TWI683358B - Manufacturing method of semiconductor device - Google Patents

Abstract

The manufacturing method of the semiconductor device of the present invention includes: forming a groove from the front side of the semiconductor wafer, or a processing step before forming a modified region on the semiconductor wafer, and polishing the semiconductor wafer from the back side, along the groove or the modified The wafer singulation step of singulation of the semiconductor wafer into a plurality of wafers, and the thermosetting protection of the thin film for forming a protective film with a support provided with a thin film for forming a thermosetting protective film on the support The step of attaching the film-forming film side to the back surface of the singulated semiconductor wafer, and thermosetting the film for forming the thermosetting protective film attached to the semiconductor wafer to form a protective film After the thermal curing step and the thermal curing step, a pick-up step of picking up a wafer with a protective film on which the protective film is deposited on the wafer is stacked.

Description

Manufacturing method of semiconductor device

The present invention relates to a method for manufacturing a semiconductor device, and in particular to a method for manufacturing a semiconductor device in which a semiconductor wafer is singulated by a dicing before grinding (DBG) method and a protective film is formed on the back surface of the semiconductor wafer.

In the past, a prior dicing method in which dicing is performed in advance before back grinding to adjust the thickness of the wafer is well known. In the previous dicing method, for example, a cut-in groove was formed by cutting from the front surface of the wafer, and then the back surface was polished to at least reach the bottom surface of the cut-in groove, and then back-side polishing was performed to simultaneously adjust the thickness and divide the wafer of the semiconductor wafer.

The wafer divided by the previous dicing method is, for example, as disclosed in Patent Document 1, and it is known to form an adhesive layer (wafer bonding) for wafer fixing on the back surface of the wafer and then mount it.

At this time, specifically, first, a wafer divided into a plurality of wafers is attached on the adhesive film side of the composite film formed by bonding the adhesive film on the support. Then, by cutting the adhesive film along the wafer interval of the divided wafers, an adhesive layer formed by the adhesive film is formed on the back surface of each wafer. Back Each wafer on which the adhesive layer is formed is peeled off from the support after being picked up and mounted on a lead frame, a substrate, etc. to manufacture a semiconductor device.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Application Publication No. 2013-153071

In addition, in recent years, semiconductor devices have been manufactured by a mounting method called a flip-chip method. In this method, when mounting a semiconductor wafer having a circuit surface forming electrodes such as protrusions, the circuit surface side of the semiconductor wafer is bonded to a wafer mounting portion such as a lead frame. Therefore, the back side of the semiconductor wafer that does not form a circuit becomes an exposed structure. Therefore, in order to protect the semiconductor wafer on the back side of the semiconductor wafer, a protective film made of a hard organic material may be formed.

Here, the thin film used to form the protective film sometimes contains thermosetting resin. However, the film containing thermosetting resin may shrink during thermal curing, which may cause warpage of the wafer. The warpage of this wafer is particularly likely to occur when the singulated wafer has an elongated shape, and when the front surface of the wafer is coated with an organic film.

In view of the above problems, the present invention will provide a semiconductor wafer that is difficult to form even if a protective film is formed by thermal curing on the back surface of the wafer The manufacturing method of the warped semiconductor device is the subject of this case.

As a result of intensive studies, the inventors found that after thermosetting the thermosetting protective film forming film used to form the protective film, the above-mentioned problems can be solved by performing the pick-up step, and the present invention has been completed. That is, the present invention provides the following (1) to (7).

(1) A method of manufacturing a semiconductor device, comprising: forming a groove from the front side of the semiconductor wafer, or a processing step before forming a modified region on the semiconductor wafer, and polishing the semiconductor wafer from the back side, along The wafer singulation step of singulation of the semiconductor wafer into a plurality of wafers with the aforementioned grooves or modified regions and the formation of a protective film with a support provided with a thermosetting protective film forming film on the support The step of attaching the film side for forming the thermosetting protective film of the thin film to the back surface of the singulated semiconductor wafer and the film for forming the thermosetting protective film to be attached to the semiconductor wafer After the thermal curing, the thermal curing step of forming the protective film and the thermal curing step, the picking up step of picking up the wafer with the protective film on which the protective film is deposited on the wafer.

(2) The method for manufacturing a semiconductor device according to (1) above, wherein the support has a substrate, and the substrate has at least one layer selected from the group consisting of polyester films and polypropylene films Constituted film.

(3) The method for manufacturing a semiconductor device according to (1) or (2) above, further comprising a film or a protective film for forming a thermosetting protective film attached to the back surface of the semiconductor wafer, along the wafer gap The step of cutting and dividing into protective films in accordance with the shape of various wafers.

(4) The method for manufacturing a semiconductor device according to (3) above, wherein the step of dividing the protective film is performed between the thermal curing step and the picking step.

(5) The method for manufacturing a semiconductor device according to any one of (1) to (4) above, wherein the support-forming thin film for forming a protective film is held in a ring frame, and in this state, the foregoing The thin film for forming a thermosetting protective film is thermally cured to form a protective film.

(6) The method for manufacturing a semiconductor device according to any one of (1) to (5) above, wherein the front surface of the semiconductor wafer is covered with an organic film.

(7) The method of manufacturing a semiconductor device according to any one of (1) to (6) above, wherein the wafer has an elongated shape.

With the above manufacturing method of the present invention, even if the protective film is formed by thermal curing on the back surface of the wafer, it is difficult to warp the semiconductor wafer.

10‧‧‧Semiconductor wafer

11‧‧‧Ditch

11A‧‧‧Notch

12‧‧‧loop

13‧‧‧Organic film

15‧‧‧Semiconductor chip

16‧‧‧Back grinding tape

17‧‧‧Modified area

20‧‧‧ Thin film for forming protective film with support

21‧‧‧Support

21A‧‧‧Substrate

21B‧‧‧Adhesive layer

22‧‧‧ Thin film for forming thermosetting protective film

22A‧‧‧Protection film

23‧‧‧Adhesive layer for ring frame

24‧‧‧ Wafer with protective film

25‧‧‧ring frame

30‧‧‧Oven

[FIG. 1] In the manufacturing method of a semiconductor device, the front surface of a wafer A schematic cross-sectional view of the previous processing steps being grooved.

[Fig. 2] A schematic cross-sectional view showing a step of attaching a back grinding tape to the front surface of a wafer formed with grooves in the method of manufacturing a semiconductor device.

[FIG. 3] A schematic cross-sectional view showing a step of grinding a back surface of a wafer and singulating a semiconductor wafer in a method of manufacturing a semiconductor device.

[Fig. 4] A schematic cross-sectional view showing a step of attaching a support-forming film for forming a protective film to a singulated semiconductor wafer and a ring-shaped frame in a method of manufacturing a semiconductor device.

FIG. 5 is a schematic cross-sectional view showing a step of thermosetting a thin film for forming a thermosetting protective film in the method of manufacturing a semiconductor device.

[Fig. 6] A schematic cross-sectional view showing a step of dividing a protective film in a method of manufacturing a semiconductor device.

7 is a schematic cross-sectional view showing a step of picking up a wafer with a protective film in the method of manufacturing a semiconductor device.

[Fig. 8] A schematic cross-sectional view showing another example of a thin film for forming a protective film with a support.

[Fig. 9] A schematic cross-sectional view showing a method of manufacturing a semiconductor device in which a modified region is formed on a wafer to perform a previous processing step.

[Fig. 10] A schematic diagram showing a method of measuring the amount of wafer warpage.

