JP5108724B2 - Electrode processing equipment - Google Patents

Description

  The present invention relates to an electrode processing apparatus for turning bumps (electrodes) provided on a plurality of devices formed on the surface of a wafer such as a semiconductor wafer.

A semiconductor wafer in which a plurality of semiconductor devices are formed is divided into individual semiconductor devices by a dicing apparatus or the like, and the divided semiconductor devices are widely used in electric devices such as mobile phones and personal computers.
In recent years, in order to reduce the weight and size of electrical equipment, bumps of 50 to 100 μm are formed on the electrodes of semiconductor devices, and these bumps (electrodes) are directly bonded to the electrodes formed on the mounting substrate. A semiconductor device called a flip chip has been developed and put into practical use. In addition, a technique for reducing the size by mounting a plurality of semiconductor devices on a substrate called an interposer or stacking them has been developed and put into practical use. Each of these technologies forms a plurality of bumps (electrodes) on the surface of the semiconductor device and bonds the substrates to each other via the bumps, so that the height of the bumps (electrodes) is high. It is necessary to align.

  On the other hand, as a technique for forming a plurality of bumps (electrodes) on the surface of a semiconductor device, the tip of a wire such as gold is heated and melted to form a ball, and then the ball is applied to the electrode of a semiconductor chip. A method of thermocompression bonding with sound waves to break the head of the ball, a method of growing bumps (electrodes) by plating, a method of joining small spheres made of metal with ultrasonic waves, and the like have been put into practical use. However, in these electrode forming methods, it is difficult to form a plurality of bumps (electrodes) with the same height.

As a processing method for aligning a plurality of protruding bumps (electrodes) formed on the surface of a semiconductor device, there has been proposed a method of turning and removing tip portions of a plurality of electrodes with a rotating tool. (For example, refer to Patent Document 1.)
JP 2004-319697 A

  Thus, even if the tips of the plurality of bumps (electrodes) are evenly aligned, if the height of the surface of the device formed on the wafer varies, the length of the bumps (electrodes) varies. When variations in the length of bumps (electrodes) occur, devices such as memories and LEDs have subtle deviations in electrical performance such as electrical resistance, electrical capacity, and conduction speed, which impairs device functionality. The facts turned out.

  The present invention has been made in view of the above-described facts, and the main technical problem thereof is that a plurality of devices formed on each device have a variation in the height of the surfaces of the devices formed on the wafer. An object of the present invention is to provide an electrode processing apparatus capable of uniformly turning the length of a bump (electrode) from the surface of a device.

In order to solve the above-mentioned main technical problem, according to the present invention, a chuck table having a holding surface parallel to the X-axis direction and the Y-axis direction orthogonal to the X-axis direction, and a movable base for supporting the chuck table A chuck table mechanism comprising: a turning means for turning a plurality of protruding electrodes respectively provided on a plurality of devices formed on a surface of a wafer held on a holding surface of the chuck table; In an electrode machining apparatus comprising: a machining feed unit that feeds a moving base to the turning unit in parallel with the holding surface of the chuck table;
The chuck table is supported via a piezo motor that is disposed between the moving base and is configured by a piezoelectric element that is displaced in a direction perpendicular to the holding surface.
The turning means includes a rotary spindle disposed in a direction perpendicular to the holding surface of the chuck table, a bite mounting substrate mounted on a lower end of the rotary spindle, and the bite mounting substrate decentered from an axis. A turning tool arranged in a position,
Chuck table position detecting means for detecting the movement position of the chuck table;
A tool position detecting means for detecting a rotational position of the cutting tool in the turning means;
Control means for controlling the piezo motor based on detection signals from the chuck table position detection means and the bite position detection means,
The control means includes a memory for storing the X and Y coordinate values of a plurality of devices formed on the surface of the wafer and the surface height positions of the devices detected in advance, and the turning tool is rotated by rotating the turning tool. X and Y coordinate values are obtained and applied to the piezo motor corresponding to the surface height position of the device at the X and Y coordinate values of the device when the turning tool passes through the X and Y coordinate values of each device. Control the voltage,
An electrode processing apparatus is provided.

