KR20230052946A - Manufacturing method of release film and electronic component device - Google Patents

Abstract

A release film having an elongation at 170°C of 500% or more.

Description

Manufacturing method of release film and electronic component device

The present disclosure relates to a method for manufacturing a release film and an electronic component device.

BACKGROUND ART [0002] In recent years, as thinning of electronic devices, particularly mobile phones, has progressed, further thinning of electronic parts such as semiconductor elements has been demanded. Also, from the viewpoint of improving heat dissipation, instead of over-molding that covers the entire electronic component with encapsulating resin, exposed die molding that exposes a part of the surface of the electronic component is used. Cases are increasing.

When an electronic component is sealed so that a part of the electronic component is exposed, it is necessary to prevent leakage (flash burr) of the sealing material to the exposed portion of the electronic component. Therefore, sealing is performed in a state where a film (release film) having releasability is attached to the exposed portion of the electronic component, and then the release film is peeled off to expose the surface of the electronic component.

As such a release film, for example, in Japanese Laid-open Patent Publication No. 2006-49850, a laminated film obtained by laminating a film made of a fluororesin on at least one side of a base film made of a stretched polyester resin film is are listed.

Japanese Unexamined Patent Publication No. 2006-49850

In recent years, the shape of the adhered surface of a release film tends to become complicated, and improvement in followability of the release film to the adhered surface (ie, the property of deforming to conform to the shape of the adhered surface) has been demanded. For example, there is a demand for development of a release film suitable for the purpose of exposing terminals in a technique of encapsulating a plurality of semiconductor packages on a substrate and encapsulating them (thick film encapsulation).

In view of the above circumstances, one aspect of the present disclosure makes it a subject to provide a release film excellent in followability to an adherend surface. Another aspect of this indication makes it a subject to provide the manufacturing method of the electronic component apparatus using this release film.

Means for solving the above problems include the following embodiments.

<1> A release film having an elongation at 170°C of 500% or more.

<2> The release film according to <1>, wherein the elastic modulus at 170°C is 65 MPa or more.

<3> The release film according to <1> or <2>, wherein the tack force at 23°C on the surface of the adherend surface is 0.1 gf or more.

<4> The release film according to any one of <1> to <3>, comprising a base material layer and a release layer.

The release film as described in <4> in which the <5> said base material layer contains polybutylene terephthalate.

<6> The release film according to <4> or <5>, in which the release layer contains an adhesive.

<7> The release film according to any one of <4> to <6>, wherein the release layer has a thickness of 1 µm or more.

<8> The release film according to any one of <1> to <7> for temporarily protecting at least a part of the surface of an object.

<9> The release film according to any one of <1> to <8>, for exposure molding.

<10> A step of sealing the periphery of an electronic component in a state in which the release film according to any one of <1> to <9> is in contact with at least a part of the surface of the electronic component, and peeling the release film from the electronic component A method for manufacturing an electronic component device comprising the steps of:

According to one aspect of the present disclosure, a release film having excellent followability to an adherend surface is provided. According to another aspect of this indication, the manufacturing method of the electronic component apparatus using this release film is provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a plan view which shows the shape of the test piece used for measuring the elongation and elastic modulus of a release film.
2 is a cross-sectional view schematically showing the configuration of a release film.

Hereinafter, the form for implementing this indication is demonstrated in detail. However, the present disclosure is not limited to the following embodiments. In the following embodiments, the constituent elements (including element steps and the like) are not essential unless otherwise specified. The same applies to numerical values and their ranges, and the present disclosure is not limited.

In this specification, the word "process" includes a process independent from other processes, as well as a process that cannot be clearly distinguished from other processes, provided that the purpose of the process is achieved.

Numerical ranges expressed using “to” in this specification include the numerical values described before and after “to” as the minimum and maximum values, respectively.

In the numerical ranges described stepwise in this specification, the upper limit or lower limit of one numerical range may be replaced with the upper limit or lower limit of another stepwise numerical range. In addition, in the numerical range described in this specification, you may replace the upper limit value or the lower limit value of the numerical range with the value shown in the Example.

In the present specification, the content rate or content of each component in the composition is, when there are plural types of substances corresponding to each component in the composition, the content rate or content of the total of the plural types of substances present in the composition, unless otherwise specified. means

In the present specification, the particle diameter of each component in the composition means a value for a mixture of the plurality of types of particles present in the composition, unless otherwise specified, when there are plural types of particles corresponding to each component in the composition. do.