[Forms for carrying out the invention]

Hereinafter, the method of manufacturing the semiconductor device according to the present invention will be described in more detail. And, in the following description, "weight The "average molecular weight (Mw)" is a value converted from polystyrene measured by column chromatography (GPC). Also, for example, "(meth)acrylate" means used as a term indicating both "acrylate" and "methacrylate", and the same applies to other similar terms.

The method for manufacturing a semiconductor device of the present invention includes the following steps (i) to (v).

(i) Forming grooves from the front side of the semiconductor wafer or processing steps before forming modified regions on the semiconductor wafer;

(ii) a wafer singulation step of grinding the semiconductor wafer from the back side and singulating the semiconductor wafer into a plurality of chips along the groove or the modified region;

(iii) The thermosetting protective film forming film side of the support-attached protective film forming film provided with the thermosetting protective film forming film on the support is attached to the singulated semiconductor crystal Attaching steps on the back of the circle;

(iv) The step of thermosetting the thin film for forming a thermosetting protective film attached to the semiconductor wafer to form a protective film; and

(v) After the thermal hardening step, the pick-up step of picking up the wafer with the protective film deposited on the wafer with the protective film

Furthermore, the method for manufacturing a semiconductor device of the present invention preferably further includes the following step (vi).

(vi) A thin film or protective film for forming a thermosetting protective film attached to the back surface of the semiconductor wafer, cut along the wafer interval, and divided into protective film division steps according to the shapes of various wafers.

Hereinafter, the method of manufacturing the semiconductor device according to the first embodiment of the present invention will be described in detail using FIGS. 1 to 7. 1 to 7 are diagrams showing in time series the method for manufacturing a semiconductor device according to the first embodiment of the present invention. Furthermore, in the first embodiment, grooves are formed during the pretreatment step.

[Pre-processing steps]

First, as shown in FIG. 1, a process step before forming the groove 11 from the front side of the semiconductor wafer 10 is performed. The groove 11 formed in this step is a groove with a thickness smaller than that of the wafer 10. The groove 11 can be formed using a conventionally known wafer dicing device or the like. In addition, the semiconductor wafer 10 is divided into a plurality of semiconductor wafers along the groove 11 in the wafer singulation step described later.

The semiconductor wafer 10 used in this embodiment may be a silicon wafer, or may be gallium. Arsenic and other wafers. The thickness of the semiconductor wafer 10 before polishing is not particularly limited, but it is usually about 500 to 1000 μm.

As shown in FIG. 1, the front surface of the semiconductor wafer 10 is preferably coated with an organic film 13. The organic film 13 is not particularly limited, and examples thereof include polyimide, oxazole, and silicone. Among these, polyimide is preferred. The semiconductor wafer 10 can protect the front surface by providing the organic film 13. Moreover, when the organic film 13 is provided on the semiconductor wafer 10, warpage tends to occur easily, so a large warpage suppression effect is required.

The semiconductor wafer 10 has a circuit 12 formed on its front surface. The formation of the circuit 12 on the front of the wafer can be widely used in the past by including etching methods and lift-off methods. Various methods to carry out.

[Wafer singulation step]

Next, the back grinding tape 16 is attached to the front surface of the wafer where the groove 11 is formed. After that, a wafer singulation step of grinding the back surface of the semiconductor wafer 10 and singulating the semiconductor wafer 10 into a plurality of semiconductor wafers 15 is performed. FIG. 2 shows a state where the back grinding tape 16 is attached to the front surface of the wafer where the groove 11 is formed.

Here, the back polishing tape 16 includes a substrate for back polishing tape and an adhesive layer for back polishing tape provided on the substrate, and is preferably attached to the semiconductor wafer 10 via the adhesive layer. The materials used for these back-grinding tape substrates and the adhesive layer for back-grinding tapes can be appropriately selected from well-known ones. For example, the adhesive layer for back-grinding tapes is made of an energy ray hardening type adhesive . By attaching the back grinding tape 16 on the front surface of the semiconductor wafer 10, the semiconductor wafer 10 will be singulated into a plurality of wafers 15 on one back grinding tape 16, so the singulated wafer 15 will not be shifted in position, etc. Can be handled in one piece. Moreover, when the back surface of the wafer 10 is polished, the circuit 12 can be protected. However, the attachment of the wafer to the back grinding tape 16 can be omitted.

The above-mentioned polishing of the semiconductor wafer is performed on the back surface of the semiconductor wafer 10 to at least reach the bottom of the groove 11. By this polishing, as shown in FIG. 3, the groove becomes a notch 11A penetrating through the wafer, and the semiconductor wafer 10 is divided by the notch 11A and singulated into individual semiconductor wafers 15.

The shape of the singulated semiconductor wafer 15 may also be square or Slender shape, but the slender shape is preferred. In the present invention, the warpage of the semiconductor wafer 15 having an elongated shape is more likely to occur, and there is a greater demand for the warpage suppression effect.

In the elongated shape, the wafer length is larger than the wafer width, and the ratio of the wafer length to the wafer width (aspect ratio) is preferably 2 or more, 4 or more, and 10 or more. The upper limit of the aspect ratio is not particularly limited, but it is usually about 100 or less, preferably 50 or less. The elongated semiconductor wafer 15 is preferably rectangular, and is not particularly limited. In addition, the thickness of the individualized wafer is not particularly limited, but it is usually about 10 to 300 μm, preferably 50 to 200 μm.

[Attaching steps]

Next, as shown in FIG. 4, an attaching step is performed, in which a thin film 20 for forming a protective film with a support is attached to the back surface of the semiconductor wafer 10 singulated into a plurality of wafers 15.

As shown in FIG. 4, the thin film 20 for forming a protective film with a support includes a support 21 and a thin film 22 for forming a thermosetting protective film provided on the support 21. The support 21 is not particularly limited as long as it can support the film 22 for forming the thermosetting protective film, but as shown in FIG. 4, it has a base 21A and a surface provided on one side of the base 21A The adhesive layer 21B and the film 22 for forming a thermosetting protective film are preferably attached to the adhesive layer 21B. The details of each member of the thin film 20 for forming a protective film with a support will be described later.

As shown in Fig. 4, the thin film for forming a protective film with a support The film 20 is formed by attaching the side of the thermosetting protective film forming film 22 to the back surface of the semiconductor wafer 10 singulated into a plurality of wafers 15. In addition, the thin film 20 for forming a protective film with a support is preferably provided with an attached ring frame 25 in an outer peripheral area surrounding the central area attached to the semiconductor wafer 10 (semiconductor wafer 15). With this, the thin film 20 for forming a protective film with a support and the plurality of semiconductor chips 15 attached thereon are integrally supported by the ring frame 25.

Thereafter, when the back grinding tape 16 is attached to the plurality of wafers 15, the back grinding tape 16 will peel off from the plurality of wafers 15 (semiconductor wafer 10 ). Moreover, when the adhesive layer for the back polishing tape 16 of the back polishing tape 16 is formed of an energy ray-curable adhesive, before peeling off the back polishing tape 16, the adhesive layer for the back polishing tape is irradiated with energy rays and hardened. good. In addition, as energy rays, ultraviolet rays, electron beams, etc. are generally used.

Here, in the plane direction, as shown in FIG. 4, the support 21 is preferably larger than the thin film 22 for forming a thermosetting protective film. The support 21 is provided with the thermosetting protective film forming film 22 on the central area by a large circle, and the peripheral area surrounding the central area becomes an area where the thermosetting protective film forming film 22 is not provided. It is easy to attach the outer peripheral area to the ring frame 25. Moreover, it is preferable that the support 21 is attached to the ring frame 25 via the adhesive layer 21B.

