JP7435165B2 - Manufacturing method of printed wiring board - Google Patents

Description

The present invention relates to a method for manufacturing a printed wiring board.

As a method for manufacturing printed wiring boards, a build-up method in which insulating layers and conductive layers are alternately stacked is known. In a manufacturing method using a build-up method, an insulating layer is generally formed by thermosetting a resin composition layer of a resin sheet having a resin composition layer provided on a support.

When thermally curing to form an insulating layer, the support expands due to heating, and the resin composition is pressed against the support near the edge of the support, causing the resin composition to swell. This raised resin composition rides on the support or swells to the extent that it exceeds the thickness of the support, which impairs the flatness of the insulating layer formed in the subsequent build-up process. The yield of printed wiring boards will decrease.

For example, Patent Document 1 discloses that the yield of printed wiring boards is improved by using a resin sheet including a support that exhibits shrinkage characteristics when a resin composition layer is thermally cured.

Japanese Patent Application Publication No. 2016-86195

As described in Patent Document 1, by using a support that shrinks when heated, it is possible to suppress the resin composition from being pressed against the support near the edge of the support, thereby suppressing swelling of the resin composition. be able to. As a result, it is possible to prevent the resin composition from swelling to the extent that it exceeds the thickness of the support.

However, as a result of intensive research by the present inventors, the resin composition flows and bleeds out when heated, so even when using a support that shrinks when heated, the resin composition slightly bleeds near the edges of the support. I found it to be exciting. That is, when laminating the resin sheet to the inner layer substrate, pressure may be applied to the resin composition layer. This pressure causes the resin composition contained in the resin composition layer to flow, which may cause bleed-out. According to bleed-out, the resin composition flows out even to areas where there is no support. This spilled resin composition may swell up even if it is not pressed against the edge of the support. For example, in areas where there is no support, a slight bulge may occur because the flow of the resin composition in the thickness direction is not suppressed by the support. Therefore, swelling may occur in the insulating layer.

In recent years, with the further miniaturization of printed wiring boards, printed wiring boards are sometimes manufactured by performing multi-stage lamination (multilayer lamination) in which insulating layers are laminated multiple times. Even if the bulge in the insulating layer is slight, if the insulating layer is stacked in multiple stages, the bulge will be amplified and cause a difference in the surface unevenness (undulation) of the stacked insulating layers. The yield of printed wiring boards that form this will be reduced. In particular, undulation occurs significantly when three or more insulating layers are stacked, and this problem becomes more prominent as the number of stacked insulating layers increases.

An object of the present invention is to provide a method for manufacturing a printed wiring board that can suppress a decrease in yield even if the printed wiring board has an insulating layer formed by laminating multiple layers.

As a result of intensive studies aimed at solving the above-mentioned problems, the present inventor found that the above-mentioned problems could be solved by using a resin sheet having a margin where no resin composition was applied, and the present invention was completed. .

That is, the present invention includes the following contents.
[1] (A) A first resin sheet including a first support and a first resin composition layer provided on the first support, and a first resin composition layer provided on the first support. a step of laminating the inner layer substrate so that the layer is bonded to the inner layer substrate;
(B) a step of thermally curing the first resin composition layer to form an insulating layer;
(C) a step of removing the first support; and (D) a second resin comprising a second support and a second resin composition layer provided on the second support. The steps of laminating the sheet on the insulating layer with the second resin composition layer facing the insulating layer side, thermosetting the second resin composition layer, and removing the second support are performed in this order. including,
Step (D) is repeated two or more times,
The first support has first margins in which the first resin composition layer is not provided at two or more ends of the first support,
A method for manufacturing a printed wiring board, wherein the second support has second margins in which the second resin composition layer is not provided at two or more ends of the second support.
[2] The method for manufacturing a printed wiring board according to [1], wherein step (D) is repeated three or more times.
[3] The first support is rectangular when viewed from the thickness direction, and the first margin is formed at the ends of two or more sides of the first support, [1] or [2] ] The method for manufacturing a printed wiring board according to.
[4] In any one of [1] to [3], the first margin is formed at the end of one side of the first support and the end of the side opposite to this side. A method of manufacturing the printed wiring board described.
[5] A first margin is formed at the end of one side of the first support and at the end of the opposite side, and the width of these two first margins is The method for manufacturing a printed wiring board according to any one of [1] to [4], which is substantially the same.
[6] The method for manufacturing a printed wiring board according to any one of [1] to [5], wherein the first margin has a width of 0.1 mm or more and 10 mm or less.
[7] The method for producing a printed wiring board according to any one of [1] to [6], wherein the first resin composition layer has a minimum melt viscosity of 10 poise or more and 1,000,000 poise or less.
[8] The second support is rectangular when viewed from the thickness direction, and the second margin is formed at the ends of two or more sides of the second support, [1] to [7] ] The method for manufacturing a printed wiring board according to any one of the above.
[9] In any one of [1] to [8], the second margin is formed at the end of one side of the second support and the end of the side opposite to this side. A method of manufacturing the printed wiring board described.
[10] A second margin is formed at the end of one side of the second support and at the end of the opposite side, and the width of these two second margins is The method for manufacturing a printed wiring board according to any one of [1] to [9], which is substantially the same.
[11] The method for manufacturing a printed wiring board according to any one of [1] to [10], wherein the second margin has a width of 0.1 mm or more and 10 mm or less.
[12] The method for producing a printed wiring board according to any one of [1] to [11], wherein the second resin composition layer has a minimum melt viscosity of 10 poise or more and 1,000,000 poise or less.

According to the present invention, it is possible to provide a method for manufacturing a printed wiring board that can suppress a decrease in yield even in the case of a printed wiring board having an insulating layer formed by laminating multiple layers.

FIG. 1 is a top view schematically showing a resin sheet according to an embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing a cross section of a resin sheet according to an embodiment of the present invention, taken at a position indicated by a dashed line AA in FIG. FIG. 3 is a cross-sectional view showing an example of a state in which a resin sheet is bonded to an inner layer substrate. FIG. 4 is a top view schematically showing a resin sheet according to another embodiment of the present invention.

Embodiments of the present invention will be described below with reference to the drawings. It should be noted that each drawing merely schematically shows the shape, size, and arrangement of the constituent elements to the extent that the invention can be understood. The present invention is not limited to the following embodiments, and each component can be modified as appropriate. Further, the configuration according to the embodiment of the present invention is not necessarily manufactured or used according to the arrangement shown in the illustrated example.

Before explaining the method of manufacturing a printed wiring board of the present invention, the resin sheet of the present invention and the method of manufacturing the same will be described.

[Resin sheet]
FIG. 1 is a top view schematically showing a resin sheet 1 according to an embodiment of the present invention. As shown in FIG. 1, the resin sheet 1 includes a support 2 and a resin composition layer 3 provided on the support 2 and containing a resin composition. The support 2 has margins 4 in which the resin composition layer 3 is not provided at two or more end portions 21 and 22 of the support 2 .

The support body 2 may have a polygonal shape when viewed from the thickness direction, and therefore may have a plurality of sides. In this embodiment, a rectangular support 2 will be described as an example when viewed from the thickness direction, so the support 2 has four sides 23 to 26. It is preferable that the margin portion 4 is provided at the ends 21 and 22 of two or more of the sides of the support 2. The term "end of the side of the support" refers to the end of the support near the side of the support, and specifically refers to a portion having a specific width that is continuous from the side.

FIG. 2 is a cross-sectional view schematically showing a cross section of the resin sheet 1 according to an embodiment of the present invention, taken at a position indicated by a dashed line AA in FIG. As shown in FIG. 2, the support 2 has a margin 4 at one end 21, a resin composition layer 3, and a margin 4 at another end 22 in one direction perpendicular to the thickness direction. However, it is preferable that they be arranged in this order. When the support body 2 is rectangular when viewed from the thickness direction as in this embodiment, the margin portion 4 is formed at the end 21 of one side 23 and the end 22 of the side 24 opposite to this side 23. It is preferable that In this case, the margin 4 of the end 21, the resin composition layer 3, and the margin 4 of the end 22 are arranged in this order in the direction perpendicular to the thickness direction and intersecting the side 23. Further, it is preferable that the margin portions 4 formed at the end 21 of one side 23 and the end 22 of the side 24 opposite to this side 23 have substantially the same width. Since the widths of both margin portions 4 are substantially the same, the stress generated during curing of the resin composition layer becomes equal, and it becomes possible to effectively suppress the occurrence of undulation. In this specification, "substantially" means that it may include errors such as dimensional errors, design errors, and manufacturing errors. For example, the error range can be ±5%, ±4%, ±3%, ±2%, ±1%, or ±0.5%.

FIG. 3 is an enlarged cross-sectional view schematically showing the vicinity of the side 23 of the support 1 when the resin sheet 1 according to an embodiment of the present invention is bonded to the inner layer substrate 10. Usually, the resin sheet 1 is laminated on the inner layer substrate 10 so that the resin composition layer 3 is bonded to the inner layer substrate 10. Then, the resin composition layer 3 is thermally cured with the support 2 provided to form an insulating layer.

Since pressure can be applied to the resin composition layer 3 during lamination, the resin composition contained in the resin composition layer 3 can flow. However, since the resin sheet 1 has the margin portion 4, the fluidized resin composition can remain in the gap between the inner layer substrate 10 and the support body 2. Therefore, movement of the fluidized resin composition in the thickness direction is suppressed by the margin portion 4 of the support 2, so that swelling of the resin composition layer 3 is suppressed. Therefore, swelling of the insulating layer can be suppressed. As a result, even if the insulating layers are laminated in multiple stages, it is possible to suppress the occurrence of undulations, thereby improving the yield of printed wiring boards.

FIG. 4 is a top view schematically showing a resin sheet 11 according to another embodiment of the present invention. As shown in FIG. 4, the resin sheet 11 may have margins 4 formed at three or more ends of the support 2, or may have margins formed at all ends of the support 2. good. For example, as in the example shown in FIG. 4, the margin portion 4 may be formed at all the ends 21, 22, 27, and 28 of the four sides 23 to 26 of the rectangular support 2 when viewed from the thickness direction. . In this case, it is preferable that the widths of the margin portions 4 are substantially the same.

