JP5645692B2 - Processing method - Google Patents

Description

  The present invention relates to a processing method for processing a workpiece with a processing apparatus including two processing means.

  In the manufacturing process of a semiconductor device, a plurality of semiconductor chips on which circuits such as LSI are formed are mounted on a lead frame or a printed circuit board, and each electrode is bonded and then sealed with a resin, so that CSP (Chip) A package substrate such as a size package substrate or a BGA (Ball Grid Array) substrate is formed.

  Thereafter, the package substrate is diced with a cutting blade of a cutting device and separated into individual pieces, whereby individual semiconductor packages sealed with resin are manufactured. The semiconductor package manufactured in this way is widely used for electric devices such as mobile phones and personal computers.

  In the above-described CSP substrate, package substrate such as a BGA substrate, ceramic substrate such as a piezoelectric element, or resin substrate, the workpiece itself is distorted, and the planned cutting lines formed on the surface are not necessarily parallel to each other.

  Japanese Patent Laid-Open No. 9-52227 proposes a method for cutting a ceramic substrate having a plurality of cutting lines that are not necessarily parallel. In the cutting method proposed in this publication, the alignment process is performed on all the planned cutting lines, and the alignment information is stored in the memory of the controller. At the time of cutting, the alignment information stored in the memory is called to perform cutting. I am carrying out.

JP 2001-298002 A Japanese Patent Laid-Open No. 9-52227

  However, in the case of dual cutting using a dual dicer having two spindles, since two axes are cut simultaneously, when cutting a workpiece whose cutting lines are not parallel to each other, cutting is planned on either axis. There is a problem that cutting along the line is not possible. On the other hand, when cutting with only one axis, the throughput is lower than that of dual cutting, and there is no advantage of using a dual dicer.

  The present invention has been made in view of these points, and an object of the present invention is to provide a cutting method capable of cutting a workpiece with high accuracy without damaging the chip and not reducing the throughput. It is.

  According to the present invention, the holding table that rotatably holds the workpiece, the first and second processing means that process the workpiece held by the holding table, the first and second processing means, and the A machining feed means for relatively moving the holding table in the X-axis direction, a first indexing means for relatively moving the first machining means and the holding table in the Y-axis direction orthogonal to the X-axis direction, and the Y-axis A processing apparatus having a second indexing and feeding means for relatively moving the second processing means and the holding table in a direction, and a workpiece having a plurality of processing lines not parallel to each other along the processing lines. A holding step for holding a workpiece on the holding table, and a first scheduled machining line among a plurality of scheduled machining lines by rotating the holding table holding the workpiece. X direction A positioning step that is positioned in parallel with the workpiece, and after the positioning step is performed, the first indexing means is used to index and feed the first processing means to the first scheduled processing line, and the workpiece feeding means is further used to process the workpiece. A forward machining step for machining the workpiece from one end to the other end by the first machining means while machining the workpiece in the first machining feed direction, and after performing the forward machining step, the forward machining step In order to position the second scheduled machining line different from the first scheduled machining line machined in step 1 in parallel with the X-axis direction, the holding table is slightly rotated to move the second scheduled machining line to the X-axis. After performing the angle fine adjustment step positioned parallel to the axial direction, and the angle fine adjustment step, the second indexing means indexes the second processing means to the second scheduled processing line. Furthermore, the workpiece is fed from the other end to the one end by the second machining means while the workpiece is fed in the second machining feed direction opposite to the first machining feed direction by the machining feed means. There is provided a machining method characterized by comprising a backward machining step for machining the backward path toward the surface.

  Preferably, the first processing means and the second processing means are arranged to face each other in alignment in the Y-axis direction, the first processing means includes a first cutting blade, and the second processing means Includes a second cutting blade, and both the first cutting blade and the second cutting blade rotate in a cutting direction from the upper side to the lower side of the workpiece during cutting.

  According to the present invention, there is provided a machining method that can accurately cut a workpiece whose cutting lines are not parallel to each other without damaging the chip, and that does not reduce the throughput of the machining apparatus having the first and second machining means. can do.

