JPWO2018193757A1 - Aluminum base copper clad laminate - Google Patents

Abstract

An electrically insulating insulating resin layer having a thickness of 60 to 140 μm, an aluminum plate having a thickness of 0.5 to 2.0 mm laminated on one surface of the insulating resin layer, and an aluminum plate having a thickness of 0.5 to 2.0 mm laminated on the other surface of the insulating resin layer And a copper foil having a thickness of 18 to 105 μm and a length of 100 mm and a width of 25 mm. An aluminum-based copper-clad laminate having a 0.2% proof stress of 200 to 295 MPa when subjected to a three-point bending test in which a load is applied from the copper foil side.

Description

  The present invention relates to an aluminum-based copper-clad laminate.

  The technology relating to a laminate (hereinafter also referred to as an aluminum-based copper-clad laminate, or simply a laminate) having a copper foil layer, an insulating layer, and the like based on an aluminum plate is known in various technical fields, for example, electric fields. -Considered in the field of electronics, lighting, and the like (for example, see Patent Document 1).

JP 2005-281509 A

  However, according to the study of the present inventors, conventional aluminum-based copper-clad laminates have insufficient strength, and when used as, for example, electric / electronic parts, cracks occur in the insulating layer or copper foil due to external force. There was an easy problem and there was room for improvement.

  The present inventor has conducted intensive studies in order to achieve the above object, and has found that an aluminum-based copper-clad laminate having a specific structure can solve the above object.

That is, according to the present invention,
An aluminum-based copper-clad laminate,
An electrically insulating insulating resin layer having a thickness of 60 to 140 μm;
An aluminum plate having a thickness of 0.5 to 2.0 mm laminated on one surface of the insulating resin layer,
A copper foil having a thickness of 18 to 105 μm laminated on the other surface of the insulating resin layer,
When the aluminum base copper-clad laminate having a length of 100 mm and a width of 25 mm was subjected to a three-point bending test in which a load was applied from the copper foil side under a condition of a fulcrum distance of 64 mm and a bending speed of 10 mm / min, An aluminum-based copper-clad laminate having a 0.2% proof stress of 200-295 MPa is provided.

  According to the present invention, there is provided an aluminum-based copper-clad laminate having improved strength against physical impact. More specifically, the present invention provides an aluminum-based copper-clad laminate in which the occurrence of cracks against impact (external force) is suppressed.

  The above and other objects, features and advantages will become more apparent from the preferred embodiments described below and the accompanying drawings.

It is the figure which represented typically the aluminum base copper clad laminated board which concerns on embodiment of this invention. It is a figure explaining how to ask for "proof stress". It is the figure which represented typically the manufacturing process of the aluminum base copper clad laminated board which concerns on embodiment of this invention. It is the figure which represented typically a part of manufacturing process of the aluminum base copper clad laminated board concerning the embodiment of the present invention.

  Hereinafter, embodiments of the aluminum-based copper-clad laminate of the present invention will be described in detail with reference to the drawings. In the description, as described above, the aluminum-based copper-clad laminate is also simply referred to as a laminate. In all the drawings, the same components are denoted by the same reference numerals, and description thereof will not be repeated. Also, the dimensional ratios in the drawings do not always correspond to actual articles and may be exaggerated. Further, the description “ab” in the numerical range represents a or more and b or less unless otherwise specified.

<Aluminum-based copper-clad laminate>
FIG. 1 shows a cross section of an aluminum-based copper-clad laminate 10 according to the present embodiment. The laminated plate 10 includes an electrically insulating insulating resin layer 11 having a thickness of 60 to 140 μm, an aluminum plate 12 having a thickness of 0.5 to 2.0 mm laminated on one surface of the insulating resin layer 11, And a copper foil 13 having a thickness of 18 to 105 μm laminated on the other surface of the resin layer 11. The laminate 10 according to the present embodiment is a three-point bend that applies a load from the copper foil 13 side under the conditions of a distance between fulcrums of 64 mm and a bending speed of 10 mm / min for the laminate 10 having a length of 100 mm and a width of 25 mm. When the test is performed, the aluminum-based copper-clad laminate 10 has a 0.2% proof stress of 200 to 295 MPa.

  “Proof strength” is an index generally indicating the strength of a material whose yield point is not clear to plastic deformation. The “X% proof stress” in the present specification refers to a tangent OE to an elastic deformation region (a region where load and displacement are directly proportional) of the stress-strain curve in the three-point bending test, and a strain X parallel to the tangent OE. When the parallel line AF offset by% is drawn and the intersection C between the parallel line AF and the stress-strain curve is obtained, the load P at the intersection C is the X% proof stress (see FIG. 2).

