JP2017170877A - Metal-clad laminate, printed wiring board, method for producing metal-clad laminate, and method for producing printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal-clad laminate capable of being formed into a printed wiring board which can sufficiently cope with thinning, hardly causes delamination when solder mounting even when its thickness is thin, and suppresses an amount of warpage due to a temperature change.SOLUTION: A metal-clad laminate 100 includes: an insulating layer 10 having a first surface 10a and a second surface 10b; a first metal layer 20 laminated on the first surface 10a of the insulating layer 10; and a second metal layer 30 laminated on the second surface 10b of the insulating layer 10. The insulating layer 10 includes a reinforcing material 11 and a cured product 12 of a thermosetting resin composition impregnated in the reinforcing material 11. A relationship between an interlayer thickness Ta1 between the first metal layer 20 and the second metal layer 30 and a thickness Tb1 of the reinforcing material 11 satisfies a relationship of 0≤Ta1-Tb1≤2 μm.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a metal-clad laminate, a printed wiring board, a method for producing a metal-clad laminate, and a method for producing a printed wiring board.

  In recent years, as electronic devices have higher functionality and higher density, electronic components are becoming increasingly smaller, highly integrated, faster, and multi-pinned. Along with this, the demand for higher density, smaller diameter, lighter weight and thinner printed wiring boards is also increasing. In particular, a printed wiring board having a small thickness is likely to warp.

  As copper-clad laminates that are less likely to warp even when they are thin, Patent Documents 1 and 2 disclose that a plurality of prepregs containing an inorganic filler are stacked, and copper foil is disposed on one or both sides of the prepreg, and a multistage vacuum A copper-clad laminate obtained by laminating by pressing is disclosed.

JP 2011-195476 A JP 2012-052110 A

  However, the copper-clad laminate obtained by the multistage vacuum press method as described in Patent Documents 1 and 2 may not be able to sufficiently meet the demand for thinning.

  In the production of a multilayer printed wiring board, the conductor circuit of the inner layer substrate must be embedded in the insulating layer. In a multilayer printed wiring board obtained by a multistage vacuum pressing method, the conductor circuit of the inner layer board is not sufficiently embedded in the insulating layer, and bubbles may remain in the insulating layer. This may cause delamination during soldering and mounting. Conventionally, in order to prevent the occurrence of delamination, the amount of resin constituting the insulating layer has to be increased, resulting in an increase in the thickness of the insulating layer, which limits the reduction in the thickness of multilayer printed wiring boards. was there. Furthermore, by increasing the amount of the resin constituting the insulating layer, the elastic modulus is lowered, and the multilayer printed wiring board is likely to be warped.

  Therefore, a metal-clad laminate that can sufficiently cope with thinning, can be a printed wiring board in which the amount of warpage due to temperature change is suppressed even when the thickness is thin, hardly causing delamination during solder mounting, It aims at providing the manufacturing method of a printed wiring board, a metal-clad laminated board, and the manufacturing method of a printed wiring board.

  A metal-clad laminate according to a first aspect of the present invention includes an insulating layer having a first surface and a second surface, a first metal layer stacked on the first surface of the insulating layer, and the insulating layer. A second metal layer laminated on a second surface, wherein the insulating layer includes a reinforcing material and a cured product of a thermosetting resin composition impregnated in the reinforcing material, and the first metal layer The relationship between the thickness Ta1 between the first metal layer and the second metal layer and the thickness Tb1 of the reinforcing material is 0 ≦ Ta1-Tb1 ≦ 2 μm.

  A metal-clad laminate according to a second aspect of the invention includes a first insulating layer, a conductor circuit laminated on the first insulating layer, and a first laminated on the first insulating layer and the conductor circuit. Two insulating layers, and a metal layer laminated on the second insulating layer, wherein the second insulating layer includes a reinforcing material and a cured product of a thermosetting resin composition impregnated in the reinforcing material. The relationship between the thickness Ta2 between the conductor circuit and the metal layer and the thickness Tb2 of the reinforcing material is 0 ≦ Ta2-Tb2 ≦ 2 μm.

  A printed wiring board according to a third invention includes a first insulating layer, a first conductor circuit laminated on the first insulating layer, the first insulating layer, and the first conductor circuit. A second insulating layer laminated on the second insulating layer, and a second conductor circuit laminated on the second insulating layer, wherein the second insulating layer is a thermosetting material impregnated with a reinforcing material and the reinforcing material. A relationship between an interlayer thickness Ta3 between the first conductor circuit and the second conductor circuit and a thickness Tb3 of the reinforcing material is 0 ≦ Ta3-Tb3 ≦ It is characterized by being 2 μm.

  According to a fourth aspect of the present invention, there is provided a metal-clad laminate manufacturing method comprising: preparing a core substrate having a conductor circuit on both sides or one side; and laminating a prepreg and a metal foil in this order on the surface having the conductor circuit. A laminate process for producing a laminate, and heating and pressurizing the laminate by continuously supplying the laminate between a pair of rotating endless belts and heating and pressing the laminate between the pair of endless belts. The prepreg includes a reinforcing material and a thermosetting resin composition impregnated in the reinforcing material, and an interlayer thickness Ta4 between the conductor circuit and the metal foil after heat and pressure molding, The relation with the thickness Tb4 of the reinforcing material is 0 ≦ Ta4-Tb4 ≦ 2 μm.

  According to a fifth aspect of the present invention, there is provided a printed wiring board manufacturing method, wherein a metal-clad laminate is manufactured by the method for manufacturing a metal-clad laminate, and a wiring formation process is performed on the metal foil.

  According to the present invention, it is possible to obtain a printed wiring board that can sufficiently cope with the reduction in thickness, is less likely to cause delamination at the time of soldering mounting even if the thickness is small, and suppresses the amount of warping due to temperature change.

FIG. 1 is a schematic cross-sectional view of a metal-clad laminate according to a first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of a metal-clad laminate according to the second embodiment of the present invention. FIG. 3 is a schematic cross-sectional view of the printed wiring board according to the embodiment of the present invention. 4A to 4D are explanatory diagrams for explaining a method for manufacturing a metal-clad laminate according to the first embodiment of the present invention. FIG. 5 is a schematic view of a double belt press apparatus. 6A to 6D are explanatory views for explaining a method of manufacturing a metal-clad laminate according to the second embodiment of the present invention. FIG. 7 is a schematic cross-sectional view of a metal-clad laminate according to the third embodiment of the present invention.

  Embodiments of the present invention will be described below.

[Metal-clad laminate 100 according to the first embodiment]
FIG. 1 is a schematic cross-sectional view of a metal-clad laminate 100 according to the first embodiment of the present invention.

  As shown in FIG. 1, the metal-clad laminate 100 includes an insulating layer 10 having a first surface 10 a and a second surface 10 b, a first metal layer 20, and a second metal layer 30. The first metal layer 20 is laminated on the first surface 10 a of the insulating layer 10. The second metal layer 30 is stacked on the second surface 10 b of the insulating layer 10. The insulating layer 10 includes a reinforcing material 11 and a cured product 12 of a thermosetting resin composition impregnated in the reinforcing material 11.

  In the first embodiment, as shown in FIG. 1, the thickness difference (Ta1−Tb1) between the interlayer thickness Ta1 between the first metal layer 20 and the second metal layer 30 and the thickness Tb1 of the reinforcing material 11. 0 ≦ Ta1-Tb1 ≦ 2 μm, preferably 1 μm ≦ Ta1-Tb1 ≦ 2 μm. If the thickness difference (Ta1-Tb1) exceeds 2 μm, there is a possibility that the printed wiring board cannot be sufficiently thinned. Moreover, if the range of thickness difference (Ta1-Tb1) is 1 μm or more and 2 μm or less, the reinforcing material 11, the first metal layer 20, and the second metal layer 30 (hereinafter sometimes referred to as metal layers 20, 30). And the metal-clad laminate 100 is more excellent in electrical reliability.

  The interlayer thickness Ta1 and the thickness Tb1 of the reinforcing material 11 can be measured in the same manner as described in the examples. In order to set the thickness difference (Ta1-Tb1) within the above range, for example, the metal-clad laminate 100 may be manufactured by a double belt press method capable of rapidly increasing the heating temperature, as will be described later. Further, when the insulating layer 10 is obtained by curing a laminate in which a plurality of prepregs including a reinforcing material 11 and a semi-cured material (B stage state) of a thermosetting resin composition contained in the reinforcing material 11 are stacked, The thickness Tb1 of the material 11 indicates the sum of the thicknesses of the plurality of reinforcing materials and the cured product of the thermosetting resin composition between adjacent reinforcing materials, and is similar to the thickness Tb1 of the reinforcing material 11 described above. Just measure.