However, as shown in FIG. 8, the thin film 20 for forming a protective film with a support may be provided with an adhesive layer 23 for a ring frame on the thin film 22 for forming a thermosetting protective film. At this time, the thin film 22 for forming a thermosetting protective film is one circle larger than the semiconductor wafer 10, and the central region thereof will be attached There is a region of the semiconductor wafer 10, and at the same time, an adhesive layer 23 for a ring-shaped ring frame is provided around the center outer peripheral region. At this time, the thin film 20 for forming a protective film with a support is attached to the ring frame 25 via the ring frame adhesive layer 23.

The adhesive layer 23 for the ring frame is adhered by, for example, acrylic adhesives, rubber adhesives, silicone adhesives, urethane adhesives, polyester adhesives, polyvinyl ether adhesives, etc. Agent.

[Thermal hardening step]

After the above-mentioned attaching step, a thermosetting step is performed, which is to thermally harden the thin film 22 for forming a thermosetting protective film to form a protective film 22A.

The heat hardening step is performed in the oven 30, for example. That is, as shown in FIG. 5, it is preferable that the thin film 20 for forming a protective film with a support to which a plurality of semiconductor wafers 15 is attached is sent to the inside of the oven 30 as it is attached to the ring frame 25. The inside of the oven 30 is heated and thermally hardened. The heating in the oven 30 may be performed at a temperature and a heating time at which the film 22 for forming a thermosetting protective film can be cured. The temperature is preferably 70 to 175°C, and more preferably 80 to 150°C. The heating time is preferably 30 to 180 minutes, and more preferably 60 to 120 minutes.

[Protection step of protective film]

Thereafter, as shown in FIG. 6, a protective film division step is performed, which is to cut the protective film 22A attached to the back surface of the singulated semiconductor wafer 10 along the wafer interval and divide it into shapes corresponding to each wafer.

The semiconductor wafer 10 is singulated into wafers 15 by slits 11A, and the protective film 22A is cut along the slits 11A between the wafers 15. The cutting of the protective film 22A is performed by laser irradiation, cutting blade, expansion of the support 21, etc., but it is preferably performed by laser irradiation. When laser irradiation is performed, the laser light emitted from the laser light source 26 is irradiated from the front side of the semiconductor wafer 15 to the protective film 22A through the slit 11A. Thereby, the shape of the divided protective film 22A can easily correspond to the shape of the semiconductor wafer 15.

The cutting of the protective film 22A does not need to be performed until the protective film 22A is completely cut, and may also be partially cut, so that the protective film 22A can be separated at a later-described pick-up step, etc. Such a type is also included in the present invention In one type of protective film division step. In addition, in order to remove debris and the like generated when the protective film 22A is cut, after cutting the protective film 22A, the plurality of wafers 15 on the support 21 may be washed with a spinner or the like.

[Pickup step]

After the thermal curing step and the protective film dividing step, as shown in FIG. 7, the wafer 24 with a protective film formed by stacking the protective film 22A on each semiconductor wafer 15 is picked up, and then peeled off from the support 21. In order to make the support 21 easy to pick up, it can also be extended to the plane direction before picking up. The wafer 24 with a protective film peeled off from the support 21 can be bonded to a wafer mounting portion such as a lead frame by a method called a flip-chip method to obtain a semiconductor device.

[Second Embodiment]

Next, a method of manufacturing a semiconductor device according to the second embodiment of the present invention will be described in detail. In the first embodiment, in the pretreatment step, the groove is cut and provided to be singulated, but in the second embodiment, the modified region is formed instead of the groove. Hereinafter, with respect to the second embodiment, differences from the first embodiment will be described. In addition, the configuration and steps of which the description is omitted are the same as in the first embodiment.

In this embodiment, as shown in FIG. 9, first, a pre-processing step is performed, which forms a modified region 17 on the semiconductor wafer 10. The modified region 17 is a portion of the semiconductor wafer 10 that has been embrittled. By polishing in the polishing step, the semiconductor wafer 10 will be thinned, and by adding the force applied by the polishing, the semiconductor wafer 10 will be The destruction becomes the starting point of the singulation of the semiconductor wafer. The formation of the modified region 17 can be performed by laser irradiation with a focus on the inside of the semiconductor wafer 10. Laser irradiation can also be performed from the front side of the semiconductor wafer 10 or from the back side.

In addition, the front surface of the semiconductor wafer 10 is the same as the first embodiment, and the organic film 13 is preferably coated. In addition, the semiconductor wafer 10 is the same as the first embodiment, and a circuit 12 is formed on the front surface thereof.

In addition, the illustrations showing the steps other than the processing before the description below are the same as those in the first embodiment, so they are omitted, but the notch 11A shown in FIGS.

Next, a back grinding tape 16 is attached to the front surface of the wafer where the modified region 17 is formed. However, in this embodiment, the backside research can also be omitted Abrasive tape 16 is attached. After that, the back surface of the semiconductor wafer 10 is polished and singulated into plural chips along the modified region 17.

Here, by polishing, the polished surface (wafer back surface) only needs to reach the modified region 17, and it is not necessary to reach the modified region 17 meticulously. Specifically, the modified region 17 is set as the starting point, and it is polished to close to the modified The position of the region 17 is such that the semiconductor wafer 10 is destroyed and singulated into the semiconductor wafer 15.

Thereafter, as in the first embodiment, the attaching step and the thermosetting step are performed, and the protective film dividing step and the picking step are further performed. However, in this embodiment, it is preferable that the protective film division step divides the protective film by expanding the support 21. At this time, depending on the properties of the protective film 22A, the support 21 may be expanded while heating or cooling the protective film 22A.

In addition, in the above first and second embodiments, the protective film dividing step is performed between the thermal curing step and the picking step, and the protective film dividing step may also be performed between the attaching step and the thermal curing step. When the protective film dividing step is performed between the attaching step and the thermosetting step, in the protective film dividing step, the thermosetting protective film forming film 22 before thermosetting is cut and then divided. The other steps are the same as above, so the description is omitted.

Furthermore, the thin film 22 for forming a thermosetting protective film or the protective film 22A may be laser marked. Laser marking is a method of irradiating laser light and marking by cutting the front surface of the thin film 22 for forming a thermosetting protective film or the protective film 22A. The laser marking may also be performed after the thin film 22 for forming a thermosetting protective film is attached to the semiconductor wafer 15, after the thermosetting step It is better to perform, more preferably between the heat hardening step and the picking step.

In addition, the laser mark is usually irradiated by irradiating the laser light from the support 21 side through the support 21 on the front surface of the protective film 22A or the protective film forming film 22.

In the above method of manufacturing a semiconductor device, in order to perform the pick-up step after the thermosetting step, the thin film 22 for forming a thermosetting protective film is thermally cured in a state supported by the support 21. Therefore, the thin film 22 for forming a thermosetting protective film hardly shrinks due to heat curing and becomes a cured product, so the semiconductor wafer 15 is less likely to be warped. Furthermore, in the present invention, by adopting the previous dicing method, during back-grinding, the wafer is divided at the time when the wafer becomes thin, so it is easy to prevent the warpage of the wafer, thereby also easily preventing the warpage of each semiconductor wafer. Furthermore, assuming that warpage occurs on the wafer 10 during back-grinding, each semiconductor wafer 15 will also be improved in flatness by the thermosetting protective film forming film 22 that is thermally cured in the thermal curing step. Curvature decreases.