  As described above, in the conventional laminated plate, cracks easily occur in the insulating layer and the copper foil due to external force. Therefore, the present inventor has conducted a three-point bending test on the entire laminated board 10 under the conditions described in the present specification while making each of the insulating resin layer 11, the aluminum plate 12, and the copper foil 13 an appropriate thickness as a result of trial and error. 0.2% proof stress of 200 to 295 MPa (preferably 205 to 280 MPa, more preferably 210 to 265 MPa). And it discovered that cracking of the insulating resin layer 11 and the copper foil 13 was effectively suppressed by doing in this way.

  The reason for this is not necessarily clear, but is presumed as follows. In other words, in the three-point bending test, which is a test that simulates various external forces applied when mounting the laminated plate 10, by designing the laminated plate 10 so as to satisfy the above parameters, the entire laminated plate 10 is appropriately plastically deformed. Then, the external force is moderately absorbed without being concentrated at one point. As a result, it is assumed that cracks in the insulating resin layer 11 and the copper foil 13 can be suppressed. In addition, as a result of suppressing cracks, particularly when the laminated board 10 according to the present embodiment is applied to electric / electronic parts, an effect that sufficient insulation properties can be ensured even when an impact is applied can be expected.

  The laminated plate 10 according to the present embodiment has three points where a load is applied to the laminated plate 10 having a length of 100 mm and a width of 25 mm from the copper foil 13 side under a condition of a distance between fulcrums of 64 mm and a bending speed of 10 mm / min. When the bending test is performed, it is preferable that the laminate 10 has a 0.1% proof stress of 185 to 285 MPa. Note that this value is more preferably 185 to 260 MPa, and further preferably 185 to 255 MPa.

  The laminate 10 according to the present embodiment applies a load to the laminate 10 having a length of 100 mm and a width of 25 mm from the copper foil 13 side under a condition of a distance between fulcrums of 64 mm and a bending speed of 10 mm / min. When the three-point bending test is performed, the laminate 10 preferably has a 0.5% proof stress of 210 to 310 MPa. This value is more preferably from 210 to 285 MPa, further preferably from 215 to 280 MPa.

  Further, the laminate 10 according to the present embodiment applies a load to the laminate 10 having a length of 100 mm and a width of 25 mm from the copper foil 13 side under a condition of a distance between fulcrums of 64 mm and a bending speed of 10 mm / min. When the three-point bending test is performed, it is preferable that the laminate 10 has a stress of 1 to 305 MPa when distorted by 1%. This value is more preferably from 205 to 290 MPa, and even more preferably from 205 to 285 MPa.

  By satisfying these parameters, cracks in the insulating resin layer 11 and the copper foil 13 can be more effectively suppressed against various external forces. The 0.2% proof stress, the 0.1% proof stress, the 0.5% proof stress, the stress when distorted by 1%, and the like are, for example, the characteristics and thickness of the aluminum plate 12 used for the laminate 10 and the insulation. The material constituting the resin layer 11 and its component amount, the thickness of the insulating resin layer 11, the characteristics and thickness of the copper foil 13, and the manufacturing conditions (for example, in step (2) described later) By appropriately setting the conditions for heating and pressurizing, etc., the desired values can be obtained.

  Hereinafter, the insulating resin layer 11, the aluminum plate 12, the copper foil 13, and the like constituting the laminated board 10 according to the present embodiment will be described.

[Insulating resin layer 11]
The laminated board 10 according to the present embodiment includes an electrically insulating insulating resin layer 11 having a thickness of 60 to 140 μm. The thickness is preferably 70 to 130 μm, more preferably 80 to 120 μm. With this thickness, sufficient electrical insulation can be obtained, and it can be expected that cracks in the copper foil 13 and the insulating resin layer 11 are less likely to occur.

  The insulating resin layer 11 has an insulating property. Thereby, the space between the aluminum plate 12 and the copper foil 13 is insulated. The insulating resin layer 11 is typically made of a solidified or cured product formed by solidifying or curing a resin composition. Hereinafter, this resin composition will be described.

  The resin composition usually contains a resin. The resin is not particularly limited, and various resins 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, and polyamides (eg, nylon 6, nylon 46, nylon 66, nylon 610, nylon 612, nylon 612, nylon 11, and nylon 12). , Nylon 6-12, nylon 6-66), liquid crystal polymers such as thermoplastic polyimide and aromatic polyester, polyphenylene oxide, polyphenylene sulfide, polycarbonate, polymethyl methacrylate, polyether, polyether ether ketone, polyetherimide, polyacetal, Styrene, polyolefin, polyvinyl chloride, polyurethane, polyester, polyamide, polybutadiene, trans polyisoprene, fluoro rubber, salt Polyethylene type such as various thermoplastic elastomers, etc. or copolymers with these main, blend, and a polymer alloy or the like. These may be used as a mixture of two or more.

