JP2014198407A - Double-sided metal-clad laminate sheet and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double-sided metal-clad laminate sheet capable of inhibiting warpage even in a case where the respective thicknesses of metal foils on both surfaces thereof differ.SOLUTION: A double-sided metal-clad laminate sheet 1 is obtained by laminating and integrating: a first metal foil 21; an insulating layer 4 formed as a result of the curing of a resin composition and including at least one fiber substrate 3 in the interior thereof; and a second metal foil 22 thinner than the first metal foil 21. In a case where the thickness of a first cured resin layer 51 existing in-between the first metal foil 21 and the fiber substrate 3 closest to the first metal foil 21 is defined as Rand where the thickness of a second cured resin layer 52 existing in-between the second metal foil 22 and the fiber substrate 3 closest to the second metal foil 22 is defined as R, the relational formula of R≥2Ris satisfied.

Description

  The present invention relates to a double-sided metal-clad laminate used as a material for multilayer printed wiring boards and the like, and a method for producing the same.

  In recent years, for double-sided copper-clad laminates used for multilayer printed wiring boards, etc., due to the trend toward high capacity and information technology, thinning by increasing the number of layers is desired, and thin copper foil tends to be used. is there. A thin copper foil is also used when a circuit (conductor pattern) formed on the surface of a double-sided copper clad laminate is made into a fine pattern to increase the wiring density. In addition, the thickness of the insulating layer between the copper foils on both sides of the double-sided copper-clad laminate tends to be reduced to reduce the overall thickness.

  Under such circumstances, double-sided copper clad laminates having different thicknesses of copper foils on both sides are used. A thick copper foil is used on one side of the double-sided copper clad laminate to form a ground layer, and a thin copper foil is used on the other side for the above reasons.

  However, if the thicknesses of the copper foils on both sides of the double-sided copper-clad laminate with a thin overall plate thickness are made different, warping is likely to occur such that the thin copper foil side is convex and the thick copper foil side is concave. And the double-sided copper clad laminated board which generate | occur | produced the curvature in this way has the problem that conveyance defect arises, for example, being caught in the roll in the circuit formation process of the production line of a printed wiring board.

  By the way, Patent Document 1 describes an invention of a method for producing a double-sided copper-clad laminate for the purpose of reducing the warpage that occurs when a copper foil on one side is etched. In the double-sided copper-clad laminate described in Patent Document 1, as one aspect, a copper foil for circuit formation is disposed on the uppermost side, a copper foil for grounding is disposed on the lowermost side, and for circuit formation By making the thickness of the copper foil less than 52% of the thickness of the grounding copper foil, the occurrence of warpage after etching is suppressed. As another aspect, a copper foil for circuit formation is disposed on the uppermost side, a copper foil for grounding is disposed on the lowermost side, and the resin amount on the uppermost surface of the prepreg is compared with the resin amount on the lowermost surface. And by containing more than 10 weight%, generation | occurrence | production of the curvature after an etching is suppressed.

JP-A-7-22731

  However, the manufacturing method of the double-sided copper-clad laminate described in Patent Document 1 assumes that the warp after etching is assumed in any of the above aspects, and the double-sided copper-clad laminate is warped in advance in a direction to cancel the warp. That's it. Thus, since the double-sided copper clad laminate described in Patent Document 1 has warped from the beginning, there is a problem that a conveyance failure occurs such as being caught on a roll or the like in a production line of a printed wiring board.

  This invention is made | formed in view of said point, Even if it is a case where the thickness of metal foil of both surfaces differs, the double-sided metal clad laminated board which can suppress generation | occurrence | production of curvature, and its manufacturing method are provided. For the purpose.