In addition, in this manufacturing method, the thermal curing step is performed in a state where a plurality of semiconductor wafers 15 are attached to the thin film 20 for forming a protective film with a support. Therefore, the support is deformed by heat, which may cause defects such as slack. The situation is likely to happen. Here, the base material constituting the support has better heat resistance. As a substrate having heat resistance, specifically, as will be described later, there is at least a polyester film or a polypropylene film.

Furthermore, in the present manufacturing method, by performing the protective film cutting step after the thermosetting step, the thin film 22 for forming a thermosetting protective film is not divided at the time of thermosetting. Therefore, in the thermal hardening step, each wafer 15 Since they are held together on the thin film 22 for forming a thermosetting protective film, each wafer can be prevented from being warped individually, and warpage can be effectively suppressed.

Moreover, in the present invention, if the support 21 is attached to the ring frame 25 during thermal curing, the semiconductor wafer 15 and the support 21 are integrally supported by the ring frame 25, so the above wafer can be prevented more effectively Warpage.

Moreover, if the organic film 13 is provided on the front surface of the semiconductor wafer 10, the semiconductor wafer 10 and the semiconductor wafer 15 may be easily warped due to the thermal contraction of the organic film 13, but by using the previous dicing method as described above, and The pick-up step is performed after the heat-hardening step, which can effectively prevent warpage caused by the organic film 13. Similarly, although the elongated semiconductor wafer 15 is also prone to warp, by using the previous dicing method and performing the pick-up step after the thermal hardening step, the warp can also be effectively prevented.

Furthermore, the thin film 22 for forming a thermosetting protective film is hardened to become the protective film 22A, so that the adhesion is lost. Therefore, by performing the protective film cutting step after the thermal hardening step, the debris generated by cutting the protective film 22A is more difficult to adhere to the wafer.

[Thin film for forming protective film with support]

Hereinafter, the configuration of each member of the thin film for forming a protective film with a support used in the manufacturing method of the semiconductor device and the manufacturing method thereof will be described.

<substrate>

The substrate 21A of the support 21 used in the film 20 for forming a protective film with a support is not limited as long as it is suitable for the processing of the semiconductor wafer 10, and is usually made of a resin film using a resin-based material as a main material Posed.

Specific examples of the resin film include polyethylene films such as low density polyethylene (LDPE) films, linear low density polyethylene (LLDPE) films, and high density polyethylene (HDPE) films, polypropylene films, and polybutylene. Polyolefin films such as vinylene films, polybutadiene films, polymethylpentene films, ethylene-norbornene copolymer films, norbornene resin films; ethylene-ethylene acetate copolymer films, ethylene -(Meth)acrylic copolymer film, ethylene-(meth)acrylate copolymer film and other vinyl-based copolymer films; polyvinyl chloride film, vinyl chloride copolymer film and other polyvinyl chloride-based films; Polyester films such as polyethylene terephthalate film, polybutylene terephthalate film, etc.; polyurethane film; polyimide film; polystyrene film; polycarbonate film; Fluorine resin film, etc. And modified films such as such crosslinked films and ionomer films can also be used. The base material may be a film made of one of these, or a laminated film in which two or more types of these are combined.

From the viewpoint of versatility, the viewpoint of high strength and easy prevention of warpage, or the viewpoint of preventing wafer movement in the above-mentioned attaching step, and the viewpoint of heat resistance, the resin film is made of polyethylene terephthalate Polyester films such as ester films, polybutylene terephthalate, and polypropylene films are preferred. In order to obtain such an effect, the base material only needs to have at least one layer selected from the group consisting of a polyester film and a polypropylene film, or a single-layer film or Laminated film. In order to enable easy expansion in the pickup step, and from the viewpoint of easy peeling of the protective film or the like from the support in the pickup itself, it is particularly preferable that the base material has a polypropylene film. As a laminated film combining a polypropylene film and other types of films, for example, the base material described in International Publication No. WO2013/172328 can also be used.

The thickness of the substrate 21 is not particularly limited, but it is preferably in the range of 20 to 450 μm, and more preferably in the range of 25 to 400 μm.

<adhesive layer>

The adhesive layer 21B of the support 21 used in the film 20 for forming a protective film with a support can use acrylic adhesives, rubber adhesives, silicone adhesives, urethane adhesives, poly Ester adhesives, polyvinyl ether adhesives, etc., but among these, acrylic adhesives are preferred.

The acrylic adhesive contains an acrylic copolymer (a1) as a main component (adhesive main agent), and the acrylic copolymer (a1) contains, for example, a structural unit derived from a monomer containing a functional group and a functional group. Constituent units derived from (meth)acrylate monomers or derivatives other than monomers.

The functional group-containing monomer as a constituent unit of the acrylic copolymer (a1) is a monomer having a polymerizable double bond in the molecule, and a functional group such as a hydroxyl group, an amine group, a substituted amine group, and an epoxy group. good.

Specific examples of the functional group-containing monomer include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 3-hydroxy Propyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate and the like can be used alone or in combination of two or more.

As the (meth)acrylate monomer constituting the acrylic copolymer (a1), an alkyl (meth)acrylate having 1 to 20 carbon atoms and a cycloalkyl (meth)acrylate can be used , Benzyl (meth) acrylate. Among these, particularly preferred are alkyl (meth)acrylates having 1 to 18 carbon atoms, such as methyl (meth)acrylate, ethyl (meth)acrylate, and propyl (meth) Group) acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, etc.

The acrylic copolymer (a1) usually contains 3 to 50% by mass, preferably 5 to 35% by mass, of structural units derived from the above functional group-containing monomer, and usually 40 to 97% by mass. It is preferable to contain constituent units derived from (meth)acrylate monomers or their derivatives at a ratio of 60 to 95% by mass.

In the acrylic copolymer (a1), in addition to the above-mentioned functional group-containing monomer and the structural unit derived from the (meth)acrylate monomer or its derivative, it may also have dimethylacrylamide, vinyl formate, Constituent units derived from other monomers such as ethylene acetate and styrene.

In addition, the adhesive layer may be a material that hardens energy ray hardening type adhesives such as ultraviolet curing type or electron beam curing type. As the energy ray hardening type adhesive, there is a so-called internal energy ray hardening type which uses an acrylic copolymer having a radical-reactive carbon-carbon double bond in the molecule as a main component (adhesive main agent). Adhesive. The main component of the internal energy ray hardening adhesive can be copolymerized by, for example, the above acrylic The compound (a1) is obtained by reacting with a compound containing an unsaturated group, the compound containing an unsaturated group has a substituent bonded to the functional group of the acrylic copolymer (a1), and a radical-reactive carbon-carbon double bond .

In addition, the energy ray-curable adhesive may be a polymer component that does not have the energy ray-curability of the acrylic copolymer (a1) or the like, and a multifunctional monomer and/or oligomer with energy ray-curability The mixture is the main component of the so-called additive energy ray hardening adhesive. As the energy ray-curable polyfunctional monomer and/or oligomer, for example, an ester of polyhydric alcohol and (meth)acrylic acid can be used.

In addition, the adhesive agent can be blended with a crosslinking agent, a photopolymerization initiator, etc. in addition to the adhesive main agent such as acrylic copolymer, etc., as necessary. As the crosslinking agent, a multifunctional compound having reactivity with a functional group contained in a polymer (adhesive main agent) such as an acrylic copolymer can be used. Examples of such polyfunctional compounds include isocyanate compounds, epoxy compounds, amine compounds, melamine compounds, aziridine compounds, hydrazine compounds, aldehyde compounds, oxazoline compounds, metal alkoxy compounds, and metal chelates. Compounds, metal salts, ammonium salts, reactive phenol resins, etc.