The resin sheet can be manufactured as a longitudinal resin sheet, for example, by a roll-to-roll method using a longitudinal support. Then, the resin sheet manufactured in this manner can be cut into an appropriate shape (such as a rectangle) as necessary and used. In a resin sheet manufactured by this method, the margin portion is usually formed continuously in the longitudinal direction. Therefore, as shown in FIG. 1, for example, it is preferable that the margin portion 4 is formed continuously in the longitudinal direction of the support 2, and is formed continuously at two or more end portions 21 and 22 extending in the longitudinal direction of the support 2. It is more preferable that the

The margin portion 4 preferably has a predetermined width a from the viewpoint of ensuring that the fluidized resin composition remains between the inner layer substrate 10 and the margin portion 4 of the support 2 with high reliability. The width a of the margin portion 21 is preferably 0 from the viewpoint of suppressing the occurrence of undulations, suppressing peeling of the support during curing of the resin composition, and uniformizing the surface condition of the insulating layer formed. .1 mm or more, more preferably 0.3 mm or more, even more preferably 0.5 mm or more, or 0.6 mm or more, preferably 10 mm or less, more preferably 8 mm or less, still more preferably 7 mm or less, even more preferably 5 mm or less. , particularly preferably less than 5 mm.

The thickness of the support 2 is not particularly limited, but is preferably in the range of 5 μm to 75 μm, more preferably in the range of 10 μm to 60 μm. In addition, when using the support body with a mold release layer mentioned later, it is preferable that the thickness of the whole support body with a mold release layer is in the said range.

The minimum melt viscosity of the resin composition layer 3 is not particularly limited, but from the viewpoint of suppressing bleed-out of the resin composition, it is preferably 10 poise or more, more preferably 50 poise or more, and still more preferably 100 poise or more. The upper limit of the minimum melt viscosity of the resin composition layer 3 is preferably 1,000,000 poise or less, more preferably 100,000 poise or less, still more preferably 10,000 poise or less, from the viewpoint of achieving good lamination properties.

Here, the "minimum melt viscosity" of the resin composition layer refers to the lowest viscosity that the resin composition layer exhibits when the resin of the resin composition layer is melted. In detail, when the resin composition layer is heated at a constant temperature increase rate to melt the resin, the melt viscosity decreases as the temperature rises in the initial stage, and then, when the temperature exceeds a certain temperature, the melt viscosity decreases as the temperature rises. Rise. "Minimum melt viscosity" refers to the melt viscosity at such minimum point. The minimum melt viscosity and minimum melt viscosity temperature of the resin composition layer can be measured by a dynamic viscoelasticity method.

The thickness of the resin composition layer 3 is preferably 5 μm to 100 μm, more preferably 7.5 μm to 90 μm, and even more preferably 10 μm to 80 μm, from the viewpoint of suppressing the occurrence of undulation.

Each layer constituting the resin sheet will be described in detail below.

<Support>
The resin sheet has a support. Examples of the support include a film made of a plastic material, a metal foil, and a release paper, and a film made of a plastic material and a metal foil are preferred.

When using a film made of a plastic material as a support, examples of the plastic material include polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate (hereinafter sometimes abbreviated as "PEN"). ), polyesters such as polycarbonate (hereinafter sometimes abbreviated as "PC"), acrylics such as polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether Examples include ketones and polyimides. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, and inexpensive polyethylene terephthalate is particularly preferred.

When using metal foil as the support, examples of the metal foil include copper foil, aluminum foil, etc., with copper foil being preferred. As the copper foil, a foil made of a single metal such as copper may be used, or a foil made of an alloy of copper and other metals (for example, tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) may be used. May be used.

Generally, a support expands or contracts when heated, although the degree of expansion and/or contraction upon heating varies depending on the type of support. The direction of expansion or contraction of the support differs depending on the manufacturing process (for example, the selection of the constituent material of the support, the tension applied when the support is wound up (transported), etc.), but TD direction, or MD direction.

Here, the term "MD direction (Machine Direction)" refers to the longitudinal direction of the support, that is, the direction in which the long support is transported during manufacturing. Further, the term "TD direction (Transverse Direction)" refers to the width direction of the support, and is a direction perpendicular to the MD direction. Note that both the MD direction and the TD direction are directions perpendicular to the thickness direction of the support.

As a method for preparing the support, it is preferable to perform a preliminary heating treatment from the viewpoint of suppressing expansion or contraction during heating. The conditions of the preheating treatment can be adjusted depending on the type of plastic material, the presence or absence of tension (stretching) applied during manufacturing, the axial direction of stretching, the degree of stretching, the heat treatment conditions after stretching, etc.

When a long film made of a plastic material is used as the film made of a plastic material, the preheating treatment may include, for example, applying tension to the film made of the plastic material in one or both of the MD direction and the TD direction. An example of this is heating.

When using a long film made of plastic material, a predetermined tension is usually applied in the MD direction due to transport using rolls such as transport rolls during manufacturing, so it is necessary to heat the film while applying tension only in the TD direction. In some cases, it is possible to obtain a support whose expansion or contraction during heating is suppressed.

When applying tension in the MD direction, a predetermined tension can be applied by adjusting the tension applied to a film made of a plastic material stretched between a plurality of rolls. In addition, applying tension in the TD direction can be carried out by any conventionally known suitable means. When applying tension in the TD direction, a predetermined tension can be applied using a tenter or the like having a conventionally known configuration.

Further, for example, a predetermined tension can be applied to the film made of plastic material in the MD direction or TD direction by using the weight and gravity of the weight. Specifically, one edge of the film made of plastic material in the direction to be adjusted is attached to a support rod, etc. so that the direction to be adjusted out of the TD direction and the MD direction coincides with the vertical direction. It is fixed with any suitable adhesive material (for example, Kapton adhesive tape, PTFE adhesive tape, glass cloth adhesive tape) and hung so that the entire film made of plastic material is under uniform tension. Thereafter, a weight such as a metal plate is connected by any suitable adhesive member so that tension is applied uniformly to the entire film made of plastic material at the opposite edge of the other side in the direction to be adjusted, and the weight of the weight is Preheating treatment can be performed by heating while applying tension.

The magnitude of the tension applied to the film made of plastic material can be set to any suitable tension, taking into account the material of the film made of plastic material, its expansion coefficient, the composition of the resin composition, etc. For example, the tension may be 3 gf/cm ² to 30 gf/cm ² .

In one embodiment, the heating temperature of the preheating treatment is preferably (Tg+50)°C or higher, more preferably (Tg+60)°C or higher, even more preferably (Tg+70), where Tg is the glass transition temperature of the film made of plastic material. )°C or higher, even more preferably (Tg+80)°C or higher or (Tg+90)°C or higher. The upper limit of the heating temperature is preferably (Tg + 115) °C or less, more preferably (Tg + 110) °C or less, even more preferably (Tg + 105) °C or less, as long as it is below the melting point of the film made of the plastic material.

When the support is, for example, a PET film, the heating temperature of the preheating treatment is preferably 130°C or higher, more preferably 140°C or higher, even more preferably 150°C or higher, and even more preferably 160°C or higher or 170°C. That's all. The upper limit of the heating temperature is preferably 195°C or lower, more preferably 190°C or lower, even more preferably 185°C or lower. The heating time of the preheating treatment is preferably 1 minute or more, more preferably 2 minutes or more, even more preferably 5 minutes or more, 10 minutes or more, or 15 minutes or more. The upper limit of the heating time depends on the heating temperature, but is preferably 120 minutes or less, more preferably 90 minutes or less, and still more preferably 60 minutes or less.

The atmosphere in which the preheating treatment is carried out is not particularly limited, and examples thereof include air atmosphere, inert gas atmosphere (nitrogen gas atmosphere, helium gas atmosphere, argon gas atmosphere, etc.), and the support can be easily prepared. From this point of view, an atmospheric atmosphere is preferred.

Although the preheating treatment may be carried out under reduced pressure, normal pressure, or increased pressure, it is preferably carried out under normal pressure from the viewpoint of easily preparing the support.

The surface of the support to be bonded to the resin composition layer may be subjected to matte treatment, corona treatment, or antistatic treatment.

Further, as the support, a support with a release layer having a release layer on the surface to be bonded to the resin composition layer may be used. Examples of the release agent used in the release layer of the support with a release layer include one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. . The support with a release layer may be a commercially available product, such as "SK-1" manufactured by Lintec Corporation, which is a PET film having a release layer containing an alkyd resin mold release agent as a main component. Examples include "AL-5", "AL-7", "Lumirror T60" manufactured by Toray Industries, "Purex" manufactured by Teijin, and "Unipeel" manufactured by Unitika.

<Resin composition layer>
The resin sheet has a resin composition layer containing a resin composition. The resin composition layer is usually bonded to the support. The resin composition is not particularly limited as long as its cured product has sufficient hardness and insulation properties. Examples of such resin compositions include compositions containing a curable resin and a curing agent thereof. As the curable resin, an epoxy resin used for forming an insulating layer of a printed wiring board is preferable. Thus, in one embodiment, the resin composition includes an epoxy resin and a curing agent. The resin composition may further contain an inorganic filler, a thermoplastic resin, a curing accelerator, and other additives, if necessary.

-Epoxy resin-
The resin composition contains an epoxy resin. Examples of the epoxy resin include bixylenol type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol type epoxy resin, Naphthol novolac type epoxy resin, phenol novolac type epoxy resin, tert-butyl-catechol type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, glycidylamine type epoxy resin, glycidyl ester type epoxy resin, cresol novolac type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin, epoxy resin with butadiene structure, alicyclic epoxy resin, heterocyclic epoxy resin, spiro ring-containing epoxy resin, cyclohexane type epoxy resin, cyclohexanedimethanol type Examples include epoxy resin, naphthylene ether type epoxy resin, trimethylol type epoxy resin, tetraphenylethane type epoxy resin, and the like. One type of epoxy resin may be used alone, or two or more types may be used in combination.

