JP2016131926A - Coating device, coating method, metal foil-clad substrate, circuit board, electronic component mounting substrate, and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating device and a coating method which can form a thick coating layer without generating air bubbles in the obtained coating layer, and provide a metal foil-clad substrate, a circuit board, an electronic component mounting substrate, and an electronic apparatus which are provided with the coating layer formed by the coating method and have excellent reliability.SOLUTION: A coating device 100 forms a coating layer by coating one surface of a metal foil (a base material sheet) 4A with a liquid material for forming a coating layer by a slot die method, and includes conveying means 40 for conveying the metal foil 4A, and coating means 50 for coating the one surface of the metal foil 4A with the material for forming a coating layer. The coating means 50 includes a first head (a die coater) 52 for forming a first liquid coating film by coating the one surface of the metal foil 4A with the material for forming a coating layer, and a second head (a die coater) 53 which is arranged on a downstream side of a conveyance direction by separating by a predetermined distance and forms a second liquid coating film by coating the one surface of the first liquid coating film with the material for forming a coating layer.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a coating apparatus, a coating method, a metal foil-clad board, a circuit board, an electronic component mounting board, and an electronic device.

  In recent years, a method has been proposed in which a metal foil-clad substrate in which a coating layer made of a resin material is laminated on a metal foil as a circuit board on which electronic components are mounted is obtained by patterning the metal foil. .

  Here, the metal foil-clad substrate is formed by extruding a liquid material containing a resin material from an opening provided in the die coater using a slot die method and supplying (coating) the liquid material on the metal foil. It is formed by coating a metal foil with a material to obtain a liquid film, and then drying the liquid film to form a coating layer (see, for example, Patent Document 1).

  However, in such a method using the slot die method, the dynamic contact point when the liquid material used for obtaining the coating layer is applied on the metal foil is three layers of gas phase / solid phase / liquid phase. It becomes an interface. Therefore, if the film thickness of the target coating layer becomes too thick, bubbles are generated in the coating layer due to entrainment of air in the gas phase during the formation of the liquid coating, and the film characteristics of the coating layer There was a problem that decreased.

  Such a problem occurs not only in the formation of the coating layer on the metal foil but also in the formation of a layer (covering layer) containing a resin material on various substrates.

JP 2001-49203 A

  An object of the present invention is to provide a coating apparatus and a coating method capable of forming a thick coating layer without causing bubbles in the resulting coating layer, and a coating formed using such a coating method. An object of the present invention is to provide a metal foil-clad substrate, a circuit board, an electronic component mounting board, and an electronic device, each having a layer and excellent in reliability.

Such an object is achieved by the present invention described in the following (1) to (12).
(1) A coating apparatus that forms a coating layer by coating a liquid coating layer forming material on one surface of the base sheet by a slot die method while transporting the base sheet in the transport direction. Because
Conveying means for conveying the substrate sheet along the conveying direction; and coating means for applying the coating layer forming material to one surface of the substrate sheet,
The coating means includes: a first die coater that coats the coating layer forming material on one surface of the base sheet to form a first liquid film; and the first die coater A second die coat disposed at a predetermined distance on the downstream side in the conveying direction, and applying the coating layer forming material to one surface of the first liquid coating to form a second liquid coating. A coating apparatus comprising: a coating device.

  (2) Drying to form the coating layer by drying the liquid film laminate formed by laminating the first liquid film and the second liquid film formed on one surface of the base sheet. The coating apparatus according to (1), wherein the means is provided on the downstream side in the transport direction with respect to the coating means.

  (3) The coating apparatus according to (1) or (2), wherein the first liquid coating is formed within a range of 3 μm or more and 150 μm or less.

  (4) The coating layer forming material used for forming the first liquid film has the viscosity set in the range of 3 cP or more and 1500 cP or less, according to any one of (1) to (3). Coating equipment.

  (5) The coating apparatus according to any one of (1) to (4), wherein the second liquid film is formed within a range of 50 μm to 500 μm.

  (6) The said coating layer forming material used for formation of said 2nd liquid film is described in any one of said (1) thru | or (5) by which the viscosity is set in the range of 100 cP or more and 500 cP or less. Coating equipment.

  (7) The coating apparatus according to any one of (1) to (6), wherein a conveyance speed for conveying the base sheet in the conveyance direction is set to 3 m / min or more and 16 m / min or less.

(8) A coating method of forming a coating layer by coating a liquid coating layer forming material on one surface of the substrate sheet by a slot die method while transporting the substrate sheet in the transport direction. Because
A first step of forming the first liquid film by applying the coating layer forming material to one surface of the base sheet while transporting the base sheet along the transport direction;
A second step of applying the coating layer forming material to one surface of the first liquid coating to form a second liquid coating;
A third step of obtaining the coating layer by drying a liquid film laminate formed by laminating the first liquid film and the second liquid film formed on one surface of the base sheet; The coating method characterized by having.

(9) In the coating method according to (8) above, the base sheet is a metal foil, and the coating layer contains a resin material,
A metal foil-clad substrate, wherein the coating layer formed by the coating method according to claim 8 is laminated on the metal foil.

(10) A circuit board formed using the metal foil-clad substrate according to (9) above,
A circuit board comprising a circuit provided with terminals for electrically connecting electronic components formed by patterning the metal foil.

  (11) An electronic component mounting board comprising: the circuit board according to (10) above; and the electronic component that is electrically connected to the terminal and mounted on the circuit board.

  (12) An electronic apparatus comprising the electronic component mounting board according to (11).

  By adopting the configuration of the coating apparatus and the coating method of the present invention, a thick coating layer can be formed without generating bubbles in the resulting coating layer.

  Therefore, by applying the coating method of the present invention to the formation of a coating layer containing a resin material included in a metal foil-clad substrate, even if the coating layer is thick, the coating layer It is possible to form a film without generating bubbles therein.

  Therefore, it is possible to provide a metal foil-clad substrate, a circuit board, an electronic component mounting substrate, and an electronic device having such a coating layer with excellent reliability.

It is a longitudinal cross-sectional view which shows embodiment which applied the electronic component mounting substrate of this invention to mounting of a semiconductor device. It is a figure for demonstrating the manufacturing method of the metal foil tension board | substrate used for manufacture of the electronic component mounting board | substrate of FIG. It is a figure for demonstrating the coating apparatus used for the manufacturing method of the metal foil tension board | substrate used for manufacture of the electronic component mounting board | substrate of FIG. It is the elements on larger scale which expanded the 1st head and tensioner with which the coating apparatus shown in FIG. 3 was partially expanded. It is the elements on larger scale which expanded the 2nd head and tensioner with which the coating apparatus shown in FIG. 3 was partially expanded. It is a graph which shows the relationship between the film thickness of a 1st liquid film, and a critical speed. It is a graph which shows the relationship between the viscosity of a 1st liquid film, and a critical speed.

  Hereinafter, a coating apparatus, a coating method, a metal foil-clad substrate, a circuit board, an electronic component mounting board, and an electronic device according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

  First, prior to describing the coating apparatus, coating method, metal foil-clad substrate, and circuit board of the present invention, the electronic component mounting substrate of the present invention will be described.

  Hereinafter, a case where the electronic component mounting substrate of the present invention is applied to mounting of a semiconductor device including a semiconductor element as an electronic component will be described as an example.

<Electronic component mounting board>
FIG. 1 is a longitudinal sectional view showing an embodiment in which an electronic component mounting board of the present invention is applied to mounting of a semiconductor device. In the following, for convenience of explanation, the upper side in FIG. 1 is also referred to as “upper” and the lower side in FIG. 1 is also referred to as “lower”. In each figure, the electronic component mounting board and its respective parts are schematically shown in an exaggerated manner, and the sizes and ratios of the electronic component mounting board and its respective parts are greatly different from actual ones.

  An electronic component mounting board 55 shown in FIG. 1 includes a semiconductor device 1 as an electronic component and a circuit board (circuit board of the present invention) 10 on which the semiconductor device 1 is mounted. In addition to the semiconductor device 1, other electronic components (members) such as resistors and transistors are usually mounted on the circuit board 10, but the description is omitted in FIG. 1 for convenience of explanation. Yes.

  The semiconductor device 1 is a semiconductor package including a semiconductor element (not shown). A mold part (sealing part) 11 for sealing the semiconductor element (semiconductor chip) and the semiconductor element (semiconductor chip) are electrically connected. And a connection terminal 12 connected thereto.

  The semiconductor element is not particularly limited. For example, the semiconductor element is composed of SiC (silicon carbide) or GaN (gallium nitride), and the semiconductor element generates noise when driven.

  Moreover, the mold part 11 is normally comprised with the hardened | cured material of various resin materials, and is sealing by surrounding a semiconductor element.

  Further, the connection terminal 12 is made of various metal materials such as Cu, Fe, Ni, and alloys thereof, and is connected to a terminal provided in the semiconductor element and a terminal provided in the wiring 4 included in the circuit board 10. Thereby, the terminal provided in the semiconductor element and the terminal provided in the wiring 4 are electrically connected.

