JP4777701B2 - Method for separating adhesive film - Google Patents

Description

  The present invention relates to an adhesive film separating method for separating an adhesive film for die bonding mounted on a back surface of a semiconductor wafer divided into a plurality of semiconductor chips.

  For example, in a semiconductor device manufacturing process, devices such as IC and LSI are formed in a plurality of regions partitioned by streets (planned cutting lines) formed in a lattice shape on the surface of a semiconductor wafer having a substantially disk shape, Individual semiconductor chips are manufactured by dividing each region in which the device is formed along a street. A dicing apparatus is generally used as a dividing apparatus for dividing a semiconductor wafer, and the dicing apparatus cuts the semiconductor wafer along the street with a cutting blade having a thickness of about 20 μm. The semiconductor chip thus divided is packaged and widely used in electric devices such as mobile phones and personal computers.

Individually divided semiconductor chips are mounted on the back with an adhesive film for die bonding called die attach film with a thickness of 20 to 40 μm formed of polyimide resin, epoxy resin, acrylic resin fat, etc. Bonding is performed by heating to a die bonding frame that supports the semiconductor chip via this adhesive film. As a method of attaching the adhesive film for die bonding to the back surface of the semiconductor chip, the adhesive film is attached to the back surface of the semiconductor wafer, the semiconductor wafer is attached to the dicing tape through the adhesive film, and then the semiconductor wafer By cutting along with the adhesive film with a cutting blade along the street formed on the front surface, a semiconductor chip having the adhesive film mounted on the back surface is formed. (For example, refer to Patent Document 1.)
JP 2000-182959 A

  However, according to the method disclosed in Japanese Patent Application Laid-Open No. 2000-182959, when the adhesive film is cut together with the semiconductor wafer by a cutting blade and divided into individual semiconductor chips, chipping occurs on the back surface of the semiconductor chip or adhesion occurs. There is a problem in that wrinkle-like burrs are generated in the film and cause breakage during wire bonding.

  In recent years, electric devices such as mobile phones and personal computers are required to be lighter and smaller, and a thinner semiconductor chip is required. As a technique for dividing the semiconductor chip thinner, a so-called dicing method called a dicing method has been put into practical use. In this tip dicing method, a divided groove having a predetermined depth (a depth corresponding to the finished thickness of the semiconductor chip) is formed along the street from the surface of the semiconductor wafer, and then the semiconductor wafer having the divided grooves formed on the surface thereof. In this technique, the rear surface of the semiconductor chip is ground so that the dividing grooves are exposed on the rear surface and separated into individual semiconductor chips. The thickness of the semiconductor chip can be reduced to 50 μm or less.

  However, when a semiconductor wafer is divided into individual semiconductor chips by the tip dicing method, a back surface of the semiconductor wafer is ground by forming a dividing groove having a predetermined depth along the street from the surface of the semiconductor wafer. Therefore, the die bonding adhesive film cannot be attached to the back surface of the semiconductor wafer in advance. Therefore, when bonding to the die bonding frame that supports the semiconductor chip by the prior dicing method, the bonding agent must be inserted between the semiconductor chip and the die bonding frame, and the bonding operation is performed smoothly. There is a problem that can not be.

In order to eliminate such problems, after attaching an adhesive film for die bonding to the back surface of each semiconductor chip divided by the prior dicing method, and attaching the semiconductor chip to the dicing tape via this adhesive film A semiconductor chip in which the portion of the adhesive film exposed in the gap between the semiconductor chips is irradiated with a laser beam from the surface side of the semiconductor chip through the gap to remove the portion of the adhesive film exposed in the gap. The manufacturing method of this is proposed. (For example, see Patent Document 2.)
JP 2002-118081 A

Also, after attaching a die bonding adhesive film to the backside of the semiconductor wafer divided into individual semiconductor chips by dicing, and sticking the adhesive film side of the semiconductor wafer to the dicing tape, the dicing tape side into the dividing groove A method of manufacturing a semiconductor chip is also proposed in which the adhesive film is irradiated with a laser beam having a wavelength that is not absorbed by the dicing tape but is absorbed by the adhesive film, and the adhesive film is melted along the dividing grooves. (For example, refer to Patent Document 3.)
Japanese Patent Laid-Open No. 2005-116739

  Thus, when the adhesive film for die bonding mounted on the back surface of the wafer was irradiated with a laser beam to melt the adhesive film, a part of the melted adhesive film was welded to the dicing tape, and the adhesive film was mounted. There is a problem that it is difficult to peel off the semiconductor chip from the dicing tape when picking up the semiconductor chip.

  The present invention has been made in view of the above-mentioned facts, and its main technical problem is to easily peel off an adhesive film for die bonding mounted on the back surface of a wafer divided into a plurality of chips from a dicing tape. It is an object of the present invention to provide a method for separating an adhesive film.

In order to solve the above main technical problem, according to the present invention, an adhesive film for die bonding is attached to the back surface of a wafer separated into a plurality of chips, and the adhesive film side of the wafer is attached to an annular frame. A method for separating an adhesive film that is attached to a surface of a dicing tape and that separates the adhesive film along divided grooves obtained by dividing the adhesive film into a plurality of chips,
Irradiating the adhesive film with a laser beam along the divided grooves, and an adhesive film fusing step of fusing the adhesive film along the divided grooves;
The dicing tape side to which the adhesive film attached to the back surface of the wafer subjected to the adhesive film fusing step is stuck is held on a spinner table, and a solvent for dissolving the adhesive film is provided at the center of the wafer. By rotating the spinner table while dripping, the solvent is allowed to act on a part of the melted and resolidified adhesive film remaining along the dividing groove, and the part of the melted and resolidified adhesive film is dissolved. A dissolution step,
A method for separating an adhesive film is provided.