The double-sided metal-clad laminate according to the present invention is
A first metal foil;
An insulating layer formed by curing the resin composition and including at least one or more fiber substrates; and
A second metal foil having a thickness smaller than that of the first metal foil;
Is a double-sided metal-clad laminate that is laminated and integrated.
And
Wherein the first metal foil, the thickness of the first resin cured layer existing between the nearest fiber base material in the first metal foil and R _1,
When the second metal foil, the thickness of the second resin cured layer existing between said second metal foil to the nearest fiber base material was changed to R _2,
R ₁ ≧ 2R ₂
The following relational expression is satisfied.

In the double-sided metal-clad laminate according to the present invention,
R ₁ ≧ 5R ₂
It is preferable that the following relational expression is satisfied.

The present invention also provides
The thickness of the first metal foil and M _1,
When the thickness of the second metal foil and a M _2,
M ₁ ≧ 1.4M ₂
It is suitably applied to a double-sided metal-clad laminate that satisfies the relational expression:

The method for producing a double-sided metal-clad laminate according to the first aspect of the present invention includes:
The fiber base material is impregnated with a resin composition, a first resin semi-cured layer is provided on one surface of the fiber base material, and the first resin semi-cured layer is formed on the other surface of the fiber base material. Using a base material uneven distribution type prepreg provided with a second resin semi-cured layer having a thickness smaller than the thickness,
The first resin semi-cured layer is disposed on one outermost layer, and the second resin semi-cured layer is disposed on the other outermost layer,
Laminating at least one base ubiquitous prepreg,
Overlaying the first metal foil on the outermost first resin semi-cured layer,
A second metal foil having a thickness smaller than that of the first metal foil is superimposed on the second resin semi-cured layer as the outermost layer, and is heated and pressed.

The method for producing a double-sided metal-clad laminate according to the second aspect of the present invention,
A first prepreg formed by impregnating a fiber base material with a resin composition, and provided with a first resin semi-cured layer on both sides of the fiber base;
A second prepreg formed by impregnating a fiber base material with a resin composition, and provided with a second resin semi-cured layer having a thickness smaller than the thickness of the first resin semi-cured layer on both surfaces of the fiber base;
Use
The first resin semi-cured layer is disposed on one outermost layer, and the second resin semi-cured layer is disposed on the other outermost layer,
Laminating at least one each of the first prepreg and the second prepreg,
Overlaying the first metal foil on the outermost first resin semi-cured layer,
A second metal foil having a thickness smaller than that of the first metal foil is superimposed on the second resin semi-cured layer as the outermost layer, and is heated and pressed.

  According to the present invention, a thick first resin cured layer is adjacent to a thick first metal foil, and a thin second resin cured layer is adjacent to a thin second metal foil. On both surfaces of the metal-clad laminate 1, the stress imbalance between the first metal foil 21 and the first resin cured layer 51 and between the second metal foil 22 and the second resin cured layer 52 is eliminated. be able to. Thereby, the residual stress of the double-sided metal-clad laminate 1 can be relaxed, and the occurrence of warpage of the double-sided metal-clad laminate can be suppressed.

An example of the manufacturing method of the double-sided metal-clad laminate which concerns on this invention is shown, (a) (b) is a schematic sectional drawing. The other example of the manufacturing method of the double-sided metal clad laminated board which concerns on this invention is shown, (a) (b) is a schematic sectional drawing. The other example of the manufacturing method of the double-sided metal clad laminated board which concerns on this invention is shown, (a) (b) is a schematic sectional drawing. The measuring method of the curvature of a double-sided metal-clad laminate is shown, (a) (b) is a schematic sectional drawing.

  Embodiments of the present invention will be described below.

(Embodiment 1)
FIG. 1B shows an example of a double-sided metal-clad laminate 1 according to the present invention. The double-sided metal-clad laminate 1 is formed by laminating and integrating a first metal foil 21, an insulating layer 4, and a second metal foil 22 in this order.

The material of the first metal foil 21 is not particularly limited. For example, a copper foil, a stainless steel foil, a nickel foil, a nichrome foil, or the like can be used. The thickness _{M 1} of the first metal foil 21, if thicker than the thickness _{M 2} of the second metal foil 22, is not particularly limited, for example, a 18～70Myuemu.

