TWI708528B - Resin sheet - Google Patents

Abstract

The solution of the present invention is a resin sheet comprising a support and a photocurable resin composition layer for solder resist bonded to the support, wherein the thickness of the resin composition layer is 5 μm or more and 120 μm or less, and the resin composition The elastic modulus of the cured product of the layer at 23°C is 6GPa or more and 40GPa or less.

Description

Resin sheet

The present invention relates to a resin sheet.

The outermost layer of the printed wiring board is usually provided with a solder resist layer for protection during the mounting step of the semiconductor chip (hereinafter also referred to as "part") in order to prevent the solder from adhering to the parts that do not need to be attached and to prevent corrosion of the circuit board. membrane. The solder resist layer is generally formed by providing a layer of a photocurable resin composition on a circuit board, and exposing and developing the layer (for example, Patent Document 1).

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2009-258613 A

In recent years, as lead-free solders have replaced lead-containing solders, the solder reflow temperature has risen during the mounting process of parts. In recent years, in order to achieve the miniaturization of electronic devices, thinner printed wiring boards have been progressing.

As the thickness of the printed wiring board progresses, the inventors have found that in the mounting step of the parts, the printed wiring board will warp, and there will be problems such as circuit distortion or poor contact of the parts.

The subject of the present invention is to provide a thin printed wiring board that can suppress warpage in the mounting step of parts.

The inventors of the present invention continue to focus on the above-mentioned subject, as a result of continuous dedicated review, and found that by combining two solder resist layers with specific thickness and elastic modulus, the above-mentioned subject can be solved, and the present invention is completed.

That is, the present invention includes the following contents.

[1] A printed wiring board comprising a first and second solder resist layer, wherein the thickness of the first solder resist layer is t ₁ (μm), and the modulus of elasticity (23° C.) after curing is When G ₁ (GPa), the thickness of the second solder resist layer is t ₂ (μm), the modulus of elasticity (23°C) after curing is G ₂ (GPa), and the thickness of the printed wiring board is Z (μm) , Satisfy the following conditions (1)~(3): (1)Z≦250; (2)(t ₁ +t ₂ )/Z≧0.1; and (3)G ₁ ×〔t ₁ /(t ₁ + t ₂ )]+G ₂ ×[t ₂ /(t ₁ +t ₂ )]≧6, and G ₁ is 6 or more.

[2] The printed wiring board as described in [1], wherein the glass transition temperature (Tg) of the first solder resist layer after curing is 150°C or higher.

[3] The printed wiring board as described in [1] or [2], wherein the first solder resist layer is formed by curing a resin composition having an inorganic filler content of 60% by mass or more.

[4] The printed wiring board according to any one of [1] to [3], wherein the condition (2) is 0.1≦(t ₁ +t ₂ )/Z≦0.5.

[5] The printed wiring board according to any one of [1] to [4], wherein G ₂ is 6 or more.

[6] The printed wiring board as described in any one of [1] to [5], wherein the elastic modulus (200°C) of the first solder resist layer after curing is G ₁ '(GPa), and the second resist When the elastic modulus (200°C) of the hardened flux layer is G ₂ '(GPa), the following condition (4) is further satisfied: (4) G ₁ '×〔t ₁ /(t ₁ +t ₂ )〕+ G ₂ '×〔t ₂ /(t ₁ +t ₂ )〕≧0.2.

[7] A semiconductor device comprising the printed wiring board as described in any one of [1] to [6].

[8] A resin sheet group, which is a resin sheet group for a solder resist layer of a printed wiring board, comprising a first support body and a first resin composition layer joined to the first support body. A resin sheet, a second resin sheet formed with a second support and a second resin composition layer joined to the second support, and the thickness of the first resin composition layer is t _1p (μm), after curing The modulus of elasticity (23°C) is G ₁ (GPa), the thickness of the second resin composition layer is t _2p (μm), the modulus of elasticity (23°C) after curing is G ₂ (GPa), and the printed wiring When the thickness of the plate is Z (μm), the following conditions (1')~(3') are satisfied: (1')Z≦250;(2')(t _1p +t _2p )/Z≧0.1; and ( 3') G ₁ ×[t _1p /(t _1p +t _2p )]+G ₂ ×[t _2p /(t _1p +t _2p )]≧6, and G ₁ is 6 or more.

According to the present invention, a thin printed wiring board can be provided, which can suppress warpage in the mounting step of parts.

