JP5424864B2 - Processing equipment - Google Patents

Description

  The present invention relates generally to a processing apparatus, and more particularly to a processing apparatus including a correction mechanism that corrects the tilt of a chuck table of a processing apparatus in accordance with a temperature change.

In a manufacturing process of a semiconductor device, an optical device, or the like, a plurality of elements are formed on a wafer using photolithography or the like. Thereafter, the wafer is ground to a predetermined thickness with a grinding machine, and if necessary, polished with a polishing machine to thin the wafer, and then divided into individual pieces with a cutting machine to produce various devices.

  On the other hand, in recent years, a technique called flip chip bonding has been put into practical use as a technique for realizing miniaturization and thinning of semiconductor devices. Flip chip bonding is a technique in which a plurality of metal projections called bumps are formed on the surface of a semiconductor device, and the bumps are directly bonded in correspondence with a plurality of electrodes formed on a wiring board.

  In order to uniformly bond a plurality of bumps to all the electrodes of the wiring board, it is necessary to make the heights of the bumps uniform. For example, Japanese Patent Application Laid-Open No. 2000-173955 discloses a device for aligning the heights of such bumps. A cutting tool is disclosed.

  In these processing apparatuses such as a grinding apparatus, a polishing apparatus, a cutting apparatus, and a cutting tool, a workpiece is held by a chuck table and a processing means such as a grinding wheel, a polishing pad, a cutting blade, and a cutting tool is used. Process the workpiece. Therefore, if the machining is performed in a state where the chuck table and the machining means are not parallel, the following various problems occur.

  For example, when the workpiece is cut in a state where the chuck table of the cutting device and the cutting blade are not parallel to form a plurality of cutting grooves, the formed cutting groove depths vary.

  Usually, in order to prevent the cutting blade from cutting into the chuck table and to facilitate the handling of the work piece separated after the cutting, the work piece is cut with a ring frame through a dicing tape. In this state, it is supported and sucked and held by the chuck table.

  However, if the cutting process is performed with the cutting blade and the chuck table not parallel, a part of the workpiece will not be cut into individual pieces or the dicing tape will be cut completely. There is a possibility that problems such as cutting of the cutting blade and damage of the chuck table may occur.

  On the other hand, when a grinding device, polishing device, tool cutting device, etc. performs processing such as grinding, polishing, tool cutting, etc. in a state where the processing means and the chuck table are not parallel, the work finish thickness of the workpiece Variation will occur.

  In particular, when bumps are flattened for flip chip bonding with a cutting tool, bump height varies if the chuck table and the cutting tool are not parallel, resulting in the formation of bumps and wiring boards. There is a risk of poor bonding with the electrode.

  Therefore, in these processing apparatuses, it is very important that the chuck table and the processing means are parallel, and the processing apparatus is assembled so that the processing means and the chuck table are parallel. For example, Japanese Patent Application Laid-Open No. 2002-1653 discloses a fine adjustment device that can adjust the inclination of a chuck table.

Japanese Patent Application Laid-Open No. 2000-173954 Japanese Patent Laid-Open No. 2002-1653

  However, in the fine adjustment device disclosed in Patent Document 2, the chuck table fine adjustment device itself is thermally expanded by the processing heat generated by the processing, and the chuck table is tilted during the processing, and the chuck table is tilted. There exists a problem that the to-be-processed workpiece will be inferior goods.

  The present invention has been made in view of these points, and an object of the present invention is to provide a machining apparatus capable of correcting the inclination of the chuck table in accordance with the machining heat generated by the machining.

  According to the present invention, there is provided a processing apparatus including a chuck table having a holding surface for holding a workpiece, and processing means for processing the workpiece held by the chuck table, the chuck table being fixed A fixed support portion that supports the chuck table, first and second movable support portions that are spaced apart from the fixed support portion in the circumferential direction and support the chuck table movably in the vertical direction, and the fixed First temperature rise measuring means for measuring the temperature rise value of the support part, second temperature rise measuring means for measuring the temperature rise value of the first movable support part, and measuring the temperature rise value of the second movable support part Third temperature rise measuring means, storage means for storing height position change data of the holding surface with respect to the temperature rise value, temperature rise values measured by the first to third temperature rise measuring means, The memory stored in the storage means And a control means for driving the first and second movable support portions based on the position change amount data to correct the inclination of the holding table in parallel with the processing means. Is provided.

  According to the present invention, the fixed holding portion and the first and second movable holding portions are each provided with temperature rise measuring means, and the first and second movable holding portions are based on the measured temperature rise value and height position change amount data. Since the inclination of the chuck table is corrected by driving the part, the chuck table and the processing means can always be kept parallel, so that no defective product is generated in the processed product.

