JP2017088759A - Adhesive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive sheet good in detachability of a release material during use.SOLUTION: There is provided an adhesive sheet 1 containing a first release material 2, a resin layer 3 and a second release material 4 laminated in this order, wherein the resin layer 3 contains a thermosetting resin composition and there is difference between release force P1 of the first release material 2 to the resin layer 3 and release force P2 of the second release material 4 to the resin layer 3. There is provide the adhesive sheet 1 having a ratio of the release force P2 to the P1 (P2/P) of 0.02≤P2/P1<1 or 1<P2/P1≤50.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an adhesive sheet.

  Conventionally, an adhesive sheet using a resin composition for an adhesive layer is known. For example, in Patent Document 1, a support such as polyethylene terephthalate, a resin composition layer formed on the support, and a protective film such as a polypropylene film that protects the resin composition layer are laminated in this order. An adhesive film is disclosed. In Patent Document 1, the protective film is also a release material that is peeled off before the lamination of the adhesive film, and the support is also a release material that is peeled off after the lamination.

Japanese Patent No. 5195454

  In such an adhesive sheet, there may be a problem that the resin composition layer is broken when the release material is peeled off during use.

  An object of this invention is to provide the adhesive sheet with the favorable peelability of the peeling material at the time of use.

  According to one aspect of the present invention, an adhesive sheet, wherein a first release material, a resin layer, and a second release material are laminated in this order, the resin layer includes a thermosetting resin composition, There is provided an adhesive sheet having a difference between a peeling force P1 of the first release material to the resin layer and a peel force P2 of the second release material to the resin layer.

  In the adhesive sheet according to one aspect of the present invention, the ratio (P2 / P1) of the peel force P2 of the second release material to the peel force P1 of the first release material is 0.02 ≦ P2 / P1 <1 or 1 <. It is preferable that P2 / P1 ≦ 50.

  The adhesive sheet according to one embodiment of the present invention is preferably for semiconductor encapsulation.

  ADVANTAGE OF THE INVENTION According to this invention, the adhesive sheet with favorable peelability of the peeling material at the time of use can be provided.

It is a section schematic diagram of the adhesive sheet for semiconductor sealing concerning a first embodiment.

[First embodiment]
The case where the adhesive sheet of this invention is an adhesive sheet for semiconductor sealing is demonstrated below. In the semiconductor sealing adhesive sheet of this embodiment, the resin layer is a sealing resin layer.

[Semiconductor sealing adhesive sheet]
FIG. 1 shows a schematic cross-sectional view of a semiconductor sealing adhesive sheet 1 of the present embodiment.
The adhesive sheet 1 for semiconductor sealing of this embodiment is a sheet in which a first release material 2, a sealing resin layer 3, and a second release material 4 are laminated in this order.

(First release material and second release material)
In this embodiment, there is a difference between the peeling force P1 of the first release material 2 on the sealing resin layer 3 and the peeling force P2 of the second release material 4 on the sealing resin layer 3. If there is a difference between the peeling force P1 of the first release material 2 and the peeling force P2 of the second release material 4, the release material on the light release side can be easily peeled off, and the sealing resin layer 3 may be destroyed. Absent.
In addition, in this specification, the peeling force of a peeling material is the value measured based on JIS-Z0237: 2009.

In this embodiment, the ratio (P2 / P1) of the peeling force P2 of the second peeling material 4 to the peeling force P1 of the first peeling material 2 is 0.02 ≦ P2 / P1 <1 or 1 <P2 / P1 ≦ 50. It is preferable that
When the ratio (P2 / P1) of the peeling force P2 of the second peeling material 4 to the peeling force P1 of the first peeling material 2 is in the above range, the peeling property of the peeling material at the time of use becomes better.