It is preferable that the resin composition contains, as the epoxy resin, an epoxy resin having two or more epoxy groups in one molecule. From the viewpoint of obtaining an insulating layer exhibiting good mechanical strength and insulation reliability, the proportion of epoxy resin having two or more epoxy groups in one molecule is preferably The content is 50% by mass or more, more preferably 60% by mass or more, particularly preferably 70% by mass or more.

Epoxy resins include epoxy resins that are liquid at a temperature of 20°C (hereinafter sometimes referred to as "liquid epoxy resins") and epoxy resins that are solid at a temperature of 20°C (hereinafter sometimes referred to as "solid epoxy resins"). ). The resin composition may contain only a liquid epoxy resin, only a solid epoxy resin, or a combination of a liquid epoxy resin and a solid epoxy resin.

As the solid epoxy resin, a solid epoxy resin having three or more epoxy groups in one molecule is preferable, and an aromatic solid epoxy resin having three or more epoxy groups in one molecule is more preferable.

Solid epoxy resins include bixylenol type epoxy resin, naphthalene type epoxy resin, naphthalene type tetrafunctional epoxy resin, cresol novolak type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol type epoxy resin, naphthol type epoxy resin, and biphenyl. Type epoxy resin, naphthylene ether type epoxy resin, anthracene type epoxy resin, bisphenol A type epoxy resin, bisphenol AF type epoxy resin, and tetraphenylethane type epoxy resin are preferable, and naphthalene type tetrafunctional epoxy resin and biphenyl type epoxy resin are more preferable. preferable.

Specific examples of solid epoxy resins include "HP4032H" (naphthalene type epoxy resin) manufactured by DIC; "HP-4700" and "HP-4710" (naphthalene type tetrafunctional epoxy resin) manufactured by DIC; “N-690” (cresol novolak type epoxy resin) manufactured by DIC; “N-695” (cresol novolac type epoxy resin) manufactured by DIC; “HP-7200”, “HP-7200HH”, “HP” manufactured by DIC -7200H" (dicyclopentadiene type epoxy resin); DIC's "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000" ( naphthylene ether type epoxy resin); "EPPN-502H" (trisphenol type epoxy resin) manufactured by Nippon Kayaku; "NC7000L" (naphthol novolac type epoxy resin) manufactured by Nippon Kayaku; "NC3000H", "NC3000", "NC3000L", "NC3100" (biphenyl type epoxy resin); "ESN475V" (naphthol type epoxy resin) manufactured by Nippon Steel & Sumikin Chemical; "ESN485" (naphthol novolac) manufactured by Nippon Steel & Sumikin Chemical type epoxy resin); “YX4000H”, “YX4000”, “YL6121” manufactured by Mitsubishi Chemical Company (biphenyl type epoxy resin); “YX4000HK” manufactured by Mitsubishi Chemical Company (bixylenol type epoxy resin); manufactured by Mitsubishi Chemical Company “ YX8800” (anthracene type epoxy resin); “PG-100”, “CG-500” manufactured by Osaka Gas Chemical Company; “YL7760” (bisphenol AF type epoxy resin) manufactured by Mitsubishi Chemical Company; “YL7800” manufactured by Mitsubishi Chemical Company " (fluorene type epoxy resin); "jER1010" (solid bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical; "jER1031S" (tetraphenylethane type epoxy resin) manufactured by Mitsubishi Chemical. These may be used alone or in combination of two or more.

As the liquid epoxy resin, a liquid epoxy resin having two or more epoxy groups in one molecule is preferable.

Liquid epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, phenol novolak type epoxy resin, and ester skeleton. Alicyclic epoxy resins, cyclohexane-type epoxy resins, cyclohexanedimethanol-type epoxy resins, glycidylamine-type epoxy resins, and epoxy resins having a butadiene structure are preferred, and bisphenol A-type epoxy resins are more preferred.

Specific examples of liquid epoxy resins include "HP4032", "HP4032D", "HP4032SS" (naphthalene type epoxy resin) manufactured by DIC; "828US", "jER828EL", "825", and "Epicoat" manufactured by Mitsubishi Chemical Corporation. 828EL" (bisphenol A type epoxy resin); "jER807", "1750" (bisphenol F type epoxy resin) manufactured by Mitsubishi Chemical; "jER152" (phenol novolac type epoxy resin) manufactured by Mitsubishi Chemical; manufactured by Mitsubishi Chemical “630” and “630LSD” (glycidylamine type epoxy resin); “ZX1059” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. (mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin); “EX” manufactured by Nagase ChemteX -721" (glycidyl ester type epoxy resin); Daicel's "Celoxide 2021P" (alicyclic epoxy resin with ester skeleton); Daicel's "PB-3600" (epoxy resin with butadiene structure); Nippon Steel Examples include "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane type epoxy resin) manufactured by Sumikin Chemical Co., Ltd. These may be used alone or in combination of two or more.

When using a combination of a liquid epoxy resin and a solid epoxy resin as the epoxy resin, their quantitative ratio (liquid epoxy resin: solid epoxy resin) is preferably 1:0.1 to 1:20 in terms of mass ratio, The ratio is more preferably 1:0.5 to 1:15, particularly preferably 1:1 to 1:10. When the ratio of the liquid epoxy resin to the solid epoxy resin is within this range, the desired effects of the present invention can be significantly obtained. Furthermore, when used in the form of a resin sheet, adequate tackiness is usually provided. Further, when used in the form of a resin sheet, sufficient flexibility is usually obtained and handling properties are improved. Furthermore, it is usually possible to obtain a cured product having sufficient breaking strength.

The epoxy equivalent of the epoxy resin is preferably 50 g/eq. ～5000g/eq. , more preferably 50g/eq. ～3000g/eq. , more preferably 80g/eq. ～2000g/eq. , even more preferably 110 g/eq. ～1000g/eq. It is. By falling within this range, the crosslinking density of the cured product of the resin composition layer will be sufficient, and an insulating layer with small surface roughness can be provided. Epoxy equivalent is the mass of epoxy resin containing one equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K7236.

The weight average molecular weight (Mw) of the epoxy resin is preferably from 100 to 5,000, more preferably from 250 to 3,000, even more preferably from 400 to 1,500, from the viewpoint of significantly obtaining the desired effects of the present invention.
The weight average molecular weight of the resin can be measured as a value in terms of polystyrene by gel permeation chromatography (GPC).

From the viewpoint of obtaining an insulating layer exhibiting good mechanical strength and insulation reliability, the content of the epoxy resin is preferably 5% by mass or more, more preferably The content is 10% by mass or more, more preferably 20% by mass or more. The upper limit of the content of the epoxy resin is preferably 50% by mass or less, more preferably 40% by mass or less, particularly preferably 35% by mass or less, from the viewpoint of significantly obtaining the desired effects of the present invention.
In the present invention, the content of each component in the resin composition is a value based on 100% by mass of nonvolatile components in the resin composition, unless otherwise specified.

-Hardening agent-
The resin composition contains a curing agent. A curing agent usually has the function of reacting with an epoxy resin and curing the resin composition. One type of curing agent may be used alone, or two or more types may be used in combination in any ratio.

As the curing agent, a compound capable of curing the resin composition by reacting with the epoxy resin can be used, such as active ester curing agents, phenol curing agents, naphthol curing agents, and benzoxazine curing agents. , carbodiimide-based curing agents, acid anhydride-based curing agents, amine-based curing agents, cyanate ester-based curing agents, and the like. Among these, phenolic curing agents and naphthol curing agents are preferred.

Specific examples of phenolic curing agents and naphthol curing agents include "MEH-7700", "MEH-7810", "MEH-7851", and "MEH-8000H" manufactured by Meiwa Kasei Co., Ltd.; and "MEH-8000H" manufactured by Nippon Kayaku Co., Ltd. "NHN", "CBN", "GPH"; "SN-170", "SN-180", "SN-190", "SN-475", "SN-485", "SN" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. -495", "SN-495V", "SN-375", "SN-395"; DIC's "TD-2090", "TD-2090-60M", "LA-7052", "LA-7054" ", "LA-1356", "LA-3018", "LA-3018-50P", "EXB-9500", "HPC-9500", "KA-1160", "KA-1163", "KA-1165 "; Examples include "GDP-6115L", "GDP-6115H", and "ELPC75" manufactured by Gunei Chemical Co., Ltd.

Examples of active ester curing agents include curing agents having one or more active ester groups in one molecule. Among these, active ester curing agents include those containing two or more ester groups with high reaction activity in one molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds. Compounds having the following are preferred. The active ester curing agent is preferably one obtained by a condensation reaction between a carboxylic acid compound and/or a thiocarboxylic acid compound and a hydroxy compound and/or a thiol compound. In particular, from the viewpoint of improving heat resistance, active ester curing agents obtained from a carboxylic acid compound and a hydroxy compound are preferred, and active ester curing agents obtained from a carboxylic acid compound and a phenol compound and/or a naphthol compound are more preferred. .

Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid.

Examples of phenolic compounds or naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalin, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m- Cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, Examples include benzenetriol, dicyclopentadiene type diphenol compounds, and phenol novolacs. Here, the term "dicyclopentadiene type diphenol compound" refers to a diphenol compound obtained by condensing two molecules of phenol with one molecule of dicyclopentadiene.

Preferred specific examples of the active ester curing agent include an active ester compound containing a dicyclopentadiene type diphenol structure, an active ester compound containing a naphthalene structure, an active ester compound containing an acetylated product of phenol novolak, and a benzoylated product of phenol novolac. Examples include active ester compounds containing. Among these, active ester compounds containing a naphthalene structure and active ester compounds containing a dicyclopentadiene type diphenol structure are more preferable. "Dicyclopentadiene type diphenol structure" refers to a divalent structure consisting of phenylene-dicyclopentylene-phenylene.