  In the electrode processing apparatus according to the present invention, the chuck table is supported by a piezoelectric motor that is disposed between the moving base and is displaced by a piezoelectric element that is displaced in a direction perpendicular to the holding surface. Turning means for turning a plurality of protruding electrodes respectively provided on a plurality of devices formed on the surface of the wafer held on the surface is disposed in a direction perpendicular to the holding surface of the chuck table. A rotating spindle, a cutting tool mounting board mounted on the lower end of the rotating spindle, and a turning tool disposed on the cutting tool mounting board at a position eccentric from the axis, and a control means is formed on the surface of the wafer. In addition, it is equipped with a memory that stores the X and Y coordinate values of multiple devices and the surface height position of the device detected in advance, and turning by turning a turning tool The voltage applied to the piezo motor corresponding to the surface height position in the X and Y coordinate values of the device when the turning tool passes through the X and Y coordinate values of each device. Therefore, the length of the plurality of bumps (electrodes) formed on the surface of each device can be uniformly turned from the device surface.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of an electrode processing apparatus configured according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view of an electrode processing apparatus constructed according to the present invention.
The electrode processing apparatus in the illustrated embodiment includes an apparatus housing generally designated by reference numeral 2. The apparatus housing 2 has a rectangular parallelepiped main portion 21 that extends elongated and an upright wall 22 that is provided at the rear end portion (upper right end in FIG. 1) of the main portion 21 and extends upward. A pair of guide rails 221 and 221 extending in the vertical direction are provided on the front surface of the upright wall 22. A turning unit 3 as a turning means is mounted on the pair of guide rails 221 and 221 so as to be movable in the vertical direction.

  The turning unit 3 includes a moving substrate 31 and a spindle unit 32 attached to the moving substrate 31. The movable substrate 31 is provided with a pair of legs 311 and 311 extending in the vertical direction on both sides of the rear surface, and the pair of legs 311 and 311 are slidably engaged with the pair of guide rails 221 and 221. Guided grooves 312 and 312 are formed. A support member 313 is mounted on the front surface of the movable substrate 31 slidably mounted on the pair of guide rails 221 and 221 provided on the upright wall 22 as described above, and the spindle unit 32 is attached to the support member 313. . The spindle unit 32 will be described with reference to FIG.

  A spindle unit 32 shown in FIG. 2 includes a spindle housing 321, a rotating spindle 322 rotatably disposed in the spindle housing 321, and the rotating spindle 322. The spindle housing 321 is formed in a substantially cylindrical shape and includes a shaft hole 321a penetrating in the axial direction. The spindle housing 321 is disposed so that its axial direction is perpendicular to the holding surface of the chuck table, which will be described later. A rotary spindle 322 that is inserted through a shaft hole 321a formed in the spindle housing 321 is provided with a thrust bearing flange 322a that protrudes in the radial direction at the center. In this way, the rotary spindle 322 disposed through the shaft hole 321a formed in the spindle housing 321 is rotatably supported by high-pressure air supplied between the inner wall of the shaft hole 321a.

  A tool mounting mount 323 is attached to the lower end of the rotary spindle 322, and a tool mounting substrate 33 is mounted on the tool mounting mount 323 with fastening bolts 330. The tool mounting substrate 33 is formed in a disk shape, and a tool mounting hole 331 is provided at a position eccentric from the axis by a radius (r). The distance (radius (r)) from this axial center to the bite mounting hole 331 is set to a value longer than the radius of the wafer that is a workpiece to be held on the chuck table described later. Thus, the turning tool 34 is disposed in the tool mounting hole 331 formed in the tool mounting board 33. The turning tool 34 is detachably mounted on the tool mounting board 33 by screwing a fastening bolt 35 into a female screw hole (not shown) provided on the outer peripheral portion of the tool mounting board 33 and tightening it. The turning tool 34 is composed of a tool body 341 formed in a rod shape with tool steel such as super steel alloy, and a cutting blade 342 formed of diamond or the like provided at the lower end of the tool body 341. It is used. The turning tool 34 mounted on the tool mounting board 33 mounted on the tool mounting mount 323 configured in this way is in a plane parallel to the holding surface of the chuck table, which will be described later, as the rotating spindle 322 rotates. Can be rotated.

