JP6773554B2 - Package device chip manufacturing method and processing equipment - Google Patents

Description

The present invention relates to a method for manufacturing a package device chip and a processing apparatus.

As a processing method for dividing a semiconductor wafer into individual device chips, cutting processing with a cutting blade and ablation processing by irradiation with a pulse laser beam are known. The individually divided device chips are generally fixed to a mother substrate or the like, wired with wires or the like, and packaged with a mold resin. However, if the device chip is operated for a long time due to fine cracks on the side surface or the like, the cracks may extend and be damaged. In order to suppress such damage to the device chip, a packaging method has been developed in which the side surface of the device chip is covered with a mold resin to prevent external environmental factors from affecting the device chip (see, for example, Patent Document 1). ..

In addition to the packaging method shown in Patent Document 1, by so-called edge trimming that removes the mold resin on the outer periphery, the groove filled with the mold resin is exposed while removing the mold resin on the outer periphery, and the exposed groove is used as a reference. A method has been developed to determine the position where the package wafer should be divided and processed. According to this method, the position of the groove filled with the mold resin can be directly detected on the outer periphery of the substrate, so that the division position can be set accurately. However, if this position cannot be accurately recognized, the groove will be off-center and divided, resulting in a defective package chip having no mold resin on the side surface of the device chip. Therefore, the packaging method shown in Patent Document 1 requires precise position detection (alignment).

JP-A-2002-100709

However, the method of applying edge trimming to the packaging method shown in Patent Document 1 is a groove (filled with mold resin) that appears dark when a trimming saw mark is engraved on the surface of the outer peripheral edge exposed by the edge trimming process. If there is a crossover saw mark (appearing dark) between the substrate and the substrate, the boundary becomes ambiguous, which may interfere with precise position detection, and accurate alignment may not be possible.

The present invention has been made in view of these points, and an object of the present invention is to provide a method for manufacturing a packaged device chip and a processing apparatus capable of performing accurate alignment.

In order to solve the above-mentioned problems and achieve the object, in the method for manufacturing a package device chip of the present invention, a plurality of intersecting planned division lines are formed on the surface side, and a plurality of regions partitioned by the planned division lines are formed. A groove forming step of forming a groove along the planned division line on the surface side of the wafer on which the device is formed, and a package in which the groove is filled with a mold resin and the surface of the wafer is coated with the mold resin. Along the package wafer forming step of forming the wafer and the outer peripheral edge of the package wafer, the mold resin and the surface side of the wafer are removed by a cutting blade, and the groove filled with the mold resin and the wafer are removed from the outer peripheral edge. An alignment step of determining the position of the dividing groove of the package wafer formed along the groove based on the groove filled with the mold resin and exposed at the outer peripheral edge, and the alignment step. A dividing step for forming the dividing groove based on the position determined in step 1 is provided, and in the alignment step, the back surface side of the package wafer whose groove is exposed on the outer peripheral edge is held by a chuck table having a shining holding surface. The package wafer was imaged from the surface with an infrared camera, and the groove filled with the mold resin was dark because infrared rays did not pass through, and the wafers exposed on both sides of the groove transmitted infrared rays and were photographed brightly by the light of the illuminant. By doing so, a saw mark of the cutting blade from which the outer peripheral edge has been removed is formed at the boundary between the groove and the wafer, and the saw mark is prevented from interfering with the detection of the boundary.

The processing apparatus of the present invention has an infrared camera that captures a chuck table that holds a work piece on a holding surface, a processing unit that processes a work piece held on the chuck table, and a work piece held on the chuck table. A laser processing apparatus including an alignment unit that detects an area to be processed by imaging with an image and a control unit that controls each component, and the chuck table is a transparent or translucent holding that forms the holding surface. A workpiece having a member and a light emitting body installed on a surface side of the holding member opposite to the holding surface, and the alignment unit includes a region that transmits infrared rays and a region that does not transmit infrared rays. The infrared camera is used to image the image, and the region that transmits the infrared rays is brightened by the light of the illuminant, and the region that does not transmit the infrared rays is dark. And.

The processing unit may be a laser beam irradiation unit that irradiates a pulsed laser beam.

Therefore, in the method for manufacturing the package device chip and the processing apparatus of the present invention, the groove portion filled with the mold resin is darkened by using a chuck having a shining holding surface and an infrared camera, and the other wafer region is a light emitter. Since the light is transmitted and reflected brightly, it has the effect of being able to perform accurate alignment.