It is a schematic block diagram of the grinding device which can apply the principle of this invention. It is a partially broken perspective view which shows the chuck table support structure of embodiment. It is a partially broken side view of the grinding apparatus shown in FIG. It is a schematic diagram which shows the support position of a flange.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a perspective view of a grinding apparatus 2 employing the chuck table support structure of the present invention. Reference numeral 4 denotes a base (housing) of the grinding apparatus 2, and two columns 6 a and 6 b are vertically provided behind the base 4. A pair of guide rails (only one is shown) 8 extending in the vertical direction is fixed to the column 6a.

  A rough grinding unit 10 is mounted along the pair of guide rails 8 so as to be movable in the vertical direction. The rough grinding unit 10 is attached to a moving base 12 whose housing 20 moves up and down along a pair of guide rails 8.

  The rough grinding unit 10 includes a housing 20, a spindle (not shown) rotatably accommodated in the housing 20, a servo motor 22 that rotationally drives the spindle, and a plurality of rough grinding grinding wheels fixed to the tip of the spindle. A grinding wheel 24 having 26 is included.

  The rough grinding unit 10 includes a rough grinding unit moving mechanism 18 including a ball screw 14 and a pulse motor 16 that move the rough grinding unit 10 up and down along a pair of guide rails 8. When the pulse motor 16 is pulse-driven, the ball screw 14 rotates and the moving base 12 is moved in the vertical direction.

  A pair of guide rails (only one is shown) 19 extending in the vertical direction is also fixed to the other column 6b. A finish grinding unit 28 is mounted along the pair of guide rails 19 so as to be movable in the vertical direction.

  The finish grinding unit 28 is attached to a moving base (not shown) in which the housing 36 moves in the vertical direction along the pair of guide rails 19. The finish grinding unit 28 includes a housing 36, a spindle (not shown) rotatably accommodated in the housing 36, a servo motor 38 that rotationally drives the spindle, and a grinding wheel 42 for finish grinding fixed to the tip of the spindle. A grinding wheel 40 is included.

  The finish grinding unit 28 includes a finish grinding unit moving mechanism 34 including a ball screw 30 and a pulse motor 32 that move the finish grinding unit 28 in the vertical direction along the pair of guide rails 19. When the pulse motor 32 is driven, the ball screw 30 rotates and the finish grinding unit 28 is moved in the vertical direction.

  The grinding apparatus 2 includes a turntable 44 disposed on the front side of the columns 6a and 6b. The turntable 44 is formed in a relatively large-diameter disk shape, and is rotated in a direction indicated by an arrow 45 by a rotation drive mechanism (not shown).

  On the turntable 44, three chuck tables 46 are arranged so as to be rotatable in a horizontal plane, spaced from each other by 120 ° in the circumferential direction. The chuck table 46 has a suction chuck formed in a disk shape by a porous ceramic material, and sucks and holds the wafer placed on the holding surface of the suction chuck by operating a vacuum suction means. A thickness gauge 48 measures the thickness of the wafer being ground.

  The three chuck tables 46 arranged on the turntable 44 are rotated in accordance with the turntable 44, so that the wafer loading / unloading area A, rough grinding area B, finish grinding area C, and wafer loading / unloading are performed. The region A is sequentially moved.

  In the front portion of the base 4, there are a first wafer cassette 50, a second wafer cassette 52, a wafer transfer robot 54, a positioning table 56 having a plurality of positioning pins 58, and a wafer carry-in mechanism (loading arm) 60. A wafer unloading mechanism (unloading arm) 62 and a spinner unit 63 are disposed.

  A cleaning water spray nozzle 67 for cleaning the chuck table 46 is provided at the approximate center of the base 4. The cleaning water spray nozzle 67 sprays cleaning water toward the chuck table 46 in a state where the chuck table 46 is positioned in the wafer carry-in / carry-out region A.

  Referring to FIG. 2, a partially broken perspective view of the support structure for the chuck table 46 according to the embodiment is shown. FIG. 3 is a partially broken side view of the grinding apparatus shown in FIG. As shown in FIG. 2, the chuck table 46 includes a suction chuck 68 formed in a disk shape from a porous ceramic material, and a metal frame 70 surrounding the suction chuck. An annular flange 72 is formed integrally with the frame body 70. The chuck table 46 is connected to a motor 74 and is driven to rotate by the motor 74.

  As shown in FIG. 3, the turntable 44 includes a turntable base 44a and a turntable cover 44b, and the chuck table 46 projects upward from an opening 47 formed in the turntable cover 44b.

  The annular flange 72 is formed with three through holes that are 120 degrees apart from each other in the circumferential direction. A bolt 76 is inserted into one through hole formed in the flange 72, and the tip of the bolt 76 is engaged with an engaged member 78 fixed to the turntable base 44a. The bolt 76 and the engaged member 78 constitute a fixed support portion 80.

  A bolt 82 constituting the movable support portion 90 is inserted into another through hole formed in the annular flange 72, and a tip end portion of the bolt 82 is inserted into a through hole 83 formed in the turntable base 44a. Is engaged with one end of the. The rod 84 has a screw hole, and a screw 88 connected to the output shaft of the pulse motor 86 is screwed into the screw hole.