  Continuing the description with reference to FIG. 2, the illustrated spindle unit 32 includes an electric motor 36 for rotationally driving the rotary spindle 322. The illustrated electric motor 36 is a permanent magnet motor. The permanent magnet type electric motor 36 is disposed in a spindle housing 321 on the outer peripheral side of the rotor 361 and a rotor 361 composed of a permanent magnet mounted on a motor mounting portion 322 b formed in an intermediate portion of the rotary spindle 22. It consists of a stator coil 362. The electric motor 36 configured as described above rotates the rotor 361 by applying AC power to the stator coil 362 by power supply means (not shown), and rotates the rotating spindle 322 to which the rotor 361 is mounted.

  The illustrated spindle unit 32 is provided with a tool position detecting means 37 for detecting the rotational position of the turning tool 342. The byte position detection means 37 is a rotary encoder, and sends the detection signal to the control means described later.

  Referring back to FIG. 1, the machining apparatus in the illustrated embodiment moves the turning unit 3 up and down along the pair of guide rails 221 and 221 (in a direction perpendicular to a mounting surface of a chuck table described later). ) Is provided with a turning unit feed mechanism 4. The turning unit feed mechanism 4 includes a male screw rod 41 disposed on the front side of the upright wall 22 and extending in the vertical direction. The male screw rod 41 is rotatably supported by bearing members 42 and 43 whose upper end and lower end are attached to the upright wall 22. The upper bearing member 42 is provided with a pulse motor 44 as a drive source for rotationally driving the male screw rod 41, and the output shaft of the pulse motor 44 is connected to the male screw rod 41 by transmission. A connecting portion (not shown) is formed on the rear surface of the movable substrate 31 so as to protrude rearward from the central portion in the width direction, and a through female screw hole extending in the vertical direction is formed in the connecting portion. The male screw rod 41 is screwed into the female screw hole. Accordingly, when the pulse motor 44 is rotated forward, the moving substrate 31, that is, the turning unit 3 is lowered or advanced, and when the pulse motor 44 is reversed, the movable substrate 31, that is, the turning unit 3 is raised or retracted.

  1 and FIG. 3, a substantially rectangular machining work portion 211 is formed on the rear half of the main portion 21 of the housing 2, and the machining work portion 211 includes a chuck table mechanism. 5 is disposed. The chuck table mechanism 5 includes a moving base 51 and a disk-shaped chuck table 52 disposed on the moving base 51. The moving base 51 is a pair of guide rails extending in the processing feed direction (X-axis direction) indicated by arrows X1 and X2 which are the front-rear direction (direction perpendicular to the front surface of the upright wall 22) on the processing work unit 211. 1 and the workpiece feeding / unloading area 24 shown in FIG. 1 (position indicated by a solid line in FIG. 3) and the spindle unit 32. The turning tool 34 is moved between the turning tool 34 and the machining area 25 (position indicated by a two-dot chain line in FIG. 3).

  The chuck table 52 has a holding surface 52a parallel to the X-axis direction and the Y-axis direction orthogonal to the X-axis direction on the upper surface, and is disposed on the moving base 51 as shown in FIG. The upper surface of the support member 510 is supported via a plurality of piezo motors 53 constituted by piezoelectric elements that are displaced in a direction perpendicular to the holding surface 52a. The plurality of piezo motors 53 are connected to voltage application means 55 controlled by control means to be described later. The chuck table 52 is made of an appropriate porous material such as porous ceramics, and is connected to suction means (not shown). Accordingly, the workpiece placed on the holding surface 52a is sucked and held by selectively communicating the chuck table 52 with a suction means (not shown). The illustrated chuck table mechanism 5 includes a cover member 54 that has a hole through which the chuck table 52 is inserted, covers the moving base 51 and the like, and is movably disposed with the moving base 51.

