JP2019134095A - Film-coated electronic component mounting substrate for sealing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To seal an unevenness provided on an electronic component mounting substrate with excellent followability by a resin layer and a sealing film, and to suppress permeation of water vapor to the electronic component provided on the electronic component mounting substrate. To provide a substrate for mounting a film-coated electronic component for encapsulation. SOLUTION: The encapsulating film-coated electronic component mounting substrate 50 of the present invention covers at least a part of an electronic component mounting substrate 45 including the substrate 5 and the electronic component 4, and the substrate 5 and the electronic component 4. The resin layer 7 has a sealing film 100 that covers at least a part of the substrate 5 and the electronic component 4 via the resin layer 7, and the resin layer 7 is composed of a solvent-soluble resin as a main material. The sealing film 100 is composed of a resin material as a main material, and has an elongation rate of 150% or more and 3500% or less at a softening point required in accordance with JIS K 6251. [Selection diagram] Fig. 1

Description

  The present invention relates to a film-coated electronic component mounting substrate for sealing.

  Conventionally, in electronic devices such as mobile phones, smartphones, calculators, electronic newspapers, tablet terminals, videophones, personal computers, for example, electronic component mounting substrates on which electronic components such as semiconductor elements, capacitors, and coils are mounted. Although mounted, the electronic component mounting board may be sealed with resin for the purpose of preventing contact with external factors such as moisture and dust.

  For such sealing with resin, for example, a potting method is known in which an electronic component mounting substrate is placed in a metal cavity and then sealed by injecting a thermosetting resin such as a highly fluid urethane resin. Yes.

  However, the potting method has a problem in that it takes time to cure the thermosetting resin, and further, usually requires a metal cavity for sealing, resulting in an increase in the weight of the resulting electronic device.

  In order to solve such problems, it has been proposed to apply a barrier film having hot melt properties to an electronic component mounting substrate (see, for example, Patent Document 1).

  However, in this case, the followability to the unevenness formed due to the electronic component mounting substrate including the electronic component is not sufficiently obtained, and as a result, the barrier property against external factors such as moisture and dust is sufficiently improved. It has not reached. In particular, in the electronic component mounting substrate provided in electronic equipment placed outdoors such as water meters, outdoor units provided in air conditioners and solar power generation systems, moisture (water vapor) permeability is suppressed depending on the usage environment. Is required.

JP 2009-99417 A

  An object of the present invention is to seal water vapor to an electronic component provided in the electronic component mounting substrate that is sealed with excellent followability by the resin layer and the sealing film against the unevenness provided in the electronic component mounting substrate. An object of the present invention is to provide a film-covered electronic component mounting substrate for sealing in which the above is suppressed.

Such an object is achieved by the present invention described in the following (1) to (7).
(1) An electronic component mounting substrate comprising a substrate and an electronic component mounted on the substrate;
A resin layer covering at least a part of the substrate and the electronic component;
A sealing film that covers at least a part of the substrate and the electronic component via the resin layer;
The resin layer is composed mainly of a solvent-soluble resin,
The sealing film is composed of a resin material as a main material, and has an elongation at a softening point required in accordance with JIS K 6251 of 150% or more and 3500% or less. Component mounting board.

  (2) The sealing film-covered electronic component mounting substrate according to (1), wherein the sealing film has a linear expansion coefficient of 100 ppm / ° C. or less in a temperature range of 25 ° C. or more and 80 ° C. or less.

  (3) The sealing film-covered electronic component mounting substrate according to (1) or (2), wherein the sealing film has one or more layers mainly composed of a thermoplastic resin.

  (4) The sealing film-covered electronic component mounting substrate according to any one of (1) to (3), wherein the sealing film has an average thickness of 10 μm or more and 200 μm or less.

(5) The sealing film-covered electronic component mounting substrate according to any one of (1) to (4), wherein the sealing film has a storage elastic modulus at 80 ° C. of 1 × 10 ⁵ Pa or more.

  (6) The film-coated electronic component for sealing according to any one of (1) to (5), wherein the solvent-soluble resin is at least one of (meth) acrylic resin, polyolefin elastomer, and urethane resin. Mounting board.

  (7) The film-covered electronic component mounting substrate for sealing according to any one of (1) to (6), wherein the substrate is a printed wiring board.

  According to the present invention, in the sealing film-covered electronic component mounting substrate, the resin layer that covers at least a part of the substrate and the electronic component is composed mainly of a solvent-soluble resin. Thereby, in the film-covered electronic component mounting substrate for sealing, the resin layer is coated in a state of following with excellent followability with respect to the unevenness formed by mounting the electronic component on the substrate. Yes.

  Furthermore, the sealing film covers at least a part of the substrate and the electronic component via the resin layer described above, and is composed of a resin material as a main material, and is required to be compliant with JIS K 6251 The elongation at the point is 150% or more and 3500% or less. Therefore, in the sealing film-covered electronic component mounting substrate, the sealing film is coated with excellent followability with respect to the unevenness covered with the resin layer.

  Therefore, the sealing film-covered electronic component mounting substrate can be sealed with excellent followability by the resin layer and the sealing film with respect to the unevenness of the electronic component mounting substrate.

  Further, in the sealing film-coated electronic component mounting substrate of the present invention, the resin layer composed mainly of a solvent-soluble resin covers at least a part of the substrate and the electronic component. (Water vapor) permeability is accurately suppressed. Therefore, the sealing film-covered electronic component mounting substrate of the present invention is applied to, for example, a water meter, an outdoor unit provided in an air conditioner and an electronic device provided outdoors such as a solar power generation system. However, since it is possible to accurately suppress the water vapor from reaching the electronic component included in the film-covered electronic component mounting substrate for sealing, the occurrence of the failure of the electronic component due to the contact of the water vapor is accurately suppressed. . As a result, an electronic apparatus provided with the sealing film-coated electronic component mounting substrate of the present invention has excellent reliability.

It is a longitudinal cross-sectional view which shows embodiment of the film coating electronic component mounting board | substrate for sealing of this invention. It is a longitudinal cross-sectional view which shows 1st Embodiment of the film for sealing with which the film covering electronic component mounting substrate for sealing shown in FIG. 1 is provided. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the film for sealing with which the film-covering electronic component mounting substrate for sealing shown in FIG. 1 is provided. It is a longitudinal cross-sectional view for demonstrating the manufacturing method of the film covering electronic component mounting board | substrate for sealing shown in FIG.

  Hereinafter, the film-covered electronic component mounting substrate for sealing of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

  FIG. 1 is a longitudinal sectional view showing an embodiment of a sealing film-covered electronic component mounting substrate according to the present invention, and FIG. 2 is a first view of a sealing film provided in the sealing film-covered electronic component mounting substrate shown in FIG. FIG. 3 is a longitudinal sectional view showing a second embodiment of a sealing film provided in the sealing film-covered electronic component mounting substrate shown in FIG. 1. In the following description, for convenience of description, the upper side in FIGS. 1 to 3 is referred to as “upper” and the lower side is referred to as “lower”.

  The sealing film-covered electronic component mounting substrate 50 of the present invention includes an electronic component mounting substrate 45 including the substrate 5 and the electronic component 4, and a resin layer 7 that covers at least a part of the substrate 5 and the electronic component 4. And a sealing film 100 covering at least a part of the substrate 5 and the electronic component 4 with the resin layer 7 interposed therebetween, and the resin layer 7 is composed of a solvent-soluble resin as a main material and is used for sealing. The film 100 is composed of a resin material as a main material, and is characterized in that an elongation at a softening point required in accordance with JIS K 6251 is 150% or more and 3500% or less.