FIG. 1 is a perspective view showing a schematic configuration example of the laser processing apparatus according to the first embodiment. FIG. 2A is a perspective view of a wafer constituting the package wafer to be processed by the laser processing apparatus according to the first embodiment, and FIG. 2B is a device of the wafer shown in FIG. 2A. It is a perspective view of. FIG. 3 is a cross-sectional view of a main part of a package wafer to be processed by the laser processing apparatus according to the first embodiment. FIG. 4 is a perspective view showing a package device chip obtained by dividing the package wafer shown in FIG. FIG. 5 is a diagram showing a configuration of a chuck table of the laser processing apparatus shown in FIG. FIG. 6 is a cross-sectional view of a main part showing a state in which alignment of the laser processing apparatus shown in FIG. 1 is performed. FIG. 7 is a diagram showing an example of an image captured by an infrared camera at the time of alignment of the laser processing apparatus shown in FIG. FIG. 8 is a flowchart showing the flow of the manufacturing method of the package device chip according to the first embodiment. 9 (a) is a cross-sectional view of a main part of the wafer during the groove forming step of the package device chip manufacturing method shown in FIG. 8, and FIG. 9 (b) is a sectional view of the main part of the wafer shown in FIG. FIG. 9C is a cross-sectional view of a main part of the wafer after the groove forming step of the chip manufacturing method, and FIG. 9C is a perspective view of the wafer after the groove forming step of the package device chip manufacturing method shown in FIG. is there. FIG. 10 is a perspective view of the package wafer after the mold resin layer forming step of the method for manufacturing the package device chip shown in FIG. FIG. 11 is a cross-sectional view of a main part of the package wafer after the mold resin layer forming step of the method for manufacturing the package device chip shown in FIG. 12 (a) is a side view showing a thinning step of the package device chip manufacturing method shown in FIG. 8, and FIG. 12 (b) is a side view showing the packaging device chip manufacturing method shown in FIG. It is sectional drawing of the package wafer after a thinning step. FIG. 13 is a perspective view showing a replacement step of the method for manufacturing the package device chip shown in FIG. 14 (a) is a perspective view showing the outer peripheral edge removing step of the method for manufacturing the package device chip shown in FIG. 8, and FIG. 14 (b) is the method for manufacturing the package device chip shown in FIG. It is a perspective view of the package wafer after the outer peripheral edge removal step of. FIG. 15 is a perspective view showing an alignment step of the method for manufacturing the package device chip shown in FIG. FIG. 16 is a diagram showing a division step of the method for manufacturing the package device chip shown in FIG. FIG. 17 is a cross-sectional view of a main part of the package wafer after the division step of the method for manufacturing the package device chip shown in FIG.

An embodiment (embodiment) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiments. In addition, the components described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Further, the configurations described below can be combined as appropriate. In addition, various omissions, substitutions or changes of the configuration can be made without departing from the gist of the present invention.

[Embodiment 1]
The method for manufacturing the package device chip and the laser processing apparatus which is the processing apparatus according to the first embodiment will be described. FIG. 1 is a perspective view showing a schematic configuration example of the laser processing apparatus according to the first embodiment. FIG. 2A is a perspective view of a wafer constituting the package wafer to be processed by the laser processing apparatus according to the first embodiment. FIG. 2B is a perspective view of the wafer device shown in FIG. 2A. FIG. 3 is a cross-sectional view of a main part of a package wafer to be processed by the laser processing apparatus according to the first embodiment. FIG. 4 is a perspective view showing a package device chip obtained by dividing the package wafer shown in FIG.

As the method for manufacturing the package device chip according to the first embodiment, the laser processing apparatus 1 shown in FIG. 1 is used in a part of the manufacturing process. The laser processing apparatus 1 shown in FIG. 1 is an apparatus that ablates the scheduled division line L of the package wafer PW shown in FIG. 3 which is an workpiece and divides it into the package device chip PD shown in FIG. The package wafer PW to be processed by the laser processing apparatus 1 according to the first embodiment is composed of the wafer W shown in FIG. In the first embodiment, the wafer W shown in FIG. 2A is a disk-shaped semiconductor wafer or optical device wafer using silicon, sapphire, gallium arsenide, or the like as a substrate SB. The substrate SB constituting the wafer W transmits infrared rays. As shown in FIG. 2A, in the wafer W, a plurality of intersecting scheduled division lines L (orthogonal in the first embodiment) are formed on the surface WS side. The wafer W includes a device region DR in which the device D is formed in a plurality of regions partitioned by the planned division line L, and an outer peripheral surplus region GR surrounding the device region DR on the surface WS. As shown in FIG. 2B, bump BPs, which are a plurality of protruding electrodes, are formed on the surface of the device D.

As shown in FIG. 3, in the wafer W, the surface WS of the device region DR and the groove DT formed on the scheduled division line L along the scheduled division line L are covered with the mold resin MR. It is composed of a package wafer PW. That is, in the package wafer PW, the mold resin MR is filled in the groove DT between the device D and the device D provided on the surface WS of the substrate SB. The mold resin MR is formed by mixing carbon with a synthetic resin, and is formed in black, which is difficult to transmit infrared rays. As shown in FIG. 1, the package wafer PW is subjected to ablation processing after the mold resin MR on the outer peripheral edge is removed over the entire circumference to expose the substrate SB in the outer peripheral surplus region GR.