  Examples of the thermosetting resin include a phenoxy resin, 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. These may be used as a mixture of two or more.

  It is preferable to use a thermosetting resin as the resin. More specifically, the resin composition contains at least one resin selected from an epoxy resin and a phenoxy resin, in other words, the formed insulating resin layer 11 is selected from an epoxy resin and a phenoxy resin. Preferably, it contains at least one resin. Thereby, when the insulating resin layer 11 is formed, the fluidity of the resin composition is reduced, and it becomes easy to secure a sufficient thickness of the insulating resin layer 11, so that the insulation reliability can be further improved. Further, the adhesion between the insulating resin layer 11 and the aluminum plate 12 or the copper foil 13 is improved. This can contribute to suppression or prevention of delamination between layers when flattening is performed by press working or the like in the manufacturing process of the laminated board 10.

  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. Further, 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 from 4.0 × 10 ^{4 to} 4.9 × 10 ⁴ . Thereby, the elastic modulus of the insulating resin layer 11 can be reduced, and the laminated board 10 can be made excellent in stress relaxation. For example, when a semiconductor device on which a semiconductor element is mounted is manufactured using the laminated board 10, this semiconductor device can more accurately suppress the occurrence of cracks and the like even under a rapid heating / cooling environment. Become.

  The epoxy resin is not particularly limited as long as it has two or more epoxy groups in one molecule. In the present embodiment, an epoxy resin (A) having at least one of an aromatic ring structure and an alicyclic structure (alicyclic carbon ring structure) is preferable. By using such an epoxy resin (A), the adhesion of the insulating resin layer 11 to the aluminum plate 12 and the copper foil 13 can be further improved.

  Examples of the epoxy resin (A) 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, bisphenol type epoxy resin such as bisphenol Z type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, novolak type epoxy resin such as tetraphenol group ethane type novolak type epoxy resin, biphenyl type epoxy resin, biphenylene Examples thereof include an arylalkylene type epoxy resin such as a phenol aralkyl type epoxy resin having a skeleton, and an epoxy resin such as a naphthalene type epoxy resin. These may be used in combination of two or more.

  The content of the resin is usually 1 to 40% by mass, preferably 2 to 20% by mass, more preferably 4 to 16% by mass, based on the entire non-volatile component of the resin composition. When the content is equal to or more than the lower limit, the stress relaxation property is excellent, and the occurrence of cracks can be suppressed. In addition, when the content is equal to or less than the upper limit, appropriate fluidity is ensured, and thus it is desirable from the viewpoint of the suitability for manufacturing the laminate 10.

  The resin composition may include a curing agent as necessary depending on the type of the resin (for example, when an epoxy resin is included). The curing agent is not particularly limited. For example, amide-based curing agents such as dicyandiamide and aliphatic polyamide, amine-based curing agents such as diaminodiphenylmethane, methanephenylenediamine, ammonia, triethylamine and diethylamine, bisphenol A and bisphenol F Phenolic hardeners such as phenol novolak resin, cresol novolak resin, p-xylene-novolak resin, and acid anhydrides.

  The resin composition may further include a curing catalyst (curing accelerator). Thereby, the curability of the resin composition can be improved. Examples of the curing catalyst include imidazoles, amine catalysts such as 1,8-diazabicyclo (5,4,0) undecene, and phosphorus catalysts such as triphenylphosphine. Among these, imidazoles are preferred. Thereby, in particular, the rapid curing property and the preservability of the resin composition can be sufficiently compatible.

  Examples of imidazoles include 1-benzyl-2-methylimidazole, 1-benzyl-2phenylimidazole, 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 isocyanuric acid addition 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 and the like. Among them, 2-phenyl-4,5-dihydroxymethylimidazole or 2-phenyl-4-methyl-5-hydroxymethylimidazole is preferred. Thereby, the preservability of the resin composition can be particularly improved.

  The content of the curing catalyst is not particularly limited, but is preferably 0.01 to 30% by mass, more preferably 0.05 to 10% by mass, based on the entire nonvolatile components of the resin composition. When the content is equal to or more than the lower limit, the curability of the resin composition becomes more sufficient.On the other hand, by setting the content to be equal to or less than the upper limit, the storage stability of the resin composition can be further improved. it can.

  The resin composition preferably contains a coupling agent. Thereby, the adhesion between the aluminum plate 12 and the copper foil 13 can be further improved. Therefore, when the laminate 10 is subjected to a flattening process or the like, the occurrence of cracks in the insulating resin layer 11 is suppressed, and the separation of the insulating resin layer 11 from the aluminum plate 12 or the copper foil 13 is suppressed. Can be expected.