Further, according to the present invention, an adhesive film for die bonding is formed on the back surface of a wafer in which a plurality of streets are formed in a lattice shape on the surface and devices are formed in a plurality of regions partitioned by the plurality of streets. A method for separating an adhesive film, wherein the adhesive film side of the wafer is attached to a surface of a dicing tape attached to an annular frame, and the adhesive film is separated along the streets.
An adhesive film fusing step of irradiating a laser beam along the street from the surface side of the wafer to form a dividing groove in the wafer and fusing the adhesive film;
The dicing tape side to which the adhesive film attached to the back surface of the wafer subjected to the adhesive film fusing step is stuck is held on a spinner table, and a solvent for dissolving the adhesive film is provided at the center of the wafer. By rotating the spinner table while dripping, the solvent is allowed to act on a part of the melted and resolidified adhesive film remaining along the dividing groove, and the part of the melted and resolidified adhesive film is dissolved. A dissolution step,
A method for separating an adhesive film is provided.

  According to the present invention, the adhesive film mounted on the back surface of the wafer is irradiated with a laser beam, and after performing the adhesive film fusing step of fusing the adhesive film along the divided grooves, the solvent that dissolves the adhesive film is divided into the divided grooves. The adhesive film is melted and re-solidified in the adhesive film fusing process, so that it acts on a part of the melt-re-solidified adhesive film remaining along the melt and re-melts part of the melt-solidified adhesive film. A part of the welded adhesive film is dissolved, and the weld between the adhesive film and the dicing tape is removed. Therefore, the chip having the adhesive film attached to the back surface can be easily peeled from the dicing tape.

  Hereinafter, preferred embodiments of a method for separating an adhesive film according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 shows a perspective view of a semiconductor wafer divided into a plurality of semiconductor chips. A semiconductor wafer 10 shown in FIG. 1 is made of, for example, a silicon wafer having a thickness of 600 μm. A plurality of streets 101 are formed in a lattice shape on the surface 10 a and a plurality of regions partitioned by the plurality of streets 101. A device 102 is formed. A procedure for dividing the semiconductor wafer 10 into individual semiconductor chips by the prior dicing method will be described.

  In order to divide the semiconductor wafer 10 into individual semiconductor chips by the tip dicing method, first, a predetermined depth (a depth corresponding to the finished thickness of each semiconductor chip) is formed along the street 101 formed on the surface 10a of the semiconductor wafer 10. ) Is formed (divided groove forming step). In this dividing groove forming step, a cutting device 2 generally used as a dicing device can be used as shown in FIG. In other words, the cutting device 2 includes a chuck table 21 having a suction holding unit and a cutting unit 23 having a cutting blade 22. By holding the surface 10a of the semiconductor wafer 2 on the chuck table 21 of the cutting apparatus 2 and rotating the cutting blade 22 of the cutting means 23 and cutting and feeding the chuck table 21 in the direction indicated by the arrow X, A dividing groove 103 is formed along a street 101 extending in a predetermined direction. The dividing groove 103 is set to a depth (for example, 110 μm) corresponding to the finished thickness of each semiconductor chip to be divided as shown in FIG. When the dividing groove 103 is formed along the street 101 extending in a predetermined direction as described above, the cutting means 23 is indexed and fed in the direction indicated by the arrow Y by the interval of the street 101, and the cutting feed is performed again. Then, if the cutting feed and the index feed are performed for all the streets 101 extending in a predetermined direction, the chuck table 21 is rotated by 90 degrees so that each street 101 extending at a right angle to the predetermined direction. The dividing groove 103 is formed along all the streets 101 formed in the semiconductor wafer 10 by executing the cutting feed and the indexing feed along.

  When the dividing groove 103 having a predetermined depth is formed along the street 101 on the surface 10a of the semiconductor wafer 10 by the above-described dividing groove forming step, the semiconductor wafer 10 is formed as shown in FIGS. 3 (a) and 3 (b). The protective member 3 for grinding is stuck on the surface 10a (surface on which the device 102 is formed) (protective member sticking step). In the illustrated embodiment, the protective member 3 is a polyolefin sheet having a thickness of 150 μm.

  Next, the back surface 10b of the semiconductor wafer 10 having the protective member 3 attached to the front surface is ground, and the divided grooves 103 are exposed on the back surface 10b and divided into individual semiconductor chips (divided groove exposing step). This dividing groove exposing step is performed by a grinding apparatus 4 including a grinding means 43 having a chuck table 41 and a grinding wheel 42 as shown in FIG. That is, the semiconductor wafer 10 is held on the chuck table 41 with the back surface 10b facing up. For example, while the chuck table 41 is rotated at 300 rpm, the grinding wheel 42 of the grinding means 43 is rotated at 6000 rpm, so that the back surface of the semiconductor wafer 10 is obtained. It grinds by contacting 10b, and grinds until the dividing groove 103 appears on the back surface 10b as shown in FIG. By grinding until the dividing grooves 103 are exposed in this way, the semiconductor wafer 10 is separated into individual semiconductor chips 100 as shown in FIG. In addition, since the protective member 3 is stuck on the surface of the separated semiconductor chips 100, the form of the semiconductor wafer 10 is maintained without being separated.