  Here, the relationship between the voltage value applied to the piezo motor 53 constituted by the piezoelectric element and the displacement of the chuck table 52 will be described with reference to the control map shown in FIG. In FIG. 5, the horizontal axis represents the voltage value (V) applied to the piezo motor 53, and the vertical axis represents the amount of displacement in the axial direction of the chuck table 52 (direction perpendicular to the holding surface 52a). The control map shown in FIG. 5 shows an example in which the chuck table 52 is displaced by 0.5 μm with respect to a voltage of 1 V applied to the piezo motor 53.

  Continuing with reference to FIG. 3, the machining apparatus in the illustrated embodiment shows the chuck table mechanism 5 by arrows X1 and X2 along a pair of guide rails 23 arranged along the X-axis direction. A machining feed means 56 for moving in the machining feed direction is provided. The processing feed means 56 includes a male screw rod 561 disposed between the pair of guide rails 23 and 23 and extending in parallel with the guide rails 23 and 23, and a servo motor 562 that rotationally drives the male screw rod 561. The male screw rod 561 is screwed into a screw hole 511 provided in the moving base 51, and its tip is rotatably supported by a bearing member 563 disposed between the pair of guide rails 23, 23. Yes. The servo motor 562 has a drive shaft connected to the base end of the male screw rod 561 by transmission. Accordingly, when the servo motor 562 rotates in the forward direction, the moving base 51, that is, the chuck table mechanism 5 moves in the direction indicated by the arrow X1, and when the servo motor 562 rotates in the reverse direction, the moving base 51, that is, the chuck table mechanism 5 moves in the direction indicated by the arrow X2. It can be moved.

  The machining apparatus in the illustrated embodiment includes a chuck table position detection unit 57 for detecting the movement position of the chuck table mechanism 5 in the X-axis direction by the machining feed unit 56. The chuck table position detecting means 57 includes a linear scale 571 disposed along the guide rail 23 and a reading head 572 that moves along the linear scale 571 together with the moving base 51. The reading head 572 of the chuck table position detecting means 57 sends a pulse signal of one pulse every 1 μm to the control means described later in the illustrated embodiment.

  Returning to FIG. 1, the description will be continued. On the both sides of the moving base 51 constituting the chuck table mechanism 5 in the moving direction, as shown in FIG. Bellows means 57 and 58 covering the rails 23 and 23, the male screw rod 561, the servo motor 562 and the like are attached. The bellows means 57 and 58 can be formed from any suitable material such as campus cloth. The front end of the bellows means 57 is fixed to the front wall of the processing unit 211, and the rear end is fixed to the front end surface of the cover member 54 of the chuck table mechanism 5. The front end of the bellows means 58 is fixed to the rear end surface of the cover member 54 of the chuck table mechanism 5, and the rear end is fixed to the front surface of the upright wall 22 of the apparatus housing 2. When the chuck table mechanism 5 is moved in the direction indicated by the arrow X1, the bellows means 57 is expanded and the bellows means 58 is contracted, and when the chuck table mechanism 5 is moved in the direction indicated by the arrow X2, the bellows means. 57 is contracted and the bellows means 58 is extended.

  The description will be continued based on FIG. 1. On the front half of the main portion 21 of the apparatus housing 2, a first cassette mounting portion 11 a, a second cassette mounting portion 12 a, and a workpiece temporary storage portion are provided. 13a and a cleaning unit 14a are provided. A first cassette 11 that accommodates the workpiece before processing is placed on the first cassette placement portion 11a, and a second cassette that accommodates the workpiece after processing is placed on the second cassette placement portion 12a. The cassette 12 is placed. The workpiece temporary placement section 13a temporarily places a workpiece temporary placement means for temporarily placing the workpiece before being carried out from the first cassette 11 placed on the first cassette placement portion 11a. 13 is disposed. The cleaning unit 14a is provided with cleaning means 14 for cleaning the processed workpiece.