In this specification, the word "layer" includes a case where the layer is formed in the entire region as well as a case where it is formed only in a part of the region when the region where the layer exists is observed.

In this specification, the release film or the thickness of each layer constituting the release film can be measured by a known method. For example, it may be measured using a dial gauge or the like, or may be measured from a cross-sectional image of a release film. Alternatively, the material constituting the layer may be removed using a solvent or the like, and it may be calculated from the mass before and after removal, the density of the material, the area of the layer, and the like. When the thickness of the layer is not constant, the arithmetic mean value of the values measured at arbitrary five points is taken as the thickness of the layer.

In this specification, "(meth)acryl" means any one or both of acryl and methacryl, and "(meth)acrylate" means any one or both of acrylate and methacrylate.

In the present disclosure, when embodiments are described with reference to the drawings, the configuration of the embodiments is not limited to those shown in the drawings. In addition, the sizes of members in each drawing are conceptual, and the relative relationship between the sizes of members is not limited thereto.

<release film>

The release film of the present disclosure is a release film having an elongation at 170°C of 500% or more.

The release film has an elongation of 500% or more at 170°C. Accordingly, it has excellent extensibility under general temperature conditions in which the process of attaching the release film to the adherend surface is performed, and exhibits excellent trackability to the adherend surface. Thereby, even when the shape of the adherend surface is complicated, for example, penetration of the encapsulant into the portion to which the release film is attached can be effectively suppressed.

The elongation at 170°C of the release film is 500% or more, preferably 550% or more, more preferably 600% or more, and still more preferably 700% or more.

From the viewpoint of ease of peeling, the elongation at 170°C of the release film may be 1300% or less, 1200% or less, 1000% or less, or 800% or less.

The release film preferably has a modulus of elasticity at 170°C of 65 MPa or more, more preferably 70 MPa or more, and still more preferably 75 MPa or more.

When the modulus of elasticity at 170°C of the release film is 65 MPa or more, the release film has an appropriate diameter and the workability when adhering to the adherend surface is good.

From the viewpoint of followability to the adhered surface, the modulus of elasticity at 170°C of the release film may be 150 MPa or less, 120 MPa or less, or 100 MPa or less.

The release film may have an elongation at 150°C of 500% or more, 550% or more, or 700% or more.

If the elongation at 150°C of the release film is 500% or more, excellent adhesion is exhibited even when the release film is adhered to the adherend surface at a low temperature.

From the viewpoint of ease of peeling, the elongation at 150°C of the release film may be 1300% or less, 1200% or less, 1000% or less, or 800% or less.

The release film may have an elastic modulus at 150°C of 65 MPa or more, 70 MPa or more, or 75 MPa or more.

When the modulus of elasticity at 150°C of the release film is 65 MPa or more, workability is good even when the release film is adhered to the adherend surface at a low temperature.

From the viewpoint of followability to the adhered surface, the modulus of elasticity at 150°C of the release film may be 150 MPa or less, 120 MPa or less, or 100 MPa or less.

In the present disclosure, the elongation (%) of the release film is measured as follows.

First, a test piece (unit of length: mm) having a shape as shown in FIG. 1 is produced using a release film. The shape of the test piece is not limited to the shape shown in FIG. 1 as long as it has a portion having a width of 10 mm and ensuring a distance between chucks.

Hold the both ends of the test piece with the holding tool (chuck) of the tensile tester and conduct a tension test. The position to hold the test piece is the part where the width of the test piece is 10 mm, and the distance between chucks is 15 mm. The measurement was performed under a predetermined temperature condition, and the tensile speed was 500 mm/min.

From the distance A (15 mm) between chucks of the test piece before the tension test and the distance B between chucks when the test piece is cut, the elongation is calculated by the following formula.

[Formula 1]

Elongation (%) = (B-A)/A×100

For the measurement of the elongation of the release film, for example, "Tensilon Tensile Tester RTA-100 Type" manufactured by Orientec Co., Ltd., "Tensilon Universal Testing Machine RTG-1210" manufactured by A&D Co., Ltd., or It is a tester similar to this, and uses one with a gripping tool.

The modulus of elasticity (MPa) of the release film is calculated from the inclination of the tangent line in the stress-strain diagram by pulling the test piece in the same way as in the measurement of the elongation. Specifically, from the stress (kgf) per cross-sectional area (cm ² ) over the test piece, it is calculated by the following formula.