The mold resin MR of the outer peripheral surplus region GR of the package wafer PW is removed over the entire circumference, and the mold resin MR filled in the groove DT of the region where the substrate SB of the outer peripheral surplus region GR is exposed is a mold resin. Since MR does not easily transmit infrared rays, this is a region that does not transmit infrared rays. Further, in the exposed substrate SB in the region where the mold resin MR of the outer peripheral surplus region GR of the package wafer PW is removed over the entire circumference and the substrate SB of the outer peripheral surplus region GR is exposed, the substrate SB transmits infrared rays. Therefore, it is a region that transmits infrared rays.

In the package wafer PW, the mold resin MR filled in the groove DT formed in the scheduled division line L is divided and divided into the package device chip PD shown in FIG. In the package device chip PD, the device D provided on the surface WS of the substrate SB and all the side surface SDs are covered with the mold resin MR, and the bump BP protrudes from the mold resin MR to expose the bump BP. ..

In the first embodiment, the width of the groove DT of the package wafer PW is narrower than that of the package wafer PW divided into the package device chip PD by the cutting blade, for example, 40 μm to 80 μm. In the first embodiment, the thickness of the package wafer PW (also referred to as the finished thickness) is thicker than that of the semiconductor wafer divided into devices, for example, 700 μm to 200 μm. In the first embodiment, the planar shape of the package device chip PD is formed into, for example, a quadrangle having a side of 3 mm. Further, in the first embodiment, in the package wafer PW, the molded resin MR filled in the groove DT is irradiated with the pulsed laser beam LR by the laser beam irradiation unit 20 which is the processing unit of the laser processing apparatus 1 as shown in FIG. Then, a split groove PG having a width of 15 μm to 30 μm is formed in the mold resin MR filled in the groove DT. In the first embodiment, the thickness of the mold resin MR on the side surface SD of the substrate SB of the package device chip PD is 7.5 μm to 25 μm.

Next, the configuration of the laser processing apparatus 1 according to the first embodiment will be described with reference to the drawings. FIG. 5 is a diagram showing a configuration of a chuck table of the laser processing apparatus shown in FIG. FIG. 6 is a cross-sectional view of a main part showing a state in which alignment of the laser processing apparatus shown in FIG. 1 is performed. FIG. 7 is a diagram showing an example of an image captured by an infrared camera at the time of alignment of the laser processing apparatus shown in FIG.

The laser processing device 1 irradiates the mold resin MR in the groove DT of the package wafer PW with a pulsed laser beam LR (shown in FIG. 3), ablates the package wafer PW, and transfers the package wafer PW to the package device chip PD. It is a device for dividing. As shown in FIG. 1, the laser machining apparatus 1 includes a chuck table 10 that holds the package wafer PW on the holding surface 11a, a laser beam irradiation unit 20 that is a machining unit, an X-axis moving means 30 that is a machining feed unit, and the like. It includes a Y-axis moving means 40 which is an indexing feed unit, an infrared camera 50, and a control unit 60.

The X-axis moving means 30 moves the chuck table 10 in the X-axis direction, which is the machining feed direction parallel to the horizontal direction of the apparatus main body 2, so that the chuck table 10 and the laser beam irradiation unit 20 are relative to each other in the X-axis direction. It is to move to. The Y-axis moving means 40 moves the chuck table 10 in the Y-axis direction, which is the indexing feed direction orthogonal to the X-axis direction, parallel to the horizontal direction, thereby moving the chuck table 10 and the laser beam irradiation unit 20 in the Y-axis direction. It is a relative movement.

The X-axis moving means 30 and the Y-axis moving means 40 are well-known pulse motors 32, 42 for rotating well-known ball screws 31, 41 and ball screws 31, 41 rotatably provided around the axis center. Also provided are well-known guide rails 33 and 43 that movably support the chuck table 10 in the X-axis direction or the Y-axis direction. Further, the X-axis moving means 30 includes an X-axis direction position detecting means (not shown) for detecting the position of the chuck table 10 in the X-axis direction, and the Y-axis moving means 40 determines the position of the chuck table 10 in the Y-axis direction. A Y-axis direction position detecting means (not shown) for detecting is provided. The X-axis direction position detecting means and the Y-axis direction position detecting means can be composed of a linear scale parallel to the X-axis direction or the Y-axis direction and a reading head. The X-axis direction position detecting means and the Y-axis direction position detecting means output the position of the chuck table 10 in the X-axis direction or the Y-axis direction to the control unit 60. Further, the laser machining apparatus 1 includes a rotation drive source 16 that rotates the chuck table 10 around a central axis parallel to the Z-axis direction orthogonal to both the X-axis direction and the Y-axis direction. The rotation drive source 16 is arranged on a moving table 15 that is moved in the X-axis direction by the X-axis moving means 30.

