WO2018193757A1

WO2018193757A1 - Aluminum base copper-clad laminated plate

Info

Publication number: WO2018193757A1
Application number: PCT/JP2018/009896
Authority: WO
Inventors: 大輔北原
Original assignee: 住友ベークライト株式会社
Priority date: 2017-04-20
Filing date: 2018-03-14
Publication date: 2018-10-25
Also published as: JPWO2018193757A1; CN110573336A

Abstract

An aluminum base copper-clad laminated plate comprises: an electrically-insulating insulating resin layer having a thickness of 60 to 140 μm; an aluminum plate laminated onto one surface of the insulating resin layer and having a thickness of 0.5 to 2.0 mm; and copper foil laminated onto the other surface of the insulating resin layer and having a thickness of 18 to 105 μm. When the aluminum base copper-clad laminated plate having a length of 100 mm and a width of 25 mm is subjected to a three-point bending test in which a load is applied from the copper foil side under the conditions of a supporting span of 64 mm and a bending rate of 10 mm/min, a 0.2% proof stress is 200 to 295 MPa.

Description

Aluminum base copper clad laminate

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

The technology related to a laminated plate (referred to herein as an aluminum-based copper-clad laminated plate or simply a laminated plate) having a copper foil layer or an insulating layer based on an aluminum plate is various technical fields such as electric -It is examined in the electronic field, the lighting field, etc. (for example, refer patent document 1).

JP 2005-281509 A

However, according to the study of the present inventor, the conventional aluminum-based copper clad laminate is not strong enough, and when used as, for example, an electrical / electronic component, cracks are generated in the insulating layer and the copper foil due to external force. There were easy problems and there was room for improvement.

The present inventor has intensively studied in order to achieve the above problems, and has found that an aluminum-based copper-clad laminate having a specific configuration solves the above problems.

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 a three-point bending test in which a load is applied from the copper foil side under the conditions of a distance between fulcrums of 64 mm and a bending speed 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 having a 0.2% proof stress of 200 to 295 MPa is provided.

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

The above-described object and other objects, features, and advantages will be further clarified by a preferred embodiment described below and the following drawings attached thereto.

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 obtain “proof strength”. 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 which concerns on embodiment of this 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 simply abbreviated as a laminate. Note that in all the drawings, the same components are denoted by the same reference numerals, and description thereof will be omitted as appropriate. In addition, the dimensional ratio in the drawing does not necessarily correspond to an actual article and may be exaggerated. Further, the description of “a to b” in the numerical range represents “a” to “b” unless otherwise specified.

<Aluminum-based copper-clad laminate>
FIG. 1 shows a cross section of an aluminum-based copper-clad laminate 10 according to this 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 an insulating plate. The copper foil 13 is laminated on the other surface of the resin layer 11 and has a thickness of 18 to 105 μm. The laminated plate 10 according to the present embodiment is a three-point bending method in which a load is applied from the copper foil 13 side on the laminated plate 10 having a length of 100 mm and a width of 25 mm under a condition of a distance between fulcrums of 64 mm and a bending speed of 10 mm / min. The aluminum base copper clad laminate 10 has a 0.2% proof stress of 200 to 295 MPa when the test is performed.

“Strength” is generally an index indicating the strength of a material whose yield point is not clear against plastic deformation. In this specification, “X% proof stress” means the tangential OE and the strain parallel to the tangent OE with respect to the elastic deformation region (region where load and displacement are directly proportional) of the stress-strain curve in the above three-point bending test. 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, the conventional laminated board was liable to generate cracks in the insulating layer and the copper foil due to external force. Therefore, as a result of trial and error, the present inventor made a three-point bending test under the conditions described in the present specification as the entire laminated plate 10 while setting each of the insulating resin layer 11, the aluminum plate 12, and the copper foil 13 to appropriate thicknesses. 0.2% proof stress at 200 to 295 MPa (preferably 205 to 280 MPa, more preferably 210 to 265 MPa). And it discovered that the crack generation of the insulating resin layer 11 and the copper foil 13 could be suppressed effectively by carrying out like this.

