Temporary protective film for manufacturing semiconductor device and method for manufacturing semiconductor device

Abstract

A temporary protective film for manufacturing a semiconductor device is provided with: a support film; and an adhesive layer provided on the support film, the adhesive layer containing: a polymer containing an alkyl (meth) acrylate, a (meth) acryloylmorpholine, and a monomer having a crosslinkable group as monomer units; and a crosslinking agent crosslinkable with the crosslinkable group, the content of (meth) acryloylmorpholine being 7 mass% or more based on the total amount of monomer units in the polymer.

Description

Technical Field

[0001] The present invention relates to a temporary protective film for manufacturing a semiconductor device and a method for manufacturing a semiconductor device. Background Art

[0002] In a semiconductor package, a structure is sometimes adopted in which a sealing layer is formed only on the semiconductor element side of a lead frame, and the back side of the lead frame is exposed. In the manufacture of a semiconductor package having such a structure, it is possible that the sealing material is wound around the back side of the lead frame when the sealing layer is formed. In order to prevent this, a method of attaching a temporary protective film to the back side of the lead frame is known (Patent Document 1). After the sealing layer is formed, the temporary protective film is peeled off from the lead frame.

[0003] Previous technical literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2001 / 035460 Summary of the invention

[0006] Technical issues to be solved by the invention

[0007] The temporary protective film preferably has excellent adhesion to an adherend such as a lead frame at room temperature (eg, 25° C.), and the adhesive component of the temporary protective film does not remain on the adherend when the temporary protective film is peeled off from the adherend. However, it is not always easy to achieve both.

[0008] Therefore, an object of one aspect of the present invention is to provide a temporary protective film which has excellent adhesive strength at room temperature and can suppress the residual on the adherend when peeling.

[0009] Means for solving technical problems

[0010] The present inventors have studied the use of a polymer containing, as monomer units, an alkyl (meth)acrylate, (meth)acryloylmorpholine, and a monomer having a crosslinking group in the adhesive layer of a temporary protective film. The results show that when the content of (meth)acryloylmorpholine is above a specific amount, both excellent adhesion at room temperature and suppression of residue on an adherend can be achieved.

[0011] The present invention includes the following aspects.

[0012] [1] A temporary protective film for semiconductor device manufacturing, comprising: a support film; and an adhesive layer disposed on the support film, the adhesive layer comprising: a polymer, comprising as monomer units an alkyl (meth)acrylate, (meth)acryloylmorpholine, and a monomer having a crosslinking group; and a crosslinking agent capable of crosslinking with the crosslinking group, wherein the content of (meth)acryloylmorpholine is 7% by mass or more, based on the total amount of monomer units in the polymer.

[0013] [2] The temporary protective film according to [1], wherein the crosslinkable group is an acidic group and the crosslinking agent has an epoxy group.

[0014] [3] The temporary protective film according to [2], wherein the cross-linking agent further has an amino group.

[0015] [4] The temporary protective film according to any one of [1] to [3], wherein the crosslinking agent has a group represented by the following formula (1).

[0016]

[0017] [5] A method for manufacturing a semiconductor device, which comprises, in sequence: a step of attaching a temporary protective film to one side of a substrate; a step of mounting a semiconductor element on the surface of the substrate opposite to the temporary protective film; a step of sealing the semiconductor element; and a step of peeling the temporary protective film from the substrate, wherein the temporary protective film comprises: a support film; and an adhesive layer provided on the support film, the adhesive layer containing: a polymer, comprising, as monomer units, an alkyl (meth)acrylate, (meth)acryloylmorpholine, and a monomer having a crosslinking group; and a crosslinking agent capable of crosslinking with the crosslinking group, wherein the content of (meth)acryloylmorpholine is 7% by mass or more based on the total amount of monomer units in the polymer.

[0018] [6] The production method according to [5], wherein the crosslinkable group is an acidic group and the crosslinking agent has an epoxy group.

[0019] [7] The production method according to [6], wherein the cross-linking agent further has an amino group.

[0020] [8] The production method according to any one of [5] to [7], wherein the crosslinking agent has a group represented by the following formula (1).

[0021]

[0022] Effects of the Invention

[0023] According to one aspect of the present invention, it is possible to provide a temporary protective film which has excellent adhesive strength at room temperature and can suppress residue on an adherend when peeled off. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a cross-sectional view showing one embodiment of the temporary protective film.