  The plate thickness of the metal-clad laminate 100 is preferably 14 to 90 μm, more preferably 16 to 87 μm. The interlayer thickness Ta1 between the first metal layer 20 and the second metal layer 30 is preferably 10 to 50 μm, more preferably 12 to 47 μm. As the relationship between the thickness between the first metal layer 20 and the reinforcing material 11 and the thickness between the second metal layer 30 and the reinforcing material 11, the thickness difference (Ta1-Tb1) is within the above range. If it is, it will not specifically limit, For example, when the thickness between the 1st metal layer 20 and the reinforcing material 11 and the thickness between the 2nd metal layer 30 and the reinforcing material 11 are the same; When the thickness between one metal layer 20 and the reinforcing material 11 is 2 μm and the thickness between the second metal layer 30 and the reinforcing material 11 is 0 μm; the first metal layer 20 and the reinforcing material And the thickness between the second metal layer 30 and the reinforcing material 11 is 2 μm.

  The solder heat resistance of the metal-clad laminate 100 is preferably 260 ° C. or higher, more preferably 288 ° C. or higher. When the solder heat resistance of the metal-clad laminate 100 is within the above range, a printed wiring board can be obtained in which delamination is less likely to occur during solder mounting. The solder heat resistance can be measured in the same manner as described in the examples.

  The amount of warpage of the metal-clad laminate 100 is preferably 20 mm or less, more preferably 10 mm or less. When the warpage amount of the metal-clad laminate 100 is within the above range, a printed wiring board in which the warpage amount due to temperature change is further suppressed can be obtained. The amount of warpage can be measured in the same manner as described in the examples.

(Insulating layer 10)
The insulating layer 10 includes a reinforcing material 11 and a cured product 12 of a thermosetting resin composition impregnated in the reinforcing material 11.

  Examples of the reinforcing material 11 include a woven or non-woven fabric made of glass fiber; aramid fiber, PBO (polyparaphenylene benzobisoxazole) fiber, PBI (polybenzimidazole) fiber, PTFE (polytetrafluoroethylene) fiber, PBZT ( Polyparaphenylene benzobisthiazole) fiber, woven or non-woven fabric made of organic fiber such as wholly aromatic polyester fiber; woven or non-woven fabric made of inorganic fiber other than glass fiber; The woven structure of the reinforcing material 11 is not particularly limited, and examples thereof include plain weave and twill weave. Examples of the glass composition of the glass fiber include E glass, D glass, S glass, NE glass, T glass, and quartz. The reinforcing material 11 may be subjected to fiber opening treatment or may be subjected to surface treatment with a silane coupling agent or the like.

  The thermosetting resin composition constituting the cured product 12 of the thermosetting resin composition contains a thermosetting resin, and in addition to the thermosetting resin, a curing agent, a curing accelerator, an inorganic filler, a flame retardant. Etc. may be contained. As the thermosetting resin, for example, an epoxy resin, a polyimide resin, a phenol resin, a bismaleimide triazine resin, or the like can be used. As the curing agent, a diamine-based curing agent such as a primary amine or a secondary amine, a bifunctional or higher phenol-based curing agent, an acid anhydride-based curing agent, dicyandiamide, a low molecular weight polyphenylene ether compound, or the like can be used. . Examples of the curing accelerator include imidazole compounds such as 2-ethyl-4-methylimidazole (2E4MZ), tertiary amine compounds, organic phosphine compounds, and metal soaps. Examples of the inorganic filler include molybdenum compounds such as silica and molybdenum trioxide, aluminum hydroxide, magnesium hydroxide, aluminum silicate, magnesium silicate, talc, clay, mica, and the like. These may be used alone or in combination of two or more. The content of the inorganic filler is preferably 20 to 200 parts by mass with respect to 100 parts by mass of the total mass of the thermosetting resin and the curing agent. As the flame retardant, halogen-based flame retardants such as bromine-containing compounds, non-halogen-based flame retardants such as phosphorus-containing compounds and nitrogen-containing compounds can be used.

(First metal layer 20, second metal layer 30)
The first metal layer 20 and the second metal layer 30 are made of a foil-like metal. In other words, the metal layers 20 and 30 are made of an unpatterned planar metal. The first metal layer 20 and the second metal layer 30 may have the same configuration or different configurations.

  As a material constituting the metal layers 20 and 30, for example, copper, aluminum, stainless steel and the like can be used, and copper is preferably used. When the material of the metal layers 20 and 30 is copper, either electrolytic copper or rolled copper may be used. The thickness of the metal layers 20 and 30 is preferably 2 to 40 μm, more preferably 2 to 20 μm.

  It is preferable that at least one surface of the metal layers 20 and 30 is a mat surface. In this case, one surface of the metal foils 20 and 30 may be a mat surface, the other surfaces of the metal layers 20 and 30 may be shiny surfaces, and both surfaces of the metal layers 20 and 30 may be mat surfaces. If the mat surfaces of the metal layers 20 and 30 are arranged so as to face the prepreg and are heated and pressed, in the metal-clad laminate, the peel strength between the first metal layer 20 and the insulating layer 10 due to the anchor effect, The peel strength between the second metal layer 30 and the insulating layer 10 can be improved.

The ten-point average roughness (R _ZJIS ) of the mat surface is not particularly limited, and is preferably 0.5 to 5.0 μm. The ten-point average roughness (R _ZJIS ) of the shiny surface is not particularly limited, and is preferably 0.5 to 2.5 μm. The mat surface is formed with more dense irregularities than the shiny surface.

Here, the ten-point average roughness (R _ZJIS ) is defined in JIS B 0601-2013, and only the reference length is extracted from the roughness curve in the direction of the average line. Measured in the direction of the vertical magnification from the average line of the absolute value of the absolute value of the altitude (Yp) of the highest peak from the highest peak to the fifth, and the absolute value of the elevation (Yv) of the lowest peak from the lowest valley The sum of the value and the average value is obtained, and this value is expressed in micrometers (μm).

[Metal-clad laminate 101 according to the second embodiment]
FIG. 2 is a schematic cross-sectional view of the metal-clad laminate 101 according to the second embodiment of the present invention.

  As shown in FIG. 2, the metal-clad laminate 101 includes a first insulating layer 40, a conductor circuit 50, a second insulating layer 60, a metal layer 21 (hereinafter referred to as a first metal layer 21), A metal layer 31 (hereinafter, second metal layer 31). The conductor circuit 50 is laminated on the first insulating layer 40 (hereinafter referred to as the first surface 40a). The second insulating layer 60 is laminated on the first surface 40 a and the conductor circuit 50. The first metal layer 21 is stacked on the second insulating layer 60. The second metal layer 31 is laminated on the second surface 40 b of the first insulating layer 40. The second insulating layer 60 includes a reinforcing material 61 and a cured product 62 of a thermosetting resin impregnated in the reinforcing material 61.

  In the second embodiment, as shown in FIG. 2, the thickness difference (Ta2−Tb2) between the interlayer thickness Ta2 between the conductor circuit 50 and the first metal layer 21 and the thickness Tb2 of the reinforcing member 61 is 0 ≦ Ta2-Tb2 ≦ 2 μm, preferably 1 μm ≦ Ta2-Tb2 ≦ 2 μm. If the thickness difference (Ta2−Tb2) exceeds 2 μm, there is a possibility that the printed wiring board cannot be made sufficiently thin. Further, if the thickness difference (Ta2-Tb2) is 1 μm or more and 2 μm or less, the reinforcing member 61 is not easily in contact with the first metal layer 21 and the conductor circuit 50, and the metal-clad laminate 101 is more excellent in electrical reliability.

  The method for measuring the interlayer thickness Ta2 is the same as the method for measuring the interlayer thickness Ta1. The measuring method of the thickness Tb2 of the reinforcing material 61 is the same as the measuring method of the thickness Tb1 of the reinforcing material 11.

