Patent ID: 12227379

DESCRIPTION OF EMBODIMENTS

In the following description, suitable embodiments of an adhesive film production apparatus and a reel body according to an aspect of the present disclosure will be described in detail with reference to the drawings.

[Adhesive Film]

First, the configuration of an adhesive film produced by an adhesive film production apparatus will be described.FIG.1is a schematic cross-sectional view illustrating an embodiment of the adhesive film. The adhesive film1shown inFIG.1is, for example, a film that is used for temporary protection of a lead frame in a sealing step of sealing a semiconductor element mounted on the lead frame. In the sealing step, the adhesive film1is stuck to the back surface of the lead frame (surface on the opposite side of the surface where the semiconductor element is formed) and temporarily protects the lead frame while a sealing layer for sealing the semiconductor element is formed. The adhesive film1is peeled off from the back surface of the lead frame after the sealing step is completed.

The adhesive film1is handled, for example, in a reel body state of being wound around a winding core14(seeFIG.3). The adhesive film1may be handled in a state in which the reel body is housed in a packaging bag. In this case, a single reel body may be housed in the packaging bag, or a plurality of reel bodies may be housed in the packaging bag. The packaging bag may be formed by using a resin film or may be formed by using a composite resin film having an aluminum layer. Specific examples of the packaging bag include a bag made of an aluminum-coated plastic. Examples of the material of the resin film include plastic such as polyethylene, polyester, vinyl chloride, and polyethylene terephthalate. The reel body may be housed in the packaging bag, for example, in a vacuum packed state. In the packaging bag, a desiccant may be housed together with the reel body. Regarding the desiccant, for example, silica gel may be mentioned. The package may be further wrapped with a cushioning material. The package may be housed in, for example, a packing box such as corrugated cardboard.

As shown inFIG.1, the adhesive film1is configured to have two layers composed of a base material layer2and an adhesive layer3provided on one surface side of the base material layer2. The width of the adhesive film1is, for example, 50 mm or more. The width of the adhesive film1may be 100 mm or more or may be 200 mm or more. The width of the adhesive film1may be 600 mm or less. The width of the adhesive film1may be, for example, 50 mm or more and 600 mm or less, may be 100 mm or more and 600 mm or less, or may be 200 mm or more and 600 mm or less.

The coefficient of linear expansion at 30° C. to 200° C. on the in-plane direction of the adhesive film1is, for example, 16 ppm/° C. or greater and 20 ppm/° C. or less. The in-plane direction may be, for example, either the MD (Machine Direction) direction or the TD (Transverse Direction) direction. The MD direction is usually the longitudinal direction of the adhesive film1. The TD direction is a direction (width direction) orthogonal to the MD direction. The measurement of the coefficient of linear expansion can be measured by means of a thermomechanical analysis apparatus (for example, manufactured by Seiko Instruments Inc.: SSC5200). The coefficient of linear expansion at 30° C. to 200° C. in the in-plane direction of the adhesive film1can be adjusted by, for example, changing the thickness of the adhesive layer3.

The elastic modulus at 30° C. of the adhesive film1is, for example, 9 GPa or less. The elastic modulus at 30° C. of the adhesive film1may be 8 GPa or less or may be 7 GPa or less. The elastic modulus at 30° C. of the adhesive film1may be 4 GPa or greater or may be 5 GPa or greater. The elastic modulus at 30° C. of the adhesive film1can be measured by using a dynamic viscoelasticity measuring apparatus (for example, manufactured by UBM: Rheogel-E4000). In this case, a specimen obtained by cutting the adhesive film1into a size of, for example, 4 mm×30 mm is mounted on a dynamic viscoelasticity measuring apparatus at a distance between chucks of 20 mm. Then, the elastic modulus at 30° C. of the adhesive film1can be determined by measuring the tensile modulus of the specimen under the conditions of sine waves, a temperature range of 30° C. (constant), and a frequency of 10 Hz.

The base material layer2is composed of a material having heat resistance against the heat in each step of a step of forming an adhesive layer3, a step of assembling a semiconductor package, and the like. Such a material may be, for example, at least one polymer selected from the group consisting of an aromatic polyimide, an aromatic polyamide, an aromatic polyamideimide, an aromatic polysulfone, an aromatic polyethersulfone, polyphenylene sulfide, an aromatic polyether ketone, polyallylate, an aromatic polyether ether ketone, and polyethylene naphthalate.