From the viewpoint of preventing repellency of the sealing resin composition, the peeling force of the release material on the side to which the sealing resin composition for forming the sealing resin layer 3 described later is applied is preferably 10 mN / 100 mm or more. .
In this embodiment, since the sealing resin composition for forming the sealing resin layer 3 on the first release material 2 is applied, the peel force P1 of the first release material 2 is 10 mN / 100 mm or more. Is preferred. When the peeling force P1 of the first release material 2 is 10 mN / 100 mm or more, repellency of the sealing resin composition can be prevented, and sheet formability is improved. The upper limit value of the peeling force P1 of the first release material 2 can be set as appropriate. From the viewpoint of peelability from the sealing resin composition, the peel force P1 of the first release material 2 is preferably 500 mN / 100 mm or less. Moreover, the peeling force P2 of the 2nd peeling material 4 can also be set suitably. The peeling force P2 of the second release material 4 is preferably 10 mN / 100 mm or more and 500 mN / 100 mm or less. When the peeling force P2 of the second release material 4 is in the above range, it is possible to prevent the second release material 4 from being peeled off during handling of the semiconductor sealing adhesive sheet 1, and in use, the second release material 4 4 can be peeled well.

The first release material 2 and the second release material 4 have releasability, and the material is not particularly limited as long as there is a difference between the release force of the first release material 2 and the release force of the second release material. In addition to a member having peelability itself, a member subjected to a peeling treatment, a member on which a release agent layer is laminated, or the like may be used. Specifically, for example, olefin-based resins, ester-based resins, and release-treated polyethylene terephthalate (PET) can be used.
The first release material 2 and the second release material 4 can be a release material including a release substrate and a release agent layer formed by applying a release agent on the release substrate. By using a release material including a release substrate and a release agent layer, handling becomes easy. Moreover, the 1st release material 2 and the 2nd release material 4 may be equipped with the releasing agent layer only on the single side | surface of the peeling base material, and may be equipped with the peeling agent layer on both surfaces of the peeling base material.
Examples of the release substrate include a paper substrate, a laminated paper obtained by laminating a thermoplastic resin such as polyethylene on the paper substrate, and a plastic film. Examples of the paper substrate include glassine paper, coated paper, and cast coated paper. Examples of the plastic film include polyester films (for example, polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate), polyolefin films (for example, polypropylene, polyethylene, and the like), and the like.
Examples of release agents include silicone release agents composed of silicone resins; long-chain alkyl group-containing compound release agents composed of compounds containing long-chain alkyl groups such as polyvinyl carbamate and alkylurea derivatives; alkyd resins Alkyd resin-based release agent composed of (for example, non-convertible alkyd resin, convertible alkyd resin, etc.); olefin resin (for example, polyethylene (for example, high-density polyethylene, low-density polyethylene, and linear low-density polyethylene) Etc.), olefin resin release agents composed of propylene homopolymers having isotactic or syndiotactic structures, and crystalline polypropylene resins such as propylene-α-olefin copolymers; natural rubber, and Synthetic rubber (eg, butadiene rubber, Rubber release agent composed of rubber such as rubber, styrene-butadiene rubber, methyl methacrylate-butadiene rubber, and acrylonitrile-butadiene rubber; and acrylic resin such as (meth) acrylate copolymer In addition, various release agents such as acrylic resin release agents can be used, and these can be used alone or in combination of two or more.

The thickness of the first release material 2 and the second release material 4 is not particularly limited. Usually, it is 1 μm or more and 500 μm or less, and preferably 3 μm or more and 100 μm or less.
The thickness of the release agent layer is not particularly limited. When a release agent layer is formed by applying a solution containing a release agent, the thickness of the release agent layer is preferably 0.01 μm or more and 3 μm or less, and more preferably 0.03 μm or more and 1 μm or less.

(Sealing resin layer)
In this embodiment, the sealing resin composition that forms the sealing resin layer 3 is a thermosetting resin composition. As such a sealing resin composition, the sealing resin composition containing a binder component (A) and a thermosetting component (B) is mentioned, for example.