[The form of implementing the invention] [Printed Wiring Board]

The printed wiring board of the present invention includes first and second solder resist layers, and is characterized in that the thickness of the first solder resist layer is t ₁ (μm), and the modulus of elasticity (23° C.) after curing is G ₁ (GPa ). When the thickness of the second solder resist layer is t ₂ (μm), the modulus of elasticity after curing (23°C) is G ₂ (GPa), and the thickness of the printed wiring board is Z (μm), the following is satisfied Conditions (1)~(3): (1)Z≦250; (2)(t ₁ +t ₂ )/Z≧0.1; and (3)G ₁ ×〔t ₁ /(t ₁ +t ₂ )〕 +G ₂ ×[t ₂ /(t ₁ +t ₂ )]≧6, and G ₁ is 6 or more.

The printed wiring board of the present invention comprising a combination of the first and second solder resist layers with specific thickness and elastic modulus can suppress warpage and circuits in the mounting process of parts using high solder reflow temperature The occurrence of problems such as distortion or poor contact of parts.

-Condition(1)-

Condition (1) relates to the thickness Z (μm) of the printed wiring board of the present invention. The thickness Z of the printed wiring board means the overall thickness of the printed wiring board including the circuit board and the first and second solder resist layers provided on both sides of the circuit board. The thickness (Z) of the printed wiring board of the present invention is 250 μm or less, preferably 240 μm or less, more preferably 230 μm or less, still more preferably 220 μm or less, and still more preferably 210 μm or less from the viewpoint of thinning. Particularly preferably, it is 200 μm or less, 190 μm or less, 180 μm or less, 170 μm or less, 160 μm or less, or 150 μm or less. The printed wiring board of the present invention can suppress warpage in the mounting step even when the thickness is so thin. The lower limit of the thickness (Z) is not particularly limited, and it is usually 20 μm or more, or 30 μm or more.

-Condition(2)-

Condition (2) relates to the thickness t ₁ (μm) and t ₂ (μm) of the first and second solder resist layers contained in the printed wiring board of the present invention. Here, the thicknesses t ₁ (μm) and t ₂ (μm) of the first and second solder resist layers are the thicknesses from the base surface of the circuit board (the part of the surface of the circuit board that has no surface circuit). From the viewpoint of suppressing the warpage of the printed wiring board in the mounting step, the ratio of the thickness of the first and second solder resist layers and (t ₁ +t ₂ ) to the thickness Z of the printed wiring board is (t ₁ +t ₂ )/Z ratio is 0.1 or more, although it also depends on the value on the right side of condition (3), it is preferably 0.15 or more, more preferably 0.2 or more, 0.22 or more, 0.24 or more, 0.26 or more, 0.28 or more or 0.3 or more. The upper limit of the (t ₁ +t ₂ )/Z ratio is preferably 0.5 or less, more preferably 0.45 or less, still more preferably 0.4 or less, from the viewpoint of obtaining a printed wiring board having a desired wiring density Below, 0.38 or less, 0.37 or less, 0.36 or less, 0.36 or less or 0.34 or less.

The thickness t _{1 of the} first solder resist layer is not particularly limited as long as the above-mentioned specific (t ₁ +t ₂ )/Z ratio is satisfied, and it is preferably 5 μm or more, more preferably 10 μm or more, and still more preferably Above 15μm, above 20μm or above 25μm. The upper limit of the thickness t ₁ is not particularly limited. When the above-mentioned specific (t ₁ +t ₂ )/Z ratio is satisfied, it is not particularly limited. It is preferably 120 μm or less, more preferably 100 μm or less, and still more preferably 80 μm. Below, 70 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, or 30 μm or less.

The thickness t _{2 of} the second solder resist layer is not particularly limited as long as it satisfies the above-mentioned specific (t ₁ +t ₂ )/Z ratio. The thickness t _{1 of the} first solder resist layer and the printed wiring board The thickness Z can be determined. The upper limit of the thickness t ₂ of the second solder resist layer is usually 120 μm or less or 100 μm or less, and the lower limit of the thickness t ₂ is usually 5 μm or more or 10 μm or more.