  A workpiece conveying means 15 is disposed between the first cassette placing portion 11a and the second cassette placing portion 12a, and the workpiece conveying means 15 serves as the first cassette placing portion 15a. The unprocessed workpiece housed in the first cassette 11 placed on the part 11a is carried out to the workpiece temporary storage means 13 and the processed workpiece cleaned by the cleaning means 14 is used as the first workpiece. It is transported to the second cassette 12 placed on the second cassette placement section 12a. A workpiece carry-in means 16 is disposed between the workpiece temporary placement portion 13a and the workpiece carry-in / out area 24. The workpiece carry-in means 16 serves as a workpiece. The unprocessed workpiece placed on the temporary placing means 13 is transferred onto the chuck table 52 of the chuck table mechanism 5 positioned in the workpiece loading / unloading area 24. A workpiece unloading means 17 is disposed between the workpiece loading / unloading area 24 and the cleaning unit 14a, and the workpiece unloading means 17 is a workpiece loading / unloading area. The processed workpiece placed on the chuck table 52 positioned at 24 is conveyed to the cleaning means 14.

  The processing apparatus in the illustrated embodiment includes a control means 8 shown in FIG. The control means 8 includes a central processing unit (CPU) 81 that performs arithmetic processing according to a control program, a read-only memory (ROM) 82 that stores a control program and the like, a control map shown in FIG. 5 and a surface of a semiconductor wafer described later. Read / write random access memory (RAM) 83 as storage means for storing X, Y coordinate values, surface height (Z), calculation results, and the like of a plurality of formed devices, an input interface 84 and an output interface 85. The input interface 84 of the control means 8 configured as described above receives detection signals from the byte position detection means 37, the reading head 572 of the chuck table position detection means 57, etc. Electric motor 35, pulse motor 44 of turning unit feed mechanism 4, voltage application means 55, servo motor 562 of work feed means 56, work piece temporary placement means 13, cleaning means 14, work piece transport means 15, work piece A control signal is output to the article carry-in means 16, the work-piece carry-out means 17, and the like.

  In the first cassette 11, a semiconductor wafer 10 shown in FIGS. 7A and 7B is accommodated as a workpiece before processing. The semiconductor wafer 10 shown in FIGS. 7A and 7B is made of a silicon wafer, and a plurality of devices 110 are formed on the surface 10a in a lattice shape. A plurality of bumps (electrodes) 120 having a plurality of protrusions are formed on the surfaces 110 a of the plurality of devices 110 formed on the surface 10 a of the semiconductor wafer 10. The protruding bumps (electrodes) 120 are formed to have a length of about 150 μm by the bump forming method described above, but the length varies.

  Further, as described above, the height of the surface 10a of the semiconductor wafer 10 on which the plurality of bumps (electrodes) 120 are formed is not necessarily uniform, and the center portion is high as shown exaggeratedly in FIG. It may be formed in a conical shape, or may be formed in a concave shape with a low center portion as shown exaggeratedly in FIG. As described above, the heights of the surfaces 110a of the plurality of devices 110 formed on the surface 10a of the semiconductor wafer 10 with the nonuniform height of the surface 10a are also nonuniform. Accordingly, the back surface of the semiconductor wafer 10 on which the plurality of devices 110 with the nonuniform height of the front surface 110a are formed is held on the holding surface 52a of the chuck table 52, and a plurality of the plurality of devices formed on the front surface 110a of the device 110 is formed. Even when the bumps (electrodes) 120 are turned by the turning unit 3 as the turning means, the lengths of the plurality of bumps (electrodes) 120 from the surface 110a of the device 110 vary.

  Therefore, when turning the plurality of bumps (electrodes) 120 formed on the surface of the semiconductor wafer 10 by the electrode processing apparatus described above, the height of the surface 110a of the plurality of devices 110 formed on the surface of the semiconductor wafer 10 is increased. The height is measured in advance by a height measuring device, and the X and Y coordinate values and the surface height (Z) of each device 110 are stored in a random access memory (RAM) 83 of the control means 8 as shown in FIG. .