[Formula 2]

Modulus of elasticity (MPa) = (stress/area) × 0.098

From the viewpoint of adhesion to the adherend surface, the tack force at 23°C of the adherend surface side of the release film is preferably 0.1 gf or more, more preferably 0.2 gf or more, and still more preferably 0.5 gf or more.

From the standpoint of releasability from the adherend surface, the tack force at 23°C on the surface of the adherend surface of the release film is preferably 40 gf or less, more preferably 35 gf or less, and still more preferably 30 gf or less.

In the present disclosure, the tack force (gf) of the release film is measured using a tact tester (for example, manufactured by Lesca Co.) and a probe having a diameter of 5 mm, at 23 ° C., a load before measurement of 10 gf, and a load time before measurement of 1 second. It is measured under conditions of a rising speed of 120 mm/min.

The release film may have a base material layer and a release layer, and may further have a conductive layer.

An example of the structure of a release film having a substrate layer, a release layer, and a conductive layer is schematically shown in FIG. 2 . The release film 40 shown in FIG. 2 is equipped with the base material layer 10, the release layer 20, and the conductive layer 30 arrange|positioned between the base material layer 10 and the release layer 20.

When the release film has a substrate layer, required strength is imparted to the release film, and physical properties such as elongation and elastic modulus can be adjusted by appropriately selecting the material.

When the release film has a release layer, the release film can be easily peeled off from the adherend surface.

Since the release film has a conductive layer, discharge at the time of peeling the release film is suppressed, and occurrence of electrostatic breakdown or the like of the electronic component is effectively suppressed.

The thickness of the entire release film is not particularly limited and may be set according to desired physical properties (elongation, modulus of elasticity, etc.). For example, it may be 30 μm to 300 μm, 35 μm to 250 μm, or 40 μm to 200 μm.

(base layer)

The material of the substrate layer is not particularly limited as long as the elongation at 170°C of the release film using the same is 500% or more.

Examples include polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; resins such as polyimides, polyamides, polyester ethers, polyamideimides, fluorine-containing resins, and thermoplastic elastomers.

From the viewpoint of ensuring elongation at 170°C, the substrate layer preferably contains polybutylene terephthalate.

The substrate layer may contain only polybutylene terephthalate as a resin, or may contain resins other than polybutylene terephthalate and polybutylene terephthalate. For example, the substrate layer may also contain polybutylene terephthalate and polyethylene terephthalate.

When the substrate layer contains polybutylene terephthalate and polyethylene terephthalate, effects such as increasing the elastic modulus while maintaining a high elongation can be expected, for example.

When the substrate layer contains polybutylene terephthalate and resin other than polybutylene terephthalate, the ratio of polybutylene terephthalate may be 50% by mass or more, 60% by mass or more, or 70% by mass of the entire resin. It may be more than 80 mass % or more. Moreover, it may be 99 mass % or less of the whole resin, and 95 mass % or less may be sufficient.

From the viewpoint of sufficiently securing the elongation at 170°C, the substrate layer is preferably non-stretched (not subjected to stretching treatment).

The thickness of the substrate layer is not particularly limited, and is preferably 10 μm or more, more preferably 20 μm or more, and still more preferably 30 μm or more. When the thickness of the substrate layer is 10 μm or more, the release sheet tends to be difficult to tear and handleability is excellent.

The thickness of the substrate layer is preferably 300 μm or less, more preferably 200 μm or less, and still more preferably 100 μm. When the thickness of the substrate layer is 300 μm or less, there is a tendency for sufficient followability to the adhered surface to be obtained.

The substrate layer may be composed of only one layer, or may be composed of two or more layers. As a method of obtaining a substrate layer composed of two or more layers, a method of extruding and producing the material of each layer by a co-extrusion method, a method of laminating two or more films, and the like are exemplified.

When a release film contains a conductive layer, the process for improving the adhesiveness with respect to a conductive layer may be given to the surface of the base material layer on the side where the conductive layer is provided. Examples of the treatment method include surface treatment such as corona treatment and plasma treatment, application of a primer (primer), and the like.

If necessary, a back surface treatment agent for adjusting the unwinding property of the release film from the roll may be provided on the back surface of the substrate layer (the surface opposite to the side adhered to the adherend surface). Examples of the back surface treatment agent include silicone resins, fluorine-containing resins, polyvinyl alcohol, and resins having an alkyl group. If necessary, these back surface treatment agents may be denatured. A back surface treatment agent may use only 1 type, or may use 2 or more types together.