-Condition (3)-

The condition (3) relates to the elastic modulus (23°C) after curing of the first and second solder resist layers contained in the printed wiring board of the present invention. The first and second solder resist layers can be formed by curing the resin composition as described later. The elastic modulus after curing (23°C) refers to the elastic modulus of the solder resist layer at 23°C after the resin composition is cured. When the elastic modulus (23℃) of the first and second solder resist layers after hardening is G ₁ (GPa) and G ₂ (GPa) respectively, the formula: G ₁ ×〔t ₁ /(t ₁ +t ₂ ) ]+G ₂ ×[t ₂ /(t ₁ +t ₂ )] (hereinafter also referred to as the "average value of G ₁ and G ₂ thickness increase") to suppress the warpage of the printed wiring board in the mounting step From the standpoint of this, it is 6 or more, preferably 6.2 or more, more preferably 6.4 or more, still more preferably 6.6 or more, and still more preferably 6.8 or more. If the average thickness of G ₁ and G ₂ is 6.8 or more, and if the thickness Z of the printed wiring board is 200 μm or less, even when it is thin, the warpage of the printed wiring board in the mounting step can be suppressed. The thickness of G ₁ and G ₂ is increased by the average value. Even if the thickness Z of the printed wiring board is reduced and the (t ₁ +t ₂ )/Z ratio is lower, it is possible to suppress the printed wiring board in the mounting step. From the point of view of warpage, 7 or more, 7.5 or more, 8 or more, 8.5 or more, 9 or more, 9.5 or more, 10 or more, 10.5 or more, 11 or more, 11.5 or more, 12 or more, 12.5 or more or 13 or more are particularly preferred . The upper limit of the average value of the thickness increase of G ₁ and G ₂ is not particularly limited, and it can usually be 40 or less, 30 or less. The modulus of elasticity (23°C) of the first and second solder resist layers after hardening can be measured at 23°C by the tensile weight method using a tensile testing machine. As for the tensile tester, for example, "RTC-1250A" manufactured by ORIENTEC can be mentioned.

The elastic modulus (23°C) of the first solder resist layer after hardening, that is, G ₁ (GPa) is 6 or more. The value of G ₁ is 6 or more, and the average thickness of G ₁ and G ₂ is within the above-mentioned specific range, and is not particularly limited. From the viewpoint that the warpage of the printed wiring board can be sufficiently suppressed in the mounting step, it is preferable 6.2 or more, more preferably 6.4 or more, still more preferably 6.6 or more, still more preferably 6.8 or more, particularly preferably 7 or more, 7.5 or more, 8 or more, 8.5 or more, 9 or more, 9.5 or more, 10 or more, 10.5 Above, above 11, above 11.5, above 12, above 12.5 or above 13. The upper limit of G ₁ is not particularly limited, but it can usually be 40 or less, 30 or less.

The modulus of elasticity (23° C.) of the second solder resist layer after hardening, that is, G ₂ (GPa), is not particularly limited if the average thickness of G ₁ and G ₂ is within the above-mentioned specific range. For example, as long as the value G ₂ is G ₁ and G ₂ the thickness of the average increase in the specific range may be determined to be in the range of 1 to 30. From the point of view that it is easy to suppress the warpage of the printed wiring board in the mounting step even when the thickness Z of the printed wiring board is reduced and the (t ₁ +t ₂ )/Z ratio is lowered, the value of G ₂ The series of 6 or more is particularly good.

From the viewpoint of further suppressing the warpage of the printed wiring board in the mounting step, the elastic modulus (200°C) of the first and second solder resist layers after curing is G ₁ '(GPa) and G ₂ '(GPa), the following condition (4) is satisfied: (4) G ₁ '×〔t ₁ /(t ₁ +t ₂ )〕+G ₂ '×〔t ₂ /(t ₁ +t ₂ )〕 ≧0.2 is better.

G ₁ '×〔t ₁ /(t ₁ +t ₂ )〕+G ₂ '×〔t ₂ /(t ₁ +t ₂ )〕 (hereinafter also referred to as the thickness of "G ₁ 'and G ₂ ' Aggravated average") is better if it is 0.22 or more, and better if it is 0.24 or more. If the thicknesses of G ₁ ′ and G ₂ ′ are weighted to an average value of 0.24 or more, even when the thickness Z of the printed wiring board is made thinner to 200 μm or less, the warpage of the printed wiring board in the mounting step can be suppressed. The average thickness of G ₁ 'and G ₂ ' is increased to suppress printed wiring in the mounting step even when the thickness Z of the printed wiring board is reduced and the (t ₁ +t ₂ )/Z ratio is lower From the viewpoint of the warpage of the board, it is particularly preferred to be 0.3 or more, 0.4 or more, 0.5 or more, 0.6 or more, 0.7 or more, 0.8 or more, 0.9 or more, 1.0 or more, 1.1 or more, 1.2 or more, 1.3 or more or 1.4 or more. The upper limit of the average thickness of G ₁ ′ and G ₂ ′ is not particularly limited, and it can usually be 15 or less, 10 or less. In addition, the so-called modulus of elasticity after curing (200°C) means the modulus of elasticity of the solder resist layer at 200°C after the resin composition is cured, and can be set at 200°C by a tensile tester using a tensile tester. Determination.