  Examples of the coupling agent include a silane coupling agent, a titanium coupling agent, and an aluminum coupling agent. Among these, a silane coupling agent is preferable from the viewpoint of availability and ease of handling.

  The silane coupling agent is not particularly limited, and examples thereof include 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-aminopropyltriethoxysilane , N-phenyl-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, bis (3- Triethoxysilylpropyl) tetrasulfane. Two or more of these may be used.

  The content of the coupling agent is not particularly limited, but is preferably 0.01 to 10% by mass, more preferably 0.5 to 10% by mass, based on the entire non-volatile components of the resin composition. When the content is equal to or more than the lower limit, the effect of enhancing the above-mentioned adhesion becomes more sufficient. When the content is equal to or less than the upper limit, outgas and voids in forming the insulating resin layer 11 can be further suppressed.

  The resin composition preferably contains a filler. In the present embodiment, the filler is preferably an inorganic material (inorganic filler). When the resin composition contains such a filler, the thermal conductivity can be improved as compared with the case where the insulating resin layer 11 is formed only of an organic material such as a resin. This is desirable when the laminate 10 according to the present embodiment is applied to the electric / electronic field, the lighting field, and the like.

The inorganic filler is not particularly limited. For example, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, calcium oxide, magnesium oxide, aluminum oxide (alumina, Al ₂ O ₃ ), aluminum nitride, aluminum borate whisker, boron nitride, crystalline silica , Amorphous silica, silicon carbide and the like. These may be used in combination of two or more.

  The inorganic filler is preferably a granular material composed of at least one of aluminum oxide and aluminum nitride, and more preferably a granular material mainly composed of aluminum oxide. Thereby, an inorganic filler having more excellent thermal conductivity and insulating properties can be obtained. Aluminum oxide is also preferable because it has excellent versatility and can be obtained at low cost.

  The inorganic filler preferably has an average primary particle diameter (D50: median diameter) of 1 to 10 μm, more preferably 3 to 7 μm. Thereby, the filling rate of the inorganic filler can be further increased. Therefore, the contact area between the inorganic fillers (primary particles) can be increased, and the thermal conductivity can be further improved. The shape of the inorganic filler is not particularly limited, and may be spherical or irregular. In addition, as one embodiment, a spherical inorganic filler and an amorphous inorganic filler may be used in combination (for example, 30 to 40% by mass of the inorganic filler is a spherical filler, and the rest is amorphous) Etc.). By doing so, the amorphous filler enters the gap between the spherical fillers, and the insulating resin layer 11 tends to be denser. This can contribute to the production under low pressure conditions in the production of the laminate 10 described later.

  The content of the filler is preferably from 60 to 90% by mass, more preferably from 70 to 85% by mass, based on the total amount of the nonvolatile components of the resin composition. By setting the lower limit of the numerical range or more, it can be expected that the thermal conductivity of the insulating resin layer 11 is further improved. When the value is not more than the upper limit of the numerical range, the stress relaxation property is excellent, and the occurrence of cracks can be suppressed.

  The resin composition may contain additives such as a leveling agent (surfactant) and an antifoaming agent in addition to the components described above.

  The resin composition usually contains a solvent. The solvent is typically an organic solvent such as methyl ethyl ketone, acetone, toluene, dimethylformaldehyde and the like. That is, the resin composition is typically a solution in which components such as the resin are dissolved or dispersed in an organic solvent, and is in a varnish form.

  The resin composition can be obtained, for example, by mixing a resin material and a solvent to form a varnish, and further mixing an inorganic filler. 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.

[Aluminum plate 12]
The laminated plate 10 according to the present embodiment includes an aluminum plate 12 having a thickness of 0.5 to 2.0 mm laminated on one surface of the insulating resin layer 11. The thickness is preferably 0.5 to 1.0 mm, more preferably 0.6 to 0.8 mm. With this thickness, both impact resistance and ease of processing can be achieved.

  The aluminum plate 12 according to the present embodiment is preferably made of aluminum having a purity of 98.5 to 100% by mass. More preferably, the purity is 99.5 to 100% by mass. The atoms other than the aluminum atom are not particularly limited, but include, for example, magnesium, calcium, oxygen, silicon and the like. According to the findings of the present inventor, high-purity aluminum is moderately soft. Therefore, when the aluminum plate 12 made of such aluminum is used, the laminated plate 10 that satisfies the desired characteristics according to the present embodiment (for example, the laminated plate 10 whose 0.2% proof stress value is 200 to 295 MPa). ) Is considered to be easy to manufacture.

