Processing method for resin substrates

Abstract

To provide a resin substrate processing method in which a convex portion on the outer periphery does not interfere when dividing the resin substrate into individual chips.SOLUTION: A resin substrate processing method includes a holding step of holding a resin substrate 20 on a chuck table 10a, a protrusion flattening step of positioning a cutting blade 83 on the outer periphery 22 of the resin substrate 20 and cutting protrusions 23a to 23d to have approximately the same height as a central flat portion 21, and a dividing step of dividing the resin substrate 20 into individual chips 24 by operating X-axis feeding means and Y-axis feeding means.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a processing method for dividing a resin substrate into individual chips.

Background Art

[0002] A wafer on which a plurality of devices such as ICs and LSIs are partitioned by a dicing line and formed on the surface is divided into individual device chips by a dicing device and used in electric devices such as mobile phones and personal computers.

[0003] Also, a technique has been proposed for dividing a resin substrate sealed with a resin such as glass epoxy resin into individual chips after a plurality of devices on which circuits such as LSIs are formed are mounted on a lead frame and bonded (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, depending on the type or configuration of the resin substrate, resin may accumulate on the outer periphery of the resin substrate in the process of coating the substrate on which a plurality of devices are formed with resin, and a convex portion like an embankment may be formed so as to surround the flat portion at the center of the completed resin substrate, and there is a problem that it becomes an obstacle when cutting the resin substrate into individual chips.

[0006] The present invention has been made in view of the above facts, and its main technical problem is to provide a processing method for a resin substrate in which the above-described convex portion on the outer periphery does not become an obstacle when dividing the resin substrate into individual chips.

Means for Solving the Problems

[0007] To solve the above-mentioned main technical problems, the present invention provides a chuck table that can hold and rotate a workpiece, a cutting means that supports a cutting blade for cutting the workpiece held on the chuck table on a rotating shaft extending in the Y-axis direction, an X-axis feed means that feeds the chuck table and the cutting means relatively in the X-axis direction, a Y-axis feed means that feeds the chuck table and the cutting means relatively in the Y-axis direction which is perpendicular to the X-axis direction, and a means that feeds the chuck table and the cutting means relatively perpendicular to the X-axis and Y-axis directions. A method for processing a resin substrate is provided, comprising a cutting device equipped with a Z-axis feed means for cutting and feeding in the Z-axis direction, wherein the resin substrate having a convex portion on the outer circumference of a central flat portion is divided into individual chips, the method comprising: a holding step of holding the resin substrate on a chuck table; a convex portion flattening step of positioning the cutting blade on the outer circumference of the resin substrate and cutting the convex portion to bring it to approximately the same height as the central flat portion; and a dividing step of operating the X-axis feed means and Y-axis feed means to divide the resin substrate into individual chips.

[0008] The process includes an integration step in which a resin substrate is positioned in the opening of a frame having an opening in the center and integrated with a sheet, and in the holding step, it is preferable to hold the sheet side on a chuck table. The resin substrate is rectangular, and the protrusion flattening step includes a positioning step in which one side of the resin substrate having a protrusion is positioned in the Y-axis direction, a flattening step in which the tip of a cutting blade is positioned on the protrusion of the resin substrate and the protrusion is flattened by relative movement in the Y-axis direction, an indexing step in which the tip of the cutting blade and the protrusion of the resin substrate are relatively indexed in the X-axis direction according to the width of the protrusion, and a cutting step in which the tip of the cutting blade and the protrusion of the resin substrate are relatively cut in the Z-axis direction according to the height of the protrusion, and the flattening step, the indexing step and the cutting step may be repeated as needed. [Effects of the Invention]

[0009] The present invention provides a cutting device comprising: a chuck table that holds and rotates a workpiece; a cutting means for which a cutting blade for cutting the workpiece held on the chuck table is supported on a rotating shaft extending in the Y-axis direction; an X-axis feed means for feeding the chuck table and the cutting means relative to each other in the X-axis direction; a Y-axis feed means for feeding the chuck table and the cutting means relative to each other in the Y-axis direction perpendicular to the X-axis direction; and a Z-axis feed means for cutting the chuck table and the cutting means relative to each other in the Z-axis direction perpendicular to both the X-axis and Y-axis directions, thereby producing a workpiece with a protrusion on the outer circumference of the central flat portion. A method for processing a resin substrate to divide it into individual chips, comprising: a holding step of holding the resin substrate on a chuck table; a protrusion flattening step of positioning the cutting blade on the outer circumference of the resin substrate and cutting the protrusions to bring them to approximately the same height as the central flat portion; and a dividing step of operating the X-axis feed means and Y-axis feed means to divide the resin substrate into individual chips. As a result, when the dividing step of dividing the resin substrate into individual chips is performed, the protrusions resembling ridges are removed from the outer circumference of the resin substrate and it is made approximately flat, thus eliminating the problem that these protrusions would hinder the division of the resin substrate into individual chips. [Brief explanation of the drawing]