  In the sealing film-covered electronic component mounting substrate 50 having such a configuration, the resin layer 7 covering at least a part of the substrate 5 and the electronic component 4 is composed mainly of a solvent-soluble resin in the present invention. . Thereby, in the film-covered electronic component mounting substrate 50 for sealing, the resin layer 7 is in a state of following the unevenness 6 formed by mounting the electronic component 4 on the substrate 5 with excellent followability, It has become a coating.

  Further, in the present invention, the sealing film 100 covers at least a part of the substrate 5 and the electronic component 4 via the resin layer 7 described above, and is configured with a resin material as a main material. JIS K The elongation at the softening point required according to 6251 is 150% or more and 3500% or less. Therefore, in the sealing film-covered electronic component mounting substrate 50, the sealing film 100 is coated in a state of following the unevenness 6 covered with the resin layer 7 with better followability. It has become.

  Further, in the sealing film-covered electronic component mounting substrate 50 of the present invention, the resin layer 7 composed mainly of a solvent-soluble resin covers at least a part of the substrate 5 and the electronic component 4, Thereby, the permeability | transmittance of moisture (water vapor | steam) is suppressed appropriately. Therefore, even if the sealing film-covered electronic component mounting substrate 50 is applied to, for example, a water meter, an outdoor unit provided in an air conditioner or an electronic device disposed outdoors such as a solar power generation system, Since it is possible to accurately suppress the water vapor from reaching the electronic component 4 included in the sealing film-covered electronic component mounting substrate 50, the occurrence of a failure of the electronic component 4 due to the contact of the water vapor is accurately suppressed. The As a result, the electronic device including the sealing film-covered electronic component mounting substrate 50 has excellent reliability.

  Such a sealing film-covered electronic component mounting substrate 50 includes the electronic component mounting substrate 45, the resin layer 7, and the sealing film 100 as described above. Hereinafter, each of these parts constituting the sealing film-covered electronic component mounting substrate 50 will be described in order.

<Electronic component mounting board 45>
As shown in FIG. 1, the electronic component mounting substrate 45 includes a substrate 5 and an electronic component 4 mounted (mounted) on the substrate 5, and the electronic component mounting substrate 45 includes the substrate 5. By mounting the electronic component 4 on the top, the convex portion 61 formed corresponding to the position where the electronic component 4 is mounted and the position between the electronic components 4 are formed on the substrate 5. Concavities and convexities 6 including the concave portions 62 are formed.

  In addition, although it does not specifically limit as the board | substrate 5, For example, a printed wiring board etc. are mentioned, For example, the semiconductor component, a capacitor | condenser, a coil, a connector, resistance, etc. are mentioned as the electronic component 4.

<Resin layer 7>
The resin layer 7 covers at least a part of the substrate 5 and the electronic component 4 included in the electronic component mounting substrate 45. In this embodiment, the upper surface (one of the substrates 5 on which the electronic component 4 is mounted). The surface 6 is covered with the electronic component 4 on the substrate 5, thereby covering the unevenness 6 formed of the protrusions 61 and 62.

  The resin layer 7 is composed of a solvent-soluble resin as a main material. As will be described in detail in a method for sealing the electronic component mounting substrate 45 described later, the solvent-soluble resin and the solvent-soluble resin are dissolved in a soluble solvent (organic The liquid material containing the solvent is supplied to the upper surface side of the substrate 5 on which the electronic component 4 is mounted, and then dried and solidified. Therefore, the resin layer 7 can be covered in a state of following the unevenness 6 formed by mounting the electronic component 4 on the substrate 5 with excellent followability. In particular, the substrate 5 is provided with an opening and / or a through hole for exposing an electrode (not shown) for electrical connection with the electronic component 4. The resin layer 7 can be formed with excellent density.

  Furthermore, by covering the upper surface of the substrate 5 on which the electronic component 4 is mounted with a resin layer 7 composed mainly of a solvent-soluble resin, the electronic component 4 included in the sealing film-covered electronic component mounting substrate 50 is provided. , It is possible to accurately suppress the arrival of water vapor.

  The solvent-soluble resin is not particularly limited, and examples thereof include polyimide resins, polyamideimide resins, fluorinated aromatic polymers, (meth) acrylic resins, polyamide resins, aramid resins, polysulfone resins, polyolefin elastomers, and cycloolefin polymers. Examples thereof include polyolefin-based resins, epoxy-based resins, urethane resins, phenol-based resins, and the like, and one or more of these can be used in combination. Among these, at least one of (meth) acrylic resin, polyolefin elastomer, and urethane resin is preferable. Accordingly, the resin layer 7 can be formed with excellent adhesion to the substrate 5 and the electronic component 4, and the water vapor reaches the electronic component 4 provided in the sealing film-covered electronic component mounting substrate 50. The water vapor barrier property which suppresses this can be exhibited more remarkably.

  The solvent (solvent) is appropriately selected according to the type of solvent-soluble resin to be used. For example, acetone, methyl ethyl ketone, methyl isobutyl ketone, DIBK (diisobutyl ketone), cyclohexanone, DAA (diacetone alcohol), etc. Ketones, aromatic hydrocarbons such as benzene, xylene, toluene, alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butyl alcohol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, Cellosolve such as BCSA (butyrocellosolve acetate), NMP (N-methyl-2-pyrrolidone), THF (tetrahydrofuran), DMF (dimethylformamide), DBE (dibasic acid ester) Tellurium), EEP (ethyl 3-ethoxypropionate), DMC (dimethyl carbonate), etc., and one or more of these can be used, either a single solvent or a mixed solvent. Good.

  The average thickness of the resin layer 7 is preferably 1 μm or more and 50 μm or less, and more preferably 30 μm or more and 40 μm or less. By setting the average thickness of the resin layer 7 within this range, the unevenness 6 can be reliably covered with the resin layer 7 and the thickness of the formed film-covered electronic component mounting substrate 50 for sealing is formed. The enlargement in the direction can be accurately suppressed.

<Sealing film 100>
The sealing film 100 covers at least a part of the substrate 5 and the electronic component 4 included in the electronic component mounting substrate 45 through the resin layer 7. In this embodiment, the electronic component 4 is mounted. Almost the entire upper surface (one surface) of the substrate 5 is covered with the resin layer 7, whereby the convex portion 61 and the concave portion formed by mounting the electronic component 4 on the substrate 5 are covered. The unevenness 6 composed of 62 is covered via the resin layer 7.

  In the present invention, the sealing film 100 is composed of a resin material as a main material, and has an elongation at a softening point required in accordance with JIS K 6251 of 150% or more and 3500% or less. By having the film 100 for sealing within such a range, as described in detail in the method for sealing the electronic component mounting substrate 45 described later, excellent follow-up to the unevenness 6 covered with the resin layer 7 is achieved. The film 100 for sealing can be coat | covered in the state which followed with property.

  Such a sealing film 100 may be composed of any resin material as long as the elongation is within the above range. Examples of the resin material include low-density polyethylene, Density polyethylene, ethylene copolymer, polyolefin resin such as stretched polypropylene and unstretched polypropylene, ionomer resin, polyester resin such as polyethylene terephthalate and polybutylene terephthalate, polycarbonate resin, polystyrene resin, acrylic resin, nylon-6 Nylon-6, nylon-6,10, nylon-6T composed of hexamethylenediamine and terephthalic acid, nylon-6I composed of hexamethylenediamine and isophthalic acid, nylon-9T composed of nonanediamine and terephthalic acid, Mechi Polyamide-based resins such as nylon-M5T composed of pentadiamine and terephthalic acid, nylon-6,12 composed of caprolactam and lauryl lactam, nylon-6-6,6 composed of hexamethylenediamine, adipic acid and caprolactam, Examples thereof include thermoplastic resins such as polyvinyl chloride and polyvinyl alcohol, and a single layer body including at least one of them or a multilayer body may be used.