[0025] Figure 2 This is a cross-sectional view for explaining one embodiment of a method for manufacturing a semiconductor device.

[0026] Figure 3 This is a cross-sectional view for explaining one embodiment of a method for manufacturing a semiconductor device.

[0027] Figure 4 It is a cross-sectional view showing one embodiment of a semiconductor device.

[0028] Figure 5 It is a perspective view showing one embodiment of the reel body. DETAILED DESCRIPTION

[0029] Hereinafter, embodiments of the present invention will be described. Figure 1 1 is a cross-sectional view showing a temporary protective film according to one embodiment. Figure 1 As shown, a temporary protective film 10 according to one embodiment includes a support film 1 and an adhesive layer 2 provided on the support film 1. The temporary protective film 10 can be used as a temporary protective film for semiconductor device manufacturing. More specifically, the temporary protective film 10 is attached to the back side of the lead frame (the side opposite to the side on which the semiconductor element is mounted) in a sealing molding process for forming a sealing layer for sealing a semiconductor element mounted on a die pad of a lead frame, and can be used as a temporary protective film for semiconductor sealing molding for temporarily protecting the lead frame during the sealing molding.

[0030] The support film 1 can be, for example, at least one polymer film selected from the group consisting of polyimide, polyamide, polyamideimide, polysulfone, polyethersulfone, polyphenylene sulfide, polyetherketone, polyarylate, polyetheretherketone and polyethylene naphthalate, and can preferably be a polyimide film. The polyimide can be an aromatic polyimide. The support film 1 can be a copper, aluminum, stainless steel or nickel film. When the support film 1 is a polymer film, its surface can be treated by chemical treatment such as alkali treatment, silane coupling treatment, physical treatment such as sand pad treatment, plasma treatment and corona treatment.

[0031] The thickness of the support film 1 may be, for example, 5 μm or more, 100 μm or less, or 50 μm or less. The ratio T2 / T1 of the thickness T2 of the adhesive layer 2 to the thickness T1 of the support film 1 may be 0.1 or more, and 0.5 or less, 0.3 or less, or 0.2 or less.

[0032] The adhesive layer 2 contains a polymer (hereinafter also referred to as “acrylic polymer”) containing, as monomer units, alkyl (meth)acrylate, (meth)acryloylmorpholine, and a monomer having a crosslinking group (hereinafter also referred to as “crosslinking monomer”).

[0033] The alkyl group (alkyl part other than the (meth)acryloyl group) in the alkyl (meth)acrylate may be linear or branched. The number of carbon atoms in the alkyl group may be 2 or more, or 3 or more, and may be 30 or less, 20 or less, 10 or less, 7 or less, 5 or less, or 4 or less, and may be 2 or 4.

[0034] Examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, n-hexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, and decyl (meth)acrylate.

[0035] The crosslinkable monomer has, in addition to the crosslinkable group, a polymerizable group that can copolymerize with the (meth) alkyl acrylate and the (meth) acryloyl morpholine. The polymerizable group may be, for example, an ethylenically unsaturated group. The crosslinkable group may be, for example, an acidic group. The acidic group may be, for example, a carboxyl group or a sulfonic group, preferably a carboxyl group.

[0036] Examples of the crosslinkable monomer having a carboxyl group include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, monohydroxyethyl phthalate acrylate, and 2-acryloyloxyethyl succinate.

[0037] In the acrylic polymer, as a monomer unit, other monomers other than (meth) alkyl acrylate, (meth) acryloyl morpholine and cross-linking monomers may be further included. As other monomers, for example, a polymerizable group (such as an ethylenically unsaturated group) and a monomer having a hydroxyl group may be used. As examples of the monomer, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate and other (meth) acrylate hydroxyalkyl esters; (4-hydroxymethylcyclohexyl) (meth) acrylate methyl hydroxyalkyl cycloalkanes and the like may be cited.

[0038] In the acrylic polymer, the content of (meth) acryloyl morpholine is 7% by mass or more based on the total amount of monomer units in the acrylic polymer. Thus, it is possible to obtain a temporary protective film having excellent adhesion at room temperature and remaining on the adherend during peeling. Based on the total amount of monomer units in the acrylic polymer, the content of (meth) acryloyl morpholine is preferably 7.5% by mass or more, 8% by mass or more, 8.5% by mass or more, or 9.0% by mass or more, and can be 20% by mass or less, 18% by mass or less, 17% by mass or less, 16.5% by mass or less, or 16% by mass or less.