  From another viewpoint, the tensile strength of the aluminum material constituting the aluminum plate 12 is preferably from 95 to 140 MPa, more preferably from 95 to 120 MPa. In addition, the tensile strength here is calculated | required by method JISZ2241. The inventor surprisingly, when selecting the aluminum plate 12 with reference to the index relating to “tensile”, exhibits excellent performance against various impacts simulated by the “three-point bending test” (that is, due to external force). Cracks and dielectric breakdown can be suppressed). Incidentally, when the purity of the aluminum constituting the aluminum plate 12 is increased as described above, the numerical value of the tensile strength tends to fall within the preferable numerical value range.

[Copper foil 13]
The laminated plate 10 according to the present embodiment includes a copper foil 13 having a thickness of 18 to 105 μm, which is laminated on the other surface of the insulating resin layer 11 (the surface opposite to the surface on which the aluminum plate 12 is located). . This thickness is preferably 18 to 70 μm, more preferably 25 to 45 μm, still more preferably 30 to 40 μm, and particularly preferably 35 μm. With this thickness, cracks and the like are less likely to occur, and a sufficient function as the copper foil 13 (for example, electrical conductivity or thermal conductivity) can be exhibited.

<Production method of aluminum-based copper-clad laminate 10>
The laminated board 10 according to the present embodiment is manufactured by the following methods (1), (2) and (3), for example. Of course, as long as the finally obtained laminate 10 has desired properties such as yield strength, the laminate 10 according to the present embodiment may be manufactured by other methods.

(1) Formation of Insulating Resin Layer 11 on Copper Foil 13 First, a flat copper foil 13 is prepared, and then, as shown in FIG. 11A is formed. The insulating resin layer forming layer 11A is obtained by supplying the above-described resin composition onto the copper foil 13 to form a layer, and then drying the layer. The insulating resin layer-forming layer 11A is to be cured or solidified through the step (2) described later to become the insulating resin layer 11.

  The supply of the resin composition to the copper foil 13 can be performed using, for example, a roll coater, a bar coater, a knife coater, a gravure coater, a die coater, a comma coater, a curtain coater, or the like. In addition, application of the ink jet technology is also conceivable. Among these, it is preferable to use a die coater, a knife coater, and a comma coater. Thereby, the insulating resin layer forming layer 11A having no uniform void and having a uniform thickness, and thus the insulating resin layer 11, can be formed more efficiently.

When applied to the step (1), the resin composition preferably has the following viscosity behavior. That is, when the resin composition is heated from 60 ° C. to a molten state at a temperature rising rate of 3 ° C./min at a frequency of 1 Hz using a dynamic viscoelasticity measuring apparatus, the melt viscosity decreases in the initial stage, After reaching the viscosity, it is preferable to have the property of further increasing and the minimum melt viscosity to be in the range of 1 × 10 ³ Pa · s to 1 × 10 ⁵ Pa · s.

  When the minimum melt viscosity is equal to or more than the above lower limit, separation of the resin and the filler can be suppressed, and a more uniform insulating resin layer 11 can be obtained through the step (2) described later. When the minimum melt viscosity is equal to or less than the upper limit, the adhesion between the insulating resin layer 11 and the copper foil 13 can be further improved. Due to these synergistic effects, the thermal conductivity and insulating properties of the laminate 10 can be further improved.

  The temperature at which the resin composition reaches the minimum melt viscosity is preferably in the range of 60 to 100 ° C, and more preferably in the range of 75 to 90 ° C.

Further, the resin composition preferably has a flow rate of 10 to 60%, more preferably 20 to 50%. The flow rate can be measured according to the following procedure. First, after cutting a copper foil having an insulating resin layer formed of the resin composition of the present embodiment into a predetermined size (50 mm × 50 mm), 5 to 7 sheets are laminated, and the weight is measured. Next, after pressing between hot plates maintaining the internal temperature at 175 ° C. for 5 minutes, the mixture is cooled, the resin that has flowed out is carefully dropped, and the weight is measured again. The flow rate can be obtained by the following equation (I).
Flow rate (%) = (weight before measurement−weight after measurement) / (weight before measurement−weight of copper foil) (I)

  When the resin composition has such a viscosity behavior, when the resin composition is heated and cured to form the insulating resin layer 11, air can be further suppressed from entering the resin composition, and the resin composition The gas dissolved inside can be exhausted sufficiently. As a result, generation of bubbles in the insulating resin layer 11 can be further suppressed, and heat can be reliably transmitted from the copper foil 13 to the insulating resin layer 11. Further, since the generation of bubbles is further suppressed, the insulation reliability of the laminated board 10 can be improved. Further, the adhesion between the copper foil 13 and the insulating resin layer 11 can be improved.

  The resin composition having such a viscosity behavior, for example, the type and amount of the above-described resin material, the type and amount of the inorganic filler, and, when the resin material contains a phenoxy resin, the type and amount It can be obtained by appropriate adjustment.