  The plate thickness of the metal-clad laminate 101 is preferably 26 to 160 μm, more preferably 30 to 150 μm. The interlayer thickness Ta2 between the conductor circuit 50 and the first metal layer 21 is preferably 10 to 50 μm, more preferably 12 to 47 μm. The interlayer thickness Tc between the conductor circuit 50 and the second metal layer 31 is preferably 10 to 50 μm, more preferably 12 to 47 μm. As a relationship between the thickness between the conductor circuit 50 and the reinforcing material 61 and the thickness between the first metal layer 21 and the reinforcing material 61, the thickness difference (Ta2-Tb2) is within the above range. For example, when the thickness between the conductor circuit 50 and the reinforcing material 61 and the thickness between the first metal layer 21 and the reinforcing material 61 are the same; the conductor circuit 50 and the reinforcing material 61 The thickness between the first metal layer 21 and the reinforcing member 61 is 0 μm; the thickness between the conductor circuit 50 and the reinforcing member 61 is 0 μm, When the thickness between one metal layer 21 and the reinforcing member 61 is 2 μm;

  The solder heat resistance of the metal-clad laminate 101 is preferably 260 ° C. or higher, more preferably 288 ° C. or higher. When the solder heat resistance of the metal-clad laminate 101 is within the above range, a printed wiring board can be obtained in which delamination is less likely to occur during solder mounting. The solder heat resistance can be measured in the same manner as described in the examples.

  The amount of warpage of the metal-clad laminate 101 is preferably 20 mm or less, more preferably 10 mm or less. If the warpage amount of the metal-clad laminate 101 is within the above range, a printed wiring board in which the warpage amount due to temperature change is further suppressed can be obtained. The amount of warpage can be measured in the same manner as described in the examples. The amount of warpage can be measured in the same manner as described in the examples.

(First insulating layer 40, second insulating layer 60)
The first insulating layer 40 includes a reinforcing material 41 and a cured product 42 of a thermosetting resin composition impregnated in the reinforcing material 41. The second insulating layer 60 includes a reinforcing material 61 and a cured product 62 of a thermosetting resin composition impregnated in the reinforcing material 61. The first insulating layer 40 and the second insulating layer 60 may have the same configuration or different configurations.

  The reinforcing materials 41 and 61 are not particularly limited, and for example, the same materials as those exemplified as the reinforcing material 11 can be used. It does not specifically limit as a thermosetting resin composition which comprises the 1st insulating layer 40, and a thermosetting resin composition which comprises the 2nd insulating layer 60, For example, the thermosetting which comprises the insulating layer 10 The thing similar to what was illustrated as a resin composition can be used.

  The thickness Td of the reinforcing member 41 is preferably 10 to 48 μm, more preferably 12 to 45 μm. The thickness Tb2 of the reinforcing member 61 is preferably 8 to 50 μm, more preferably 12 to 45 μm.

(Conductor circuit 50)
The conductor circuit 50 is a patterned layer and functions as an inner conductor pattern layer. As the conductor circuit 50, other than the patterning, for example, the same one as exemplified as the metal layers 20 and 30 can be used. The thickness A of the conductor circuit 50 is preferably 2 to 20 μm. The pattern of the conductor circuit 50 is not specifically limited, What is necessary is just to adjust suitably according to the use application of a printed wiring board.

(First metal layer 21, second metal layer 31)
The first metal layer 21 and the second metal layer 31 (hereinafter may be referred to as metal layers 21 and 31) are made of foil-like metal. In other words, the metal layers 21 and 31 are made of an unpatterned planar metal. As the metal layers 21 and 31, for example, the same materials as those exemplified as the metal layers 20 and 30 can be used.

  In addition, in 2nd embodiment, although it has the 2nd metal layer 31 laminated | stacked on the 2nd surface 40b of the 1st insulating layer 40, this invention is not limited to this, The metal-clad laminated board of this invention For example, a metal-clad laminate having the same configuration as that of the metal-clad laminate 101 may be used except that the second metal layer 31 is not provided, and the second metal layer 31 is not provided. A metal-clad laminate having the same configuration as the metal-clad laminate 101 may be used except that a plurality of conductor circuits and insulating layers are formed in this order on the two surfaces 40b. Moreover, in 2nd embodiment, although the 1st insulating layer 40 contains the reinforcing material 41, this invention is not limited to this, The 1st insulating layer does not need to contain a reinforcing material.

[Printed wiring board 200 according to this embodiment]
FIG. 3 is a schematic cross-sectional view of the printed wiring board 200 according to the embodiment of the present invention. In FIG. 3, the same components as those of the metal-clad laminate 101 according to the second embodiment shown in FIG.

  The printed wiring board 200 includes a first insulating layer 40, a first conductor circuit 50, a second insulating layer 60, a second conductor circuit 22, and a third conductor circuit 32. The first conductor circuit 50 is laminated on the first insulating layer 40 (hereinafter referred to as the first surface 40a). The second insulating layer 60 is laminated on the first surface 40 a and the first conductor circuit 50. The second conductor circuit 22 is laminated on the second insulating layer 60. The third conductor circuit 32 is laminated on the second surface 40 b of the first insulating layer 40. The second insulating layer 60 includes a reinforcing material 61 and a cured product 62 of a thermosetting resin impregnated in the reinforcing material 61.

  In the present embodiment, as shown in FIG. 3, the thickness difference (Ta3-Tb3) between the interlayer thickness Ta3 between the conductor circuit 50 and the second conductor circuit 22 and the thickness Tb3 of the reinforcing member 61 is 0 ≦ Ta3. −Tb3 ≦ 2 μm, preferably 1 μm ≦ Ta3-Tb3 ≦ 2 μm. If the thickness difference (Ta3-Tb3) exceeds 2 μm, when the thickness of the printed wiring board 200 is reduced, delamination is likely to occur during solder mounting, and the amount of warpage due to temperature changes may increase. There is a fear. Furthermore, there is a possibility that it cannot fully cope with the thinning. In addition, if the thickness difference (Ta3-Tb3) is 1 μm or more and 2 μm or less, the reinforcing member 61 is hardly in contact with the first conductor circuit 50 and the second conductor circuit 22, and the printed wiring board 200 is electrically reliable. Excellent. The interlayer thickness Ta3 corresponds to the interlayer thickness Ta2, and the thickness Tb3 corresponds to the thickness Tb2.

(Second conductor circuit 22, third conductor circuit 32)
The second conductor circuit 22 and the third conductor circuit 32 (hereinafter also referred to as conductor circuits 22 and 32) are respectively patterned layers, and both function as outer conductor pattern layers. The second conductor circuit 22 and the third conductor circuit 32 may have the same configuration or different configurations. As the conductor circuits 22 and 32, in addition to patterning, for example, the same ones exemplified as the metal layers 20 and 30 can be used. The thickness of the conductor circuits 22 and 32 is preferably 1 to 20 μm. The pattern of the conductor circuits 22 and 32 is not particularly limited, and may be adjusted as appropriate according to the use application of the printed wiring board.

  In the present embodiment, the third conductor layer 32 is laminated on the second surface 40b of the first insulating layer 40. However, the present invention is not limited to this, and the printed wiring board of the present invention includes: For example, a printed wiring board having the same configuration as that of the printed wiring board 200 may be used except that the third conductive layer 32 is not provided, or the second conductive layer 32 may not be provided on the second surface 40b. A printed wiring board having the same configuration as that of the printed wiring board 200 may be used except that a plurality of conductor circuits and insulating layers are formed in this order. Moreover, in this embodiment, although the 1st insulating layer 40 contains the reinforcing material 41, this invention is not limited to this, The 1st insulating layer does not need to contain a reinforcing material.

[Manufacturing method of metal-clad laminate according to first embodiment]
4A to 4D are explanatory views for explaining a manufacturing method of the metal-clad laminate 101 according to the first embodiment of the present invention (hereinafter, a manufacturing method according to the first embodiment). FIG. 5 is a schematic view showing a double belt press apparatus 300. 4A to 4D, the same components as those shown in the second embodiment of FIG.

  The manufacturing method according to the first embodiment includes a preparation process, a stacking process, and a heating and pressing process. In the preparation step, the core substrate 110 including the conductor circuit 50 on one side 40a (hereinafter sometimes referred to as the first side 40a) is prepared. In the laminating step, the prepreg 60a and the metal foil 21 are laminated in this order on the first surface 40a including the conductor circuit 50, thereby producing the laminate 101a having the configuration shown in FIG. 4D. In the heat and pressure molding process, as shown in FIG. 5, the laminate 101 a is continuously supplied between a pair of rotating endless belts 310, 310, and the laminate 101 a is placed between the pair of endless belts 310, 310. Heat-press molding. The prepreg 60a includes a reinforcing material 61a and a thermosetting resin semi-cured material 62a (B stage shape) impregnated in the reinforcing material 61a.