  The circuit board 10 (wiring board) supports the wiring 4 electrically connected to the semiconductor device 1 and the wiring 4 provided on the lower surface (surface opposite to the semiconductor device 1; one surface) of the wiring 4. And a base material (base part) 8 having a flat plate shape (sheet shape).

  The wiring (circuit) 4 is formed in a predetermined pattern, and a terminal (not shown) provided by the formation of this pattern is electrically connected to a connection terminal (terminal) 12 included in the semiconductor device 1. Thereby, the terminal provided in the semiconductor element and the terminal provided in the wiring 4 are electrically connected.

  The wiring (conductor portion) 4 is for electrically connecting electronic components including the semiconductor device 1 mounted on the circuit board 10, and patterning the metal foil 4 </ b> A included in the metal foil-clad substrate 10 </ b> A described later. Formed with.

  Examples of the constituent material of the wiring 4 include various metal materials such as copper, a copper-based alloy, aluminum, and an aluminum-based alloy.

The wiring (conductor portion) 4 has a thickness (average thickness) t ₄ of preferably 3 μm or more and 120 μm or less, and more preferably 5 μm or more and 70 μm or less. By setting the thickness of the wiring 4 in such a numerical range, the conductivity that functions as the wiring 4 can be ensured without increasing the size of the circuit board 10.

  The substrate 8 includes a resin layer 5 having a flat plate shape (sheet shape) and an insulating portion 6 provided on the lower surface (one surface) of the resin layer 5 and covering the resin layer 5. The base material 8 has a function of supporting the semiconductor device 1 mounted on the wiring 4 and suppressing or preventing the propagation of noise generated by driving the semiconductor device 1 (semiconductor element).

  In the present embodiment, a base material layer containing a resin material is constituted by the base material 8, that is, a laminate of the resin layer 5 and the insulating portion 6.

  The resin layer (bonding layer) 5 is provided on the lower surface of the wiring 4, that is, provided between the wiring 4 and the insulating portion 6 located on the lower side of the wiring 4. And the insulating part 6 are joined. This resin layer 5 has insulating properties. Thereby, the insulation state of the wiring 4 and the other member (for example, another circuit board) located below this resin layer 5 is ensured. Further, the propagation of the noise to other members can be suppressed or prevented.

The thickness (average thickness) t ₅ of the resin layer 5 is not particularly limited, but as shown in FIG. 1, it is thinner than the thickness t ₆ of the insulating portion 6, specifically about 50 μm to 250 μm. It is preferable that the thickness is about 80 μm to 200 μm. Thereby, the insulating property of the resin layer 5 can be ensured without increasing the size of the base material 8. In addition, the propagation of noise generated by driving the semiconductor device 1 can be reliably suppressed or prevented.

  In addition, the resin layer 5 preferably has a high thermal conductivity, specifically 1 W / m · K or more and 15 W / m · K or less, preferably 5 W / m · K or more and 10 W / More preferably, it is m · K or less. Thereby, the heat on the semiconductor device 1 side is efficiently transferred to the insulating portion 6 side by the resin layer 5. Therefore, heat generated by driving the semiconductor element of the semiconductor device 1 can be efficiently transmitted to the insulating portion 6 via the wiring 4 and the resin layer 5, so that the heat generated in the semiconductor device 1 is on the insulating portion 6 side. It is possible to efficiently dissipate heat.

  Furthermore, the resin layer 5 preferably has a glass transition temperature of 100 ° C. or higher and 200 ° C. or lower. Thereby, since the rigidity of the resin layer 5 increases and the warp of the resin layer 5 can be reduced, the occurrence of warp in the circuit board 10 can be suppressed.

  In addition, the glass transition temperature of the resin layer 5 can be measured as follows based on JIS C 6481.

  Using a dynamic viscoelasticity measuring device (DMA Instruments' DMA / 983) under a nitrogen atmosphere (200 ml / min), a tensile load was applied, and a frequency of 1 Hz and a temperature of −50 ° C. to 300 ° C. The range is measured at a temperature rising rate of 5 ° C./min, and the glass transition temperature Tg is obtained from the peak position of tan δ.

  The elastic modulus (storage elastic modulus) E ′ at 25 ° C. of the resin layer 5 is preferably 10 GPa or more and 70 GPa or less. Thereby, since the rigidity of the resin layer 5 increases, the curvature produced in the resin layer 5 can be reduced. As a result, the occurrence of warpage in the circuit board 10 can be suppressed.

  The storage elastic modulus can be measured with a dynamic viscoelasticity measuring device. Specifically, the storage elastic modulus E ′ is obtained by applying a tensile load to the resin layer 5, a frequency of 1 Hz, and a heating rate of 5 It is measured as the value of the storage elastic modulus at 25 ° C. when measured from −50 ° C. to 300 ° C. at −10 ° C./min.

  The resin layer 5 having such a function has a configuration in which fillers are dispersed in a layer composed of a resin material as a main material.

  The resin material usually exhibits a function as a binder for holding the filler in the resin layer 5, and the filler has a thermal conductivity higher than that of the resin material. By making the resin layer 5 have such a configuration, the resin layer 5 can have excellent thermal conductivity.

  Such a resin layer 5 is comprised with the solidified material or hardened | cured material formed by solidifying or hardening the resin composition for resin layer formation containing a resin material and a filler mainly. That is, the resin layer 5 is composed of a cured product or a solidified product obtained by forming a resin composition for forming a resin layer into a layer shape.

Hereinafter, the resin composition for forming a resin layer will be described.
As described above, the resin composition for forming a resin layer mainly includes a resin material and a filler.

  The resin material is not particularly limited, and various resin materials such as a thermoplastic resin and a thermosetting resin can be used.

  Examples of the thermoplastic resin include polyolefins such as polyethylene, polypropylene, and ethylene-vinyl acetate copolymer, modified polyolefins, polyamides (eg, nylon 6, nylon 46, nylon 66, nylon 610, nylon 612, nylon 11, nylon 12). , Nylon 6-12, nylon 6-66), thermoplastic polyimide, aromatic polyester and other liquid crystal polymers, polyphenylene oxide, polyphenylene sulfide, polycarbonate, polymethyl methacrylate, polyether, polyether ether ketone, polyether imide, polyacetal, Styrene, polyolefin, polyvinyl chloride, polyurethane, polyester, polyamide, polybutadiene, trans polyisoprene, fluoro rubber, salt Various thermoplastic elastomers, etc., or a copolymer of these His polyethylene type or the like, blends, polymer alloys and the like, can be used as a mixture of two or more of them.

  On the other hand, examples of the thermosetting resin (second thermosetting resin) include an epoxy resin, a phenol resin, a urea resin, a melamine resin, a polyester (unsaturated polyester) resin, a polyimide resin, a silicone resin, and a polyurethane resin. 1 type or 2 types or more of these can be mixed and used.

  Among these, as a resin material used for the resin composition for forming a resin layer, it is preferable to use a thermosetting resin, and it is more preferable to use an epoxy resin. Thereby, the heat resistance of the resin layer 5 obtained can be made excellent. Further, the wiring 4 can be firmly bonded to the base material 8 by the resin layer 5. Therefore, it is possible to make the obtained electronic component mounting board 55 excellent in durability and heat dissipation.

  Moreover, it is preferable that an epoxy resin contains the epoxy resin (A) which has at least any one of an aromatic ring structure and an alicyclic structure (alicyclic carbocyclic structure). By using such an epoxy resin (A), the glass transition temperature can be increased. Moreover, the adhesiveness with respect to the wiring 4 and the insulating part 6 can be improved.

  Furthermore, as the epoxy resin (A) having an aromatic ring or alicyclic structure, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol E type epoxy resin, bisphenol M type epoxy resin, Bisphenol P type epoxy resin, bisphenol type epoxy resin such as bisphenol Z type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, novolak type epoxy resin such as tetraphenol group ethane type novolak type epoxy resin, biphenyl type epoxy resin , Arylalkylene type epoxy resins such as phenol aralkyl type epoxy resins having a biphenylene skeleton, and epoxy resins such as naphthalene type epoxy resins. May be used alone or in combination of two or more out.

  The epoxy resin (A) is preferably a naphthalene type epoxy resin. Thereby, a glass transition temperature can be made still higher, generation | occurrence | production of the void of the resin layer 5 can be suppressed, and a dielectric breakdown voltage can be improved. In addition, the resin layer 5 can suppress noise propagation.

  The naphthalene type epoxy resin is one having a naphthalene ring skeleton and having two or more glycidyl groups.

  The content of the naphthalene type epoxy resin in the epoxy resin is preferably 20% by mass or more and 80% by mass or less, and more preferably 40% by mass or more and 60% by mass or less, with respect to 100% by mass of the epoxy resin.

  Examples of the naphthalene type epoxy resin include any of the following formulas (5) to (8).

［式中、ｍ、ｎはナフタレン環上の置換基の個数を示し、それぞれ独立して１〜７の整数を示す。］

[Wherein, m and n represent the number of substituents on the naphthalene ring, and each independently represents an integer of 1 to 7. ]

  In addition, as a compound of Formula (6), it is preferable to use any 1 or more types of the following.