(2) Lamination Next, an aluminum plate 12 is prepared, and then, as shown in FIG. 3B, the copper foil 13 and the aluminum plate 12 approach each other via the insulating resin layer forming layer 11A. And heat as described above. Thus, the aluminum plate 12 is bonded to the insulating resin layer forming layer 11A (FIG. 3C).

  At this time, the insulating resin layer forming layer 11A is formed under the condition that the insulating resin layer forming layer 11A is cured and the insulating resin layer 11 is formed when the insulating resin layer forming layer 11A shows thermosetting properties. Heated and pressurized. When the insulating resin layer-forming layer 11A exhibits thermoplasticity, it is heated and pressurized under conditions of being melted by heating and heating, and then solidified by cooling.

  The heating and pressurizing conditions are appropriately set depending on the type of the resin composition contained in the insulating resin layer forming layer 11A. The heating temperature is preferably set at about 80 to 200 ° C, more preferably about 170 to 190 ° C. The pressure to be applied is preferably set to about 1 to 12 MPa, more preferably about 3 to 10 MPa. Further, the heating and pressurizing time is preferably about 10 to 90 minutes, and more preferably about 30 to 60 minutes.

  By this heating and pressing, the aluminum plate 12 is joined to the insulating resin layer forming layer 11A, and the insulating resin layer forming layer 11A is cured to form the insulating resin layer 11, and as a result, the insulating resin layer 11 The laminate 10 on which the aluminum plate 12 is bonded is obtained.

  Prior to the bonding of the insulating resin layer forming layer 11A and the aluminum plate 12, a surface treatment such as contacting the bonding surface of the aluminum plate 12 with water at 40 to 80 ° C. for 0.5 to 3 minutes is performed. Is preferably applied. Thereby, the adhesion between the insulating resin layer 11 and the aluminum plate 12 can be further improved.

(3) Flattening process When the laminated plate 10 obtained in the above (2) is cooled, the aluminum plate 12, the insulating resin layer 11, and the copper foil 13 have different coefficients of thermal expansion. Warpage may occur. In that case, it is preferable to perform a flattening process to correct the warpage as an optional step. Thereby, the flat laminated board 10 without warpage is obtained.

  The flattening process can be performed using, for example, a flattening apparatus 100 shown in FIG. The flattening device 100 includes a seamless belt 110 on which the laminated plate 10 is placed, and a transport unit 120 that transports the seamless belt 110.

  The transport means 120 has tensioners (tension rollers) 130, 131, 132, 140, 141, 142, and 143.

  As shown in FIG. 4, in the conveying means 120, the seamless belt 110 having an annular shape in side view is attached to the tensioners 130, 131, 132, 140, 141, 142, and 143, and the tensioners 130, 131, 132, 140 , 141, 142, and 143, the seamless belt 110 is repeatedly sent out along the transport direction.

  Each of the tensioners 130, 131, 132, 140, 141, 142, and 143 has a columnar outer shape, and is made of, for example, a metal material such as stainless steel. Further, these tensioners 130, 131, 132, 140, 141, 142, 143 are arranged such that their rotation axes (center axes) face the same direction and are separated from each other. Further, for example, it is rotatably supported by a frame (not shown) that supports the entire flattening device 100.

  Among the tensioners, the tensioners 140 to 143 are rollers that rotate while the contacting seamless belt 110 is hung. The seamless belt 110 is repeatedly sent out in a loop by changing the transport direction at a position corresponding to a corner of the attached seamless belt 110.

  Further, the tensioners 130 to 132 are arranged between the tensioner 140 and the tensioner 141 in this order. The seamless belt 110 that is in contact with the tensioner 130 and the tensioner 131 so as to penetrate the tensioner 131 and the tensioner 132 is a roller that rotates while being wound around.

  Among the tensioners 130 to 132, the tensioner 130 and the tensioner 132 have their centers arranged along the transport direction. The center of the tensioner 131 is shifted from the center of the tensioner 130 and the center of the tensioner 132 in a direction orthogonal to the transport direction.

  The seamless belt 110 is conveyed between the tensioners 130 to 132 arranged as described above, and at this time, the conveying direction is changed. When the seamless belt 110 is transported between the tensioners 130 to 132, the warped laminate 10 is placed on the seamless belt 110 to correct the warp. As a result, the laminate 10 is flattened.

The diameter of the tensioners 130 to 132 is preferably 2 to 30 cm, more preferably 10 to 20 cm. Further, the distance _{L 1} between the tensioner 130 and the tensioner 131, and the distance _{L 2} between the tensioner 131 and the tensioner 132, each independently, preferably 10 to 50 cm, 15 to 30 cm is more preferable. Furthermore, when viewed tensioner 130-132 from the conveying direction, in a direction perpendicular to the conveying direction, the length _{L 3} of the region where the tensioner 130, 132 and tensioner 131 overlap, preferably 2～8Cm, is 4~6cm More preferred. By setting the size and the like of the tensioners 130 to 132 within these ranges, the warpage generated in the laminated board 10 can be more reliably corrected.