<Binder component (A)>
As the binder component (A), a known polymer can be used without particular limitation as the binder component of the sealing resin composition. For example, silicone resins (eg, alkyl-modified silicone resins, epoxy-modified silicone resins, alkyd-modified silicone resins, acrylic-modified silicone resins, polyester-modified silicone resins, phenyl silicone resins, and dimethyl silicone resins), epoxy resins, phenoxy resins, acrylics Examples thereof include resins, methacrylic resins, and urethane resins.

From the viewpoint of imparting appropriate tackiness at the use temperature (mainly normal temperature), an acrylic polymer is preferably used as the binder component (A). Examples of the repeating unit of the acrylic polymer include a repeating unit derived from a (meth) acrylic acid ester monomer and a (meth) acrylic acid derivative. Here, as the (meth) acrylic acid ester monomer, for example, (meth) acrylic acid cycloalkyl ester, (meth) acrylic acid benzyl ester, and (meth) acrylic acid alkyl ester whose alkyl group has 1 to 18 carbon atoms Etc. are used. Among these, (meth) acrylic acid alkyl esters having an alkyl group with 1 to 18 carbon atoms (for example, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate) Butyl acrylate, butyl methacrylate, and the like). Examples of the (meth) acrylic acid derivative include glycidyl (meth) acrylate.
In this specification, the normal temperature is a temperature of 18 ° C. or higher and 30 ° C. or lower.

  As the binder component (A), a copolymer containing a (meth) acrylic acid glycidyl unit and at least one (meth) acrylic acid alkyl ester unit is more preferable. In this case, the content of the component unit derived from glycidyl (meth) acrylate in the copolymer is usually more than 0% by mass and 80% by mass or less, preferably 5% by mass or more and 50% by mass or less. . By introducing a glycidyl group, compatibility with an epoxy resin as a thermosetting component (B) described later is improved, and Tg after curing is increased, thereby improving heat resistance. Moreover, as (meth) acrylic-acid alkylester, it is preferable to use methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, etc., for example. Further, by introducing a hydroxyl group-containing monomer such as hydroxyethyl acrylate, it becomes easy to control the adhesion to the adherend and the physical properties of the adhesive.

  From the viewpoint of imparting appropriate tackiness at the use temperature (mainly normal temperature), the weight average molecular weight of the acrylic polymer is preferably 100,000 or more, more preferably 150,000 or more and 1,000,000 or less.

<Thermosetting component (B)>
The thermosetting component (B) has a property of forming a three-dimensional network when heated and bonding the adherend firmly.
Various thermosetting components are known, and the thermosetting component (B) in the present embodiment is not particularly limited, and various conventionally known thermosetting components can be used. Generally, it is formed from a thermosetting resin (for example, epoxy, phenol, resorcinol, urea, melamine, furan, unsaturated polyester, silicone, etc.) and an appropriate curing accelerator, for example, (B Examples thereof include a thermosetting component composed of -1) an epoxy resin and (B-2) a thermally activated latent epoxy resin curing agent.

Various conventionally known epoxy resins are used as the epoxy resin (B-1).
From the viewpoint of moderate adhesiveness after thermosetting, an epoxy resin having a weight average molecular weight of 300 to 2,000 is preferred, and an epoxy resin having a weight average molecular weight of 300 to 500 is more preferred. An epoxy resin obtained by blending a normal liquid epoxy resin having a weight average molecular weight of 330 to 400 and a normal solid epoxy resin having a weight average molecular weight of 400 to 2000 (preferably 500 to 1500) is more preferable.
The epoxy equivalent of the epoxy resin preferably used in this embodiment is usually 50 to 5000 g / eq. Specific examples of such epoxy resins include glycidyl ethers of phenols (eg, bisphenol A, bisphenol F, resorcinol, phenyl novolac, and cresol novolac), alcohols (eg, butanediol, polyethylene glycol). And glycidyl ethers of carboxylic acids (eg, phthalic acid, isophthalic acid, tetrahydrophthalic acid, etc.), epoxy resins of glycidyl type or alkyl glycidyl type (eg, aniline isocyanurate, etc.) Epoxy resin substituted with glycidyl group for the active hydrogen bonded), and so-called alicyclic epoxide (eg, by oxidizing the carbon-carbon double bond in the molecule, Charged resin (eg, vinylcyclohexane diepoxide, 3,4-epoxycyclohexylmethyl-3,4-dicyclohexanecarboxylate, eg, 2- (3,4-epoxy) cyclohexyl-5,5-spiro (3 4-epoxy) cyclohexane-m-dioxane and the like)) and the like. Alternatively, a dicyclopentadiene skeleton-containing epoxy resin having a dicyclopentadiene skeleton and a reactive epoxy group in the molecule may be used.
These epoxy resins can be used alone or in combination of two or more.