［式中、Ｍｅはメチル基を示し、ｌ、ｍ、ｎは１以上の整数を示す。］

[Wherein, Me represents a methyl group, and l, m, and n represent an integer of 1 or more. ]

［式中、ｎは１以上２０以下の整数であり、ｌは１以上２以下の整数であり、Ｒ_１はそれぞれ独立に水素原子、ベンジル基、アルキル基または下記式（９）で表される構造であり、Ｒ_２はそれぞれ独立に水素原子またはメチル基である。］

[Wherein, n is an integer of 1 or more and 20 or less, l is an integer of 1 or more and 2 or less, and each R ₁ is independently represented by a hydrogen atom, a benzyl group, an alkyl group or the following formula (9). And R ₂ is independently a hydrogen atom or a methyl group. ]

［式中、Ａｒはそれぞれ独立にフェニレン基またはナフチレン基であり、Ｒ_２はそれぞれ独立に水素原子またはメチル基であり、ｍは１または２の整数である。］

[Wherein, Ar is each independently a phenylene group or a naphthylene group, R ₂ is each independently a hydrogen atom or a methyl group, and m is an integer of 1 or 2. ]

  The naphthalene type epoxy resin of the formula (8) is classified as a so-called naphthylene ether type epoxy resin, and the compound represented by the formula (8) is exemplified by those represented by the following formula (10). It is done.

［上記式（１０）において、ｎは１以上２０以下の整数であり、好ましくは１以上１０以下の整数であり、より好ましくは１以上３以下の整数である。Ｒはそれぞれ独立に水素原子または下記式（１１）で表される構造であり、好ましくは水素原子である。］

[In the above formula (10), n is an integer of 1 or more and 20 or less, preferably an integer of 1 or more and 10 or less, more preferably an integer of 1 or more and 3 or less. Each R is independently a hydrogen atom or a structure represented by the following formula (11), preferably a hydrogen atom. ]

［上記式（１１）において、ｍは１または２の整数である。］

[In the above formula (11), m is an integer of 1 or 2. ]

  Furthermore, specific examples of the naphthylene ether type epoxy resin represented by the above formula (10) include those represented by the following formulas (12) to (16).

  The content of the resin material is preferably 30% by volume or more and 70% by volume or less, and preferably 40% by volume or more and 60% by volume or less of the entire resin composition for resin layer formation (excluding the solvent). Is more preferable. Thereby, the mechanical strength of the resin layer 5 obtained can be made excellent. Moreover, the adhesiveness with respect to the wiring 4 and the insulating part 6 can be improved.

  On the other hand, when the content is less than the lower limit value, depending on the type of the resin material, the resin material cannot sufficiently function as a binder for bonding fillers to each other, and the resulting resin layer 5 is obtained. There is a risk that the mechanical strength of the steel will decrease. Moreover, depending on the constituent material of the resin composition for forming a resin layer, the viscosity of the resin composition for forming a resin layer becomes too high, and the filtering operation or layered molding (coating) of the resin composition for forming a resin layer (varnish) may occur. It becomes difficult or the flow of the resin composition for forming a resin layer becomes too small, and there is a possibility that voids are generated in the resin layer 5.

  On the other hand, when the content exceeds the upper limit, depending on the type of the resin material, it may be difficult to make the resin layer 5 excellent in insulation.

  Moreover, when a resin material contains an epoxy resin, it is preferable that the resin composition for resin layer formation contains the phenoxy resin. Thereby, since the bending resistance of the resin layer 5 can be improved, the handleability fall of the resin layer 5 by highly filling a filler can be suppressed.

  In addition, when the phenoxy resin is included, the fluidity at the time of pressing is reduced due to the increase in viscosity, and the thickness of the resin layer 5 is ensured, and the thickness uniformity and void suppression are effective. it can. Further, the adhesion between the resin layer 5 and the wiring 4 and the insulating portion 6 is improved. By these synergistic effects, the insulation reliability of the electronic component mounting board 55 can be further enhanced. In addition, the noise propagation property in the electronic component mounting board 55 can be accurately suppressed or prevented.

  Examples of the phenoxy resin include a phenoxy resin having a bisphenol skeleton, a phenoxy resin having a naphthalene skeleton, a phenoxy resin having an anthracene skeleton, and a phenoxy resin having a biphenyl skeleton. A phenoxy resin having a structure having a plurality of these skeletons can also be used.

  Among these, it is preferable to use bisphenol A type or bisphenol F type phenoxy resin. A phenoxy resin having both a bisphenol A skeleton and a bisphenol F skeleton may be used.

The weight average molecular weight of the phenoxy resin is not particularly limited, but is preferably 4.0 × 10 ⁴ or more and 8.0 × 10 ⁴ or less.

  In addition, the weight average molecular weight of a phenoxy resin is a value in terms of polystyrene measured by gel permeation chromatography (GPC).

  The content of the phenoxy resin is preferably 1% by mass to 15% by mass, and more preferably 2% by mass to 10% by mass with respect to 100% by mass of the total solid content of the resin composition for forming a resin layer, for example. .

  In addition, the resin composition for forming a resin layer includes a curing agent as necessary depending on the type of the resin material described above (for example, in the case of an epoxy resin).

  The curing agent is not particularly limited, and examples thereof include amide curing agents such as dicyandiamide and aliphatic polyamide, amine curing agents such as diaminodiphenylmethane, methanephenylenediamine, ammonia, triethylamine, and diethylamine, bisphenol A, and bisphenol F. And phenolic curing agents such as phenol novolac resin, cresol novolak resin, p-xylene-novolak resin, and acid anhydrides.

  Moreover, the resin composition for forming a resin layer may further contain a curing catalyst (curing accelerator). Thereby, the sclerosis | hardenability of the resin composition for resin layer formation can be improved.

  Examples of the curing catalyst include amine catalysts such as imidazoles, 1,8-diazabicyclo (5,4,0) undecene, phosphorus catalysts such as triphenylphosphine, and the like. Of these, imidazoles are preferred. Thereby, especially the quick-hardening property and the preservability of the resin composition for resin layer formation can be made compatible.

  Examples of imidazoles include 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, 1-cyanoethyl-2- Phenylimidazolium trimellitate, 2,4-diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine, 2,4-diamino-6- [2'-undecylimidazolyl- (1 ′)]-Ethyl-s-triazine, 2,4-diamino-6- [2′-ethyl-4′methylimidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino-6 -[2'-Methylimidazolyl- (1 ')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole Null acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,4-diamino-6-vinyl-s-triazine, 2,4-diamino -6-vinyl-s-triazine isocyanuric acid adduct, 2,4-diamino-6-methacryloyloxyethyl-s-triazine, 2,4-diamino-6-methacryloyloxyethyl-s-triazine isocyanuric acid adduct, etc. Can be mentioned. Among these, 2-phenyl-4,5-dihydroxymethylimidazole or 2-phenyl-4-methyl-5-hydroxymethylimidazole is preferable. Thereby, especially the preservability of the resin composition for resin layer formation can be improved.

  Moreover, the content of the curing catalyst is not particularly limited, but is preferably about 0.01 to 30 parts by mass, more preferably about 0.5 to 10 parts by mass with respect to 100 parts by mass of the resin material. preferable. When the content is less than the lower limit, the curability of the resin composition for forming a resin layer may be insufficient. On the other hand, when the content exceeds the upper limit, the resin composition for forming a resin layer. It shows a tendency to decrease the storage stability of the object.

  The average particle diameter of the curing catalyst is not particularly limited, but is preferably 10 μm or less, and more preferably 1 to 5 μm. When the average particle size is within the above range, the reactivity of the curing catalyst is particularly excellent.

  Moreover, it is preferable that the resin composition for resin layer formation contains a coupling agent further. Thereby, the adhesiveness of the resin material with respect to a filler, the insulation part 6, and the wiring 4 can be improved more.

  Examples of such coupling agents include silane coupling agents, titanium coupling agents, aluminum coupling agents, and the like. Of these, silane coupling agents are preferred. Thereby, the heat resistance of the resin composition for resin layer formation can be improved more.

  Among these, as the silane coupling agent, for example, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, N-β (aminoethyl) γ-aminopropylmethyl Dimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysila N-phenyl-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, bis (3 -Triethoxysilylpropyl) tetrasulfane and the like.

  Although content of a coupling agent is not specifically limited, It is preferable that it is about 0.01-10 mass parts with respect to 100 mass parts of resin materials, and it is more preferable that it is especially about 0.5-10 mass parts. . When the content is less than the lower limit, the effect of improving the adhesion as described above may be insufficient. On the other hand, when the content exceeds the upper limit, the resin layer 5 is formed. May cause outgassing and voids.

  Moreover, the filler in the resin composition for resin layer formation is comprised with an inorganic material. Thereby, a filler exhibits heat conductivity higher than the heat conductivity of a resin material. Therefore, the thermal conductivity of the resin layer 5 can be increased by dispersing the filler in the resin composition for forming a resin layer.