  The insulating layer 4 is formed of a cured resin obtained by curing the resin composition, and includes at least one or more fiber base materials 3 therein. The resin composition can contain, for example, a thermosetting resin, a curing agent, a curing accelerator, a filler, a flame retardant, and the like. As the thermosetting resin, for example, an epoxy resin, a polyphenylene ether resin, a phenol resin, a polyimide resin, or the like can be used. As the curing agent, for example, phenol compounds, cyanate compounds, styrene compounds, diamine compounds, acid anhydrides, dicyandiamide, polyamides, and the like can be used. As a hardening accelerator, what is suitable for hardening reaction of a thermosetting resin can be used suitably, For example, an imidazole type compound, an amine compound, a metal soap, etc. can be used. As the filler, for example, inorganic fillers such as silica, alumina, magnesium oxide, talc, aluminum hydroxide, and magnesium hydroxide, and organic fillers such as resin fillers can be used. As the flame retardant, known ones such as halogen flame retardants and phosphorus flame retardants can be appropriately used as desired. The material of the fiber base material 3 is not particularly limited. For example, inorganic fiber base materials such as glass cloth (glass cloth) and glass paper (glass nonwoven cloth), and woven cloth such as aramid (fully aromatic polyamide). Organic fiber base materials such as cloth and nonwoven fabric can be used. In the double-sided metal-clad laminate 1 shown in FIG. 1 (b), the insulating layer 4 contains one fiber base material 3 inside, which is shown in FIG. 2 (b) and FIG. 3 (b) described later. As described above, the insulating layer 4 may include two or more fiber base materials 3 inside. The thickness of the insulating layer 4 is not particularly limited, but is 30 to 300 μm.

The second metal foil 22 can be made of the same material as the first metal foil 21. The thickness _{M 2} of the second metal foil 22, if thin than the thickness _{M 1} of the first metal foil 21 is not particularly limited, for example, 7 to 35 m.

As described above, in the double-sided metal-clad laminate 1 according to the present invention, the relational expression of M ₁ > M ₂ is satisfied. The thick first metal foil 21 is used, for example, as a ground layer, a ground layer, a power supply layer, etc. in addition to a circuit forming layer. The thin second metal foil 22 is used as, for example, a circuit forming layer, particularly a layer on which a relatively dense conductor pattern is formed, an inner layer circuit of a multilayer printed wiring board, or the like.

In the present invention, if the thickness _{M 1} of the first metal foil 21 and the thickness _{M 2} of the second metal foil 22, in particular satisfies the relation _{M 1} ≧ 1.4M _2, the effect of remarkable warp suppressing Can be obtained. That is, if the difference between the thicknesses of M ₂ between the thickness M ₁ of the first metal foil 21 second metal foil 22 is large, the stress difference at both sides of the double-sided metal-clad laminate 1 is increased, as described below In the present invention, the occurrence of warpage can be suppressed by canceling the stress in the insulating layer 4.

  As shown in FIG. 1B, a first resin cured layer 51 exists between the first metal foil 21 and the fiber base 3. As shown in FIG. 2B and FIG. 3B, which will be described later, when the insulating layer 4 includes two or more fiber base materials 3, the first resin cured layer 51 is a first resin layer. It exists between the metal foil 21 and the fiber substrate 3 closest to the first metal foil 21. The first resin cured layer 51 is formed by completely curing a first resin semi-cured layer 81 of a later-described base material uneven prepreg 6 shown in FIG.

  On the other hand, as shown in FIG. 1B, a second resin cured layer 52 exists between the second metal foil 22 and the fiber base material 3. As shown in FIG. 2B and FIG. 3B described later, when the insulating layer 4 includes two or more fiber base materials 3 inside, the second resin cured layer 52 is the second resin cured layer 52. It exists between the metal foil 22 and the fiber substrate 3 closest to the second metal foil 22. The second resin cured layer 52 is formed by completely curing a second resin semi-cured layer 82 of a base material ubiquitous prepreg 6 described later shown in FIG.