[0010] [Figure 1] This is an overall perspective view of the cutting machine. [Figure 2] This is a perspective view showing an embodiment of the integrated process. [Figure 3] (a) A perspective view showing an embodiment of the convex flattening process, and (b) A partially enlarged cross-sectional view of the convex flattening process shown in (a). [Figure 4] (a) A perspective view showing a resin substrate that has been flattened by the convex portion flattening process, and (b) A side view of the resin substrate shown in (a) as seen from the side. [Figure 5] (a) A perspective view showing an embodiment of the splitting process, and (b) A perspective view showing the resin substrate divided into individual chips by the splitting process shown in (a). [Modes for carrying out the invention]

[0011] Hereinafter, embodiments relating to a method for processing a resin substrate based on the present invention will be described in detail with reference to the attached drawings.

[0012] Figure 1 shows an overall perspective view of a cutting apparatus 1 suitable for carrying out the resin substrate processing method of this embodiment.

[0013] The cutting apparatus 1 includes a chuck table 10a that can hold and rotate a workpiece, a cutting means 8 that rotatably supports a cutting blade 83 for cutting the workpiece held on the chuck table 10a on a rotating shaft 82 extending in the Y-axis direction, an X-axis feed means (not shown) that feeds the chuck table 10a and the cutting means 8 relatively in the X-axis direction, a Y-axis feed means (not shown) that feeds the chuck table 10a and the cutting means 8 relatively in the Y-axis direction perpendicular to the X-axis direction, and a Z-axis feed means (not shown) that feeds the chuck table 10a and the cutting means 8 in the Z-axis direction perpendicular to both the X-axis and Y-axis directions. The holding surface of the chuck table 10a is a horizontal plane defined by the X-axis direction and the Y-axis direction as described above.

[0014] In addition to the above-described configuration, the cutting device 1 includes a housing 2 with a roughly rectangular parallelepiped shape, a cassette 4 placed on a cassette table 4a of the housing 2, an loading / unloading means 3 for loading a workpiece supported by a frame F from the cassette 4 to a temporary storage table 5, a transport means 6 for transporting the workpiece loaded onto the temporary storage table 5 to the chuck table 10a, an alignment means 9 for imaging the workpiece held on the chuck table 10a and detecting the area to be processed by the cutting means 8, and a cleaning / unloading means 14 for transporting the workpiece from the loading / unloading position where the chuck table 10a is positioned in Figure 1 to a cleaning device 12 (details omitted). Multiple clamps 10b are arranged at equal intervals around the outer circumference of the chuck table 10a. Furthermore, the dicing device 1 is equipped with control means and display means, etc., which are not shown in the illustration. In this embodiment, the X-axis feed mechanism is configured to move the chuck table 10a in the X-axis direction, and the Y-axis feed mechanism and Z-axis feed mechanism are configured to move the cutting mechanism 8 in the Y-axis direction and the Z-axis direction, respectively. All of these are located within the housing 2.

[0015] The cutting means 8 includes a rotating shaft housing 81 that rotatably supports a rotating shaft 82 extending in the Y-axis direction, and a blade cover 84 composed of multiple members that protect the cutting blade 83 mounted on the tip of the rotating shaft 82 (see also Figure 3(a)). A pair of cutting fluid supply means 85 (the opposite side is not visible) are arranged adjacent to the cutting blade 83 on either side of the blade cover 84, supplying cutting fluid introduced through the blade cover 84 towards the cutting position. A rotational drive source such as a motor (not shown) is housed at the other end of the rotating shaft housing 81, and this rotational drive source rotates the cutting blade 83 by rotating the rotating shaft 82.

