JP2002161251A - Adhesive film, method for producing the same, and method for adhering the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive film capable of minimizing entrapment of air bubbles, when the film is subjected to pressing after roll-laminated, to pro vide a method for producing the same and to provide a method for adhering the adhesive film to an adherend. SOLUTION: This adhesive film is formed by applying an adhesive to a film base material, wherein at least one of both the surfaces of the film base material is matte-finished. The film base material preferably has a surface tension of <=35 dyne/cm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive film used for bonding semiconductor parts / materials and electronic parts / materials, a method for producing the adhesive film, and a method for bonding with the adhesive film.

[0002]

2. Description of the Related Art As a method of bonding an electronic component, a heat sink, or a stiffener to a wiring board, there is a method of using an adhesive film. At that time, there is a method in which an adhesive film is first adhered to one adherend using a roll laminator, and then the adhesive film is adhered to the other adherend using a press or an autoclave.

[0003]

At this time, the step of bonding using a press machine is more difficult than a roll laminator.
Since it is difficult to cope with irregularities on the substrate surface, there is a problem that air bubbles are easily mixed in, and the air bubbles once mixed are difficult to remove. As a result, when the adhesive is heated in the curing of the adhesive or in the solder reflow process, there is a problem that bubbles in the poor adhesion portion are enlarged and cause a failure.

On the other hand, in the method of forming an emboss on the surface of the adhesive (JP-A-6-216524 and JP-A-10-92971), a new coating roll is required to form the emboss. there were. In this case, since the emboss is formed on the side opposite to the surface of the base material, it is difficult to bond the emboss surface during the press in which air bubbles are likely to be generated in the above-described steps.

[0005] In view of the above problems, the present invention relates to an adhesive film capable of minimizing the entrapment of air bubbles in a pressing step after roll lamination, a method of manufacturing the same, and a method of bonding the adhesive film.

[0006]

The present invention relates to the following. (1) An adhesive film, wherein an adhesive is applied on a film substrate having a matte-treated surface on at least one side. (2) An adhesive film in which the surface tension of a film substrate having a matte-treated surface on at least one side is 35 dyn / cm or less. (3) An adhesive film in which the main component of the adhesive is a thermosetting resin. (4) An adhesive film in which the main component of the thermosetting resin contains an epoxy resin or an acrylic rubber. (5) at least one surface has a matted surface,
A method for producing an adhesive film, comprising applying an adhesive composition mainly composed of a thermosetting resin onto a film substrate having a surface tension of 35 dyn / cm or less. (6) at least one surface has a matted surface,
And, on a film substrate having a surface tension of 35 dyn / cm or less, on one surface of an adhesive film obtained by applying an adhesive composition mainly composed of a thermosetting resin, and on one adherend. A bonding method in which a film substrate of an adhesive film is peeled off and removed from an adhesive interface, and the other adherend is attached to the exposed adhesive surface.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The film substrate used in the present invention includes polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate, polyolefins such as polyethylene, polypropylene, polystyrene and EVA, polyvinyl chloride, and polyvinyl chloride. The base material may be a vinyl resin such as vinylidene, or a plastic such as polysulfone, polyethersulfone, polycarbonate, polyamide, polyimide, acrylic resin, or polyacetylcellulose. Among these films, a polyethylene terephthalate film or a polycarbonate film is preferred in terms of transparency, heat resistance, ease of handling, and price.

[0008] The film substrate has a total visible light transmittance of 70%.
Those having a thickness of 1 mm or less are preferable. The film substrate may be used in a single layer, but may be formed into a multilayer body by combining two or more layers.

At this time, the thickness of the film substrate is 5 to 50.
0 μm is preferred. If it is less than 5 μm, the handleability tends to deteriorate, and if it exceeds 500 μm, the transmittance of visible light tends to decrease. The thickness of the film substrate is
More preferably, the thickness is 10 to 200 μm.

[0010] These film substrates are matted. As an index that quantitatively represents the degree of mat processing,
It is appropriate to express the turbidity or surface roughness of the film. That is, the degree of matting required in the present invention is 10% or more in terms of turbidity of the film, or the surface roughness of the film is 1.0 μm in Ra value and 2.5 μm in Rz value.
It is necessary to satisfy at least one of m or more.

On the other hand, since the matted surface of the film substrate is peeled off after the application of the adhesive, its surface tension needs to be 35 dyn / cm or less. If this value is larger than 35 dyn / cm, it is difficult to remove the adhesive after applying the adhesive. There is no particular limitation on the value of the surface tension of the back surface of the film substrate that has not been subjected to the matting treatment, but it is preferable that the release treatment or the like is performed because the occurrence of blocking and the like of the film substrate is suppressed. is there.