  Further, the resin material included in the sealing film 100 may be a thermosetting resin such as an epoxy resin, a phenol resin, a melamine resin, or a silicone resin, an acrylic resin, or a urethane resin in addition to the thermoplastic resin material described above. A UV curable resin may be included.

  Among these, the sealing film 100 is preferably a single-layer body containing a polyolefin resin as a main material or a multilayer body having one or more layers containing a polyolefin resin as a main material. It is more preferable that the multilayer body has one or more layers containing a main resin as a main material. Thereby, the elongation at the softening point of the sealing film 100 can be easily set to 150% or more and 3500% or less.

  Hereinafter, an example of the sealing film 100 composed of a multilayer body having one or more layers containing a polyolefin-based resin as a main material will be described. In the following first embodiment, a multilayer body composed of four layers will be described, but the present invention is not particularly limited to a multilayer body composed of four layers.

<< First Embodiment >>
As shown in FIG. 2, in this embodiment, the sealing film 100 includes an outermost layer 11, an intermediate layer 12, an intermediate layer 13, and an innermost layer 14, which are the electronic components to be covered shown in FIG. 1. It is comprised with the laminated body laminated | stacked in this order from the other side of the mounting substrate 45. FIG.

  The outermost layer 11 is for imparting an oxygen gas barrier property to the sealing film 100 and is a layer containing an oxygen gas barrier resin.

  As this oxygen gas barrier resin, in this embodiment, the ethylene content to be copolymerized is 27 to 44 mol in an ethylene-vinyl alcohol copolymer saponified product (hereinafter sometimes abbreviated as “EVOH”). % Is preferable.

  Further, the average thickness of the outermost layer 11 is preferably 1 μm or more and 30 μm or less, and more preferably 5 μm or more and 15 μm or less. By setting the average thickness of the outermost layer 11 within such a range, the sealing film 100 can be reliably imparted with an oxygen gas barrier property, and the elongation at the softening point of the sealing film 100 is 150% or more and 3500. % Can be reliably set within the range of% or less.

  In addition, when it is not necessary to give oxygen gas barrier property to the film 100 for sealing, you may abbreviate | omit formation of the outermost layer 11 in the film 100 for sealing.

  The intermediate layer 12 has an elongation rate at the softening point of the sealing film 100 set to 150% or more and 3500% or less, and is excellent in adhesion to the unevenness 6 and shape followability. It is a layer containing an ionomer resin as a main material for the purpose of making the stopping film 100 excellent in toughness.

  Here, in this specification, the ionomer resin is a binary copolymer having ethylene and (meth) acrylic acid as a constituent component of the polymer, ethylene, (meth) acrylic acid, and (meth) acrylic acid ester. Is a resin crosslinked with metal ions, and one or two of them can be used in combination.

Examples of the metal ion include potassium ion (K ⁺ ), sodium ion (Na ⁺ ), lithium ion (Li ⁺ ), magnesium ion (Mg ⁺⁺ ), and zinc ion (Zn ⁺⁺ ). Among these, sodium ions (Na ⁺ ) or zinc ions (Zn ⁺⁺ ) are preferable. Thereby, since the crosslinked structure in the ionomer resin is stabilized, the function as the intermediate layer 12 described above can be exhibited more remarkably.

  Further, a binary copolymer having ethylene and (meth) acrylic acid as constituent components of the polymer, or a ternary copolymer having ethylene, (meth) acrylic acid and (meth) acrylic acid ester as constituent components of the polymer. The degree of neutralization by the cation (metal ion) in the carboxyl group of the polymer is preferably 40 mol% or more and 75 mol% or less.

  Moreover, as for the intermediate | middle layer 12, it is more preferable that melting | fusing point (based on JIS K-7121, measured by DSC method) is 100 degrees C or less, and tensile fracture stress (measured based on JIS K-7162) is 40 MPa or less. Thereby, in the manufacturing method of the film covering electronic component mounting board | substrate 50 mentioned later, the board | substrate 5 and the electronic component 4 are easily implemented through the resin layer 7 using the film 100 for sealing. Can do.

  The average thickness of the intermediate layer 12 is preferably 1 μm or more and 30 μm or less, and more preferably 5 μm or more and 15 μm or less. By setting the average thickness of the intermediate layer 12 within such a range, the sealing film 100 is excellent in toughness, and the elongation at the softening point of the sealing film 100 is in the range of 150% to 3500%. It can be assumed that it is securely set within.

  In the present embodiment, the intermediate layer 13 is an ethylene-vinyl acetate copolymer as an ethylene copolymer for the purpose of setting the elongation at the softening point of the sealing film 100 to 150% or more and 3500% or less. It is a layer containing a polymer as a main material.

  Moreover, as this ethylene-vinyl acetate copolymer, the VA content to be copolymerized is preferably 5% by weight to 30% by weight, and more preferably 10% by weight to 20% by weight. If it is less than the lower limit, it may be difficult to set the elongation at the softening point of the sealing film 100 within the above range. On the other hand, when the upper limit is exceeded, the crystal part of the resin constituting the intermediate layer 13 decreases and the non-crystal part tends to increase, so that the sealing film 100 is changed to the innermost layer. Even if it is set as the structure provided with 14, there exists a possibility that additives, such as antioxidant remaining in the intermediate | middle layer 13, may elute. Therefore, it passes through the innermost layer 14 and moves to the electronic component mounting substrate 45 side. As a result, there is a possibility that the characteristics of the electronic component 4 may be inconvenient. Moreover, since the melting point tends to decrease, the heat resistance of the sealing film 100 may also decrease.

  The average thickness of the intermediate layer 13 is preferably 5 μm or more and 130 μm or less, and more preferably 20 μm or more and 80 μm or less. By setting the average thickness of the intermediate layer 13 within such a range, the elongation at the softening point of the sealing film 100 can be reliably set within the range of 150% to 3500%.

  The intermediate layer 12 and the intermediate layer 13 may be laminated in this order from the outermost layer 11 side, or the intermediate layer 13 and the intermediate layer 12 may be laminated in this order from the outermost layer 11 side. .

  When the intermediate layer 13 includes an additive such as an antioxidant, the innermost layer 14 suppresses the migration of the additive to the electronic component mounting substrate 45 side due to the dissolution of the additive from the intermediate layer 13. Or it is a layer which contains ethylene type heat sealable resin as a main material for the purpose of functioning as a blocking layer to prevent.

  The innermost layer 14 is a layer that is in close contact (contact) with the resin layer 7 that covers the electronic component 4 and the substrate 5 when the electronic component mounting substrate 45 is covered with the sealing film 100. It functions as a layer for heat-sealing 100 to the resin layer 7.

  As the ethylene-based heat-sealable resin contained in the innermost layer 14, in this embodiment, the density measured by the method defined in JIS K7112 is in the range of 0.890 to 0.910, and in JIS K7206 A linear low-density polyethylene resin (LLDPE) having a Vicat softening point of 90 ° C. or less measured by a method to be defined is preferably used.