  The thermally activated latent epoxy resin curing agent (B-2) is a type of curing agent that does not react with the epoxy resin at room temperature but is activated by heating at a certain temperature or more and reacts with the epoxy resin.

  As a method for activating the thermally activated latent epoxy resin curing agent (B-2), “method of generating active species (anion, cation) by chemical reaction by heating”, “compatibility and dissolution with epoxy resin at high temperature” And a method of initiating a curing reaction ”(at around room temperature, the thermally activated latent epoxy resin curing agent (B-2) is stably dispersed in the epoxy resin (B-1)),“ a molecular sieve encapsulated type and And a method of starting the curing reaction by eluting the cured curing agent at a high temperature, a “method using microcapsules”, and the like.

  These thermally activated latent epoxy resin curing agents (B-2) can be used singly or in combination of two or more. Among the above, dicyandiamide, an imidazole compound or a mixture thereof is more preferable.

  The thermally activated latent epoxy resin curing agent (B-2) as described above is usually 0.1 to 20 parts by mass, preferably 0.5 to 100 parts by mass of the epoxy resin (B-1). It is used in a proportion of not less than 15 parts by mass and more preferably not less than 1 part by mass and not more than 10 parts by mass.

<Other components (C)>
In this embodiment, the sealing resin composition forming the sealing resin layer 3 may contain other components (C) in addition to the binder component (A) and the thermosetting component (B). . Examples of the other component (C) include a coupling agent (C1). The coupling agent (C1) desirably has a group that reacts with the functional group of the binder component (A) or the thermosetting component (B), preferably the thermosetting component (B).

  The coupling agent (C1) is considered to react with the thermosetting component (B) (preferably epoxy resin) during the curing reaction, and the organic functional group in the coupling agent is bonded without impairing the heat resistance of the cured product. Property and adhesion can be improved, and water resistance (moisture heat resistance) is also improved.

  The coupling agent (C1) is preferably a silane (silane coupling agent) because of its versatility and cost merit. The coupling agent (C1) as described above is usually 0.1 parts by mass or more and 20 parts by mass or less, preferably 0.3 parts by mass or more and 15 parts by mass with respect to 100 parts by mass of the thermosetting component (B). Or less, more preferably 0.5 parts by mass or more and 10 parts by mass or less.

  In addition, the encapsulating resin composition for forming the encapsulating resin layer 3 includes a crosslinking agent (C2) (for example, an organic polyvalent isocyanate compound, and an organic compound in order to adjust initial adhesion and aggregation before curing. A polyvalent imine compound or the like) can also be added.

  Examples of the organic polyvalent isocyanate compound include aromatic polyvalent isocyanate compounds, aliphatic polyvalent isocyanate compounds, alicyclic polyvalent isocyanate compounds, and trimers of these polyvalent isocyanate compounds, Also included are terminal isocyanate urethane prepolymers obtained by reacting these polyvalent isocyanate compounds with polyol compounds. More specific examples of the organic polyvalent isocyanate compound include, for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, and 1,4-xylene diene. Isocyanate, diphenylmethane-4,4′-diisocyanate, diphenylmethane-2,4′-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4 Examples include '-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, and lysine isocyanate.