In the double-sided metal-clad laminate 1 according to the present invention, when the thickness of the first resin cured layer 51 is R ₁ and the thickness of the second resin cured layer 52 is R ₂ , the relationship of R ₁ ≧ 2R ₂ The expression is satisfied. Here, the linear expansion coefficient of the cured resin that forms the first cured resin layer 51 and the second cured resin layer 52 is larger than that of the metal. Moreover, the influence of the stress on the linear expansion of the thick first resin cured layer 51 is larger than the influence of the stress on the linear expansion of the thin second resin cured layer 52. Therefore, the first resin cured layer 51 having a large thickness is adjacent to the first metal foil 21 having a large thickness, and the second resin cured layer 52 having a small thickness is adjacent to the second metal foil 22 having a small thickness. On both surfaces of the metal-clad laminate 1, the stress imbalance between the first metal foil 21 and the first resin cured layer 51 and between the second metal foil 22 and the second resin cured layer 52 is eliminated. be able to. Thereby, the residual stress of the double-sided metal-clad laminate 1 can be relaxed, and the occurrence of warpage of the double-sided metal-clad laminate 1 can be suppressed. At this time, it is particularly preferable that the relational expression of R ₁ ≧ 5R ₂ is satisfied, and more preferably R ₁ ≧ 10R ₂ . Thereby, generation | occurrence | production of the curvature of the double-sided metal-clad laminated board 1 can be suppressed more suitably.

  Next, the manufacturing method of said double-sided metal-clad laminate 1 is demonstrated.

  In manufacturing the double-sided metal-clad laminate 1 shown in FIG. 1 (b), a base material unevenly distributed prepreg 6 as shown in FIG. 1 (a) is used.

  In the base material uneven distribution type prepreg 6, the first resin semi-cured layer 81 is provided on one surface of the fiber base material 3, and the thickness is thinner than the thickness of the first resin semi-cured layer 81 on the other surface of the fiber base material 3. The second resin semi-cured layer 82 is provided. Thus, the fiber base material 3 is unevenly distributed on the second resin semi-cured layer 82 side from the central portion in the thickness direction of the base material uneven prepreg 6. Such a base material uneven distribution type prepreg 6 is basically prepared by dissolving the resin composition in an appropriate solvent (toluene or the like) to prepare a varnish, impregnating the fiber base material 3 with this varnish, Although it can manufacture by heat-drying until it will be in a semi-hardened state, the fiber base material 3 can be unevenly distributed as follows, for example. That is, after impregnating the fiber base material 3 with the varnish, the fiber base material is adhered to the one surface with a roll coater or the like, or the varnish is removed from the other surface with a squeegee or the like. 3 can be unevenly distributed from the central portion in the thickness direction to one side. Further, by applying different amounts of varnish from both sides to the fiber base material 3 by using a varnish coating device, and making the impregnation amount of the varnish on both sides of the fiber base material 3 different, It can also be unevenly distributed from the center to one side.

  And as shown to Fig.1 (a), the 1st metal foil 21 is piled up on the 1st resin semi-hardened layer 81 of the base material uneven distribution type prepreg 6, and the 2nd metal foil 22 is the 2nd of the base material uneven distribution type prepreg 6. A double-sided metal-clad laminate 1 as shown in FIG. 1B can be manufactured by heating and press-molding over the resin semi-cured layer 82. The insulating layer 4 of the double-sided metal-clad laminate 1 is formed by completely curing a semi-cured base material uneven distribution type prepreg 6.

(Embodiment 2)
FIG. 2B shows another example of the double-sided metal-clad laminate 1 according to the present invention. This double-sided metal-clad laminate 1 is different from the double-sided metal-clad laminate 1 shown in FIG. 1 (b) in that the insulating layer 4 includes two fiber base materials 3 inside. Common. Therefore, the description about a common point is abbreviate | omitted.