(release layer)

The material of the release layer is not particularly limited and may be selected according to desired properties of the release film (adhesion to the adherend surface, peelability, etc.). From the viewpoint of adhesion to the adhered surface, the release layer preferably has adhesiveness. As a method of imparting adhesiveness to the release layer, a method of making the release layer contain an adhesive is exemplified.

The type of adhesive is not particularly limited, and may be selected in consideration of adhesiveness, releasability, heat resistance, and the like. Specifically, an acrylic pressure sensitive adhesive, a silicone pressure sensitive adhesive and a urethane pressure sensitive adhesive are preferable, and an acrylic pressure sensitive adhesive is more preferable. 1 type may be sufficient as the adhesive contained in a release layer, or 2 or more types may be sufficient as it.

The acrylic pressure-sensitive adhesive is a monomer having a low glass transition temperature (Tg) such as butyl acrylate, ethyl acrylate, and 2-ethylhexyl acrylate as main monomers (for example, -20 ° C or lower), (meth)acrylic acid, hydroxyethyl It is a copolymer obtained by copolymerizing a monomer having a functional group such as (meth)acrylate, hydroxyethyl (meth)acrylate, (meth)acrylamide, and (meth)acrylonitrile (hereinafter also referred to as an acrylic copolymer). desirable. The said "glass transition temperature" is the glass transition temperature of the homopolymer obtained using the corresponding monomer.

The acrylic copolymer may be a crosslinking type acrylic copolymer. A crosslinking type acrylic copolymer can be synthesized by crosslinking a monomer that is a raw material of the acrylic copolymer using a crosslinking agent. Examples of the crosslinking agent used in the synthesis of the crosslinking type acrylic copolymer include known crosslinking agents such as isocyanate compounds, melamine compounds, and epoxy compounds. In addition, in order to form a network structure that spreads gently in the acrylic pressure-sensitive adhesive, it is more preferable that the crosslinking agent is a polyfunctional crosslinking agent such as trifunctional or tetrafunctional.

The release layer may also contain an anchoring enhancer, a crosslinking accelerator, a filler, a colorant and the like as needed. For example, when a mold release layer contains a filler, the external surface (surface opposite to a conductive layer) of a mold release layer is roughened, and the peelability to an electronic component improves, etc. effect is acquired.

The material of the filler is not particularly limited, and may be an organic material such as a resin, an inorganic material such as a metal or a metal oxide, or a combination of an organic material and an inorganic material. In addition, only 1 type may be sufficient as the filler contained in a mold release layer, and 2 or more types may be sufficient as it. The volume average particle diameter of the filler is not particularly limited. For example, it can select from the range of 1 micrometer - 20 micrometers. In the present specification, the volume average particle diameter of the filler is the particle diameter (D50) when the accumulation from the small diameter side is 50% in the volume-based particle size distribution measured by the laser diffraction method.

From the viewpoint of affinity with the pressure-sensitive adhesive contained in the release layer, it is preferable that the filler is a resin particle. Examples of the resin constituting the resin particles include acrylic resins, olefin resins, styrene resins, acrylonitrile resins, and silicone resins. From the viewpoint of suppressing residue on the surface of the semiconductor package after molding, an acrylic resin is preferable.

The thickness of the release layer is not particularly limited, and is preferably 0.1 μm or more, and more preferably 1 μm or more. When the thickness of the release layer is 0.1 μm or more, the adhesive strength to the electronic component is sufficiently obtained, and penetration of the encapsulant is effectively suppressed.

The thickness of the release layer may be 100 μm or less, 50 μm or less, or 10 μm or less. When the thickness of the release layer is 100 μm or less, heat shrinkage stress at the time of thermal curing of the release layer is not easily generated, and flatness of the release film is easily maintained. In addition, when the release film has a conductive layer, the distance from the conductive layer on the surface of the release layer is not too far, the surface resistivity is maintained low, and electrostatic breakdown of electronic components is effectively suppressed.

Considering the ease of formation of the release layer (applicability, etc.), securing of adhesive strength, securing of antistatic function, etc., the thickness of the release layer is more preferably 3 μm to 50 μm.

(conductive layer)

The structure of the conductive layer is not particularly limited as long as it can increase the conductivity of the release film and suppress charging. For example, a layer containing a conductive material such as an antistatic agent, a conductive polymer material, or a metal may be used.