The laser beam irradiation unit 20 irradiates the pulsed laser beam LR from above toward the surface WS of the package wafer PW held on the holding surface 11a of the chuck table 10 to ablate the package wafer PW (corresponding to processing). A division groove PG (shown in FIG. 3) is formed in the mold resin MR filled in the groove DT of the planned division line L. The pulsed laser beam LR is a pulsed laser beam having a wavelength (for example, 355 nm) that is absorbent to the molded resin MR filled in the groove DT of the package wafer PW and having a constant laser power. The laser beam irradiation unit 20 is attached to the tip of a support column 4 connected to a wall portion 3 erected from the device main body 2.

The laser beam irradiation unit 20 includes a condensing lens (not shown) that condenses the pulsed laser beam LR that irradiates the surface of the package wafer PW, a drive mechanism (not shown) that moves the condensing point of the pulsed laser beam LR in the Z-axis direction, and a pulsed laser beam. It includes a laser beam oscillating unit (not shown) that oscillates LR. The laser beam oscillation unit oscillates a pulsed laser beam LR having a wavelength of 355 nm at a set repetition frequency. In the first embodiment, the optical axis of the pulsed laser beam LR irradiated by the laser beam irradiation unit 20 toward the surface WS of the package wafer PW is parallel to the Z-axis direction.

The laser beam irradiation unit 20 is moved relative to the package wafer PW held on the chuck table 10 by the X-axis moving means 30 and the Y-axis moving means 40, and is molded in the groove DT of each scheduled division line L. The resin MR is irradiated with a pulsed laser beam LR to form a dividing groove PG (shown in FIG. 17) along each scheduled division line L in the molded resin MR in the groove DT. The laser beam irradiation unit 20 irradiates the mold resin MR in the groove DT of each scheduled division line L with the pulsed laser beam LR while being moved a plurality of times relative to the package wafer PW along the X-axis direction.

The infrared camera 50 captures the package wafer PW held on the chuck table 10. The infrared camera 50 is arranged at a position parallel to the laser beam irradiation unit 20 in the X-axis direction. In the first embodiment, the infrared camera 50 is attached to the tip of the support column 4. The infrared camera 50 is composed of an InGaAs having a wavelength sensitivity range of 0.9 μm to 1.7 μm, an InSb having a wavelength sensitivity range of 1.5 μm to 5.0 μm, or an amorphous Si microbolometer having a wavelength sensitivity range of 7 μm to 14 μm. It is a camera having an infrared detection element.

Further, the laser processing apparatus 1 includes a cassette 71 that accommodates a plurality of package wafers PW supported by the annular frame F by the dicing tape T, and a cassette elevator 70 on which the cassette 71 is placed and the cassette 71 is moved in the Z-axis direction. And. The laser processing apparatus 1 takes out the package wafer PW before ablation processing from the cassette 71, and houses the package wafer PW after ablation processing in the cassette 71 as shown as a carrying-in / out means, and the package before ablation processing taken out from the cassette 71. The wafer PW and the cassette 71 after the ablation process are provided with a pair of rails 72 for temporarily placing the pre-accommodated package wafer PW. The laser machining apparatus 1 includes a cleaning unit 90 for cleaning the package wafer PW after ablation processing, and a transfer unit 80 for transporting the package wafer PW between the pair of rails 72, the chuck table 10 and the cleaning unit 90.

As shown in FIG. 5, the chuck table 10 has a transparent or semi-transparent holding member 11 forming the holding surface 11a, an annular frame portion 12 formed by surrounding the holding member 11, and a holding surface of the holding member 11. It has a light emitting body 13 installed on the surface side opposite to 11a. The holding member 11 is formed in a disk shape having a thickness of 2 mm to 5 mm, and is made of, for example, quartz. The upper surface of the holding member 11 functions as a holding surface 11a for holding the package wafer PW.

The annular frame portion 12 is formed so as to surround the outer circumference and the lower surface side of the holding member 11. As shown in FIG. 5, the surface WS of the annular frame portion 12 is arranged in the same plane as the holding surface 11a. The annular frame portion 12 is attached to the rotary drive source 16. Further, the annular frame portion 12 is provided with a suction path 12a which is opened at the outer edge of the holding member 11 and is connected to a vacuum suction source (not shown).

The light emitting body 13 is attached to the annular frame portion 12 and is arranged to face the lower surface of the holding member 11 to illuminate the package wafer PW via the holding member 11. The light emitting body 13 is composed of a plurality of LEDs (Light Emitting Diodes) 13a. Each LED 13a is connected to a power supply circuit (not shown). When power is supplied to each LED 13a from the power supply circuit, the light emitting body 13 emits light and irradiates the light from the lower surface side of the holding member 11 toward the upper surface side. The holding surface 11a of the chuck table 10 shines when the light emitting body 13 emits light.