Such a filler is preferably a granular body composed of at least one of aluminum oxide (alumina, Al ₂ O ₃ ) and aluminum nitride among those composed of inorganic materials, and is mainly mainly oxidized. A granular body made of aluminum is preferable. Thereby, it can be set as the filler excellent in heat conductivity (heat dissipation) and insulation. Aluminum oxide is particularly preferably used because it is highly versatile and can be obtained at low cost.

  Therefore, hereinafter, a case where the filler is a granular body mainly composed of aluminum oxide will be described as an example.

  The content of the filler is preferably 30% by volume or more and 70% by volume or less, and more preferably 40% by volume or more and 60% by volume or less of the entire resin composition for forming a resin layer (excluding the solvent). By making the content rate of the filler in the resin composition for resin layer formation high like this range, the thermal conductivity of the resin layer 5 can be made more excellent.

  On the other hand, when the content is less than the lower limit value, it is difficult to ensure the heat conductivity of the resin layer 5 while ensuring the insulation of the resin layer 5. On the other hand, when the content exceeds the upper limit, depending on the constituent material of the resin composition for resin layer formation, the viscosity of the resin composition for resin layer formation becomes too high, and the varnish is filtered or formed into a layer. (Coating) may become difficult, or the flow of the resin composition for forming a resin layer may become too small, and voids may be generated in the resulting resin layer 5.

  Even if the filler content in the resin composition for forming a resin layer is set high as in the above range, the resin composition for forming a resin layer has a temperature of 25 ° C. and a shear rate of 1.0 rpm. 2. A / B (thixo ratio) is 1.2 or more when the viscosity is A [Pa · s], the viscosity at a temperature of 25 ° C. and a shear rate of 10.0 rpm is B [Pa · s]. By using a material that satisfies a relationship of 0 or less, the viscosity and flowability of the resin composition for forming a resin layer (varnish) can be made appropriate during the production of the circuit board 10 (metal foil-clad substrate 10A). it can.

  The water content of the filler is preferably 0.10% by mass to 0.30% by mass, more preferably 0.10% by mass to 0.25% by mass, and 0.12% by mass. % Or more and 0.20% by mass or less is more preferable. Thereby, even if the content of the filler is increased, it has a more appropriate viscosity and flowability. Therefore, the resin layer 5 excellent in thermal conductivity can be formed while preventing generation of voids in the obtained resin layer 5. That is, the resin layer 5 having excellent thermal conductivity and insulation can be formed.

  Aluminum oxide is usually obtained by firing aluminum hydroxide. The obtained aluminum oxide granules are composed of a plurality of primary particles, and the average particle size of the primary particles can be set according to the firing conditions.

  Moreover, the aluminum oxide which has not been treated at all after the firing is composed of aggregates (secondary particles) in which primary particles are aggregated due to fixation.

  Therefore, the final filler can be obtained by solving the aggregation of the primary particles as necessary by pulverization. The average particle diameter of the final filler can be set according to the pulverization conditions (for example, time).

  During the pulverization, the aluminum oxide has a very high hardness, so the primary particles themselves are hardly broken, and the average particle size of the primary particles is almost maintained even after pulverization. The Rukoto.

  Therefore, as the grinding time becomes longer, the average particle size of the filler approaches the average particle size of the primary particles. And when grinding | pulverization time becomes more than predetermined time, the average particle diameter of a filler will become equal to the average particle diameter of a primary particle. That is, the filler is mainly composed of secondary particles when the grinding time is shortened, and the content of primary particles increases as the grinding time is lengthened. It will be.

  Further, for example, primary particles of aluminum oxide obtained by firing aluminum hydroxide as described above have a shape having a flat surface such as a scaly shape instead of a spherical shape. Therefore, the contact area between fillers can be increased. As a result, the thermal conductivity of the obtained resin layer 5 can be increased.

  Furthermore, the filler is a mixed system of three components (large particle size, medium particle size, and small particle size) having different average particle sizes, and the large particle size component is spherical, and the medium particle size component and small particle size are The component is preferably polyhedral.

  More specifically, the filler belongs to the first particle size range in which the average particle diameter is 5.0 μm or more and 50 μm or less, preferably 5.0 μm or more and 25 μm or less, and the circularity is 0.80 or more and 1.0 or less. And preferably having a large particle size of alumina of 0.85 or more and 0.95 or less and a second particle size range in which the average particle size is 1.0 μm or more and less than 5.0 μm, and the circularity is 0.50 or more and 0 .90 or less, preferably 0.70 or more and 0.80 or less, medium particle size aluminum oxide, an average particle size belonging to a third particle size range of 0.1 μm or more and less than 1.0 μm, and circularity of 0 It is preferably a mixture with small particle size aluminum oxide having a particle size of .50 to 0.90, preferably 0.70 to 0.80.

  The particle size of the filler can be measured by dispersing aluminum oxide in water for 1 minute using a laser diffraction particle size distribution analyzer SALD-7000.

  As a result, the medium particle size component is filled in the gap between the large particle size components, and the small particle size component is filled in the gap between the medium particle size components. The contact area can be increased. As a result, the thermal conductivity of the resin layer 5 can be further improved. Furthermore, the heat resistance, bending resistance, and insulation of the resin layer 5 can be further improved.

  Further, by using such a filler, the adhesion between the resin layer 5 and the wiring 4 and the insulating portion 6 can be further improved.

  By these synergistic effects, the insulation reliability and heat radiation reliability of the electronic component mounting board 55 can be further enhanced.

  In addition, the resin composition for forming a resin layer may contain additives such as a leveling agent and an antifoaming agent in addition to the components described above.

  Moreover, the resin composition for resin layer formation contains solvents, such as methyl ethyl ketone, acetone, toluene, a dimethylformaldehyde, for example. Thereby, the resin composition for resin layer formation will be in a varnish state, when resin material etc. melt | dissolve in a solvent.

  Such a resin composition for forming a resin layer having a varnish shape can be obtained, for example, by mixing a resin material and a solvent as necessary to make a varnish shape, and further mixing a filler. it can.

  The mixer used for mixing is not particularly limited, and examples thereof include a disperser, a composite blade type stirrer, a bead mill, and a homogenizer.

  In addition, when it is not necessary to provide the resin layer 5 with excellent thermal conductivity, aluminum hydroxide, magnesium hydroxide, silicon dioxide (silica), silicon carbide is used as a filler contained in the resin composition for resin layer formation. Those having a low thermal conductivity such as barium sulfate and barium titanate can be used. Furthermore, you may make it abbreviate | omit the addition of the filler to the resin composition for resin layer formation. That is, the resin layer 5 can be mainly composed of a resin material in which addition of a filler is omitted.

The insulating part 6 is formed so as to cover the lower surface of the resin layer 5.
Thereby, while ensuring the insulation on the lower surface side of the base material 8, the strength of the base material 8 as a whole is ensured. Further, it is possible to suppress or prevent the noise generated by driving the semiconductor device 1 (semiconductor element) from propagating to other members located below the insulating portion 6.

The insulating part 6 has a thickness (average thickness) _{t 6} is, for example, 1 mm or more, preferably 3mm or less, 1.5 mm or more, and more preferably not more than 2.5 mm. By setting the thickness of the insulating portion 6 in such a numerical range, the function as the insulating portion 6 can be reliably exhibited without causing the circuit board 10 to be enlarged.

  This insulating part 6 is comprised with the hardened | cured material of the resin composition for insulating part formation mainly containing a thermosetting resin (1st thermosetting resin).

  By configuring the insulating part 6 with such a cured product, the difference in the coefficient of thermal expansion between the resin layer 5 and the insulating part 6 can be set small. Accordingly, when the semiconductor element of the semiconductor device 1 is driven, the semiconductor device 1 itself generates heat, and the resin layer 5 and the insulating portion 6 are heated. However, the warp between the resin layer 5 and the insulating portion 6 occurs. It is possible to accurately suppress or prevent the occurrence of peeling due to this.

Hereinafter, this insulating part forming resin composition will be described.
The thermosetting resin (first thermosetting resin) is not particularly limited. For example, a phenol resin, an epoxy resin, a urea (urea) resin, a resin having a triazine ring such as a melamine resin, an unsaturated polyester resin, A bismaleimide (BMI) resin, a polyurethane resin, a diallyl phthalate resin, a silicone resin, a resin having a benzoxazine ring, a cyanate ester resin, and the like can be given, and one or more of these can be used in combination. Among them, since the phenol resin has good fluidity, the fluidity of the resin composition for forming an insulating part can be improved, and the insulating part 6 having a uniform thickness is formed so as to cover the resin layer 5. It is preferably used because it can be used. Moreover, the adhesiveness with respect to the resin layer 5 can be improved.

  Examples of the phenol resin include unmodified phenol novolak resin, cresol novolak resin, bisphenol A novolak resin, novolak type phenol resin such as arylalkylene type novolak resin, dimethylene ether type resole resin, methylol type resole resin and the like. And resole phenolic resins such as oil-modified resole phenolic resins modified with tung oil, linseed oil, walnut oil and the like.