The modulus of elasticity (200°C) of the first solder resist layer after hardening is G ₁ '(GPa). From the viewpoint of sufficiently suppressing the warpage of the printed wiring board in the mounting step, it is preferably 0.2 or more , 0.22 or more is more preferable, 0.24 or more is more preferably, 0.3 or more, 0.4 or more, 0.5 or more, 0.6 or more, 0.7 or more, 0.8 or more, 0.9 or more, 1.0 or more, 1.1 or more, 1.2 or more, 1.3 or more or 1.4 or more Especially good. The upper limit of G ₁ ′ is not particularly limited, and it can usually be 15 or less, 10 or less.

The elastic modulus (200°C) of the second solder resist layer after hardening, namely G ₂ '(GPa), in the relationship with G ₁ ', the average value of the thickness increase of G ₁ 'and G ₂ ' is such that The value of a specific range is better. For example, the 'value, as long as the G _1' G ₂ and a thickness G ₂ 'is the average increase in the specific range, preferably in the line to the range of 0.1 to 10. From the viewpoint of suppressing the warpage of the printed wiring board in the mounting step even when the thickness Z of the printed wiring board is reduced and the (t ₁ +t ₂ )/Z ratio is lower, the value of G ₂ ' The one with 0.2 or more is particularly good.

In the printed wiring board of the present invention that satisfies the above-mentioned conditions (1), (2), and (3), warpage can be suppressed even in the mounting step using a high solder reflow temperature. In one embodiment, the printed wiring board of the present invention can suppress the warpage of the printed wiring board to 50 μm or less in the mounting step using a high solder reflow temperature with a peak temperature of 260°C. In the present invention, the warpage of the printed wiring board is the difference between the maximum height and the minimum height of the displacement data when observing the warping behavior of the 25mm corner portion of the center of the printed wiring board with a shadow moire device value. During the measurement, the reflow temperature profile (curve for lead-free components; peak temperature) described in IPC/JEDEC J-STD-020C ("Moisture/Reflow Sensitivity Classification For Nonhermetic Solid State Surface Mount Devices", July 2004) was reproduced 260°C, 5 minutes for the temperature rise from 25°C to the peak temperature) After the reflow device is passed through the printed wiring board once, the printed wiring is heated according to the reflow temperature profile according to the above IPC/JEDEC J-STD-020C The displacement data is obtained by the grid lines provided on one side of the board and the other side of the printed wiring board. In addition, for the reflow device, for example, "HAS-6116" manufactured by ANTUM, Japan, and for the shadow moiré device, for example, "TherMoire AXP" manufactured by Akrometrix. By setting the value on the right side of the condition (3) to the above-mentioned preferable value, even if the thickness Z of the printed wiring board is reduced and the (t ₁ +t ₂ )/Z ratio is lower, the mounting can be achieved In the step, the warpage of the printed wiring board is suppressed to 48 μm or less, 46 μm or less, 44 μm or less, 42 μm or less, or 40 μm or less.

[Resin sheet set for solder resist layer of printed wiring board]

The printed wiring board of the present invention can be manufactured by providing the first and second solder resist layers having specific thickness and elastic modulus on both sides of a circuit board.

Hereinafter, a group of resin sheets ("resin sheet group") used when manufacturing the printed wiring board of the present invention will be described.

The resin sheet set for the solder resist layer of the printed wiring board of the present invention is characterized by comprising a first resin sheet formed of a first support and a first resin composition layer bonded to the first support, and a 2 The support and the second resin sheet formed by the second resin composition layer joined to the second support, and the thickness of the first resin composition layer is t _1p (μm), the elastic modulus after curing (23 °C) is G ₁ (GPa), the thickness of the second resin composition layer is t _2p (μm), the modulus of elasticity after curing (23 °C) is G ₂ (GPa), and the thickness of the printed wiring board is Z (μm), meet the following conditions (1')~(3'): (1')Z≦250;(2')(t _1p +t _2p )/Z≧0.1; and (3')G ₁ ×[t _1p /(t _1p +t _2p )]+G ₂ ×[t _2p /(t _1p +t _2p )]≧6, and G ₁ is 6 or more.