The chuck table 10 is provided so as to be movable in the X-axis direction by the X-axis moving means 30 and rotatably around the axis by the rotational drive source 16 because the annular frame portion 12 is attached to the rotary drive source 16. ing. Further, in the chuck table 10, the package wafer PW held by the annular frame F is placed on the holding surface 11a via the dicing tape T and sucked by the vacuum suction source to suck and hold the package wafer PW. Further, a clamp portion 14 for clamping the annular frame F is provided on the outer periphery of the chuck table 10.

The control unit 60 controls each of the above-described components of the laser processing device 1 to cause the laser processing device 1 to perform a processing operation on the package wafer PW. The control unit 60 is a computer. The control unit 60 is connected to a display device (not shown) composed of a liquid crystal display device for displaying the state of machining operation, an image, or the like, and an input device (not shown) used by an operator when registering machining content information or the like. The input device is composed of at least one of a touch panel provided with a display device and an external input device such as a keyboard.

The control unit 60 includes an alignment unit 61 that detects a region to be processed by imaging the package wafer PW held on the chuck table 10 with the infrared camera 50. The alignment unit 61 performs alignment for detecting the position where the pulsed laser beam LR of the package wafer PW should be irradiated before the ablation processing of the package wafer PW. When the alignment unit 61 performs alignment, as shown in FIG. 6, all the LEDs 13a of the light emitting body 13 of the chuck table 10 are turned on, and the groove exposed on the outer peripheral edge of the outer peripheral surplus area GR of the package wafer PW. Each of the DTs is imaged by the infrared camera 50. The alignment unit 61 is formed on each scheduled division line L based on the image IP shown in FIG. 7 obtained by imaging and the detection results of the X-axis direction position detecting means and the Y-axis direction position detecting means. The position where the pulsed laser beam LR of the groove DT should be irradiated is detected, that is, the position of the dividing groove PG is determined.

In the image IP captured by the infrared camera 50, the mold resin MR does not easily transmit infrared rays, and the substrate SB transmits infrared rays. Therefore, the exposed substrate SB of the outer peripheral excess region GR is filled in the groove DT. Brighter than. That is, in the image IP shown in FIG. 7, the exposed substrate SB in the outer peripheral surplus region GR is brightened by the light of the light emitter 13, and the molded resin MR filled in the groove DT is darkly imaged. In the first embodiment, the alignment unit 61 is preset between the amount of infrared light received by the infrared camera 50 through the substrate SB and the amount of infrared light received by the infrared camera 50 through the molded resin MR filled in the groove DT. The threshold value is stored, and the region above the threshold value is shown by a white background as shown in FIG. 7, and the region below the threshold value is shown by a black background as shown by a parallel diagonal line in FIG. The alignment unit 61 detects the position of the mold resin MR filled in the groove DT by detecting the edge of the region below the threshold value, and performs the alignment. In this way, the alignment unit 61 is imaged by the infrared camera 50, the substrate SB that transmits infrared rays is brightened by the light of the light emitter 13, and the molded resin MR that does not transmit infrared rays is imaged darkly. Perform PW alignment.

Next, a method of manufacturing the package device chip according to the first embodiment will be described with reference to the drawings. FIG. 8 is a flowchart showing the flow of the manufacturing method of the package device chip according to the first embodiment. FIG. 9A is a cross-sectional view of a main part of the wafer during the groove forming step of the method for manufacturing the package device chip shown in FIG. FIG. 9B is a cross-sectional view of a main part of the wafer after the groove forming step of the method for manufacturing the package device chip shown in FIG. FIG. 9 (c) is a perspective view of the wafer after the groove forming step of the method for manufacturing the package device chip shown in FIG. FIG. 10 is a perspective view of the package wafer after the mold resin layer forming step of the method for manufacturing the package device chip shown in FIG. FIG. 11 is a cross-sectional view of a main part of the package wafer after the mold resin layer forming step of the method for manufacturing the package device chip shown in FIG. FIG. 12A is a side view showing a thinning step of the method for manufacturing the package device chip shown in FIG. FIG. 12B is a cross-sectional view of the package wafer after the thinning step of the method for manufacturing the package device chip shown in FIG. FIG. 13 is a perspective view showing a replacement step of the method for manufacturing the package device chip shown in FIG. FIG. 14A is a perspective view showing the outer peripheral edge removing step of the method for manufacturing the package device chip shown in FIG. FIG. 14B is a perspective view of the package wafer after the outer peripheral edge removing step of the method for manufacturing the package device chip shown in FIG. FIG. 15 is a perspective view showing an alignment step of the method for manufacturing the package device chip shown in FIG. FIG. 16 is a diagram showing a division step of the method for manufacturing the package device chip shown in FIG. FIG. 17 is a cross-sectional view of a main part of the package wafer after the division step of the method for manufacturing the package device chip shown in FIG.