Commercially available active ester curing agents include "EXB9451", "EXB9460", "EXB9460S", "HPC-8000", "HPC-8000H", " HPC-8000-65T”, “HPC-8000H-65TM”, “HPC-8150-62T”, “EXB-8000L”, “EXB-8000L-65TM”, “EXB-8150-65T” (manufactured by DIC); "EXB-8100L-65T", "EXB-8150L-65T", "EXB9416-70BK" (manufactured by DIC Corporation) as active ester compounds containing a naphthalene structure; "DC808" as an active ester compound containing an acetylated product of phenol novolak ( "YLH1026" (manufactured by Mitsubishi Chemical) as an active ester compound containing a benzoylated phenol novolak; "DC808" (manufactured by Mitsubishi Chemical) as an active ester curing agent that is an acetylated phenol novolak; Examples of active ester curing agents that are benzoylated products of phenol novolak include "YLH1026" (manufactured by Mitsubishi Chemical Corporation), "YLH1030" (manufactured by Mitsubishi Chemical Corporation), and "YLH1048" (manufactured by Mitsubishi Chemical Corporation).

Examples of the phenolic curing agent include curing agents having one or more, preferably two or more, hydroxyl groups bonded to an aromatic ring (benzene ring, naphthalene ring, etc.) in one molecule. Among these, compounds having a hydroxyl group bonded to a benzene ring are preferred. Moreover, from the viewpoint of heat resistance and water resistance, a phenolic curing agent having a novolak structure is preferable. Furthermore, from the viewpoint of adhesion, nitrogen-containing phenolic curing agents are preferred, and triazine skeleton-containing phenolic curing agents are more preferred. In particular, from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion, a triazine skeleton-containing phenol novolak curing agent is preferred.

Specific examples of benzoxazine curing agents include "HFB2006M" manufactured by Showa Kobunshi Co., Ltd., and "Pd" and "Fa" manufactured by Shikoku Kasei Kogyo Co., Ltd.

Specific examples of the carbodiimide curing agent include "V-03", "V-05", and "V-07" manufactured by Nisshinbo Chemical Co., Ltd.; Stabaxol (registered trademark) P manufactured by Rhein Chemie Co., Ltd., and the like.

Examples of acid anhydride curing agents include curing agents having one or more acid anhydride groups in one molecule. Specific examples of acid anhydride curing agents include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, methylhexahydrophthalic anhydride, and methylnasic. Acid anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenylsuccinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1, 2-dicarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, bensophenonetetracarboxylic dianhydride, biphenyltetracarboxylic dianhydride, naphthalenetetracarboxylic dianhydride, oxydiphthalic dianhydride, 3 , 3'-4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[ Examples include polymeric acid anhydrides such as 1,2-C]furan-1,3-dione, ethylene glycol bis(anhydrotrimellitate), and styrene-maleic acid resin, which is a copolymer of styrene and maleic acid. It will be done. A commercially available acid anhydride curing agent may be used, such as "MH-700" manufactured by Shin Nihon Rika Co., Ltd., for example.

Examples of the amine curing agent include curing agents having one or more amino groups in one molecule, such as aliphatic amines, polyether amines, alicyclic amines, aromatic amines, etc. Among them, aromatic amines are preferred from the viewpoint of achieving the desired effects of the present invention. The amine curing agent is preferably a primary amine or a secondary amine, and more preferably a primary amine. Specific examples of the amine curing agent include 4,4'-methylenebis(2,6-dimethylaniline), diphenyldiaminosulfone, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, and 3,3' - Diaminodiphenylsulfone, m-phenylenediamine, m-xylylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl- 4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, 2,2-bis(3-amino-4-hydroxyphenyl)propane, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethane Diamine, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 1,3-bis(3-aminophenoxy)benzene, 1,3- Bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy)phenyl)sulfone, Examples include bis(4-(3-aminophenoxy)phenyl)sulfone. Commercially available amine curing agents may be used, such as "KAYABOND C-200S", "KAYABOND C-100", "KAYA HARD AA", "KAYA HARD AB", and "KAYABOND C-100" manufactured by Nippon Kayaku Co., Ltd. Examples include "Kayahard AS" and "Epicure W" manufactured by Mitsubishi Chemical Corporation.

Examples of cyanate ester curing agents include bisphenol A dicyanate, polyphenol cyanate, oligo(3-methylene-1,5-phenylene cyanate), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4 '-Ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate) phenylpropane, 1,1-bis(4-cyanate phenylmethane), bis(4-cyanate-3,5-dimethyl Bifunctional cyanate resins such as phenyl)methane, 1,3-bis(4-cyanatophenyl-1-(methylethylidene))benzene, bis(4-cyanatophenyl)thioether, and bis(4-cyanatophenyl)ether; Polyfunctional cyanate resins derived from phenol novolacs, cresol novolaks, etc.; prepolymers in which these cyanate resins are partially triazinized; and the like. Specific examples of cyanate ester curing agents include "PT30" and "PT60" (both phenol novolak type polyfunctional cyanate ester resins) manufactured by Lonza Japan; "ULL-950S" (polyfunctional cyanate ester resin); BA230'', ``BA230S75'' (a prepolymer in which part or all of bisphenol A dicyanate is triazinated to form a trimer); and the like.

From the viewpoint of significantly obtaining the effects of the present invention, the content of the curing agent is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably The content is 5% by mass or more, preferably 40% by mass or less, more preferably 35% by mass or less, even more preferably 30% by mass or less.

When the number of epoxy groups in the epoxy resin is 1, the number of active groups in the curing agent is preferably 0.1 or more, more preferably 0.2 or more, even more preferably 0.3 or more, and preferably 2 or less, more preferably is 1.8 or less, more preferably 1.6 or less, particularly preferably 1.4 or less. Here, "the number of epoxy groups in the epoxy resin" is the sum of all the values obtained by dividing the mass of nonvolatile components of the epoxy resin present in the resin composition by the epoxy equivalent. Moreover, "the number of active groups of a curing agent" is the total value of all the values obtained by dividing the mass of nonvolatile components of the curing agent present in the resin composition by the active group equivalent. When the number of active groups of the curing agent is within the above range when the number of epoxy groups in the epoxy is 1, the desired effects of the present invention can be significantly obtained.

-Inorganic filler-
The resin composition may contain an inorganic filler as an optional component. An inorganic compound is used as the material for the inorganic filler. Examples of inorganic filler materials include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum hydroxide, Magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide , barium titanate, barium zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among these, silica is particularly suitable. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. Further, as the silica, spherical silica is preferable. One type of inorganic filler may be used alone, or two or more types may be used in combination.

Commercially available inorganic fillers include, for example, "UFP-30" manufactured by Denka Kagaku Kogyo; "SP60-05" and "SP507-05" manufactured by Nippon Steel & Sumikin Materials; and "YC100C" manufactured by Admatex. , "YA050C", "YA050C-MJE", "YA010C"; "UFP-30" manufactured by Denka; "Silfill NSS-3N", "Silfill NSS-4N", "Silfill NSS-5N" manufactured by Tokuyama; Examples include "SC2500SQ", "SO-C4", "SO-C2", "SO-C1", and "SC2050-SXF" manufactured by Admatex.

The average particle size of the inorganic filler is preferably 0.01 μm or more, more preferably 0.05 μm or more, particularly preferably 0.1 μm or more, and preferably 5 μm, from the viewpoint of significantly obtaining the desired effects of the present invention. The thickness is more preferably 2 μm or less, and even more preferably 1 μm or less.

The average particle size of the inorganic filler can be measured by a laser diffraction/scattering method based on Mie scattering theory. Specifically, it can be measured by creating the particle size distribution of the inorganic filler on a volume basis using a laser diffraction scattering type particle size distribution measuring device, and using the median diameter as the average particle size. The measurement sample can be obtained by weighing 100 mg of the inorganic filler and 10 g of methyl ethyl ketone into a vial and dispersing them using ultrasonic waves for 10 minutes. The measurement sample was measured using a laser diffraction particle size distribution measuring device using a light source wavelength of blue and red, and the volume-based particle size distribution of the inorganic filler was measured using a flow cell method. The average particle size is calculated as the median diameter. Examples of the laser diffraction particle size distribution measuring device include "LA-960" manufactured by Horiba, Ltd.

The specific surface area of the inorganic filler is preferably 1 m ² /g or more, more preferably 2 m ² /g or more, particularly preferably 3 m ² /g or more, from the viewpoint of significantly obtaining the desired effects of the present invention. Although there is no particular limit to the upper limit, it is preferably 60 m ² /g or less, 50 m ² /g or less, or 40 m ² /g or less. The specific surface area is determined by adsorbing nitrogen gas onto the sample surface using a BET fully automatic specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech), and calculating the specific surface area using the BET multi-point method. It can be obtained by measuring the specific surface area of the material.

The inorganic filler is preferably treated with a surface treatment agent from the viewpoint of improving moisture resistance and dispersibility. Examples of surface treatment agents include fluorine-containing silane coupling agents, aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, alkoxysilanes, organosilazane compounds, and titanate-based coupling agents. Coupling agents and the like can be mentioned. Moreover, one type of surface treatment agent may be used alone, or two or more types may be used in any combination.

Commercially available surface treatment agents include, for example, "KBM403" (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM803" (3-mercaptopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd. "KBE903" (3-aminopropyltriethoxysilane) manufactured by Kagaku Kogyo, "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical, "SZ-31" manufactured by Shin-Etsu Chemical ( hexamethyldisilazane), "KBM103" (phenyltrimethoxysilane) manufactured by Shin-Etsu Chemical, "KBM-4803" (long chain epoxy type silane coupling agent) manufactured by Shin-Etsu Chemical, "KBM-" manufactured by Shin-Etsu Chemical 7103'' (3,3,3-trifluoropropyltrimethoxysilane).

The degree of surface treatment with the surface treatment agent is preferably within a predetermined range from the viewpoint of improving the dispersibility of the inorganic filler. Specifically, 100 parts by mass of the inorganic filler is preferably surface-treated with 0.2 parts by mass to 5 parts by mass of a surface treatment agent, and preferably 0.2 parts by mass to 3 parts by mass. Preferably, the surface treatment is carried out in an amount of 0.3 parts by mass to 2 parts by mass.

