JP6627284B2 - Metal film with resin layer and mounting board - Google Patents

Description

  The present invention relates to a metal film with a resin layer and a mounting substrate.

  As a substrate on which electronic components and the like are mounted, a metal film with a resin layer having a metal film for forming a circuit and a resin layer made of an insulating resin material is used.

  As such a substrate (metal film with a resin layer), an inexpensive rigid substrate is widely used.

  However, a certain amount of bending is required for a substrate installed in a narrow space such as the inside of a mobile device, a substrate used for an LED lighting device having a curved light-emitting surface, a substrate for a rear lamp / daylight of an automobile, and the like. Therefore, it is difficult to apply a rigid substrate.

  For this reason, expensive flexible substrates have been used for the above-mentioned applications (for example, see Patent Document 1).

  The flexible substrate generally has extremely high performance, such as heat resistance of 300 ° C. or higher and durability that can withstand many bendings.

  However, for such applications, such excessive performance is not required. At present, a flexible substrate having excessive performance is used, and the cost-effectiveness is extremely low.

  Further, from the viewpoint of workability when mounting electronic components and the like, it is required that the substrate does not warp.

JP 2013-243028 A

  An object of the present invention is to provide a metal film with a resin layer which is inexpensive and has sufficient bending resistance and heat resistance and prevents the occurrence of unintended warpage, and is also inexpensive and has sufficient bending resistance and heat resistance. It is an object of the present invention to provide a mounting board which has an undesired warpage.

Such an object is achieved by the present invention described in the following (1) to ( 12 ).
(1) a metal film;
A resin layer made of a material containing a cured product of a curable resin having an epoxy group,
The flexural modulus of the resin layer measured according to ASTM-D-790 is 10 MPa or more;
The resin layer has a tensile elongation (elongation at break) of 3% or more measured according to ASTM-D-882,
Bow is measured by JIS-C-6471, wherein the method is Ri der 5%,
The cured product curable resin is cured, the epoxy equivalent is 5,000 or more phenoxy resins, polyfunctional epoxy compound, characterized in der Rukoto that reacts with a resin layer metal film.

(2) a metal film;
With a resin layer made of a material containing a curable resin having an epoxy group,
The flexural modulus of the resin layer measured according to ASTM-D-790 is 10 MPa or more;
The resin layer has a tensile elongation (elongation at break) of 3% or more measured according to ASTM-D-882,
Wherein Ri der warp ratio is less than 5% as measured by JIS-C-6471 according to the method described in a state where the curable resin is cured,
The cured product curable resin is cured, the epoxy equivalent is 5,000 or more phenoxy resins, polyfunctional epoxy compound, characterized in der Rukoto that reacts with a resin layer metal film.

  (3) The metal film with a resin layer according to the above (1) or (2), wherein the resin layer contains a flexible component.

  (4) The flexible component reacts with the curable resin by a functional group capable of reacting with the curable resin, and constitutes a part of molecules of a cured product in the resin layer. A) a metal film with a resin layer described in

  (5) The metal film with a resin layer according to (3) or (4), wherein the content of the flexible component in the resin layer is from 20% by mass to 60% by mass.

  (6) The resin-coated metal film according to any one of the above (1) to (5), wherein the resin layer contains 5 to 65 parts by mass of an inorganic filler.

  (7) The metal film with a resin layer according to any one of (1) to (6), wherein the resin layer has a tensile storage modulus at 100 ° C. of 1 MPa or more in a state where the curable resin is cured.

  (8) The metal film with a resin layer according to any one of (1) to (7), wherein the curable resin has an epoxy equivalent of 100 or more.

( 9 ) The metal film with a resin layer according to any one of (1) to ( 8 ), wherein the resin layer has a volume resistivity of 1 × 10 ¹³ Ω · cm or more.

( 10 ) The metal film with a resin layer according to any one of (1) to ( 9 ), wherein the thickness of the resin layer is 10 μm or more and 1000 μm or less.

( 11 ) The metal film with a resin layer according to any one of (1) to ( 10 ), wherein the thickness of the metal film is 5 μm or more and 1000 μm or less.

( 12 ) A mounting board obtained by mounting an electronic component using the metal film with a resin layer according to any one of (1) to ( 11 ).

  According to the present invention, it is possible to provide a metal film with a resin layer which is inexpensive and has sufficient bending resistance and heat resistance and prevents occurrence of unintended warpage, and is inexpensive and has sufficient bending resistance and heat resistance And a mounting board in which undesired warpage is prevented.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the suitable embodiment of the metal film with a resin layer of this invention typically. It is sectional drawing which shows the suitable embodiment of the mounting board of this invention typically.

Hereinafter, the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
金属 Metal film with resin layer≫
First, the metal film with a resin layer of the present invention will be described.

FIG. 1 is a cross-sectional view schematically showing a preferred embodiment of the metal film with a resin layer of the present invention.
In addition, the drawings referred to in this specification show a part of the configuration in an exaggerated manner, and do not accurately reflect an actual dimensional ratio or the like.

The metal film with a resin layer 10 includes a metal film 1 and a resin layer 2 having an insulating property.
The metal film with a resin layer 10 is used for manufacturing a circuit board and a mounting board.

<Metal film>
The metal film 1 is to be a circuit layer in a circuit board manufactured using the metal film with a resin layer 10.

  The metal film 1 may be formed of a metal material, for example, copper, aluminum, nickel, iron, tin, etc., and may include two or more kinds, but preferably, Cu or a Cu alloy. It is composed of

  Thereby, the circuit layer can be easily formed, and the conductivity of the circuit layer can be made particularly excellent. It is also preferable from the viewpoint of suppressing the creation cost of the metal film 10 with a resin layer.

  The thickness of the metal film 1 is not particularly limited, but is preferably 5 μm or more and 1000 μm or less.

  When the thickness of the metal film 1 is within the above range, the flexibility and the durability of the metal film with a resin layer 10 and the circuit board and the mounting board manufactured using the same are made particularly excellent. Flexibility can be made particularly excellent. Further, when the thickness of the metal film 1 is within the above range, the workability when processing the metal film 1 into a circuit is excellent, and the circuit to be formed is suitably applied to high current applications. can do.

  The metal film 1 may have a uniform composition at each part or may have parts having different compositions. For example, the metal film 1 may be a laminate having a plurality of layers having different compositions, or may be formed of a gradient material whose composition changes in a gradient direction in the thickness direction.

<Resin layer>
The resin layer 2 functions as an insulating layer in a circuit board and a mounting board.

  The resin layer 2 is made of a material containing at least one of a curable resin having an epoxy group (B-stage resin material) and a cured product of a curable resin having an epoxy group (C-stage resin material). is there.

  When the resin layer 2 contains a curable resin having an epoxy group (B-stage resin material), when the mounting board on which the electronic components are mounted is used, the curable resin (B-stage resin) is cured by a curing reaction. The resin material) is in a cured state (C stage).

  A curable resin having an epoxy group is generally less expensive than polyimide or the like used for a flexible substrate, and is advantageous in reducing the cost of a metal film with a resin layer.

A cured product of a curable resin having an epoxy group (C-stage resin material) generally has sufficient insulating properties and heat resistance, and is used for special purposes (for example, when used at an environmental temperature of 250 ° C. or more). , The characteristics required for the insulating layer of the circuit board are sufficiently satisfied.
The resin layer 2 satisfies the following conditions.