  The thickness difference (Ta4-Tb4) between the interlayer thickness Ta4 between the conductor circuit 50 after the heat and pressure molding and the first metal layer 21 and the thickness Tb4 of the reinforcing member 61a is 0 ≦ Ta4-Tb4 ≦ 2 μm. Preferably, 1 μm ≦ Ta 4 −Tb 4 ≦ 2 μm. In the manufacturing method according to the first embodiment, the interlayer thickness Ta4 corresponds to the interlayer thickness Ta2, and the thickness Tb4 corresponds to the thickness Tb2.

(Preparation process)
In the preparation step, the core substrate 110 provided with the conductor circuit 50 on one side 40a shown in FIG. 4B is prepared. Specifically, this preparation process includes a preliminary process and a circuit formation process. In the preliminary step, the conductor circuit forming metal layer 50a is formed on the first surface 40a of the first insulating layer 40, and the surface 40b opposite to the first surface 40a of the first insulating layer 40 (hereinafter referred to as the second surface 40b). A metal-clad laminate 110a shown in FIG. 4A, each having a second metal layer 31, is prepared. In the circuit forming step, the conductor circuit forming metal layer 50a is subjected to a wiring forming process to obtain the core substrate 110 shown in FIG. 4B.

  In the preliminary process, as a method of preparing the metal-clad laminate 110a, for example, an upper metal foil corresponding to the conductor circuit forming metal layer 50a, a prepreg corresponding to the first insulating layer 40, and a second metal layer The lower metal foil corresponding to 31 may be laminated and heated and pressed. The material which comprises this prepreg can use the thing similar to what was illustrated as a material which comprises the 1st insulating layer 40, for example. Examples of the method for heat and pressure molding include the same methods as those exemplified as the method for heat and pressure molding in the heat and pressure molding step described later. The wiring formation processing method in the circuit formation step is not particularly limited, and examples thereof include known circuit formation methods such as a subtractive method and a semi-additive method.

(Lamination process)
In the laminating step, as shown in FIG. 4C, the prepreg 60a and the metal foil 21 are laminated in this order on the first surface 40a including the conductor circuit 50, thereby producing the laminate 101a shown in FIG. 4D. What is necessary is just to adjust suitably the method of laminating | stacking suitably according to the method of heating-press shaping mentioned later.

  The prepreg 60a includes a reinforcing material 61a and a semi-cured product 62a of a thermosetting resin composition contained in the reinforcing material 61a. The thickness of the prepreg 60a is preferably 10 to 50 μm, more preferably 12 to 47 μm. The curing time (Geltime) of the prepreg 60a is preferably 60 to 600 seconds, more preferably 60 to 300 seconds. The volatile content of the prepreg 60a is preferably 1.5% or less, more preferably 1.0% or less. The method for measuring the thickness, resin content, resin flow, curing time, and volatile content of the prepreg 60a conforms to JIS 6521. In addition, hardening time (Geltime) is a case where it measures at 170 degreeC. The thickness of the reinforcing member 61a is preferably 10 to 50 μm, more preferably 12 to 45 μm. The method for measuring the thickness of the reinforcing member 61a can be measured in the same manner as the method described in the examples.

  The material which comprises the prepreg 60a can use the thing similar to what was illustrated as a material which comprises the insulating layer 60. FIG.

  It is preferable to preheat the laminate 101a before heat-press molding. In the double belt press method to be described later, the preheating is L in the period from the set of drums 320, 320 on the side of the feeders 340, 350, 360 to the hot press devices 330, 330 as shown in FIG. Refers to heating. For example, the preheating condition may be a heating temperature of 80 to 250 ° C. and a heating time of 5 to 200 s.

(Heat and pressure molding process)
In the heat and pressure molding process, as shown in FIG. 5, the laminate 101 a is continuously supplied between a pair of rotating endless belts 310, 310, and the laminate 101 a is placed between the pair of endless belts 310, 310. Heat-press molding. Thereby, the metal-clad laminate 101 is obtained.

  In the heat and pressure molding, as described above, a small amount of the laminate 101a of about one or several sheets is continuously supplied between the endless belts 310 and 310, and the endless belts 310 and 310 apply a surface pressure to the laminate 101a. It is carried out by a double belt press method that is heated together. As a result, the thickness difference (Ta4-Tb4) can be reduced to 2 μm or less, which could not be realized by the multistage vacuum press method, and can sufficiently cope with the thinning of the printed wiring board. The multistage vacuum press method is a method of stacking laminates in multiple stages via mirror plates at room temperature to obtain a laminate structure, inserting the resulting laminate structure between hot plates, heating it with a hot plate and applying it. It is a method to press.

  In the multistage vacuum press method, it takes a certain time for heat to be transferred from the outer side (hot plate side) of the laminated structure to the center side in the stacking direction of the laminate. As a result, the laminated structure cannot be heated rapidly, and is heated at a moderate temperature increase rate. When the laminated structure is heated and the melting temperature of the thermosetting resin is reached, the thermosetting resin composition melts and decreases in viscosity, and when further heated, it becomes a molten state and further decreases in viscosity. However, since the heating is performed at a moderate temperature increase rate, the thermosetting resin in the prepreg undergoes a thermosetting reaction even during the temperature increase before reaching the peak temperature. When the peak temperature is reached after the thermosetting reaction of the thermosetting resin proceeds to a certain degree, the viscosity at the peak temperature is not sufficiently lowered. Therefore, for example, when the metal-clad laminate 101 is manufactured by a multistage vacuum press method, the conductor circuit 50 is not sufficiently embedded in the insulating layer 60, and there is a possibility that delamination may occur during solder mounting. In order to suppress the occurrence of such delamination, it is effective to increase the amount of the cured product 62 of the thermosetting resin composition that constitutes the insulating layer 60, but this is sufficient for thinning the printed wiring board. I can not cope. Furthermore, in the multistage vacuum press method, there is a possibility that the amount of warpage of a thin printed wiring board is not sufficiently suppressed.

  On the other hand, in the double belt press method, the laminate 101a can be heated at the peak temperature without causing the thermosetting reaction of the thermosetting resin composition in the prepreg 60a, and the prepreg 60a at the peak temperature can be heated. The sufficient viscosity reduction of the thermosetting resin can be ensured. Therefore, pressure can be applied to the laminate 101a in a state where the viscosity is sufficiently low, and the gas generated in the prepreg 60a by the drums 320 and 320 is pushed out of the prepreg 60a by the drums 320 and 320. be able to. As a result, the metal-clad laminate 101 in which the conductor circuit 50 is embedded can be obtained without generating wrinkles or the like and without leaving bubbles in the insulating layer 60. For this reason, it is possible to obtain a printed wiring board that can sufficiently cope with a reduction in thickness, is less likely to cause delamination during solder mounting even if the thickness is small, and suppresses the amount of warpage due to temperature change.

<Double belt press method>
In the double belt press method, a double belt press apparatus 300 is used. As shown in FIG. 5, the double belt press device 300 includes a pair of endless belts 310, 310, two pairs of drums 320, 320, and hot-pressure devices 330, 330. Further, on the material supply side of the double belt press apparatus 300, a feeding machine 340 in which a long prepreg 60a is wound in a coil shape, and a feeding machine 350 in which a long metal foil 21 is wound in a coil shape, A feeding machine 360 in which a long core substrate 110 is wound in a coil shape is provided. A winder 370 that winds the long metal-clad laminate 101 into a coil shape is provided on the material outlet side of the double belt press apparatus 300.

  An endless belt 310 is hung on the pair of drums 320 and 320, and the endless belt 310 is rotated by rotating the drum 320. In the two pairs of drums 320 and 320, both surfaces of the laminate 101a supplied between the endless belts 310 and 310 are in surface contact with the endless belts 310 and 310, so that the laminate 101a is subjected to surface pressure. Are arranged as follows. The hot-pressing devices 330 and 330 are arranged inside the endless belts 310 and 310 so that the laminate 101a supplied between the endless belts 310 and 310 can be heated via the endless belt 310. The feeding machines 340, 350, and 360 are arranged so that the prepreg 60a, the metal foil 21, and the core substrate 110 are continuously fed out. The winder 370 is disposed so as to continuously wind up the metal-clad laminate 101.

  The heat and pressure molding by the double belt press method is specifically performed as follows without stacking a large amount of the laminate 101a in a multistage manner.