[0016] The workpiece processed by the resin substrate processing method of this embodiment is, for example, a rectangular resin substrate 20 as shown in Figure 2. The resin substrate 20 is, for example, a substrate in which multiple semiconductor chips are mounted on a lead frame and bonded, and then sealed with a resin such as glass epoxy resin. The resin substrate 20 is formed with dimensions of 150 mm × 150 mm when viewed in plan, and the central rectangular central flat portion 21 has a thickness of 80 μm. Protrusions 23a to 23d are erected on the four sides of the outer periphery 22 of the central flat portion 21, and the protrusions 23a to 23d are formed with a thickness (height) of 1.5 to 4.0 mm and a width of 2 to 3 mm. The protrusions 23a to 23d are formed when resin accumulates on the outer periphery 22 during the process of coating the substrate on which multiple semiconductor chips are formed with resin, surrounding the central flat portion 21, and are not formed intentionally, so there is some variation in dimensions and shape.

[0017] When carrying out the resin substrate processing method of this embodiment, preferably, as shown in Figure 2, an annular frame F having an opening Fa in the center is prepared, the surface side of the resin substrate 20 is positioned downwards in the center of the opening Fa, and the resin substrate 20 is supported by the frame F via an adhesive sheet T to form an integral part (integration process). However, the present invention is not necessarily limited to including this integration process, and for example, if the cutting device 1 is equipped with a chuck table having a holding surface that matches the shape of the resin substrate 20, the above integration process can be omitted. If the integration process is omitted, it is preferable to prepare a sheet that matches the dimensions of the resin substrate 20 and attach it to the surface of the resin substrate 20.

[0018] Once the resin substrate 20 is prepared as described above, a holding process is performed to hold the resin substrate 20 on the chuck table 10a. More specifically, the resin substrate 20 is placed on the holding surface of the chuck table 10a with the sheet T side facing downwards, the frame F is gripped by the clamp 10b, and a suction means (not shown) is activated to generate negative pressure on the holding surface of the chuck table 10a, thereby holding the resin substrate 20 by suction.

[0019] Next, a convex portion flattening process is performed to cut the above-described convex portions 23a to 23d so that they have substantially the same height as the central flat portion 21. Referring to FIGS. 3 and 4 in addition to FIGS. 1 and 2, the convex portion flattening process will be described more specifically.

[0020] The cutting blade 83 attached to the cutting means 8 for performing the convex portion flattening process of the present embodiment is composed of, for example, a resin grinding wheel or a vitrified grinding wheel containing diamond abrasive grains, and a blade with a diameter of 50 mm and a thickness of 0.2 mm is selected.

[0021] When performing the convex portion flattening process, first, the resin substrate 20 is positioned directly below the alignment means 9 and imaged to detect the shape of the resin substrate 20, the positions of the convex portions 23a to 23d, etc. Next, as shown in FIG. 3(a), the resin substrate 20 is moved below the cutting means 8, and one side of the outer periphery 22 where any of the convex portions 23a to 23d of the resin substrate 20 is formed is positioned in the Y-axis direction (positioning step). In the present embodiment, the following description will be made on the assumption that the side where the illustrated convex portion 23a is first formed is positioned in the Y-axis direction.

[0022] Once the positioning step described above is performed, the X-axis feed means and Y-axis feed means are activated to position the tip of the cutting blade 83 on the extension of the Y-axis direction of the protrusion 23a of the resin substrate 20, near one end of the protrusion 23a, as shown in Figure 3(a). Next, the cutting blade 83 is rotated at a predetermined rotational speed (e.g., 10,000 rpm) in the direction indicated by arrow R1, and the Z-axis feed means is activated to position the tip of the cutting blade 83 so that it is, for example, 0.2 mm below the upper surface of the protrusion 23a (cutting feed step). Next, cutting fluid is supplied from the cutting fluid supply nozzle 85, and the Y-axis feed means described above is activated to move the cutting blade 83 at a predetermined feed speed (e.g., 50 mm / sec) in the Y-axis direction indicated by arrow R2 to the other end of the side, and the upper surface of the protrusion 23a is cut as shown in Figure 3(b) (flattening step). Here, depending on the width and height dimensions of the protrusion 23a, it may be possible to remove the protrusion 23a and substantially flatten one side of the resin substrate 20 in this single flattening step. However, if necessary, the process may be repeated by combining it with the index steps described below.