  That is, the flexural modulus of the resin layer 2 measured according to ASTM-D-790 is 10 MPa or more, and the resin layer 2 measured according to ASTM-D-882 has a tensile elongation (elongation at break). Degree) is 3% or more.

  By satisfying such conditions, the metal film 10 with the resin layer, the circuit board manufactured using the same, and the mounting board have sufficient flexibility and bending resistance. Substrates that require a certain degree of flexibility, such as substrates that are installed in such narrow spaces, substrates that are used for LED lighting equipment that has curved light-emitting surfaces, and substrates for rear lamps and daylights in automobiles. It can be suitably applied.

  On the other hand, if these conditions are not satisfied, the above-described excellent effects cannot be obtained.

  That is, if the flexural modulus of the resin layer 2 is too small, sufficient stiffness (tension) cannot be obtained, and component mounting and handling become difficult.

  On the other hand, when the tensile elongation (elongation at break) of the resin layer 2 is too small, sufficient flexibility cannot be obtained, and it is difficult to apply the resin layer 2 to the above-mentioned applications.

  As described above, the flexural modulus of the resin layer 2 measured according to ASTM-D-790 may be 10 MPa or more, but is preferably 10 MPa or more and 10 GPa or less.

  As a result, the above-described effects are more remarkably exhibited, and workability when mounting electronic components on a circuit board manufactured using the metal film with a resin layer 10 is particularly improved. it can.

  The tensile elongation (elongation at break) of the resin layer 2 measured according to ASTM-D-882 may be 3% or more, but is preferably 5% or more, and is 30% or more and 300% or less. Is more preferable.

  As a result, the above-described effects are more remarkably exhibited, and workability when mounting electronic components on a circuit board manufactured using the metal film with a resin layer 10 is particularly improved. it can.

  The flexural modulus can be determined, for example, by measurement using a three-point bending test with Tensilon.

  The tensile elongation (elongation at break) can be determined, for example, by measurement using a tensile test with Tensilon or the like.

  As described above, the resin layer 2 is made of a material containing at least one of a curable resin having an epoxy group (B-stage resin material) and a cured product of a curable resin having an epoxy group (C-stage resin material). Any resin may be used. If the resin layer 2 is made of a material containing a curable resin having an epoxy group (B-stage resin material), the B-stage resin material has excellent bonding properties. (Adhesion) can be exhibited, so that the member can be suitably joined (adhered) to the resin layer 2 side. More specifically, for example, a mounting substrate manufactured using the metal film with a resin layer 10 is provided on the resin layer 2 side with a heat radiating member (for example, a heat radiating member made of a material having a thermal conductivity such as Al). Can be suitably obtained as a bonded product.

  When the resin layer 2 is made of a material containing a cured product of a curable resin having an epoxy group (C-stage resin material), it is manufactured using a metal film with a resin layer and a metal film with a resin layer. Thus, the dimensional accuracy of the circuit board to be manufactured can be made more excellent, and the electronic components can be more suitably mounted at the time of manufacturing the mounting board. Further, the reflow heat resistance can be further improved.

  The glass transition temperature (Tg) of the above-mentioned cured product of the curable resin having an epoxy group (C-stage resin material) is preferably 50 ° C. or higher, more preferably 70 ° C. or higher and 250 ° C. or lower.

  Accordingly, in a wide range of applications as described above, sufficient heat resistance and durability can be sufficiently exhibited, and the production cost of the metal film 10 with a resin layer can be suppressed. In addition, a metal film 10 with a resin layer including a resin material of the C stage (including a circuit board and a mounting board), a metal film 10 with a resin layer in a state where the resin material of the B stage is in the C stage (a circuit board, (Including the mounting board) can be made particularly excellent in flexibility and bending resistance.

  The glass transition temperature can be measured as follows based on, for example, JIS C6481.

  That is, a tensile load is applied under a nitrogen atmosphere (200 ml / min) using a dynamic viscoelasticity measuring device (for example, DMA / 983 manufactured by TA Instruments Co., Ltd.) at a frequency of 1 Hz and -50 ° C. From 300 ° C. to a temperature of 5 ° C./min, and the glass transition temperature Tg can be determined from the peak position of tan δ.

  The dielectric breakdown voltage of the resin layer 2 is preferably 30 kV / mm or more, and more preferably 50 kV / mm or more.

  Examples of the curable resin having an epoxy group include bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol E epoxy resin, bisphenol M epoxy resin, bisphenol P epoxy resin, and bisphenol Z. Bisphenol epoxy resins such as epoxy resins, phenol novolak epoxy resins, novolak epoxy resins such as cresol novolak epoxy resins, biphenyl epoxy resins, arylalkylene epoxy resins such as phenol aralkyl epoxy resins having a biphenylene skeleton, Naphthalene epoxy resin, anthracene epoxy resin, phenoxy epoxy resin, dicyclopentadiene epoxy resin, norbornene epoxy resin Adamantane type epoxy resin, epoxy resins such as a fluorene epoxy resin.

  The epoxy equivalent of the curable resin having an epoxy group is preferably 100 or more, more preferably 150 or more and 5000 or less.

  Thereby, the flexibility, bending resistance, and heat resistance of the metal film with a resin layer 10 and the circuit board and the mounting board manufactured using the same can be particularly excellent.

  The curable resin having an epoxy group preferably contains an epoxy resin having at least one of an aromatic ring structure and an alicyclic structure (alicyclic carbon ring structure).

  By using such an epoxy resin, the glass transition temperature can be increased, and the strength and thermal conductivity of the resin layer 2 can be particularly excellent.

  Examples of the epoxy resin having an aromatic ring or alicyclic structure include bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol E epoxy resin, bisphenol M epoxy resin, and bisphenol P epoxy resin. Having a bisphenol-type epoxy resin such as a bisphenol Z-type epoxy resin, a phenol novolak-type epoxy resin, a cresol novolak-type epoxy resin, a novolak-type epoxy resin such as a tetraphenol-based ethane-type novolak-type epoxy resin, a biphenyl-type epoxy resin, and a biphenylene skeleton. Examples include an arylalkylene type epoxy resin such as a phenol aralkyl type epoxy resin and an epoxy resin such as a naphthalene type epoxy resin. One of these can be used alone, or two or more can be used in combination.

  In addition, the glass transition temperature can be further increased, the generation of voids in the resin layer 2 can be suppressed, the strength and thermal conductivity of the resin layer 2 can be further improved, and the dielectric breakdown voltage can be improved. Therefore, as the epoxy resin, a naphthalene type epoxy resin is particularly preferable. Here, the naphthalene type epoxy resin refers to a resin having a naphthalene ring skeleton and having two or more glycidyl groups (epoxy groups).

  The total amount of the epoxy resin constituting the curable resin: the content of the naphthalene type epoxy resin to 100 parts by mass is preferably from 20 parts by mass to 80 parts by mass, and more preferably from 40 parts by mass to 60 parts by mass. . Thereby, the above-described effects are more remarkably exhibited.