  Moreover, when using a novolak-type phenol resin, although the hardening | curing agent is contained in the resin composition for insulation part formation, hexamethylenetetramine is normally used as this hardening | curing agent. Further, when hexamethylenetetramine is used, its content is not particularly limited, but it is preferably 10 to 30 parts by weight, more preferably 15 to 20 parts by weight with respect to 100 parts by weight of the novolak type phenol resin. It is preferable to contain it by weight part or less. By setting the content of hexamethylenetetramine in the above range, the cured product of the resin composition for forming an insulating part, that is, the mechanical strength and the amount of molding shrinkage of the insulating part 6 can be improved.

  Among such phenol resins, it is preferable to use a resol type phenol resin. When a novolac type phenol resin is used as a main component, as described above, hexamethylenetetramine is usually used as a curing agent, and corrosive gas such as ammonia gas is generated when the novolac type phenol resin is cured. For this reason, the wiring 4 and the like may corrode due to this, and therefore, a resol type phenol resin is preferably used as compared with a novolac type phenol resin.

  Moreover, a resol type phenol resin and a novolac type phenol resin can be used in combination. Thereby, while being able to raise the intensity | strength of the insulation part 6, toughness can also be improved.

  Examples of the epoxy resin include bisphenol type epoxy resins such as bisphenol A type, bisphenol F type and bisphenol AD type, novolac type epoxy resins such as phenol novolak type and cresol novolak type, brominated bisphenol A type, bromine Brominated epoxy resin such as a fluorinated phenol novolak type, biphenyl type epoxy resin, naphthalene type epoxy resin, tris (hydroxyphenyl) methane type epoxy resin and the like. Among these, bisphenol A type epoxy resins, phenol novolac type epoxy resins, and cresol novolac type epoxy resins having a relatively low molecular weight are preferable. Thereby, workability | operativity at the time of formation of the insulation part 6 and a moldability can be made further favorable. Further, from the viewpoint of heat resistance of the insulating portion 6, a phenol novolac type epoxy resin, a cresol novolac type epoxy resin, and a tris (hydroxyphenyl) methane type epoxy resin are preferable, and a tris (hydroxyphenyl) methane type epoxy resin is particularly preferable.

  When using a tris (hydroxyphenyl) methane type epoxy resin, the number average molecular weight is not particularly limited, but is preferably 500 to 2000, and more preferably 700 to 1400.

  Moreover, when using an epoxy resin, it is preferable that a hardening | curing agent is contained in the resin composition for insulation part formation. The curing agent is not particularly limited, and examples thereof include amine compounds such as aliphatic polyamines, aromatic polyamines and diciamine diamide, alicyclic acid anhydrides, acid anhydrides such as aromatic acid anhydrides, and novolak phenols. Examples thereof include polyphenol compounds such as resins, imidazole compounds, and the like. Among these, novolac type phenol resins are preferable. This improves the handling and workability of the insulating portion forming resin composition, and makes the insulating portion forming resin composition excellent in environmental aspects.

  In particular, when a phenol novolac type epoxy resin, a cresol novolac type epoxy resin, or a tris (hydroxyphenyl) methane type epoxy resin is used as the epoxy resin, it is preferable to use a novolac type phenol resin as the curing agent. Thereby, the heat resistance of the hardened | cured material obtained from the resin composition for insulating part formation can be improved. In addition, the addition amount of the curing agent is not particularly limited, but it is preferable that the curing width is within ± 10% by weight from the theoretical equivalent ratio of 1.0 to the epoxy resin.

  Moreover, the resin composition for insulating part formation may contain a hardening accelerator with the said hardening | curing agent as needed. Although it does not specifically limit as a hardening accelerator, For example, an imidazole compound, a tertiary amine compound, an organic phosphorus compound, etc. are mentioned. Although content of a hardening accelerator is not specifically limited, It is preferable that it is 0.1-10 weight part with respect to 100 weight part of epoxy resins, and it is more preferable that it is 3-8 weight part.

  Moreover, it is preferable that the resin composition for insulating part formation contains the fiber reinforcement which functions as a filler. Thereby, the mechanical strength and rigidity of the insulating part 6 itself can be made excellent.

  The fiber reinforcing material is not particularly limited. For example, glass fiber, carbon fiber, aramid fiber (aromatic polyamide), poly-p-phenylenebenzobisoxazole (PBO) fiber, polyvinyl alcohol (PVA) fiber, polyethylene (PE ) Fibers, plastic fibers such as polyimide fibers, inorganic fibers such as basalt fibers, and metal fibers such as stainless steel fibers. One or more of these can be used in combination.

  Further, these fiber reinforcements may be subjected to a surface treatment with a silane coupling agent for the purpose of improving the adhesion with the thermosetting resin. Although it does not specifically limit as a silane coupling agent, For example, an aminosilane coupling agent, an epoxy silane coupling agent, a vinyl silane coupling agent etc. are mentioned, It is used combining these 1 type (s) or 2 or more types. it can.

  Of these fiber reinforcements, it is preferable to use carbon fibers or aramid fibers. Thereby, the mechanical strength of the insulating part 6 can further be improved. In particular, the use of carbon fibers can further improve the wear resistance at high loads. In addition, from the viewpoint of further reducing the weight of the insulating portion 6, a plastic fiber such as an aramid fiber is preferable. Furthermore, from the viewpoint of improving the mechanical strength of the insulating portion 6, it is preferable to use a fiber base material such as glass fiber or carbon fiber as the fiber reinforcing material.

  The content of the fiber reinforcement in the cured product is, for example, 10% by volume or more, preferably 20% by volume or more, and more preferably 25% by volume or more with respect to the total amount of the cured product. Moreover, the upper limit of content of the fiber reinforcement with respect to hardened | cured material whole quantity is although it does not specifically limit, Preferably it is 80 volume% or less. Thereby, the mechanical strength of the insulation part 6 can be improved reliably.

  Further, the insulating portion forming resin composition may contain a filler other than the fiber reinforcement, and the filler may be either an inorganic filler or an organic filler.

  As the inorganic filler, for example, one or more selected from titanium oxide, zirconium oxide, silica, calcium carbonate, boron carbide, clay, mica, talc, wollastonite, glass beads, milled carbon, graphite and the like are used. . The inorganic filler preferably contains a metal oxide such as titanium oxide, zirconium oxide, or silica. Thereby, the oxide film with which a metal oxide is provided exhibits the function as a passivating film | membrane, and can improve the acid resistance as the whole hardened | cured material.

  As the organic filler, one or more selected from polyvinyl butyral, acrylonitrile butadiene rubber (NBR), pulp, wood powder, and the like are used. The acrylonitrile butadiene rubber may be either partially crosslinked or carboxy modified type. Of these, acrylonitrile butadiene rubber is preferred from the viewpoint of further enhancing the effect of improving the toughness of the cured product.

  Furthermore, it is preferable that a flame retardant is contained in the resin composition for forming an insulating part. Thereby, the flame retardance of the insulating part 6 can be improved.

  Further, the flame retardant is not particularly limited, but is particularly preferably a red phosphorus flame retardant. Thereby, the said effect can be exhibited more notably.

  Examples of the red phosphorus flame retardant include (1) red phosphorus coated with a thermosetting resin, and (2) red phosphorus coated with an inorganic material.

  In general, when a red phosphorus flame retardant is used as a flame retardant, there is a general concern that an insulation failure may occur due to a migration phenomenon occurring in the wiring. However, in the circuit board 10, the resin layer 5 is interposed between the wiring 4 and the insulating portion 6 even if the red phosphorus flame retardant is contained in the insulating portion forming resin composition. The occurrence of insulation failure can be accurately suppressed or prevented.

  In addition to the components described above, additives such as a mold release agent, a curing aid, and a pigment may be added to the insulating portion forming resin composition.

  Moreover, it is preferable that the filler contained in the resin layer 5 is dispersed on the insulating part 6 side at the interface between the insulating part 6 and the resin layer 5. Thereby, it can be said that the state where the resin layer 5 and the insulating portion 6 are mixed is formed at the interface between the resin layer 5 and the insulating portion 6, and the adhesion between the resin layer 5 and the insulating portion 6 is improved. It is done. Therefore, the durability of the electronic component mounting board 55 can be made excellent.

  The electronic component mounting board 55 shown in FIG. 1 on which the semiconductor device 1 is mounted as an electronic component as described above can be obtained by mounting the semiconductor device 1 on the circuit board 10. Instead of the wiring 4, a metal foil 4 </ b> A having a flat plate shape (sheet shape) can be obtained using a metal foil-clad substrate 10 </ b> A provided on the upper surface (the other surface) of the base material 8.

  The metal foil-clad substrate 10A is manufactured by a method for manufacturing the metal foil-clad substrate 10A as described below.

(Manufacturing method of metal foil-clad substrate)
FIG. 2 is a diagram for explaining a method of manufacturing a metal foil-clad substrate used for manufacturing the electronic component mounting substrate of FIG. In the following, for convenience of explanation, the upper side in FIG. 2 is also referred to as “upper” and the lower side is also referred to as “lower”. In addition, the metal foil-clad substrate and each part thereof are schematically illustrated in an exaggerated manner, and the size and the ratio of the metal foil-clad substrate and each part thereof are greatly different from actual ones.