[0023] After performing the first cutting feed step and flattening step described above, the Y-axis feed means is activated to move the cutting means 8 to the position shown in Figure 3(a) on one end of the protrusion 23a in the Y-axis direction, and the X-axis feed means is activated according to the width of the protrusion 23a to perform an indexing step in which the resin substrate 20 is indexed by a predetermined amount (for example, 1 mm) toward the back in the X-axis direction. Next, the Y-axis feed means and Z-axis feed means are activated to perform the cutting feed step and flattening step described above to cut the upper surface of the protrusion 23a formed on the outer circumference 22 of the resin substrate 20 to a cutting depth of 0.2 mm. Furthermore, the indexing step, cutting feed step and flattening step described above are performed once more. As a result, the upper surface of the protrusion 23a is cut by 0.2 mm overall. Next, the X-axis feed mechanism described above is activated to position one side of the outer circumference 22 of the resin substrate 20 in the figure, where a protrusion 23b is formed opposite and parallel to the protrusion 23a, at the X-coordinate position of the position where the tip of the cutting blade 83 is positioned. The cutting feed step, flattening step, and indexing step performed on the protrusion 23a are also performed on the protrusion 23b, and the entire upper surface of the protrusion 23b is cut by 0.2 mm.

[0024] Furthermore, the resin substrate 20 is rotated 90 degrees, and one side of the outer circumference 22 where a protrusion 23c perpendicular to the protrusion 23b is formed is positioned at the X-coordinate of the position where the tip of the cutting blade 83 is located. Next, the above-described cutting feed step, flattening step, and indexing step are repeatedly executed to cut 0.2 mm off the entire upper surface of the protrusion 23c. Then, the above-described X-axis feed means is activated to position one side of the outer circumference of the resin substrate 20 in the figure where a protrusion 23d opposite to and parallel to the protrusion 23c is formed at the X-coordinate of the position where the tip of the cutting blade 83 is located, and the above-described cutting feed step, flattening step, and indexing step are repeatedly executed to cut 0.2 mm off the entire upper surface of the protrusion 23d formed on the outer circumference 22 of the resin substrate 20.

[0025] By performing the above-described cutting feed step, flattening step, and indexing step on the four sides of the outer circumference 22 on which the protrusions 23a to 23d are formed, the upper surfaces of the protrusions 23a to 23d are cut by 0.2 mm. Next, the above-described Z-axis feed means is activated to lower the position of the tip of the cutting blade 83 by another 0.2 mm and perform a cutting feed step, while simultaneously performing the flattening step and indexing step on the above-described protrusions 23a to 23d. By performing the above-described cutting feed step, flattening step, and indexing step on the above-described protrusions 23a to 23d, the upper surfaces of the protrusions 23a to 23d are cut by another 0.2 mm. The above-described cutting feed step, flattening step, and indexing step are repeatedly performed until the height of the outer perimeter 22 of the four sides of the resin substrate 20 is approximately the same height as the central flat portion 21. As shown in Figures 4(a) and (b), the protrusions 23a to 23d are removed and the resin substrate 20 is made flat, completing the protrusion flattening process. The order in which the protrusions 22a to 22d are subjected to the protrusion flattening process of the present invention is not particularly limited and can be performed in any order.

[0026] Furthermore, setting the feed rate for each cutting step and the index feed rate for each index step to smaller values ​​reduces the load on the cutting blade 83 and improves the flatness of the outer circumference 22 of the resin substrate 20. However, in this case, the number of flattening steps required increases, reducing production efficiency. Therefore, the feed rate for each cutting step and the index feed rate for each index step are set to minimize the number of steps required, taking into consideration the durability of the cutting blade 83 and the required processing quality (flatness).

[0027] Once the above-described convex flattening process is completed, the X-axis feed means and Y-axis feed means are activated to perform a splitting process in which the resin substrate 20 is divided into individual chips. In this embodiment, the cutting blade 83 of the cutting means 8 that performed the above-described convex flattening process is used as is to perform the splitting process.

[0028] In carrying out the division process shown in Figure 5, first, based on the information about the resin substrate 20 detected by the alignment means 9 described above, the chuck table 10a is rotated to align one side of the outer circumference 22 of the resin substrate 20 held by the chuck table 10a with the X-axis direction. Next, based on the position information of the planned division line of the resin substrate 20 (not shown) stored in advance in the control means, the cutting blade 83 is aligned with the planned division line along the X-axis direction, which will be the cutting start position. Then, the cutting blade 83, rotated at a predetermined rotational speed (e.g., 20,000 rpm) in the direction indicated by arrow R1, is positioned on the predetermined planned division line aligned with the X-axis direction, and a cut is made from the top surface to a depth of, for example, 0.1 mm, and the X-axis feed means is activated to process and feed the resin substrate 20 in the X-axis direction at a feed rate of, for example, 10 mm / second to form the division groove 100. Furthermore, the Y-axis feed mechanism is activated to index-feed the cutting blade 83 onto a division line adjacent in the Y-axis direction to a division line where a division groove 100 has been formed, but where no division groove 100 has been formed, and perform cutting to form a division groove 100 in the same manner as above. By repeating these steps, division grooves 100 are formed along all division lines along the X-axis direction. Next, the resin substrate 20 is rotated 90 degrees so that the direction perpendicular to the direction in which the division groove 100 was previously formed is aligned with the X-axis direction, and the above cutting process is performed on all division lines newly aligned with the X-axis direction to form division grooves 100 along all division lines of the resin substrate 20. By performing the division process in this manner, the resin substrate 20 can be divided into individual chips 24, as shown in Figure 5(b) (division process). This completes the processing method for the resin substrate of this embodiment.