The method for manufacturing a package device chip PD according to the first embodiment (hereinafter, simply referred to as a manufacturing method) is a method in which a package wafer PW is manufactured from a wafer W and then the package wafer PW is divided into package device chip PDs. As shown in FIG. 8, the manufacturing method according to the first embodiment aligns the groove forming step ST1, the mold resin layer forming step ST21, the thinning step ST22, the replacement step ST3, and the outer peripheral edge removing step ST4. A step ST5 and a division step ST6 are provided.

The groove forming step ST1 is a step of forming a groove DT along the scheduled division line L on the surface WS side of the wafer W. The depth of the groove DT formed in the groove forming step ST1 is equal to or larger than the finished thickness of the package wafer PW. In the first embodiment, the groove forming step ST1 sucks and holds the back surface WR on the back side of the front surface WS of the wafer W on the holding surface of the chuck table of the cutting apparatus 110, and as shown in FIG. 9A, the cutting apparatus 110 As shown in FIG. 9B, a groove DT is formed on each scheduled division line L of the surface WS of the wafer W by using the cutting blade 113 of the cutting means 112 of the above.

In the groove forming step ST1, the chuck table is moved in the X-axis direction parallel to the horizontal direction by an X-axis moving means (not shown), and the cutting blade 113 of the cutting means 112 is parallel to the horizontal direction and in the X-axis direction by the Y-axis moving means. The cutting blade 113 of the cutting means 112 is moved in the Z-axis direction parallel to the vertical direction by the Z-axis moving means, and each of the wafers W is moved as shown in FIG. 9C. A groove DT is formed on the surface WS of the planned division line L. In the present invention, the groove forming step ST1 may form the groove DT by ablation processing using a laser beam.

As shown in FIGS. 10 and 11, the mold resin layer forming step ST21 is a step of covering the surface WS of the device region DR of the wafer W with the mold resin MR and filling the groove DT with the mold resin MR. In the first embodiment, in the mold resin layer forming step ST21, the back surface WR of the wafer W is held on a holding table of a resin coating device (not shown), the mold resin MR is dropped on the front surface WS of the wafer W, and the holding table is vertically oriented. By rotating around the axis parallel to the above, the entire surface WS and the groove DT are covered with the mold resin MR. In the first embodiment, a thermosetting resin is used as the mold resin MR. In the mold resin layer forming step ST21, the mold resin MR covering the entire surface WS of the wafer W and the groove DT is heated and cured. Further, in the first embodiment, the bump BP is exposed when the entire surface WS and the groove DT are covered with the mold resin MR. However, in the present invention, the cured mold resin MR is polished and the bump BP is exposed. May be ensured to be exposed.

The thinning step ST22 is a step of thinning the substrate SB of the package wafer PW in which the wafer W is covered with the mold resin MR to the finished thickness. In the thinning step ST22, as shown in FIG. 12A, after the protective member PP is attached to the mold resin MR side of the package wafer PW, the protective member PP is attached to the holding surface 121a of the chuck table 121 of the grinding device 120. The grinding wheel 122 is brought into contact with the back surface WR of the package wafer PW while being sucked and held, and the chuck table 121 and the grinding wheel 122 are rotated around the axis to grind the back surface WR of the package wafer PW. In the thinning step ST22, as shown in FIG. 12B, the package wafer PW is thinned until the mold resin MR filled in the groove DT is exposed. In the mold resin layer forming step ST21 and the thinning step ST22 described above, the groove DT is filled with the mold resin MR and the surface WS of the wafer W is covered with the mold resin MR to form the package wafer PW. To configure.

The reattachment step ST3 is a step of peeling off the protective member PP from the package wafer PW and attaching the dicing tape T. In the reattachment step ST3, as shown in FIG. 13, the back surface WR of the package wafer PW is attached to the dicing tape T to which the annular frame F is attached to the outer periphery, and the protective member PP is peeled off from the front surface WS.

In the outer peripheral edge removing step ST4, the mold resin MR and the surface WS side of the wafer W are removed by the cutting blade 115 shown in FIG. 14 (a) along the outer peripheral edge of the package wafer PW, and the groove filled with the mold resin MR is formed. This is a step of exposing the substrate SB of the DT and the wafer W at the outer peripheral edge of the outer peripheral surplus area GR. In the first embodiment, the outer peripheral edge removing step ST4 removes the mold resin MR over the entire outer peripheral edge of the outer peripheral surplus region GR of the package wafer PW.