The thickness of the adhesive layer 21B is not particularly limited, but it is preferably about 1 to 50 μm, more preferably 2 to 30 μm.

However, the support 21 has a thin film 22 for forming a thermosetting protective film. As long as the thin film 22 can be supported, it is not limited to the above-mentioned configuration, and the adhesive layer may be omitted, for example. At this time, in order to adjust the peelability between the thin film 22 for forming a thermosetting protective film and the support 21, for example, support The body 21 may also have a layer formed by a silicone stripping agent or the like.

<Thin film for forming thermosetting protective film>

The thin film 22 for forming a thermosetting protective film is preferably made of an uncured thermosetting adhesive. The film 22 for forming a thermosetting protective film is attached to the semiconductor wafer 10 (semiconductor wafer 15) and then thermally cured, so that the protective film 22A can be strongly adhered to the semiconductor wafer 10 to form durability on the wafer 15 Excellent protective film 22A.

The thin film 22 for forming a thermosetting protective film has adhesiveness at normal temperature, or it is preferable to exert adhesiveness by heating. By this, it is easy to attach to the semiconductor wafer 10 (semiconductor wafer 15). The thermosetting adhesive preferably contains a thermosetting component and a binder polymer component.

Examples of the thermosetting component include epoxy resin, phenol resin, melamine resin, urea resin, polyester resin, urethane resin, acrylic resin, polyimide resin, benzoxazine resin, etc. Wait for the mixture. Among these, the use of epoxy resins, phenol resins, and mixtures of these are preferred.

After being heated, the epoxy resin undergoes three-dimensional meshing and has the property of forming a strong coating. As such an epoxy resin, various conventionally known epoxy resins are used, and those having a molecular weight of approximately 300 to 2000 are generally preferred, and those having a molecular weight of 300 to 500 are particularly preferred. Furthermore, it is preferably used in the form of mixing an epoxy resin that is liquid in the normal state with a molecular weight of 330 to 400 and an epoxy resin that is solid at a normal temperature with a molecular weight of 400 to 2500, especially 500 to 2000. Moreover, the epoxy equivalent of epoxy resin is 50~5000g/eq is better.

Specific examples of such epoxy resins include glycidyl ethers of phenols such as bisphenol A, bisphenol F, resorcinol, phenyl novolac, and cresol novolac; butanediol and polyethylene di Glycidyl ethers of alcohols such as alcohol and polypropylene glycol; glycidyl ethers of carboxylic acids such as phthalic acid, isophthalic acid, and tetrahydrophthalic acid; active hydrogen bonded to nitrogen atoms such as aniline isocyanic acid Epoxypropyl substituted glycidyl or alkyl glycidyl epoxy resin; such as vinylcyclohexane diepoxide, 3,4-epoxycyclohexylmethyl-3,4-dicyclohexyl Alkanecarboxylic acid, 2-(3,4-epoxy)cyclohexyl-5,5-helix (3,4-epoxy)cyclohexene-m-dioxane, etc. The carbon double bond is a so-called alicyclic epoxy compound in which an epoxy group is introduced by, for example, oxidation. In addition, an epoxy resin having a biphenyl skeleton, a dicyclohexadiene skeleton, a naphthalene skeleton, etc., a dicyclopentadiene type epoxy resin, etc. can be used.

Among these, bisphenol-based glycidyl epoxy resin, o-cresol novolac epoxy resin, and phenol novolac epoxy resin are preferably used.

These epoxy resins can be used alone or in combination of two or more.

When an epoxy resin is used as a thermosetting component, it is preferable to use a thermoactive latent epoxy resin hardener as an auxiliary agent. Thermally active latent epoxy resin hardener means a type of hardener that does not react with epoxy resin at room temperature, is activated by heating above a certain temperature, and reacts with epoxy resin. Among the activation methods of the heat-active latent epoxy resin hardener, there is a method of generating active species (anions, cations) by a chemical reaction of heating; it is stably dispersed in the epoxy resin at about room temperature and Compatible with epoxy resin at high temperature. The method of dissolving and starting the hardening reaction; the method of dissolving the hardener with molecular sieve seal at high temperature and starting the hardening reaction; the method of microcapsules, etc.

As specific examples of the heat-active latent epoxy resin hardener, various high-melting points such as various onium salts, dibasic acid dihydrazide compounds, dicyandiamide, amine adduct hardeners, imidazole compounds, etc. can be mentioned. Active hydrogen compounds, etc. These thermally active latent epoxy resin hardeners can be used alone or in combination of two or more. The heat-active latent epoxy resin hardener as described above is preferably 0.1 to 20 parts by weight, preferably 0.2 to 10 parts by weight, and more preferably 0.3 to 5 parts by weight relative to 100 parts by weight of the epoxy resin. To use.

As the phenol-based resin, there are used condensates of phenols and aldehydes such as alkylphenols, polyhydric phenols, naphthols, and the like, and is not particularly limited. Specifically, there are phenol novolak resin, o-cresol novolak resin, p-cresol novolak resin, t-butylphenol novolak resin, dicyclopentadiene cresol resin, poly-p-vinyl phenol resin, bisphenol Phenolic A type phenolic resin, or these modified products, etc.

The phenolic hydroxyl group contained in these phenol resins will easily undergo an addition reaction with the epoxy group of the epoxy resin by heating, and can form a hardened product with high impact resistance. Therefore, epoxy resin and phenol resin can also be used together.

The binder polymer component can impart moderate adhesion to the thermosetting protective film forming film 22 and improve the operability of the protective film forming film 20 with a support. Average weight of binder polymer The sub-weight is usually from 50,000 to 2 million, preferably from 100,000 to 1.5 million, and particularly preferably from 200,000 to 1 million. If the molecular weight is too low, the film formation of the thermosetting protective film forming film 22 becomes insufficient, and if it is too high, the compatibility with other components becomes poor, and as a result, uniform film formation is hindered. As such a binder polymer, for example, acrylic polymers, polyester resins, phenoxy resins, urethane resins, silicone resins, rubber polymers, etc. are used, and acrylic polymers are particularly preferably used.

Examples of the acrylic polymer include (meth)acrylate copolymers composed of structural units derived from (meth)acrylic acid derivatives. Here, as the (meth)acrylic acid derivative, in addition to (meth)acrylic acid itself, (meth)acrylic acid ester monomers are also mentioned. In addition, the (meth)acrylate copolymer contains structural units derived from (meth)acrylate monomers. As the (meth)acrylate monomer, it is preferable to use an alkyl (meth)acrylate having 1 to 18 carbon atoms, such as methyl (meth)acrylate, ethyl (meth)acrylate, ( Propyl meth)acrylate, butyl (meth)acrylate, etc. In addition, a (meth)acrylate monomer having an epoxy group or a hydroxyl group, such as glycidyl (meth)acrylate, hydroxyethyl (meth)acrylate, or the like can be given.

Among the above, if glycidyl methacrylic acid or the like is used as a structural unit, and the glycidyl group is introduced into the acrylic polymer, the compatibility with the epoxy resin as the thermosetting component is improved, and the thermosetting protective film The glass transition temperature (Tg) after hardening of the forming film 22 becomes higher, and the heat resistance is improved. Furthermore, among the above, if hydroxyethyl acrylate or the like is used as a structural unit and the hydroxyl group is introduced into the acrylic polymer, then Control the adhesion or physical properties of the semiconductor wafer.