  As the naphthalene type epoxy resin, for example, a resin represented by the following formula (5), a resin represented by the following formula (6), a resin represented by the following formula (7), or the like can be used. In the following formula (6), m and n each represent the number of substituents on the naphthalene ring, and each independently represents an integer of 1 or more and 7 or less. In the following formula (7), Me represents a methyl group, and l, m, and n are integers of 1 or more. However, it is preferable that l, m, and n are 10 or less.

  Among the compounds of the above formula (6), those represented by the following formulas (6-1), (6-2) and (6-3) are particularly preferable.

  Further, as the naphthalene type epoxy resin, a naphthylene ether type epoxy resin represented by the following formula (8) can also be used.

（上記式（８）において、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。）

(In the above formula (8), n is an integer of 1 or more and 20 or less, 1 is an integer of 1 or more and 2 or less, and R ₁ is each independently a hydrogen atom, a benzyl group, an alkyl group, or a compound of the following formula (9) Wherein R ₂ is independently a hydrogen atom or a methyl group.)

（上記式（９）において、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。）

(In the above formula (9), 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.)

  Among the naphthylene ether type epoxy resins represented by the above formula (8), particularly preferred are, for example, those represented by the following formula (10).

（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. R is each independently a hydrogen atom or (The structure is represented by the following formula (11), and is 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.)

  Particularly preferred among the naphthylene ether type epoxy resins represented by the above formula (10) are, for example, the following formulas (12), (13), (14), (15), One represented by the formula (16) is given.

  Further, as the epoxy resin, an epoxy resin having higher flexibility than the above-described epoxy resin (an epoxy resin as a flexible component) can be used. For example, an aliphatic epoxy resin having no aromatic ring structure and no alicyclic structure (alicyclic carbon ring structure), an epoxy resin having a polydiene skeleton, an epoxy resin having an n-alkylene group having 4 or more carbon atoms, or the like is used. be able to.

  As a result, the flexibility and bending resistance of the metal film with a resin layer 10 and the circuit board and the mounting board manufactured using the same, which are sufficiently excellent in insulation and durability, are particularly improved. be able to.

  In particular, by using an epoxy resin having a polydiene skeleton, the flexibility and bending resistance of the metal film 10 with a resin layer, a circuit board and a mounting board manufactured using the same, and the adhesion between the metal film 1 and the resin layer 2 Properties can be made particularly excellent.

  In addition, by using an epoxy resin having an n-alkylene group having 4 or more carbon atoms, the metal film 10 with a resin layer, the circuit board manufactured using the same, the flexibility and bending resistance of the mounting board, and the metal film 1 The adhesion between the resin layer 2 and the resin layer 2 can be made particularly excellent.

  Examples of the epoxy resin having a polydiene skeleton include those represented by the following formulas (18) and (26).

（式（１８）において、ｌ、ｍ、ｎ、ｐ、ｑ、ｒは、それぞれ独立に０以上の整数、ただし、ｌ、ｍ、ｎがすべて０の場合を除く。また、ｐ、ｑ、ｒがすべて０の場合も除く。）

(In the formula (18), l, m, n, p, q, and r are each independently an integer of 0 or more, provided that l, m, and n are all 0. Also, p, q, and r Also excludes all 0.)

（式（２６）において、ｌ、ｍ、ｎは、それぞれ独立に０以上の整数、ただし、ｌ、ｍ、ｎがすべて０の場合を除く。）

(In the formula (26), l, m, and n are each independently an integer of 0 or more, except that all of l, m, and n are 0.)

  By including such an epoxy resin, the above-described effects are more remarkably exhibited.

  In the formula (18), l, m, n, p, q, and r may be each independently an integer of 0 or more, but l is preferably an integer of 1 or more and 5 or less, and m is 5 or more. It is preferably an integer of 20 or less, n is preferably an integer of 0 or more and 8 or less, p is preferably an integer of 0 or more and 8 or less, and q is an integer of 3 or more and 12 or less. Preferably, r is an integer of 0 or more and 4 or less.

  In the formula (26), l, m, and n may be each independently an integer of 0 or more, but l is preferably an integer of 1 or more and 12 or less, and m is an integer of 8 or more and 30 or less. And n is preferably an integer of 0 or more and 10 or less.

  Examples of the epoxy resin having an n-alkylene group having 4 or more carbon atoms include those represented by the following formulas (19) and (20).

  By including such an epoxy resin, the above-described effects are more remarkably exhibited.

  Further, by using an epoxy resin having at least one of an aromatic ring structure and an alicyclic structure (alicyclic carbon ring structure) in combination with an epoxy resin having high flexibility as described above, a metal with a resin layer can be obtained. The flexibility and bending resistance of the film 10 and the circuit board and the mounting board manufactured using the film 10 can be particularly excellent, and the heat resistance and the like can be particularly excellent.

When an epoxy resin having at least one of an aromatic ring structure and an alicyclic structure (alicyclic carbon ring structure) and an epoxy resin having high flexibility (flexible epoxy resin) as described above are used in combination, Epoxy resin having at least one of an aromatic ring structure and an alicyclic structure (alicyclic carbon ring structure) contained in a cured product in a cured state (C-stage state) of the curable resin constituting layer 2 Is Xc [mass%], and the above-described highly flexible epoxy resin (flexible epoxy) contained in the cured product in a state where the curable resin constituting the resin layer 2 is cured (C-stage state) When the content of the (resin) is Xf [mass%], it is preferable that the relationship of 0.1 ≦ Xc / Xf ≦ 0.8 is satisfied, and the relationship of 0.3 ≦ Xc / Xf ≦ 0.7 is satisfied. More to do Masui.
Thereby, the above-described effects are more remarkably exhibited.

As the curable resin having an epoxy group, a phenoxy resin may be used.
Thereby, the flexibility and the bending resistance of the metal film 10 with the resin layer, the circuit board and the mounting board manufactured using the same can be made particularly excellent.

  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, a phenoxy resin having a biphenyl skeleton, and a phenoxy resin having an imide skeleton. Further, a phenoxy resin having a structure having a plurality of these skeletons can also be used.

  Among these, it is preferable to use a phenoxy resin of bisphenol A type or bisphenol F type, a phenoxy resin having an imide skeleton, or a phenoxy resin having a bisphenol acetophenone skeleton. Further, a phenoxy resin having a plurality of skeletons may be used.

The weight average molecular weight of the phenoxy resin is not particularly limited, but is preferably from 5.0 × 10 ^{3 to} 8.0 × 10 ⁴ .

  In addition, in this specification, the weight average molecular weight is a value in terms of polystyrene measured by gel permeation chromatography (GPC) unless otherwise specified.

Further, an epoxy resin and a phenoxy resin as described above may be used in combination.
Thereby, the flexibility and bending resistance of the metal film with resin layer 10 and the circuit board and the mounting board manufactured using the same can be particularly excellent, and the heat resistance and the like can be particularly excellent.

  In particular, the cured product obtained by curing the curable resin is preferably obtained by reacting a phenoxy resin having an epoxy equivalent of 5,000 or more with a polyfunctional epoxy compound.

  Thereby, the flexibility and bending resistance of the metal film with resin layer 10 and the circuit board and the mounting board manufactured using the same can be particularly excellent, and the heat resistance and the like can be particularly excellent.