  A motor (not shown) is connected to at least one of the tensioners 130 to 132, and the seamless belt 110 is conveyed by the operation of the motor.

  In the laminated board 10 in which the warpage has been corrected, the warpage rate of the aluminum plate 12 measured using a stationary method defined in JIS C 6481 is preferably 0.2% or less, and 0.1% or less. It is more preferred that: When the warpage ratio is within such a range, it can be said that the warpage generated in the laminated board 10 has been corrected and flattened.

  Hereinafter, the present invention will be described based on examples. Note that the present invention is not limited to these examples.

1. Preparation of Raw Materials Raw materials used in the resin compositions of the respective examples and comparative examples are shown below.
-Thermosetting resin (1): bisphenol A type phenoxy resin ("1255" manufactured by Mitsubishi Chemical Corporation)
-Thermosetting resin (2): bisphenol A type epoxy resin ("850S" manufactured by DIC)
・ Curing agent (1): Dicyandiamide (manufactured by Degussa)
・ Curing accelerator (1): 2-phenylimidazole (“2PZ” manufactured by Shikoku Chemicals)
-Silane coupling agent (1): γ-glycidoxypropyltrimethoxysilane (“KBM-403” manufactured by Shin-Etsu Silicone Co., Ltd.)
-Filler (1): amorphous alumina ("LS-210B" manufactured by Nippon Light Metal Co., Ltd.)
-Filler (2): spherical alumina ("DAW-03" manufactured by Denka)

-Aluminum plate (1): Aluminum 6000 series ("A6061-T6" manufactured by Nippon Light Metal Co., Ltd., thickness: 0.6 mm, aluminum purity: 97.2 mass%, Brinell hardness: 105 HB)
-Aluminum plate (2): Aluminum 5000 series ("A5052-H34" manufactured by Nippon Light Metal Co., Ltd., thickness 0.6 mm, aluminum purity 97.2 mass%, Brinell hardness 82 HB)
-Aluminum plate (3): Aluminum 1000 series ("A1050-H24" manufactured by Nippon Light Metal Co., Ltd., thickness 0.6 mm, aluminum purity 99.5 mass%, Brinell hardness 30 HB)
In addition, even if the aluminum plate has the same product number, there are some which have different physical properties such as tensile strength depending on the lot. The tensile strength is shown in Table 1 below.

  ・ Copper foil (1): Rolled copper foil (“YGP-35” manufactured by Nihon Denshi) thickness 35 μm

2. Production of Laminated Plate A laminated plate was produced as follows.

<Preparation of resin composition>
As the thermosetting resin, the curing agent, the curing accelerator, the silane coupling agent, and the filler, those shown in Table 1 were weighed in parts by mass shown in Table 1. These were dissolved and mixed in 400 parts by mass of cyclohexanone, and stirred using a high-speed stirrer to prepare a resin composition.

<Deposition of a layer for forming an insulating resin layer on a copper foil>
The prepared copper foil (1) had a size of 260 mm in width and 35 μm in thickness. The resin composition prepared in advance is applied to the roughened surface of the copper foil (1) with a comma coater, and dried by heating at 100 ° C. for 3 minutes and at 150 ° C. for 3 minutes, thereby forming an insulating resin layer on the copper foil. A formation layer was formed. The thickness of the layer was adjusted so that the thickness of the insulating resin layer in the final laminated board had the value shown in Table 1. By drying the resin composition under these conditions, the insulating resin layer forming layer is in a semi-cured state. This was cut into a length of 65 mm and a width of 100 mm.

<Joint of aluminum plate on resin layer (layer for forming insulating resin layer)>
An aluminum plate (marked with “○” in Table 1) is placed on the insulating resin layer forming layer of the copper foil (1) on which the insulating resin layer forming layer has been formed. ) And the aluminum plate were pressed and heated so as to approach each other via the insulating resin layer forming layer. In this process, the layer for forming the insulating resin layer was cured to obtain a laminate in which the copper foil (1), the insulating resin layer, and the aluminum plate were laminated in this order. The conditions for heating and pressurizing were as follows.
・ Heating temperature: 180 ℃
・ Pressure during pressurization: 10MPa
・ Heating / pressurizing time: 1.5 hours

<Flatness>
Using the flattening apparatus 100, each of the laminates obtained above was subjected to a flattening process for correcting warpage. The flattening process using the flattening apparatus 100 used an apparatus having a separation distance L ₁ = 20 cm, a separation distance L ₂ = 20 cm, a length L ₃ = 5 cm, and a tensioner diameter = 15 cm. Due to this flattening, the laminates of Examples and Comparative Examples had a warpage ratio (defined in JIS C6481) of 0.2% or less.