  First, the long prepreg 60a, the metal foil 21, and the core substrate 110 are fed out from the respective feeding machines 340, 350, and 360, and these are continuously supplied between the rotating endless belts 310 and 310. As shown in FIG. 4C, the prepreg 60a, the metal foil 21 and the core substrate 110 supplied between the endless belts 310 and 310 are formed on the surface 40a including the conductor circuit 50 of the core substrate 110. The stacked layers 101a are stacked in order. The pair of endless belts 310 and 310 rotate at a speed synchronized with the conveyance speed of the prepreg 60 a, the metal foil 21, and the core substrate 110. At this time, the endless belts 310 and 310 come into surface contact with both surfaces of the laminate 101a, and a surface pressure is applied to the laminate 101a.

  Next, the laminated plate 101a passes through a region (hereinafter referred to as a heating and pressing region) in which the heat and pressure device 330 is disposed in a state of being sandwiched between the pair of endless belts 310 and 310. When the laminated plate 101a passes through the heating and pressurizing region, the laminated plate 101a is subjected to surface pressure by the hot-pressing device 330 via the endless belt 310 and is heated and melted or softened prepreg 60a and the metal foil 21. The core substrate 110 is thermocompression bonded.

  Next, the laminate 101 a led out from the double belt press device 300 is cooled, becomes a metal-clad laminate 101, and is wound into a coil by a winder 370.

  As the material of the endless belt 310, for example, stainless steel can be used. Examples of the pressurizing mechanism of the hot-pressing device 330 include a press roll, a hydraulic pressure, and a press using a sliding pressurizing plate that are generally used as a pressurizing mechanism of a double belt press device. Examples of the heating means of the heat and pressure apparatus 330 include a heat medium circulation method and an induction heating method.

  The heating and pressing conditions by the double belt press method may be as follows, for example. When the heating temperature, the pressing force, and the heating and pressing time are within the following ranges, the metal-clad laminate 101 in which the conductor circuit 50 is embedded can be easily obtained.

  The lower limit of the heating temperature is preferably a temperature 3 ° C. higher than the melting point temperature of the thermosetting resin constituting the prepreg 60a, more preferably the melting point of the thermosetting resin. The upper limit of the heating temperature is preferably 20 ° C higher than the melting point of the thermosetting resin, more preferably 15 ° C higher than the melting point of the thermosetting resin. The heating rate when heating the laminate 101a to the curing temperature of the thermosetting resin is preferably 2 ° C./s or more, more preferably 3 to 5 ° C./s. The lower limit of the applied pressure is preferably 0.49 MPa, more preferably 2 MPa. The upper limit of the applied pressure is preferably 5.9 MPa, more preferably 5 MPa. The lower limit of the heating and pressing time is preferably 90 seconds, more preferably 120 seconds. The upper limit of the heating and pressing time is preferably 360 seconds, more preferably 240 seconds.

  In the manufacturing method according to the first embodiment, the core substrate 110 including the second metal layer 31 on the second surface 40b of the first insulating layer 40 is used. However, the present invention is not limited to this, and the present invention is not limited thereto. In the invention, a core substrate that does not include a metal layer on the second surface 40b of the first insulating layer 40 may be used.

[Manufacturing method of metal-clad laminate according to second embodiment]
6A to 6D are explanatory diagrams for explaining a method for manufacturing a metal-clad laminate according to the second embodiment of the present invention (hereinafter, a manufacturing method according to the second embodiment). FIG. 7 is a schematic cross-sectional view of the metal-clad laminate 102 according to the third embodiment of the present invention. 6A to 6D and FIG. 7, the same components as those shown in the manufacturing method according to the first embodiment of FIG.

  The manufacturing method according to the second embodiment includes a preparation process, a lamination process, and a heating and pressing process. Thereby, the metal-clad laminated board 102 of a structure shown in FIG. 7 is obtained. In the preparation step, the core substrate 120 having the first conductor circuit 50 and the second conductor circuit 51 on both surfaces 40a and 40b is prepared. In the stacking step, the prepreg 60a and the first metal foil 21 are stacked in this order on the first surface 40a of the core substrate 120, and the prepreg 70a and the second metal foil 31 are stacked on the second surface 40b of the core substrate 120. By sequentially laminating, a laminate 102a having the configuration shown in FIG. 6D is manufactured. In the heating and pressing process, the laminate 102a is heated and pressed. The prepreg 60a includes a reinforcing material 61a and a thermosetting resin semi-cured material 62a (B stage shape) impregnated in the reinforcing material 61a. The prepreg 70a includes a reinforcing material 71a and a thermosetting resin semi-cured material 72a (B stage shape) impregnated in the reinforcing material 71a. The prepreg 70a and the prepreg 60a may have the same configuration or different configurations.

  As shown in FIG. 7, the metal-clad laminate 102 includes a first insulating layer 40, a first conductor circuit 50, a second insulating layer 60, a first metal layer 21, and a second conductor. A circuit 51, a third insulating layer 70, and a second metal layer 31 are provided. The conductor circuit 50 is laminated on the first insulating layer 40 (hereinafter referred to as the first surface 40a). The second insulating layer 60 is laminated on the first surface 40 a and the conductor circuit 50. The first metal layer 21 is stacked on the second insulating layer 60. The second conductor circuit 51 is laminated on the second surface 40 b of the first insulating layer 40. The third insulating layer 70 is laminated on the second surface 40 b and the conductor circuit 51. The second metal layer 31 is stacked on the third insulating layer 70. The second insulating layer 60 includes a reinforcing material 61 and a cured product 62 of a thermosetting resin impregnated in the reinforcing material 61. The third insulating layer 70 includes a reinforcing material 71 and a cured product 72 of a thermosetting resin impregnated in the reinforcing material 71.

  The difference in thickness (Ta5-Tb5) between the interlayer thickness Ta5 between the first conductor circuit 50 and the first metal layer 21 after heating and pressing and the thickness Tb5 of the reinforcing member 61 is 0 ≦ Ta5-Tb5 ≦ 2 μm, preferably 1 μm ≦ Ta 5 −Tb 5 ≦ 2 μm. Further, the difference in thickness (Ta6-Tb6) between the interlayer thickness Ta6 between the second conductor circuit 51 and the second metal layer 31 after the heat and pressure molding and the thickness Tb6 of the reinforcing material 71 is 0 ≦ Ta6- Tb6 ≦ 2 μm, preferably 1 μm ≦ Ta6-Tb6 ≦ 2 μm. In the manufacturing method according to the second embodiment, the interlayer thickness Ta5 corresponds to the interlayer thickness Ta2, and the thickness Tb5 corresponds to the thickness Tb2. The method for measuring the interlayer thickness Ta6 is the same as the method for measuring the interlayer thickness Ta1. The measuring method of the thickness Tb6 of the reinforcing material 71 is the same as the measuring method of the thickness Tb1 of the reinforcing material 11.

(Preparation process)
In the preparation step, as shown in FIG. 6B, a core substrate 120 having a first conductor circuit 50 on the first surface 40a and a second conductor circuit 51 on the second surface 40b is prepared. Specifically, this preparation process includes a preliminary process and a circuit formation process. In the preliminary step, the first conductor circuit forming metal layer 50a is provided on the first surface 40a of the first insulating layer 40, and the second conductor circuit forming metal layer 31 is provided on the second surface 40b. A metal-clad laminate 110a to be shown is prepared. In the circuit forming step, the first conductor circuit forming metal layer 50a and the second conductor circuit forming metal layer 31 are respectively subjected to wiring forming processing to obtain the core substrate 120 shown in FIG. 6B.

  As a method for preparing the metal-clad laminate 110a in the preliminary process, for example, an upper metal foil corresponding to the first conductor circuit forming metal layer 50a, a prepreg corresponding to the first insulating layer 40, and a second The lower metal foil corresponding to the conductor circuit forming metal layer 31 may be laminated and heated and pressed. The material which comprises this prepreg can use the thing similar to what was illustrated as a material which comprises the 1st insulating layer 40, for example. Examples of the method for heat and pressure molding include the same methods as those exemplified as the method for heat and pressure molding in the heat and pressure molding step of the manufacturing method according to the first embodiment. In the circuit formation step, the method of wiring formation processing is not particularly limited, and examples thereof include known circuit formation methods such as a subtractive method and a semi-additive method.

(Lamination process)
In the stacking step, as shown in FIG. 6C, the prepreg 60a and the metal foil 21 are stacked in this order on the first surface 40a including the conductor circuit 50, and the prepreg 70a and the metal are stacked on the second surface 40b including the conductor circuit 51. By laminating the foils 31 in this order, the laminate 102a is produced. What is necessary is just to adjust suitably the method of laminating | stacking suitably according to the method of heating-press shaping mentioned later.