The degree of surface treatment by the surface treatment agent can be evaluated by the amount of carbon per unit surface area of the inorganic filler. The amount of carbon per unit surface area of the inorganic filler is preferably 0.02 mg/m ² or more, more preferably 0.1 mg/m ² or more, and 0.2 mg/m ² from the viewpoint of improving the dispersibility of the inorganic filler. The above is more preferable. On the other hand, from the viewpoint of suppressing an increase in the minimum melt viscosity of the resin varnish and the minimum melt viscosity in sheet form, it is preferably 1 mg/m ² or less, more preferably 0.8 mg/m ² or less, and 0.5 mg/m ² or less. is even more preferable.

The amount of carbon per unit surface area of the inorganic filler can be measured after the surface-treated inorganic filler is washed with a solvent (for example, methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the inorganic filler whose surface has been treated with a surface treatment agent, and the mixture is subjected to ultrasonic cleaning at 25° C. for 5 minutes. After removing the supernatant liquid and drying the solid content, the amount of carbon per unit surface area of the inorganic filler can be measured using a carbon analyzer. As the carbon analyzer, "EMIA-320V" manufactured by Horiba, Ltd., etc. can be used.

From the viewpoint of significantly obtaining the effects of the present invention, the content of the inorganic filler is preferably 10% by mass or more, more preferably 20% by mass or more, when the nonvolatile component in the resin composition is 100% by mass, More preferably, it is 30% by mass or more, preferably 90% by mass or less, more preferably 85% by mass or less, even more preferably 80% by mass or less.

-Thermoplastic resin-
The resin composition may contain a thermoplastic resin as an optional component. Examples of thermoplastic resins include phenoxy resin, polyvinyl acetal resin, polyolefin resin, polybutadiene resin, polyimide resin, polyamideimide resin, polyetherimide resin, polysulfone resin, polyether sulfone resin, polyphenylene ether resin, polycarbonate resin, and polyether. Examples include ether ketone resin and polyester resin. Among these, phenoxy resins are preferred from the viewpoint of significantly obtaining the desired effects of the present invention. Moreover, one type of thermoplastic resin may be used alone, or two or more types may be used in combination.

Examples of phenoxy resins include bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenolacetophenone skeleton, novolac skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton, anthracene skeleton, adamantane skeleton, and terpene. Examples include phenoxy resins having one or more types of skeletons selected from the group consisting of a skeleton and a trimethylcyclohexane skeleton. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group.

Specific examples of phenoxy resins include "1256" and "4250" manufactured by Mitsubishi Chemical Corporation (both phenoxy resins containing bisphenol A skeleton); "YX8100" manufactured by Mitsubishi Chemical Corporation (phenoxy resin containing bisphenol S skeleton); "YX6954" (phenoxy resin containing bisphenolacetophenone skeleton) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.; "FX280" and "FX293" manufactured by Nippon Steel & Sumikin Chemical; "YL7500BH30", "YX6954BH30", "YX7553", "YX7553BH30" manufactured by Mitsubishi Chemical Corporation, Examples include "YL7769BH30," "YL6794," "YL7213," "YL7290," and "YL7482."

Examples of the polyvinyl acetal resin include polyvinyl formal resin and polyvinyl butyral resin, with polyvinyl butyral resin being preferred. Specific examples of polyvinyl acetal resin include Denka Butyral 4000-2, Denka Butyral 5000-A, Denka Butyral 6000-C, and Denka Butyral 6000-EP manufactured by Denki Kagaku Kogyo; Sekisui Chemical Co., Ltd. Examples include the S-LEC BH series, BX series (for example, BX-5Z), KS series (for example, KS-1), BL series, and BM series manufactured by the company.

Specific examples of the polyimide resin include "Ricacoat SN20" and "Ricacoat PN20" manufactured by Shin Nihon Rika Co., Ltd. Specific examples of polyimide resins include linear polyimides obtained by reacting bifunctional hydroxyl group-terminated polybutadiene, diisocyanate compounds, and tetrabasic acid anhydrides (polyimide described in JP-A No. 2006-37083), polysiloxane skeletons, etc. Examples include modified polyimides such as polyimides containing polyimides (polyimides described in JP-A-2002-12667 and JP-A-2000-319386, etc.).

Specific examples of the polyamide-imide resin include "Viromax HR11NN" and "Viromax HR16NN" manufactured by Toyobo. Specific examples of polyamide-imide resins include modified polyamide-imides such as "KS9100" and "KS9300" (polysiloxane skeleton-containing polyamide-imide) manufactured by Hitachi Chemical.

A specific example of the polyether sulfone resin includes "PES5003P" manufactured by Sumitomo Chemical Co., Ltd.

Specific examples of the polyphenylene ether resin include oligophenylene ether styrene resin "OPE-2St 1200" manufactured by Mitsubishi Gas Chemical Co., Ltd.

Specific examples of the polysulfone resin include polysulfone "P1700" and "P3500" manufactured by Solvay Advanced Polymers.

The weight average molecular weight (Mw) of the thermoplastic resin is preferably 8,000 or more, more preferably 10,000 or more, particularly preferably 20,000 or more, from the viewpoint of significantly obtaining the desired effects of the present invention. Preferably it is 70,000 or less, more preferably 60,000 or less, particularly preferably 50,000 or less.

From the viewpoint of significantly obtaining the desired effects of the present invention, the content of the thermoplastic resin is preferably 0.1% by mass or more, more preferably 0.1% by mass or more, when the nonvolatile component in the resin composition is 100% by mass. The content is 2% by mass or more, more preferably 0.3% by mass or more, preferably 25% by mass or less, more preferably 20% by mass or less, even more preferably 15% by mass or less.

-Curing accelerator-
The resin composition may contain a curing accelerator as an optional component. Examples of the curing accelerator include phosphorus-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, guanidine-based curing accelerators, metal-based curing accelerators, and the like. One type of curing accelerator may be used alone, or two or more types may be used in combination.

Examples of the phosphorus curing accelerator include triphenylphosphine, phosphonium borate compounds, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl)triphenylphosphonium thiocyanate. , tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate and the like, with triphenylphosphine and tetrabutylphosphonium decanoate being preferred.

Examples of the amine curing accelerator include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo. Examples include (5,4,0)-undecene, and 4-dimethylaminopyridine and 1,8-diazabicyclo(5,4,0)-undecene are preferred.

Examples of imidazole-based curing accelerators include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl- 2-Phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecyl imidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4- Diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2- Phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline , 2-phenylimidazoline and other imidazole compounds, and adducts of imidazole compounds and epoxy resins, with 2-ethyl-4-methylimidazole and 1-benzyl-2-phenylimidazole being preferred.

As the imidazole curing accelerator, commercially available products may be used, such as "P200-H50" manufactured by Mitsubishi Chemical Corporation.

Examples of the guanidine-based curing accelerator include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, Tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0] Dec-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1 -allylbiguanide, 1-phenylbiguanide, 1-(o-tolyl)biguanide, etc., and dicyandiamide and 1,5,7-triazabicyclo[4.4.0]dec-5-ene are preferred.

Examples of the metal hardening accelerator include organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organometallic complexes include organic cobalt complexes such as cobalt (II) acetylacetonate and cobalt (III) acetylacetonate, organic copper complexes such as copper (II) acetylacetonate, and zinc (II) acetylacetonate. Examples include organic zinc complexes such as , organic iron complexes such as iron (III) acetylacetonate, organic nickel complexes such as nickel (II) acetylacetonate, and organic manganese complexes such as manganese (II) acetylacetonate. Examples of the organic metal salt include zinc octylate, tin octylate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

From the viewpoint of significantly obtaining the desired effects of the present invention, the content of the curing accelerator is preferably 0.01% by mass or more, more preferably 0.01% by mass or more, when the nonvolatile component in the resin composition is 100% by mass. 0.03% by mass or more, more preferably 0.05% by mass or more, preferably 1% by mass or less, more preferably 0.5% by mass or less, even more preferably 0.1% by mass or less.

-Other additives-
In addition to the above-mentioned components, the resin composition may further contain other additives as optional components. Examples of such additives include resin additives such as thickeners, antifoaming agents, leveling agents, and adhesion agents. These additives may be used alone or in combination of two or more. The content of each can be set as appropriate by those skilled in the art.

The method for preparing the resin composition of the present invention is not particularly limited, and includes, for example, a method in which the ingredients are mixed and dispersed using a rotary mixer or the like, adding a solvent or the like if necessary.

<Other layers>
The resin sheet may include other layers as necessary. Examples of such other layers include, for example, a protective film similar to the support provided on the surface of the resin composition layer that is not bonded to the support (i.e., the surface opposite to the support). It will be done. The thickness of the protective film is not particularly limited, but is, for example, 1 μm to 40 μm. By laminating the protective film, adhesion of dust and the like to the surface of the resin composition layer and scratches can be suppressed.

[Rolled resin sheet]
The resin sheet can be stored by winding it up into a roll. The resin sheet is as described above.

[Method for manufacturing resin sheet]
The resin sheet can be manufactured, for example, by a manufacturing method that includes applying a resin composition to areas other than the margins of the support. The support and the resin composition are as described above. Therefore, for example, the resin sheet 1 shown in FIG. 1 can be manufactured by a manufacturing method that includes applying a resin composition to a portion of the support 2 other than the margin portion 4.

In detail, the resin sheet is prepared by, for example, preparing a resin varnish by dissolving a resin composition in an organic solvent, and applying this resin varnish to areas other than the margins on the support using a coating device such as a die coater. It can be manufactured by coating and drying as necessary to form a resin composition layer.

Examples of organic solvents include ketones such as acetone, methyl ethyl ketone (MEK), and cyclohexanone; acetate esters such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; cellosolve and butyl carbitol, etc. carbitols; aromatic hydrocarbons such as toluene and xylene; and amide solvents such as dimethylformamide, dimethylacetamide (DMAc) and N-methylpyrrolidone. One type of organic solvent may be used alone, or two or more types may be used in combination.