The reason for this is not always clear, but is presumed as follows. That is, in the three-point bending test, which is a test for simulating various external forces applied when the laminated plate 10 is mounted, by designing the laminated plate 10 to satisfy the above parameters, the entire laminated plate 10 is appropriately plastically deformed. However, the external force does not concentrate on one point and is appropriately absorbed. As a result, it is estimated that the crack of the insulating resin layer 11 and the copper foil 13 can be suppressed. In addition, as a result of suppressing the cracks, particularly when the laminated plate 10 according to the present embodiment is applied to an electric / electronic component, an effect that sufficient insulation is ensured even when an impact is applied can be expected.

The laminated board 10 according to the present embodiment is applied to the laminated board 10 having a length of 100 mm and a width of 25 mm by applying a load from the copper foil 13 side under the 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 laminated plate 10 has a 0.1% proof stress of 185 to 285 MPa. This value is more preferably 185 to 260 MPa, and further preferably 185 to 255 MPa.

Moreover, the laminated board 10 which concerns on this embodiment applies a load from the copper foil 13 side with respect to the said laminated board 10 of length 100mm and width 25mm on the conditions of the distance between fulcrums of 64mm, and the bending speed of 10 mm / min. When the three-point bending test is performed, it is preferable that the laminated plate 10 has a 0.5% proof stress of 210 to 310 MPa. This value is more preferably 210 to 285 MPa, and further preferably 215 to 280 MPa.

Furthermore, the laminate 10 according to the present embodiment applies a load from the copper foil 13 side to the laminate 10 having a length of 100 mm and a width of 25 mm 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 laminated plate 10 has a stress of 205 to 305 MPa when strained by 1%. This value is more preferably 205 to 290 MPa, and further preferably 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, 0.1% proof stress, 0.5% proof stress, 1% strain stress, and the like are, for example, the characteristics and thickness of the aluminum plate 12 used for the laminated plate 10 and the insulation. The raw material which comprises the resin layer 11, its component amount, the thickness of the insulating resin layer 11, the characteristic and thickness of the copper foil 13, the manufacturing conditions in the manufacturing method of the laminated board 10 mentioned later (For example, in process (2) mentioned later) It is possible to obtain a desired value by appropriately setting the heating and pressurizing conditions).

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

[Insulating resin layer 11]
The laminate 10 according to this 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. By setting it as this thickness, while being able to obtain sufficient electrical insulation, 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 insulating properties. Thereby, the aluminum plate 12 and the copper foil 13 are insulated. The insulating resin layer 11 is typically composed of a solidified product or a cured product formed by solidifying or curing the 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, polyamides (eg, nylon 6, nylon 46, nylon 66, nylon 610, nylon 612, nylon 11, nylon 12) , Nylon 6-12, nylon 6-66), thermoplastic polyimide, aromatic polyester and other liquid crystal polymers, polyphenylene oxide, polyphenylene sulfide, polycarbonate, polymethyl methacrylate, polyether, polyether ether ketone, polyether imide, polyacetal, Styrene, polyolefin, polyvinyl chloride, polyurethane, polyester, polyamide, polybutadiene, trans polyisoprene, fluoro rubber, Various thermoplastic elastomers fluorinated polyethylene and the like, etc., or a copolymer of these main, blend, and a polymer alloy or the like. You may use these in mixture of 2 or more types.

Examples of the thermosetting resin include phenoxy resin, epoxy resin, phenol resin, urea resin, melamine resin, polyester (unsaturated polyester) resin, polyimide resin, silicone resin, polyurethane resin, and the like. You may use these in mixture of 2 or more types.