In the first embodiment, in the outer peripheral edge removing step ST4, similarly to the groove forming step ST1, as shown in FIG. 14A, the back surface WR of the package wafer PW is sucked onto the holding surface 111a of the chuck table 111 of the cutting device 110. While holding and rotating the chuck table 111 around the axis parallel to the Z-axis direction with the rotation drive source 114, the cutting blade 115 is cut into the mold resin MR on the outer peripheral edge of the outer peripheral surplus region GR until it reaches the substrate SB. Then, the groove DT filled with the mold resin MR is exposed on the outer peripheral edge of the outer peripheral surplus region GR. In the outer peripheral edge removing step ST4, as shown in FIG. 14B, the mold resin MR on the outer peripheral edge of the outer peripheral surplus region GR of the package wafer PW is removed. Note that the bump BP is omitted in FIGS. 13, 14 (a) and 14 (b). Further, in the outer peripheral edge removing step ST4, a cutting mark (also referred to as a saw mark) (also referred to as a saw mark) formed by the cutting blade 115 is formed on the surface of the substrate SB exposed in the outer peripheral surplus region GR.

The alignment step ST5 and the division step ST6 are performed by the laser processing apparatus 1. A plurality of package wafers PW in which the outer peripheral edge removing step ST4 has been performed are housed in the cassette 71 by the operator, and the cassette 71 containing a plurality of package wafer PWs is placed in the cassette elevator 70 of the laser processing apparatus 1 by the operator. To. When the operator registers the machining content information in the control unit 60 of the laser machining device 1 and the operator gives an instruction to start the machining operation, the laser machining device 1 starts the machining operation and executes the alignment step ST5.

The alignment step ST5 is a step of determining the position of the dividing groove PG of the package wafer PW formed along the groove DT based on the groove DT filled with the mold resin MR and exposed at the outer peripheral edge. In the alignment step ST5, the control unit 60 causes the loading / unloading means to take out one package wafer PW before ablation processing from the cassette 71 and place it on the pair of rails 72. In the control unit 60, the package wafer PW on the pair of rails 72 is placed on the holding surface 11a of the holding member 11 of the chuck table 10 on the transport unit 80, and is sucked and held on the holding surface 11a of the holding member 11 of the chuck table 10. , The light emitter 13 is made to emit light.

The control unit 60 moves the chuck table 10 toward the lower side of the laser beam irradiation unit 20 by the X-axis moving means 30, and as shown in FIG. 15, the package wafer held on the chuck table 10 below the infrared camera 50. Position the PW. In the alignment step ST5, the alignment unit 61 holds the back surface WR side of the package wafer PW whose groove DT is exposed on the outer peripheral edge with the chuck table 10, and images the surface of the package wafer PW along the outer peripheral edge with the infrared camera 50. ..

In the alignment step ST5, when the infrared camera 50 takes an image, the alignment unit 61 causes the infrared camera 50 to sequentially take an image of the groove DT formed in each of the planned division lines L exposed in the outer peripheral surplus region GR of the package wafer PW. In the alignment step ST5, the alignment unit 61 generates the image IP shown in FIG. 7 based on the amount of infrared light received by the infrared camera 50. Since the image IP shown in FIG. 7 is generated based on the amount of infrared light received by the infrared camera 50, it is possible to suppress the appearance of the saw mark on the image IP. This is because the saw mark is a cutting mark formed on the surface of the substrate SB of the wafer W of the package wafer PW and therefore does not affect the infrared transmittance.

In the alignment step ST5, the alignment unit 61 determines the position of the dividing groove PG formed on each scheduled division line L from the image IP and performs the alignment. As described above, in the alignment step ST5, by performing the alignment based on the image IP shown in FIG. 7, the groove DT filled with the mold resin MR is dark because infrared rays do not pass through, and is exposed on both sides of the groove DT. The substrate SB of the wafer W transmits infrared rays and is photographed brightly by the light of the light emitter 13, so that the saw mark of the cutting blade 113 from which the outer peripheral edge is removed is formed at the boundary between the groove DT and the wafer W substrate SB in the image IP. , It is possible to prevent the saw mark from interfering with the detection of the boundary, that is, the edge of the dividing groove PG.

The division step ST6 is a step of forming the division groove PG based on the position determined in the alignment step ST5. In the division step ST6, the control unit 60 controls the X-axis moving means 30 and the Y-axis moving means 40 to move the chuck table 10 based on the alignment result of the alignment unit 61, as shown in FIG. , The laser beam LR is irradiated from the laser beam irradiation unit 20 to the mold resin MR filled in each groove DT. In the division step ST6, as shown in FIG. 17, the control unit 60 forms the division groove PG in the mold resin MR filled in each groove DT.

After performing the division step ST6, the control unit 60 retracts the chuck table 10 from below the laser beam irradiation unit 20 and stops it at a position closer to the pair of rails 72, turns off the light emitting body 13, and turns off the light emitter 13 and the chuck table 10. Release the suction holding of. Then, the control unit 60 transports the ablated package wafer PW to the cleaning unit 90 using the transport unit 80, cleans the package wafer PW with the cleaning unit 90, and then accommodates the cleaned package wafer PW in the cassette 71.