Drying may be performed by a known method such as heating or blowing hot air. Although drying conditions are not particularly limited, drying is performed so that the content of organic solvent in the resin composition layer is 10% by mass or less, preferably 5% by mass or less. Although it varies depending on the boiling point of the organic solvent in the resin varnish, for example, when using a resin varnish containing 30% to 60% by mass of organic solvent, the resin composition can be adjusted by drying at 50°C to 150°C for 3 to 10 minutes. A material layer can be formed.

[Printed wiring board, printed wiring board manufacturing method]
The printed wiring board of the present invention includes an insulating layer formed of a cured product of the resin composition layer of the resin sheet or rolled resin sheet of the present invention.

The printed wiring board uses the resin sheet of the present invention,
(A) A first resin sheet including a first support and a first resin composition layer provided on the first support, and the first resin composition layer is an inner layer substrate. (B) a step of thermally curing the resin composition layer to form an insulating layer;
(C) a step of removing the support; and (D) a second resin sheet including a second support and a second resin composition layer provided on the second support; Laminating a second resin composition layer on the insulating layer toward the insulating layer side, thermosetting the second resin composition layer, and removing the second support;
in this order, and step (D) can be produced by repeating the process two or more times.

In the method for manufacturing a printed wiring board, step (D) is repeated two or more times to form a multi-layered insulating layer of three or more layers. Conventionally, when forming an insulating layer, the bleed-out resin composition rose slightly near the edge of the support, and this rise was amplified by multi-layer stacking of three or more layers, causing undulation. . In contrast, in the printed wiring board manufacturing method of the present invention, by forming an insulating layer using the resin sheet of the present invention, the insulating layer that is formed even if the insulating layer is laminated in multiple stages of three or more layers. This makes it possible to suppress the occurrence of undulation. Moreover, the method for manufacturing a printed wiring board may include other steps. For example, the step (E), step (F), and step (G) described below may be included. Any steps such as steps (E) to (G) may be performed between step (C) and step (D), or may be performed between step (D) and another step (D). It's okay.

The number of times step (D) is repeated is 2 or more times, preferably 3 or more times, more preferably 4 or more times, even more preferably 5 or more times, and preferably 50 or less times, more preferably 30 or less times. , more preferably 20 times or less.

Hereinafter, the above-mentioned steps for manufacturing a printed wiring board will be explained in detail. In the following explanation, in order to distinguish between the resin sheet used in step (A) and the resin sheet used in step (D), numbers may be attached to the resin sheet and the elements included in the resin sheet. . For example, the resin sheet used in step (A) is called a "first resin sheet," and the support, resin composition layer, and blank space contained therein are called the "first support" and "first resin sheet," respectively. "resin composition layer" and "first margin". In addition, the resin sheet used in step (D) is referred to as a "second resin sheet," and the support, resin composition layer, and blank area contained therein are referred to as the "second support" and "second resin sheet," respectively. "resin composition layer" and "second margin".

<Process (A)>
In step (A), a first resin sheet including a first support and a first resin composition layer provided on the first support is coated with a first resin composition layer. is laminated on the inner layer substrate so that the material is bonded to the inner layer substrate. The first resin sheet used in step (A) is as described above.

The "inner layer substrate" used in step (A) is a member that becomes the substrate of a printed wiring board, and includes, for example, a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, and a thermosetting polyphenylene ether substrate. etc. Further, the substrate may have a conductor layer on one or both sides, and this conductor layer may be patterned. An inner layer board in which a conductor layer (circuit) is formed on one or both sides of the board is sometimes referred to as an "inner layer circuit board." Further, when manufacturing a printed wiring board, an intermediate product on which an insulating layer and/or a conductive layer is further formed is also included in the "inner layer substrate" as referred to in the present invention. When the printed wiring board is a circuit board with built-in components, an inner layer board with built-in components can be used.

The bonding (lamination) of the inner layer substrate and the first resin sheet can be performed, for example, by heat-pressing the first resin sheet to the inner layer substrate from the first support side. Examples of the member for heat-pressing the first resin sheet to the inner layer substrate (hereinafter also referred to as "heat-pressing member") include a heated metal plate (SUS mirror plate, etc.) or a metal roll (SUS roll). It will be done. Note that instead of pressing the thermocompression bonding member directly onto the first resin sheet, it is preferable to press it through an elastic material such as heat-resistant rubber so that the first resin sheet sufficiently follows the surface irregularities of the inner layer substrate. preferable.

The inner layer substrate and the first resin sheet may be laminated by a vacuum lamination method. In the vacuum lamination method, the heat-pressing temperature is preferably in the range of 60°C to 160°C, more preferably 80°C to 140°C, and the heat-pressing pressure is preferably in the range of 0.098 MPa to 1.77 MPa, more preferably 0. The pressure is in the range of .29 MPa to 1.47 MPa, and the heat-pressing time is preferably in the range of 20 seconds to 400 seconds, more preferably 30 seconds to 300 seconds. Lamination is preferably carried out under reduced pressure conditions of 26.7 hPa or less.

Lamination can be performed using a commercially available vacuum laminator. Examples of commercially available vacuum laminators include a vacuum pressure laminator manufactured by Meiki Seisakusho, a vacuum applicator manufactured by Nikko Materials, and a batch vacuum pressure laminator.

After lamination, the laminated first resin sheets may be smoothed under normal pressure (atmospheric pressure), for example, by pressing a thermocompression bonding member from the support side. The pressing conditions for the smoothing treatment can be the same as the conditions for the heat-pressing of the lamination described above. The smoothing process can be performed using a commercially available laminator. Note that the lamination and smoothing treatment may be performed continuously using the above-mentioned commercially available vacuum laminator.

<Process (B)>
In step (B), the first resin composition layer is thermally cured to form an insulating layer. The heat curing conditions for the first resin composition layer vary depending on the type of resin composition, etc., but the curing temperature is preferably 120°C to 240°C, more preferably 150°C to 220°C, even more preferably 170°C to The temperature is 210°C. The curing time can be preferably 5 minutes to 120 minutes, more preferably 10 minutes to 100 minutes, even more preferably 15 minutes to 100 minutes.

Before thermally curing the first resin composition layer, the first resin composition layer may be preheated at a temperature lower than the curing temperature. For example, prior to thermosetting the first resin composition layer, the first The resin composition layer may be preheated for 5 minutes or more (preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, still more preferably 15 minutes to 100 minutes).

<Step (C)>
In step (C), the first support is removed.

The first support can be removed by any conventionally known suitable method, and may be mechanically removed by an automatic peeling device. By performing this step (C), the surface of the formed insulating layer is exposed.

<Step (D)>
In the step (D), a second resin sheet is laminated on the insulating layer with the second resin composition layer facing the insulating layer side, the second resin composition layer is thermoset, and the second resin sheet is laminated on the insulating layer. remove the body. At this time, an arbitrary layer such as a conductor layer may be provided between the insulating layer and the second resin composition layer. By performing step (D), the second resin composition layer is cured and another insulating layer is further obtained, so it becomes possible to stack the insulating layers in multiple stages. The second resin sheet used in step (D) is the resin sheet of the present invention, as described above. The second resin sheet may be the same as or different from the first resin sheet. Moreover, when repeating step (D) twice or more, the second resin sheets used in each step (D) may be the same or different.

The bonding (lamination) of the insulating layer and the second resin sheet in step (D) is the same as the bonding of the inner layer substrate and the first resin sheet in step (A). Further, the thermosetting conditions for the second resin composition layer are the same as those for the first resin composition layer in step (B). Furthermore, removal of the second support can be performed in the same manner as the first support. Step (D) is repeated two or more times, preferably three or more times, more preferably four or more times, particularly preferably five or more times.

The above step (D) includes the step (A) to the end portion of the insulating layer formed by the step (C), and the second resin sheet laminated on the insulating layer in the step (D). It is preferable to carry out the process so that the ends of the resin composition layer substantially overlap with each other. Specifically, the distance between the end of the insulating layer formed from step (A) to step (C) and the end of the second resin composition layer laminated in step (D) is in the thickness direction. Preferably, it is within a specific range. Said range is preferably from 0 to 10 mm, more preferably from 0 to 5 mm, particularly preferably from 0 to 3 mm. In such cases, with conventional techniques, undulations tend to become particularly large. However, according to the manufacturing method of the present invention, even when multi-stage lamination is performed such that the end of the insulating layer and the end of the second resin composition layer substantially overlap, the undulation can be effectively prevented. Suppression is possible.

<Other processes>
When manufacturing a printed wiring board, further steps are performed: step (E) drilling holes in the insulating layer, step (F) roughening the insulating layer, and step (G) forming a conductor layer on the surface of the insulating layer. You may. These steps (E) to (G) may be performed according to various methods used in the manufacture of printed wiring boards and known to those skilled in the art.

Further, the steps (E) to (G) may be carried out between the steps (C) and (D), and may be carried out repeatedly. The number of times that steps (E) to (G) are repeated is the same as the number of times that steps (C) to (D) are repeated.

Step (E) is a step of drilling a hole in the insulating layer, whereby via holes and through holes can be formed in the insulating layer. The step of drilling can be performed using, for example, a drill, laser (carbon dioxide laser, YAG laser, etc.), plasma, or the like.