  When the epoxy resin and the phenoxy resin as described above are used in combination, the content of the epoxy resin contained in the cured product of the curable resin is set to Xe [% by mass], and the curing of the curable resin is performed. When the content of the phenoxy resin contained in the product is defined as Xp [mass%], it is preferable to satisfy the relationship of 0.4 ≦ Xe / Xp ≦ 2.8, and 0.5 ≦ Xe / Xp ≦ 2. .5 is more preferably satisfied.

  Thereby, the effect of using the epoxy resin and the phenoxy resin together as described above is more remarkably exhibited.

  In addition, the cured product obtained by curing the curable resin may partially include a component other than the curable resin having an epoxy group as described above.

  For example, a cured product obtained by curing the curable resin has a functional group capable of reacting with a curable resin having an epoxy group in a molecule thereof, and a flexible component (resin layer) reacted with the curable resin by the functional group. (A component having a function of making 2 flexible).

  Thereby, the flexibility and bending resistance of the metal film with resin layer 10 and the circuit board and the mounting board manufactured using the same can be particularly excellent, and the heat resistance and the like can be particularly excellent.

  As such a soft component (a soft component constituting a part of the cured product), for example, a copolymer of acrylonitrile and butadiene containing a carboxyl group at a terminal (CTBN, for example, by the following formula (17): Wherein x is 0.05 or more and 0.2 or less, y is 0.8 or more and 0.95 or less (x and y indicate a molar ratio, and x + y = 1), and z is 50 or more and 70 or less. For example, trade name CTBN1300X (manufactured by Ube Industries), phenolic hydroxyl group-containing aromatic polyamide-poly (butadiene-acrylonitrile) block copolymer (for example, trade name KAYAAFLEX BPAM-155 (manufactured by Nippon Kayaku Co., Ltd., Amide group)).

  Thereby, the flexibility and bending resistance of the metal film with resin layer 10 and the circuit board and the mounting board manufactured using the same can be particularly excellent, and the heat resistance and the like can be particularly excellent.

  In particular, the cured product obtained by curing the curable resin is preferably obtained by reacting a phenoxy resin having an epoxy equivalent of 5,000 or more with a polyfunctional epoxy compound.

  Thereby, the flexibility and bending resistance of the metal film with resin layer 10 and the circuit board and the mounting board manufactured using the same can be particularly excellent, and the heat resistance and the like can be particularly excellent.

  The resin layer 2 may include a component other than the above-described cured product or the curable resin constituting the cured product.

  Examples of such a component include a filler, a soft component (a soft component that does not constitute a part of the cured product), an antioxidant, a coupling agent, an antifoaming agent, a leveling agent, and the like.

  Examples of the filler constituting the resin layer 2 include silicates such as talc, calcined clay, unfired clay, mica, and glass; oxides such as titanium oxide, alumina, boehmite, silica, and fused silica; Carbonates such as calcium carbonate, magnesium carbonate and hydrotalcite; hydroxides such as aluminum hydroxide, magnesium hydroxide and calcium hydroxide; sulfates or sulfites such as barium sulfate, calcium sulfate and calcium sulfite; zinc borate , Borate such as barium metaborate, aluminum borate, calcium borate, sodium borate; nitrides such as aluminum nitride, boron nitride, silicon nitride, carbon nitride; titanates such as strontium titanate, barium titanate And the like.

  The filler may have any shape such as a sphere, a needle, a fiber, a strand, and a scale.

  Further, the resin layer 2 may include a sheet-like member (particularly, a member having a void impregnated with a curable resin or the like) such as a glass nonwoven fabric and an aramid nonwoven fabric. Thereby, the durability and the like of the metal film 10 with the resin layer and the circuit board and the mounting board manufactured using the same can be made particularly excellent.

  In particular, if the resin layer 2 contains a filler (inorganic filler) composed of an inorganic material, the weight (specific gravity) of the metal film 10 with a resin layer increases, and the metal film 10 with a resin layer or While sufficiently preventing the flexibility of the manufactured circuit board and the mounting board from being impaired, the strength and the durability can be made particularly excellent, and the heat conductivity of the resin layer 2 is particularly excellent. It can be. Further, the coefficient of thermal expansion of the resin layer 2 can be made particularly low. Such effects are more remarkably exhibited when talc is included among various inorganic fillers.

  The average particle size of the filler is not particularly limited, but is preferably 0.1 μm or more and 50 μm or less.

  In the present specification, the average particle diameter refers to a volume-based average particle diameter unless otherwise specified.

  The particle diameter can be measured by dispersing the target particles in water by ultrasonic treatment for 1 minute using a laser diffraction / scattering particle size distribution analyzer SALD-7000.

  When the resin layer 2 contains a filler, the content of the filler in the resin layer 2 is preferably 5% by mass or more and 80% by mass or less.

  Thereby, while the effect by including the above-described curable resin having an epoxy group or a cured product thereof is surely exhibited, the effect by including a filler is more remarkably exhibited.

  When the resin layer 2 contains an inorganic filler among various fillers, the content of the inorganic filler in the resin layer 2 is preferably from 5% by mass to 65% by mass.

  Thereby, while the effect by including the above-described curable resin having an epoxy group or the cured product thereof is surely exhibited, the effect by including the inorganic filler is more remarkably exhibited.

  In addition, by including a flexible component that does not constitute a part of the cured product, the flexibility / bending resistance of the metal film 10 with the resin layer, the circuit board and the mounting board manufactured using the same, and the heat resistance, etc. Can be adjusted more easily.

  Examples of such a soft component (a soft component that does not constitute a part of the cured product) include various rubbers such as acrylic rubber and nitrile rubber (NBR), rubber-modified polyamide, and acrylic thermoplastic elastomer. Thermoplastic elastomers and the like can be mentioned.

  The carboxylic acid-modified ethylene acrylic rubber has, for example, a partial structure represented by the following formula (1), the following formula (2) or the following formula (3).

  In the resin layer 2, the content of the flexible component (the component included as a component of the cured product and the component included as a component not constituting the cured product) is 20% by mass or more. It is preferably 60% by mass or less, more preferably 23% by mass or more and 55% by mass or less.

  Thereby, the flexibility and bendability can be particularly excellent while the durability and the like of the metal film 10 with the resin layer and the circuit board and the mounting board manufactured using the same are sufficiently improved. .

  As the composition used for forming the resin layer 2 (composition for forming a layer), other components may be used in addition to the aforementioned components (curable resin, filler, flexible component, and the like).

  Examples of such components include a curing agent, a coupling agent, various solvents, an antifoaming agent, a leveling agent, and the like.

  By using the curing agent, the curing reaction of the curable resin can be rapidly advanced under relatively mild conditions, and the formation efficiency of the resin layer 2 and the productivity of the metal film 10 with the resin layer are particularly excellent. It can be.

  Further, by using the coupling agent, the adhesion between the metal film 1 and the resin layer 2 and the durability and reliability of the metal film 10 with the resin layer, the circuit board manufactured using the same, and the mounting board are particularly excellent. It can be.