[0039] The content of the alkyl (meth)acrylate may be 70 mass % or more, 75 mass % or more, or 80 mass % or more, and 92 mass % or less, 90 mass % or less, or 88 mass % or less, based on the total amount of monomer units in the acrylic polymer.

[0040] The content of the crosslinking monomer may be 1 mass % or more, 2 mass % or more, or 3 mass % or more, and may be 10 mass % or less, 6 mass % or less, or 4 mass % or less, based on the total amount of monomer units in the acrylic polymer.

[0041] The content of other monomers may be 0.1 mass % or more, 0.5 mass % or more, or 1 mass % or more, and 5 mass % or less, 4 mass % or less, or 3 mass % or less, based on the total amount of monomer units in the acrylic polymer.

[0042] The mass ratio of the content of (meth)acryloylmorpholine to the content of the alkyl (meth)acrylate ((meth)acryloylmorpholine / alkyl (meth)acrylate) may be 0.08 / 1 or more, 0.09 / 1 or more, or 0.1 / 1 or more, and may be 0.3 / 1 or less, 0.25 / 1 or less, 0.23 / 1 or less, 0.21 / 1 or less, or 0.2 / 1 or less.

[0043] The acid value of the acrylic polymer may be 10 mgKOH / g or more or 20 mgKOH / g or more, and may be 40 mgKOH / g or less or 30 mgKOH / g or less. The hydroxyl value of the acrylic polymer may be 1 mgKOH / g or more or 2 mgKOH / g or more, and may be 10 mgKOH / g or less or 5 mgKOH / g or less. The acid value and hydroxyl value of the acrylic polymer are measured according to the method described in JIS K0070.

[0044] The content of the acrylic polymer may be 80% by mass or more, 85% by mass or more, or 90% by mass or more, and may be 99.5% by mass or less, or 99% by mass or less, based on the total amount of the adhesive layer 2 .

[0045] The adhesive layer 2 further contains a crosslinking agent. The crosslinking agent is a crosslinking agent that can crosslink with the crosslinking group in the acrylic polymer. As such a crosslinking agent, a known crosslinking agent can be used. When the crosslinking group in the acrylic polymer is an acidic group, the crosslinking agent preferably has an epoxy group. The number of epoxy groups in the crosslinking agent can be 2 or more or 3 or more, and can be 4 or less, and can also be 4.

[0046] In one embodiment, the crosslinking agent may be a crosslinking agent having an amino group in addition to an epoxy group. The amino group may be an amino group in which a hydrogen atom in a -NH2 group is substituted (substituted amino group), or a tertiary amino group.

[0047] Such a cross-linking agent may have a group represented by the following formula (1).

[0048]

[0049] The number of the groups represented by the above formula (1) in the crosslinking agent may be one or two.

[0050] The cross-linking agent may be a cross-linking agent represented by the following formula (2).

[0051]

[0052] In the formula, X represents a divalent hydrocarbon group.

[0053] The divalent hydrocarbon group represented by X may be a divalent hydrocarbon group having a ring. The ring may be an aliphatic ring or an aromatic ring. The number of carbon atoms constituting the ring may be 5 or more, 8 or less, or 6. The number of rings in the divalent hydrocarbon group may be 1 or more, 3 or less, or 1 or 2. When the divalent hydrocarbon group contains a plurality of rings, the plurality of rings may be directly bonded to each other or bonded via an alkylene group having 1 to 3 carbon atoms.

[0054] The divalent hydrocarbon group represented by X preferably has a cycloalkylene group. The number of carbon atoms of the cycloalkylene group may be 5 or more and 8 or less. The cycloalkylene group is preferably a cyclohexylene group.

[0055] In one embodiment, the crosslinking agent may be a crosslinking agent having an ether group (without an amino group) in addition to an epoxy group. Such a crosslinking agent may have a group represented by the following formula (3).

[0056]

[0057] The number of the groups represented by the above formula (3) in the crosslinking agent may be 2 or more, or 3 or more, and may be 4 or less, or may be 2 or 4.

[0058] The cross-linking agent may be a cross-linking agent represented by the following formula (4).

[0059]

[0060] In the formula, m represents an integer of 2 or greater, n represents an integer of 0 or greater, and A represents a residue obtained by removing a hydroxyl group from a (m+n)-valent polyol.