  In manufacturing the double-sided metal-clad laminate 1 shown in FIG. 2B, two base material ubiquitous prepregs 6 are laminated and used. In this case, as shown in FIG. 2A, the first resin semi-cured layer 81 is disposed on one outermost layer, and the second resin semi-cured layer 82 is disposed on the other outermost layer. The base material uneven distribution type prepreg 6 is laminated. Then, the first metal foil 21 is overlaid on the outermost first resin semi-cured layer 81, and the second metal foil 22 is overlaid on the outermost second resin semi-cured layer 82 to perform heat and pressure molding, thereby FIG. A double-sided metal-clad laminate 1 as shown in (b) can be manufactured. The heating and pressing conditions are not particularly limited, but are the same as those in the first embodiment, for example. In FIG. 1, the double-sided metal-clad laminate 1 is manufactured using a single base material uneven prepreg 6 and in FIG. 2 two base material uneven prepregs 6. Since at least one or more mold prepregs 6 may be used, the double-sided metal-clad laminate 1 may be manufactured using three or more base material unevenly distributed prepregs 6.

(Embodiment 3)
FIG. 3B shows another example of the double-sided metal-clad laminate 1 according to the present invention. This double-sided metal-clad laminate 1 is different from the double-sided metal-clad laminate 1 shown in FIG. 1 (b) in that the insulating layer 4 includes two fiber base materials 3 inside. Common. Therefore, the description about a common point is abbreviate | omitted.

  In manufacturing the double-sided metal-clad laminate 1 shown in FIG. 3B, a first prepreg 71 and a second prepreg 72 as shown in FIG. 3A are used.

  The first prepreg 71 is formed by providing a first resin semi-cured layer 81 on both surfaces of the fiber substrate 3. Thus, the fiber base material 3 exists in the center part in the thickness direction of the first prepreg 71. Such a first prepreg 71 is prepared by dissolving the resin composition in an appropriate solvent to prepare a varnish, impregnating the varnish into the fiber base material 3, and heating and drying it until it is in a semi-cured state. Can be manufactured.

  The second prepreg 72 is formed by providing a second resin semi-cured layer 82 having a thickness smaller than that of the first resin semi-cured layer 81 on both surfaces of the fiber base 3. Thus, the fiber base material 3 exists in the center part in the thickness direction of the second prepreg 72. Such a second prepreg 72 is basically manufactured in the same manner as the first prepreg 71 because the thickness of the second resin semi-cured layer 82 is merely made thinner than the thickness of the first resin semi-cured layer 81. be able to.

  And as shown to Fig.3 (a), the 1st prepreg 71 and the 2nd prepreg 72 are laminated | stacked. Further, the first metal foil 21 is overlaid on the outermost first resin semi-cured layer 81, and the second metal foil 22 is overlaid on the outermost second resin semi-cured layer 82 and heat-pressed to form FIG. A double-sided metal-clad laminate 1 as shown in b) can be produced. The insulating layer 4 of the double-sided metal-clad laminate 1 is formed by completely curing the first prepreg 71 and the second prepreg 72 in a semi-cured state. The heating and pressing conditions are not particularly limited, but are the same as those in the first embodiment, for example. In FIG. 3, each of the first prepreg 71 and the second prepreg 72 is laminated one by one, but at least one or more of the first prepreg 71 and the second prepreg 72 may be laminated. In this case, the first resin semi-cured layer 81 is disposed on one outermost layer, and the second resin semi-cured layer 82 is disposed on the other outermost layer. The first metal foil 21 is overlaid on the outermost first resin semi-cured layer 81, and the second metal foil 22 is overlaid on the outermost second resin semi-cured layer 82 and heat-pressed to form a double-sided metal. The tension laminate 1 can be manufactured. The heating and pressing conditions in this case are not particularly limited, but are the same as those in the first embodiment, for example.

  Hereinafter, the present invention will be specifically described by way of examples.

(Preparation of varnish of resin composition)
First, the molecular weight of the high molecular weight polyphenylene ether resin was reduced as follows.