It is a perspective view of the cutting device suitable for implementing the processing method of this invention. It is a disassembled perspective view which shows the relationship between a spindle and the blade mount which should be fixed to a spindle. It is a disassembled perspective view which shows the relationship between a blade mount and the cutting blade which should be mounted | worn with a blade mount. It is a top view of the package board | substrate with which the fixing jig was mounted | worn. It is a flowchart which shows the processing method of embodiment of this invention. 6 is a flowchart showing a continuation of FIG. It is a top view which shows a holding | maintenance step. It is a top view explaining a positioning step. It is a top view which shows an outward process step. It is a top view explaining an angle fine adjustment step. It is a top view which shows a homeward process step. It is a top view which shows the relationship between a parallel dual dicer and the package board | substrate with which the fixing jig was mounted | worn.

  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 cutting device (dicing device) 2 suitable for carrying out the package substrate cutting method of the present invention.

  The cutting device 2 is a two-spindle type cutting device that sucks and holds a workpiece on the holding table 4, and the holding table 4 reciprocates in the cutting feed direction (X-axis direction) while indexing feed direction (Y-axis direction). And the work of the first cutting means 6 and the second cutting means 8 moving in the cutting feed direction (Z-axis direction).

  For example, when cutting the package substrate 21, as shown in FIG. 1, the holding jig 4 having a plurality of relief grooves corresponding to a plurality of cutting lines of the package substrate 21 is sucked and held by the holding table 4. The substrate 21 is mounted on the fixing jig 86 and fixed.

  The holding table 4 can be moved in the X-axis direction by the cutting feed means 10, and the first alignment means 12 having a first camera (first imaging means) 13 formed integrally with the first cutting means 6. In the region to be cut of the package substrate 21 sucked and held by the holding table 4 by the second alignment means 14 having the second camera (second imaging means) 15 formed integrally with the second cutting means 8. A certain street (scheduled cutting line) is detected, and after the street and the cutting blade are aligned in the Y-axis direction, cutting is performed.

  The cutting feed means 10 includes a pair of X-axis guide rails 16 disposed in the X-axis direction, an X-axis movement base 18 slidably supported by the X-axis guide rails 16, and an X-axis movement base 18. An X-axis ball screw 20 that is screwed into a nut portion (not shown) formed on the X-axis and an X-axis pulse motor 22 that rotationally drives the X-axis ball screw 20.

  The support base 24 that instructs the holding table 4 to be rotatable is fixed to the X-axis moving base 18, and is driven by the X-axis pulse motor 22 to rotate the X-axis ball screw 20. It is moved in the X-axis direction.

  On the other hand, the first cutting means 12 and the second cutting means 14 are supported by the guide means 26 so as to be indexable in the Y-axis direction. The guide means 26 includes a vertical column 28 disposed in the Y-axis direction orthogonal to the X-axis so as not to prevent the movement of the holding table 4, and a pair of Y disposed in the Y-axis direction on the side surface of the vertical column 28. A shaft guide rail 30, a first ball screw 32 and a second ball screw 34 arranged in parallel with the Y axis guide rail 30, and a first Y axis pulse motor connected to the first ball screw 32. 36 and a second Y-axis pulse motor 38 connected to the second ball screw 34.

  The Y-axis guide rail 30 supports the first support member 40 and the second support member 42 so as to be slidable in the Y-axis direction, and is provided in the first support member 40 and the second support member 42. Nuts (not shown) are screwed into the first ball screw 32 and the second ball screw 34, respectively.

  Driven by the first Y-axis pulse motor 36 and the second Y-axis pulse motor 38 and the first ball screw 32 and the second ball screw 34 rotate, respectively, the first support member 40 and the second The support members 42 are independently moved in the Y-axis direction.

  The positions of the first support member 40 and the second support member 42 in the Y-axis direction are measured by the linear scale 44 and used for precise control of the Y-axis direction positions. Although it is possible to provide a linear scale separately for each support member, it is better to measure the positions of both the first support member 40 and the second support member 42 with a single linear scale 44. It is possible to precisely control the distance between.

  A first moving member 46 to which the first cutting means 6 is attached is attached to the first support member 40 so as to be slidable in the vertical direction (Z-axis direction). The first Z-axis pulse motor When 48 is driven, the first moving member 46 is moved in the Z-axis direction.

  Similarly, a second moving member 50 to which the second cutting means 8 is attached is attached to the second support member 42 so as to be slidable in the vertical direction (Z-axis direction). By driving the shaft pulse motor 52, the second moving member 50 is moved in the Z-axis direction.