  If the semiconductor wafer 10 is separated into the individual semiconductor chips 100 by the above-described dicing method, an adhesive film attaching step for attaching an adhesive film for die bonding to the back surface 10b of the semiconductor wafer 10 separated into the individual semiconductor chips is performed. carry out. That is, as shown in FIGS. 5A and 5B, the adhesive film 5 is mounted on the back surface 10b of the semiconductor wafer 10 separated into individual semiconductor chips. At this time, the adhesive film 5 is pressed against the back surface 10b of the semiconductor wafer 10 while being heated at a temperature of 80 to 200 ° C. The adhesive film 5 is made of a film material having a thickness of 20 μm in which an epoxy resin and an acrylic resin are mixed.

  If the adhesive film mounting process is carried out as described above, the dicing tape sticking is performed so that the adhesive film 5 side of the semiconductor wafer 10 to which the adhesive film 5 is attached is attached to an extensible dicing tape attached to an annular frame. A landing process is performed. That is, as shown in FIGS. 6 (a) and 6 (b), the adhesive film 5 side of the semiconductor wafer 10 is placed on the surface 60a of the dicing tape 60 with the outer peripheral portion mounted so as to cover the inner opening of the annular frame 6. Affix. Accordingly, the protective member 3 attached to the surface of the semiconductor wafer 10 is on the upper side. The dicing tape 60 is formed of a polyolefin sheet having a thickness of 95 μm in the illustrated embodiment. In addition, as the dicing tape 60, a UV tape having a property that the adhesive force is reduced by an external stimulus such as ultraviolet rays is used.

Another embodiment of the above-described adhesive film attaching step and dicing tape attaching step will be described with reference to FIG.
The embodiment shown in FIG. 7 uses a dicing tape with an adhesive film in which an adhesive film is bonded in advance to the surface of the dicing tape. That is, as shown in FIGS. 7A and 7B, the adhesive film 5 attached to the surface 60a of the dicing tape 60 with the outer peripheral portion mounted so as to cover the inner opening of the annular frame 6 is attached. The semiconductor wafer 10 separated into individual semiconductor chips 100 is mounted on the back surface 10b. At this time, the adhesive film 5 is pressed and attached to the back surface 10 b of the semiconductor wafer 10 while being heated at a temperature of 80 to 200 ° C. The dicing tape 60 is a polyolefin sheet having a thickness of 95 μm in the illustrated embodiment. As such a dicing tape with an adhesive film, a dicing tape with an adhesive film (LE5000) manufactured by Lintec Corporation can be used.

  If the adhesive film mounting process described above is performed, the adhesive film 5 mounted on the back surface 10b of the semiconductor wafer 10 separated into the individual semiconductor chips 100 is irradiated with a laser beam along the divided grooves 103 to form an adhesive film. An adhesive film breaking step of breaking 5 along the dividing groove 103 is performed. This adhesive film breaking step is performed by the laser processing apparatus 7 shown in FIG. The laser processing apparatus 7 shown in FIG. 8 has a chuck table 71 that holds a workpiece, laser beam irradiation means 72 that irradiates the workpiece held on the chuck table 71 with a laser beam, and a chuck table 71 that holds the workpiece. An image pickup means 73 for picking up the processed workpiece is provided. The chuck table 71 is configured to suck and hold a workpiece, and can be moved in a machining feed direction indicated by an arrow X and an index feed direction indicated by an arrow Y in FIG. Yes.

  The laser beam irradiation means 72 irradiates a pulsed laser beam from a condenser 722 attached to the tip of a cylindrical casing 721 arranged substantially horizontally. Further, the image pickup means 73 attached to the tip of the casing 721 constituting the laser beam irradiation means 72 is not a normal image pickup device (CCD) for picking up an image by visible light in the illustrated embodiment, but is applied to a workpiece. Infrared illuminating means for irradiating infrared light, an optical system for capturing the infrared light irradiated by the infrared illuminating means, an image pickup device (infrared CCD) for outputting an electrical signal corresponding to the infrared light captured by the optical system, and the like The captured image signal is sent to the control means described later.

The adhesive film fusing process performed using the laser processing apparatus 7 described above will be described with reference to FIGS.
First, as shown in FIG. 8, the adhesive film fusing step chucks the protective member 3 side attached to the surface of the semiconductor wafer 10 (the back side is attached to the surface of the dicing tape 60 via the adhesive film 5). It is placed on the table 71 and held by suction. Therefore, the dicing tape 60 to which the adhesive film 5 attached to the back surface 10b of the semiconductor wafer 10 is attached is on the upper side. In FIG. 8, the annular frame 6 to which the dicing tape 60 is mounted is omitted, but the annular frame 6 is held by an appropriate frame holding means provided on the chuck table 71.

  As described above, the chuck table 71 that sucks and holds the semiconductor wafer 10 is positioned directly below the imaging means 73 by a moving mechanism (not shown). When the chuck table 71 is positioned immediately below the image pickup means 73, an alignment operation for detecting a processing region to be laser processed of the adhesive film 5 mounted on the back surface 10b of the semiconductor wafer 10 is executed by the image pickup means 73 and a control means (not shown). To do. That is, the imaging means 73 and the control means align the division grooves 103 formed in a predetermined direction of the semiconductor wafer 10 with the condenser 722 of the laser beam irradiation means 71 that irradiates a laser beam along the division grooves 103. Image processing such as pattern matching is performed to perform the laser beam irradiation position alignment. In addition, alignment of the laser beam irradiation position is similarly performed on the divided grooves 103 formed in the direction perpendicular to the predetermined direction formed in the semiconductor wafer 10. At this time, when the adhesive film 5 and the dicing tape 60 mounted on the back surface 10b of the semiconductor wafer 10 separated into individual semiconductor chips are non-transparent and the dividing groove 103 cannot be confirmed, infrared imaging means 73 is used as the imaging means 73. By using an optical system that captures infrared light and an image sensor (infrared CCD) that outputs an electrical signal corresponding to the infrared light, the dividing groove 103 can be imaged through the adhesive film 5 and the dicing tape 60.