  As the material constituting the prepregs 60a and 70a, for example, the same materials as those exemplified as the material constituting the insulating layer 60 can be used.

  It is preferable that the laminate 102a is preheated before the heat and pressure molding. For example, the preheating condition may be a heating temperature of 80 to 250 ° C. and a heating time of 5 to 200 s.

(Heat and pressure molding process)
In the heating and pressing process, the laminate 102a is heated and pressed. Thereby, the metal-clad laminate 102 shown in FIG. 7 is obtained.

  Examples of the method for heat and pressure molding include the same methods as those exemplified as the method for heat and pressure molding in the production method of the first embodiment.

[Method for Manufacturing Printed Wiring Board According to this Embodiment]
In the method for manufacturing a printed wiring board according to the present embodiment, the metal-clad laminates 101 and 102 are manufactured by the method for manufacturing a metal-clad laminate according to the above-described embodiment, and a wiring formation process is performed on the metal foils 21 and 31. Thereby, a printed wiring board is obtained. The wiring formation processing method is not particularly limited, and examples thereof include known wiring formation processing methods such as a subtractive method and a semi-additive method.

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

[Example 1]
[Preparation process]
Using the following long prepreg, long lower metal foil (corresponding to the second metal layer 31) and long upper metal foil (corresponding to the metal layer 50a for forming a conductor circuit), the production shown in FIG. Using the apparatus, a long metal-clad laminate 110a having the configuration shown in FIG. 4A was obtained. Preheating conditions in the double belt press apparatus 300 were performed under the conditions of a heating temperature of 100 ° C. and a heating time of 30 s. The heating and pressing in the double belt press apparatus 300 was performed under the conditions of a heating temperature of 300 ° C., a pressing force of 40 MPa, and a heating and pressing time of 3 minutes.

(Long prepreg)
A product number “R-1410E” (plate thickness: 12 μm) manufactured by Panasonic Corporation was used. "R-1410E" is a resin after impregnating a glass cloth (glass composition: E glass) with a resin composition containing an epoxy resin, a phenolic curing agent and an inorganic filler such as silica, even if the plate thickness is different. The composition is produced by drying until it is in a semi-cured state. The blending ratio of the inorganic filler is 100 parts by mass with respect to 100 parts by mass of the epoxy resin and the phenolic curing agent.
(Long lower metal foil)
A product number “3EC-M2S-VLP” (thickness: 12 μm) manufactured by Mitsui Mining & Smelting Co., Ltd. was used.
(Long upper metal foil)
A product number “MicroThin Ex5” (thickness: 5 μm, surface roughness opposite to the surface on the prepreg side (Rzjis): 2 μm) manufactured by Mitsui Mining & Smelting Co., Ltd. was used.

  The conductor circuit forming metal layer 50a in the obtained long metal-clad laminate 110a was subjected to a wiring formation process by etching to form a conductor circuit 50, thereby obtaining the core substrate 110 having the configuration shown in FIG. 4B. The residual copper ratio at this time was 80%. Hereinafter, the circuit pattern was evaluated with the same circuit.

[Lamination process / Heat pressure molding process]
5 using the long core substrate 110, the following long prepreg 60a, and a long metal foil (corresponding to the first metal layer 21), the manufacturing apparatus shown in FIG. Was used to obtain a long metal-clad laminate 101 shown in FIG. Preheating conditions in the double belt press apparatus 300 were performed under the conditions of a heating temperature of 230 ° C. and a heating time of 30 s. The heating and pressurization in the double belt press apparatus 300 was performed under the conditions of a heating temperature of 300 ° C., a pressing force of 40 MPa, and a heating and pressing time of 3 minutes after heating from 200 ° C. to 300 ° C. at a temperature rising rate of 3 ° C./s.

(Long prepreg 60a)
Product number “R-1410E” manufactured by Panasonic Corporation (plate thickness: 12 μm, thickness of reinforcing material 61a: 12 μm, resin content: 54%, resin flow: 30%, curing time: 150 seconds, volatile content: 0. 5%) was used. The numerical values for the resin content, resin flow, curing time, and volatile content are catalog values, and the same applies to the numerical values for the resin content, resin flow, curing time, and volatile content shown below.

(Long metal foil)
A product number “3EC-M2S-VLP” (thickness: 12 μm, surface roughness of the prepreg side (Rzjis): 2 μm) manufactured by Mitsui Mining & Smelting Co., Ltd. was used.

[Preparation of Printed Wiring Board 200]
The metal layers 21 and 31 on both sides of the obtained long metal-clad laminate 101 are subjected to wiring formation processing by etching to form a second wiring conductor layer 22 and a third wiring conductor layer 32, and FIG. A long printed wiring board 200 having the configuration shown was obtained.

[Example 2]
In the [Lamination process / Heat pressure molding process], as a long prepreg 60a, a product number “R-1410E” manufactured by Panasonic Corporation (plate thickness: 14 μm, thickness of the reinforcing material 61a: 12 μm, resin content: 61 %, Resin flow: 30%, curing time: 150 seconds, volatile content: 0.5%) was used in the same manner as in Example 1 to obtain a printed wiring board 200 having the configuration shown in FIG.

[Example 3]
In the [preparation process], as a long upper metal foil, the product number “3EC-M2S-VLP” (thickness: 20 μm, surface roughness of the surface opposite to the prepreg side) Rzjis): 2 μm), the product number “R-1410E” (plate thickness: 45 μm, thickness of the reinforcing material 61a) manufactured by Panasonic Corporation is used as the long prepreg 60a in the [lamination process / heat press molding process]. 3 in the same manner as in Example 1 except that 45 μm, resin content: 48%, resin flow: 10%, curing time: 150 seconds, and volatile content: 0.5% were used. A wiring board 200 was obtained.

[Example 4]
In the [Lamination process / Heat and pressure molding process], as a long prepreg 60a, a product number “R-1410E” manufactured by Panasonic Corporation (plate thickness: 47 μm, thickness of the reinforcing material 61a: 45 μm, resin content: 50) %, Resin flow: 10%, curing time: 150 seconds, volatile content: 0.5%) was used in the same manner as in Example 3 to obtain a printed wiring board 200 having the configuration shown in FIG.

[Example 5]
5 using the following long prepreg, long lower metal foil (corresponding to the second metal layer 30), and long upper metal foil (corresponding to the first metal layer 20). The metal-clad laminate 100 having the configuration shown in FIG. 1 was obtained. Preheating conditions in the double belt press apparatus 300 were performed under the conditions of a heating temperature of 100 ° C. and a heating time of 30 s. The heating and pressurization in the double belt press apparatus 300 was performed under the conditions of a heating temperature of 300 ° C., a pressing force of 40 MPa, and a heating and pressing time of 3 minutes after heating from 200 ° C. to 300 ° C. at a heating temperature of 3 ° C./s.

(Long prepreg)
Part number “R-1410E” manufactured by Panasonic Corporation (plate thickness: 12 μm, thickness of reinforcing material corresponding to reinforcing material 11: 12 μm, resin content: 54%, resin flow: 30%, curing time: 150 seconds, Volatiles: 0.5%) was used.

(Long lower metal foil, upper metal foil)
A product number “3EC-M2S-VLP” (thickness: 12 μm, surface roughness of the prepreg side (Rzjis): 2 μm) manufactured by Mitsui Mining & Smelting Co., Ltd. was used.

[Example 6]
As a long prepreg, part number “R-1410E” manufactured by Panasonic Corporation (plate thickness: 14 μm, thickness of reinforcing material corresponding to reinforcing material 11: 12 μm, resin content: 59%, resin flow: 30%, A metal-clad laminate 100 having the structure shown in FIG. 1 was obtained in the same manner as in Example 5 except that the curing time was 150 seconds and the volatile content was 0.5%.

[Comparative Example 1]
[Preparation process]
Using a prepreg, a lower metal foil (corresponding to the second metal layer 31) and an upper metal foil (corresponding to the conductor circuit forming metal layer 50a), a metal-clad laminate having the structure shown in FIG. 110a was obtained. The heating and pressurization in the multistage vacuum press method was performed under the following conditions.

The unit pressure to be applied to the laminated structure is 0.49 to 0.98 MPa (5 to 10 kg / cm ² ) (primary pressure) for 20 to 30 minutes from the start of heat and pressure molding, and then the product temperature is 120 ° C. The pressure was increased to 2.94 MPa (30 kg / cm ² ) (secondary pressure). Thereafter, the secondary pressure was maintained until the heat pressing process was completed.

