus according to an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of the dicing apparatus shown in FIG. 1 when cut.
FIG. 3 is a longitudinal sectional view of the dicing apparatus shown in FIG. 1 during cleaning.
4 is a block diagram showing a control system of the dicing apparatus shown in FIG. 1. FIG.
FIG. 5 is a flowchart showing an initial cutting process.
FIG. 6 is a flowchart showing an initial process of cleaning.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Dicing apparatus, 12 ... Cutting table, 14 ... Wafer, 16 ... Hollow motor, 18 ... Imaging device, 20 ... XY movement mechanism, 22 ... Blade, 32 ... Rotor, 46 ... Stator, 48 ... Coil, 54 ... Washing water injection device, 68 ... control device, 90 ... servo motor, 98 ... bracket, 100 ... spring, 112 ... connecting member

Claims (4)

A dicing machine,
A table that holds the wafer to be cut and also holds the wafer when the wafer after cutting is cleaned by a spinner;
An alignment means comprising a first motor that is a hollow motor that rotates the table during alignment during wafer cutting;
A cutting means comprising a cutting blade for cutting the wafer aligned by the alignment means;
A cleaning water spraying device that sprays cleaning water onto the wafer held by the table, and a second motor that is disposed coaxially with the first motor in the hollow portion of the first motor and rotates the table during cleaning. And cleaning means comprising:
Contact and separation means for connecting the first motor to the table and releasing the connection by moving the second motor up and down;
When the wafer is cut, the second motor is moved downward by the contact / separation means, so that the first motor is connected to the table to rotate the table, and at the time of spinner cleaning, the second motor is moved by the contact / separation means. The dicing apparatus, wherein the first motor is disconnected from the table by moving upward and the second motor rotates the table at a high speed. The contact / separation means includes a bracket formed of a magnetic material forming an outer wall of the second motor and a spring wound around the outer wall of the second motor to cause the vertical movement of the second motor. When the wafer is cut, the spring becomes an electromagnet by energizing the spring, and when the second motor is lowered by pulling the bracket, the first motor is connected to the table to rotate the table. The said 2nd motor raises with the urging | biasing force of a spring, The connection of a said 1st motor and the said table is cancelled | released, The said 2nd motor comes to rotate the said table. Dicing equipment.   The dicing apparatus according to claim 1, wherein the second motor is a servo motor capable of rotating at a high speed.   2. The dicing apparatus according to claim 1, wherein the cleaning means includes an image signal processing device for monitoring a cleaning state.

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