  Examples of the curing agent include organic metal salts such as zinc naphthenate, cobalt naphthenate, tin octylate, cobalt octylate, bisacetylacetonatocobalt (II), and trisacetylacetonatocobalt (III); dicyandiamide, diethylenetriamine, Amine curing such as triethylenetetramine, metaxylylenediamine, diaminodiphenylmethane, diaminodiethyldiphenylmethane, metaphenylenediamine, diaminodiphenylsulfone, isophoronediamine, norbornenediamine, triethylamine, tributylamine, diazabicyclo [2,2,2] octane, etc. 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-imidazole, 2-phenyl-4-methylimidazole, 2-ethyl- Imidazole-based curing agents such as -methylimidazole, 2-ethyl-4-ethylimidazole, 2-phenyl-4-methyl-5-hydroxyimidazole, 2-phenyl-4,5-dihydroxyimidazole; triphenylphosphine, tri-p -Organic phosphorus compounds such as tolylphosphine, tetraphenylphosphonium tetraphenylborate, triphenylphosphine triphenylborane, 1,2-bis- (diphenylphosphino) ethane; phenol compounds such as phenol, bisphenol A and nonylphenol; acetic acid And organic acids such as benzoic acid, salicylic acid, and paratoluenesulfonic acid, and derivatives thereof. As the curing agent, one selected from these may be used alone, or two or more of these may be used in combination.

  Among these, an amine-based curing agent and an imidazole-based curing agent are preferable in that a cured product having excellent adhesiveness, reacting at a relatively low temperature, and having excellent heat resistance can be obtained.

  As the coupling agent, for example, various materials known as coupling agents can be used. Specifically, epoxy silane coupling agents, cationic silane coupling agents, amino silane coupling agents, titanate-based coupling agents It is preferable to use one or more coupling agents selected from a coupling agent and a silicone oil type coupling agent.

  Examples of the solvent include acetone, methyl ethyl ketone, toluene, xylene, n-hexane, methanol, ethanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methoxypropanol, cyclohexanone, N-methylpyrrolidone, dimethylformamide, dimethylacetamide and the like. be able to.

The tensile storage modulus at 100 ° C. of the resin layer 2 in a state where the curable resin is cured is preferably 1 MPa or more, more preferably 2 MPa or more and 40 MPa or less, and 4 MPa or more and 35 MPa or less. More preferred.
Thereby, the heat resistance of the resin layer 2 can be further improved.

  The value of the tensile storage elastic modulus can be determined by measurement in accordance with JIS K7244-4 (ISO 6721). More specifically, for example, a dynamic viscoelasticity automatic measuring device is used to measure the temperature from -100 ° C to 200 ° C. The temperature can be raised at a constant rate of 1 ° C./min to a temperature of 10 ° C. at a frequency of 10 Hz.

The volume resistivity of the resin layer 2 is preferably 1 × 10 ¹³ Ω · cm or more, and more preferably 1 × 10 ¹⁵ Ω · cm or more and 1 × 10 ¹⁶ Ω · cm or less.
Thereby, the insulation of the resin layer 2 can be made sufficiently excellent.

  The thickness of the resin layer 2 is not particularly limited, but is preferably 10 μm or more and 1000 μm or less, and more preferably 20 μm or more and 300 μm or less.

  When the thickness of the resin layer 2 is within the above range, the flexibility / bending resistance of the metal film with a resin layer 10, a circuit board manufactured using the same, and a mounting board is ensured while ensuring sufficient insulation. Can be made particularly excellent. In addition, the overall heat dissipation of the metal film with a resin layer 10 can be made particularly excellent, and the generation of thermal stress due to the difference in the coefficient of thermal expansion between the metal film 1 and the resin layer 2 can be more effectively reduced. Thus, the adhesion between the metal film 1 and the resin layer 2 and the durability of the metal film 10 with the resin layer and the circuit board and the mounting board manufactured using the same can be made particularly excellent.

  The resin layer 2 may have a uniform composition at each portion or may have portions having different compositions. For example, the resin layer 2 may be a laminate having a plurality of layers having different compositions, or may be formed of a gradient material whose composition changes in a gradient direction in the thickness direction.

The metal film with a resin layer 10 satisfies the following conditions.
That is, the metal film 10 with a resin layer has a warp rate of 5% or less measured by the method described in JIS-C-6471 in a state where the curable resin constituting the resin layer 2 is cured (C stage). is there.

  This effectively prevents undesired warpage (curl) of the metal film with a resin layer 10 or a circuit board manufactured using the metal film with a resin layer 10, has high flatness, and mounts electronic components and the like. In this case, workability can be improved.

  On the other hand, if the warpage rate of the metal film with a resin layer 10 is too large, undesired warpage is likely to occur on the metal film with a resin layer 10 or on a circuit board manufactured using the metal film with a resin layer 10, and electronic components The workability when mounting the components and the like is sharply reduced, and the handling of the metal film 10 with the resin layer and the circuit board (handling property) and the productivity of the mounting board are significantly reduced.

The warpage ratio of the metal film with a resin layer 10 measured by the method described in JIS-C-6471 may be 5% or less, but is preferably 4% or less, more preferably 3% or less. preferable.
Thereby, the above-mentioned effects are more remarkably exhibited.

  In the case where the resin layer 2 contains a B-stage resin material, the curing of the B-stage resin material during the measurement of the warp rate of the metal film with a resin layer 10 (the same applies to the above-described measurement of the tensile storage modulus). For example, it can be performed by a heat treatment at 195 ° C. × 1 to 2 hours.

≪Circuit board≫
Next, a circuit board manufactured using the above-described metal film with a resin layer of the present invention will be described.

  The metal film 10 with a resin layer as described above is used as a circuit board by forming a circuit by forming the metal film 1 into a predetermined pattern by etching or the like. A multilayer circuit board can be obtained by laminating and using the metal film with a resin layer 10 (the metal film with a resin layer 10 in which the metal film 1 has a predetermined pattern by etching or the like). In this case, a multilayer circuit board may be manufactured by interposing an insulating sheet between the metal films 10 with resin layers.

  By satisfying the above-mentioned conditions, the circuit board is effectively prevented from being undesirably warped, and is excellent in workability when mounting electronic components and the like. Therefore, the productivity of the mounting substrate can be improved.

≪Mounting board≫
Next, the mounting board of the present invention will be described.

FIG. 2 is a sectional view schematically showing a preferred embodiment of the mounting board of the present invention.
The mounting board 100 is one in which the electronic component 60 is mounted on the circuit board 50 (having a circuit obtained by patterning the metal film 1 of the metal film 10 with a resin layer) as described above.

  Since such a mounting board 100 is manufactured by using the metal film 10 with a resin layer as described above, it is inexpensive, has sufficient bending resistance and heat resistance, and prevents occurrence of undesired warpage. It was done.

  In the manufacture of the mounting substrate 100, for example, a solder resist may be formed on the outermost layer, and the connection electrode portion may be exposed by exposure and development so that the electronic component 60 can be mounted.

  The mounting board 100 has a thermal conductivity such as Al on the resin layer (insulating layer) 2 side of the circuit board 50 (for example, a portion that overlaps with a heat-generating component when the mounting board 100 is viewed in a plan view). A heat radiation member (not shown) made of a material may be provided.

  As described above, the preferred embodiments of the present invention have been described, but the present invention is not limited to these, and modifications, improvements, etc. within a range that can achieve the object of the present invention are included in the present invention. .

  For example, the metal film with a resin layer of the present invention includes a metal plate functioning as a heat dissipation layer in addition to the metal film (metal film for forming a circuit) and the resin layer (resin layer functioning as an insulating layer) as described above. Things.