  As described above, the first cassette 11 containing the semiconductor wafer 10 in which the heights of the surfaces 110 a of the plurality of devices 110 are measured is placed on the first cassette placement portion 11 a of the apparatus housing 2. When all the unprocessed semiconductor wafers 10 accommodated in the first cassette 11 placed on the first cassette placement portion 11a are carried out, a predetermined number of the wafers are replaced with the empty cassette 11. A new cassette 11 containing the unprocessed semiconductor wafer 10 is manually mounted on the first cassette mounting portion 11a. On the other hand, when a predetermined number of processed semiconductor wafers 10 are loaded into the second cassette 12 mounted on the second cassette mounting portion 12a of the apparatus housing 2, the second cassette 12 is manually unloaded. Then, a new empty second cassette 12 is placed.

Hereinafter, a turning process of aligning the lengths of the plurality of bumps (electrodes) 120 provided on the plurality of devices 110 formed on the surface of the semiconductor wafer 10 from the surface 110a of the device 110 using the above-described processing apparatus. Will be described.
The semiconductor wafer 10 as a workpiece before processing accommodated in the first cassette 11 is conveyed by the vertical movement and advancing / retreating operation of the workpiece conveying means 15 and placed on the workpiece temporary placing means 13. The semiconductor wafer 10 placed on the workpiece temporary placing means 13 is positioned in the workpiece loading / unloading area 24 by the turning operation of the workpiece loading means 16 after being centered here. It is placed on the chuck table 52 of the chuck table mechanism 5. The semiconductor wafer 10 placed on the chuck table 52 is sucked and held on the chuck table 52 by suction means (not shown).

  When the semiconductor wafer 10 is sucked and held on the chuck table 52, the processing feed means 56 (see FIG. 3) is operated to move the chuck table mechanism 5 in the direction indicated by the arrow X1, and as shown in FIG. The chuck table 52 holding 10 is positioned at the machining start position of the machining area 25. The rotary spindle 322 is driven to rotate from the state shown in FIG. 10, and the rotary substrate 33 to which the turning tool 34 is attached is rotated in the direction indicated by the arrow 33a in FIG. Then, the turning unit feed mechanism 4 is operated to position the turning unit 3 at a predetermined turning feed position. This turning feed position is set so that the tip of the turning tool 34 is positioned, for example, 100 μm above the surface 110 a of the device 110 provided on the surface 10 a of the semiconductor wafer 10. Next, the chuck table 52 holding the semiconductor wafer 10 is moved in the direction indicated by the arrow X1 in FIG. 10, that is, along the X coordinate axis at a feed rate of 1 mm / second, for example. As a result, a plurality of bumps (electrodes) 120 formed on the surface 110a of the device 110 provided on the surface 10a of the semiconductor wafer 10 by the cutting edge 342 of the turning tool 34 that rotates in accordance with the rotation of the rotary spindle 322 is a device. It is turned from the surface 110a of 110 at, for example, a position of 100 μm. Then, the center of the semiconductor wafer 10 held on the chuck table 52 moves to the center position of the cutting tool mounting substrate 33 as shown by a two-dot chain line in FIG. 10, whereby the device 110 provided on the surface 10 a of the semiconductor wafer 10. All of the plurality of bumps (electrodes) 120 formed on the surface 110a of the device 110 are turned, and the length from the surface 110a of the device 110 is made uniform.