  When the alignment of the laser beam irradiation position is performed as described above, the chuck table 71 is moved to the laser beam irradiation region where the condenser 722 of the laser beam irradiation means 72 for irradiating the laser beam is positioned, as shown in FIG. One end (the left end in FIG. 9) of the predetermined dividing groove 103 is positioned directly below the condenser 722 of the laser beam irradiation means 72. The dicing tape 60 does not absorb the laser light from the condenser 722, but the adhesive film 5 irradiates the laser beam having a wavelength that absorbs the laser light while the chuck table 71, that is, the semiconductor wafer 10 is moved in the direction indicated by the arrow X1 in FIG. When the other end (right end in FIG. 9) of the dividing groove 103 reaches the irradiation position of the condenser 722, the irradiation with the pulse laser beam is stopped and the chuck table 71, that is, the semiconductor wafer 10 is moved. Stop. At this time, the pulsed laser beam emitted from the condenser 722 of the laser beam application means 72 has a condensing point P (a point where a condensing spot diameter is formed) aligned with the upper surface of the adhesive film 5 in the illustrated embodiment. Irradiated. The wavelength of the laser beam is set to 355 nm which is not absorbed by the polyolefin sheet constituting the dicing tape 60 but absorbed by the film material mixed with the epoxy resin and the acrylic resin constituting the adhesive film 5. However, it is appropriately set depending on the relationship between the material selected as the dicing tape and the material selected as the adhesive film. As a result, as shown in FIG. 10, the adhesive film 5 is melted along the dividing grooves 103 by the energy of the laser beam transmitted through the dicing tape 60, but a part 51 of the melted and re-solidified adhesive film is formed on the dicing tape 60. Welding.

In addition, the processing conditions in the said adhesive film fusing process are set as follows, for example.
Type of laser beam: Solid laser (YVO4 laser, YAG laser)
Wavelength: 355nm
Condensing spot diameter: φ9.2μm
Repetition frequency: 50 kHz
Average output: 0.5W
Processing feed rate: 500 mm / sec

  As described above, when the adhesive film 5 is melted along the divided grooves 103 in a predetermined direction, the chuck table 71 is indexed and fed by the interval of the divided grooves 103 in the direction indicated by the arrow Y (see FIG. 8), and the above processing is performed again. Carry out feeding. If the machining feed and the index feed are performed along all the divided grooves 103 formed in the predetermined direction, the chuck table 71 is rotated 90 degrees and formed perpendicular to the predetermined direction. By performing the processing feed and the index feed along the divided grooves 103, the adhesive film 5 is fused to the adhesive film 5 a attached to each semiconductor chip 100 in which the semiconductor wafer 10 is separated by the divided grooves 103. In the adhesive film 5a melted in this way, a part 51 of the adhesive film melted and re-solidified as described above is welded to the dicing tape 60.

Next, another embodiment of the adhesive film fusing process will be described with reference to FIGS. 11 to 13.
In this embodiment, if the adhesive film attaching step and the dicing tape attaching step shown in FIGS. 5, 6, and 7 are performed, they are attached to the surface of the semiconductor wafer 10 as shown in FIG. 11. The protective member 3 is peeled off (protective member peeling step). With the protective member 3 peeled in this way, the adhesive film fusing step is performed. This adhesive film fusing step can be performed using the laser processing apparatus 7 shown in FIG. That is, as shown in FIG. 12, the dicing tape 60 side of the semiconductor wafer 10 adhered to the surface of the dicing tape 60 via the adhesive film 5 is placed on the chuck table 71 and sucked and held. Accordingly, the surface 10a of the semiconductor wafer 10 is on the upper side. In FIG. 12, the annular frame 6 on which the dicing tape 60 is mounted is omitted, but the annular frame 6 is held by an appropriate frame holding means provided on the chuck table 71.

  If the semiconductor wafer 10 is held on the chuck table 71 as described above, the alignment operation described above is performed. Then, as shown in FIG. 12, the chuck table 71 is moved to the laser beam irradiation region where the condenser 722 of the laser beam irradiation means for irradiating the laser beam is located, and one end (the left end in FIG. 12) of the predetermined dividing groove 103 is condensed. It is positioned directly below the vessel 722. Then, while irradiating the adhesive film 5 with a pulse laser beam from the condenser 722 through the divided grooves 103 formed in the semiconductor wafer 10, the chuck table 71, that is, the semiconductor wafer 10 is moved at a predetermined feed rate in the direction indicated by the arrow X1 in FIG. When the other end (right end in FIG. 12) of the dividing groove 103 reaches the irradiation position of the condenser 722, the irradiation of the pulse laser beam is stopped and the movement of the chuck table 71, that is, the semiconductor wafer 10 is stopped. At this time, the pulsed laser beam emitted from the condenser 722 of the laser beam application means 72 has a condensing point P (a point where a condensing spot diameter is formed) aligned with the upper surface of the adhesive film 5 in the illustrated embodiment. Irradiated. The wavelength of the laser beam is set to 355 nm which is not absorbed by the polyolefin sheet constituting the dicing tape 60 but absorbed by the film material mixed with the epoxy resin and the acrylic resin constituting the adhesive film 5. However, it is appropriately set depending on the relationship between the material selected as the dicing tape and the material selected as the adhesive film. As a result, as shown in FIG. 13, the adhesive film 5 is melted and cut along the dividing grooves 103 by the energy of the laser beam, but the melted and resolidified part 51 is welded to the dicing tape 60. In this way, by performing the adhesive film fusing step along all the divided grooves 103 formed in the semiconductor wafer 10, the adhesive film 5 is provided for each semiconductor chip 100 in which the semiconductor wafer 10 is separated by the divided grooves 103. Fusing to the adhesive film 5a attached to the. In the adhesive film 5a melted in this way, a part 51 of the adhesive film melted and re-solidified as described above is welded to the dicing tape 60.