  Further, the innermost layer 14 may contain a lubricant in addition to the ethylene heat sealable resin. In that case, as the lubricant, organic lubricants such as behenic acid amide, oleic acid amide and erucic acid amide, and inorganic lubricants such as silica, zeolite and calcium carbonate are preferably used, and one or more of these are used. Can be used in combination. The addition amount is preferably 0.1 to 5% by weight, and is usually added in the form of a masterbatch.

  The average thickness of the innermost layer 14 is preferably 1 μm or more and 20 μm or less, and more preferably 5 μm or more and 15 μm or less. By setting the average thickness of the innermost layer 14 within this range, the innermost layer 14 can be reliably provided with the function as the blocking layer, and the elongation at the softening point of the sealing film 100 is 150%. It can be reliably set within the range of 3500% or less.

  The additive such as an antioxidant is eluted from the intermediate layer 13 mainly when the sealing film 100 is heated by driving the electronic component 4 or the like. With the configuration including the innermost layer 14, the heat resistance of the sealing film-covered electronic component mounting substrate 50 that is configured by covering the electronic component mounting substrate 45 with the sealing film 100 shown in FIG. 1 can be improved. Can be planned.

  Further, in the intermediate layer 13 provided in the sealing film 100, elution of additives such as antioxidants is suppressed or prevented, and when the sealing performance by the intermediate layer 13 is ensured, The formation of the innermost layer 14 may be omitted.

  Further, in the sealing film 100, adhesion is imparted between the outermost layer 11 and the intermediate layer 12, between the intermediate layer 12 and the intermediate layer 13, and between the intermediate layer 13 and the innermost layer 14. Alternatively, an adhesive layer may be provided as necessary to enhance the adhesiveness. In particular, since the adhesive strength between the outermost layer 11 and the intermediate layer 12 or between the intermediate layer 12 and the intermediate layer 13 is weak even in the film forming process by coextrusion, an adhesive layer is disposed between the two layers. It is preferable.

  Examples of the adhesive resin contained in the adhesive layer include EVA, ethylene-maleic anhydride copolymer, EAA, EEA, ethylene-methacrylate-glycidyl acrylate terpolymer, or various polyolefins such as acrylic acid, methacrylic acid. Monobasic unsaturated fatty acids such as acids, dibasic unsaturated fatty acids such as maleic acid, fumaric acid, itaconic acid or the like grafted with these anhydrides, such as maleic acid grafted EVA, maleic acid grafted ethylene Known materials such as -α-olefin copolymers, styrene elastomers, acrylic resins, epoxy resins, and urethane resins can be used as appropriate.

  In addition, when it is set as the structure which inserts an adhesive layer between the outermost layer 11 and the intermediate | middle layer 12, or between the intermediate | middle layer 12 and the intermediate | middle layer 13, the laminated body of an adhesive layer and the intermediate | middle layer 12 is these adhesive layers. And the intermediate layer 12 may be repeated, and the laminate of the adhesive layer and the intermediate layer 13 may be a repeated body in which the adhesive layer and the intermediate layer 13 are repeatedly stacked. May be.

  Further, in the sealing film 100 of the present embodiment configured as described above, the outermost layer 11, the intermediate layer 13, and the innermost layer 14 constitute a layer containing a polyolefin-based resin as a main material.

<< Second Embodiment >>
In addition to the case where the sealing film 100 is formed of a multilayer body having one or more layers containing a polyolefin-based resin as a main material as in the first embodiment, for example, the sealing film 100 Can be constituted by a multilayer body having one or more layers containing a polyamide-based resin as a main material. Examples of such a case include the following.

  As shown in FIG. 3, in this embodiment, the sealing film 100 includes an outermost layer 21, an intermediate layer 22, an intermediate layer 23, and an innermost layer 24, which are opposite to the electronic component mounting substrate 45 to be covered. It is comprised from the laminated body laminated | stacked in this order from the side.

  The outermost layer 21 is for imparting heat resistance to the outside of the sealing film-covered electronic component mounting substrate 50 in which the electronic component mounting substrate 45 is coated with the sealing film 100. It is a layer containing at least one kind of linear low density polyethylene.

  As the soft vinyl chloride resin, a vinyl chloride homopolymer having an average degree of polymerization of 700 to 1800, an ethylene-vinyl chloride copolymer having an ethylene content of 10% or less, or an ethylene-vinyl acetate copolymer content of 12% or less. An ethylene-vinyl acetate-vinyl chloride graft copolymer can be used, and further, a mixture obtained by adding 40 parts by weight or more and 70 parts by weight or less of a plasticizer based on 100 parts by weight of the mixture as a base resin can be used. .

  As the plasticizer, known ones such as phthalic acid, phosphoric acid, aliphatic, polyester, trimellitic acid, and pyromellitic acid can be used.

  In addition, the outermost layer 21 may contain a stabilizer, a lubricant, a processing aid, a secondary plasticizer / stabilizer, and the like.

The linear low-density polyethylene is not particularly limited, and for example, a copolymer obtained by copolymerizing hexene or octene with ethylene has a density of 0.935 g / cm ² or less, a melting point of 120 ° C. or more, and a softening point of 110 ° C. or more. Those are preferably used.

  By making the outermost layer 21 to have such a configuration, the sealing film 100 can have excellent heat resistance, and the elongation at the softening point of the sealing film 100 is 150% or more and 3500% or less. Can be set.

  Moreover, the average thickness of the outermost layer 21 is preferably 5 μm or more and 60 μm or less, and more preferably 10 μm or more and 40 μm or less. By setting the average thickness of the outermost layer 21 within such a range, heat resistance can be reliably imparted to the sealing film 100, and the elongation at the softening point of the sealing film 100 is 150% or more and 3500%. It can be reliably set within the following range.

  When the sealing film 100 is not required to consider the heat resistance of the sealing film-covered electronic component mounting substrate 50, the formation of the outermost layer 21 in the sealing film 100 is omitted. May be.

  The intermediate layer 22 is a layer containing a polyamide-based resin as a main material for the purpose of setting the elongation at the softening point of the sealing film 100 to 150% or more and 3500% or less.

  In addition, as the polyamide-based resin, for example, nylon-6,12 composed of caprolactam and lauryllactam, or nylon-6-6,6 composed of hexamethylenediamine, adipic acid and caprolactam, the ratio of 6-nylon Is preferably a copolymer nylon such as those having a ratio of 30% to 90%. By using such copolymer nylon, the elongation at the softening point of the sealing film 100 can be reliably set within the above range.

  Further, it is more preferable that the ratio of 6-nylon in the copolymer nylon is 50% or more and 85% or less, the melting point is 200 ° C. or less, and the weight average molecular weight is 20,000 or more. Thereby, since the fall of the moderate melt viscosity of the intermediate | middle layer 22 is aimed at, while being able to set the elongation rate in the softening point of the film 100 for sealing more reliably within the said range, at the time of manufacture of the film 100 for sealing The film formability of the intermediate layer 22 can be maintained.

  The average thickness of the intermediate layer 22 is preferably 1 μm or more and 40 μm or less, and more preferably 5 μm or more and 20 μm or less. By setting the average thickness of the intermediate layer 22 within such a range, the elongation at the softening point of the sealing film 100 can be reliably set within the range of 150% to 3500%.

  The intermediate layer 23 is for imparting oxygen gas barrier properties to the sealing film 100 and is a layer containing an oxygen gas barrier resin.