From the viewpoint of enhancing the heat resistance, the glass transition temperature of the base material layer2may be 200° C. or higher or may be 250° C. or higher. As a result, in the steps where heat is applied, that is, a step of adhering a semiconductor element to a die pad, a wire bonding step, a sealing step, and a step of tearing off the temporary protective film from a molded body, softening of the base material layer2is suppressed, and an enhancement of the operation efficiency can be promoted. Furthermore, the elastic modulus at 230° C. of the base material layer2is higher than the elastic modulus at 230° C. of the adhesive layer3(which will be described below).

It is preferable that the base material layer2has sufficient close adhesiveness to the adhesive layer3. When the base material layer2has sufficient close adhesiveness to the adhesive layer3, for example, at the time of tearing off the adhesive film1from the lead frame and the sealing material at a temperature of 100° C. to 300° C., the occurrence of peeling at the interface between the adhesive layer3and the base material layer2can be suppressed. As a result, the resin remaining on the lead frame and the sealing material can be suppressed.

From the viewpoint of sufficiently having both the heat resistance and the close adhesiveness to the adhesive layer3, the base material layer2may be composed of polyimide. The coefficient of linear expansion at 30° C. to 200° C. of the base material layer2based on polyimide may be 3.0×10−5/° C. or less, may be 2.5×10−5/° C. or less, or may be 2.0×10−5/° C. or less. The heat shrinkage rate of the base material layer2at the time of heating at 200° C. for 2 hours may be 0.15% or less, may be 0.1% or less, or may be 0.05% or less.

The material that constitutes the base material layer2is not limited to the above-described resin and can also be selected from the group consisting of copper, aluminum, stainless steel, and nickel. When the base material layer2is composed of these metals, it is possible to bring the coefficient of linear expansion of the adhesive film1closer to the coefficient of linear expansion of the lead frame, and the warpage of the lead frame at the time of sticking the adhesive film1to the lead frame can be suitably reduced.

The base material layer2may be subjected to a surface treatment. Examples of the type of the surface treatment include chemical treatments such as an alkali treatment and a silane coupling treatment; physical treatments such as a sand mat treatment; a plasma treatment, and a corona treatment. By applying a surface treatment, the close adhesiveness to the adhesive layer3can be more sufficiently increased.

From the viewpoint of reducing the warpage of a lead frame when the adhesive film1is stuck to the lead frame, the thickness of the base material layer2may be, for example, 100 μm or less, may be 50 μm or less, or may be 25 μm or less. The thickness of the base material layer2may be 5 μm or more or may be 10 μm or more.

The adhesive layer3is composed of, for example, a thermoplastic resin having an amide group (—NHCO—), an ester group (—CO—O—), an imide group (—NR2, provided that each R is —CO—), an ether group (—O—), or a sulfone group (—SO2—). These resins may be thermoplastic resins having an amide group, an ester group, an imide group, or an ether group. Specifically, examples of such a thermoplastic resin include an aromatic polyamide, an aromatic polyester, an aromatic polyimide, an aromatic polyamideimide, an aromatic polyether, an aromatic polyetheramideimide, an aromatic polyetheramide, an aromatic polyesterimide, and an aromatic polyetherimide. From the viewpoints of heat resistance and adhesiveness, the thermoplastic resin may be at least one resin selected from the group consisting of an aromatic polyetheramideimide, an aromatic polyetherimide, and an aromatic polyetheramide.

The above-described resins can all be produced by subjecting a base component such as an aromatic diamine or a bisphenol and an acid component such as a dicarboxylic acid, a tricarboxylic acid, a tetracarboxylic acid, or an aromatic chloride, or reactive derivatives of these to polycondensation. That is, the production of the above-described resins can be carried out by a conventional method that is used for the reaction between an amine and an acid, and there are no particular limitations in the general conditions and the like. For a polycondensation reaction between an aromatic dicarboxylic acid, an aromatic tricarboxylic acid, or reactive derivatives of these and a diamine as well, a conventional method is used.

Regarding the base component used for the synthesis of an aromatic polyetherimide, an aromatic polyetheramideimide, and an aromatic polyetheramide, for example, aromatic diamines having an ether group, such as 2,2-bis[4-(4-aminophenoxy)phenyl]propane, bis[4-(4-aminophenoxy)phenyl]sulfone, 4,4′-diaminodiphenyl ether, bis[4-(4-aminophenoxy)phenyl]ether, and 2,2-bis[4-(4-aminophenoxy)]hexafluoropropane; aromatic diamines that do not have an ether group, such as 4,4′-methylenebis(2,6-diisopropylamine); siloxanediamines such as 1,3-bis(3-aminopropyl)-tetramethyldisiloxane; and α,ω-diaminoalkanes such as 1,12-diaminododecane and 1,6-diaminohexane, can be used.