  Specific examples of the organic polyvalent imine compound include, for example, N, N′-diphenylmethane-4,4′-bis (1-aziridinecarboxamide), trimethylolpropane-tri-β-aziridinylpropionate, Examples include tetramethylolmethane-tri-β-aziridinylpropionate, N, N′-toluene-2,4-bis (1-aziridinecarboxamide) triethylenemelamine, and the like. The crosslinking agent (C2) as described above is usually blended at a ratio of 0.1 to 20 parts by mass, preferably 0.2 to 10 parts by mass with respect to 100 parts by mass of the binder component (A). Is done.

  Further, for example, asbestos, silica, glass, mica, chromium oxide, titanium oxide, and a filler (C3) such as a pigment may be added to the sealing resin composition forming the sealing resin layer 3. . When these fillers (C3) are blended in the sealing resin composition, the total amount of the components (excluding the filler) constituting the sealing resin layer 3 exceeds 100 parts by weight and exceeds 400 parts by weight. You may mix | blend in the ratio below a grade.

  Moreover, in order to control the thermal responsiveness (melt property) of the sealing resin layer 3, the sealing resin composition forming the sealing resin layer 3 includes a thermoplastic resin having a glass transition point at 60 to 150 ° C. C4) may be blended. Examples of the thermoplastic resin (C4) include polyester resin, polyvinyl alcohol resin, polyvinyl butyral, polyvinyl chloride, polystyrene, polyamide resin, cellulose, polyethylene, polyisobutylene, polyvinyl ether, polyimide resin, polymethyl methacrylate, styrene-isoprene. -A styrene block copolymer, a styrene-butadiene-styrene block copolymer, etc. are mentioned.

  The blending ratio of the thermoplastic resin in the sealing resin layer 3 is preferably 1 part by mass or more and 50 parts by mass or less, more preferably 2 parts by mass, per 100 parts by mass in total of the binder component (A) and the thermosetting component (B). Part to 40 parts by weight, more preferably 3 parts to 30 parts by weight. When an acrylic polymer is used as the binder component (A), the weight ratio of the acrylic polymer to the thermoplastic resin (acrylic polymer / thermoplastic resin) is 9/1 to 3/7. Preferably it is.

(Manufacturing method of semiconductor sealing adhesive sheet)
The manufacturing method of the adhesive sheet 1 for semiconductor sealing is not specifically limited.
For example, the semiconductor sealing adhesive sheet 1 is manufactured through the following steps.
First, the sealing resin composition is applied onto the first release material 2 to form a coating film. Next, this coating film is dried to form the sealing resin layer 3.
Next, the adhesive sheet 1 for semiconductor sealing is obtained by bonding the sealing resin layer 3 and the second release material 4 at room temperature.

  Since the adhesive sheet 1 for semiconductor sealing according to the present embodiment has a difference between the peeling force P1 of the first release material 2 and the release force P2 of the second release material 4, the release material of the adhesive sheet for semiconductor sealing is used. When peeling and using, the release material on the light release side can be easily peeled without destroying the sealing resin layer 3.

  The semiconductor element can be sealed using the semiconductor sealing adhesive sheet of the present embodiment, for example, as follows. After peeling the release material on the light release side of the semiconductor adhesive sheet, a sealing resin layer is placed so as to cover the semiconductor element. Thereafter, the release material on the heavy release side is peeled off. Thereafter, the semiconductor element is sealed by pressure bonding by a vacuum laminating method.

[Modification of Embodiment]
The present invention is not limited to the above-described embodiment, and modifications and improvements as long as the object of the present invention can be achieved are included in the present invention.

  For example, although the embodiment described the semiconductor sealing application, the adhesive sheet of the present invention can be used for other insulating materials for circuit boards (for example, hard printed wiring board materials, flexible wiring board materials, and build-up boards). Interlayer insulating material, etc.), an adhesive film for build-up, and an adhesive.

  Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited to these examples.