When an acrylic polymer is used as the binder polymer, the weight average molecular weight of the polymer is preferably 100,000 or more, and particularly preferably 150,000 to 1 million. The glass transition temperature of the acrylic polymer is usually 30°C or lower, preferably about -70 to 10°C.

The blending ratio of the thermosetting component and the binder polymer component is relative to 100 parts by weight of the binder polymer component, and the blending is preferably 50 to 1500 parts by weight, more preferably 70 to 1000 parts by weight, and more preferably It is 80~800 parts by weight of thermosetting components. If the thermosetting component and the binder polymer component are blended in such a ratio, moderate adhesion will be shown before curing, the attachment work can be performed stably, and a protective film with excellent coating strength can be obtained after curing.

The thin film 22 for forming a thermosetting protective film may contain at least any one of a colorant and a filler. With this, the light transmittance of the protective film 22A is controlled within a desired range, and laser printing with excellent visibility can be obtained.

In addition, if the thin film 22 for forming a thermosetting protective film contains a filler, the hardness of the protective film 22A after curing can be maintained at a high level, and at the same time, the moisture resistance can be improved. Furthermore, the thermal expansion coefficient of the hardened protective film 22A can be made close to the thermal expansion coefficient of the semiconductor wafer 15, whereby the warpage of the semiconductor wafer 15 can be further reduced.

As the colorant, known ones such as inorganic pigments, organic pigments, and organic dyes can be used, and it is preferable to use organic pigments or organic dyes.

Examples of inorganic pigments include carbon black, cobalt pigments, iron pigments, chromium pigments, titanium pigments, vanadium pigments, zirconium pigments, molybdenum pigments, ruthenium pigments, platinum pigments, and ITO (oxidized Indium tin pigments, ATO (antimony tin oxide) pigments, etc.

Examples of the organic pigments and organic dyes include amine onium pigments, cyanine pigments, merocyanine pigments, crotonic acid pigments, squarylium pigments, chamomile pigments, and polymethine pigments. , Naphthoquinone-based pigments, pyran-based pigments, phthalocyanine-based pigments, naphthalocyanine-based pigments, naphthalene imide-based pigments, azo-based pigments, condensed azo-based pigments, indigo-based pigments, indigo-based pigments , Perylene pigment, bisoxazine pigment, quinacridone pigment, isoindolinone pigment, quinoline yellow pigment, pyrrole pigment, thioindigo pigment, metal complex pigment (metal complex salt) Dyes), dithiol metal complex pigments, indolephenol pigments, triene methane pigments, scallion pigments, dioxazine pigments, naphthol pigments, azomethine pigments, benzo Imidazolone-based pigments, picanthrone-based pigments, and reduced-based colors. These pigments or dyes can be appropriately mixed and used in order to adjust the light transmittance to the purpose.

Among these, pigments and inorganic pigments are particularly preferred, and among inorganic pigments, carbon black is particularly preferred. Carbon black is usually black. By laser light irradiation, the contrast difference between the portion where the concave portion is formed and the unirradiated portion becomes larger. Therefore, the visibility of the portion after laser printing is excellent.

Examples of the filler include silica, crystalline silica, fused silica, synthetic silica, and other inorganic fillers such as alumina and glass balloons. Among them, it is better to use synthetic silica, especially because it will become a mistake for semiconductor devices. Synthetic silica of the type that the source of the movement of the alpha line is most strongly removed is most suitable. The shape of the filler may be any of spherical, needle-shaped, and indefinite.

In addition, as the filler added to the thin film 22 for forming a thermosetting protective film, in addition to the above-mentioned inorganic filler, a functional filler may be blended. Examples of the functional fillers include gold, silver, copper, nickel, aluminum, stainless steel, carbon, ceramics, or silver-coated conductive fillers for the purpose of imparting conductivity after the wafer is bonded. , Or metal materials such as gold, silver, copper, nickel, aluminum, stainless steel, etc. or these alloys, oxides or nitrides of these metal materials, non-metals such as silicon, germanium, etc. for the purpose of giving thermal conductivity And thermally conductive fillers such as boron and other non-metal nitrides.

The blending amount of the coloring agent is usually 0.001 to 5% by mass, preferably 0.01 to 3% by mass, particularly preferably 0.1 to 2.5% by mass. Moreover, the blending amount of the filler is usually 40 to 80% by mass, preferably 50 to 70% by mass.

The thin film 22 for forming a thermosetting protective film may contain a coupling agent. By containing the coupling agent, after the thermosetting protective film forming film 22 is cured, the heat resistance of the protective film 22A is not impaired, the adhesion and adhesion of the protective film 22A and the wafer 15 can be improved, and at the same time Improve water resistance (moisture and heat resistance). As the coupling agent, silane coupling agent is preferred in view of its wide use and cost-effectiveness.

Examples of the silane coupling agent include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β- (3,4-Epoxycyclohexyl)ethyltrimethoxysilane, γ-(methacryloxypropyl)trimethoxysilane, γ-aminopropyltrimethoxysilane, N-6-(aminoethyl Group)-γ-aminopropyltrimethoxysilane, N-6-(aminoethyl)-γ-aminopropylmethyl diethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane Silane, γ-ureidopropyltriethoxysilane, γ-hydrothiopropyltrimethoxysilane, γ-hydrothiopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl ) Tetrasulfane, methyltrimethoxysilane, methyltriethoxysilane, ethylenetrimethoxysilane, ethylenetrimethoxysilane, imidazolesilane, etc. These can be used alone or in combination of two or more.

The film 22 for thermosetting protective film formation may contain a crosslinking agent such as an organic polyisocyanate compound, an organic polyamine compound, an organometallic chelate compound, etc. in order to adjust the cohesive force before curing. In addition, the thin film 22 for forming a thermosetting protective film may contain an antistatic agent in order to suppress static electricity and improve the reliability of the wafer. Furthermore, the thin film 22 for forming a thermosetting protective film may contain a flame retardant such as a phosphoric acid compound, a bromine compound, a phosphorous compound, etc. in order to improve the flame retardant performance of the protective film and improve the reliability as a casing.

The thickness of the thin film 22 for forming a thermosetting protective film is preferably 3 to 300 μm in order to effectively function as a protective film, particularly preferably 5 to 250 μm, and even more preferably 7 to 200 μm.

Before use, the thin film 20 for forming a protective film with a support may be protected by a peeling sheet. The peeling sheet is laminated on the surface opposite to the surface of the support 21 side of the thermosetting protective film forming film 22, and protects the thermosetting protective film forming film 22 exposed to the outside, to And the adhesive layer 21B and so on. An example of a peeling sheet is a person who peels a plastic film with a peeling agent or the like. The peeling sheet is a peeled sheet before the thin film 20 for forming a protective film with a support is attached to the semiconductor wafer 15 (semiconductor wafer 10).

[Production of thin film for forming protective film with support]

The thin film 20 for forming a protective film with a support can be produced by forming a thin film laminate for forming a protective film and a support and then bonding these together.

<Preparation of thin film laminate for forming protective film>

The thin-film laminate for forming a protective film is produced, for example, in the following manner.

The components constituting the film for forming a thermosetting protective film are mixed in a suitable solvent or in a solvent-free manner at an appropriate ratio to form a coating solution for a film for forming a protective film, and the coating solution is applied to the first release sheet The upper coating is dried, and a thin film for forming a thermosetting protective film is formed on the first release sheet. Next, a second release sheet was further attached to the thermosetting protective film forming film to obtain a protective film formed by a three-layer structure of a first release sheet/thermosetting protective film forming film/second release sheet. Use a film laminate. The thin film layered body for forming a protective film may be appropriately stored, transported, etc. as a rolled up body. In addition, in the above steps, the step of attaching the second release sheet may be omitted, and the film for forming a protective film may be directly exposed.