In the total amount of the base component, the above-described aromatic diamine having an ether group may be used in an amount of 40 mol % to 100 mol % or 50 mol % to 97 mol %, and at least one selected from the aromatic diamine that does not have an ether group, a siloxanediamine, and α,ω-diaminoalkane may be used in an amount of 0 mol % to 60 mol % or 3 mol % to 50 mol %. Specific examples of the base component include: (1) a base component composed of 60 mol % to 89 mol % or 68 mol % to 82 mol % of an aromatic diamine having an ether group, 1 mol % to 10 mol % or 3 mol % to 7 mol % of a siloxanediamine, and 10 mol % to 30 mol % or 15 mol % to 25 mol % of an α,ω-diaminoalkane; (2) a base component composed of 90 mol % to 99 mol % or 93 mol % to 97 mol % of an aromatic diamine having an ether group and 1 mol % to 10 mol % or 3 mol % to 7 mol % of a siloxanediamine; and (3) a base component composed of 40 mol % to 70 mol % or 45 mol % to 60 mol % of an aromatic diamine having an ether group and 30 mol % to 60 mol % or 40 mol % to 55 mol % of an aromatic diamine that does not include an ether group.

Examples of the acid component used for the synthesis of the aromatic polyetherimide, aromatic polyetheramideimide, and aromatic polyetheramide include: (A) mononuclear aromatic tricarboxylic acid anhydrides and mononuclear aromatic tetracarboxylic acid dianhydrides, such as trimellitic anhydride, a reactive derivative of trimellitic anhydride such as trimellitic anhydride chloride, and pyromellitic dianhydride; (B) polynuclear aromatic tetracarboxylic acid dianhydrides such as bisphenol A bistrimellitate dianhydride, oxydiphthalic anhydride; and (C) aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, terephthalic acid chloride, and a reactive derivative of phthalic acid such as isophthalic acid chloride. Among these, an aromatic polyetheramideimide obtainable by reacting 0.95 to 1.05 mol or 0.98 to 1.02 mol of the above-described acid component (A) per 1 mol of the above-described base component (1) or (2), and an aromatic polyetherimide obtainable by reacting 0.95 to 1.05 mol or 0.98 to 1.02 mol of the above-described acid component (B) per 1 mol of the above-described base component (3), can be used.

The adhesive layer3may contain a component other than the above-described resin. Examples of the other component include fillers such as a ceramic powder, a glass powder, a silver powder, a copper powder, resin particles, and rubber particles; an oxidation inhibitor; and a coupling agent. When the adhesive layer3contains a filler as the other component, the content of the filler may be 1 to 30 parts by mass or may be 5 to 15 parts by mass, with respect to 100 parts by mass of the resin.

Regarding the coupling agent, for example, vinylsilane, epoxysilane, aminosilane, mercaptosilane, a titanate, an aluminum chelate, a zircoaluminuate, and the like can be used. The coupling agent may be a silane coupling agent. Regarding the silane coupling agent, coupling agents having organic reactive groups at the ends of vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy) silane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, and the like, and among these, an epoxysilane coupling agent having an epoxy group can be used.

The organic reactive group is a functional group such as an epoxy group, a vinyl group, an amino group, or a mercapto group. The addition of a silane coupling agent provides an effect of enhancing the close adhesiveness of the adhesive layer3to the base material layer2and suppressing the occurrence of peeling at the interface between the base material layer2and the adhesive layer3at the time of peeling at a temperature of 100 to 300° C. When the adhesive layer3contains a coupling agent, the content of the coupling agent may be 1 to 15 parts by mass or may be 2 to 10 parts by mass with respect to 100 parts by mass of the resin.

The thickness of the adhesive layer3is, for example, 20 μm or less. The thickness of the adhesive layer3may be 18 μm or less, 16 μm or less, 14 μm or less, 12 μm or less, 10 μm or less, 9 μm or less, or 8 μm or less. The thickness of the adhesive layer3is, for example, 1 μm or more. The thickness of the adhesive layer3may be 2 μm or more, 3 μm or more, 4 μm or more, 5 μm or more, 6 μm or more, 7 μm or more, or 8 μm or more. The thickness of the adhesive layer3may be 1 μm or more and 20 μm or less, may be 1 μm or more and 15 μm or less, or may be 1 μm or more and 8 μm or less.

When the thickness of the adhesive layer3is 1 μm or more, sufficient adhesiveness can be secured, and at the same time, fall-off of the sealing material at the time of sealing can be suppressed. When the thickness of the adhesive layer3is 20 μm or less, the overall layer thickness of the adhesive film1is suppressed, the cost is suppressed, and in addition to that, the generation of voids at the time of performing a heat treatment at 300° C. or higher can be suppressed. Furthermore, when the thickness of the adhesive layer3is 20 μm or less, an increase in the wettability at the time of a heat treatment can be suppressed. As a result, the adhesive layer3sticking to the lead frame with an excessive adhesive strength can be suppressed, and peelability can be secured.