  200 g of toluene was placed in a 2000 mL flask equipped with a stirrer and a stirring blade. While controlling this flask at an internal temperature of 80 ° C., high molecular weight polyphenylene ether resin “Noryl PX9701” manufactured by Japan GE Plastics Co., Ltd .: 100 g, bisphenol A: 4.3 g, t-butylperoxyisopropyl monocarbonate. “Perbutyl I” manufactured by Nippon Oil & Fats Co., Ltd .: 2.94 g and cobalt naphthenate solution (8 mass% solution dissolved in toluene): 0.0042 g are added and stirred until the high molecular weight polyphenylene ether is completely dissolved. Thus, a low molecular weight polyphenylene ether resin was prepared.

  The low molecular weight polyphenylene ether resin was reprecipitated with a large amount of methanol to remove impurities, and dried at 80 ° C. under reduced pressure for 3 hours to completely remove toluene.

  Next, the low molecular weight polyphenylene ether resin obtained as described above was ethenylbenzylated as follows.

  200 g of the above low molecular weight polyphenylene ether resin is added to a 1 L three-necked flask equipped with a temperature controller, a stirrer, a cooling facility and a dropping funnel, and the ratio of chloromethylstyrene (p-chloromethylstyrene to m-chloromethylstyrene is 1: 1; manufactured by Tokyo Chemical Industry Co., Ltd.): 15 g, tetra-n-butylammonium bromide: 0.8 g, toluene: 400 g were charged, dissolved by stirring, the liquid temperature was adjusted to 75 ° C., and an aqueous sodium hydroxide solution (water Sodium oxide 10 g / water 10 g) was added dropwise over 20 minutes, and stirring was further continued at 75 ° C. for 4 hours. Next, after neutralizing the contents of the flask with a 10% by mass hydrochloric acid aqueous solution, a large amount of methanol was added to obtain ethenylbenzylated polyphenylene ether as a precipitate. The precipitate filtrate was washed three times with a mixed solution of methanol and water (mass ratio of 80:20) and then treated at 80 ° C./3 hours under reduced pressure to remove ethenylbenzylated solvent and water. The polyphenylene ether resin was taken out.

  The number average molecular weight (Mn) of the ethenylbenzylated polyphenylene ether resin obtained as described above was 3500 as measured by gel permeation chromatography (GPC). The number average molecular weight was measured using TSK guard column HXL-4 G4000HXL: 1, G3000HXL: 1, G2000HXL: 1, G1000HXL: 2 columns.

  And the varnish of the resin composition was prepared as follows using said ethenyl benzylated polyphenylene ether resin.

  First, ethenylbenzylated polyphenylene ether resin is dissolved in toluene heated to 70 ° C. in the blending amounts shown in Table 1, and further triallyl isocyanurate (“TAIC” manufactured by Nippon Kasei Co., Ltd.), α, α′− Di (t-butylperoxy) diisopropylbenzene (“Perbutyl P” manufactured by NOF Corporation), ethylenebis (pentabromophenyl) (“SAYTEX8010” manufactured by Albemarle Japan Co., Ltd.), fused silica (Electrochemical Co., Ltd.) ) "FB-5SDC") was added, and this was stirred and mixed to prepare a varnish of the resin composition.

Example 1
Using the varnish obtained as described above, the base material uneven distribution type prepreg 6 was manufactured as follows. After impregnating the fiber base 3 (glass cloth shown in Table 2) with the varnish described above, the varnish was excessively adhered to one surface by a roll coater, and the varnish was removed from the other surface with a squeegee, and this was then removed. Substrate uneven distribution type prepreg 6 was manufactured by heating and drying until it was in a cured state. In the base material uneven distribution type prepreg 6, the first resin semi-cured layer 81 is provided on one surface of the fiber base material 3, and the thickness of the other surface of the fiber base material 3 is larger than the thickness of the first resin semi-cured layer 81. A thin second resin semi-cured layer 82 is provided.