<Production of Support>

The following describes a method of manufacturing the support when the support includes a base material and an adhesive layer provided on one side of the base material.

The components of the adhesive layer are mixed in a suitable solvent in an appropriate ratio or in a solvent-free layer, and the coating solution for the adhesive layer is applied to the release sheet and dried to form an adhesive layer on the release sheet. , Laminating the substrate on the adhesive layer to obtain a support with a peeling sheet. The support with the peeling sheet can also be appropriately stored and transported as a rolled up body.

In addition, the coating liquid for the adhesive layer is directly applied to the substrate to form an adhesive layer, instead of being coated on the release sheet, and then, the release sheet can be further laminated on the adhesive layer as a support with a release sheet . However, the step of attaching and peeling the sheet can also be omitted, and the adhesive layer is directly exposed.

Here, when the adhesive layer provided on the base material is formed of an energy ray hardening type adhesive, the adhesive can also be irradiated with energy rays before being attached to the thermosetting protective film forming film After hardening, it can be irradiated with energy rays and hardened after being attached to the thin film for forming a thermosetting protective film. After bonding to the thin film for forming a thermosetting protective film, when irradiating the adhesive with an energy ray, the energy ray may be irradiated from any step in the picking step in the above-mentioned attaching step. When the adhesive irradiated with energy rays is hardened, at least the portion in contact with the film for forming the thermosetting protective film may be hardened.

<fit>

After that, if necessary, the peeling sheet (for example, the second peeling sheet) on one side of the thin film laminate for forming a protective film is peeled off. Support of release sheet The release sheet is peeled, and a film for forming a thermosetting protective film is laminated on the adhesive layer of the support to produce a film for forming a protective film with a support.

<Release processing>

Furthermore, the thin film laminate for forming a protective film may be applied to a support after being subjected to release processing as necessary.

The release process is performed by cutting the above-mentioned thin film laminate for protective film formation in half in such a manner as to cut off one side of the release sheet (for example, the second release sheet) and the thermosetting protective film forming film. For example, a circle with the same size or a large circle, and then, the peeling sheet on one side and the film for forming a thermosetting protective film are removed from the circle that is half-cut. Similarly, it is also possible to form an appropriate cut in the support and then adjust its shape appropriately.

Furthermore, as shown in FIG. 8, when the adhesive layer for the ring-shaped frame is provided, the film for forming a protective film with a support can also be produced in the same manner, but as long as the film for forming a thermosetting protective film is bonded to the film It is sufficient to form an adhesive layer suitable for the ring-shaped frame on the surface opposite to the surface of the support.

[Example]

Hereinafter, the present invention will be further specifically described with examples, but the scope of the present invention is not limited to these examples.

In the examples and comparative examples, the wafer with a protective film after being picked up was evaluated by the following method.

<wafer warpage>

As shown in FIG. 10, the wafer 24 with a protective film picked up is placed on the glass plate 40 with the front surface of the wafer on the upper side, and the difference between the lowest position S and the highest position H of the wafer 24 is measured as the warpage in this state. Curvature. A wafer warpage amount of 300 μm or less is evaluated as “A”, when it exceeds 300 μm and 600 μm or less, it is evaluated as “B”, when it exceeds 600 μm and 1 mm or less, it is evaluated as “C”, and when it is larger than 1 mm, it is evaluated as “D”.

[Example 1] (1) Fabrication of a thin film laminate for forming a protective film

First, the following components (a) to (f) were mixed and diluted with methyl ethyl ketone to make the solid content concentration 61% by mass to obtain a coating liquid for a thin film for forming a protective film.

(a) Binder polymer: copolymerize 10 parts by mass of n-butyl acrylate, 70 parts by mass of methacrylate, 5 parts by mass of glycidyl methacrylate, and 15 parts by mass of 2-hydroxyethyl acrylate ( 100 parts by mass of meth)acrylate copolymer (solid content conversion is the same below); weight average molecular weight: 800,000, glass transition temperature: -1℃

(b) Thermosetting components: bisphenol A epoxy resin (manufactured by Mitsubishi Chemical Corporation, jER828, epoxy equivalent 184~194g/eq) 60 parts by mass, bisphenol A epoxy resin (manufactured by Mitsubishi Chemical Corporation) , JER1055, epoxy equivalent of 800~900g/eq) 10 parts by mass, and dicyclopentadiene type epoxy resin (made by Great Japan Ink Chemical Industry Co., Ltd., EPICLON HP-7200HH, epoxy equivalent 255~260g/eq) 30 parts by mass

(c) Thermally active latent epoxy resin hardener: dicyandiamide (made by ADEKA Corporation, ADEKA HARDENER EH-3636AS, active hydrogen content 21g/eq) 2 parts by mass, and 2-phenyl-4,5- Dihydroxymethylimidazole (made by Shikoku Chemical Industry Co., Ltd., Curezol 2PHZ) 2 parts by mass

(d) Colorant: carbon black (Made by Mitsubishi Chemical Corporation, #MA650, average particle diameter 28 nm) 0.6 parts by mass

(e) Filler: silica filler (manufactured by Admatechs, SC2050MA, average particle size 0.5 μm) 320 parts by mass

(f) Silane coupling agent: γ-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.: KBM-403, methoxy equivalent: 12.7 mmol/g, molecular weight: 236.3) 0.4 parts by mass

The above-mentioned coating liquid for forming a protective film was applied to the peeling surface of the first release sheet (produced by Lintec Corporation, SP-PET3811, thickness 38 μm), dried in an oven at 120° C. for 2 minutes, and applied to the first release sheet A thin film for forming a thermosetting protective film is formed thereon. The thickness of the thin film for forming a thermosetting protective film after formation was 25 μm. A peeling surface of a second release sheet (produced by Lintec Corporation, SP-PET381031, thickness 38 μm) was bonded to the film for forming a thermosetting protective film to obtain the first release sheet/film for forming a thermosetting protective film/ A thin film laminate for forming a protective film formed by a three-layer structure of a second release sheet. This layered body is longer, and the take-up is taken as the take-up body.

Laminating the long thin film for protective film formation obtained above The retracted body is cut 300mm in the width direction. Next, a diameter is applied continuously to the central portion in the width direction of the layered body of the thin film laminate for forming a protective film from the second release sheet side so as to cut the second release sheet and the thermosetting protective film forming film 220mm round half cut. After that, the second peeling sheet and the thermosetting protective film forming film existing outside the circle formed by half-cutting are removed. In this way, the thin film layering system for forming a protective film is formed by stacking a circular thermosetting protective film forming film and a circular second release sheet on the peeling surface of the first release sheet.

(2) Production of support

First, the components (g) and (h) were mixed so that the solid content concentration became 30% by mass, and diluted with methyl ethyl ketone to prepare a coating agent for an adhesive layer.

(g) Adhesive main agent: (meth)acrylate copolymer (copolymerized with 40 parts by mass of butyl acrylate, 55 parts by mass of 2-ethylhexyl acrylate, and 5 parts by mass of 2-hydroxyethyl acrylate) Copolymer, weight average molecular weight: 600,000) 100 parts by mass

(h) Crosslinking agent: aromatic polyisocyanate compound (Makei Chemical Co., Ltd., Takenate D110N) 10 parts by mass

The above-mentioned adhesive layer coating agent was applied to the peeling surface of a release sheet (manufactured by Lintec Co., Ltd.: SP-PET381031) with a blade coating film, and dried to form an adhesive layer. The thickness of the adhesive layer after formation was 10 μm. After that, apply a polymer with a thickness of 100 μm to the adhesive layer A substrate made of acrylic film (manufactured by Mitsubishi Resin Co., Ltd., trade name "CT265") was obtained with a support having a peeling sheet. The support body with the peeling sheet is longer, and it is taken up as a winding body, and then cut 300mm in the width direction.