[0061] m may be an integer greater than or equal to 3, or an integer less than or equal to 4, or 2 or 4. n may be an integer greater than or equal to 1, or an integer less than or equal to 2, or 0 or 2. m+n may be an integer greater than or equal to 2, or an integer less than or equal to 6.

[0062] The polyol in A may be an aliphatic polyol or a polyol having an ether group. The aliphatic polyol may have 2 or more, 3 or more, or 4 or more carbon atoms, and may have 10 or less, 9 or less, or 8 or less carbon atoms. The polyol having an ether group may be a polyalkylene glycol such as polyethylene glycol.

[0063] The crosslinking agent is preferably a crosslinking agent having the above-mentioned epoxy group and amino group. In this case, it is possible to suppress the deterioration of the appearance of the adherend after the temporary protective film is peeled off from the adherend (for example, the generation of an unnecessary pattern on the adherend).

[0064] Based on the total amount of the adhesive layer 2, the content of the crosslinking agent can be greater than 0.5 mass %, and can be less than 15 mass % or less than 10 mass %. From the viewpoint of suppressing the deterioration of the appearance of the adherend after the temporary protective film is peeled off from the adherend, it is preferably greater than 1 mass %, greater than 2 mass % or greater than 2.5 mass %.

[0065] The content of the crosslinking agent may be 0.5 parts by mass or more, and may be 15 parts by mass or less, or 10 parts by mass or less, relative to 100 parts by mass of the acrylic polymer. From the viewpoint of suppressing the deterioration of the appearance of the adherend after the temporary protective film is peeled off from the adherend, it is preferably 1 part by mass or more, 2 parts by mass or more, or 3 parts by mass or more.

[0066] The adhesive layer 2 may further contain other components in addition to the acrylic polymer and the crosslinking agent. Examples of other components include polymers other than the acrylic polymer and coupling agents.

[0067] The thickness of the adhesive layer 2 may be 1 μm or more, 2 μm or more, 3 μm or more, 4 μm or more, or 5 μm or more, and may be 20 μm or less, 18 μm or less, 16 μm or less, 14 μm or less, 12 μm or less, or 10 μm or less.

[0068] In another embodiment, the temporary protective film may further include a covering film disposed on the surface of the adhesive layer opposite to the support film. That is, the temporary protective film may include a support film, an adhesive layer, and a covering film in sequence. The covering film may be a polyethylene terephthalate film. The thickness of the covering film may be greater than 10 μm and may be less than 100 μm.

[0069] In another embodiment, the temporary protective film may further include a non-adhesive layer disposed on the opposite side of the support film to the adhesive layer. The non-adhesive layer may be a resin layer that is substantially non-adhesive to the adherend at 0 to 270°C. The non-adhesive layer may include a thermoplastic resin, a thermosetting resin (cured material), or a combination of these resins. The non-adhesive layer may further contain a filler (e.g., ceramic powder, glass powder, silver powder, copper powder, resin particles, rubber particles), a coupling agent, etc. The thickness of the non-adhesive layer may be greater than 1 μm and may be less than 10 μm.

[0070] The temporary protective film can be produced, for example, by a method including the steps of forming an adhesive layer by coating a varnish containing an acrylic polymer and a crosslinking agent on a support film and removing the solvent from the coating film.

[0071] Next, a method for manufacturing a semiconductor device using the above-mentioned temporary protective film is described. The method for manufacturing a semiconductor device of one embodiment sequentially comprises: step S1, attaching a temporary protective film to one side of a substrate; step S2, mounting a semiconductor element on the surface of the substrate opposite to the temporary protective film; step S3, sealing the semiconductor element; and step S4, peeling the temporary protective film from the substrate. Below, as an example, a method for manufacturing a semiconductor device (semiconductor device package) in which the substrate is a lead frame is described in more detail.

[0072] Figure 2 FIG. 1 is a cross-sectional view illustrating an embodiment (step S1) of a method for manufacturing a semiconductor device. Figure 2 As shown, a temporary protective film 10 is attached to one surface, that is, the back surface, of a lead frame 11 having a die pad 11a and inner leads 11b. The temporary protective film 10 is attached in a direction in which the adhesive layer of the temporary protective film 10 contacts the lead frame 11.

[0073] The lead frame 11 may be formed of, for example, an iron alloy such as 42 alloy, copper or a copper alloy. The lead frame 11 may include a molded body formed of copper or a copper alloy and a coating layer of palladium, gold, silver or the like covering the surface thereof.