It is preferable to use a thermosetting resin as the resin. More specifically, the resin composition includes at least one resin selected from an epoxy resin and a phenoxy resin, in other words, the insulating resin layer 11 to be formed is selected from an epoxy resin and a phenoxy resin. It preferably 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. In addition, the adhesion between the insulating resin layer 11 and the aluminum plate 12 or the copper foil 13 is improved. This can contribute to the suppression or prevention of delamination between layers when flattening is performed by pressing or the like in the manufacturing process of the laminated plate 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. A phenoxy resin having a structure having a plurality of these skeletons can also be used. Among these, it is preferable to use bisphenol A type or bisphenol F type phenoxy resin. A phenoxy resin having both a bisphenol A skeleton and a bisphenol F skeleton may be used.

The weight average molecular weight of the phenoxy resin is not particularly limited, but is preferably 4.0 × 10 ⁴ to 4.9 × 10 ⁴ . Thereby, the elastic modulus of the insulating resin layer 11 can be reduced, and the laminate 10 can be excellent in stress relaxation properties. For example, when a semiconductor device having a semiconductor element mounted thereon is manufactured using the laminated plate 10, the semiconductor device is more accurately suppressed from generating cracks and the like even under a rapid heating / cooling environment. Become.

The epoxy resin is not particularly limited as long as it is an epoxy resin having 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 carbocyclic structure) is preferable. By using such an epoxy resin (A), the adhesiveness 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 type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol E type epoxy resin, bisphenol M type epoxy resin, and bisphenol P. Type epoxy resin, bisphenol type epoxy resin such as bisphenol Z type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, novolac type epoxy resin such as tetraphenol group ethane type novolac type epoxy resin, biphenyl type epoxy resin, biphenylene Examples include arylalkylene type epoxy resins such as phenol aralkyl type epoxy resins having a skeleton, and epoxy resins such as naphthalene type epoxy resins. You may use these in combination of 2 or more type.

The resin content is usually 1 to 40% by mass, preferably 2 to 20% by mass, and more preferably 4 to 16% by mass, based on the entire nonvolatile components of the resin composition. By making content more than the said lower limit, it is excellent in stress relaxation property and can suppress generation | occurrence | production of a crack. Moreover, since moderate fluidity is ensured by making content below the said upper limit, it is desirable from a viewpoint of the manufacture aptitude of the laminated board 10. FIG.

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

The resin composition may further contain a curing catalyst (curing accelerator). Thereby, the sclerosis | hardenability of a resin composition can be improved. Examples of the curing catalyst include amine catalysts such as imidazoles, 1,8-diazabicyclo (5,4,0) undecene, phosphorus catalysts such as triphenylphosphine, and the like. Of these, imidazoles are preferred. Thereby, in particular, the fast curability and the storage stability of the resin composition can be sufficiently achieved.

Examples of imidazoles include 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, 1-cyanoethyl-2- Phenylimidazolium trimellitate, 2,4-diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine, 2,4-diamino-6- [2'-undecylimidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino-6- [2′-ethyl-4′methylimidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino-6 -[2'-methylimidazolyl- (1 ')]-ethyl-s-triazine isocyanuric acid adduct, with 2-phenylimidazole isocyanuric acid 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,4-diamino-6-vinyl-s-triazine, 2,4-diamino-6- And 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. Of these, 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, and more preferably 0.05 to 10% by mass based on the entire non-volatile components of the resin composition. When the content is equal to or higher than the lower limit value, the curability of the resin composition becomes more sufficient. On the other hand, when the content is equal to or lower than the upper limit value, the storability of the resin composition can be further improved. it can.

The resin composition preferably contains a coupling agent. Thereby, the adhesiveness with the aluminum plate 12 and the copper foil 13 can be improved more. Therefore, when the flattening process etc. are given to the laminated board 10, it suppresses that a crack generate | occur | produces in the insulating resin layer 11, and suppresses the insulating resin layer 11 peeling from the aluminum plate 12 or the copper foil 13. Can be expected to do.