  Next, with reference to FIG.2 and FIG.3, the structure of the 1st cutting means 6 is demonstrated. Referring to FIG. 2, an exploded perspective view showing the relationship between the spindle 56 and the blade mount 60 attached to the spindle 56 is shown.

  A spindle 56 that is rotationally driven by a servo motor (not shown) is rotatably accommodated in the spindle housing 54 of the first cutting means 6. The spindle 56 has a tapered portion 56a and a small distal end portion 56b, and a male screw 58 is formed on the small distal end portion 56b.

  Reference numeral 60 denotes a blade mount including a boss part (convex part) 62 and a fixing flange 64 formed integrally with the boss part 62, and a male screw 66 is formed on the boss part 62. Further, the blade mount 60 has a mounting hole 67.

  In the blade mount 60, the mounting hole 67 is inserted into the small diameter portion 56b and the tapered portion 56a of the spindle 56, and the nut 68 is screwed into the male screw 58 to be tightened, so that the distal end portion of the spindle 56 is shown in FIG. Attached to.

  FIG. 3 is an exploded perspective view showing a mounting relationship between the spindle 56 to which the blade mount 60 is fixed and the first cutting blade 70. The first cutting blade 70 is called a washer blade, and is composed of an electroformed cutting blade (electroforming grindstone).

  The first cutting blade 70 is inserted into the boss portion 62 of the blade mount 60, the detachable flange 72 is further inserted into the boss portion 62, and the fixing nut 74 is screwed into the male screw 66 and tightened. Is fixed to the spindle 26 by being sandwiched from both sides by a fixing flange 64 and a detachable flange 74.

  The second cutting means 8 is configured in substantially the same manner as the first cutting means 6 described above, and description thereof is omitted to avoid duplication. Referring to FIG. 7, reference numeral 82 denotes a spindle of the second cutting means 8, and a second cutting blade 84 is attached to the tip portion thereof.

  When a new first cutting blade 70 is mounted on the blade mount 60 fixed to the spindle 56, the operation of aligning the reference line of the first imaging means (first camera) 13 and the center line of the first cutting blade 70 in advance (hairline) ).

  Specifically, this hairline alignment operation is performed by once processing a groove on the surface of the workpiece with the first cutting blade 70 and imaging the processed groove with the first imaging means 13. The center of the machining groove is detected, the amount of deviation between the center position of the groove and the reference line position of the first image pickup means 13 is calculated, and the amount of deviation is added to or subtracted from the coordinate position. This is done by causing the cutting device 2 to store the origin position that matches the reference line position of the image pickup means 13. The hairline matching operation of the second cutting blade 84 attached to the second cutting means 8 is performed in the same manner.

  Referring to FIG. 4, a plan view of the package substrate 21 that is a processing target mounted on the fixing jig 86 shown in FIG. 1 is shown. The package substrate 21 has, for example, a rectangular metal frame 23. In the example shown in the figure, there are three device regions 27a and 27b in the region surrounded by the outer peripheral surplus region 25 and the non-device region 25a. , 27c.

  A plurality of alignment marks 29a are formed in the vicinity of the left end 21a of the package substrate 21, and a plurality of alignment marks 29b are formed in the vicinity of the right end 21b. Similarly, a plurality of alignment marks 29c are formed in the vicinity of the lower end 21c of the package substrate 21, and a plurality of alignment marks 29d are formed in the vicinity of the upper end 21d.

  Each device region 27a, 27b, 27c is partitioned by a plurality of first cutting scheduled lines 31a connecting the alignment marks 29a and 29b and a plurality of second cutting scheduled lines 31b connecting the alignment marks 29c and 29d. A device forming portion 33 is defined, and a plurality of electrodes (not shown) are formed in each device forming portion 33.

  The electrodes formed on the device forming portion 33 are insulated from each other by a resin molded on the metal frame 23. By cutting the first scheduled cutting line 31a and the second scheduled cutting line 31b, the electrodes of each device appear on both sides thereof.

  Although not particularly illustrated, devices are formed on the back surfaces of the device forming portions 33 in the device regions 27a, 27b, and 27c, and the back surfaces of the device regions 27a, 27b, and 27c are sealed with resin.