By using this group of resin sheets to form the first and second solder resist layers, the printed wiring board of the present invention that satisfies the conditions (1), (2), and (3) can be easily manufactured.

The condition (1') corresponds to the above condition (1). The preferable range of Z is as described in condition (1).

The condition (2') corresponds to the above condition (2). When a resin composition layer is laminated on a circuit board and a solder resist layer is formed, the presence of a circuit on the surface of the circuit board is the cause. Generally, the thickness of the resulting solder resist layer is thicker than the thickness of the resin composition layer. Therefore, by satisfying the condition (2'), it is not affected by the thickness of the surface circuit of the circuit board or the density of the surface circuit, and the condition (2) is easily satisfied. In condition (2'), when determining the preferable range of (t _1p + t _2p )/Z ratio, “t ₁ ”and “t ₂ ” in condition (2) can be interpreted as “t _1p ”and "T _2p " is applicable. Similarly, when determining the preferred ranges of t _1p and t _2p , in the description of the preferred ranges of t ₁ and t ₂ in the additional description of the above condition (2), "t ₁ "and "t ₂ " can be respectively Change to read "t _1p " and "t _2p " to apply. In addition, when deciding t _1p and t _2p , it is better to decide these to be the same or thicker as the surface circuit thickness of the circuit board.

The condition (3') corresponds to the above condition (3). When the modulus of elasticity (23°C) of the solder resist layer after curing indicates the modulus of elasticity (23°C) of the resin composition used to form the solder resist layer, as mentioned above, the preferred ranges of G ₁ and G ₂ are: It is as described in condition (3). In addition, the preferable range of the value on the right side of the condition (3') is as described in the condition (3).

From the viewpoint that the warpage of the printed wiring board can be further suppressed in the mounting step, the elastic modulus (200°C) of the first and second resin composition layers after curing are respectively G ₁ '(GPa) and G ₂ ' (GPa), meet the following conditions (4'):

(4')G ₁ '×〔t _1p /(t _1p +t _2p )〕+G ₂ '×〔t _2p /(t _1p +t _2p )〕≧0.2. The preferable range of the value on the right side of the condition (4') is as described in the condition (4), and the preferable range of G ₁ ′ and G ₂ ′ is as described in the condition (4).

<Resin composition>

The resin composition used in the first and second resin composition layers can be a thermosetting resin composition if it can exhibit the above-mentioned specific elastic modulus while having sufficient chemical resistance and insulation after curing. The material may be a photocurable resin composition. For example, as for the thermosetting resin composition, a resin composition containing a thermosetting resin and a curing agent can be mentioned. Regarding the thermosetting resin, conventionally known thermosetting resins used when forming the solder resist layer of a printed wiring board can be used, and among them, epoxy resins are more preferable. Therefore, in one embodiment, the thermosetting resin composition system used in the first and second resin composition layers contains (a) an epoxy resin and (b) a curing agent. Furthermore, a preferable photocurable resin composition system can be formed by adding a photocurable resin to the thermosetting resin composition. As for the photocurable resin, the conventionally known photocurable resin used when forming the solder resist layer of the printed wiring board can be used. From the viewpoint of easy exposure/development (photolithography) to form openings, Light-curing alkali-soluble resin is preferred. Therefore, in one embodiment, the photocurable resin composition used in the first and second resin composition layers includes (a) epoxy resin, (b) curing agent, and (c) photocurable alkali-soluble resin . The photocurable resin composition further contains one or more selected from the group consisting of (d) photopolymerization initiator, (e) photosensitizer, and (f) diluent. In addition, in the present invention, a resin composition containing a photocurable resin and capable of forming openings by photolithography is also called a "photocuring resin composition" even when it has thermosetting properties. The resin composition that can be used in the first and second resin composition layers, regardless of the classification of the thermosetting resin composition and the photocuring resin composition, may further include (g) inorganic fillers and (h) thermal Additives such as plastic resin, (i) hardening accelerator, (j) flame retardant, and (k) organic filler.