[1]
First, a metal foil 4A is prepared, and then a resin layer forming layer 5A is formed on the metal foil 4A as shown in FIG.

  And this resin layer formation layer 5A turns into the resin layer 5 by hardening or solidifying through process [2] mentioned later.

  The resin layer forming layer 5A is not particularly limited. For example, after the resin layer forming resin composition (liquid material) that forms a liquid is supplied onto the metal foil 4A to form a layer (liquid coating), It can be obtained by drying, and a coating method (coating method of the present invention) using the coating apparatus of the present invention for supplying (coating) the resin composition for forming a resin layer onto the metal foil 4A. However, these will be described in detail later.

[2]
Next, the insulating portion 6 is formed on the resin layer forming layer 5A.
Further, at this time, if the resin layer forming layer 5A exhibits thermosetting properties, the resin layer forming layer 5A is cured to form the resin layer 5, and the resin layer forming layer 5A is thermoplastic. In this case, the resin layer 5 is formed by solidifying again after melting (see FIG. 2B).

  A method for forming the insulating portion 6 is not particularly limited. For example, the insulating portion forming resin composition that is in a liquid state is supplied onto the resin layer forming layer 5A to form a layer, and then dried. The method of obtaining is mentioned. In the same manner as the supply of the resin composition for forming a resin layer onto the metal foil 4A, the coating apparatus of the present invention is applied to the supply (application) of the resin composition for forming an insulating portion onto the resin layer formation layer 5A. The used coating method (the coating method of the present invention) can be applied.

  As described above, the metal foil-clad substrate 10A including the metal foil 4A and the base material 8 is produced. In the production of the metal foil-clad substrate 10A, the resin layer forming layer 5A and / or the insulating portion 6 are formed. The coating apparatus and the coating method of the present invention are applied to the formation. Hereinafter, the coating apparatus and the coating method will be sequentially described.

  In the following, when the coating apparatus and the coating method of the present invention are applied to the formation of the resin layer forming layer 5A (coating layer) on the metal foil 4A (base material sheet), that is, the metal foil 4A. A case where the present invention is applied to formation of a laminated body 7A including the resin layer forming layer 5A will be described as an example.

(Coating equipment)
FIG. 3 is a view for explaining a coating apparatus used in the method for manufacturing a metal foil-clad substrate used for manufacturing the electronic component mounting board of FIG. 1, and FIG. 4 is provided in the coating apparatus shown in FIG. FIG. 5 is a partially enlarged longitudinal sectional view in which the first head and the tensioner are partially enlarged, and FIG. 5 is a partially enlarged longitudinal sectional view in which the second head and the tensioner provided in the coating apparatus shown in FIG. 3 are partially enlarged. It is. In the following, for convenience of explanation, the upper side in FIGS. 3 to 5 is referred to as “upper” or “upper”, the lower side is referred to as “lower” or “lower”, the left side is referred to as “left”, and the right side is referred to as “right”. "

  The coating apparatus 100 is a resin composition for forming a resin layer (coating) which forms a liquid on the upper surface (one surface) of the metal foil 4A by the stot die method while conveying the metal foil 4A (base material sheet) in the conveying direction. A layer forming material) is applied to form a resin layer forming layer 5A (coating layer), and a liquid is formed on the metal foil 4A and a conveying means 40 for conveying the metal foil 4A along the conveying direction. A coating means 50 for applying (applying) a resin composition for forming a resin layer, and a resin layer forming resin composition which is located downstream from the coating means 50 and which is in a liquid state is dried to form a resin layer A drying means 60 for forming the forming layer 5A.

  As shown in FIG. 3, the conveying means 40 conveys the metal foil 4 </ b> A wound around the unwinding roller 46 along the longitudinal direction (left side to right side) that is the conveying direction, and the obtained laminated body 7 </ b> A. Is wound around the winding roller 48.

  The conveying means 40 is disposed between the unwinding roller 46 for winding the metal foil 4A, the winding roller 48 for winding (winding) the laminated body 7A, and the unwinding roller 46 and the winding roller 48. Tensioners (tension rollers) 41, 42, 43, 44.

  Each roller is made of a metal material such as stainless steel, for example. In addition, these rollers are disposed such that the rotation axes (center axes) face the same direction and are separated from each other. Furthermore, each roller is rotatably supported by a frame (not shown) that supports the entire coating apparatus 100, for example.

  The unwinding roller 46 has a cylindrical outer shape, is located on the most upstream side (leftmost side) in the transport direction of the metal foil 4A, and the metal foil 4A is wound in a roll shape. It is a roller that feeds in the transport direction.

  Each of the tensioners 41 to 44 is a roller that rotates while being wound around the outer shape of the metal foil 4A in contact with the middle of the metal foil 4A in the longitudinal direction. Thereby, it can convey, changing a conveyance direction, applying tension | tensile_strength to 4A of metal foils. In addition, in the middle of conveyance in these tensioners 41 to 44, a laminated body 7A in which the resin layer forming layer 5A is formed on the metal foil 4A is obtained.

  Further, the take-up roller 48 is a roller that takes up the laminated body 7A that is formed in a cylindrical shape and is positioned on the most downstream side in the transport direction of the metal foil 4A and is sent out from the upstream side in the transport direction. A motor (not shown) is connected to the winding roller 48, and the metal foil 4A is conveyed by the operation of the motor. Moreover, the conveyance speed of 4 A of metal foils can be changed by changing the magnitude | size of the voltage applied to a motor.

  The coating means 50 is for applying (supplying) a liquid resin layer forming resin composition (liquid material) onto the metal foil 4A by using a slot die method, as shown in FIGS. Thus, the two heads (die coater) 52, 53 for coating the resin composition for forming a resin layer on the metal foil 4A, that is, the first head (die coater) 52 and the second head (die coater) ) 53.

  Among these heads 52, 53, the first head 52 is opposed to the tensioner 42 located on the upstream side (left side) of the tensioner 43, with the metal foil 4 </ b> A interposed therebetween, and the upper side thereof. And is supported and fixed to the frame that supports the coating apparatus 100 as a whole. From the first head 52, a liquid resin layer forming resin composition is applied (supplied) to the upper surface (one surface) of the metal foil 4A. The liquid coating 31A is formed.

  Further, the second head 53 is opposed to the tensioner 43 located on the downstream side (right side) of the tensioner 42, that is, separated from the first head 52 by a predetermined distance downstream. The metal foil 4 </ b> A is disposed on the upper side of the tensioner 43, and is supported and fixed to the frame that supports the entire coating apparatus 100. From the second head 53, a liquid resin layer-forming resin composition is applied (supplied) to the upper surface of the first liquid coating 31A formed on the metal foil 4A. A second liquid film 31B is formed on one liquid film 31A. As a result, a liquid film laminate 31 in which the first liquid film 31A and the second liquid film 31B are laminated in this order is formed on the metal foil 4A.

  The heads 52 and 53 are extruded by a slot die method in a state where a liquid resin layer forming resin composition is formed into a belt-like coating film. Each of the heads 52 and 53 is supplied with a liquid resin layer forming resin composition from a tank (not shown), and the resin layer forming resin composition is provided in the openings of the heads 52 and 53. The resin composition for forming a resin layer, which is formed into a belt-like coating film, is continuously fed out by extruding from. And the 1st liquid film 31A and the 2nd liquid film 31B are formed because the coating film which makes these strip | belt shape coat | covers metal foil 4A continuously along a conveyance direction.

  In addition, as the resin composition for forming a resin layer that forms a liquid, for example, the constituent material of the resin layer forming layer 5A described above is dissolved or dispersed in a solvent or a dispersion medium, or the resin layer forming layer 5A is configured. A material that has been melted or softened by heating the material can be used. The solvent or dispersion medium is not particularly limited, and examples thereof include hydrocarbons such as mesitylene, decalin, mineral spirit, toluene, xylenes, anisole, propylene glycol monomethyl ether, dipropylene glycol methyl ether, diethylene glycol monoethyl ether. , Alcohol / ethers such as diglyme, ethylene carbonate, ethyl acetate, N-butyl acetate, ethyl lactate, ethyl 3-ethoxypropionate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene carbonate, γ-butyrolactone, etc. Esters / lactones, ketones such as cyclopentanone, cyclohexanone, methyl isobutyl ketone, 2-heptanone, N-methyl-2-pyrrolidone Amide / lactam may be mentioned of, can be used singly or in combination of two or more of them.

  In addition, the resin composition for forming a resin layer that is in a liquid state supplied from the tank to the heads 52 and 53 may have the same viscosity or different viscosities. The adjustment of the viscosity of the resin composition for forming a resin layer is, for example, appropriately setting the content of a solvent or a dispersion medium used in preparing the resin composition for forming a resin layer, and appropriately setting the content of a filler. This can be done by appropriately setting the temperature at which the resin composition for forming a resin layer is heated to a molten state (softened state).