As the antistatic agent contained in the conductive layer, cationic antistatic agents having cationic groups such as quaternary ammonium salts, pyridium salts, primary to tertiary amino groups, and anionic groups such as sulfonate groups, sulfuric acid ester bases, and phosphoric acid ester bases, Anionic antistatic agents having an antistatic agent, amphoteric antistatic agents such as amino acids and amino acid sulfate esters, nonionic antistatic agents having nonionic groups such as amino alcohols, glycerin, and polyethylene glycol, and these antistatic agents with high molecular weight Chemicalized polymeric antistatic agents and the like are exemplified. The antistatic agent may be a combination of a main agent and an auxiliary agent (such as a curing agent).

Examples of the conductive polymer material included in the conductive layer include polymer compounds having polythiophene, polyaniline, polypyrrole, polyacetylene and the like in their skeletons.

Examples of the metal include aluminum, copper, gold, chromium, and tin, and aluminum is preferable from the viewpoint of availability.

The method of forming the conductive layer is not particularly limited. For example, there is a method of laminating a metal foil or the like on one side of a film to be a base layer, a method of applying a conductive layer material to one side of a film to be a base layer by coating, vapor deposition, or the like.

The thickness of the conductive layer is not particularly limited as long as the antistatic effect of the release film is sufficiently obtained. For example, it may be within the range of 0.01 μm to 1 μm.

The release film of the present disclosure can be used for various applications. For example, it can be used to temporarily protect at least a part of the surface of an object. Since the release film of the present disclosure is excellent in followability to the adhered surface, when processing is performed on the periphery of the area to which the release film is attached, the area can be effectively protected under the influence.

In the present disclosure, "temporarily protecting" refers to protecting the portion to which the release film is attached between the time the release film is attached to at least a part of the surface of the object until it is peeled off.

The type of processing performed on the periphery of the area where the release film is applied is not particularly limited. For example, encapsulation with a sealing material, roughening treatment, painting treatment, water repellent treatment, antistatic treatment, and the like are exemplified.

The release film may be used for exposure molding.

<Method of manufacturing electronic component device>

A method of manufacturing an electronic component device of the present disclosure includes a step of sealing the periphery of an electronic component in a state in which the above-described release film is in contact with at least a part of the surface of the electronic component, and a step of peeling the release film from the electronic component. It is a manufacturing method of an electronic component device.

As described above, the release film of the present disclosure has excellent followability to the adhered surface. In this way, penetration of the encapsulant into the exposed portion obtained by peeling the release film from the surface of the electronic component is effectively suppressed.

The type of electronic component used in the method is not particularly limited. For example, a semiconductor element, a capacitor, a terminal, etc. are mentioned.

In the above method, the type of material (encapsulant) for encapsulating the periphery of the electronic component is not particularly limited. For example, there is a resin composition containing an epoxy resin, an acrylic resin, and the like.

[Example]

Below, the release film of this indication is demonstrated based on an Example. However, the present disclosure is not limited to the following examples.

<Example 1>

As the substrate layer, an unstretched polybutylene terephthalate film having a thickness of 50 µm and corona treated on one side was prepared.

On the corona-treated surface of the substrate layer, an antistatic agent described later diluted to 2.5% by mass with a mixed solvent (water/isopropyl alcohol = 1/1 (mass ratio)) was applied, and heated at 100°C for 1 minute to form a conductive layer. formed

On the formed conductive layer, a composition for forming a release layer described later was applied so that the thickness of the release layer was 5 μm, and heated at 100° C. for 1 minute to form a release layer, thereby producing a release film.

The antistatic agent used for production of the release film is a mixture of the following component A (100 parts by mass) and component B (25 parts by mass).

Component A: Cationic antistatic agent which is an acrylic copolymer having a quaternary ammonium salt, trade name "Bondip PA-100 main agent", Konishi Co., Ltd.

Component B: Epoxy-based curing agent, trade name "Bondip PA-100 Curing Agent", Konishi Co., Ltd.

The composition for forming a release layer used in production of a release film includes 100 parts by mass of the following adhesive, 20 parts by mass of a crosslinking agent, 5 parts by mass of a filler, and 34 parts by mass of a mixed solvent (toluene/methylethyl ketone = 8:2 (mass ratio)). It is a mixture of wealth.

Adhesive: acrylic adhesive, trade name "FS-1208", solid content: 45% by mass, Lion Specialty Chemical Co., Ltd., mixture of plural types of methacrylic acid ester monomers

Crosslinking agent: trade name "Duranate E405-80T", solid content: 80% by mass, Asahi Kasei Chemical Co., Ltd., polyisocyanate-based crosslinking agent (hexamethylene diisocyanate crosslinking agent (HMDI), number of isocyanate groups in one molecule: 2 dog

Filler: dispersed particles in cross-linked acrylic, trade name "MX-500", volume average particle diameter: 5 µm, Soken Chemical Co., Ltd.