Next, still another embodiment of the adhesive film fusing process will be described with reference to FIGS.
In this embodiment, the laser processing apparatus 7 is used to form split grooves along the streets 101 of the semiconductor wafer 10 shown in FIG. 1, and the adhesive film 5 mounted on the back surface 10b of the semiconductor wafer is split into the split grooves. At the same time, an adhesive film fusing process is performed. In this embodiment, as shown in FIG. 14, the adhesive film 5 attached to the front surface 60 a of the dicing tape 60 with the outer peripheral portion attached so as to cover the inner opening of the annular frame 6 is attached to the back surface of the semiconductor wafer 10. It attaches to 10b (adhesive film attachment process).

  When the adhesive film mounting step is performed as described above, the dicing tape 60 side of the semiconductor wafer 10 (the back surface is attached to the surface of the dicing tape 60 via the adhesive film 5) as shown in FIG. It is placed on the chuck table 71 and held by suction. Accordingly, the surface 10a of the semiconductor wafer 10 is on the upper side. In FIG. 12, the annular frame 6 on which the dicing tape 60 is mounted is omitted, but the annular frame 6 is held by an appropriate frame holding means provided on the chuck table 71.

  If the semiconductor wafer 10 is held on the chuck table 71 as described above, the alignment operation described above is performed. Then, as shown in FIG. 15, the chuck table 71 is moved to the laser beam irradiation region where the condenser 722 of the laser beam irradiating means for irradiating the laser beam, and one end (the left end in FIG. 15) of the predetermined street 101 is connected to the condenser. It is positioned directly below 722. Then, while irradiating the street 101 formed on the semiconductor wafer 10 with a pulse laser beam from the condenser 722, the chuck table 71, that is, the semiconductor wafer 10 is moved at a predetermined feed speed in the direction indicated by the arrow X 1 in FIG. When the other end (right end in FIG. 15) reaches the irradiation position of the condenser 722, the irradiation of the pulse laser beam is stopped and the movement of the chuck table 71, that is, the semiconductor wafer 10 is stopped. At this time, the pulsed laser beam emitted from the condenser 722 of the laser beam application means 72 has a condensing point P (a point where a condensing spot diameter is formed) as the surface 10a (upper surface) of the semiconductor wafer 10 in the illustrated embodiment. ). As a result, as shown in FIG. 16, the semiconductor wafer 10 is formed with the divided grooves 103 made of the laser processed grooves along the streets 101, and the adhesive film 5 is melted along the divided grooves 103. In the adhesive film 5 thus melted, a part 51 of the adhesive film melted and re-solidified is welded to the dicing tape 60.

In addition, the processing conditions in the said adhesive film fusing process are set as follows, for example.
Type of laser beam: Solid laser (YVO4 laser, YAG laser)
Wavelength: 355nm
Condensing spot diameter: φ9.2μm
Repetition frequency: 50 kHz
Average output: 3W
Processing feed rate: 200 mm / sec

  As described above, by performing the adhesive film fusing process along all the streets 101 formed on the semiconductor wafer 10, the semiconductor wafer 10 is divided into individual semiconductor chips 100 along the streets 101. In addition, as for the adhesive film 5a stuck for each semiconductor chip 100, the part 51 melted and re-solidified as described above is welded to the dicing tape 60.

  The adhesive film 5 that has been subjected to the adhesive film fusing process as described above is melted along the divided grooves 103, but a part of the melted and re-solidified material is welded to the dicing tape 60. Parts need to be removed. Therefore, in the present invention, an adhesive film dissolving step is performed in which a solvent that dissolves the adhesive film is allowed to act on the melt-resolidified adhesive film remaining along the dividing grooves to dissolve the melt-solidified adhesive film. This adhesive film dissolving step is performed using the adhesive film dissolving apparatus shown in FIGS.

  The adhesive film dissolving apparatus 8 shown in FIGS. 17 to 19 includes a spinner table mechanism 81 and a solvent receiving means 82 disposed so as to surround the spinner table mechanism 81. The spinner table mechanism 81 includes a spinner table 811, an electric motor 812 that rotationally drives the spinner table 811, and a support mechanism 813 that supports the electric motor 812 movably in the vertical direction. The spinner table 811 includes a suction chuck 811a formed of a porous material, and the suction chuck 811a communicates with suction means (not shown). Accordingly, the spinner table 811 holds the wafer on the suction chuck 811a by placing a wafer as a workpiece on the suction chuck 811a and applying a negative pressure by suction means (not shown). The spinner table 811 is provided with a clamp 814 for fixing the annular frame 6. The electric motor 812 connects the spinner table 811 to the upper end of the drive shaft 812a. The support mechanism 813 includes a plurality of (three in the illustrated embodiment) support legs 813a and a plurality of (three in the illustrated embodiment) attached to the electric motor 812 by connecting the support legs 813a. ) Air cylinder 813b. The support mechanism 813 configured as described above operates the air cylinder 813b to move the electric motor 812 and the spinner table 811 to the workpiece loading / unloading position, which is the upper position illustrated in FIG. 18, and the lower position illustrated in FIG. Position to the working position that is the position.