The ratio of the thickness of the adhesive layer3to the thickness of the base material layer2is, for example, 0.2 or less. The ratio of the thickness of the adhesive layer3to the thickness of the base material layer2may be 0.1 or less or may be 0.05 or less. As a result, the warpage caused by the volume reduction at the time of solvent removal after application of the adhesive layer3on the base material layer2is suppressed, and the workability at the time of sticking the adhesive film1to the lead frame can be enhanced.

The glass transition temperature (Tg) of the adhesive layer3is higher than normal temperature (for example, 25° C.). The glass transition temperature (Tg) of the adhesive layer3may be, for example, 100° C. or higher or may be 150° C. or higher. The glass transition temperature of the adhesive layer3may be, for example, 300° C. or lower or may be 250° C. or lower. In a case where the glass transition temperature of the adhesive layer3is 100° C. or higher, when the adhesive film1is peeled off from the lead frame and the sealing material, peeling at the interface between the base material layer2and the adhesive layer3is suppressed, and the cohesive failure of the adhesive layer3is suppressed.

When the glass transition temperature of the adhesive layer3is 100° C. or higher, remaining of the adhesive layer3to the lead frame and the sealing material can be suppressed. Furthermore, softening of the adhesive layer3by the heat in the wire bonding step can be suppressed, and the occurrence of defective joining of the wire can be reduced. In addition, softening of the adhesive layer3caused by the heat in the sealing step can be suppressed, and the occurrence of inconvenience that the sealing material penetrates between the lead frame and the adhesive layer3can be suppressed. When the glass transition temperature of the adhesive layer3is 300° C. or lower, softening of the adhesive layer3at the time of adhesion is sufficiently suppressed. Furthermore, a sufficient peel strength at a peeling angle of 90° between the adhesive film1and the lead frame at normal temperature (for example, 25° C.) can be secured.

The glass transition temperature of the adhesive layer3can be measured by using a thermomechanical analysis apparatus (manufactured by Seiko Instruments Inc.: SSC5200 type). The measurement conditions can be set to, for example, a tensile mode at a distance between chucks of 10 mm, a temperature range of 30° C. to 300° C., and a rate of temperature increase of 10° C./min.

The 5% weight reduction temperature of the adhesive layer3may be 300° C. or higher, may be 350° C. or higher, or may be 400° C. or higher. When the 5% weight reduction temperature of the adhesive layer3is 300° C. or higher, outgases caused by the heat at the time of sticking the adhesive film1to the lead frame and the heat in the wire bonding step are not likely to be generated, and contamination of the lead frame, the wire, and the like can be suppressed. The 5% weight reduction temperature can be measured by using a differential thermal balance (for example, manufactured by Seiko Instruments Inc.: SSC5200 type). The measurement conditions can be set to, for example, a rate of temperature increase of 10° C./min in an air atmosphere.

The elastic modulus at 230° C. of the adhesive layer3is, for example, 1 MPa or greater. The elastic modulus at 230° C. of the adhesive layer3may be 3 MPa or greater. In the production process for a semiconductor package, the temperature in the wire bonding step (wire bonding temperature) is not particularly limited; however, the temperature is generally about 200 to 260° C. and is approximately 230° C. Therefore, when the elastic modulus at 230° C. of the adhesive layer3is 1 MPa or greater, softening of the adhesive layer3caused by the heat in the wire bonding step is suppressed, and the occurrence of defective joining of the wire can be suppressed. The elastic modulus at 230° C. of the adhesive layer3is, for example, 2000 MPa or less. The elastic modulus at 230° C. of the adhesive layer3may be 1500 MPa or less or may be 1000 MPa or less.

The elastic modulus at 230° C. of the adhesive layer3can be measured by using a dynamic viscoelasticity measuring apparatus (for example, manufactured by UBM: Rheogel-E4000). In this case, the measurement conditions can be set to a tensile mode at a distance between chucks of 20 mm, sine waves, a frequency of 10 Hz, and a rate of temperature increase of 5° C./min.

The method for forming the adhesive layer3on the base material layer2is not particularly limited; however, for example, a method of applying a resin varnish produced by dissolving a resin in a solvent on the surface of the base material layer2and subsequently removing the solvent by performing a heating treatment, can be used. Regarding the solvent, N-methyl-2-pyrrolidone, dimethylacetamide, diethylene glycol dimethyl ether, tetrahydrofuran, cyclohexanone, methyl ethyl ketone, dimethylformamide, and the like can be used. A method of applying a precursor varnish obtained by dissolving a precursor of a resin in a solvent on the surface of the base material layer2and subsequently removing the solvent by performing a heating treatment, can also be used. When the resin that constitutes the adhesive layer3is a polyimide resin, the precursor is, for example, polyamic acid.