[0074] The temporary protective film 10 has excellent adhesiveness at room temperature (e.g., 25° C.), and thus can be attached to the lead frame 11 at room temperature. The temporary protective film 10 can be attached to the lead frame 11 while being heated and pressurized. In this case, the heating temperature can be 150° C. or higher and 400° C. or lower. The pressure can be 0.5 MPa or higher and 30 MPa or lower. The heating and pressurizing time can be 1 second or higher and 60 seconds or lower.

[0075] Figure 3 FIG. 1 is a cross-sectional view illustrating an embodiment (steps S2 and S3) of a method for manufacturing a semiconductor device. Figure 3 As shown, a semiconductor element 14 is mounted on the surface of the die pad 11a opposite to the temporary protective film 10. The semiconductor element 14 is bonded to the die pad 11a via an adhesive (e.g., silver paste). After the semiconductor element 14 is bonded to the die pad 11a, a reflow connection (CuClip: copper sheet connection, etc.) can be performed at a maximum temperature of 250 to 440°C or 250 to 400°C for 1 to 30 minutes.

[0076] Next, the semiconductor element 14 is connected to the inner lead 11b using the wire 12. The wire 12 may be, for example, a gold wire, a copper wire, or a palladium-coated copper wire. The wire 12 may be bonded to the semiconductor element 14 and the inner lead 11b by ultrasonic and pressing pressure while being heated at 200 to 350°C.

[0077] Next, in step S3, Figure 3 As shown, a sealing layer 13 is formed to seal the semiconductor element 14 and the wire 12. Thus, a temporarily protected sealing molded body 20 having the lead frame 11, the semiconductor element 14 and the sealing layer 13 can be obtained.

[0078] The sealing layer 13 is formed by sealing molding using a sealing material. By sealing molding, a sealing molded body 20 having a plurality of semiconductor elements 14 and the sealing layer 13 sealing these together can be obtained. During the sealing molding, by providing a temporary protective film 10, the sealing material is prevented from being wound around the back side of the lead frame 11.

[0079] The temperature during the formation of the sealing layer 13 (temperature of the sealing material) may be 140 to 200° C. or 160 to 180° C. The pressure during the formation of the sealing layer may be 6 to 15 MPa or 7 to 10 MPa. The sealing molding time may be 1 to 5 minutes or 2 to 3 minutes.

[0080] The sealing material may include, for example, epoxy resins such as cresol novolac epoxy resin, phenol novolac epoxy resin, biphenyl diepoxy resin, and naphthol novolac epoxy resin. The sealing material may include fillers, flame retardants such as bromine compounds, wax components, and the like.

[0081] After the sealing layer 13 is formed (sealing molding), the temporary protective film 10 is peeled off from the lead frame 11 and the sealing layer 13 of the obtained sealing molded body 20. When the sealing layer 13 is cured, the temporary protective film 10 can be peeled off at any time before or after the sealing layer 13 is cured.

[0082] The temperature when peeling off the temporary protective film 10 is not particularly limited, but can be room temperature (e.g., 5 to 35° C.). The temperature can be above the glass transition temperature of the adhesive layer. In this case, the peelability of the temporary protective film 10 relative to the lead frame 11 and the sealing material becomes better. When the Tg of the acrylic polymer in the adhesive layer is, for example, below 5° C. or below 0° C., the Tg of the adhesive layer becomes equal to or below room temperature, and good peelability is easily obtained at room temperature.

[0083] In the case where the lead frame 11 includes a plurality of patterns of die pads 11a and inner leads 11b, the sealing molded body 20 can be divided as needed to obtain a plurality of semiconductor devices each having one semiconductor element. Figure 4 That is, when the lead frame 11 has a plurality of die pads 11a and a semiconductor element 14 is mounted on each of the plurality of die pads 11a, the manufacturing method according to one embodiment may further include a step of peeling the temporary protective film 10 from the sealing molded body 20 and then dividing the sealing molded body 20 to obtain a semiconductor device (semiconductor package) 100 having one die pad 11a and a semiconductor element 14.

[0084] The temporary protective film is in a long strip shape and can be used in a state of being wound around a reel body of a winding core. In this case, the temporary protective film is attached to the adherend while being unwound from the reel body.