[Measurement of peel force]
After mixing the materials shown in Table 1, they were uniformly dissolved and dispersed with a high-speed rotary mixer to prepare a resin varnish.
Next, a die coater is used so that the thickness of the encapsulating resin composition after drying is 50 μm on each of the release materials of types (1) to (4) (polyethylene terephthalate whose surface is peel-treated, thickness 38 μm). The resin varnish was applied by and dried at 100 ° C. for 7 minutes to form a sealing resin layer on the release material.
Next, the peel force between the release material and the sealing resin layer was measured according to JIS-Z0237: 2009 (measurement conditions: 300 mm / min, 100 mm width under 23 ° C./50% RH). ). The measurement results are shown in Table 2.
In addition, in each peeling material (type (1)-(4)), each peeling force was controlled by the said peeling process.

BA: butyl acrylate,
MA: methyl acrylate
GMA: glycidyl methacrylate,
HEA: 2-hydroxyethyl acrylate.

[Examples 1 to 4 and Comparative Example 1]
On the first release material (polyethylene terephthalate whose surface is release-treated, thickness 38 μm), a resin varnish is applied with a die coater so that the thickness of the sealing resin composition after drying is 50 μm, and at 100 ° C. Dry for 7 minutes. Immediately after being taken out from the drying furnace, the sealing resin composition after drying and the second release material (polyethylene terephthalate whose surface is release-treated, thickness 38 μm) are bonded together at room temperature, and the first release material, sealing The adhesive sheet for semiconductor sealing by which the stop resin layer and the 2nd peeling material were laminated | stacked in this order was produced.
The types of release materials (first release material and second release material) used in Examples 1 to 4 and Comparative Example 1 are as shown in Table 3.

〔Evaluation method〕
Evaluation of the adhesive sheet for semiconductor encapsulation was performed according to the following method.

[Peelability evaluation]
In Examples 1 to 4 and Comparative Example 1, after peeling off one release material, an adhesive sheet (sheet obtained by laminating an adhesive layer on a PET film) was separately attached to the sealing resin layer, and the other release material was attached. By peeling, the peelability of the semiconductor sealing adhesive sheet was evaluated.
If the first release material and the second release material can be peeled off without cracking the sealing resin layer, it is evaluated as “A”, and when the first release material or the second release material is peeled, the sealing resin layer is cracked. When a problem such as the above occurred, it was evaluated as “B”. The results are shown in Table 3.

  As shown in Table 3, about Examples 1-4, it turned out that favorable peelability is obtained by providing a difference in the peeling force of a 1st peeling material and the peeling force of a 2nd peeling material.

[Sheet formability evaluation]
The sheet formability was evaluated for the release material whose release force was controlled to 1000 mN / 100 mm, 500 mN / 100 mm, 100 mN / 100 mm, 50 mN / 100 mm, 25 mN / 100 mm, and 1 mN / 100 mm. The resin varnish used in Examples 1 to 4 and Comparative Example 1 was applied to each release material and dried at 100 ° C. for 7 minutes. The sealing resin layer immediately after drying is visually observed. If there is no part where the sealing resin layer is repelled and the release material is exposed, it is evaluated as “C”, and if there is an exposed part, “D ". The results are shown in Table 4.

  DESCRIPTION OF SYMBOLS 1 ... Adhesive sheet for semiconductor sealing, 2 ... 1st peeling material, 3 ... Sealing resin layer, 4 ... 2nd peeling material.

Claims (3)

An adhesive sheet,
The first release material, the resin layer, and the second release material are laminated in this order,
The resin layer includes a thermosetting resin composition,
An adhesive sheet having a difference between a peeling force P1 of the first release material to the resin layer and a peeling force P2 of the second release material to the resin layer.   The ratio (P2 / P1) of the peel force P2 of the second release material to the peel force P1 of the first release material is 0.02 ≦ P2 / P1 <1 or 1 <P2 / P1 ≦ 50. The adhesive sheet according to 1. The adhesive sheet according to claim 1 or 2, which is for semiconductor encapsulation.

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