  As shown in FIG. 3, the drying means 60 has a pair of hot air supply units 61. These hot air supply units 61 are arranged between the tensioner 43 and the tensioner 44 at positions downstream of the coating means 50 in the conveying direction of the metal foil 4A so as to face each other with the metal foil 4A interposed therebetween. And supported and fixed to the frame that supports the entire coating apparatus 100. Each hot air supply section 61 has a built-in heater (not shown) made of a heating wire, and the hot air heated by this heater passes through a plurality of hot air supply holes (not shown) in the metal foil 4A. Against. Thereby, the liquid film laminated body (resin composition for forming a liquid resin layer) 31 applied on the metal foil 4A is dried, and the resin layer forming layer (covering layer) 5A is formed on the metal foil 4A. It is formed.

  When the resin composition for forming a resin layer is heated to a molten state (softened state) to form a liquid, cold air may be blown from the drying means 60, or the arrangement of the drying means 60. May be omitted.

  The resin layer forming layer (coating layer) 5A can be formed on the metal foil 4A by the coating method (the coating method of the present invention) using the coating apparatus 100 having the above configuration.

(Coating method)
In this embodiment, this coating method is performed by applying a liquid resin layer forming resin composition (coating layer forming material) on the upper surface of a sheet-like metal foil (sheet base material) 4A. The first step of forming the first liquid coating 31A and the resin layer forming resin composition (coating layer forming material) that forms a liquid are applied to the upper surface of the first liquid coating 31A. The second step of forming the second liquid coating 31B, and the liquid coating laminate 31 that is a laminate of the first liquid coating 31A and the second liquid coating 31B coated on the upper surface of the metal foil 4A. And a third step of forming the resin layer forming layer 5A.

Hereinafter, each of these steps will be described sequentially.
<First step>
First, the first resin layer forming resin composition (first liquid material) is applied to the upper surface of the metal foil 4A while the sheet-like metal foil 4A is conveyed in the conveying direction. The liquid coating 31A is formed (see FIGS. 3 and 4).

  (1-1) First, the metal foil 4A is unwound from the unwinding roller 46 on which the metal foil 4A is pre-wound so that the middle of the metal foil 4A is in contact with the tensioners 41 to 44 along the conveying direction. Mounted on the take-up roller 48.

  Then, the metal foil 4 </ b> A is transported in the transport direction by the operation of a motor connected to the winding roller 48.

  The metal foil 4A has a conveyance speed of preferably 3 m / min or more and 16 m / min or less, and more preferably 4 m / min or more and 7 m / min or less. Even if the conveying speed is set within such a range, as described later, after the first liquid coating 31A is applied, the second liquid coating 31B is further applied on the first liquid coating 31A. By adopting a configuration for obtaining the liquid film laminate 31, even if the liquid film laminate 31 is thick, it is possible to accurately suppress the entrainment of air (gas) into the liquid film laminate 31 or Can be prevented. Therefore, it is possible to accurately suppress or prevent the generation of bubbles in the resin layer forming layer 5A obtained by drying the liquid film laminate 31.

  (1-2) Next, a resin composition for forming a resin layer that is in a liquid state is applied to the metal foil 4A as a coating film from the first head 52 that is disposed opposite to the tensioner 42 with the metal foil 4A interposed therebetween. The first liquid coating 31A is formed on the metal foil 4A by coating (supplying) the metal foil 4A unwound from the unwinding roller 46 (see FIGS. 3 and 4).

  The film thickness of the first liquid coating 31A is preferably 3 μm or more and 150 μm or less, and more preferably 30 μm or more and 120 μm or less.

  The liquid resin layer forming resin composition used for forming the first liquid coating 31A preferably has a viscosity of 3 cP or more and 1500 cP or less, more preferably 10 cP or more and 1000 cP or less. .

  By setting the film thickness and the viscosity in such a range, not only can air be accurately restrained or prevented during the formation of the first liquid coating 31A, but also the second described later. In the step, it is possible to accurately suppress or prevent air from being caught in the second liquid coating 31B formed on the first liquid coating 31A.

  According to said 1st process, since the film thickness of 31 A of 1st liquid films formed so that it is preferably 3 micrometers or more and 150 micrometers or less is set thin, metal foil 4A with the conveyance speed as mentioned above. Even when the first liquid coating 31A is formed by conveying the air, it is possible to accurately suppress or prevent the formation of the first liquid coating 31A in a state where air is entrained.

<Second step>
Next, while transporting the metal foil 4A on which the first liquid coating 31A is formed in the transport direction, a resin layer that forms a liquid is further formed on the upper surface of the first liquid coating 31A formed on the metal foil 4A. The second liquid coating 31B is formed by applying the resin composition (second liquid material) (see FIGS. 3 and 5).

  Thereby, the liquid film laminate 31 in which the first liquid film 31A and the second liquid film 31B are laminated in this order is formed on the metal foil 4A.

  (2-1) First, the metal foil 4A on which the first liquid coating 31A is formed is transported from the tensioner 42 side to the tensioner 43 side (in the transport direction) by the operation of a motor connected to the winding roller 48. .

  (2-2) Next, with the metal foil 4A interposed between the tensioner 43 and the second head 53 disposed oppositely, the resin composition for forming a resin layer that is liquid is used as a coating film to form the metal foil 4A. The second liquid coating 31B is formed on the first liquid coating 31A by coating (supplying) the first liquid coating 31A formed thereon (see FIGS. 3 and 5).

  The film thickness of the second liquid coating 31B is preferably 50 μm or more and 500 μm or less, and more preferably 100 μm or more and 250 μm or less.

  Further, the resin composition for forming a liquid resin layer (second liquid material) used for forming the second liquid coating 31B preferably has a viscosity of 100 cP or more and 500 cP or less, and 150 cP or more and 300 cP or more. The following is more preferable.

  By setting the film thickness and the viscosity in such a range, it is possible to accurately suppress or prevent air from being involved when the second liquid coating 31B is formed on the first liquid coating 31A. it can.

  According to the above steps, the first liquid coating 31A is formed in advance on the metal foil 4A prior to the formation of the second liquid coating 31B. Therefore, even if the thickness of the second liquid coating 31B formed to be preferably 50 μm or more and 500 μm or less is set thick, the second liquid coating 31B is formed in a state where air is entrained. Can be accurately suppressed or prevented.

<Third step>
Next, coating is performed on the upper surface of the metal foil 4A while the metal foil 4A on which the liquid film laminate 31 that is a laminate of the first liquid film 31A and the second liquid film 31B is formed is conveyed in the conveyance direction. By drying the liquid coating laminate 31 thus formed, the resin layer forming layer 5A is formed.

  (3-1) First, the metal foil 4A on which the liquid film laminate 31 is formed is transported from the tensioner 43 side to the tensioner 44 side (in the transport direction) by the operation of a motor connected to the winding roller 48.

  (3-2) Next, the liquid film laminate (liquid resin) is formed by the drying means 60 at a position downstream of the coating means 50 in the conveying direction of the metal foil 4A between the tensioner 43 and the tensioner 44. By drying the layer forming resin composition 31, the resin layer forming layer 5 </ b> A is formed on the metal foil 4 </ b> A.

  The temperature of the liquid film laminate 31 when drying the liquid film laminate 31 is preferably 40 ° C. or higher and 150 ° C. or lower, and more preferably 50 ° C. or higher and 120 ° C. or lower. Thereby, the liquid film laminated body 31 can be dried reliably and the resin layer forming layer 5A can be formed. Further, since it is possible to accurately suppress or prevent the solvent or dispersion medium from remaining in the resin layer forming layer 5A, the characteristics of the resin layer forming layer 5A can be attributed to the remaining solvent or dispersion medium. Can be reliably reduced.

  (3-3) Next, the obtained laminated body 7A of the metal foil 4A and the resin layer forming layer 5A is wound (wound) by the winding roller 48 after passing through the tensioner 44.

  Thereby, in the state wound by the winding roller 48, the laminated body 7A in which the metal foil 4A and the resin layer forming layer 5A are laminated in this order can be continuously obtained.

  The laminated body 7A is manufactured through the first to third steps described above, but the film thickness of the liquid film laminated body 31 can be reduced by adopting such a configuration of the first to third steps. Even if it is thick, it is formed by laminating the thin first liquid coating 31A on the metal foil 4A prior to the application of the second liquid coating 31B. It is possible to accurately suppress or prevent air (gas) from being entrained in the liquid film laminate 31. Therefore, it is possible to accurately suppress or prevent the generation of bubbles in the resin layer forming layer 5A obtained by drying the liquid film laminate 31.

  In this embodiment, when the coating method of the present invention is applied to the formation of the resin layer forming layer 5A on the metal foil 4A, in other words, the metal foil 4A constitutes the base sheet, and the resin layer Although the case where the forming layer 5A constitutes the coating layer has been described, the structure is not limited to this.

  That is, the formation of the insulating portion 6 on the resin layer forming layer 5A provided on the metal foil 4A, in other words, the laminate of the metal foil 4A and the resin layer forming layer 5A constitutes the base sheet, The coating method of the present invention can also be applied when the insulating portion 6 constitutes a coating layer.