3. Evaluation <3-point bending test>
The laminates obtained in each of the examples and comparative examples were cut to prepare test pieces having a length of 100 mm and a width of 25 mm. Each test piece was subjected to a three-point bending test in which a load was applied from the copper foil side under conditions of a fulcrum distance of 64 mm and a bending speed of 10 mm / min. Based on the stress-strain curve obtained by this test, 0.1% proof stress, 0.2% proof stress, 0.5% proof stress and stress at the time of 1% strain were determined.

<Crack generation>
Samples were prepared by bending the laminates obtained in each of the examples and comparative examples into an L shape. This sample was cut, and the bent portion of the cut surface was polished so that the presence or absence of cracks could be clearly determined, and then the presence or absence of cracks was observed. And it evaluated by the following criteria.
A: No cracks occurred B: Cracks occurred but no practical problems occurred C: Cracks occurred which caused a practical problem (dielectric breakdown occurred)

<Dielectric breakdown voltage value>
The laminates obtained in each of the examples and the comparative examples were cut to produce 8 cm square test pieces. The copper foil on one side was etched to form a 25 mmφ pattern at the center of the test piece. Then, after bending the test piece into an L-shape, the DC voltage was increased at a speed of 0.5 kV / s according to the withstand voltage test of JIS K 6911, and the potential at which the dielectric breakdown occurred was read to obtain the dielectric breakdown voltage value. .

  As is clear from Table 1, in each of the examples, that is, in the laminate having a 0.2% proof stress in the range of 200 to 295 MPa, generation of cracks was suppressed, and a good dielectric breakdown voltage value was exhibited. On the other hand, each of the comparative examples, that is, the laminate having a 0.2% proof stress out of the range of 200 to 295 MPa was inferior in crack generation as compared with the laminate of the example.

  This application claims priority based on Japanese Patent Application No. 2017-083567 filed on April 20, 2017, the disclosure of which is incorporated herein in its entirety.

Claims (8)

An aluminum-based copper-clad laminate,
An electrically insulating insulating resin layer having a thickness of 60 to 140 μm;
An aluminum plate having a thickness of 0.5 to 2.0 mm laminated on one surface of the insulating resin layer,
A copper foil having a thickness of 18 to 105 μm laminated on the other surface of the insulating resin layer,
When the aluminum base copper-clad laminate having a length of 100 mm and a width of 25 mm was subjected to a three-point bending test in which a load was applied from the copper foil side under a condition of a fulcrum distance of 64 mm and a bending speed of 10 mm / min, An aluminum-based copper-clad laminate having a 0.2% proof stress of 200 to 295 MPa.   The aluminum-based copper-clad laminate according to claim 1, wherein the aluminum-based copper-clad laminate having a length of 100 mm and a width of 25 mm has a distance between supporting points of 64 mm and a bending speed of 10 mm / min. An aluminum-based copper-clad laminate having a 0.1% proof stress of 185 to 285 MPa when subjected to a three-point bending test in which a load is applied from the copper foil side.   The aluminum-based copper-clad laminate according to claim 1 or 2, wherein the aluminum-based copper-clad laminate having a length of 100 mm and a width of 25 mm is provided at a distance between fulcrums of 64 mm and a bending speed of 10 mm / min. An aluminum-based copper-clad laminate having a 0.5% proof stress of 210 to 310 MPa when subjected to a three-point bending test in which a load is applied from the copper foil side.   The aluminum-based copper-clad laminate according to any one of claims 1 to 3, wherein a distance between fulcrum points of 64 mm and a distance of 10 mm / min for the aluminum-based copper-clad laminate having a length of 100 mm and a width of 25 mm. An aluminum-based copper-clad laminate, wherein a stress at the time of 1% distortion is 205 to 305 MPa when a three-point bending test in which a load is applied from the copper foil side is performed under a bending speed condition. The aluminum-based copper-clad laminate according to any one of claims 1 to 4,
An aluminum-based copper-clad laminate, wherein the aluminum plate is made of aluminum having a purity of 98.5 to 100% by mass.   The aluminum-based copper-clad laminate according to any one of claims 1 to 5, wherein a tensile strength of an aluminum material constituting the aluminum plate is 95 to 140 MPa. An aluminum-based copper-clad laminate according to any one of claims 1 to 6,
An aluminum-based copper-clad laminate, wherein the insulating resin layer includes at least one resin selected from an epoxy resin and a phenoxy resin. An aluminum-based copper-clad laminate according to claim 7, wherein
An aluminum-based copper-clad laminate, wherein the insulating resin layer further includes a filler.

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