  The pulse motor 86 is fixed to the turntable base 44a by a bracket (not shown). When the pulse motor 86 is driven, the screw 88 is rotated and the bolt 82 constituting the movable support portion 90 is moved in the vertical direction. A movable support portion having the same configuration as that of the movable support portion 90 is disposed in another through hole portion of the annular flange 72.

  Referring to FIG. 3, the turntable base 44 a of the turntable 44 is mounted on the motor 92 and is rotated by the motor 92. The suction chuck 68 of the chuck table 46 is connected to a negative pressure source via a tube 94, and a suction force is applied to the suction chuck 68 by the negative pressure source.

  A temperature rise measuring means 96 such as a radiation thermometer for measuring the amount of infrared rays is disposed adjacent to the fixed support portion 80. Similarly, a temperature rise measuring means 98 such as a radiation thermometer for measuring the amount of infrared rays is disposed adjacent to the movable support portion 90. Similar temperature rise measuring means are arranged for the other movable support portions.

  Instead of a non-contact thermometer such as a radiation thermometer, a contact-type thermometer such as a thermocouple thermometer or a thermistor may be attached to members constituting the fixed support portion 80 and the movable support portion 90 as a temperature rise measuring means. Good.

  The temperature rise measuring means 96 and 98 are connected to the control means 100. A pulse motor 86 constituting the movable support portion 90 is also connected to the control means 100. The memory 102 stores height position change amount data of the suction chuck 68 of the chuck table 46 with respect to the temperature rise values measured by the temperature rise measuring means 96 and 98.

  Next, the effect | action of this invention is demonstrated based on the schematic diagram of FIG. The annular flange 72 of the chuck table 46 is supported at three points A, B, and C that are 120 degrees apart from each other in the circumferential direction, and A is a fixed support portion, and B and C are movable support portions.

  When the wafer held by the chuck table 46 is ground by the rough grinding unit 10 or the finish grinding unit 28, processing heat is generated and the temperature of the chuck table 46 rises. The temperature change of the chuck table 46 is measured by temperature rise measuring means 96 and 98 disposed on the fixed support portion 80 and the two movable support portions 90.

  From the measured temperature rise value, the height position change amount data stored in the memory 102 is searched, and the height position change amount is +2 μm at the point A which is the fixed support part, and +3 μm at the point B of the movable support part. If the C point of the movable support portion is +5 μm, the pulse motor 86 is driven to move the B point by −1 μm (+ 2-3) and the C point by −3 μm (+ 2-5), thereby the chuck table. The suction surface of the suction chuck 68 can be kept horizontal by correcting the inclination of 46.

  According to the embodiment described above, the temperature rise value of the fixed support portion 80 and the temperature rise value of the movable support portion 90 are measured by the temperature rise measuring means 96 and 98, respectively, and the temperature rise value generated by the processing heat is calculated. Based on the temperature rise value, the temperature rise value and height position change data stored in advance in the memory 102 are searched to obtain the height position change.

  Based on the amount of change, the pulse motor 86 is pulse-driven to correct the height of the movable support portion 90. Thereby, the fluctuation | variation of the height position of the chuck table 46 resulting from processing heat is correct | amended, and the adsorption | suction surface of the adsorption | suction chuck | zipper 68 can always be hold | maintained horizontally.

  In the above-described embodiment, the example in which the present invention is applied to the grinding apparatus has been described. However, the present invention can be similarly applied to other processing apparatuses such as a cutting apparatus, a polishing apparatus, and a cutting tool using a chuck table. is there.

2 Grinding device 10 Rough grinding unit 28 Finish grinding unit 44 Turntable 44a Turntable base 44b Turntable cover 46 Chuck table 68 Suction chuck 80 Fixed support 84 Rod 86 Pulse motor 88 Screw 90 Movable support 96, 98 Temperature rise measurement means

Claims (1)

A processing apparatus comprising: a chuck table having a holding surface for holding a workpiece; and processing means for processing the workpiece held by the chuck table,
A fixed support portion for fixedly supporting the chuck table;
First and second movable support portions that are spaced apart from the fixed support portion in the circumferential direction and support the chuck table movably in the vertical direction;
First temperature rise measuring means for measuring a temperature rise value of the fixed support portion;
Second temperature rise measuring means for measuring a temperature rise value of the first movable support portion;
Third temperature rise measuring means for measuring a temperature rise value of the second movable support portion;
Storage means for storing height position change amount data of the holding surface with respect to a temperature rise value;
Driving the first and second movable support portions based on the temperature rise value measured by the first to third temperature rise measuring means and the height position change amount data stored in the storage means; Control means for correcting the inclination of the holding table in parallel with the processing means;
A processing apparatus comprising:

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