  As the oxygen gas barrier resin, the ethylene content to be copolymerized in the saponified ethylene-vinyl alcohol copolymer is 27 to 44 mol%, as in the outermost layer 11 of the first embodiment. It is preferable that.

  The average thickness of the intermediate layer 23 is preferably 1 μm or more and 30 μm or less, and more preferably 5 μm or more and 15 μm or less. By setting the average thickness of the intermediate layer 23 within this range, the sealing film 100 can be reliably imparted with an oxygen gas barrier property, and the elongation at the softening point of the sealing film 100 is 150% or more and 3500. % Can be reliably set within the range of% or less.

  The intermediate layer 22 and the intermediate layer 23 may be laminated in this order from the outermost layer 21 side, or the intermediate layer 23 and the intermediate layer 22 may be laminated in this order from the outermost layer 21 side. .

  Further, when it is not necessary to provide the sealing film 100 with an oxygen gas barrier property, the formation of the intermediate layer 23 in the sealing film 100 may be omitted.

  The innermost layer 24 is a layer that is in close contact (contact) with the resin layer 7 that covers the electronic component 4 and the substrate 5 when the electronic component mounting substrate 45 is covered with the sealing film 100. For the purpose of causing the resin layer 7 to function as a layer for heat sealing, it is a layer containing an ethylene-based heat sealing resin as a main material.

  As the ethylene-based heat-sealable resin contained in the innermost layer 24, the same materials as those mentioned for the innermost layer 14 of the first embodiment can be used.

  The average thickness of the innermost layer 24 is preferably 1 μm or more and 20 μm or less, and more preferably 5 μm or more and 15 μm or less. By setting the average thickness of the innermost layer 24 within such a range, the elongation at the softening point of the sealing film 100 can be reliably set within the range of 150% to 3500%.

  The additive such as an antioxidant is eluted from the intermediate layer 23 mainly when the sealing film 100 is heated by driving the electronic component 4 or the like. With the configuration including the innermost layer 24, the heat resistance of the sealing film-covered electronic component mounting substrate 50 having a configuration in which the electronic component mounting substrate 45 is covered with the sealing film 100 can be improved.

  In addition, in the sealing film 100, when the sealing performance with respect to the board | substrate 5 can be ensured by the intermediate | middle layer 23, formation of the innermost layer 24 in the sealing film 100 may be abbreviate | omitted.

  Further, in the sealing film 100, as in the first embodiment, between the outermost layer 21 and the intermediate layer 22, between the intermediate layer 22 and the intermediate layer 23, and between the intermediate layer 23 and the innermost layer 24. In order to give adhesiveness or to improve adhesiveness, an adhesive layer may be provided as necessary.

  In addition, when it is set as the structure which inserts an adhesive layer between the outermost layer 21 and the intermediate | middle layer 22, or between the intermediate | middle layer 22 and the intermediate | middle layer 23, the laminated body of an adhesive layer and the intermediate | middle layer 22 is these adhesive layers. The intermediate layer 22 may be a repeated body in which the adhesive layer and the intermediate layer 23 are repeatedly stacked. The stacked body of the adhesive layer and the intermediate layer 23 may be a repeated body in which the adhesive layer and the intermediate layer 23 are repeatedly stacked. May be.

  Further, in the sealing film 100 of the present embodiment configured as described above, the intermediate layer 22 forms a layer containing a polyamide-based resin as a main material.

  Further, the production method for producing the sealing film 100 of the first embodiment and the second embodiment is not particularly limited, and for example, a known coextrusion method, a dry laminating method, etc. are used for film formation and It can be obtained by laminating.

  Here, by forming the sealing film 100 with the multilayer body shown in the first and second embodiments, the elongation at the softening point of the sealing film 100 is 150% or more relatively easily. Although it can be set to 3500% or less, this elongation may be 150% or more and 3500% or less, but is preferably 150% or more and 3000% or less, and is preferably 500% or more and 2000% or less. More preferred. Thus, when the sealing film 100 is used for covering the unevenness 6 covered with the resin layer 7, sealing with excellent followability to the shape of the unevenness 6 covered with the resin layer 7 is achieved. It can coat | cover in the state which carried out, and can suppress or prevent that the film 100 for sealing is fractured on the way.

  In addition, by setting the elongation at the softening point of the sealing film 100 within the above range, even if the step in the unevenness 6 covered with the resin layer 7 is large such as 10 mm or more, the sealing film 100 is sealed. The stop film 100 can be made to follow the shape of the irregularities 6.

  The elongation at break (elongation at the softening point) can be measured according to the method described in JIS K 6251 using an autograph device (for example, AUTOGRAPH AGS-X manufactured by Shimadzu Corporation). it can.

  The softening point of the sealing film 100 is determined using a dynamic viscoelasticity measuring apparatus (for example, EXSTAR6000, manufactured by Seiko Instruments Inc.) with a distance between chucks of 20 mm, a heating rate of 5 ° C., and an angular frequency of 10 Hz. It can be measured under conditions.

  Furthermore, the linear expansion coefficient in the temperature range of 25 ° C. or more and 80 ° C. or less of the sealing film 100 is preferably 100 ppm / K or less, and more preferably 5 ppm / K or more and 50 ppm / K or less. When the linear expansion coefficient in the temperature range of 25 ° C. or higher and 80 ° C. or lower of the sealing film 100 is a value in such a range, the sealing film 100 is excellent when the sealing film 100 is heated. Since it has a stretching property, the shape followability with respect to the unevenness 6 covered with the resin layer 7 of the sealing film 100 can be improved more reliably. Furthermore, since excellent adhesiveness can be maintained between the sealing film 100 and the resin layer 7, the sealing film 100 resulting from heat generated by repeating the driving of the electronic component mounting substrate 45. The peeling from the resin layer 7 (electronic component mounting substrate 45) can be suppressed or prevented more accurately. The linear expansion coefficient of the sealing film 100 can be calculated using, for example, a dynamic viscoelasticity measuring apparatus (for example, EXSTAR6000 manufactured by Seiko Instruments Inc.).

Further, the storage elastic modulus at 80 ° C. of the sealing film 100 is preferably 1 × 10 ⁵ Pa or more, and more preferably 2 × 10 ⁵ Pa or more and 9 × 10 ⁸ Pa or less. Accordingly, when the unevenness 6 covered with the resin layer 7 is covered with the sealing film 100, the sealing film 100 is more reliably associated with the shape of the unevenness 6 covered with the resin layer 7. Can be followed. Therefore, since the sealing film 100 can be coated with better adhesion (airtightness) to the unevenness 6 covered with the resin layer 7, moisture, dust, etc. can be obtained by covering the sealing film 100. The barrier property against external factors can be improved more reliably. The storage elastic modulus at 80 ° C. of the sealing film 100 is determined by using a dynamic viscoelasticity measuring device (for example, EXSTAR6000, manufactured by Seiko Instruments Inc.), a distance between chucks of 20 mm, and a heating rate of 5 ° C./min. In addition, measurement can be performed under conditions of an angular frequency of 10 Hz.

  The average thickness of the sealing film 100 as a whole is preferably 10 μm or more and 200 μm or less, and more preferably 20 μm or more and 150 μm or less. By setting the average thickness of the sealing film 100 within this range, the sealing film 100 can be accurately suppressed or prevented from breaking in the middle of the sealing film 100, and for sealing. The elongation at the softening point of the film 100 can be reliably set within a range of 150% to 3500%.