<Example 2>

As the substrate layer, an unstretched polybutylene terephthalate/polyethylene terephthalate film having a thickness of 50 µm and corona treated on one side was prepared.

The used unstretched polybutylene terephthalate/polyethylene terephthalate film contains 90% by mass of polybutylene terephthalate and 10% by mass of polyethylene terephthalate.

A release film was produced in the same manner as in Example 1 except for using the base material layer described above.

<Example 3>

As the substrate layer, an unstretched polybutylene terephthalate film having a thickness of 100 µm and corona treated on one side was prepared.

On the corona-treated surface of the substrate layer, the same antistatic agent as that used in Example 1 diluted to 2.5% by mass with a mixed solvent (water/isopropyl alcohol = 1/1 (mass ratio)) was applied, and heated at 100°C for 1 minute. It was heated to form a conductive layer.

On the formed conductive layer, the same composition for forming a release layer as used in Example 1 was applied so that the thickness of the release layer was 10 μm, and heated at 100° C. for 1 minute to form a release layer to prepare a release film.

<Comparative Example 1>

A release film was produced in the same manner as in Example 1 except that a stretched polybutylene terephthalate film having a thickness of 50 µm was used as the substrate layer instead of a non-stretched polybutylene terephthalate film having a thickness of 50 µm.

<Evaluation test>

The following evaluation test was done using the produced release film.

(Measurement of elongation and modulus of elasticity)

A test piece as shown in Fig. 1 was prepared using a release film and placed in a chamber heated to 170°C. After 1 minute had elapsed, the above tensile test was conducted in the chamber, and the elongation and elastic modulus at 170°C were measured.

In Example 1, Example 2 and Comparative Example 2, "Tensilon Tensile Tester RTA-100 type" manufactured by Orientec Co., Ltd. was used as a tensile tester.

In Example 3, "Tensilon Universal Testing Machine RTG-1210" manufactured by A&D Co., Ltd. was used as a tensile tester.

(measurement of tackiness)

The tack force at 23°C on the surface of the release layer of the release film was measured by the method described above.

(mold followability)

After attaching the release film to the upper mold of the transfer mold with a depth of 1 mm and fixing in vacuum, the mold was clamped and the encapsulant was transferred molded. The mold temperature was 170°C, the molding pressure was 6.86 MPa (70 kgf/cm ² ), and the molding time was 300 seconds.

If vacuum adsorption is possible and the release sheet can be followed, it is OK, and if the followability is insufficient, and vacuum adsorption leakage occurs, it is set as NG, and the mold followability is evaluated.

(heat resistance)

On a SUS (stainless steel) hot plate heated to 170°C, a resin film for a base material layer cut into an arbitrary size was subjected to a heat treatment for 5 minutes, and adhesion to the hot plate was evaluated. When not attached, it was set as OK, and when attached, it was set as NG. The results are shown in Table 1.

[Table 1]

As shown in the results of Table 1, the release films of Examples 1 to 3 having an elongation at 170°C of 500% or more are adhered to the release film of Comparative Example 1 having an elongation of less than 500% at 170°C. has excellent followability.

As for the indication of international application 2020/031272, the whole is taken in into this specification by reference.

All literatures, patent applications, and technical standards described in this specification are incorporated herein by reference to the same extent as if each document, patent application, and technical standard was specifically incorporated by reference and is incorporated herein by reference.

Claims (10)

A release film having an elongation at 170°C of 500% or more. According to claim 1,
A release film having an elastic modulus at 170°C of 65 MPa or more. According to claim 1 or 2,
A release film having a tack force of 0.1 gf or more at 23°C on the surface on the side of the adherend. According to any one of claims 1 to 3,
A release film comprising a substrate layer and a release layer. According to claim 4,
The release film in which the said base material layer contains polybutylene terephthalate. According to claim 4 or 5,
The release film in which the said release layer contains an adhesive. According to any one of claims 4 to 6,
A release film having a thickness of the release layer of 1 μm or more. According to any one of claims 1 to 7,
A release film for temporarily protecting at least a portion of the surface of an object. According to any one of claims 1 to 8,
Release film for exposure molding. A step of sealing the periphery of an electronic component in a state where the release film according to any one of claims 1 to 9 is in contact with at least a part of the surface of the electronic component; and removing the release film from the electronic component. A method of manufacturing an electronic component device comprising a step of peeling.

Images