The temperature of the heating treatment may be different between the case where a resin varnish is used and the case where a precursor varnish is used. In the case of a resin varnish, the temperature of the heating treatment may be any temperature at which the solvent can be removed. In the case of a precursor varnish, the temperature of the heating treatment may be equal to or higher than the glass transition temperature of the adhesive layer3in order to form a resin from the precursor (for example, imidization).

The method of applying a resin varnish or a precursor varnish on the surface of the base material layer2is not particularly limited; however, for example, roll coating, reverse roll coating, gravure coating, bar coating, comma coating, die coating, or reduced pressure die coating can be used. Furthermore, the resin varnish or the precursor varnish may be applied on the surface of the base material layer2by immersing the base material layer2in the resin varnish or the precursor varnish.

As shown inFIG.2, the adhesive film1may be configured to have three layers by further including a non-adhesive layer4on the other surface side of the base material layer2(opposite surface side of the adhesive layer3). The non-adhesive layer4is a resin layer that substantially does not have adhesiveness (or pressure-sensitive adhesiveness) to the lead frame at 0° C. to 270° C.

For the formation of the non-adhesive layer4, for example, a thermoplastic resin or a thermosetting resin can be used. Regarding the thermoplastic resin, for example, a resin having an amide group, an ester group, an imide group, or an ether group may be mentioned. The thermoplastic resin may be an aromatic polyetheramideimide obtainable by reacting 1 mol of the above-mentioned base component and 0.95 to 1.05 mol or 0.98 to 1.02 mol of the above-mentioned acid component.

Examples of the thermosetting resin include an epoxy resin, a phenol resin, and a bismaleimide resin (for example, a bismaleimide resin having bis(4-maleimidophenyl)methane as a monomer). A thermoplastic resin and a thermosetting resin may be used as a mixture. In the case of using a thermoplastic resin and a thermosetting resin in combination, the amount of the thermosetting resin may be 5 to 100 parts by mass or may be 20 to 70 parts by mass with respect to 100 parts by mass of the thermoplastic resin.

The non-adhesive layer4may contain components other than the above-described resin. Examples of the other components include a filler and a coupling agent. When the non-adhesive layer4contains a filler as the other component, the content of the filler may be 1 to 30 parts by mass or may be 5 to 15 parts by mass with respect to 100 parts by mass of the resin. When the non-adhesive layer4contains a coupling agent as the other component, the content of the coupling agent may be 1 to 20 parts by mass or may be 5 to 15 parts by mass with respect to 100 parts by mass of the resin.

The thickness of the non-adhesive layer4is, for example, 10 μm or less. The thickness of the non-adhesive layer4may be 9 μm or less, 8 μm or less, or 7 μm or less. The thickness of the non-adhesive layer4is, for example, 1 μm or more. The thickness of the non-adhesive layer4may be 2 μm or more, 3 μm or more, 4 μm or more, 5 μm or more, or 6 μm or more. The thickness of the non-adhesive layer4may be, for example, 1 μm or more and 10 μm or less or may be 1 μm or more and 8 μm or less. The ratio of the thickness of the adhesive layer3to the thickness of the non-adhesive layer4may be 1.0 to 2.0 or may be 1.3 to 2.0.

The elastic modulus at 230° C. of the non-adhesive layer4is, for example, 10 MPa or greater. The elastic modulus at 230° C. of the non-adhesive layer4may be 100 MPa or greater or may be 1000 MPa or greater. When the elastic modulus at 230° C. of the non-adhesive layer4is 10 MPa or greater, softening of the non-adhesive layer4in a step where heat is applied, such as a wire bonding step, can be suppressed, and sticking to the mold, jigs, and the like can be prevented. The elastic modulus at 230° C. of the non-adhesive layer4may be 2000 MPa or less or may be 1800 MPa or less. The elastic modulus at 230° C. of the non-adhesive layer4can be measured by a method similar to the case of the elastic modulus at 230° C. of the above-mentioned adhesive layer3.

The peel strength at a peeling angle of 90° between the non-adhesive layer4and the mold as well as the jig at normal temperature (for example, 25° C.) may be less than 5 N/m or may be 1 N/m or less. The measurement of this peel strength is carried out, for example, after pressure-bonding the non-adhesive layer4to a mold made of brass at a temperature of 250° C. and a pressure of 8 MPa for 10 seconds.