In the above-described turning process, the chuck table 52 is moved in the Z-axis direction corresponding to the X and Y coordinate values of the plurality of devices 110 formed on the surface 10a of the semiconductor wafer 10 and the surface height (Z) of the devices 110. Displace to. Hereinafter, control for displacing the chuck table 52 in the Z-axis direction will be described. In order to carry out the control for displacing the chuck table 52 in the Z-axis direction, when the turning unit 3 is lowered and the turning tool 34 is positioned at a predetermined cutting position, it is arranged on the chuck table 52 and the movable base 51. A voltage of 5 V, for example, is applied to the plurality of piezo motors 53 disposed between the support member 510 and the cutting blade 342 of the turning tool 34 is set to the maximum value of the surface height (Z) of the plurality of devices. For example, it is positioned at a position 100 μm above the intermediate position (Z _min + (Z _max −Z _min ) / 2) between (Z _max ) and the minimum value (Z _min ). Then, when the rotating turning tool 34 passes through the X and Y coordinate values of each device, the control means 8 applies to the plurality of piezo motors 53 corresponding to the surface height (Z) of the X and Y coordinate values of the device. The voltage value to be controlled is controlled.

Here, with reference to FIG. 10, a method for detecting the time when the rotating turning tool 34 passes the X and Y coordinate values of each device 110 stored in the random access memory (RAM) 83 of the control means 8 will be described. I will explain.
If the turning radius of the cutting edge 342 of the turning tool 34 is (r) and the turning angle of the turning tool 34 from the X axis is (θ), the coordinate value of the turning position of the turning tool 34 with the rotation center as a fixed point is , X: r · cos θ, y: r · sin θ. When the distance between the rotation center of the turning tool 34 and the center of the chuck table 52, that is, the center (X: 0, Y: 0) of the semiconductor wafer 10 held by the chuck table 52 is (L), x: L + r · The coordinate values of cos θ, y: r · sin θ coincide with the X and Y coordinate values of each device 110 stored in the random access memory (RAM) 83 of the control means 8. Therefore, the control means 8 is based on the detection signals from the chuck table position detecting means 57 and the tool position detecting means 37, and the coordinate values (x: r · cos θ, y: r · sin θ) of the turning tool 34. And the devices formed in the X and Y coordinate values of each device stored in the random access memory (RAM) 83 of the control means 8 that coincides with the coordinate values of x: L + r · cos θ and y: r · sin θ Corresponding to the surface height (Z) of 110, a control signal is output to the voltage applying means 55 for applying a voltage to the plurality of piezo motors 53.

A voltage applied to the piezo motor 53 corresponding to the surface height (Z) of the device will be described.
In the illustrated embodiment, as described above, a voltage of 5 V is applied to the piezo motor 53 and the cutting edge 342 of the turning tool 34 has the maximum value (Z _max ) and the minimum value of the surface height (Z) of a plurality of devices. Since it is positioned at a position, for example, 100 μm above the intermediate position (Z _min + (Z _max −Z _min ) / 2) of (Z _min ), it is stored in the random access memory (RAM) 83 of the control means 8. When the surface height (Z) of the device at the X and Y coordinate values of the plurality of devices 110 is, for example, 1 μm lower than the intermediate position (Z _min + (Z _max −Z _min ) / 2), the control means 8 outputs a control signal to the voltage applying means 55 so as to apply a voltage of 7 V to the piezo motor 53. Further, the device surface height (Z) at the X and Y coordinate values of the plurality of devices 110 stored in the random access memory (RAM) 83 of the control means 8 is the intermediate position (Z _min + (Z _max − For example, when it is 0.5 μm higher than Z _min ) / 2), the control means 8 outputs a control signal to the voltage application means 55 so as to apply a voltage of 4 V to the piezo motor 53. In this way, it is applied to the piezo motor 53 corresponding to the surface height (Z) of the device at the X and Y coordinate values of the plurality of devices 110 stored in the random access memory (RAM) 83 of the control means 8. By controlling the voltage value, the chuck table 52 is displaced in the vertical direction (Z-axis direction) corresponding to the surface height (Z) of the device, and therefore, a plurality of bumps formed on the surface 110a of each device 110. The length of the (electrode) 120 from the surface 110a of the device 110 can be uniformly turned to 100 μm, for example.