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

The silane coupling agent is not particularly limited. For example, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-Glycidoxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, N-β (aminoethyl) γ-aminopropylmethyl Dimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysila N-phenyl-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, bis (3 -Triethoxysilylpropyl) tetrasulfane and the like. 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, and more preferably 0.5 to 10% by mass based on the entire nonvolatile components of the resin composition. When the content is equal to or higher than the lower limit, the above-described effect of increasing the adhesion becomes more sufficient. By setting the content to be equal to or lower than the upper limit, outgas and voids when forming the insulating resin layer 11 can be further suppressed.

The resin composition preferably contains a filler (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 laminated plate 10 according to this 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. You may use these in combination of 2 or more type.

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, it can be set as the inorganic filler excellent in thermal conductivity and insulation. Aluminum oxide is also preferable because of its versatility and availability at low cost.

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

The content of the filler is preferably 60 to 90% by mass, more preferably 70 to 85% by mass based on the total amount of nonvolatile components of the resin composition. It can be expected that the thermal conductivity of the insulating resin layer 11 is further improved by setting the value to be above the lower limit of the numerical range. By making it to be below the upper limit of this numerical range, it is excellent in stress relaxation properties and can suppress the generation of cracks.

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. Typically, the solvent is an organic solvent such as methyl ethyl ketone, acetone, toluene, or dimethylformaldehyde. That is, the resin composition typically has a varnish shape in which components such as the above resin are dissolved or dispersed in an organic solvent.

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. Although it does not specifically limit as a mixer used for mixing, For example, a disperser, a composite blade type stirrer, a bead mill, a homogenizer, etc. are mentioned.

[Aluminum plate 12]
A laminated plate 10 according to this 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. This thickness is preferably 0.5 to 1.0 mm, more preferably 0.6 to 0.8 mm. By setting this thickness, it is possible to achieve both impact resistance and ease of processing.

The aluminum plate 12 according to this 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. In addition, although it does not specifically limit as other atoms except an aluminum atom, For example, magnesium, calcium, oxygen, silicon etc. are mentioned. According to the knowledge 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 satisfying desired characteristics according to the present embodiment (for example, the laminated plate 10 having the above-described 0.2% proof stress value of 200 to 295 MPa). ) Is considered easy to manufacture.

As another viewpoint, the tensile strength of the aluminum material constituting the aluminum plate 12 is preferably 95 to 140 MPa, and more preferably 95 to 120 MPa. In addition, the tensile strength here is calculated | required by the method JISZ2241. Surprisingly, the present inventor, when selecting the aluminum plate 12 with reference to an index related to “tensile”, exhibits good performance against various impacts simulated by the “three-point bending test” (that is, due to external force). The knowledge that crack generation and dielectric breakdown can be suppressed) has been found. Incidentally, when the purity of the aluminum constituting the aluminum plate 12 is increased as described above, there is a tendency that the numerical value of the tensile strength easily falls within the preferable numerical range.

[Copper foil 13]
A laminated plate 10 according to this embodiment includes a copper foil 13 having a thickness of 18 to 105 μm laminated on the other surface of the insulating resin layer 11 (the surface opposite to the surface on which the aluminum plate 12 is present). . 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. By setting it as this thickness, a crack etc. become difficult to generate | occur | produce and sufficient function (for example, electrical conductivity, heat conductivity, etc.) as the copper foil 13 can be exhibited.

<Method for Manufacturing Aluminum Base Copper Clad Laminate 10>
The laminated board 10 which concerns on this embodiment is manufactured by the method of the following (1) (2) and (3) as an example. Of course, as long as the finally obtained laminate 10 has characteristics such as desired proof stress, the laminate 10 according to this 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 an insulating resin layer forming layer is formed on the copper foil 13 as shown in FIG. 11A is formed. This insulating resin layer forming layer 11A is obtained by supplying the above resin composition onto the copper foil 13 to form a layer and then drying it. And this insulating resin layer forming layer 11A turns into the insulating resin layer 11 by hardening or solidifying through the process (2) mentioned later.