Step (F) is a step of roughening the insulating layer. Usually, in this step (F), smear is also removed. The procedure and conditions for the roughening treatment are not particularly limited, and known procedures and conditions commonly used in forming an insulating layer of a printed wiring board can be adopted. For example, the insulating layer can be roughened by performing a swelling treatment using a swelling liquid, a roughening treatment using an oxidizing agent, and a neutralization treatment using a neutralizing liquid in this order. The swelling liquid used in the roughening treatment is not particularly limited, but includes alkaline solutions, surfactant solutions, etc., preferably alkaline solutions, and more preferably sodium hydroxide solutions and potassium hydroxide solutions. preferable. Examples of commercially available swelling liquids include "Swelling Dip Securigance P", "Swelling Dip Securigance SBU", and "Swelling Dip Securigant P" manufactured by Atotech Japan. It will be done. Swelling treatment with a swelling liquid is not particularly limited, but can be carried out, for example, by immersing the insulating layer in a swelling liquid at 30° C. to 90° C. for 1 minute to 20 minutes. From the viewpoint of suppressing the swelling of the resin in the insulating layer to an appropriate level, it is preferable to immerse the insulating layer in a swelling liquid at 40° C. to 80° C. for 5 minutes to 15 minutes. The oxidizing agent used in the roughening treatment is not particularly limited, but includes, for example, an alkaline permanganate solution in which potassium permanganate or sodium permanganate is dissolved in an aqueous solution of sodium hydroxide. The roughening treatment with an oxidizing agent such as an alkaline permanganic acid solution is preferably performed by immersing the insulating layer in an oxidizing agent solution heated to 60° C. to 100° C. for 10 minutes to 30 minutes. Further, the concentration of permanganate in the alkaline permanganic acid solution is preferably 5% by mass to 10% by mass. Examples of commercially available oxidizing agents include alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securigance P" manufactured by Atotech Japan. Further, as the neutralizing liquid used for the roughening treatment, an acidic aqueous solution is preferable, and a commercially available product includes, for example, "Reduction Solution Securigant P" manufactured by Atotech Japan. The treatment with the neutralizing liquid can be carried out by immersing the treated surface, which has been roughened with an oxidizing agent, in the neutralizing liquid at 30° C. to 80° C. for 1 minute to 30 minutes. From the viewpoint of workability, it is preferable to immerse the object that has been roughened with an oxidizing agent in a neutralizing solution at 40° C. to 70° C. for 5 minutes to 20 minutes.

In one embodiment, the arithmetic mean roughness (Ra) of the surface of the insulating layer after the roughening treatment is preferably 300 nm or less, more preferably 250 nm or less, and still more preferably 200 nm or less. The lower limit is not particularly limited, but is preferably 30 nm or more, more preferably 40 nm or more, and still more preferably 50 nm or more. The arithmetic mean roughness (Ra) of the surface of the insulating layer can be measured using a non-contact surface roughness meter.

Step (G) is a step of forming a conductor layer, and the conductor layer is formed on the insulating layer. The conductor material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer includes one or more selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. Contains metal. The conductor layer may be a single metal layer or an alloy layer, and the alloy layer may be, for example, an alloy of two or more metals selected from the above group (for example, a nickel-chromium alloy, a copper-chromium alloy, a copper-chromium alloy, etc.). nickel alloys and copper-titanium alloys). Among these, from the viewpoint of versatility in forming conductor layers, cost, ease of patterning, etc., monometallic layers of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, nickel-chromium alloys, copper, etc. An alloy layer of nickel alloy or copper/titanium alloy is preferable, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or an alloy layer of nickel/chromium alloy is more preferable, and a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper is more preferable. More preferred is a metal layer.

The conductor layer may have a single layer structure or a multilayer structure in which two or more single metal layers or alloy layers made of different types of metals or alloys are laminated. When the conductor layer has a multilayer structure, the layer in contact with the insulating layer is preferably a single metal layer of chromium, zinc, or titanium, or an alloy layer of nickel-chromium alloy.

The thickness of the conductor layer depends on the desired printed wiring board design, but is generally between 3 μm and 35 μm, preferably between 5 μm and 30 μm.

In one embodiment, the conductor layer may be formed by plating. For example, a conductor layer having a desired wiring pattern can be formed by plating the surface of an insulating layer using a conventionally known technique such as a semi-additive method or a fully additive method. It is preferable to form by a method. An example of forming a conductor layer by a semi-additive method will be shown below.

First, a plating seed layer is formed on the surface of the insulating layer by electroless plating. Next, a mask pattern is formed on the formed plating seed layer to expose a portion of the plating seed layer corresponding to a desired wiring pattern. After forming a metal layer on the exposed plating seed layer by electrolytic plating, the mask pattern is removed. Thereafter, unnecessary plating seed layers can be removed by etching or the like to form a conductor layer having a desired wiring pattern.

In the method for manufacturing a printed wiring board of the present invention, the printed wiring board may be manufactured using the rolled resin sheet of the present invention instead of the resin sheet.

According to the manufacturing method described above, it is possible to obtain a printed wiring board including an insulating layer in which undulation is suppressed even when stacked in multiple stages. The undulation of the insulating layer of the printed wiring board manufactured by the above manufacturing method is preferably 2 μm or less, more preferably 1.5 μm or less, particularly preferably 1 μm or less. The lower limit is not particularly limited, but may be 0 μm or more.

[Semiconductor device]
Using the printed wiring board obtained by the manufacturing method of the present invention, a semiconductor device including such a printed wiring board can be manufactured.

Examples of semiconductor devices include various semiconductor devices used in electrical products (e.g., computers, mobile phones, digital cameras, televisions, etc.) and vehicles (e.g., motorcycles, automobiles, trains, ships, aircraft, etc.). It will be done.

Hereinafter, the present invention will be specifically explained with reference to Examples. The present invention is not limited to these examples. In the following, "parts" and "%" mean "parts by mass" and "% by mass", respectively, unless otherwise specified.

<Measurement of minimum melt viscosity>
The melt viscosity of the resin composition layer of the resin sheet produced in the following Examples and Comparative Examples was measured using a dynamic viscoelasticity measuring device ("Rheosol-G3000" manufactured by UBM). Using 1 g of the resin composition as a sample, using a parallel plate with a diameter of 18 mm, the temperature was raised from a starting temperature of 60 ° C. to 200 ° C. at a temperature increase rate of 5 ° C./min, the measurement temperature interval was 2.5 ° C., the vibration was 1 Hz, The dynamic viscoelastic modulus was measured under the measurement condition of 1 degree of strain, and the minimum melt viscosity (poise) was confirmed.

<Measurement of bleedout amount>
The shape of the end of the insulating layer of evaluation board B was observed according to the following procedure. CCD observation was performed near the end of the support, and the distance (mm) from the end of the support to the end of the bleed-out resin was measured.

<Measurement of undulation>
The shape of the end of the insulating layer of evaluation board B was observed according to the following procedure. Regarding the insulating layer near the end of the support, SEM observation of a cross section of the insulating layer was performed, and the surface of the insulating layer bonded to the support was observed from the top of the insulating layer, that is, from the height of the bottom of the support. The distance (height) was calculated (μm). SEM observation was performed using "S-4800" manufactured by Hitachi High Technologies.

In addition, the following criteria were used to evaluate the amount of bleed out and undulation.
〇: Bleed-out amount is 0 mm and undulation is 2 μm or less △: Bleed-out amount is 0 mm or undulation is 2 μm or less ×: Bleed-out amount exceeds 0 mm and undulation exceeds 2 μm

<Example 1>
(1) Preparation of support A PET film with an alkyd resin release layer (“AL-5” manufactured by Lintec, thickness 38 μm, hereinafter referred to as “release PET film”) was prepared with the TD direction of the PET film being vertical. Fix the edge on one side in the TD direction so that the tension is applied uniformly to the entire PET film, and then apply tension uniformly to the entire PET film on the edge on the other side in the TD direction. A metal plate was placed as a weight so that tension was applied. At that time, the weight of the metal plate was adjusted so that a tension of 20 gf/cm ² was applied. A support was obtained by performing a preheating treatment in which the support was heated under atmospheric pressure at a preheating temperature of 130° C. for a heating time of 30 minutes while applying a tension of 20 gf/cm ² .

(2) Preparation of resin varnish A 30 parts of biphenyl-type epoxy resin (epoxy equivalent: approx. 290 g/eq., “NC3000H” manufactured by Nippon Kayaku Co., Ltd.), naphthalene-type tetrafunctional epoxy resin (epoxy equivalent: 162 g/eq., manufactured by DIC Corporation) "HP-4700") 5 parts, liquid bisphenol A type epoxy resin (epoxy equivalent 180 g/eq., Mitsubishi Chemical Corporation "jER828EL") 15 parts, and phenoxy resin (weight average molecular weight 35000, Mitsubishi Chemical Corporation "YX7553BH30") , 2 parts of a methyl ethyl ketone (MEK) solution containing 30% by mass of nonvolatile components was heated and dissolved in a mixed solvent of 8 parts of MEK and 8 parts of cyclohexanone while stirring. There, 32 parts of a triazine skeleton-containing phenol novolac curing agent (phenolic hydroxyl equivalent: approximately 124 g/eq., "LA-7054" manufactured by DIC Corporation, MEK solution containing 60% by mass of non-volatile components), and a phosphorus curing accelerator (Hokuko Co., Ltd.) were added. "TBP-DA" manufactured by Kagaku Kogyo Co., Ltd., 0.2 part of tetrabutylphosphonium decanoate), spherical silica surface-treated with an aminosilane coupling agent ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.) ("SOC2" manufactured by Admatex Co., Ltd.) , average particle size 0.5 μm) 160 parts, polyvinyl butyral resin solution (weight average molecular weight 27,000, glass transition temperature 105°C, "KS-1" manufactured by Sekisui Chemical Co., Ltd., mass of ethanol and toluene with a nonvolatile content of 15% by mass) Resin varnish A was prepared by mixing 2 parts of a mixed solution with a ratio of 1:1 and uniformly dispersing it with a high-speed rotating mixer. When the total mass of nonvolatile components in resin varnish A was 100% by mass, the content of the inorganic filler (spherical silica) was 69.4% by mass.

(3) Preparation of resin sheet On the release layer of the support prepared in (1) above, the resin varnish A prepared in (2) above is applied with a die coater so that the margins at the ends are 0.5 mm in width in the width direction. Resin varnish A was uniformly applied so that the width of the resin composition layer was 506 mm, the center margin was 1 mm, the width of the resin composition layer was 506 mm, and the margin was 0.5 mm. After coating, it was dried at 80° C. to 120° C. (average 100° C.) for 6 minutes to form a resin composition layer bonded to the support. The thickness of the obtained resin composition layer was 40 μm, and the amount of residual solvent was about 2% by mass. Next, a polypropylene film (thickness: 15 μm) was bonded to the resin composition layer as a protective film and wound up into a roll. The length direction (longitudinal direction) of the obtained rolled resin sheet was slit at the center of the central margin, and the width direction was slit to a width of 336 mm, with a margin of 0.5 mm at both ends and a size of 507 mm. A resin sheet of 336 mm was obtained.