The adhesive used in the adhesive layer of the present invention includes:
A thermosetting resin is preferable, and among them, a thermosetting system composed of an epoxy resin and an acrylic rubber is more preferable.
Examples of epoxy resins include bisphenol A epoxy resin, bisphenol F epoxy resin, tetrahydroxyphenylmethane epoxy resin, novolak epoxy resin, resorcinol epoxy resin, polyalcohol.
Epoxy resins such as polyglycol type epoxy resin, polyolefin type epoxy resin, alicyclic and halogenated bisphenol can be used.

Examples of the acrylic rubber include polyethyl acrylate, polybutyl acrylate, poly-2-ethylhexyl acrylate, poly-t-butyl acrylate, poly-3-ethoxypropyl acrylate, polyoxycarbonyltetramethacrylate, polymethyl Acrylate, polyisopropyl acrylate, polydodecyl methacrylate, polytetradecyl methacrylate,
Poly-n-propyl methacrylate, poly-3, 3, 5
-Poly (meth) acrylates such as trimethylcyclohexyl methacrylate, polyethyl methacrylate, poly-2-nitro-2-methylpropyl methacrylate, polytetracarbanyl methacrylate, poly-1,1-diethylpropyl methacrylate, and polymethyl methacrylate Can be used. If necessary, these acrylic polymers may be copolymerized with two or more kinds,
Two or more types can be blended and used.

When the acrylic rubber and the epoxy resin are blended and used, the blending amount is 5 to 100 parts by weight of the epoxy resin, and 10 to 10 parts by weight of the acrylic rubber.
50 parts by weight are preferred. When the amount is less than 5 parts by weight, the adhesion is poor, and when the amount is more than 100 parts by weight, the adhesive strength at the time of absorbing moisture tends to decrease.

Furthermore, epoxy acrylate, urethane acrylate, polyether acrylate, polyester acrylate and the like can be used as the copolymer resin of acrylic resin and other than acrylic resin. Epoxy acrylates include 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, allyl alcohol diglycidyl ether, resorcinol diglycidyl ether, adipic acid diglycidyl ester, phthalic acid diglycidyl ester, polyethylene glycol diglycidyl (Meth) acrylic acid adducts such as ether, trimethylolpropane triglycidyl ether, glycerin triglycidyl ether, pentaerythritol tetraglycidyl ether, sorbitol tetraglycidyl ether and the like can be mentioned.

In addition to these resins, thermoplastic resins such as natural rubber, polyisoprene, poly-1,2-butadiene, polyisobutene, polybutene, poly-2-heptyl-1,3-butadiene, and poly-2-t -Butyl-1,
(Di) enes such as 3-butadiene and poly-1,3-butadiene, ethers such as polyoxyethylene, polyoxypropylene, polyvinyl ethyl ether, polyvinyl hexyl ether and polyvinyl butyl ether, polyvinyl acetate and polyvinyl propionate And polyesters, polyurethane, ethyl cellulose, polyvinyl chloride, polyacrylonitrile, polymethacrylonitrile, polysulfone, polysulfide, phenoxy resin, and the like.

Also, a polyimide resin or a polyamide resin can be used. Polyamide imide or polyamide epoxy can also be used as a copolymer resin of polyamide resin and other than amide.

When these thermoplastic resins other than acrylic rubber are used, the amount of the epoxy resin is 5 to 100 parts by weight, and also 10 to 100 parts by weight of the thermoplastic resin. 50 parts by weight are preferred. If the amount of the epoxy resin is less than 5 parts by weight, the adhesion is insufficient, and if it exceeds 100 parts by weight, the adhesive strength at the time of moisture absorption is reduced.

On the other hand, the thermosetting reactive group includes a resin having a functional group such as a carboxyl group, a hydroxyl group, an epoxy group, an amino group, and an unsaturated hydrocarbon group, and a resin having an epoxy group, a hydroxyl group, an amino group, an amide group, a carboxyl group. It is used in combination with a curing agent having a functional group such as a group or a mercapto group or a curing agent such as a metal chloride, an isocyanate compound, an acid anhydride, a metal oxide, or a peroxide. In order to increase the curing reaction rate, an additive such as a catalyst may be used.