The glass transition temperature of the non-adhesive layer4is, for example, 150° C. or higher. The glass transition temperature of the non-adhesive layer4may be 200° C. or higher or may be 250° C. or higher. When the glass transition temperature of the non-adhesive layer4is 150° C. or higher, softening of the non-adhesive layer4in a step of adhering a semiconductor element to a die pad, a wire bonding step, a sealing step, a step of peeling off the adhesive film1from a sealed body, and the like can be suppressed. Furthermore, sticking of the non-adhesive layer4to the mold and jigs can be suppressed. The glass transition temperature of the non-adhesive layer4may be 350° C. or lower or may be 300° C. or lower.

The method for forming the non-adhesive layer4on the base material layer2is not particularly limited; however, as in the case of the above-mentioned adhesive layer3, a method of applying a resin varnish or a precursor varnish on the base material layer2can be employed. When a thermosetting resin is used as a constituent material of the non-adhesive layer4, or when a thermoplastic resin and a thermosetting resin are used in combination, the thermosetting resin can be cured by a heating treatment after application to adjust the elastic modulus of the non-adhesive layer4to 10 MPa or greater. This heating treatment may be carried out simultaneously with removal of the solvent or imidization or may be carried out separately therefrom.

When the non-adhesive layer4such as described above is provided on the base material layer2, the warpage of the adhesive film1caused by the volume reduction of the adhesive layer3can be canceled by the volume reduction of the non-adhesive layer4at the time of solvent removal, and shrinkage of the non-adhesive layer4at the time of imidization of the non-adhesive layer4, curing of the thermosetting resin, and the like.

[Adhesive Film Production Apparatus]

Next, the adhesive film production apparatus used for the production of the adhesive film1will be described in detail.

FIG.3is a schematic perspective view illustrating an embodiment of the adhesive film production apparatus. InFIG.3, the right-to-left direction is designated as the horizontal direction, and the up-to-down direction is designated as the vertical direction. The adhesive film production apparatus11shown in the same diagram is configured to be an apparatus that cuts a plurality of adhesive films1from a raw film B of an adhesive film1and winding each of the cut adhesive films1to form reel bodies R. As shown inFIG.3, the adhesive film production apparatus11includes a feeding roller12, a cutting part13, and a plurality of winding cores14. Here, the production of an adhesive film1having a two-layer configuration as shown inFIG.1will be described as an example.

The feeding roller12is a portion that continuously feeds out the raw film B of the adhesive film1. On the feeding roller12, as shown inFIG.4, the raw film B of the adhesive film1is wound around such that the adhesive layer3faces outward. That is, on the feeding roller12, the raw film B of the adhesive film1is wound around such that the adhesive layer3bends in an arc. The raw film B of the adhesive film1continuously paid out from the feeding roller12is horizontally conveyed toward the cutting part13at a predetermined speed.

The cutting part13is a portion that cuts out a plurality of adhesive films1at a predetermined width from the raw film B of the adhesive film1. As shown inFIG.5, the cutting part13has an upper shaft16and a lower shaft17disposed as a pair disposed up and down with the raw film B interposed therebetween; a plurality of disc-shaped upper blades18provided on the upper shaft16; and a plurality of disc-shaped lower blades19provided on the lower shaft17. In the embodiment ofFIG.5, the upper blades18face the adhesive layer3, and the lower blades19face the base material layer2. The upper blades18and the lower blades19are in a state in which, for example, the side surfaces of the blade tips are in sliding contact with each other, and the raw film B is cut by a shear cutting method. The widths of the plurality of adhesive films1cut by the cutting part13are adjusted by changing the distances in the axial direction between the upper blades18and the lower blades19. In the present embodiment, a plurality of adhesive films1having different widths are cut out from the raw film B of the adhesive film1by the cutting part13.

The plurality of winding cores14is a portion on which each of the plurality of adhesive films1is wound. On the winding core14, the adhesive film1is wound such that the feeding roller12and the adhesive layer3face outward. The winding cores14may be classified into the case where an adhesive film1having a two-layer configuration as shown inFIG.1is wound, and the case where an adhesive film1having a three-layer configuration as shown inFIG.2is wound. The plurality of winding cores14have a first winding core14A positioned on a first shaft G1and a second winding core14B positioned on a second shaft G2. The first shaft G1and the second shaft G2are positioned at positions that are at least shifted from each other in the horizontal direction, and the first winding core14A and the second winding core14B are alternately disposed in the axial directions.