Further, the water vapor permeability in the laminate of the sealing film 100 and the resin layer 7 is preferably 4.0 g / m ² · 24 hr (40 ° C., 90% RH) or less, preferably 0.1 g / m ^2. It is preferably 24 hr (40 ° C., 90% RH) or more and 2.5 g / m ² · 24 hr (40 ° C., 90% RH) or less. Accordingly, it is possible to accurately suppress the water vapor from reaching the electronic component 4 included in the sealing film-covered electronic component mounting substrate 50. Therefore, it is possible to accurately detect the occurrence of the failure of the electronic component 4 due to the contact of the water vapor. Therefore, the electronic device including the sealing film-covered electronic component mounting substrate 50 can have excellent reliability.

<Manufacturing Method of Film Covering Electronic Component Mounting Board 50 for Sealing>
Next, a manufacturing method for manufacturing the above-described sealing film-covered electronic component mounting substrate 50, that is, a sealing method of the electronic component mounting substrate 45 using the resin layer 7 and the sealing film 100 will be described.

  The manufacturing method of the sealing film-covered electronic component mounting substrate 50 of the present embodiment includes a coating step of coating the substrate 5 and the electronic component 4 with the resin layer 7, and the substrate 5 and the electronic component 4 coated with the resin layer 7. Placing the sealing film 100 so as to cover, heating and softening the sealing film 100, heating and decompressing the pressure, and cooling and pressurizing the sealing film 100. And a cooling / pressurizing step of covering the substrate 5 covered with the resin layer 7 and the electronic component 4 with the sealing film 100.

  FIG. 4 is a longitudinal sectional view for explaining a method of manufacturing the sealing film-covered electronic component mounting substrate shown in FIG.

  Hereinafter, each process of the manufacturing method of the film covering electronic component mounting board | substrate 50 for sealing is demonstrated sequentially.

(Coating process)
First, as shown in FIG. 4A, an electronic component mounting substrate 45 including a substrate 5 and an electronic component 4 mounted on the upper surface (one surface) of the substrate 5 is prepared, and then the electronic component mounting substrate is prepared. Substrate 5 and electronic component 4 exposed on substantially the entire upper surface side of 45, that is, on the upper surface side of electronic component mounting substrate 45, are covered with resin layer 7 composed mainly of a solvent-soluble resin (FIG. 4 ( b)).

  The resin layer 7 that covers the substrate 5 and the electronic component 4 is formed by applying a liquid material containing a solvent-soluble resin and a solvent (organic solvent) soluble in the solvent-soluble resin to the upper surface of the substrate 5 on which the electronic component 4 is mounted. This is provided by drying and solidifying the liquid material after the substrate 5 and the electronic component 4 that are exposed on the upper surface side of the substrate 5 are coated with the liquid material. Since the resin material 7 is provided by drying and solidifying the liquid material in a state in which the substrate 5 and the electronic component 4 are coated (coated) with such a liquid material, the electronic component 4 is mounted on the substrate 5. The resin layer 7 is formed in a state of following the unevenness 6 formed thereby with excellent followability.

  Further, the substrate 5 (printed wiring board) is provided with an opening and / or a through-hole for exposing an electrode (not shown) for electrical connection with the electronic component 4. By forming the resin layer 7 by drying and solidifying the material, the resin layer 7 can be formed with excellent denseness up to these openings and through holes.

  As a method of supplying the liquid material to the upper surface side of the substrate 5 on which the electronic component 4 is mounted, for example, a method of immersing the electronic component mounting substrate 45 in the liquid material (immersion method), an upper surface side of the electronic component mounting substrate 45 In addition, there are a method of spraying (spraying) a liquid material (a spraying method), a method of applying a liquid material to the upper surface side of the electronic component mounting substrate 45 (a coating method), and the like. According to the spraying method or the coating method, which is preferable, the liquid material can be selectively supplied to the upper surface side of the electronic component mounting substrate 45 relatively easily.

(Arrangement process / heating / decompression process)
Next, as shown in FIG. 4C, after the sealing film 100 is disposed on the electronic component mounting substrate 45 so as to cover the substrate 5 covered with the resin layer 7 and the electronic component 4 (arrangement step). ), The sealing film 100 is heated and softened, and the pressure is reduced (heating / decompression step; see FIG. 4D).

  Thus, by heating the sealing film 100, the sealing film 100 is softened, and as a result, the sealing film 100 can follow the shape of the unevenness 6 covered with the resin layer 7.

  At this time, the electronic component mounting substrate 45 and the sealing film 100 are arranged in a reduced-pressure atmosphere, so that not only the upper side of the sealing film 100 but also the electronic component mounting substrate 45 and the sealing film 100 The gas (air) in between is degassed.

  Thereby, it will be in the state which followed the shape of the unevenness | corrugation 6 coat | covered with the resin layer 7 a little while extending the film 100 for sealing.

  By this step, the sealing film 100 can be made to follow the shape of the irregularities 6 covered with the resin layer 7.

  The heating of the sealing film 100 and the reduced pressure of the atmosphere may be reduced after the heating or may be heated after the reduced pressure, but the heating and the reduced pressure are preferably performed almost simultaneously. Thereby, the softened film 100 for sealing can be made into the state which followed the shape of the unevenness | corrugation 6 coat | covered with the resin layer 7 a little reliably.

(Cooling / pressurization process)
Next, as shown in FIG. 4E, the sealing film 100 is cooled and pressurized.

  Thus, by pressurizing from the decompressed atmosphere, in the heating and decompression step, the space between the electronic component mounting substrate 45 and the sealing film 100 is degassed, and the decompressed state is maintained. As a result, the sealing film 100 is further extended. As a result, the sealing film 100 in a softened state follows the shape of the unevenness 6 covered with the resin layer 7 with excellent adhesion (air density). Thus, the substrate 5 and the electronic component 4 are covered.

  At this time, in the present invention, the elongation at the softening point of the sealing film 100 is 150% or more and 3500% or less. Therefore, since the sealing film 100 can be extended with better shape followability with respect to the irregularities 6 covered with the resin layer 7 during this pressurization, the sealing film 100 in a softened state is used. The resin layer 7 can be coated with excellent adhesion.

  Then, the sealing film 100 is cooled in a state where the resin layer 7 is coated with excellent adhesiveness (airtightness) by the sealing film 100, and the sealing film is maintained while maintaining this state. 100 solidifies.

  In particular, in the present embodiment, the resin layer 7 is formed so as to cover almost the entire upper surface of the substrate 5 and the electronic component 4 mounted on the substrate 5. By forming such a resin layer 7 on the upper surface side of the electronic component mounting substrate 45, the upper surface side of the substrate 5 is placed on the resin layer without forming a gap as between the electronic component 4 and the substrate 5. 7 can be constituted by a continuous surface. Therefore, the unevenness 6 covered with the resin layer 7 can be covered with the sealing film 100 in a state of following with better followability.

  Moreover, since the magnitude | size of the level | step difference formed can be made small compared with the case where formation of the resin layer 7 is abbreviate | omitted by coat | covering the resin layer 7 with respect to the unevenness | corrugation 6, from this viewpoint, The unevenness 6 covered with the resin layer 7 can be covered with the sealing film 100 in a state of following with better followability.

  By this process as described above, the sealing film-covered electronic component mounting substrate 50 that is coated with excellent adhesion by the sealing film 100 corresponding to the shape of the unevenness 6 covered with the resin layer 7 is obtained. be able to. Therefore, in the sealing film-covered electronic component mounting substrate 50, it is possible to accurately suppress or prevent the electronic component 4 from coming into contact with external factors such as moisture and dust. Accordingly, the reliability of the obtained electronic device including the sealing film-covered electronic component mounting substrate 50 and thus the sealing film-covered electronic component mounting substrate 50 can be improved.