And besides the base material uneven distribution type prepreg 6, the double-sided metal-clad laminate 1 was manufactured as follows using copper foil as the first metal foil 21 and the second metal foil 22. Incidentally, showing the thickness _{M 2} of a thickness _{M 1} and the second metal foil 22 of the first metal foil 21 in Table 2.

As shown in FIG. 1A, the first metal foil 21 is overlaid on the first resin semi-cured layer 81 of the base material uneven distribution prepreg 6, and the second metal foil 22 is overlapped with the second resin half resin of the base material uneven distribution type prepreg 6. A double-sided metal-clad laminate 1 as shown in FIG. 1 (b) was manufactured by heating and pressure forming over the hardened layer 82. The heating and pressing conditions are 200 ° C. and 2.94 MPa. The thickness _{R 2} of a thickness _{R 1} and a second resin cured layer 52 of the first cured resin layer 51 shown in Table 2.

(Example 2)
The double-sided metal-clad laminate 1 was manufactured as follows using the base material uneven prepreg 6, the first metal foil 21, and the second metal foil 22 similar to those in Example 1.

  As shown in FIG. 2 (a), the two substrates are arranged such that the first resin semi-cured layer 81 is disposed on one outermost layer and the second resin semi-cured layer 82 is disposed on the other outermost layer. The uneven distribution type prepreg 6 was laminated. Then, the first metal foil 21 is overlaid on the outermost first resin semi-cured layer 81, and the second metal foil 22 is overlaid on the outermost second resin semi-cured layer 82 to perform heat and pressure molding, thereby FIG. A double-sided metal-clad laminate 1 as shown in (b) was produced. The conditions for heating and pressing are the same as in Example 1.

(Example 3)
Except that the thickness M ₂ of a thickness M ₁ and the second metal foil 22 of the first metal foil 21 were changed as shown in Table 2, were prepared sided metal-clad laminate 1 in the same manner as in Example 1.

Example 4
A first prepreg 71 and a second prepreg 72 were manufactured as follows using the same varnish and the fiber base material 3 as in Example 1.

  The first prepreg 71 was manufactured by impregnating the fiber base material 3 with varnish, adhering the same amount of varnish on both sides with a roll coater, and then heating and drying it until it was in a semi-cured state. In the first prepreg 71, first resin semi-cured layers 81 are provided on both surfaces of the fiber base 3.

  The second prepreg 72 was manufactured by impregnating the fiber base material 3 with varnish, removing the same amount of varnish from both sides with a squeegee, and then drying by heating until it was in a semi-cured state. The second prepreg 72 is provided with a second resin semi-cured layer 82 having a thickness smaller than that of the first resin semi-cured layer 81 on both surfaces of the fiber substrate 3.

  Then, in addition to the first prepreg 71 and the second prepreg 72 described above, the double-sided metal-clad laminate 1 is manufactured using the first metal foil 21 and the second metal foil 22 similar to those of the first embodiment as follows. did.

  As shown in FIG. 3A, a first prepreg 71 and a second prepreg 72 were laminated. Further, the first metal foil 21 is overlaid on the outermost first resin semi-cured layer 81, and the second metal foil 22 is overlaid on the outermost second resin semi-cured layer 82 and heat-pressed to form FIG. A double-sided metal-clad laminate 1 as shown in b) was produced. The conditions for heating and pressing are the same as in Example 1.

(Comparative Example 1)
The thickness R ₂ of a thickness R ₁ and a second resin cured layer 52 of the first resin cured layer 51 except for changing as shown in Table 2, were prepared sided metal-clad laminate 1 in the same manner as in Example 1.

(Comparative Example 2)
The thickness R ₂ of a thickness R ₁ and a second resin cured layer 52 of the first resin cured layer 51 except for changing as shown in Table 2, were prepared sided metal-clad laminate 1 in the same manner as in Example 2.