  The product temperature was heated at a rate of temperature increase of 1 to 3 ° C./min from the start of heat and pressure molding until the product temperature reached 160 ° C., and then the product temperature was maintained at 160 ° C. or higher for 50 minutes. The maximum product temperature at this time was 170 to 180 ° C. Thereafter, the laminate was allowed to cool at a cooling rate of 2 to 6 ° C./min until the temperature of the laminated plate reached room temperature.

  The atmosphere was maintained at 13.3 kPa (100 Torr) or lower until the product temperature reached 130 to 140 ° C., and then released to the atmosphere.

(Prepreg)
A product number “R-1410E” (plate thickness: 15 μm, resin content: 61%, resin flow: 30%, curing time: 150 seconds, volatile content: 0.5% seconds or less) manufactured by Panasonic Corporation was used.

(Lower metal foil)
A product number “3EC-M2S-VLP” (thickness: 12 μm) manufactured by Mitsui Mining & Smelting Co., Ltd. was used.

(Upper metal foil)
A product number “MicroThinEX5” (thickness: 5 μm, surface roughness opposite to the surface on the prepreg side (Rzjis): 2 μm) manufactured by Mitsui Mining & Smelting Co., Ltd. was used.

  The conductor circuit forming metal layer 50a in the obtained metal-clad laminate 110a was subjected to a wiring formation process by etching to form a conductor circuit 50, thereby obtaining the core substrate 110 having the configuration shown in FIG. 4B.

[Lamination process / Heat pressure molding process]
A metal-clad laminate 101 shown in FIG. 2 was obtained by a multistage vacuum pressing method using the core substrate 110, the following prepreg 60a, and metal foil (corresponding to the first metal layer 21). The heating and pressing conditions in the multistage vacuum press method were as follows.

The unit pressure to be applied to the laminated structure is 0.49 to 0.98 MPa (5 to 10 kg / cm ² ) (primary pressure) for 20 to 30 minutes from the start of heat and pressure molding, and then the product temperature is 120 ° C. The pressure was increased to 2.94 MPa (30 kg / cm ² ) (secondary pressure). Thereafter, the secondary pressure was maintained until the heat pressing process was completed.

  The product temperature was heated at a rate of temperature increase of 1 to 3 ° C./min from the start of heat and pressure molding until the product temperature reached 160 ° C., and then the product temperature was maintained at 160 ° C. or higher for 50 minutes. The maximum product temperature at this time was 170 to 180 ° C. Thereafter, the laminate was allowed to cool at a cooling rate of 2 to 6 ° C./min until the temperature of the laminated plate reached room temperature.

  The atmosphere was maintained at 13.3 kPa (100 Torr) or lower until the product temperature reached 130 to 140 ° C., and then released to the atmosphere.

(Prepreg 60a)
Product number “R-1410E” manufactured by Panasonic Corporation (plate thickness: 15 μm, thickness of reinforcing material 61a: 12 μm, resin content: 63%, resin flow: 30%, curing time: 150 seconds, volatile content: 0. 5%) was used.

(Metal foil)
A product number “3EC-M2S-VLP” (thickness: 12 μm, surface roughness of the prepreg side (Rzjis): 2 μm) manufactured by Mitsui Mining & Smelting Co., Ltd. was used.

[Preparation of Printed Wiring Board 200]
The metal layers 21 and 31 on both sides of the obtained long metal-clad laminate 101 are subjected to wiring formation processing by etching to form the second wiring conductor layer 22 and the third wiring conductor layer 32, and the configuration shown in FIG. The printed wiring board 200 was obtained.

[Comparative Example 2]
In the [lamination process / heat press molding process], as the prepreg 60a, a product number “R-1410E” manufactured by Panasonic Corporation (plate thickness: 17 μm, thickness of the reinforcing material 61a: 12 μm, resin content: 67%, resin A printed wiring board 200 was obtained in the same manner as in Comparative Example 1 except that the flow: 30%, the curing time: 150 seconds, and the volatile content: 0.5%.

[Comparative Example 3]
In the [preparation step], as the upper metal foil, a product number “3EC-M2S-VLP” (thickness: 20 μm, surface roughness of the prepreg side surface (Rzjis): 2 μm) manufactured by Mitsui Mining & Smelting Co., Ltd. is used. In the [lamination process / heat press molding process], as the prepreg 60a, the product number “R-1410E” (plate thickness: 48 μm, the thickness of the reinforcing material 61a: 45 μm, resin content: 50%, resin, manufactured by Panasonic Corporation 3 was obtained in the same manner as in Example 1 except that the flow: 10%, the curing time: 150 seconds, and the volatile content: 0.5% were used.

[Comparative Example 4]
In the [lamination process / heat press molding process], as the prepreg 60a, a product number “R-1410E” (plate thickness: 55 μm, thickness of the reinforcing material 61a: 45 μm, resin content: 55%, resin, manufactured by Panasonic Corporation A printed wiring board 200 was obtained in the same manner as in Comparative Example 3 except that the flow: 10%, the curing time: 150 seconds, and the volatile content: 0.5% were used.

[Comparative Example 5]
Using the following prepreg, lower metal foil (corresponding to the second metal layer 30) and upper metal foil (corresponding to the first metal layer 20), a metal-clad laminate having the structure shown in FIG. A plate 100 was obtained. The heating and pressing in the multistage vacuum press method was performed under the same conditions as the heating and pressing conditions in [Preparation step] of Comparative Example 1.

(Prepreg)
Part number “R-1410E” manufactured by Panasonic Corporation (plate thickness: 15 μm, thickness of reinforcing material corresponding to reinforcing material 11: 12 μm, resin content: 61%, resin flow: 30%, curing time: 150 seconds, Volatiles: 0.5%) was used.

(Lower metal foil, upper metal foil)
A product number “3EC-M2S-VLP” (thickness: 12 μm, surface roughness of the prepreg side (Rzjis): 2 μm) manufactured by Mitsui Mining & Smelting Co., Ltd. was used.

[Measurement of thickness]
In the metal-clad laminates 101 obtained in Examples 1 to 4 and Comparative Examples 1 to 4, the interlayer thickness Ta between the conductor circuit 50 and the first metal layer 21 is a digital microscope ("Keyence Co., Ltd." VH-Z500 "(hereinafter the same)), the cross section of the metal-clad laminate 101 was observed, and the second insulating layer of the first metal layer 21 in the thickness direction of the metal-clad laminate 101 as shown in FIG. The length between two points of the tip part on the 60 side and the tip part on the second insulating layer 60 side of the conductor circuit 50 was magnified 2000 times with a digital microscope and measured by a measurement function. Here, the tip of the first metal layer 21 on the second insulating layer 60 side is the lower surface of the first metal layer 21, as shown in FIG. This is the position that draws a straight line. As shown in FIG. 2, the tip portion of the conductor circuit 50 on the second insulating layer 60 side is a position that draws a straight line at the average position of the three copper foil convex portions on the upper surface of the conductor circuit 50.

  In the metal-clad laminate 101 obtained in Examples 1 to 4 and Comparative Examples 1 to 4, the thickness Tb of the reinforcing member 61 is a digital microscope, and a cross-sectional observation of the metal-clad laminate 101 is performed. As shown, in the thickness direction of the metal-clad laminate 101, the length between two points of the tip of the reinforcing member 61 on the first metal layer 21 side and the tip of the reinforcing member 61 on the conductor circuit 50 side is shown. Measurement was performed using a digital microscope measurement function. Here, the tip of the reinforcing material 61 on the first metal layer 21 side is the top surface of the reinforcing material 61 that is polished in the fiber direction of the warp 61a constituting the reinforcing material 61 as shown in FIG. This is a position for drawing a straight line in the upper part 61c. As shown in FIG. 2, the tip of the reinforcing member 61 on the conductor circuit 50 side is a lower surface of the reinforcing member 61, and a straight line is drawn to the lowermost part 61 d polished in the fiber direction of the warp 61 a constituting the reinforcing member 61. This is the position to be determined. In measuring the thickness Tb of the reinforcing member 61, the warp yarn 61a, not the weft yarn 61b constituting the reinforcing member 61, was used as a reference in the cross-sectional observation of the metal-clad laminate 101, as shown in FIG. This is because the cross-sectional shape of the weft yarn 61b constituting 61 is circular, and it is difficult to distinguish the weft yarn 61b from the inorganic filler. The same applies to the measurement of the thickness Tb of the reinforcing material 11, the thickness of the reinforcing material 61a, and the thickness of the reinforcing material corresponding to the reinforcing material 11.