  Further, in the above-described embodiment, the case where the circuit board is obtained by processing the metal film with the resin layer (by patterning the metal film of the metal film with the resin layer) is typically described. When manufacturing the metal film with a resin, a metal film with a predetermined pattern may be obtained by forming a metal film on the resin layer using a mask with a predetermined pattern. In other words, the metal film with a resin layer may be used as it is as a circuit board.

  Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

[1] Preparation of composition for forming resin layer (Preparation Example 1)
Bisphenol A type phenoxy resin (YP-55U, Nippon Steel & Sumitomo Metal Corporation, weight average molecular weight 4.2 × 10 ⁴ , epoxy equivalent: 21000): 50.2 parts by mass, modified liquid epoxy resin as a flexible component (Mitsubishi Chemical Corporation) Manufactured by YX7105, epoxy equivalent: 487): 29.0 parts by mass, 2-phenyl-4,5-dihydroxymethylimidazole (manufactured by Shikoku Chemicals): 0.1 part by mass as a curing catalyst, dicyandiamide (Degussa) as a curing agent 0.6 parts by mass), 20.1 parts by mass of talc (average particle diameter: 18 μm, manufactured by Fuji Talc Kogyo Co., Ltd., PKP-53) were dissolved and mixed in cyclohexanone, dimethylformamide, and methyl ethyl ketone, and a high-speed stirrer was used. The mixture was stirred to obtain a varnish-like resin layer-forming composition having a nonvolatile content of 64% by mass.

(Preparation Example 2)
Bisphenol A type phenoxy resin (YP-55U, manufactured by Nippon Steel & Sumitomo Metal Corporation, weight average molecular weight 4.2 × 10 ⁴ , epoxy equivalent: 21000): 41.3 parts by mass, low elasticity liquid epoxy resin as a flexible component (Asahi Kasei AER9000, epoxy equivalent: 380): 26.8 parts by mass, liquid phenol novolak (MEH-8005, hydroxyl equivalent: 135): 9.5 parts by mass, 2-phenyl as a curing catalyst 2.6 parts by mass of -4,5-dihydroxymethylimidazole (manufactured by Shikoku Chemicals), 19.8 parts by mass of talc (average particle diameter: 18 μm, manufactured by Fuji Talc, PKP-53): 19.8 parts by mass are dissolved in cyclohexanone and methyl ethyl ketone. -Mix and stir using a high-speed stirrer to form a varnish-like resin layer with a non-volatile content of 70% by mass. It was obtained Narubutsu.

(Preparation Example 3)
Bisphenol A type phenoxy resin (Nippon Steel & Sumitomo Metal Chemical, YP-55U, weight average molecular weight 4.2 × 10 ⁴ , epoxy equivalent: 21000): 62.7 parts by mass, modified liquid epoxy resin as a flexible component (Mitsubishi Chemical) , YX7105, epoxy equivalent: 487): 36.3 parts by mass, 2-phenyl-4,5-dihydroxymethylimidazole (manufactured by Shikoku Chemicals): 0.2 parts by mass as a curing catalyst, dicyandiamide (Degussa) as a curing agent 0.8 parts by mass were dissolved and mixed in cyclohexanone and methyl ethyl ketone, and stirred using a high-speed stirrer to obtain a varnish-like resin layer-forming composition having a nonvolatile component content of 55% by mass.

(Preparation Example 4)
Bisphenol A type phenoxy resin (Nippon Steel & Sumitomo Metal Corporation, YP-55U, weight average molecular weight 4.2 × 10 ⁴ , epoxy equivalent: 21000): 55.0 parts by mass, low elasticity liquid epoxy resin as a flexible component (Asahi Kasei) AER9000, epoxy equivalent: 380): 31.1 parts by mass, liquid phenol novolak (MEH-8005, hydroxyl equivalent: 135) manufactured by E-materials: 11.1 parts by mass, 2-phenyl as a curing catalyst -4,5-dihydroxymethylimidazole (manufactured by Shikoku Chemicals): 2.8 parts by mass are dissolved and mixed in cyclohexanone and methyl ethyl ketone, and stirred using a high-speed stirrer to form a varnish having a nonvolatile component content of 60% by mass. Thus, a composition for forming a resin layer was obtained.

(Preparation Example 5)
Bisphenol A type phenoxy resin (Nippon Steel & Sumitomo Metal Corporation, YP-55U, weight average molecular weight 4.2 × 10 ⁴ , epoxy equivalent: 21000): 63.6 parts by mass, silicone resin (XE14-A0425 manufactured by Momentive Performers) A), 8.5 parts by mass of a polyalkylalkenylsiloxane), 8.5 parts by mass of a silicone resin (XE14-A0425 (B), polyalkylhydrogensiloxane manufactured by Momentive Performances), modified liquid epoxy resin as a flexible component ( Mitsubishi Chemical, YX7105, epoxy equivalent: 487): 18.9 parts by mass, 2-phenyl-4,5-dihydroxymethylimidazole as a curing catalyst (manufactured by Shikoku Chemicals): 0.1 parts by mass, dicyandiamide as a curing agent (Manufactured by Degussa): 0.4 parts by mass of cyclohexanone, dimethyl It was dissolved and mixed in formamide and methyl ethyl ketone, and stirred using a high-speed stirrer to obtain a varnish-like resin layer-forming composition having a nonvolatile content of 55% by mass.

(Preparation Example 6)
Bisphenol A type phenoxy resin (manufactured by Nippon Steel & Sumitomo Metal Chemical, YP-55U, weight average molecular weight 4.2 × 10 ⁴ , epoxy equivalent: 21000): 49.8 parts by mass, bisphenol F type epoxy resin (manufactured by DIC, 830S, Epoxy equivalent: 170): 26.8 parts by mass, 2-phenyl-4,5-dihydroxymethylimidazole as a curing catalyst (manufactured by Shikoku Chemicals): 0.4 parts by mass, dicyandiamide as a curing agent (manufactured by Degussa): 1 0.5 parts by mass, 21.5 parts by mass of talc (average particle diameter: 18 μm, manufactured by Fujitalc Industries, PKP-53): dissolved and mixed in cyclohexanone, dimethylformamide, and methyl ethyl ketone, and stirred using a high-speed stirrer. Thus, a varnish-like resin layer-forming composition having a nonvolatile component content of 61% by mass was obtained.

(Preparation Example 7)
Bisphenol A type phenoxy resin (Nippon Steel & Sumitomo Metal Corporation, YP-55U, weight average molecular weight 4.2 × 10 ⁴ , epoxy equivalent: 21000): 87.8 parts by mass, low elasticity liquid epoxy resin as a flexible component (Asahi Kasei E-Materials, AER9000, epoxy equivalent: 380): 8.6 parts by mass, liquid phenol novolak (MEH-8005, hydroxyl equivalent: 135): 2.9 parts by mass, 2-phenyl as curing catalyst -4,5-dihydroxymethylimidazole (manufactured by Shikoku Chemicals): 0.7 part by mass is dissolved and mixed in cyclohexanone and methyl ethyl ketone, and the mixture is stirred using a high-speed stirrer to give a varnish having a nonvolatile component content of 38% by mass. Thus, a composition for forming a resin layer was obtained.