  The solvent receiving means 82 includes a solvent receiving container 821, three supporting legs 822 (two are shown in FIG. 17) that support the solvent receiving container 821, and a drive shaft 812a of the electric motor 812. And a cover member 823 attached to the head. As shown in FIGS. 18 and 19, the solvent receiving container 821 includes a cylindrical outer wall 821a, a bottom wall 821b, and an inner wall 821c. A hole 821d through which the drive shaft 812a of the electric motor 812 is inserted is provided at the center of the bottom wall 821b, and an inner wall 821c protruding upward from the periphery of the hole 821d is formed. As shown in FIG. 17, the bottom wall 821b is provided with a drain port 821e, and a drain hose 824 is connected to the drain port 821e. The cover member 823 is formed in a disc shape and includes a cover portion 823a protruding downward from the outer peripheral edge thereof. When the electric motor 812 and the spinner table 811 are positioned at the work position shown in FIG. 19, the cover member 823 configured as described above has a gap on the outer side of the inner wall 821 c that constitutes the cleaning water receiving container 821. Is positioned to polymerize.

  The illustrated adhesive film dissolving apparatus 8 includes a solvent supply means 84 for supplying a solvent for dissolving the adhesive film 5 to the surface of a semiconductor wafer, which is a workpiece, held on the spinner table 811. The solvent supply means 84 applies the solvent toward the surface of the semiconductor wafer 10 held on the spinner table 811 (attached to the surface of the dicing tape 60 attached to the annular frame 6 via the adhesive film 5). A solvent supply nozzle 841 to be supplied and an electric motor 812 that can be rotated forward and backward to swing the solvent supply nozzle 841 are provided. The solvent supply nozzle 841 is connected to a solvent supply source (not shown). The solvent supply nozzle 841 includes a nozzle portion 841a that extends horizontally and has a distal end bent downward, and a support portion 841b that extends downward from the base end of the nozzle portion 841a. The support portion 841b is the solvent receiving container. An insertion hole (not shown) provided in the bottom wall 821b constituting the 821 is inserted and connected to a liquid resin liquid supply source (not shown). In addition, a seal member (not shown) that seals between the support portion 841b and the support hole 841b is attached to the periphery of the insertion hole (not shown) through which the support portion 841b of the solvent supply nozzle 841 is inserted.

  The illustrated adhesive film dissolving apparatus 8 includes cleaning water supply means 85 for cleaning the semiconductor wafer 10 held on the spinner table 811. The cleaning water supply means 85 includes a cleaning water nozzle 851 that ejects cleaning water toward the semiconductor wafer held by the spinner table 811, and an electric motor (not shown) that can rotate forward and reverse to swing the cleaning water nozzle 851. The cleaning water nozzle 851 is connected to a cleaning water supply source (not shown). The washing water nozzle 851 includes a nozzle portion 851a that extends horizontally and has a distal end bent downward, and a support portion 851b that extends downward from the base end of the nozzle portion 851a. The support portion 851b is the solvent receiving container. An insertion hole (not shown) provided in the bottom wall 821b constituting 821 is inserted and connected to a cleaning water supply source (not shown). A seal member (not shown) that seals between the support portion 851b and the support hole 851b is attached to the periphery of an insertion hole (not shown) through which the support portion 851b of the cleaning water nozzle 851 is inserted.

  The illustrated adhesive film dissolving apparatus 8 includes an air supply means 86 for blowing air to the semiconductor wafer 10 held on the spinner table 811. The air supply means 86 includes an air nozzle 861 that ejects air toward the semiconductor wafer 10 held by the spinner table 811, and an electric motor 862 that can be rotated forward and backward to swing the air nozzle 861. The air nozzle 861 is connected to an air supply source (not shown). The air nozzle 861 includes a horizontally extending nozzle portion 861a and a support portion 861b extending downward from the base end of the nozzle portion 861a. The support portion 861b is provided on the bottom wall 821b constituting the solvent receiving container 821. The insertion hole (not shown) is inserted and connected to an air supply source (not shown). A seal member (not shown) that seals between the support portion 861b is mounted on the periphery of an insertion hole (not shown) through which the support portion 861b of the air nozzle 861 is inserted.

Next, an adhesive film dissolving step performed using the above-described adhesive film dissolving apparatus 8 will be described.
The semiconductor wafer 10 (adhered to the surface of the dicing tape 60 attached to the annular frame 6) on which the adhesive film fusing step described above has been performed is a spinner that constitutes the adhesive film dissolving device 8 by a transport device (not shown). It is conveyed onto the suction chuck 811a of the table 811 and sucked and held by the suction chuck 811a (wafer holding step). The annular frame 60 is fixed by a clamp 814. At this time, the spinner table 811 is positioned at the workpiece loading / unloading position shown in FIG. 18, and the solvent supply nozzle 841, cleaning water nozzle 851 and air nozzle 861 are spinner table 811 as shown in FIGS. Is positioned at a standby position separated from above.