The following is for epoxy resins, hardeners, light-curing alkali-soluble resins, photopolymerization initiators, photosensitizers, and diluents that can be used as materials for the resin composition in the first and second resin composition layers And additives are described.

-(a) Epoxy resin-

Regarding epoxy resins, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, dicyclopentadiene type epoxy resin, Ginseng phenol type epoxy resin, naphthol novolac type epoxy resin, phenol novolac type epoxy resin, tert-butyl-benzenediol type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, Anthracene type epoxy resin, epoxy propyl amine type epoxy resin, glycidyl ester type epoxy resin, cresol novolak type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin, Epoxy resin with butadiene structure, alicyclic epoxy resin, heterocyclic epoxy resin, epoxy resin containing spiro ring, cyclohexane dimethanol type epoxy resin, naphthyl ether type epoxy resin and three Hydroxymethyl type epoxy resin, etc. The epoxy resin can be used individually by 1 type or in combination of 2 or more types.

The epoxy resin is preferably an epoxy resin containing two or more epoxy groups in one molecule. When the non-volatile content of the epoxy resin is 100% by mass, at least 50% by mass or more is preferably an epoxy resin having two or more epoxy groups per molecule. Among them, it further includes an epoxy resin that has two or more epoxy groups in one molecule and is liquid at a temperature of 20°C (hereinafter referred to as "liquid epoxy resin") and three or more epoxy groups in one molecule. In addition, a solid epoxy resin (hereinafter referred to as "solid epoxy resin") at a temperature of 20°C is preferred. Regarding epoxy resin, a combination of liquid epoxy resin and solid epoxy resin can be used to obtain a resin composition with excellent flexibility. In addition, the fracture strength of the solder resist layer formed by curing the resin composition is also improved. In particular, when the resin composition is a thermosetting resin composition, it is preferable to use a combination of a liquid epoxy resin and a solid epoxy resin. When the resin composition is a photocurable resin composition, it is preferable to use a solid epoxy resin as the epoxy resin.

For liquid epoxy resins, bisphenol A epoxy resins, bisphenol F epoxy resins, phenol novolac epoxy resins, and naphthalene epoxy resins are preferred. Bisphenol A epoxy resins, Bisphenol F type epoxy resin and naphthalene type epoxy resin are more preferable. Specific examples of liquid epoxy resins include "HP4032", "HP4032D", "HP4032SS" (naphthalene type epoxy resin) manufactured by DIC Corporation, and "jER828EL" manufactured by Mitsubishi Chemical Corporation (double Phenolic A type epoxy resin), "jER807" (bisphenol F type epoxy resin), "jER152" (phenol novolak type epoxy resin), "ZX1059" (bisphenol resin) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. A-type epoxy resin and bisphenol F-type epoxy resin), "EX-721" (glycidyl ester epoxy resin) manufactured by Nagase ChemteX. These can be used individually by 1 type or in combination of 2 or more types.

For solid epoxy resin, naphthalene type tetrafunctional epoxy resin, cresol novolac type epoxy resin, dicyclopentadiene type epoxy resin, ginseng phenol type epoxy resin, naphthol novolak type epoxy resin Resin, biphenyl type epoxy resin, or naphthalene ether type epoxy resin is preferable, naphthalene type tetrafunctional epoxy resin, biphenyl type epoxy resin, or naphthalene ether type epoxy resin is more preferable, naphthalene type tetrafunctional epoxy resin Resin and biphenyl type epoxy resin are better. Specific examples of solid epoxy resins include "HP-4700", "HP-4710" (naphthalene type tetrafunctional epoxy resin), and "N-690" (cresol novolak) manufactured by DIC Corporation. Type epoxy resin), "N-695" (cresol novolak type epoxy resin), "HP-7200" (dicyclopentadiene type epoxy resin), "EXA7311", "EXA7311-G3", " EXA7311-G4”, “EXA7311-G4S”, “HP6000” (naphthyl ether type epoxy resin), “EPPN-502H” (ginseng phenol epoxy resin) manufactured by Nippon Kayaku Co., Ltd., “NC7000L” (naphthol Novolac epoxy resin), "NC3000H", "NC3000", "NC3000L", "NC3100" (biphenyl type epoxy resin), "ESN475" (naphthol novolac type) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. Epoxy resin), "ESN485V" (naphthol novolak type epoxy resin), "YX4000H", "YL6121" (biphenyl type epoxy resin) manufactured by Mitsubishi Chemical Corporation, "YX4000HK" (bixylenol) Type epoxy resin), "PG-100" and "CG-500" manufactured by Osaka Gas Chemical Co., Ltd., and "YL7800" (茀 type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd.