  Next, the cutting method of the embodiment of the present invention will be described in detail with reference to the flowcharts shown in FIGS. 5 and 6 and FIGS. 7 to 12. First, in step S10 of the flowchart shown in FIG. 5, the alignment marks 29a, 29b, 29c, and 29d of the package substrate 21 are registered in the memory of the cutting apparatus.

  As a result, the controller of the cutting apparatus recognizes the plurality of first scheduled cutting lines 31a connecting the corresponding alignment marks 29a and 29b and the plurality of second scheduled cutting lines 31b connecting the corresponding alignment marks 29c and 29d. can do.

  Next, the process proceeds to step S11, and the package substrate 21 is held by the holding table 4 via the fixing jig 86 as shown in FIG. Next, the process proceeds to step S12, and the first cutting scheduled line 31a of A1 is positioned parallel to the X-axis direction based on the alignment marks 29a and 29b of A1.

  That is, as shown in FIG. 8, the holding table 4 that sucks and holds the package substrate 21 via the fixing jig 86 is slightly rotated in the direction of arrow A, so that the first cutting scheduled line 13a of A1 becomes the X-axis direction. Position in parallel.

  Next, the process proceeds to step S13, where the cutting position and the angle of the holding table 4 are set for each of the first scheduled cutting lines 31a based on the left and right alignment marks 29a, 29b. The angle of the holding table 4 at the time of cutting is memorize | stored.

  Next, after rotating the holding table 4 by 90 degrees, the cutting position and the angle of the holding table 4 are set for each of the second scheduled cutting lines 31b based on the alignment marks 29c and 29d. The cutting position and the angle of the holding table 4 at the time of cutting are stored (alignment step).

  As described above, the alignment may be performed for all the first scheduled cutting lines 31a and all the second scheduled cutting lines 31b. In the processing region 27a, for example, alignment is performed for A1 and A6, and the central portions A2 to A2 are performed. The cutting position and angle of A5 may be calculated by dividing the difference between the coordinate position and angle of A1 and A6 into five equal parts. Further, when there are three or more alignment patterns on the same scheduled cutting line, the scheduled cutting line may be set by an approximate straight line by the least square method.

  Next, the process proceeds to step S14, where the first cutting blade 70 is positioned at one end 21a of the first cutting planned line 31a of A1, and the package substrate 21 is cut along the first cutting planned line 31a from one end 21a to the other end 21b. To do.

  That is, as shown in FIG. 9, the first cutting blade 70 that rotates in the R1 direction is positioned at a predetermined height, and the first Y-axis pulse motor 36 is driven to move the first cutting blade 70 to the first cutting of A1. After indexing and feeding to the planned line 31a, the holding table 4 is moved in the direction of the arrow X1 while the cutting blade 70 is rotated at a high speed and the package substrate 21 is cut down from the upper side to the lower side. Cutting is performed from 21a to the other end 21b along the first scheduled cutting line 31a to form a cutting groove 35 as shown in FIG. After the end of cutting, the first cutting blade 70 is raised to a height at which the package substrate 21 is not cut.

  Next, the process proceeds to step S15, and as shown in FIG. 10, the holding table 4 is slightly rotated in the direction of arrow B to position the first cutting planned line 31a of A18 parallel to the X-axis direction (angle fine adjustment step). .

  Subsequently, it progresses to step S16, and after positioning the 2nd cutting blade 84 in the 1st cutting plan line 31a of A18, the package board | substrate 21 is cut from the other end 21b to the one end 21a.

  That is, as shown in FIG. 11, the second cutting blade 84 rotating in the direction of the arrow R2 is positioned at a predetermined height, and the second Y-axis pulse motor 84 is driven to move the second cutting blade 84 to the first of A18. After indexing and feeding to the scheduled cutting line 31a, the second cutting blade 84 is cut from the upper side to the lower side of the package substrate 21 while rotating at a high speed, and the holding table 4 is moved in the direction of the arrow X2 to thereby move the package substrate 21. Is cut from the other end 21b to the one end 21a along the first scheduled cutting line 31a. After the end of cutting, the second cutting blade 84 is raised to a height at which the package substrate 21 is not cut.

  Next, the first scheduled cutting line 31a to be cut is changed, and the cutting of all the first scheduled cutting lines 31a is completed in the forward machining step in step S14, the fine angle adjustment step in step S15, and the backward machining step in step S16. Repeat until.