  If the wafer holding step of holding the semiconductor wafer 10 on which the adhesive film fusing step has been performed on the spinner table 811 of the adhesive film melting device 8 is executed, the spinner table 811 is positioned at the working position shown in FIG. The nozzle 841 is positioned at the center of the semiconductor wafer 10 held on the spinner table 811. Then, a solvent for dissolving the adhesive film 5, for example, ethanol, is dropped from the solvent supply nozzle 841, and the spinner table 811 is rotated at a rotation speed of 10 rpm. Therefore, as shown in FIG. 20A, ethanol 80 acts on a part 51 of the adhesive film 5 melted and re-solidified through the dividing groove 103 formed in the semiconductor wafer 10. As a result, as shown in FIG. 20B, the melted and re-solidified part 51 of the adhesive film 5 is dissolved, and the adhesion between the adhesive film 5 and the dicing tape 60 is removed (adhesive film dissolving step). What is necessary is just to implement this adhesive film melt | dissolution process for about 5 minutes. As the solvent, methanol, isopropyl alcohol, acetone or the like can be used. In the adhesive film dissolving step, a solvent may be applied to a part 51 of the adhesive film 5 melted and re-solidified through the dividing grooves 103 formed in the semiconductor wafer 10 and left for about 5 minutes.

  If the adhesive film dissolution process described above is performed, a cleaning process is performed. In other words, an electric motor (not shown) is driven to position the nozzle outlet 851 a of the cleaning water supply nozzle 851 above the center of the semiconductor wafer 10 held on the spinner table 811. Then, while rotating the spinner table 811 at a rotation speed of, for example, 800 rpm, cleaning water composed of pure water and air is ejected from the ejection port of the nozzle portion 851a. That is, the nozzle portion 851a is a so-called two-fluid nozzle and is supplied with pure water of about 0.2 MPa, and is supplied with air of about 0.3 to 0.5 MPa, and the pure water is ejected by the pressure of the air. The surface of the semiconductor wafer 10 is cleaned. At this time, from the position where the electric motor (not shown) is driven and the cleaning water ejected from the nozzle 851a of the cleaning water supply nozzle 851 hits the center of the semiconductor wafer 10 held by the spinner table 811 to the position hitting the outer periphery. It is desirable to swing within the required angle range.

  When the above-described cleaning process is completed, a drying process is performed. That is, the spinner table 711 is rotated at a rotational speed of, for example, 2000 rpm for about 20 seconds, and the wafer is jetted from the air nozzle 861 to the semiconductor wafer 10.

  If the adhesive film dissolving step, the cleaning step, and the drying step are executed, a pickup step for picking up the semiconductor chip 100 to which the adhesive film 5a is attached from the dicing tape 60 attached to the annular frame 6 is executed. To do. This pickup process is performed by the pickup device 9 shown in FIGS. The pick-up device 9 shown in the figure is mounted on the annular frame 6 concentrically disposed within the base 91 and a cylindrical base 91 on which a placement surface 911 on which the annular frame 6 is placed is formed. An expansion means 92 for expanding the dicing tape 60 is provided. The expansion means 92 includes a cylindrical expansion member 921 that supports a region 61 where a plurality of semiconductor chips 100 are present in the dicing tape 60. The expansion member 921 is moved vertically between the reference position shown in (a) of FIG. 22 and the extended position shown in (b) of FIG. 22 above the reference position by lifting means (not shown). It is configured to be movable in the axial direction. In the illustrated embodiment, an ultraviolet irradiation lamp 93 is disposed in the expansion member 921.

A pickup process performed using the pickup device 8 described above will be described with reference to FIGS. 21 and 22.
As described above, a plurality of semiconductor chips 100 supported on the upper surface of the expandable dicing tape 60 mounted on the annular frame 6 (the adhesive film 5a mounted on the back surface is attached to the upper surface of the dicing tape 60). As shown in FIG. 21 and FIG. 22A, the annular frame 6 is placed on the placement surface 911 of the cylindrical base 91 and is fixed to the base 91 by the clamp 94. Next, as shown in FIG. 22B, the expansion member 921 of the expansion means 92 that supports the region 61 where the plurality of semiconductor chips 100 are present in the dicing tape 60 is lifted by a lifting means (not shown). Is moved from the reference position to the extended position shown in FIG. As a result, the dicing tape 60 that can be expanded is expanded, so that the adhesive film 5a is attached to the dicing tape 60 and the adhesive film 5a that is attached to the semiconductor chip 100. Thus, the semiconductor chip 100 can be easily detached from the dicing tape 60, and a gap is formed between each semiconductor chip 100 and the adhesive film 5a attached to the semiconductor chip 100.

  Next, as shown in FIG. 21, the pick-up collet 90 disposed above the pick-up device 9 is operated to separate the individual semiconductor chips 100 from the upper surface of the dicing tape 60 and transport them to a tray (not shown). At this time, the ultraviolet irradiation lamp 93 provided in the expansion member 921 is turned on to irradiate the dicing tape 60 with ultraviolet rays, and the adhesive strength of the dicing tape 60 is reduced, so that it can be detached more easily. In this pickup process, the part 51 melted and re-solidified of the adhesive film 5 is dissolved by carrying out the adhesive film dissolving process, and the adhesion between the adhesive film 5 and the dicing tape 60 is removed. The semiconductor chip 100 to which the adhesive film 5a is attached can be easily peeled from the dicing tape 60. Thus, the semiconductor chip 100 detached from the dicing tape 60 is in a state where the adhesive film 5a is attached to the back surface as shown in FIG. 23, and the semiconductor chip 100 having the adhesive film 5a attached to the back surface is obtained. It is done.