The control unit 60 ablates all the package wafers PW in the cassette 71 in order. When all the package wafers PW in the cassette 71 are subjected to ablation processing, the control unit 60 ends the processing operation.

The control unit 60 described above includes an arithmetic processing device having a microprocessor such as a CPU (central processing unit), a storage device having a memory such as a ROM (read only memory) or a RAM (random access memory), and input / output. It has an interface device. The arithmetic processing unit of the control unit 60 performs arithmetic processing according to a computer program stored in the storage device, and sends a control signal for controlling the laser processing apparatus 1 to the laser processing apparatus 1 via an input / output interface apparatus. Output to the above-mentioned components of. Further, the functions of the control unit 60 and the alignment unit 61 are realized by the arithmetic processing unit executing a computer program stored in the storage device and storing necessary information in the storage device.

In the manufacturing method and the laser processing apparatus 1 according to the first embodiment, in the alignment step ST5, the light emitter 13 of the chuck table 10 is made to emit light, and the alignment unit 61 is divided based on the image IP obtained by the infrared camera 50. The position of the groove PG is determined. Since the saw mark formed on the surface of the substrate SB of the wafer W of the package wafer PW does not affect the transmittance of infrared rays, the groove DT filled with the mold resin MR is dark in the image IP, and the other wafers. The light of the light emitting body 13 is transmitted through the substrate SB of W and the light is reflected brightly. In the image IP imaged by the infrared camera 50 and not affected by the saw mark, the boundary between the mold resin MR filled in the groove DT and the surface of the substrate SB of the wafer W is linear along the outer edge of the groove DT. Become. As a result, the manufacturing method and the laser processing apparatus 1 according to the first embodiment can accurately determine the position of the dividing groove PG.

The present invention is not limited to the above embodiment. That is, it can be modified in various ways without departing from the gist of the present invention.

1 Laser machining equipment 10 Chuck table 11 Holding member 11a Holding surface 13 Luminous body 20 Laser beam irradiation unit (machining unit)
50 Infrared camera 60 Control unit 61 Alignment unit 113 Cutting blade PW package wafer (workpiece)
PD Package device chip W Wafer WS Front surface WR Back surface L Scheduled division line LR Pulse laser beam D device DT groove (area to be machined)
MR mold resin (area that does not transmit infrared rays)
PG dividing groove SB substrate (region that transmits infrared rays)
DR device area GR outer peripheral surplus area ST1 groove formation step ST2 package wafer formation step ST4 outer peripheral edge removal step ST5 alignment step ST6 division step

Claims (3)

It is a manufacturing method of packaged device chips.
A groove forming a groove along the planned division line on the surface side of the wafer in which a plurality of intersecting planned division lines are formed on the surface side and devices are formed in a plurality of regions partitioned by the planned division line. The formation step and
A package wafer forming step of filling the groove with a mold resin and covering the surface of the wafer with the mold resin to form a package wafer.
Along the outer peripheral edge of the package wafer, the outer peripheral edge removing step of removing the mold resin and the surface side of the wafer with a cutting blade, and exposing the groove filled with the mold resin and the wafer on the outer peripheral edge.
An alignment step of determining the position of the dividing groove of the package wafer formed along the groove based on the groove filled with the mold resin and exposed at the outer peripheral edge.
A division step for forming the division groove based on the position determined in the alignment step is provided.
In the alignment step
The back surface side of the package wafer whose groove is exposed on the outer peripheral edge is held by a chuck table whose holding surface shines, the package wafer is imaged from the front surface with an infrared camera, and the groove filled with the mold resin transmits infrared rays. Wafers exposed on both sides of the groove are dark because they do not, and are photographed brightly by the light of the illuminant through infrared rays, so that the saw mark of the cutting blade from which the outer peripheral edge is removed is the boundary between the groove and the wafer. A method of manufacturing a packaged device chip, which is formed on a wafer and prevents the saw mark from interfering with the detection of the boundary. A chuck table that holds the work piece on the holding surface, a processing unit that processes the work piece held on the chuck table, and an area to be processed by imaging the work piece held on the chuck table with an infrared camera. A laser machining apparatus including an alignment unit for detecting infrared rays and a control unit for controlling each component.
The chuck table is
A transparent or translucent holding member forming the holding surface,
The holding member has a light emitting body installed on a surface side opposite to the holding surface.
The alignment unit
An image of a work piece including a region that transmits infrared rays and a region that does not transmit infrared rays is imaged by the infrared camera, the region that transmits infrared rays is brightened by the light of the illuminant, and the region that does not transmit infrared rays is imaged dark. A processing device characterized in that alignment of a workpiece is performed by utilizing the characteristics of the work piece. The processing apparatus according to claim 2, wherein the processing unit is a laser beam irradiation unit that irradiates a pulsed laser beam.

Images