(Comparative Example 3)
Except that the thickness M ₂ of a thickness M ₁ and the second metal foil 22 of the first metal foil 21 were changed as shown in Table 2, were prepared sided metal-clad laminate 1 in the same manner as in Comparative Example 1.

(Warpage of double-sided metal-clad laminate)
A sample 10 obtained by cutting the double-sided metal-clad laminate 1 into a rectangular shape of 600 mm × 500 mm was used. The sample 10 is placed on the surface plate 11 as shown in FIGS. 4A and 4B, and the lifting amounts of the four corners of the sample 10 are measured using a steel tape measure 12 (minimum scale 1 mm). did. Then, the maximum value of the lift amount was set as the warp of the double-sided metal-clad laminate 1. The results are shown in Table 2.

  As is clear from Table 2, it was confirmed that the warpage of the double-sided metal-clad laminate 1 was suppressed in Examples 1-4 as compared with Comparative Examples 1-3.

DESCRIPTION OF SYMBOLS 1 Double-sided metal-clad laminate 21 1st metal foil 22 2nd metal foil 3 Fiber base material 4 Insulating layer 51 1st resin cured layer 52 2nd resin cured layer 6 Base material uneven distribution type prepreg 71 1st prepreg 72 2nd prepreg 81 First resin semi-cured layer 82 Second resin semi-cured layer

Claims (5)

A first metal foil;
An insulating layer formed by curing the resin composition and including at least one or more fiber substrates; and
A second metal foil having a thickness smaller than that of the first metal foil;
Is a double-sided metal-clad laminate with integrated lamination,
Wherein the first metal foil, the thickness of the first resin cured layer existing between the nearest fiber base material in the first metal foil and R _1,
When the second metal foil, the thickness of the second resin cured layer existing between said second metal foil to the nearest fiber base material was changed to R _2,
R ₁ ≧ 2R ₂
A double-sided metal-clad laminate characterized by satisfying the relational expression: R ₁ ≧ 5R ₂
The double-sided metal-clad laminate according to claim 1, wherein the following relational expression is satisfied. The thickness of the first metal foil and M _1,
When the thickness of the second metal foil and a M _2,
M ₁ ≧ 1.4M ₂
The double-sided metal-clad laminate according to claim 1 or 2, wherein the following relational expression is satisfied. A method for producing a double-sided metal-clad laminate according to any one of claims 1 to 3,
The fiber base material is impregnated with a resin composition, a first resin semi-cured layer is provided on one surface of the fiber base material, and the first resin semi-cured layer is formed on the other surface of the fiber base material. Using a base material uneven distribution type prepreg provided with a second resin semi-cured layer having a thickness smaller than the thickness,
The first resin semi-cured layer is disposed on one outermost layer, and the second resin semi-cured layer is disposed on the other outermost layer,
Laminating at least one base ubiquitous prepreg,
Overlaying the first metal foil on the outermost first resin semi-cured layer,
A method for producing a double-sided metal-clad laminate, wherein a second metal foil having a thickness smaller than that of the first metal foil is superimposed on the second resin semi-cured layer of the outermost layer and heat-pressed. A method for producing a double-sided metal-clad laminate according to any one of claims 1 to 3,
A first prepreg formed by impregnating a fiber base material with a resin composition, and provided with a first resin semi-cured layer on both sides of the fiber base;
A second prepreg formed by impregnating a fiber base material with a resin composition, and provided with a second resin semi-cured layer having a thickness smaller than the thickness of the first resin semi-cured layer on both surfaces of the fiber base;
Use
The first resin semi-cured layer is disposed on one outermost layer, and the second resin semi-cured layer is disposed on the other outermost layer,
Laminating at least one each of the first prepreg and the second prepreg,
Overlaying the first metal foil on the outermost first resin semi-cured layer,
A method for producing a double-sided metal-clad laminate, wherein a second metal foil having a thickness smaller than that of the first metal foil is superimposed on the second resin semi-cured layer of the outermost layer and heat-pressed.

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