[0085] Figure 5 1 is a perspective view showing an embodiment of a reel body. Figure 5 As shown, the reel body 30 involved in one embodiment includes a core 31, a temporary protective film 10 wound on the core 31, and a side plate 32. The width (length in a direction perpendicular to the winding direction) of the core 31 and the temporary protective film 10 can be 1 mm or more, 5 mm or more, or 10 mm or more, and can be 1000 mm or less, 800 mm or less, or 500 mm or less. In another embodiment, the reel body may not have a side plate.

[0086] Example

[0087] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the Examples.

[0088] (Example 1)

[0089] An acrylic polymer A-1 containing 80 mass % of butyl acrylate (BA), 16 mass % of acryloyl morpholine (ACMO), 3 mass % of acrylic acid, and 1 mass % of other monomers (monomers having hydroxyl groups) as monomer units was prepared. 100 parts by mass of the acrylic polymer A-1 and the following formula (B-1):

[0090]

[0091] 10 parts by mass of the crosslinking agent B-1 indicated above was dissolved in cyclohexanone to obtain a varnish for forming an adhesive layer.

[0092] As a support film, a polyimide film (thickness: 25 μm, manufactured by DU PONT-TORAY CO., LTD., product name: Kapton 100EN) was prepared. The obtained varnish was applied to one side of the support film. The coating film on the support film was dried by heating at 90°C for 1.5 minutes and at 260°C for 1.5 minutes to form an adhesive layer with a thickness of 5 μm. Thus, a temporary protective film was obtained.

[0093] (Example 2)

[0094] A temporary protective film was obtained in the same manner as in Example 1 except that acrylic polymer A-2 was used instead of acrylic polymer A-1, wherein the BA content was changed to 86.5 mass % and the ACMO content was changed to 9.5 mass % in the monomer composition of acrylic polymer A-1.

[0095] (Comparative Example 1)

[0096] A temporary protective film was obtained in the same manner as in Example 1 except that acrylic polymer A-3 was used in place of acrylic polymer A-1, wherein the BA content was changed to 90.5 mass % and the ACMO content was changed to 5.5 mass % in the monomer composition of acrylic polymer A-1.

[0097] (Example 3)

[0098] In addition to using the following formula (B-2):

[0099]

[0100] A temporary protective film was obtained in the same manner as in Example 1 except that the crosslinking agent B-2 shown was used instead of the crosslinking agent B-1.

[0101] (Example 4)

[0102] In addition to using the following formula (B-3):

[0103]

[0104] A temporary protective film was obtained in the same manner as in Example 1 except that the crosslinking agent B-3 shown was used instead of the crosslinking agent B-1.

[0105] (Examples 5 to 8)

[0106] A temporary protective film was obtained in the same manner as in Example 1 except that the blending ratio (parts by mass) of the acrylic polymer A-1 and the crosslinking agent B-1 was changed as shown in Table 1.

[0107] (Example 9)

[0108] A temporary protective film was obtained in the same manner as in Example 1 except that the thickness of the adhesive layer was changed to 10 μm.

[0109] (Evaluation of Adhesion Strength)

[0110] (1) After attachment at room temperature

[0111] As adherends, EFTEC64TCu plates (Cu-Fe-P alloy, manufactured by Shinko Electric Industries Co., Ltd.) and CDA194 palladium-plated plates (PPF, manufactured by Shinko Electric Industries Co., Ltd.) were prepared. Each temporary protective film cut into a size of 10 mm × 50 mm was attached to each of these adherends using a hand roller at 25°C and a load of 20 N in the direction in which the adhesive layer was in contact with the adherend, thereby obtaining each attached body. Next, using a dynamometer, each temporary protective film was peeled off at a speed of 50 mm / min at 25°C in a direction 90 degrees relative to the main surface of the lead frame. At this time, the maximum value (N / m) of the load per 10 mm width of the adhesive layer was measured as the adhesive force (90 degree peel strength) after attachment at room temperature. The results are shown in Table 1.

[0112] (2) Adhesion after heating treatment

[0113] Each attached body obtained in the same manner as in (1) above was subjected to a heat treatment at 180°C for 60 minutes and then at 200°C for 60 minutes in an oven under an air atmosphere. Afterwards, the temporary protective film was peeled off at a speed of 50 mm / min at 25°C along a direction 90 degrees relative to the main surface of the lead frame using a dynamometer. At this time, the maximum value (N / m) of the load per 10 mm width of the adhesive layer was measured as the adhesive force (90 degree peel strength) after the heat treatment. The results are shown in Table 1.