(3) Production of a thin film for forming a protective film with a support

The circular second peeling sheet was peeled from the thin film laminate for forming a protective film obtained in the above (1) to expose the circular thin film for forming a thermosetting protective film. On the other hand, the release sheet-attached support obtained from (2) above peels the release sheet to expose the adhesive layer. A support is attached to the film laminate for forming a protective film so that its adhesive layer is in contact with the film for forming a thermosetting protective film, and a film protected by a release sheet is provided on the film side for forming a thermosetting protective film. A thin film for forming a protective film of a support.

The resulting film for forming a protective film with a support was cut from the substrate side to the substrate and the adhesive layer to obtain a film having a thermosetting protective film having a diameter of 220 mm laminated on a support having a diameter of 270 mm. A thin film for forming a protective film with a support. However, the film for forming a protective film with a support is protected by the first release sheet on the side of the film for forming a thermosetting protective film.

(4) Fabrication of wafers with protective film

Next, using the above-mentioned thin film for forming a protective film with a support, the following steps were performed to produce a wafer with a protective film.

Pre-processing steps: Using Dicer DFD6361 made by DISCO, a stock company, half-cut the 600 μm thick wafer 10 with a 10 μm thick polyimide film (organic film 13) on the front surface of the wafer to form a groove 11 with a depth of 180 μm (refer to FIG. 1 ).

Wafer singulation step: Next, using the Laminator RAD-3510F/12 manufactured by Lintec Corporation, the back surface abrasive tape 16 (Adwill E-3125 manufactured by Lintec Corporation) is attached to the front surface of the wafer 10, and then used by the company DISCO Grinder DFG8760 was manufactured, the wafer 10 was polished from the back side to a thickness of 150 μm, and the wafer 10 was singulated into a plurality of wafers 15 (see FIGS. 2 and 3 ).

Attaching procedure: Using Mounter RAD-2700F/12 made by Lintec Co., Ltd., the thin film 20 for forming a protective film with a support peeled off the first release sheet is attached to the wafer 10 of the single wafer 15 at a temperature of 70°C back. At this time, an annular frame 25 (see FIG. 4) is attached to the outer peripheral area of the thin film 20 for forming a protective film with a support. After that, the back polishing tape 16 was irradiated with UV under the condition of 500 mJ/cm ² , and the back polishing tape 16 was cured after the adhesive layer for the back polishing tape was cured.

Thermal hardening step: Next, the film 20 for forming a protective film with a support attached to the plurality of wafers 15 and the ring frame 25 is placed in an oven 30 at 130°C for 2 hours, and the film for forming a thermosetting protective film is placed 22 is hardened to obtain a protective film 22A (see FIG. 5).

Protective film division step: After that, the Dicer DFL7160 made by DISCO Co., Ltd. was used to cut the protective film 22A exposed between the wafers 15 with a laser, the protective film 22A was divided, and then washed with a spinner (See Figure 6).

Picking up step: Next, the die-attached wafers 24 with the protective film 22A on the back area layer after being divided are picked up using Die Bonder BESTEM D02 manufactured by Canon-machinery Co., Ltd., and peeled off from the support 21 (see FIG. 7 ). The obtained wafer 24 with a protective film has a wafer size of 1 mm in width and 20 mm in length.

[Example 2]

A wafer with a protective film was produced in the same manner as in Example 1 except that the thermal curing step and the protective film dividing step were replaced, and the thermosetting protective film forming film was divided and then thermally cured.

[Comparative Example 1]

The thermosetting step is not performed between the attaching step and the protective film dividing step. The singulated wafer after the picking step is placed in an oven at 130° C. for 2 hours, except that the thermosetting protective film forming film is cured. As in Example 1, a wafer with a protective film was produced.

[Comparative Example 2]

The groove forming step is not performed, and the wafer is not singulated by back grinding in the wafer singulation step. Furthermore, instead of performing the above protective film dividing step, the wafer and the protective film are simultaneously cut by cutting the blade from the front side of the wafer by cutting the support 10 μm to obtain a wafer with a protective film singulated. Comparative Example 2 is the same as Example 1 except for the above points To produce wafers with protective films.

For each of the above-mentioned embodiments and comparative examples, evaluation was performed based on the above-mentioned evaluation method. Table 1 shows the results.

From the results of Examples 1 and 2 above, it is clear that while the semiconductor wafer is singulated by the previous dicing method, by thermally curing the thin film for forming a thermosetting protective film before picking up, the warpage of the wafer can be suppressed song. Furthermore, by thermally curing the protective film before it is divided, the warpage of the wafer can be more effectively suppressed.

On the other hand, in Comparative Example 1, since the thin film for forming a thermosetting protective film is thermoset after picking up, the warpage of the wafer cannot be sufficiently suppressed. Furthermore, in Comparative Example 2, since the wafer is singulated after dicing without using the previous dicing method, the warpage of the wafer cannot be sufficiently suppressed.

Claims (9)

A manufacturing method of a semiconductor device, which includes a process step of forming a groove from the front side of a semiconductor wafer, or forming a modified region on the semiconductor wafer, and attaching the semiconductor wafer to the front surface of the wafer with a back grinding tape A wafer singulation step where the semiconductor wafer is singulated into a plurality of wafers along the aforementioned grooves or modified regions is polished from the back side, and a thin film for forming a thermosetting protective film on the support is attached The step of attaching the thermosetting film-forming film side of the film for forming a protective film of the support to the back surface of the singulated semiconductor wafer and the heat applied to the semiconductor wafer The thermosetting film for forming a curable protective film is thermally cured, and after the thermal curing step of forming a protective film and the thermal curing step, a pickup step of picking up a wafer with a protective film on which the protective film is deposited on the wafer and Peel the back grinding tape in the aforementioned attaching step. The method for manufacturing a semiconductor device according to claim 1, wherein the support has a substrate, and the substrate has at least one layer of a film composed of one selected from the group consisting of polyester films and polypropylene films . The method for manufacturing a semiconductor device according to claim 1 or 2, further comprising a film or a protective film for forming a thermosetting protective film attached to the back surface of the semiconductor wafer, cut along the wafer interval, and divided into corresponding parts Protective film division step for various wafer shapes. The method of manufacturing a semiconductor device according to claim 3, wherein The aforementioned protective film division step is performed between the thermal hardening step and the aforementioned pickup step. The method for manufacturing a semiconductor device according to claim 1 or 2, wherein the thin film for forming a protective film with a support is held in a ring frame, and in this state, the thin film for forming a thermosetting protective film is heated Harden and make a protective film. The method for manufacturing a semiconductor device according to claim 1 or 2, wherein the semiconductor wafer is covered with an organic film on its front surface. The method for manufacturing a semiconductor device according to claim 1 or 2, wherein the aforementioned wafer has an elongated shape. The method for manufacturing a semiconductor device according to claim 1 or 2, wherein the back polishing tape includes a base material for back polishing tape, and an adhesive layer for back surface polishing tape provided on the base material. The method for manufacturing a semiconductor device according to claim 8, wherein the adhesive in the adhesive layer for the back-grinding tape is an energy ray hardening adhesive.

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