  In addition, although cooling of the film 100 for sealing and pressurization of atmosphere may cool after pressurization, it is preferable to perform cooling and pressurization substantially simultaneously. Thereby, the film 100 for sealing can be coat | covered with the more excellent adhesiveness corresponding to the shape of the unevenness | corrugation 6. FIG.

  Through the above steps, the substrate 5 and the electronic component 4 are sealed with the sealing film-covered electronic component mounting substrate 50 covered in this order from the substrate 5 side by the resin layer 7 and the sealing film 100. Can be obtained.

  Although the sealing film-covered electronic component mounting substrate of the present invention has been described above, the present invention is not limited to these.

  For example, in the above-described embodiment, the case where the resin layer is formed on almost the entire upper surface of the substrate and all of the substrate and the electronic component exposed on the upper surface of the substrate are covered with the resin layer has been described. Without being limited, the resin layer may cover a part of the substrate and the electronic component on the upper surface side of the substrate. Further, the sealing film may be formed so as to selectively cover the resin layer when the resin layer covers a part of the substrate and the electronic component, or substantially on the upper surface side of the substrate. It may be formed so as to cover the entire surface.

  Furthermore, the resin layer may be formed so as to cover almost the whole or part of the lower surface side of the substrate. When the resin layer is formed so as to cover almost the entire lower surface of the substrate, the sealing film is formed so as to cover almost the entire surface of the resin layer. Further, when the resin layer is formed by covering a part of the lower surface side of the substrate, the sealing film only needs to cover the resin layer, and is formed so as to selectively cover the resin layer. It may be formed so as to cover almost the entire lower surface side of the substrate.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to this.

Example 1
<Preparation of liquid material for forming resin layer>
In order to prepare a liquid material for forming a resin layer, a solvent-soluble resin constituting the resin layer to be formed and an organic solvent (solvent) for dissolving the solvent-soluble resin are shown below. Prepared.

  That is, a styrene-isobutylene-styrene triblock copolymer (SIBS, manufactured by Kaneka Co., Ltd., “SIBSTAR062T”) was prepared as a solvent-soluble resin.

Moreover, toluene was prepared as an organic solvent.
Next, a liquid material was prepared by dissolving SIBS in toluene.

<Manufacture of sealing film>
In order to obtain the sealing film 100, the following resins were prepared as the resins constituting each layer of the sealing film to be formed.

That is, as the resin constituting the outermost layer 11, EVOH (manufactured by Kuraray, “EVAL SP295B”, density 1.13 g / cm ³ , melt index 5.5 g / 10 min (measured at 190 ° C.), melting point 163 ° C., ethylene content 44 Mol%).

Further, as a resin constituting the intermediate layer 13, an adhesive resin (manufactured by Mitsui Chemicals, “Admer NF536”, density 0.905 kg / m ³ , MFR 3.5 g / 10 min (190 ° C. measurement), melting point 120 ° C.) was prepared.

Further, as a resin constituting the intermediate layer 12, an ionomer resin (manufactured by Mitsui DuPont Polychemicals, “Himiran 1855”, density 0.940 kg / m ³ , MFR 1.3 g / 10 min (measured at 190 ° C.), melting point 97 ° C.) is prepared. did.

Moreover, as resin which comprises the innermost layer 14, ethylene-vinyl acetate copolymer resin (Mitsui DuPont polychemical make, "Evaflex V5714RC", density 0.940kg / m < ³ >, MFR2.8g / 10min (190 degreeC measurement), Melting point 89 ° C., vinyl acetate content 16% by weight).

  Next, the outermost layer 11 / intermediate layer is formed by coextrusion using the resin constituting the outermost layer 11, the resin constituting the intermediate layer 12, the resin constituting the intermediate layer 13, and the resin constituting the innermost layer 14. The film for sealing of Example 1 comprised with the laminated body laminated | stacked in order of 13 / intermediate layer 12 / innermost layer 14 was obtained.

  The average thickness (μm) of each layer of the obtained sealing film of Example 1 was 13/9/13/65 μm from the outermost layer 11, and the total thickness was 100 μm.

  Moreover, it was 1200% when the elongation rate in the softening point of the film for sealing of Example 1 was measured.

  Furthermore, when the linear expansion coefficient in the temperature range of 25 degreeC or more and 80 degrees C or less in the film for sealing of Example 1 was measured, it was 20 ppm / K.

Moreover, it was 2 * 10 < ⁷ > Pa when the storage elastic modulus in 80 degreeC of the film for sealing was measured.

<Manufacture of film-coated electronic component mounting substrate for sealing>
First, an arbitrary electronic component mounting substrate is prepared, and then the prepared liquid material is supplied to the upper surface side of the substrate on which the electronic component is mounted, and then dried and solidified, whereby the electronic component mounting substrate 45 is A resin layer 7 covering the exposed substrate 5 and the electronic component 4 was formed.
The formed resin layer had an average thickness (μm) of 35.0 μm.

  Next, in a chamber provided in the skin pack packaging machine (“HI-750 series” manufactured by Hipack Co., Ltd.), the substrate and the electronic component that the electronic component mounting substrate has are covered via the formed resin layer. The sealing film of Example 1 was disposed.

  Next, the sealing film was heated and softened, and the inside of the chamber was decompressed. In addition, the temperature which heated the film for sealing was 125 degreeC, the pressure of the chamber was 1 kPa, and the conditions of this heating and pressure reduction were hold | maintained for 30 seconds.

  Next, by returning the inside of the chamber to room temperature and normal pressure, the sealing film was cooled and the inside of the chamber was pressurized. As a result, the sealing film-covered electronic component mounting substrate of Example 1 in which the substrate and the electronic component were covered with the sealing film was obtained.

(Example 2)
A sealing film-covered electronic component mounting substrate was obtained in the same manner as in Example 1 except that the sealing film of Example 2 composed only of the intermediate layer 13 of Example 1 was used.

Example 3
A sealing film-covered electronic component mounting substrate was obtained in the same manner as in Example 1 except that the sealing film of Example 3 composed only of the intermediate layer 12 of Example 1 was used.

Example 4
In order to obtain the sealing film, the following resins were prepared as the resin constituting the layer of the sealing film to be formed.

  And the film for sealing of Example 4 was obtained by extrusion method using resin which comprises this layer. In addition, the average thickness (micrometer) of the film for sealing of obtained Example 4 was 100 micrometers.

Polypropylene resin (manufactured by Sumitomo Chemical Co., Ltd., “Nobrene FS2011DG2”, density 0.900 g / cm ³ , melt index 2.0 g / 10 min (230 ° C. measurement), melting point 160 ° C.)

  A sealing film-covered electronic component mounting substrate was obtained in the same manner as in Example 1 except that the sealing film of Example 4 was used.

(Example 5)
In order to obtain the sealing film, as the resin constituting each layer of the sealing film to be formed, the following are prepared, and the outermost layer 21 / intermediate layer 22 / intermediate layer are prepared by coextrusion method. 23 / After obtaining the sealing film of Example 5 composed of a laminate laminated in the order of the innermost layer 24, the sealing film-covered electronic component mounting substrate using the sealing film of Example 5 was obtained. A sealing film-covered electronic component mounting substrate was obtained in the same manner as in Example 1 except that was formed.