  As described above, when the turning process of the plurality of bumps (electrodes) 120 formed on the surface of the device 110 provided on the semiconductor wafer 10 is completed, the turning unit 3 is raised. Next, the chuck table 52 is moved in the direction indicated by the arrow X2 in FIG. 1 to be positioned in the workpiece loading / unloading area 24, and the suction holding of the turned semiconductor wafer 10 on the chuck table 52 is released. Then, the semiconductor wafer 10 whose suction holding is released is carried out by the workpiece carrying-out means 17 and conveyed to the cleaning means 14. The semiconductor wafer 10 conveyed to the cleaning means 14 is cleaned here. The semiconductor wafer 10 cleaned by the cleaning unit 14 is stored in a predetermined position of the second cassette 12 by the workpiece transfer unit 15.

The perspective view of the electrode processing apparatus comprised according to this invention. Sectional drawing of the spindle unit which comprises the turning unit with which the electrode processing apparatus shown in FIG. 1 is equipped. The perspective view which shows the chuck table mechanism and chuck table moving mechanism with which the electrode processing apparatus shown in FIG. 1 is equipped. The principal part side view of the chuck table mechanism shown in FIG. FIG. 4 is a control map showing a relationship between a voltage value applied to a piezo motor constituting the chuck table mechanism shown in FIG. 3 and a displacement of the chuck table. The block diagram of the control means with which the electrode processing apparatus shown in FIG. 1 is equipped. 1 is a perspective view of a semiconductor wafer as a workpiece and a cross-sectional view showing an enlarged main part. Explanatory drawing which shows the example from which the height of the surface of the semiconductor wafer shown in FIG. 7 differs. FIG. 8 is an explanatory diagram showing X and Y coordinate values of each device formed on the semiconductor wafer shown in FIG. 7. Explanatory drawing of the turning process implemented using the electrode processing apparatus shown in FIG.

Explanation of symbols

2: Device housing 3: Grinding unit 31: Moving substrate 32: Spindle unit 321: Spindle housing 322: Rotary spindle 323: Tool mounting mount 33: Tool mounting substrate 34: Turning tool 36: Electric motor 37: Tool position detecting means 4: Turning unit feed mechanism 44: Pulse motor 5: Chuck table mechanism 51: Moving base 52: Chuck table 53: Piezo motor 55: Voltage application means 56: Work feed means 57: Chuck table position detection means 11: First cassette 12: Second cassette 13: Workpiece temporary placing means 14: Cleaning means 15: Workpiece conveying means 16: Workpiece carrying means 17: Workpiece carrying means 10: Semiconductor wafer 110: Semiconductor chip 111: Electrode plate 120 : Bump (electrode)

Claims (1)

A chuck table mechanism comprising a chuck table having a holding surface parallel to the X-axis direction and the Y-axis direction orthogonal to the X-axis direction, and a moving base for supporting the chuck table, and the holding surface of the chuck table Turning means for turning a plurality of protruding electrodes respectively provided on a plurality of devices formed on the surface of the wafer held by the wafer, and the turning base parallel to the holding surface of the chuck table In an electrode processing apparatus comprising a processing feed means for processing feed to the means,
The chuck table is supported via a piezo motor that is disposed between the moving base and is configured by a piezoelectric element that is displaced in a direction perpendicular to the holding surface.
The turning means includes a rotary spindle disposed in a direction perpendicular to the holding surface of the chuck table, a bite mounting substrate mounted on a lower end of the rotary spindle, and the bite mounting substrate decentered from an axis. A turning tool arranged in a position,
Chuck table position detecting means for detecting the movement position of the chuck table;
A tool position detecting means for detecting a rotational position of the cutting tool in the turning means;
Control means for controlling the piezo motor based on detection signals from the chuck table position detection means and the bite position detection means,
The control means includes a memory for storing the X and Y coordinate values of a plurality of devices formed on the surface of the wafer and the surface height positions of the devices detected in advance, and the turning tool is rotated by rotating the turning tool. X and Y coordinate values are obtained and applied to the piezo motor corresponding to the surface height position of the device at the X and Y coordinate values of the device when the turning tool passes through the X and Y coordinate values of each device. Control the voltage,
An electrode processing apparatus.

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