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 inkjet 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 void and having a uniform thickness, and thus the insulating resin layer 11 can be formed more efficiently.

When the resin composition is applied to the step (1), it preferably has the following viscosity behavior. That is, when the resin composition was heated from 60 ° C. to a molten state at a rate of temperature increase of 3 ° C./min and a frequency of 1 Hz using a dynamic viscoelasticity measuring device, the melt viscosity decreased initially and the lowest It is preferable that after reaching the viscosity, it has a characteristic of further increasing, and the minimum melt viscosity is in the range of 1 × 10 ³ Pa · s to 1 × 10 ⁵ Pa · s.

When the minimum melt viscosity is not less 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. Moreover, the adhesiveness of the insulating resin layer 11 and the copper foil 13 can be improved further as the minimum melt viscosity is not more than the above upper limit. Due to these synergistic effects, the thermal conductivity and insulating properties of the laminate 10 can be further enhanced.

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

Furthermore, the resin composition preferably has a flow rate of 10 to 60%, more preferably 20 to 50%. This flow rate can be measured by the following procedure. First, 5-7 sheets of copper foil having an insulating resin layer formed of the resin composition of the present embodiment are cut into a predetermined size (50 mm × 50 mm), and the weight is measured. Next, after pressing for 5 minutes between hot plates maintained at an internal temperature of 175 ° C. and cooling, the resin that has flowed out is carefully dropped and the weight is measured again. The flow rate can be obtained by the following formula (I).
Flow rate (%) = (weight before measurement-weight after measurement) / (weight before measurement-copper foil weight) (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 prevented from entering the resin composition, and the resin composition The gas dissolved inside can be discharged to the outside. 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. Moreover, the insulation reliability of the laminated board 10 can be improved by suppressing generation | occurrence | production of a bubble more. In addition, the adhesion between the copper foil 13 and the insulating resin layer 11 can be improved.

The resin composition having such a viscosity behavior is, for example, the type and amount of the resin material described above, the type and amount of the inorganic filler, and, if the resin material contains a phenoxy resin, the type and amount of the resin material. It can be obtained by adjusting appropriately.

(2) Bonding 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 through the insulating resin layer forming layer 11A. And pressurize and heat. Thereby, 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 on the condition that the insulating resin layer forming layer 11A is cured to form the insulating resin layer 11 when the insulating resin layer forming layer 11A exhibits thermosetting properties. Heated and pressurized. Further, when the insulating resin layer forming layer 11A exhibits thermoplasticity, it is heated and pressurized under the condition of being solidified by cooling after being melted by heating and heating.

The heating and pressurizing conditions are appropriately set depending on the type of resin composition contained in the insulating resin layer forming layer 11A. The heating temperature is preferably set to 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. Furthermore, the heating and pressurizing time is preferably about 10 to 90 minutes, more preferably about 30 to 60 minutes.

By this heating and pressurization, the aluminum plate 12 is joined to the insulating resin layer forming layer 11 </ b> A, and the insulating resin layer forming layer 11 </ b> A is cured to form the insulating resin layer 11. The laminated board 10 with which the aluminum plate 12 was bonded together is obtained.

Prior to the bonding of the insulating resin layer forming layer 11A and the aluminum plate 12, the bonding surface of the aluminum plate 12 is brought into contact with water at 40 to 80 ° C. for 0.5 to 3 minutes. It is preferable to apply. Thereby, the adhesiveness of the insulating resin layer 11 and the aluminum plate 12 can be improved more.

(3) Planarization processing 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 thermal expansion coefficients. Warpage may occur. In that case, it is preferable to perform a flattening process to correct the warp as an optional step. Thereby, the flat laminated board 10 without a curvature is obtained.

The planarization process can be performed using, for example, the planarization 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 conveying means 120 has tensioners (tension rollers) 130, 131, 132, 140, 141, 142, 143.