[0114] (3) Evaluation of residues

[0115] Each temporary protective film was attached to a CDA194 palladium-plated Cu plate (lead frame, manufactured by Shinko Electric Industries Co., Ltd.) at 25°C and a load of 20N in the direction where the adhesive layer was in contact with the lead frame. The obtained bonded body was heated in an oven under an air atmosphere, changing the conditions to 180°C for 60 minutes and then 200°C for 60 minutes. The surface of the lead frame opposite to the temporary protective film was plasma treated under an argon atmosphere (flow rate: 20 sccm) at 150 W for 15 seconds.

[0116] Using a mold forming machine (manufactured by APIC YAMADA CORPORATION), a sealing layer was formed on the surface of the lead frame on the opposite side of the temporary protective film by a sealing material (product name: GE-300, manufactured by Showa Denko Materials co., Ltd.). The sealing conditions were set to 175°C, 6.8MPa, and 2 minutes. Afterwards, at 25°C, each temporary protective film was peeled off at a speed of 50mm / min in a direction 180° relative to the surface of the lead frame. The state of the adhesive layer remaining on the sealing layer after peeling off the temporary protective film was confirmed. The ratio of the area occupied by the residue of the adhesive layer to the surface area of ​​the sealing layer was determined. According to the ratio of the area occupied by the residue of the adhesive layer, the peelability after sealing molding was evaluated according to the following 5-stage benchmark. The results are shown in Table 1.

[0117] 5: 60~100%

[0118] 4: 40% or more and less than 60%

[0119] 3: 20% or more and less than 40%

[0120] 2: 10% or more and less than 20%

[0121] 1: 0% or more and less than 10%

[0122] (4) Evaluation of appearance

[0123] After each temporary protective film was peeled off in the above (3), it was confirmed whether there was a portion with a different hue on the sealing layer. The appearance after the seal molding was evaluated according to the following criteria based on whether there was a portion with a different hue. The results are shown in Table 1.

[0124] A: There is no part with different hue (almost all black (color of the sealing layer))

[0125] B: There is a part with a different hue (a white linear area on a black surface)

[0126]

[0127] Explanation of symbols

[0128] 1-support film, 2-adhesive layer, 10-temporary protective film, 11-lead frame, 11a-chip pad, 11b-inner lead, 12-wire, 13-sealing layer, 14-semiconductor element, 20-sealed molded body, 100-semiconductor device.

Claims

1. A temporary protective film for semiconductor device manufacturing, comprising: a support film; and An adhesive layer is provided on the support film, The adhesive layer contains: A polymer comprising, as monomer units, alkyl (meth)acrylate, (meth)acryloylmorpholine and a monomer having a crosslinking group; and a crosslinking agent capable of crosslinking with the crosslinkable group, The content of the (meth)acryloylmorpholine is 7% by mass or more based on the total amount of monomer units in the polymer.

2. The temporary protective film according to claim 1, wherein The crosslinkable group is an acidic group, and the crosslinking agent has an epoxy group.

3. The temporary protective film according to claim 2, wherein: The cross-linking agent further has an amino group.

4. The temporary protective film according to any one of claims 1 to 3, wherein The crosslinking agent has a group represented by the following formula (1), 5. A method for manufacturing a semiconductor device, comprising: A step of attaching a temporary protective film to one side of the substrate; A step of mounting a semiconductor element on a surface of the substrate opposite to the temporary protective film; A step of sealing the semiconductor element; and a step of peeling the temporary protective film from the substrate, The temporary protective film comprises: a support film; and An adhesive layer is provided on the support film, The adhesive layer contains: A polymer comprising, as monomer units, alkyl (meth)acrylate, (meth)acryloylmorpholine and a monomer having a crosslinking group; and a crosslinking agent capable of crosslinking with the crosslinkable group, The content of the (meth)acryloylmorpholine is 7% by mass or more based on the total amount of monomer units in the polymer.

6. The manufacturing method according to claim 5, wherein: The crosslinkable group is an acidic group, and the crosslinking agent has an epoxy group.

7. The manufacturing method according to claim 6, wherein: The cross-linking agent further has an amino group.

8. The manufacturing method according to any one of claims 5 to 7, wherein: The crosslinking agent has a group represented by the following formula (1),

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