Regarding epoxy resins, when liquid epoxy resins and solid epoxy resins are used together, the amount ratio (liquid epoxy resin: solid epoxy resin) is based on a mass ratio of 1:0.1~1 : The range of 4 is better. By setting the ratio of the liquid epoxy resin to the solid epoxy resin within this range, the following effects can be obtained: i) when used in the form of a resin sheet, it has moderate adhesiveness, and ii) when the resin sheet is used When used in the form, sufficient flexibility and improved drawability can be obtained, and iii) a solder resist layer with sufficient breaking strength can be obtained. From the viewpoint of the effects of i) to iii) above, the ratio of the amount of liquid epoxy resin to solid epoxy resin (liquid epoxy resin: solid epoxy resin) is calculated as a mass ratio, which is 1: The range of 0.3~1:3.5 is better, the range of 1:0.6~1:3 is even better, and the range of 1:0.8~1:2.5 is particularly preferred.

The content of the epoxy resin in the resin composition is preferably 3% by mass or more, more preferably 5% by mass or more, and still more preferably 7% by mass or more or 9% by mass or more. The upper limit of the content of the epoxy resin is not particularly limited, but is preferably 50% by mass or less, more preferably 45% by mass or less, and still more preferably 40% by mass or less or 35% by mass or less.

In addition, in the present invention, the content of each component constituting the resin composition is a value when the total of the non-volatile components in the resin composition is 100% by mass.

The epoxy equivalent of the epoxy resin is preferably 50 to 3000, more preferably 80 to 2000, and still more preferably 110 to 1000. In this range, the crosslink density of the cured product is sufficient, and it has a solder resist layer with excellent heat resistance. In addition, epoxy equivalent can be measured in accordance with JIS K7236, which is the mass of a resin containing 1 equivalent of epoxy group.

The weight average molecular weight of the epoxy resin is preferably 100 to 5000, more preferably 250 to 3000, and still more preferably 400 to 1500. Here, the weight average molecular weight of the epoxy resin is the weight average molecular weight in terms of polystyrene measured by the gel permeation chromatography (GPC) method.

-(b) Hardener-

The curing agent is not particularly limited if it has the function of curing epoxy resin. For example, phenol curing agent, naphthol curing agent, active ester curing agent, benzoxazine curing agent, and cyanate ester The ester hardener. The curing agent can be used alone or in combination of two or more.

In terms of phenol hardeners and naphthol hardeners, from the viewpoint of obtaining a solder resist layer with excellent heat resistance and water resistance, they are based on a phenol hardener with a novolak structure or a naphthol with a novolak structure. The hardener is better. In addition, from the viewpoint of obtaining a solder resist layer having excellent adhesion to the circuit board, a nitrogen-containing phenol-based hardener is preferable, and a phenol-based hardener containing a triazine skeleton is more preferable. Among them, from the viewpoint of obtaining a solder resist layer that satisfies high heat resistance, water resistance, and adhesion to the circuit board, a phenol novolak resin containing a triazine skeleton is more preferable.

Specific examples of phenol hardeners and naphthol hardeners include "MEH-7700", "MEH-7810", and "MEH-7851" manufactured by Meiwa Chemical Co., Ltd., and Nippon Kayaku Co., Ltd. "NHN", "CBN", "GPH", "SN170", "SN180", "SN190", "SN475", "SN485", "SN495", "SN375", "SN395" of Toto Kasei Co., Ltd. ", DIC (share) system "LA7052", "LA7054", "LA3018", etc.

From the viewpoint of obtaining a solder resist layer excellent in heat resistance, an active ester-based hardener is also preferable. There are no particular restrictions on the active ester curing agent. Generally, phenol esters, thiophene esters, N-hydroxylamine esters, heterocyclic hydroxy compound esters, etc. are used to have two or more highly reactive molecules per molecule. Ester-based compounds are preferred. The active ester hardener is preferably obtained by the condensation reaction of a carboxylic acid compound and/or a thiocarboxylic acid compound and a hydroxyl compound and/or a thiol compound. In particular, from the viewpoint of improving heat resistance, an active ester curing agent derived from a carboxylic acid compound and a hydroxy compound is preferred, and an active ester curing agent derived from a carboxylic acid compound, a phenol compound and/or a naphthol compound is preferred Better. The carboxylic acid compound includes, for example, benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid. As for the phenol compound or naphthol compound, for example, hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalein, methylated bisphenol A, methylated bisphenol F, methyl Bisphenol S, phenol, o-cresol, m-cresol, p-cresol, hydroquinone, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxyl Naphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, 1,3,5-benzenetriol, 1,2,4-benzenetriol , Dicyclopentadiene type diphenol compound, phenol novolac, etc. Here, the "dicyclopentadiene type diphenol compound" refers to a diphenol compound obtained by condensing two molecules of phenol in one molecule of dicyclopentadiene.