Here, in the conveyance path of the adhesive film1traveling from the cutting part13toward the winding cores14, the number of times of the adhesive layer3of the adhesive film1bending in a convex manner is equal to or more than the number of times of the adhesive layer3bending in a concave manner. In the form shown inFIG.3, the first shaft G1on which the first winding core14A is positioned is disposed such that the conveyance direction of the adhesive film1traveling from the cutting part13toward the first winding core14A is maintained horizontally similarly to the conveyance direction of the raw film B. On the other hand, the second shaft G2on which the second winding core14B is disposed below the first shaft G1such that, as shown inFIG.3andFIG.5, the adhesive layer3of the adhesive film1traveling from the cutting part13toward the second winding core14B bends in a convex manner. As the result, the adhesive film1traveling from the cutting part13toward the first winding core14A is wound by the first winding core14A such that the adhesive layer3bends neither in a convex manner nor in a concave manner, and the adhesive film1traveling from the cutting part13toward the second winding core14B is wound by the second winding core14B such that the adhesive layer3bends only in a convex manner.

Furthermore, each of the first winding core14A and the second winding core14B has a width W2larger than a width W1of the adhesive film1as an object of winding, as shown inFIG.6. As a result, in a reel body R obtained by winding the adhesive film1on each of the first winding core14A and the second winding core14B, an edge part14aof the winding core14protrudes from a side surface21aof a rolled body21of the adhesive film1. As an example, when the width W1of the adhesive film1as an object of winding is 50 mm or more and less than 55 mm, the width W2of the winding core14for winding this adhesive film can be set to 55 mm. Furthermore, in the example ofFIG.6, the central position in the axial direction of the winding core14is in a shifted state with respect to the central position in the width direction of the adhesive film1. As a result, in the reel body R, the edge part14aof the winding core14protrudes only from one side surface21ain the rolled body21of the adhesive film1, and the other side surface21ais flush with the edge part14aof the winding core14.

Winding tension is applied to the raw film B and the plurality of adhesive films1extending from the feeding roller12through the cutting part13to the winding cores14. For the impartment of the winding tension to the raw film B and the plurality of adhesive films1, tension rollers may be used, or an adjustment mechanism for adjusting the axial positions of the feeding roller12and the winding cores14may be used. The winding tension to be applied to the raw film B and the plurality of adhesive films1is not particularly limited; however, for example, the winding tension is 60 N/m or more. The winding tension may be 70 N/m or more or may be 80 N/m or more. The winding tension is, for example, 150 N/m or less. The winding tension may be 140 N/m or less or may be 130 N/m or less.

[Method for Producing Adhesive Film]

FIG.7is a flow chart showing an embodiment of a method for producing an adhesive film. In the present embodiment, the method for producing an adhesive film is carried out by using the above-described adhesive film production apparatus11. In this method for producing an adhesive film, first, the raw film B of the adhesive film1is continuously paid out from the feeding roller (step S01: feeding step). In the feeding step, the raw film B of the adhesive film1is wound around the feeding roller12such that the adhesive layer3faces outward. That is, the raw film B of the adhesive film1is wound around the feeding roller12such that the adhesive layer3bends in a convex manner. Then, the raw film B of the adhesive film1continuously paid out from the feeding roller12is conveyed horizontally toward the cutting part13at a predetermined speed.

Next, the raw film B of the adhesive film1is cut out into a plurality of adhesive films1having predetermined widths by the cutting part13(step S02: cutting step). In the cutting step, a plurality of adhesive films1having different widths are cut out from the raw film B of the adhesive film1by the cutting part13.

After the plurality of adhesive films1are cut out, each of these adhesive films1is wound on each of a plurality of winding cores14(step S03: winding step). In the winding step, the adhesive film1traveling from the cutting part13toward the second winding core14B is conveyed such that the adhesive layer3bends in a convex manner and then wound. Furthermore, at the time of winding the adhesive film1on each of the first winding core14A and the second winding core14B, the central position in the axial direction of the winding core14is disposed to be shifted with respect to the central position in the width direction of the adhesive film1. As a result, the reel body R in which the adhesive film1is wound on each of the first winding core14A and the second winding core14B is in a state in which the edge part14aof the winding core14protrudes from one side surface21aof the rolled body21of the adhesive film1.

[Operating Effect]

As described above, in the adhesive film production apparatus11, each of a plurality of winding cores14for winding an adhesive film1has a width larger than the width of the adhesive film1as an object of winding. As a result, winding of an adhesive film1having a smaller width than the winding core14can be carried out by using winding cores14having the same width. Therefore, in this adhesive film production apparatus11, it is possible to reduce the type of winding cores14to be prepared, and the production cost for the reel bodies R can be reduced. Furthermore, since the edge part14aof the winding core14protrudes from the adhesive film1as an object of winding, on the occasion of using an adhesive film1wound around a winding core14, alignment of the adhesive film1is made easier by utilizing the protruding portion of the winding core14.