As the resin constituting the outermost layer 21, linear low density polyethylene (Ube Maruzen polyethylene, “4040FC”, density 938 g / cm ³ , melt index 3.5 g / 10 min (190 ° C. measurement), melting point 126 ° C.) is prepared. did.

  Furthermore, as a resin constituting the intermediate layer 22, a polyamide resin (manufactured by Ube Industries, “1030B2”, relative viscosity 4.1 (96% sulfuric acid), melting point 220 ° C.) was prepared.

Further, as a resin constituting the intermediate layer 23, EVOH (manufactured by Kuraray, “EVAL J171B”, density 1.18 g / cm ³ , melt index 1.7 g / 10 min (measured at 190 ° C.), melting point 183 ° C., ethylene content 32 Mol%).
Further, the same resin as the outermost layer 21 was prepared as the resin constituting the innermost layer 24.

(Comparative Example 1)
As a sealing film of Comparative Example 1, a commercially available biaxially stretched PET film (manufactured by Toyobo Co., Ltd., brand: E5107) was prepared, and the sealing film-coated electronic component mounted using the sealing film of Comparative Example 1 A sealing film-covered electronic component mounting substrate was obtained in the same manner as in Example 1 except that the substrate was formed.

(Comparative Example 2)
A sealing film-covered electronic component mounting substrate was obtained in the same manner as in Example 1 except that the formation of the resin layer on the electronic component mounting substrate was omitted.

<Evaluation test>
The sealing film-covered electronic component mounting substrate produced in each example and each comparative example was evaluated for shape followability and the presence or absence of wrinkles. Below, these evaluation methods are demonstrated.

<< Shape followability >>
The shape followability was evaluated as follows.

  That is, the sealing film-covered electronic component mounting substrate prepared in each Example and each Comparative Example was determined based on the following evaluation criteria based on the presence or absence of voids in the coated unevenness. The presence or absence of voids was observed using a microscope.

Each code | symbol is as follows, (circle) was set as the pass and x was set as the disqualification.
◎: Covered in a filled state up to the bottom of the step ○: Although some gaps are formed at the bottom of the step,
It can be said that it is covered in a filled state up to almost the bottom of the step. ×: Covered in a state where a clear gap is formed at the bottom of the step.

<< Wrinkle presence >>
The presence or absence of wrinkles was evaluated as follows.
That is, the sealing film-covered electronic component mounting substrate produced in each Example and each Comparative Example was judged based on the following evaluation criteria depending on the presence or absence of wrinkles on the coated top surface. The presence or absence of wrinkles was observed using a microscope.

Each code | symbol is as follows, (circle) was set as the pass and x was set as the disqualification.
A: Wrinkles are not observed on the entire top surface of the sealing film. O: Some wrinkles are observed at positions corresponding to the convex portions on the top surface of the sealing film. X: On the convex portions on the top surface of the sealing film. Obvious wrinkles are observed at corresponding positions

  Furthermore, the water vapor transmission rate and the water vapor transmission (barrier) property were evaluated using the sealing films prepared in each Example and each Comparative Example. Below, this evaluation method is demonstrated.

<< Water vapor permeability >>
By supplying the prepared liquid material to the surface (lower surface) on the side that covers the electronic component mounting substrate of the sealing film produced in each Example and Comparative Example 1, the resin layer ( By forming an average thickness of 35 μm, a laminate of a sealing film and a resin layer was obtained. Thereafter, the water vapor permeability [g / m ² · 24 hr (40 ° C., 90% RH)] of the laminate was measured according to JIS Z 0208.

<< Water vapor transmission (barrier) property (presence or absence of rust generation in copper foil) >>
Prepare a substrate coated with copper foil, then supply the prepared liquid material to the upper surface side of the substrate coated with copper foil, and then dry and solidify the resin layer to cover the substrate and copper foil (Average thickness 35 μm) was formed. Then, the sealing films prepared in each Example and each Comparative Example were respectively applied to the upper surface side of the substrate by pressing under conditions of a roller pressure of 0.5 MPa and a temperature of 130 ° C., and then 80 ° C. It was immersed in hot water for 24 hours and judged based on the following evaluation criteria depending on whether or not rust was generated in the copper foil. In addition, the presence or absence of generation | occurrence | production of rust was observed using the microscope from the film side for sealing. Moreover, about the film for sealing produced in the comparative example 2, the presence or absence of the generation | occurrence | production of the rust in copper foil was observed similarly to the above except having omitted the formation of the resin layer with respect to the board | substrate with which copper foil was coat | covered. did.

Each code | symbol is as follows, (circle) was set as the pass and x was set as the disqualification.
○: No occurrence of rust in copper foil ×: Obvious occurrence of rust in copper foil

  As apparent from Table 1, in the sealing film-covered electronic component mounting substrate of each example, the elongation at the softening point of the sealing film is 150% or more and 3500% or less, and the resin layer is solvent-soluble. By constituting the resin as the main material, it was possible to cover the electronic component mounting substrate without generating a void at the bottom of the recess and further wrinkling on the top surface of the sealing film. Further, the sealing film-covered electronic component mounting substrate of each example showed a result of exhibiting excellent water vapor barrier properties by including a resin layer composed mainly of a solvent-soluble resin.

  On the other hand, in the film-covered electronic component mounting substrate for sealing of Comparative Example 1, the elongation at the softening point is less than 150%. In addition, in the sealing film-covered electronic component mounting substrate of Comparative Example 2, the formation of the resin layer is omitted, and as a result, the electron generated by the sealing film is shown. The results showed that a sufficient water vapor barrier property could not be obtained in the component mounting board.

DESCRIPTION OF SYMBOLS 100 Film for sealing 11 Outermost layer 12 Intermediate layer 13 Intermediate layer 14 Innermost layer 4 Electronic component 5 Substrate 6 Concavity and convexity 7 Resin layer 21 Outermost layer 22 Intermediate layer 23 Intermediate layer 24 Innermost layer 45 Electronic component mounting substrate 50 Covering film for sealing Electronic component mounting board 61 Convex part 62 Concave part

Claims (7)

An electronic component mounting substrate comprising a substrate and an electronic component mounted on the substrate;
A resin layer covering at least a part of the substrate and the electronic component;
A sealing film that covers at least a part of the substrate and the electronic component via the resin layer;
The resin layer is composed mainly of a solvent-soluble resin,
The sealing film is composed of a resin material as a main material, and has an elongation at a softening point required in accordance with JIS K 6251 of 150% or more and 3500% or less. Component mounting board.   2. The sealing film-covered electronic component mounting substrate according to claim 1, wherein the sealing film has a linear expansion coefficient of 100 ppm / ° C. or less in a temperature range of 25 ° C. or more and 80 ° C. or less.   The sealing film-covered electronic component mounting substrate according to claim 1, wherein the sealing film has at least one layer mainly composed of a thermoplastic resin.   4. The sealing film-covered electronic component mounting substrate according to claim 1, wherein the sealing film has an average thickness of 10 μm to 200 μm. 5. The film-covered electronic component mounting substrate for sealing according to claim 1, wherein the sealing film has a storage elastic modulus at 80 ° C. of 1 × 10 ⁵ Pa or more.   The film-covered electronic component mounting substrate for sealing according to any one of claims 1 to 5, wherein the solvent-soluble resin is at least one of a (meth) acrylic resin, a polyolefin elastomer, and a urethane resin.   The film-covered electronic component mounting substrate for sealing according to any one of claims 1 to 6, wherein the substrate is a printed wiring board.

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