(Preparation Example 8)
Modified liquid epoxy resin as a flexible component (YX7105, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: 487): 97.4 parts by mass, 2-phenyl-4,5-dihydroxymethylimidazole (manufactured by Shikoku Chemicals) as a curing catalyst: 0. 5 parts by mass, 2.1 parts by mass of dicyandiamide (manufactured by Degussa) as a curing agent were dissolved and mixed in methyl ethyl ketone and dimethylformamide, and stirred using a high-speed stirrer to give a varnish having a nonvolatile component content of 98% by mass. A resin composition for forming a resin layer was obtained.

(Preparation Example 9)
Bisphenol A type phenoxy resin (Nippon Steel & Sumitomo Metal Chemical, YP-55U, weight average molecular weight 4.2 × 10 ⁴ , epoxy equivalent: 21000): 17.1 parts by mass, modified liquid epoxy resin as a flexible component (Mitsubishi Chemical) , YX7105, epoxy equivalent: 487): 11.3 parts by mass, 2-phenyl-4,5-dihydroxymethylimidazole (manufactured by Shikoku Chemicals): 0.1 part by mass as a curing catalyst, dicyandiamide (Degussa) as a curing agent ): 0.3 parts by mass, talc (average particle size: 18 μm, manufactured by Fuji Talc Kogyo Co., Ltd., PKP-53): 71.3 parts by mass are dissolved and mixed in cyclohexanone, dimethylformamide, and methyl ethyl ketone, and a high-speed stirrer is used. The mixture was stirred to obtain a varnish-like resin layer-forming composition having a nonvolatile content of 87% by mass.

[2] Production of metal film with resin layer (Examples 1 to 5)
Using the varnish-like resin layer-forming compositions obtained in Preparation Examples 1 to 5, metal films with a resin layer were produced as follows.

First, a copper foil having a thickness of 35 μm was prepared.
The composition for forming a resin layer was applied to the surface of the copper foil using a die coater, and heated to 120 ° C. to remove the solvent.

  Thereafter, the composition is heated at 195 ° C. for 1.5 hours to cure the resin layer forming composition, form a resin layer made of a material containing a C-stage resin material (cured product), and form a metal film with a resin layer. Obtained.

(Examples 6 to 10)
Using the varnish-like resin layer-forming compositions obtained in Preparation Examples 1 to 5, metal films with a resin layer were produced as follows.

First, a copper foil having a thickness of 35 μm was prepared.
On the surface of the copper foil, a resin layer-forming composition is applied by a die coater, heated to 120 ° C., the solvent is removed, and a resin layer made of a material including a B-stage resin material is formed. A metal film with a resin layer was obtained.

(Comparative Examples 1-4)
A metal film with a resin layer was obtained in the same manner as in Example 1 except that the compositions prepared in Preparation Examples 6 to 9 were used as the resin layer forming compositions.

(Comparative Examples 5 to 8)
A metal film with a resin layer was obtained in the same manner as in Example 6 except that the compositions prepared in Preparation Examples 6 to 9 were used as the resin layer forming compositions.

  With respect to the metal films with a resin layer of the above Examples and Comparative Examples, the composition for forming the resin layer used in the production, the flexural modulus of the resin layer measured according to ASTM-D-790, and the flexural modulus according to ASTM-D-882 Table 1 shows the tensile elongation (elongation at break) of the resin layer measured by the above method and the warpage rate measured by the method described in JIS-C-6471. In Examples 6 to 10 and Comparative Examples 5 to 8, the heat treatment at 195 ° C. for 1.5 hours was performed on the metal film with a resin layer manufactured as described above to completely cure the curable resin. After the measurement, the value of the warpage ratio was determined.

  In addition, Table 1 shows a dynamic viscoelasticity automatic measuring device based on the value of the tensile storage modulus at 100 ° C. of the resin layer in a state where the curable resin is cured (JIS K7244-4 (ISO 6721)). Using (DMS6100 (manufactured by SII NanoTechnology)), the temperature was raised from -100 ° C to 200 ° C at a constant rate of 1 ° C / minute at a frequency of 10 Hz. In Examples 6 to 10 and Comparative Examples 5 to 8, the metal film with the resin layer manufactured as described above was subjected to a heat treatment at 195 ° C. × 1.5 hours to completely cure the curable resin. The value of the tensile storage modulus was determined by a subsequent measurement.

  The measurement of the flexural modulus, tensile elongation (elongation at break), and tensile storage modulus was performed on a sample obtained by removing a metal film (copper foil) from a metal film with a resin layer by etching. Tensilon (manufactured by Yamato Scientific Co., Ltd.) was used to measure the flexural modulus, and Tensilon (manufactured by Yamato Scientific Co., Ltd.) was used to measure the tensile elongation (elongation at break).

[3] Evaluation [3.1] Heat resistance After cutting the metal film with a resin layer according to each of the examples and the comparative examples manufactured in the above [2] into a size of 50 mm × 50 mm by a press cutter, Based on JIS C 6481, the state of the metal film with the resin layer when floated in a solder bath at 260 ° C. for 120 seconds was visually observed and evaluated according to the following evaluation criteria.

：: No abnormality such as swelling or peeling.
×: Abnormalities such as swelling and peeling are observed.

[3.2] Flex resistance The metal film with a resin layer according to each of the examples and the comparative examples manufactured in the above [2] is cut into a size of 100 mm x 25 mm by a press cutter, and then the resin layer is placed outside. The vicinity of the center was pressed against a round bar of R = 0.5 mm and bent at 90 °. The state of the bent portion was visually observed and evaluated according to the following criteria.

A: No crack in the resin layer is observed at the bent portion.
B: Cracks in the resin layer are hardly observed at the bent portion.
C: At the bent portion, slight cracks in the resin layer are slightly observed.
D: At the bent portion, although small cracks in the resin layer are observed, no large cracks (length: 2 mm or more) are observed.
E: At the bent portion, large cracks (length: 2 mm or more) or peeling of the resin layer are clearly observed.

[3.3] Repetitive bending resistance The metal films with a resin layer according to each of the examples and the comparative examples manufactured in the above [2] were cut into a size of 100 mm x 25 mm by a press cutter. Next, after bending the resin layer to 90 ° at R = 5.0 mm with the resin layer on the outside, the operation of bending the resin layer to 90 ° at R = 5.0 mm with the resin layer on the inside is repeated, and visual observation is performed. Then, the number of times of the above operation until a crack having a length of 1.0 mm or more was generated in the resin layer was obtained, and evaluated according to the following criteria.

A: Even after the above operation was performed four times, no crack having a length of 1.0 mm or more was generated.
B: When the above operation was performed four times, cracks having a length of 1.0 mm or more occurred.
C: When the above operation was performed three times, cracks having a length of 1.0 mm or more occurred.
D: When the above operation was performed twice, cracks having a length of 1.0 mm or more occurred.
E: When the above operation was performed once, cracks having a length of 1.0 mm or more were generated.

[3.4] Conductor Adhesion Force The metal films with a resin layer according to each of the examples and the comparative examples manufactured in the above [2] were cut into a size of 100 mm × 25 mm by a press cutter. Next, after etching so as to leave a metal film of 100 mm × 10 mm, the peel strength was evaluated by a 90 ° peel test based on JIS C 6481 according to the following criteria.