The adhesive layer is preferably bonded at a temperature of 180 ° C. or lower from the viewpoint of good workability, and more preferably bonded at 170 ° C. or lower. In addition, from the viewpoint of workability and pressure resistance of the adherend, it is preferable that the adhesive be applied at 30 kgf / cm ² or less. The adhesive layer is preferably in the form of an adhesive sheet because it can be easily handled and the mixing of air bubbles can be reduced. The thickness of the adhesive layer is preferably 5 μm or more, and more preferably 20 μm or more from the viewpoint of the surface roughness of the wiring board, heat sink, and stiffener.

[0021]

Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

(Example 1) An adhesive film 1 produced according to the following adhesive film production example 1 was coated with a roll laminator at 100 ° C. and ² kgf / cm ² at a thickness of 3 mm.
It was bonded to an aluminum plate. Thereafter, the base film on the adhesive was peeled off and the wiring substrate (average surface roughness: 20 μm) was overlaid on the exposed adhesive surface, and the pressure was set to 3 kgf / g in a 150 ° C. autoclave using nitrogen gas. c
m ² and heated and pressed to obtain a structure 1 including a wiring substrate, an aluminum radiator plate, and an adhesive layer.

<Adhesive Film Preparation Example 1> A matte-treated film (manufactured by Teijin Limited, trade name U-
71; thickness 50 μm, film turbidity 15, matte surface tension 28 dyn / cm), dry coating thickness 80 μm
m. The adhesive film thus obtained was used as an adhesive film 1.

<Adhesive Composition 1> Epicoat YL-983U (trade name of Yuka Shell Epoxy Co., Ltd., bisphenol F type epoxy resin) 40 parts by weight HTR-708-6T (trade name of Teikoku Chemical Industry Co., Ltd.) Name, high molecular weight acrylic resin) 60 parts by weight Epicoat 1001 (trade name of Yuka Shell Epoxy Co., Ltd., bisphenol A type epoxy resin) 10 parts by weight Sumidur N (Sumitomo Bayer Urethane Co., Ltd.), aliphatic trifunctional Isocyanate) 5 parts by weight 2-Ethyl-4-methylimidazole 0.5 parts by weight Alumina (average particle size: 5 μm) 80 parts by weight Methyl ethyl ketone (hereinafter referred to as MEK) 15 parts by weight

(Example 2) The adhesive film 2 produced in the following adhesive film production example 2 was bonded to a stainless steel plate having a thickness of 5 mm at 90 ° C and 5 kgf / cm ² using a roll laminator. Thereafter, the base film on the adhesive was peeled off, and a wiring board (average surface roughness: 35 μm) was placed on the exposed adhesive surface, and the pressure was set to 10 kgf in a 170 ° C. autoclave using nitrogen gas.
/ Cm ² and heated and pressed to obtain a structure 2 including a wiring board, a stainless steel radiator plate, and an adhesive layer.

<Adhesive Film Production Example 2> A matte-treated film (trade name: M-
71; thickness 38 μm, film turbidity 40, matte surface tension 26 dyn / cm) and dry coating thickness 100
It was applied to a thickness of μm. The adhesive film thus obtained was used as an adhesive film 2.

<Adhesive composition 2> TBA-HME (trade name, manufactured by Hitachi Chemical Co., Ltd., high molecular weight epoxy resin) 100 parts by weight YD-8125 (trade name, Toto Kasei Co., Ltd., bisphenol A epoxy resin) 25 parts by weight IPDI (trade name, mask isocyanate manufactured by Hitachi Chemical Co., Ltd.) 10 parts by weight 2-ethyl-4-methylimidazole 0.5 part by weight Alumina (particle size: 5 μm) 90 parts by weight MEK 30 parts by weight

Example 3 An adhesive film 3 produced in the following adhesive film production example 3 was used at a temperature of 100 ° C. and 3 kgf / cm ² at a thickness of 7.5 using a roll laminator.
mm nickel plate. Thereafter, the base film on the adhesive was peeled off, and a wiring board (average surface roughness: 25 μm) was superposed on the exposed adhesive surface, and the pressure was increased to 15 k in an autoclave at 160 ° C. using nitrogen gas.
gf / cm ² , and heat and pressure bonded to form a structure 3 comprising a wiring board, a nickel radiator plate, and an adhesive layer
I got

<Adhesive Film Preparation Example 3> The following adhesive composition 3 was used as a matted film (manufactured by Teijin Limited, trade name U-
71; thickness 50 μm, film turbidity 15, matte surface tension 28 dyn / cm), and dry coating thickness 75 μm
m. The adhesive film thus obtained was used as an adhesive film 3.