  Next, the process proceeds to step S17, and after cutting all the first scheduled cutting lines 31a, the holding table 4 is rotated by 90 degrees to position the second scheduled cutting line 31b of B1 parallel to the X-axis direction.

  Next, the process proceeds to step S18, and similarly to step S14, the first cutting blade 70 is positioned on the second planned cutting line 31b of B1, and the package substrate 21 is moved from the one end 21c to the other end 21d on the second planned cutting line 31b. Cut along.

  Next, the process proceeds to step S19, and similarly to step S15, the holding table 4 is slightly rotated to position the second scheduled cutting line 31b of B6 parallel to the X-axis direction (angle fine adjustment step).

  After the fine angle adjustment step, the process proceeds to step S20, and similarly to step S16, the second cutting blade 84 is positioned on the second planned cutting line 31b of B6, and the package substrate 21 is moved from the other end 21d to the one end 21c. 2 Cut along the planned cutting line 31b.

  Next, the second cutting scheduled line 31b to be cut is changed, the forward machining step in step S18, the fine angle adjustment step in step S19, and the backward machining step in step S20 are completed. Repeat until

  In the above-described embodiment, the example in which the package substrate 21 is cut by the facing dual dicer in which the first cutting blade 70 and the second cutting blade 84 face each other has been described. However, the cutting device is not limited to this type. As shown in FIG. 12, the first cutting means 6A and the second cutting means 8A may perform cutting with parallel parallel dicers.

  In the present embodiment described above, it is possible to cut a workpiece such as the package substrate 21 whose cutting lines are not parallel with high accuracy without damaging the chip. Further, at the end of cutting with the first cutting blade 70, the cutting is performed with the second cutting blade 84 while returning the holding table 4, so that the package substrate 21 can be cut without reducing the throughput of the dual dicer. .

  In the above-described embodiment, the processing method of the present invention has been described with respect to the cutting method using a dual dicer. However, the processing method of the present invention is not limited to this, and processing by a laser processing apparatus having two laser beam irradiation units. Can be provided as well.

4 Holding table 6 First cutting means 8 Second cutting means 21 Package substrate 21a, 21c One end 21b, 21d Other end 27a, 27b, 27c Device region 29a, 29b, 29c, 29d Alignment mark 31a First scheduled cutting line 31b Second Planned cutting line 33 Device forming portion 35 Cutting groove 70 First cutting blade 84 Second cutting blade 86 Fixing jig

Claims (2)

A holding table for rotatably holding a workpiece, first and second processing means for processing the workpiece held by the holding table, the first and second processing means, and the holding table are X A machining feed means for relatively moving in the axial direction; a first indexing means for relatively moving the first machining means and the holding table in the Y-axis direction orthogonal to the X-axis direction; and the second in the Y-axis direction. A processing method for processing a workpiece having a plurality of processing lines that are not parallel to each other along the processing line, in a processing apparatus that includes a processing unit and a second index feed unit that relatively moves the holding table. Because
A holding step for holding the workpiece on the holding table;
A positioning step of rotating the holding table holding the workpiece to position the first scheduled machining line among the plurality of scheduled machining lines in parallel with the X-axis direction;
After performing the positioning step, the first indexing means causes the first processing means to be indexed and fed to the first scheduled processing line, and the work feeding means further moves the workpiece in the first machining feed direction. An outward machining step of machining the workpiece from one end to the other end with the first machining means while machining and feeding;
After carrying out the forward machining step, the holding table is slightly moved in order to position a second machining scheduled line different from the first machining scheduled line machined in the outgoing machining step in parallel with the X-axis direction. An angle fine adjustment step of rotating and positioning the second processing line to be parallel to the X-axis direction;
After performing the angle fine adjustment step, the second indexing means causes the second machining means to index and feed the second machining scheduled line, and the machining feed means further processes the workpiece to the first machining. A backward machining step in which the workpiece is fed backward from the other end toward the one end by the second machining means while being fed in a second machining feed direction opposite to the feed direction;
The processing method characterized by comprising. The first processing means and the second processing means are arranged to face each other in alignment in the Y-axis direction,
The first processing means includes a first cutting blade, and the second processing means includes a second cutting blade,
The cutting method according to claim 1, wherein both the first cutting blade and the second cutting blade rotate in a direction of cutting from the upper side to the lower side of the workpiece during cutting.

Images