A: The peel strength was 2.0 kN / m or more.
B: Peel strength was 1.5 kN / m or more and less than 2.0 kN / m.
C: Peel strength was 1.0 kN / m or more and less than 1.5 kN / m.
D: The peel strength was 0.5 kN / m or more and less than 1.0 kN / m.
E: Peel strength was less than 0.5 kN / m.

[3.5] Insulation evaluation After cutting the metal film with resin layer according to each of the examples and the comparative examples manufactured in the above [2] into a size of 100 mm x 100 mm with a press cutter, the metal film ( The copper foil was removed by etching to produce a sample. Using a withstand voltage tester (MODEL7473, manufactured by EXTECH Electronics), an electrode is brought into contact with the resin layer and the aluminum plate, and an AC voltage is applied to both electrodes so that the voltage increases at a rate of 0.5 kV / sec. did. The voltage at which the resin layer of the metal film with the resin layer was broken was divided by the thickness of the resin layer to obtain a dielectric breakdown voltage (kW / mm) per unit thickness (mm), which was evaluated according to the following criteria. It can be said that the larger the dielectric breakdown voltage is, the more excellent the insulating property is.

A: The dielectric breakdown voltage was 50 kW / mm or more.
B: The dielectric breakdown voltage was 40 kW / mm or more and less than 50 kW / mm.
C: The dielectric breakdown voltage was 30 kW / mm or more and less than 40 kW / mm.
D: The dielectric breakdown voltage was 20 kW / mm or more and less than 30 kW / mm.
E: The dielectric breakdown voltage was less than 20 kW / mm.

[3.6] Evaluation of insulation properties after bending The metal films with a resin layer according to each of the examples and the comparative examples manufactured in the above [2] were cut into a size of 100 mm x 100 mm by a press cutter, respectively. With the resin layer on the outside, the center was pressed against a round bar of R = 3.0 mm and bent at 90 °. Next, after a roller was pressed against the metal film to form a flat plate, the metal film (copper foil) was removed by etching to prepare a sample. Using a withstand voltage tester (MODEL7473, manufactured by EXTECH Electronics), an electrode is brought into contact with the resin layer and the aluminum plate, and an AC voltage is applied to both electrodes so that the voltage increases at a rate of 0.5 kV / sec. did. The voltage at which the resin layer of the metal film with the resin layer was broken was divided by the thickness of the resin layer to obtain a dielectric breakdown voltage (kW / mm) per unit thickness (mm), which was evaluated according to the following criteria.

A: The dielectric breakdown voltage was 50 kW / mm or more.
B: The dielectric breakdown voltage was 40 kW / mm or more and less than 50 kW / mm.
C: The dielectric breakdown voltage was 30 kW / mm or more and less than 40 kW / mm.
D: The dielectric breakdown voltage was 20 kW / mm or more and less than 30 kW / mm.
E: The dielectric breakdown voltage was less than 20 kW / mm.

[3.7] Ease of mounting electronic components on a circuit board (warpage workability)
After cutting the metal film with the resin layer according to each of the examples and the comparative examples manufactured in the above [2] into a size of 100 mm × 100 mm by a press cutter, a dry film type etching resist is formed on the metal film surface. After laminating, exposing and developing, the metal film was processed into a predetermined pattern by a subtractive method using a ferric chloride-based copper etching solution to produce a circuit, and a circuit board was obtained.

The workability (easiness of mounting the electronic component on the circuit board) when mounting an LED element (LVYE67F manufactured by OSRAM) as an electronic component on the circuit board thus obtained was evaluated, and the circuit board ( Good for workability (easiness of mounting electronic components on a circuit board) with unintended warpage of the resin film (metal film with resin layer) prevented, and unwilling for the circuit board (metal film with resin layer) A sample having poor warpage and poor workability (easiness of mounting electronic components on a circuit board) was evaluated as x.
The results are shown in Table 2.

In the present invention (each embodiment), the heat resistance was sufficient, the bending resistance was excellent, and the occurrence of undesired warpage was prevented. Further, in the present invention (each example), the adhesion between the metal film and the resin layer is excellent, and the resin layer has a sufficient insulating property. Further, in the present invention (each example), the volume resistivity of the resin layer was a value within the range of 1 × 10 ¹⁵ Ω · cm to 1 × 10 ¹⁶ Ω · cm. In the present invention (each example), the glass transition temperature of the cured product of the curable resin in the state where the curable resin constituting the resin layer is cured is in the range of 130 ° C. or more and 250 ° C. or less. Value.
On the other hand, in the comparative example, a satisfactory result was not obtained.

  In addition, the same evaluations as in the above [3.1] to [3.6] were performed on the mounting boards of the examples and the comparative examples manufactured in the above [3.7]. The same result as the result of the metal film with the resin layer) was obtained.

10: metal film with resin layer 1: metal film 2: resin layer (insulating layer)
50: circuit board 60: electronic component 100: mounting board

Claims (12)

A metal film,
A resin layer made of a material containing a cured product of a curable resin having an epoxy group,
The flexural modulus of the resin layer measured according to ASTM-D-790 is 10 MPa or more;
The resin layer has a tensile elongation (elongation at break) of 3% or more measured according to ASTM-D-882,
The warpage rate measured by the method described in JIS-C-6471 is 5% or less,
The cured product obtained by curing the curable resin is a phenoxy resin having an epoxy equivalent of 5,000 or more and a polyfunctional epoxy compound reacted with the phenoxy resin. A metal film,
With a resin layer made of a material containing a curable resin having an epoxy group,
The flexural modulus of the resin layer measured according to ASTM-D-790 is 10 MPa or more;
The resin layer has a tensile elongation (elongation at break) of 3% or more measured according to ASTM-D-882,
Wherein Ri der warp ratio is less than 5% as measured by JIS-C-6471 according to the method described in a state where the curable resin is cured,
The cured product curable resin is cured, the epoxy equivalent is 5,000 or more phenoxy resins, polyfunctional epoxy compound, characterized in der Rukoto that reacts with a resin layer metal film.   The metal film with a resin layer according to claim 1, wherein the resin layer contains a flexible component.   4. The flexible component according to claim 3, wherein the flexible component reacts with the curable resin by a functional group capable of reacting with the curable resin, and forms a part of a molecule of a cured product in the resin layer. Metal film with resin layer.   5. The metal film with a resin layer according to claim 3, wherein a content of the flexible component in the resin layer is 20% by mass or more and 60% by mass or less.   The metal film with a resin layer according to any one of claims 1 to 5, wherein the resin layer contains 5 to 65 parts by mass of an inorganic filler.   The metal film with a resin layer according to any one of claims 1 to 6, wherein a tensile storage modulus at 100 ° C of the resin layer in a state where the curable resin is cured is 1 MPa or more.   The metal film with a resin layer according to any one of claims 1 to 7, wherein an epoxy equivalent of the curable resin is 100 or more. 9. The metal film with a resin layer according to claim 1, wherein the volume resistivity of the resin layer is 1 × 10 ¹³ Ω · cm or more. 10.   The metal film with a resin layer according to claim 1, wherein the thickness of the resin layer is 10 μm or more and 1000 μm or less.   The metal film with a resin layer according to claim 1, wherein the thickness of the metal film is 5 μm or more and 1000 μm or less.   A mounting board obtained by mounting an electronic component using the metal film with a resin layer according to any one of claims 1 to 11.

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