As shown in FIG. 4, in the transport unit 120, the

tensioner

130, 131, 132, 140, 141, 142, 143 is provided with a seamless belt 110 having an annular shape when viewed from the side. , 141, 142, and 143, the seamless belt 110 is repeatedly sent out along the conveyance direction.

Note that the

tensioners

130, 131, 132, 140, 141, 142, and 143 each have a cylindrical outer shape, and are made of a metal material such as stainless steel. In addition, the

tensioners

130, 131, 132, 140, 141, 142, and 143 are disposed so that the rotation axes (center axes) face the same direction and are separated from each other. Furthermore, 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 seamless belt 110 that is in contact with the tensioner 140 is wound around. The seamless belt 110 is repeatedly sent out in a loop shape by changing the transport direction at the corner of the seamless belt 110 that is attached.

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

Among these tensioners 130 to 132, the center of the tensioner 130 and the tensioner 132 is arranged along the transport direction. The center of the tensioner 131 is shifted from the center of the tensioner 130 and the tensioner 132 in a direction perpendicular to the transport direction.

The seamless belt 110 is conveyed between the tensioners 130 to 132 arranged in this manner, and at this time, the conveyance 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, and 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 ~ 50 cm, and more preferably 15 ~ 30 cm. Further, when the tensioners 130 to 132 are viewed from the transport direction, the length L _{3 of the} region where the

tensioners

130 and 132 and the tensioner 131 overlap in the direction perpendicular to the transport direction is preferably 2 to 8 cm, and preferably 4 to 6 cm. More preferred. By setting the sizes and the like of the tensioners 130 to 132 within these ranges, it is possible to more reliably correct the warp generated in the laminated board 10.

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 this motor.

Moreover, it is preferable that the laminated board 10 in which the curvature was corrected has the curvature rate in the aluminum plate 12 measured using the stationary method prescribed | regulated to JISC6481, 0.2% or less, 0.1% The following is more preferable. When the warpage rate is within such a range, it can be said that the warpage generated in the laminated plate 10 has been corrected and flattened.

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

1. Preparation of raw materials The raw materials used in the resin compositions of 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 (DIC Corporation "850S")
Curing agent (1): Dicyandiamide (Degussa)
Curing accelerator (1): 2-phenylimidazole (“2PZ” manufactured by Shikoku Chemicals)
Silane coupling agent (1): γ-glycidoxypropyltrimethoxysilane (“KBM-403” manufactured by Shin-Etsu Silicone)
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)
Note that some aluminum plates have different physical properties such as tensile strength depending on the lot even if they have the same product number. The tensile strength is shown in Table 1 below.

Copper foil (1): Rolled copper foil (“YGP-35” manufactured by Nippon Electrolytic Co., Ltd.) thickness 35 μm

2. Manufacture of a laminated board The laminated board was manufactured as follows.

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

<Deposition of insulating resin layer forming layer on copper foil>
The prepared copper foil (1) was 260 mm wide and 35 μm thick. A 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, whereby an insulating resin layer is formed on the copper foil. A forming layer was formed. The thickness of the layer was adjusted so that the thickness of the insulating resin layer in the final laminated plate was a value shown in Table 1. In addition, the insulating resin layer forming layer is in a semi-cured state by drying the resin composition under such conditions. This was cut into 65 mm length × 100 mm width.

<Joint of aluminum plate on resin layer (insulating resin layer forming layer)>
On the insulating resin layer forming layer of the copper foil (1) on which the insulating resin layer forming layer is formed, an aluminum plate (those marked with “◯” in Table 1) is placed, and then the copper foil (1 ) And the aluminum plate were pressed and heated so as to approach each other through the insulating resin layer forming layer. By this step, the insulating resin layer forming layer was cured to obtain a laminated plate in which the copper foil (1), the insulating resin layer, and the aluminum plate were laminated in this order. The heating / pressurizing conditions were as follows.
-Heating temperature: 180 ° C
・ Pressure pressure: 10 MPa
・ Heating / pressurizing time: 1.5 hours

<Planarization>
About each of the laminated board obtained above, the planarization process which corrects curvature using the planarization apparatus 100 was performed. Incidentally, flattening processing using a planarization apparatus 100 was used the distance _L 1 = 20 cm, the distance _L 2 = 20 cm, length _L 3 = 5 cm, the apparatus of the tensioner diameter = 15cm. By this flattening process, the warp rate (specified in JIS C 6481) of the laminated plates of each example and each comparative example was 0.2% or less.