  In the metal-clad laminate 100 obtained in Examples 5 and 6 and Comparative Example 5, the interlayer thickness Ta between the first metal layer 20 and the second metal layer 30 is a digital microscope. As shown in FIG. 1, in the thickness direction of the metal-clad laminate 100, the front end portion of the first metal layer 20 on the insulating layer 10 side and the insulating layer 10 of the second metal layer 30 are observed. The length between the two points with the tip on the side was magnified 2000 times with a digital microscope and measured by a measurement function. Here, as shown in FIG. 1, the tip portion of the first metal layer 20 on the insulating layer 10 side is a lower surface of the first metal layer 20, and a straight line is drawn at the average position of three copper foil convex portions. Position. As shown in FIG. 1, the tip of the second metal layer 30 on the insulating layer 10 side is a position that draws a straight line at the average position of three copper foil protrusions on the upper surface of the first metal layer 30. is there.

  In the metal-clad laminate 100 obtained in Examples 5 and 6 and Comparative Example 5, the thickness Tb of the reinforcing material 11 is a digital microscope, and the cross-section of the metal-clad laminate 100 is observed, as shown in FIG. Furthermore, in the thickness direction of the metal-clad laminate 100, the length between two points, that is, the tip of the reinforcing member 11 on the first metal layer 20 side and the tip of the reinforcing member 11 on the second metal layer 30 side. Was magnified 2000 times with a digital microscope and measured with a measurement function. Here, the tip of the reinforcing material 11 on the first metal layer 20 side is the top surface of the reinforcing material 11 that is polished in the fiber direction of the warp 11a constituting the reinforcing material 11 as shown in FIG. This is a position for drawing a straight line in the upper part 11c. As shown in FIG. 1, the distal end portion of the reinforcing material 11 on the second metal layer 30 side is a lower surface of the reinforcing material 11 and a lowermost part 11 d polished in the fiber direction of the warp 11 b constituting the reinforcing material 11. This is the position that draws a straight line.

  The thickness of the reinforcing material 61a used in Examples 1 to 4 and Comparative Examples 1 to 4 is a digital microscope, and a cross-sectional observation of the prepreg 61a is performed. As shown in FIG. The length between two points of the tip of the reinforcing member 61a on the first metal layer 21 side and the tip of the reinforcing member 61a on the conductor circuit 50 side is measured and measured. Here, the tip of the reinforcing material 61a on the first metal layer 21 side is the same as the above-described measurement of the thickness Tb of the reinforcing material 61 and the thickness Tb of the reinforcing material 11, as shown in FIG. 6C. On the upper surface of the material 61a, it is a position that draws a straight line on the uppermost portion polished in the fiber direction of the warp that constitutes the reinforcing material 61a. As shown in FIG. 6C, the tip of the reinforcing member 61a on the conductor circuit 50 side is a position where a straight line is drawn on the lower surface of the reinforcing member 61a polished in the fiber direction of the warp yarn constituting the reinforcing member 61a. is there.

  The thickness of the reinforcing material corresponding to the reinforcing material 11 used in Examples 5 and 6 and Comparative Example 5 was obtained by observing a cross section of the prepreg with a digital microscope, and in the thickness direction of the reinforcing material, the upper metal of the reinforcing material. It is measured by measuring the length between two points of the tip part on the foil side and the tip part on the lower metal foil side of the reinforcing material. Here, the tip of the reinforcing material on the upper metal foil side constitutes the reinforcing material on the upper surface of the reinforcing material, similarly to the measurement of the thickness Tb of the reinforcing material 61 and the thickness Tb of the reinforcing material 11 described above. This is a position that draws a straight line at the uppermost portion polished in the fiber direction of the warp. The tip of the lower metal foil side of the reinforcing material is the same as the measurement of the thickness Tb of the reinforcing material 61 and the thickness Tb of the reinforcing material 11 described above. This is a position that draws a straight line at the lowest part polished in the fiber direction.

[Solder heat resistance]
Using the double-sided metal-clad laminate obtained in each Example and Comparative Example as a test piece, the solder heat resistance was evaluated as follows in accordance with JIS C6481. The temperature of the molten solder was started at 200 ° C and increased by about 10 ° C. In the step of increasing the temperature of the molten solder, the test piece was left on the molten solder bath for 60 seconds at each temperature. Then, the sample piece was taken out from the molten solder bath, and the test piece was cooled to room temperature. The presence or absence of swelling of the test piece and delamination was confirmed visually. The highest temperature of the solder in which swelling and delamination were not confirmed was taken as the evaluation result.

[Evaluation of warpage]
The metal-clad laminate obtained in each Example and Comparative Example was cut out to obtain a test piece having a plan view size of 20 cm × 20 cm. After all the metal layers on both sides of the test piece were removed by etching, the test piece was heated at 200 ° C. for 1 hour.

  Subsequently, in the test pieces obtained in Examples 1 to 4 and Comparative Examples 1 to 4, the test pieces were arranged so that the first insulating layer 40 derived from the core substrate 110 was positioned above. In this state, the amount of warpage of the test piece was measured. The amount of warpage was defined as a positive value when the test piece was warped upward in a convex shape, and was defined as a negative value when the test piece was warped downward in a convex shape. The results are shown in Table 1.

100, 101, 102, 110a Metal-clad laminates 101a, 102a Laminates 110, 120 Core substrate 200 Printed wiring boards 10, 40, 60, 70 Insulating layers 11, 41, 61, 61a, 71, 71a Reinforcers 12, 42 , 62, 72 Cured product of thermosetting resin composition 20, 21, 30, 31, 50a Metal layer 22, 32, 50, 51 Conductor circuit 60a, 70a Pre-preg 62a, 72a Semi-cured product of thermosetting resin composition

Claims (7)

An insulating layer having a first surface and a second surface;
A first metal layer laminated on the first surface of the insulating layer;
A second metal layer laminated on the second surface of the insulating layer,
The insulating layer includes a reinforcing material and a cured product of a thermosetting resin composition impregnated in the reinforcing material,
The relationship between the interlayer thickness Ta1 between the first metal layer and the second metal layer and the thickness Tb1 of the reinforcing material is as follows:
0 ≦ Ta1-Tb1 ≦ 2 μm
A metal-clad laminate characterized by the above. A first insulating layer;
A conductor circuit laminated on the first insulating layer;
A second insulating layer laminated on the first insulating layer and the conductor circuit;
A metal layer laminated on the second insulating layer,
The second insulating layer includes a reinforcing material and a cured product of a thermosetting resin composition impregnated in the reinforcing material,
The relationship between the interlayer thickness Ta2 between the conductor circuit and the metal layer, and the thickness Tb2 of the reinforcing material,
0 ≦ Ta2-Tb2 ≦ 2 μm
A metal-clad laminate characterized by the above. A first insulating layer;
A first conductor circuit laminated on the first insulating layer;
A second insulating layer laminated on the first insulating layer and the first conductor circuit;
A second conductor circuit laminated on the second insulating layer,
The second insulating layer includes a reinforcing material and a cured product of a thermosetting resin composition impregnated in the reinforcing material,
The relationship between the interlayer thickness Ta3 between the first conductor circuit and the second conductor circuit, and the thickness Tb3 of the reinforcing material,
0 ≦ Ta3-Tb3 ≦ 2 μm
A printed wiring board characterized by the above. A preparation step of preparing a core substrate provided with a conductor circuit on both sides or one side;
A laminating step for producing a laminate by laminating a prepreg and a metal foil in this order on a surface including the conductor circuit;
A heating and pressing step of continuously supplying the laminate between a pair of rotating endless belts, and heating and pressing the laminate between the pair of endless belts;
The prepreg includes a reinforcing material and a thermosetting resin composition impregnated in the reinforcing material,
The relationship between the thickness Ta4 between the conductor circuit and the metal foil after heat and pressure molding, and the thickness Tb4 of the reinforcing material,
0 ≦ Ta4-Tb4 ≦ 2 μm
A method for producing a metal-clad laminate, wherein   5. The metal according to claim 4, wherein in the heat and pressure molding step, the laminate is heated from room temperature to a curing temperature of the thermosetting resin composition at a temperature rising rate of 3 ° C./s or more. A method for producing a tension laminate.   The method for producing a metal-clad laminate according to claim 4 or 5, wherein the laminate is preheated before the heating and pressing step. A metal-clad laminate is produced by the method according to any one of claims 4 to 6,
A method for producing a printed wiring board, comprising performing a wiring formation process on the metal foil.

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