[0029] According to the embodiment described above, when performing the division process to divide the resin substrate 20 into individual chips, the ridge-like protrusions 23a to 23d are removed from the outer circumference 22 of the resin substrate 20, making it substantially flat, thus eliminating the problem that these protrusions 23a to 23d would hinder the division of the resin substrate 20 into individual chips.

[0030] In the above-described embodiment, the cutting blade 83 was not changed in the convex portion flattening step and the splitting step, but the cutting blade may be changed as appropriate in each step. Furthermore, regarding the flattening step performed in the convex portion flattening step of the present invention, it is not excluded to position the cutting blade 83 so that one side of the outer circumference 22 of the resin substrate 20 is aligned with the X-axis direction, position it on the convex portion formed on the outer circumference 22, move it relative to it in the X-axis direction to cut the convex portion, and repeat this process to flatten the portion. However, as in the above-described embodiment, it is preferable to flatten the convex portion by positioning the tip of the cutting blade 83 on the convex portions 23a to 23d of the resin substrate 20 and moving it relative to it in the Y-axis direction. [Explanation of symbols]

[0031] 1:Cutting device 2: Housing 3: Carrying in / out means 4: Cassette 5: Temporary Table 6: Conveying means 8:Cutting means 81: Rotary shaft housing 82: Rotation axis 83: Cutting blade 84: Blade cover 9: Alignment Methods 10: Holding means 10a: Chuck Table 12: Washing equipment 14: Washing and removal means 20: Resin substrate 21: Central flat part 22: Perimeter 23a~23d: Convex part 24: Tip 100: Cutting groove F: Frame T: Seat

Claims

1. A method for processing a resin substrate having a convex portion on the outer circumference of a central flat portion, comprising a cutting apparatus comprising: a chuck table that can hold and rotate a workpiece; a cutting means for which a cutting blade for cutting the workpiece held on the chuck table is supported on a rotating axis extending in the Y-axis direction; an X-axis feeding means for feeding the chuck table and the cutting means relatively in the X-axis direction; a Y-axis feeding means for feeding the chuck table and the cutting means relatively in the Y-axis direction perpendicular to the X-axis direction; and a Z-axis feeding means for cutting the chuck table and the cutting means relatively in the Z-axis direction perpendicular to the X-axis and Y-axis directions, wherein the resin substrate having a convex portion on the outer circumference of a central flat portion is divided into individual chips. A holding process in which the resin substrate is held on a chuck table, A step of flattening a protrusion, in which the cutting blade is positioned on the outer circumference of the resin substrate and the protrusion is cut to make it approximately the same height as the central flat portion, A division step in which the resin substrate is divided into individual chips by operating the X-axis feed mechanism and the Y-axis feed mechanism, A method for processing a resin substrate comprising the above.

2. This process includes positioning a resin substrate in the opening of a frame having an opening in the center and integrating it with a sheet, The method for processing a resin substrate according to claim 1, wherein in the holding step, the sheet side is held on a chuck table.

3. The resin substrate is rectangular, and in the process of flattening the protrusions, A positioning step involves positioning one side of the resin substrate having a protrusion in the Y-axis direction, A flattening step in which the tip of the cutting blade is positioned on the protrusion of the resin substrate and moved relative to it in the Y-axis direction to flatten the protrusion, An indexing step is performed to relatively index the tip of the cutting blade and the protrusion of the resin substrate in the X-axis direction according to the width of the protrusion, A cutting step in which the tip of the cutting blade and the protrusion of the resin substrate are relatively fed in the Z-axis direction according to the height of the protrusion, Equipped with, The method for processing a resin substrate according to claim 1, wherein the planarization step, the indexing step, and the cutting step are repeated as needed.

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