3. Evaluation <3-point bending test>
The laminates obtained in each Example and each Comparative Example were cut to prepare test pieces having a length of 100 mm and a width of 25 mm. About each test piece, the 3 point | piece bending test which applies a load from the said copper foil side was implemented on the conditions of the distance between fulcrums of 64 mm, and the bending speed of 10 mm / min. Based on the stress-strain curve obtained by this test, the 0.1% proof stress, 0.2% proof stress, 0.5% proof stress and 1% distorted stress were determined.

<Occurrence of cracks>
Samples were produced by bending the laminates obtained in each Example and each Comparative Example 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 discriminated, and the presence or absence of cracks was observed. And it evaluated by the following reference | standard.
A: Crack did not occur B: Crack occurred, but no problem in practical use C: Problem occurred in practical use (insulation breakdown occurred)

<Dielectric breakdown voltage value>
The laminates obtained in each example and each comparative example were cut to prepare 8 cm square test pieces. The copper foil on one side was etched to produce 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 boosted at a speed of 0.5 kV / s according to the withstand voltage test of JIS K 6911, and the dielectric breakdown potential was read to obtain the dielectric breakdown voltage value. .

As is apparent from Table 1, in each of the examples, that is, the laminated sheet having a 0.2% proof stress in the range of 200 to 295 MPa, the occurrence of cracks was suppressed and a good dielectric breakdown voltage value was exhibited. On the other hand, each comparative example, that is, a laminate having a 0.2% proof stress outside the range of 200 to 295 MPa, was inferior in terms of occurrence of cracks compared to the laminate of the example.

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

Claims

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 a three-point bending test in which a load is applied from the copper foil side under the conditions of a distance between fulcrums of 64 mm and a bending speed 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 having a 0.2% proof stress of 200 to 295 MPa.
The aluminum-based copper-clad laminate according to claim 1, wherein the aluminum-base copper-clad laminate having a length of 100 mm and a width of 25 mm is subjected to a distance between fulcrums 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 a three-point bending test in which a load is applied from the copper foil side is performed.
It is the aluminum base copper clad laminated board of Claim 1 or 2, Comprising: With respect to the said aluminum base copper clad laminated board of length 100mm and width 25mm, on the conditions of the distance between fulcrums of 64mm, and the bending speed of 10 mm / min. An aluminum-based copper-clad laminate having a 0.5% yield strength of 210 to 310 MPa when a three-point bending test in which a load is applied from the copper foil side is performed.
The aluminum-based copper-clad laminate according to any one of claims 1 to 3, wherein the distance between fulcrums of 64 mm is 10 mm / min with respect to the aluminum-based copper-clad laminate having a length of 100 mm and a width of 25 mm. An aluminum-based copper-clad laminate having a stress of 205 to 305 MPa when strained by 1% when a three-point bending test in which a load is applied from the copper foil side under a bending speed condition is performed.
The aluminum-based copper-clad laminate according to any one of claims 1 to 4,
An aluminum-based copper-clad laminate in which 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 the aluminum material constituting the aluminum plate has a tensile strength of 95 to 140 MPa.
The aluminum-based copper-clad laminate according to any one of claims 1 to 6,
An aluminum-based copper-clad laminate in which the insulating resin layer includes at least one resin selected from an epoxy resin and a phenoxy resin.
The aluminum-based copper-clad laminate according to claim 7,
The aluminum-based copper clad laminate, wherein the insulating resin layer further contains a filler.