<Adhesive Composition 3> Epicoat 828 (trade name, manufactured by Yuka Shell Epoxy Co., Ltd., bisphenol A type epoxy resin) 80 parts by weight HTR-708-6T (trade name, manufactured by Teikoku Chemical Industry Co., Ltd.) High molecular weight acrylic resin) 5 parts by weight ESCN190-3 (trade name, manufactured by Sumitomo Chemical Co., Ltd., cresol novolak type epoxy resin) 20 parts by weight Sumidur N (Sumitomo Bayer Urethane Co., Ltd., aliphatic trifunctional isocyanate) G) 5 parts by weight 2-ethyl-4-methylimidazole 0.5 parts by weight Alumina (particle size: 5 μm) 80 parts by weight

Example 4 The autoclave pressure was 20
A structure 4 was obtained in the same manner as in Example 1, except that the composition was kgf / cm ² .

Example 5 A structure 5 was obtained in the same manner as in Example 1 except that the thickness of the adhesive was 50 μm.

(Comparative Example 1) Instead of mat-treated PET, ordinary surface-treated PET (trade name A, manufactured by Toyobo Co., Ltd.)
Except for using -4100, a thickness of 50 µm, a film turbidity of 3.0, and a surface tension of 30 dyn / cm), a construction 6 was obtained in the same manner as in Example 1.

Comparative Example 2 A structure 7 was obtained in the same manner as in Example 2 except that a mat-treated PET having a surface tension of 40 dyn / cm was used.

Comparative Example 3 In the manufacture of the structure 3 in Example 3, a structure 8 was obtained in the same manner as in Example 3 except for the following procedure. That is, after preparing the adhesive film, the matte-treated PET film side of the adhesive film was bonded to a nickel plate using a roll laminator, and then a wiring substrate was bonded to the opposite surface side, thereby forming a structure 8.

The surface roughness of the wiring board was measured by using a surface roughness measuring device (SV-400, manufactured by Mitutoyo Corporation) at intervals of 5 mm in the vertical and horizontal directions of the wiring board surface (measurement width: 50 mm), and the maximum value was taken as the value of the surface roughness of the substrate. The properties of the structures obtained in Examples 1 to 5 and Comparative Examples 1 to 3 were measured by the following methods. The adhesive force was prepared as a sample for measuring adhesive force using a copper foil instead of a heat sink, and using a tensile tester (manufactured by Toyo Baldwin Co., Ltd., Tensilon UTM-4-100). The measurement was performed at a width of 10 mm, a direction of 90 ° and 50 mm / min. The presence or absence of air bubbles was observed from the side of the heat sink using an ultrasonic imager (AT5500, manufactured by Hitachi Construction Machinery Co., Ltd.). Solder reflow is performed using a solder bath (temperature 2
The composition was charged at 60 ° C.), and after 1 minute, the sample without floating and peeling was rated OK, and the sample with floating and peeling was rated NG. Table 1 shows the configurations and characteristics of the structures obtained in Examples 1 to 5 and Comparative Examples 1 to 3.

[Table 1]

[0037]

According to the adhesive film and the adhesive method of the present invention, air bubbles mixed between the wiring board and the heat radiating plate can be reduced, and the poor adhesion can be eliminated. A substrate and a heat sink can be manufactured.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Mari Tabe 1150 Goshomiya, Odate, Shimodate City, Ibaraki Prefecture F-term in Goshomiya Office, Hitachi Chemical Co., Ltd. 4J004 AA02 AA10 AA13 AB05 CA02 CA03 CA04 CA06 CC02 CD07 FA05 FA08

Claims (6)

[Claims] 1. An adhesive film characterized in that an adhesive is applied on a film substrate on which at least one surface is matted. 2. The adhesive film according to claim 1, wherein the surface tension of the film substrate on which at least one surface is matted is 35 dyn / cm or less. 3. The adhesive film according to claim 1, wherein a main component of the adhesive is a thermosetting resin. 4. The thermosetting resin according to claim 1, wherein a main component of the thermosetting resin includes an epoxy resin or an acrylic rubber.
The adhesive film according to any one of the above. 5. An adhesive composition containing a thermosetting resin as a main component is applied to a film substrate having at least one surface subjected to a mat treatment and having a surface tension of 35 dyn / cm or less. Method for producing an adhesive film. 6. An adhesive composition containing a thermosetting resin as a main component is coated on a film substrate having at least one surface matted and having a surface tension of 35 dyn / cm or less. When bonding two adherends using an adhesive film, one adherend is attached using a laminator to the surface of the adhesive opposite to the base film of the adhesive film, and then, A bonding method, wherein the other adherend is attached to the exposed adhesive surface by peeling and removing a film substrate of the adhesive film from an adhesive interface using a press or an autoclave.