[Preparation of evaluation board]
(1) Preparation of inner layer substrate A glass cloth-based epoxy resin double-sided copper-clad laminate (copper layer thickness 18 μm, substrate thickness 0.8 mm, “R1515A” manufactured by Panasonic Electric Works Co., Ltd.) was prepared as an inner layer substrate. The surface of the copper layer was roughened by immersing both surfaces of the inner layer substrate in a micro-etching agent ("CZ8100" manufactured by MEC Corporation).

(2) Lamination of resin sheets Using a batch vacuum pressure laminator ("MVLP-500" manufactured by Meiki Manufacturing Co., Ltd.), the resin sheets were stacked on both sides of the inner layer substrate so that the resin composition layer was bonded to the inner layer substrate. laminated to. The lamination process was performed by reducing the pressure for 30 seconds to bring the atmospheric pressure to 13 hPa or less, and then press-bonding at 100° C. and a pressure of 0.74 MPa for 30 seconds. Note that the resin sheet was used after the protective film was peeled off.

(3) Thermosetting of the resin composition layer After the resin sheets are laminated, the resin composition layer is thermally cured by heating at 100°C for 30 minutes with the support attached, and then heating at 180°C for 30 minutes. An insulating layer was formed. The thickness of the resulting insulating layer directly above the copper layer was 40 μm. The obtained structure is called evaluation board A.

(4) Formation of second and subsequent insulating layers After peeling off the support from the evaluation board A obtained in (3) above, a resin sheet of the same size as the cured insulating layer was attached to (2) and (2) above. 3) was repeated three times to form four insulating layers. The obtained structure is referred to as evaluation board B.

<Example 2>
In Example 1, the width of the margins at both ends of the resin sheet was changed from 0.5 mm to 1 mm. A resin sheet was produced and laminated in the same manner as in Example 1 except for the above matters.

<Example 3>
In Example 1, the width of the margins at both ends of the resin sheet was changed from 0.5 mm to 2 mm. A resin sheet was produced and laminated in the same manner as in Example 1 except for the above matters.

<Example 4>
In Example 1, the width of the margins at both ends of the resin sheet was changed from 0.5 mm to 4 mm. A resin sheet was produced and laminated in the same manner as in Example 1 except for the above matters.

<Example 5>
In Example 1, resin varnish A was changed to resin varnish B prepared as follows. A resin sheet was produced and laminated in the same manner as in Example 1 except for the above matters.

-Preparation of resin varnish B-
28 parts of liquid bisphenol A type epoxy resin (epoxy equivalent: 180 g/eq., "jER828EL" manufactured by Mitsubishi Chemical Corporation), 28 parts of naphthalene type tetrafunctional epoxy resin (epoxy equivalent: 163 g/eq., "HP-4700" manufactured by DIC Corporation) was heated and dissolved in a mixed solvent of 15 parts of methyl ethyl ketone (MEK) and 15 parts of cyclohexanone with stirring. There, 110 parts of a naphthol curing agent having a novolac structure (phenolic hydroxyl equivalent: 215 g/eq., "SN-485" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., MEK solution with 50% nonvolatile components), and a curing accelerator (Shikoku Kasei Kogyo Co., Ltd.) 70 parts of spherical silica ("SOC2" manufactured by Admatex, average particle size 0.5 μm), polyvinyl butyral resin solution ("KS-1" manufactured by Sekisui Chemical Co., Ltd.), glass transition Resin varnish B was prepared by mixing 35 parts of a 1:1 mixed solution of ethanol and toluene containing 15% non-volatile components at a temperature of 105° C. and uniformly dispersing the mixture using a high-speed rotating mixer. The content of the inorganic filler in resin varnish B was 38% by mass when the nonvolatile components in resin varnish B were 100% by mass.

<Example 6>
In Example 5, the width of the margins at both ends of the resin sheet was changed from 0.5 mm to 1 mm. A resin sheet was produced and laminated in the same manner as in Example 5 except for the above matters.

<Example 7>
In Example 5, the width of the margins at both ends of the resin sheet was changed from 0.5 mm to 2 mm. A resin sheet was produced and laminated in the same manner as in Example 5 except for the above matters.

<Example 8>
In Example 5, the width of the margins at both ends of the resin sheet was changed from 0.5 mm to 4 mm. A resin sheet was produced and laminated in the same manner as in Example 5 except for the above matters.

<Example 9>
In Example 1, the number of laminated layers was changed from 4 to 5. A resin sheet was produced and laminated in the same manner as in Example 1 except for the above matters.

<Example 10>
In Example 9, the width of the margins at both ends of the resin sheet was changed from 0.5 mm to 4 mm. A resin sheet was produced and laminated in the same manner as in Example 9 except for the above matters.

<Example 11>
In Example 5, the number of laminated layers was changed from 4 to 5. A resin sheet was produced and laminated in the same manner as in Example 5 except for the above matters.

<Example 12>
In Example 11, the width of the margins at both ends of the resin sheet was changed from 0.5 mm to 4 mm. A resin sheet was produced and laminated in the same manner as in Example 11 except for the above matters.

<Example 13>
In Example 1, the number of laminated layers was changed from 4 to 6. A resin sheet was produced and laminated in the same manner as in Example 1 except for the above matters.

<Example 14>
In Example 13, the width of the margins at both ends of the resin sheet was changed from 0.5 mm to 4 mm. A resin sheet was produced and laminated in the same manner as in Example 13 except for the above matters.

<Example 15>
In Example 5, the number of laminated layers was changed from 4 to 6. A resin sheet was produced and laminated in the same manner as in Example 5 except for the above matters.

<Example 16>
In Example 15, the width of the margins at both ends of the resin sheet was changed from 0.5 mm to 4 mm. A resin sheet was produced and laminated in the same manner as in Example 15 except for the above matters.

<Comparative example 1>
In Example 1, the width of the margins at both ends of the resin sheet was changed from 0.5 mm to 0 mm. A resin sheet was produced and laminated in the same manner as in Example 1 except for the above matters.

<Comparative example 2>
In Example 5, the width of the margins at both ends of the resin sheet was changed from 0.5 mm to 0 mm. A resin sheet was produced and laminated in the same manner as in Example 5 except for the above matters.

<Comparative example 3>
In Example 9, the width of the margins at both ends of the resin sheet was changed from 0.5 mm to 0 mm. A resin sheet was produced and laminated in the same manner as in Example 9 except for the above matters.

<Comparative example 4>
In Example 11, the width of the margins at both ends of the resin sheet was changed from 0.5 mm to 0 mm. A resin sheet was produced and laminated in the same manner as in Example 11 except for the above matters.

<Comparative example 5>
In Example 13, the width of the margins at both ends of the resin sheet was changed from 0.5 mm to 0 mm. A resin sheet was produced and laminated in the same manner as in Example 13 except for the above matters.

<Comparative example 6>
In Example 15, the width of the margins at both ends of the resin sheet was changed from 0.5 mm to 0 mm. A resin sheet was produced and laminated in the same manner as in Example 15 except for the above matters.

It can be seen that in Examples 1 to 16, the bleed-out amount was 0 mm, and the undulation was 2 μm or less. This shows that the yield of printed wiring boards manufactured by laminating three or more insulating layers in multiple stages is improved. On the other hand, in Comparative Examples 1 to 6, which do not have a margin, the bleedout amount exceeds 0 mm and the undulation exceeds 2 μm, which indicates that the yield was inferior to Examples 1 to 16. .

1 Resin sheet 11 Resin sheet 2 Support body 3 Resin composition layer 4 Margin portions 21, 22, 27, 28 End portions 23, 24, 25, 26 Side 10 Inner layer substrate

Claims (10)

(A) A first resin sheet including a first support and a first resin composition layer provided on the first support, and the first resin composition layer is an inner layer substrate. a step of laminating the inner layer substrate so as to bond with the inner layer substrate;
(B) a step of thermally curing the first resin composition layer to form an insulating layer;
(C) a step of removing the first support; and (D) a second resin comprising a second support and a second resin composition layer provided on the second support. The steps of laminating the sheet on the insulating layer with the second resin composition layer facing the insulating layer side, thermosetting the second resin composition layer, and removing the second support are performed in this order. including,
Step (D) is repeated two or more times,
The first support has first margins in which the first resin composition layer is not provided at two or more ends of the first support,
The second support has second margins in which the second resin composition layer is not provided at two or more ends of the second support ,
A first margin is formed at the end of one side of the first support and at the end of the opposite side, and the widths of these two first margins are approximately the same. can be,
A second margin is formed at the end of one side of the second support and at the end of the opposite side, and the widths of these two second margins are approximately the same. A method of manufacturing printed wiring boards. The method for manufacturing a printed wiring board according to claim 1, wherein step (D) is repeated three or more times. The print according to claim 1 or 2, wherein the first support is rectangular when viewed from the thickness direction, and the first margin is formed at an end of two or more sides of the first support. Method of manufacturing wiring boards. The print according to any one of claims 1 to 3, wherein the first margin is formed at an end of one side of the first support and an end of the opposite side. Method of manufacturing wiring boards. The method for manufacturing a printed wiring board according to any one of claims 1 to 4 , wherein the first margin has a width of 0.1 mm or more and 10 mm or less. The method for manufacturing a printed wiring board according to any one of claims 1 to 5 , wherein the first resin composition layer has a minimum melt viscosity of 10 poise or more and 1,000,000 poise or less. Any one of claims 1 to 6, wherein the second support is rectangular when viewed from the thickness direction, and the second margin is formed at an end of two or more sides of the second support. The method for manufacturing a printed wiring board as described in . The print according to any one of claims 1 to 7 , wherein the second margin is formed at an end of one side of the second support and an end of the opposite side. Method of manufacturing wiring boards. The method for manufacturing a printed wiring board according to any one of claims 1 to 8 , wherein the width of the second margin is 0.1 mm or more and 10 mm or less. The method for manufacturing a printed wiring board according to any one of claims 1 to 9 , wherein the second resin composition layer has a minimum melt viscosity of 10 poise or more and 1,000,000 poise or less.

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