The perspective view of the semiconductor wafer divided | segmented into each semiconductor chip. Explanatory drawing of the dividing-slot formation process in the tip dicing method which divides | segments a semiconductor wafer into each chip | tip. Explanatory drawing of the protection member sticking process in the tip dicing method which divides | segments a semiconductor wafer into each chip | tip. Explanatory drawing of the division | segmentation groove | channel exposure process in the tip dicing method which divides | segments a semiconductor wafer into each chip | tip. Explanatory drawing of the adhesive film mounting process in the isolation | separation method of the adhesive film by this invention. Explanatory drawing of the dicing tape sticking process in the isolation | separation method of the adhesive film by this invention. Explanatory drawing which shows other embodiment of the adhesive film mounting process in the isolation | separation method of the adhesive film by this invention. The perspective view of the laser processing apparatus which implements the adhesive film fusing process in the isolation | separation method of the adhesive film by this invention. Explanatory drawing of the adhesive film fusing process in the isolation | separation method of the adhesive film by this invention. The principal part expanded sectional view which shows the state in which the adhesive film fusing process shown in FIG. 9 was implemented. Explanatory drawing of the protection member peeling process in the isolation | separation method of the adhesive film by this invention. Explanatory drawing which shows other embodiment of the adhesive film fusing process in the isolation | separation method of the adhesive film by this invention. The principal part expanded sectional view which shows the state in which the adhesive film fusing process shown in FIG. 12 was implemented. Explanatory drawing which shows other embodiment of the adhesive film mounting process in the isolation | separation method of the adhesive film by this invention. Explanatory drawing which shows other embodiment of the adhesive film fusing process in the isolation | separation method of the adhesive film by this invention. The principal part expanded sectional view which shows the state in which the adhesive film fusing process shown in FIG. 15 was implemented. The perspective view of the adhesive film melt | dissolution apparatus which implements the adhesive film melt | dissolution process in the isolation | separation method of the adhesive film by this invention. Explanatory drawing which shows the state which located the spinner table of the adhesive film melt | dissolution apparatus shown in FIG. 17 in the workpiece carrying in / out position. Explanatory drawing which shows the state which located the spinner table of the adhesive film melt | dissolution apparatus shown in FIG. 2 in the working position. The principal part expanded sectional view which shows the state by which the adhesive film melt | dissolution process was implemented with the adhesive film melt | dissolution apparatus shown in FIG. The perspective view of the pick-up apparatus which implements the pick-up process which picks up the semiconductor chip with which the adhesive film was mounted | worn on the back surface. Explanatory drawing of the pick-up process implemented using the pick-up apparatus shown in FIG. The perspective view of the semiconductor chip picked up by the pick-up process shown in FIG.

Explanation of symbols

2: Cutting device 21: Chuck table 22 of cutting device: Cutting blade 23: Cutting means 3: Protection member 4: Grinding device 41: Chuck table 42 of grinding device Grinding wheel:
43: Grinding means 5: Adhesive film 6: Ring frame 60: Dicing tape 7: Laser processing device 71: Chuck table 72 of laser processing device 72: Laser beam irradiation means 722: Concentrator 73: Imaging means 8: Adhesive film dissolving device 81: Spinner table mechanism 811: Spinner table 82: Solvent receiving means 84: Solvent supply means 841: Solvent supply nozzle 85: Wash water supply means 851: Wash water nozzle 86: Air supply means 861: Air nozzle 9: Pickup device 90: Pickup collet 91: cylindrical base 92: expansion means 93: expansion means 10: semiconductor wafer 100: semiconductor chip 101: street 102: device 103: dividing groove

Claims (2)

An adhesive film for die bonding is attached to the back surface of the wafer separated into a plurality of chips, and the adhesive film side of the wafer is attached to the surface of a dicing tape attached to an annular frame. A method for separating an adhesive film that separates along the divided grooves divided into the plurality of chips,
Irradiating the adhesive film with a laser beam along the divided grooves, and an adhesive film fusing step of fusing the adhesive film along the divided grooves;
The dicing tape side to which the adhesive film attached to the back surface of the wafer subjected to the adhesive film fusing step is stuck is held on a spinner table, and a solvent for dissolving the adhesive film is provided at the center of the wafer. By rotating the spinner table while dripping, the solvent is allowed to act on a part of the melted and resolidified adhesive film remaining along the dividing groove, and the part of the melted and resolidified adhesive film is dissolved. A dissolution step,
A method for separating an adhesive film. A plurality of streets are formed in a lattice pattern on the front surface and a device is formed in a plurality of regions partitioned by the plurality of streets. A die bonding adhesive film is attached to the back surface of the wafer, and the wafer is bonded. The film side is attached to the surface of a dicing tape attached to an annular frame, and is a method for separating an adhesive film that separates the adhesive film along the street,
An adhesive film fusing step of irradiating a laser beam along the street from the surface side of the wafer to form a dividing groove in the wafer and fusing the adhesive film;
The dicing tape side to which the adhesive film attached to the back surface of the wafer subjected to the adhesive film fusing step is stuck is held on a spinner table, and a solvent for dissolving the adhesive film is provided at the center of the wafer. By rotating the spinner table while dripping, the solvent is allowed to act on a part of the melted and resolidified adhesive film remaining along the dividing groove, and the part of the melted and resolidified adhesive film is dissolved. A dissolution step,
A method for separating an adhesive film.

Images