  Further, as in the present embodiment, the same resin layer forming resin composition (coating layer forming material) or the same kind of resin layer forming resin composition having different viscosities are used for the first head 52 and the second head. When the resin layer forming layer 5A is formed by coating from the head 53, that is, in the case of forming one coating layer, different coating layer forming materials are used for the first head 52 and the first coating layer. Two coating layers may be applied to form two different coating layers.

  As mentioned above, although the coating apparatus of the present invention, the coating method, the metal foil tension substrate, the circuit board, the electronic component mounting substrate, and the electronic device have been described with respect to the illustrated embodiments, the present invention is not limited thereto. .

  For example, each part constituting the coating apparatus, the metal foil-clad substrate, the circuit board, the electronic component mounting board, and the electronic device of the present invention can be replaced with an arbitrary structure that can exhibit the same function. Moreover, arbitrary components may be added.

  Moreover, in the coating method of this invention, the pre-process of a 1st process, the intermediate process which exists between 1st-3rd processes, or the post process of a 3rd process is added for arbitrary purposes. You may do it.

  Furthermore, it goes without saying that the electronic component mounting substrate of the present invention is not limited to that of the above-described embodiment, that is, not limited to the electronic component mounting semiconductor device. Equipped with resistors, capacitors, diode power MOSFETs, power transistors such as insulated gate bipolar transistors (IGBTs), reactors, LEDs (light emitting diodes), LDs (laser diodes), light emitting elements such as organic EL elements, motors, etc. Applicable to what to do.

  Moreover, these electronic component mounting boards can be incorporated into various electronic devices, and the electronic devices are not particularly limited. For example, mobile phones, game machines, router devices, WDM devices, televisions, home servers, personal computers, etc. Computers, electronic paper, car navigation devices, supercomputers, blood pressure monitors, blood glucose meters and the like can be mentioned.

  Hereinafter, specific examples of the present invention will be described. Note that the present invention is not limited to this.

1. Preparation of coating layer forming material KF-96-10CS, KF-96-200CS, and KF-96-1000CS were prepared as silicone oils having viscosities of 10 cP, 200 cP, and 1000 cP, respectively, and these were formed as coating layers having different viscosities. It was decided to use it as a material.

2. Examination of film thickness of first liquid coating (Example 1A)
[1] First, a copper foil having a thickness of 45 mm is prepared as a base sheet, and a coating layer forming material having a viscosity of 200 cP is extruded from a die coater by a slot die method while the copper foil is conveyed in the conveying direction. By coating, a first liquid film having a thickness of 30 μm was formed on the upper surface of the copper foil.

  [2] Next, while transporting the copper foil on which the first liquid film is formed in the transport direction, the coating layer forming material having a viscosity of 200 cP is extruded from the die coater and applied by the slot die method. A second liquid film having a thickness of 120 μm was formed on the upper surface of the first liquid film on the copper foil.

  In the formation of the second liquid film by the process [2] as described above, bubbles are generated in the second liquid film by changing the transport speed in the transport direction of the copper foil to 4 to 16 m / min. The critical speed to become was measured.

(Example 2A)
In the step [1], the critical speed was measured in the same manner as in Example 1A, except that the thickness of the first liquid film formed on the upper surface of the copper foil was 60 μm.

(Example 3A)
In step [1], the critical speed was measured in the same manner as in Example 1A, except that the thickness of the first liquid film formed on the upper surface of the copper foil was 120 μm.

(Comparative Example 1A)
The critical speed was measured in the same manner as in Example 1A, except that the formation of the first liquid film on the upper surface of the copper foil in Step [1] was omitted.

  FIG. 6 shows the relationship between the thickness of the first liquid film and the critical speed in each Example and Comparative Example, measured as described above.

  As can be seen from the example of FIG. 6, by setting the film thickness of the first liquid film to be thick, it is possible to prevent the generation of bubbles in the second liquid film even when the conveyance speed is 10 m / min. It became.

  On the other hand, in Comparative Example 1A, the formation of the first liquid film is omitted, and bubbles are generated in the second liquid film even at a conveyance speed of less than 10 m / min. became.

3. Examination of viscosity of first liquid coating (Example 1B)
[1] First, a copper foil having a thickness of 45 mm is prepared as a base sheet, and a material for forming a coating layer having a viscosity of 10 cP is extruded from a die coater by a slot die method while the copper foil is conveyed in the conveying direction. By coating, a first liquid film having a thickness of 120 μm was formed on the upper surface of the copper foil.

  [2] Next, while transporting the copper foil on which the first liquid film is formed in the transport direction, the coating layer forming material having a viscosity of 200 cP is extruded from the die coater and applied by the slot die method. A second liquid film having a thickness of 240 μm was formed on the upper surface of the first liquid film on the copper foil.

  In the formation of the second liquid film by the process [2] as described above, bubbles are generated in the second liquid film by changing the transport speed in the transport direction of the copper foil to 4 to 16 m / min. The critical speed to become was measured.

(Example 2B)
In the step [1], the critical speed was measured in the same manner as in Example 1B, except that the material for forming the coating layer applied to the upper surface of the copper foil was a material having a viscosity of 200 cP.

(Example 3B)
In the step [1], the critical speed was measured in the same manner as in Example 1B, except that the material for forming the coating layer applied on the upper surface of the copper foil was a material having a viscosity of 1000 cP.

  FIG. 7 shows the relationship between the viscosity and the critical speed of the first liquid film in each Example, measured as described above.

  As is apparent from the example of FIG. 7, by setting the viscosity of the first liquid film to be low, even if the conveying speed is increased, it is possible to prevent the generation of bubbles in the second liquid film. It was.

DESCRIPTION OF SYMBOLS 1 Semiconductor device 4 Wiring 4A Metal foil 5 Resin layer 5A Resin layer formation layer 6 Insulation part 7A Laminate body 8 Base material 10 Circuit board 10A Metal foil tension board 11 Mold part 12 Connection terminal 31 Liquid film laminated body 31A 1st liquid Coating 31B Second liquid coating 40 Conveying means 41 Tensioner 42 Tensioner 43 Tensioner 44 Tensioner 46 Tensioner 46 Unwinding roller 48 Winding roller 50 Coating means 52 First head 53 Second head 55 Electronic component mounting substrate 60 Drying means 61 Hot air Supply unit 100 Coating device

Claims (12)

A coating apparatus that forms a coating layer by coating a liquid coating layer forming material on one surface of the substrate sheet by a slot die method while transporting the substrate sheet in the transport direction. ,
Conveying means for conveying the substrate sheet along the conveying direction; and coating means for applying the coating layer forming material to one surface of the substrate sheet,
The coating means includes: a first die coater that coats the coating layer forming material on one surface of the base sheet to form a first liquid film; and the first die coater A second die coat disposed at a predetermined distance on the downstream side in the conveying direction, and applying the coating layer forming material to one surface of the first liquid coating to form a second liquid coating. A coating apparatus comprising: a coating device.   Drying means for forming the coating layer by drying the liquid film laminate formed by laminating the first liquid film and the second liquid film formed on one surface of the base sheet; The coating apparatus of Claim 1 with which the said coating means is provided in the downstream of the said conveyance direction.   3. The coating apparatus according to claim 1, wherein the first liquid coating is formed within a thickness range of 3 μm to 150 μm.   The coating apparatus according to any one of claims 1 to 3, wherein the coating layer forming material used for forming the first liquid film has a viscosity set in a range of 3 cP or more and 1500 cP or less. .   5. The coating apparatus according to claim 1, wherein the second liquid film is formed within a range of 50 μm or more and 500 μm or less.   The coating apparatus according to claim 1, wherein the coating layer forming material used for forming the second liquid film has a viscosity set in a range of 100 cP or more and 500 cP or less. .   The coating apparatus of any one of Claim 1 thru | or 6 with which the conveyance speed which conveys the said base material sheet in the said conveyance direction is set to 3 m / min or more and 16 m / min or less. A coating method of forming a coating layer by coating a liquid coating layer forming material on one surface of the substrate sheet by a slot die method while transporting the substrate sheet in the transport direction. ,
A first step of forming the first liquid film by applying the coating layer forming material to one surface of the base sheet while transporting the base sheet along the transport direction;
A second step of applying the coating layer forming material to one surface of the first liquid coating to form a second liquid coating;
A third step of obtaining the coating layer by drying a liquid film laminate formed by laminating the first liquid film and the second liquid film formed on one surface of the base sheet; The coating method characterized by having. In the coating method according to claim 8, the base sheet is a metal foil, and the coating layer contains a resin material,
A metal foil-clad substrate, wherein the coating layer formed by the coating method according to claim 8 is laminated on the metal foil. A circuit board formed using the metal foil-clad substrate according to claim 9,
A circuit board comprising a circuit provided with terminals for electrically connecting electronic components formed by patterning the metal foil.   An electronic component mounting board comprising: the circuit board according to claim 10; and the electronic component electrically connected to the terminal and mounted on the circuit board.   An electronic device comprising the electronic component mounting board according to claim 11.

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