Furthermore, in the adhesive film production apparatus11, each of the plurality of winding cores14is disposed such that the edge part14aof this winding core14protrudes only on one side in the axial direction from the adhesive film1as an object of winding. In this case, on the occasion of using an adhesive film1wound around a winding core14, for example, alignment of the adhesive film1at the time of mounting the reel body R on an apparatus on the side of use is made much easier.

Modification Example

The present disclosure is not limited to the above-described embodiments.FIG.8is a schematic perspective view illustrating another embodiment of the adhesive film production apparatus. In the example ofFIG.3, the raw film B continuously paid out from the feeding roller12is conveyed in the horizontal direction toward the cutting part13; however, as in the case of example ofFIG.8, a roller31that applies tension to the raw film B may be disposed between the feeding roller12and the cutting part13, and the raw film B may be caused to bend in a convex manner by means of this roller31. It is also acceptable to dispose a plurality of rollers similar to the roller31and cause the raw film B between the feeding roller12and the cutting part13to bend multiple times in a convex manner and in a concave manner. In this case, in the conveyance path of the raw film B traveling from the feeding roller12toward the cutting part13, the number of times of the adhesive layer3of the raw film B bending in a convex manner may be equal to or more than the number of times of the adhesive layer3bending in a concave manner. When the raw film B is caused to bend multiple times, the final bending (bending on the side closest to the cutting part13) may be bending in a convex manner.

Furthermore, in the example ofFIG.3, only the adhesive layer3of the adhesive films1traveling from the cutting part13toward the second winding cores14B bends in an arc; however, as in the case of the example ofFIG.8, a roller32that applies winding tension to the adhesive films1may be disposed between the cutting part13and the winding cores14, and the adhesive films1may be caused to bend in a convex manner by means of this roller32. It is also acceptable to dispose a plurality of rollers similar to the roller32and cause adhesive films1between the cutting part13and the winding cores14to bend multiple times in a convex manner and in a concave manner. In this case, in the conveyance path of the adhesive film1traveling from the cutting part13toward the winding core14, the number of times of the adhesive layer3of the adhesive film1bending in a convex manner may be equal to or more than the number of times of the adhesive layer3bending in a concave manner. When the adhesive film1is caused to bend multiple times, the final bending (bending on the side closest to the winding core14) may be bending in a convex manner.

In the example ofFIG.8, the first shaft G1on which the first winding core14A is positioned and the second shaft G2on which the second winding core14B is positioned are positioned at the same position in the vertical direction. The first winding core14A is disposed such that the conveyance direction of the adhesive film1traveling from the cutting part13toward the first winding core14A bends at an approximately right angle with respect to the roller32, and the second winding core14B is disposed such that the conveyance direction of the adhesive film1traveling from the cutting part13toward the second winding core14B bends at an acute angle with respect to the roller32. As the result, each of the adhesive film1traveling from the cutting part13toward the first winding core14A and the adhesive film1traveling from the cutting part13toward the second winding core14B is such that the adhesive layer3bends only in a convex manner and is wound by a winding core14.

Furthermore, for example, in the example ofFIG.6, the edge part14aof the winding core14protrudes only from one side surface21ain the rolled body21of the adhesive film1, and the other side surface21ais flush with the edge part14aof the winding core14; however, the edge parts14aof the winding core14may respectively protrude from one side surface21aand the other side surface21ain the rolled body21of the adhesive film1. That is, the edge part14aof the winding core14may protrude on both sides in the axial direction from the side surfaces21aof the rolled body21of the adhesive film1.

In this case, in the rolled body21of the adhesive film1, the amount of protrusion of the edge part14aof the winding core14from one side surface21aand the amount of protrusion of the edge part14aof the winding core14from the other side surface21amay be equal. Furthermore, the amount of protrusion of the edge part14aof the winding core14from one side surface21ain the rolled body21of the adhesive film1may be larger than the amount of protrusion of the edge part14aof the winding core14from the other side surface21a. In such a configuration as well, when an adhesive film1wound around a winding core14is used, alignment of the adhesive film1is made much easier. The ratio of the amount of protrusion of the edge part14aof the winding core14from one side surface21awith respect to the amount of protrusion of the edge part14aof the winding core14from the other side surface21amay be, for example, 0.02 to 5.00 or may be 0.04 to 3.00.

REFERENCE SIGNS LIST

1: adhesive film,2: base material layer,3: adhesive layer,11: adhesive film production apparatus,12: feeding roller,13: cutting part,14: winding core,14a: edge part, B: raw film, R: reel body, W1: width of adhesive film, W2: width of winding core.