Specifically, it is an active ester compound containing a dicyclopentadiene type diphenol structure, an active ester compound containing a naphthalene structure, an active ester compound containing an acetyl compound of a phenol novolak, and a benzyl containing a phenol novolak. Active ester compounds of acyl compounds are preferred, and among them, active ester compounds containing naphthalene structure and active ester compounds containing dicyclopentadiene type diphenol structure are more preferred. The so-called "dicyclopentadiene-type diphenol structure" refers to a bivalent structural unit formed by phenylene-dicyclopentene-phenylene.

Commercially available active ester hardeners, and active ester compounds containing dicyclopentadiene-type diphenol structure include "EXB9451", "EXB9460", "EXB9460S", and "HPC-8000-65T" ( For active ester compounds containing naphthalene structure, "EXB9416-70BK" (manufactured by DIC), for active ester compounds containing phenol novolac-based acetone compounds, for example, "DC808" (manufactured by Mitsubishi Chemical Co., Ltd.), active ester compounds containing phenol novolac-based benzyl compounds, include "YLH1026" (manufactured by Mitsubishi Chemical Co., Ltd.) and the like.

Specific examples of the benzoxazine-based curing agent include "HFB2006M" manufactured by Showa High Polymer Co., Ltd., and "P-d" and "F-a" manufactured by Shikoku Chemical Industry Co., Ltd..

Regarding the cyanate ester-based curing agent, for example, bisphenol A dicyanate, polyphenol cyanate, oligo(3-methylene-1,5-phenylene cyanate), 4,4 '-Methylene bis(2,6-dimethylphenyl cyanate), 4,4'-ethylene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2 -Bis (4-cyanate ester) phenyl propane, 1,1-bis (4-cyanate ester phenyl methane), bis (4-cyanate ester-3,5-dimethylphenyl) methane, 1 , 3-bis(4-cyanate phenyl-1-(methyl ethylene))benzene, bis(4-cyanate phenyl)sulfide, and bis(4-cyanate phenyl)ether Such bifunctional cyanate ester resins, polyfunctional cyanate ester resins derived from phenol novolac and cresol novolac, etc., prepolymers in which a part of these cyanate ester resins are triazineized, etc. Specific examples of cyanate ester curing agents include "PT30" and "PT60" manufactured by Lonza Japan (both are phenol novolak type polyfunctional cyanate ester resins), "BA230" (bisphenol A two Part or all of the cyanate ester is triazineized and becomes a three-weight prepolymer).

The ratio of the amount of epoxy resin and hardener is calculated by the ratio of [total number of epoxy groups of epoxy resin]: [total number of reactive groups of hardener], preferably 1:0.2~1:2 The range, 1:0.3~1:1.5 is better, and 1:0.4~1:1.2 is even better. Here, the so-called reactive groups of the curing agent are active hydroxyl groups, active ester groups, etc., which vary depending on the type of curing agent. In addition, the so-called total number of epoxy groups of epoxy resins means that the value obtained by dividing the solid content mass of each epoxy resin by the epoxy equivalent is the total value of all epoxy resins. The so-called reactive group of the hardener The total count refers to the total value obtained by dividing the solid content mass of each hardener by the equivalent of the reactive group to the sum of all hardeners. By setting the ratio of the epoxy resin to the hardener in this range, the heat resistance of the resulting solder resist layer will be more improved.

-(c) Light-curing alkali-soluble resin-

As for the photocurable alkali-soluble resin, if it is a photocurable resin containing an alkali-soluble group (for example, carboxyl group, phenolic hydroxyl group, etc.), it is not particularly limited, and it can also be used when forming a solder resist layer of a printed wiring board. The conventionally known photocurable alkali-soluble resin. Among them, light-curable alkali-soluble resins are more preferably resins containing alkali-soluble groups and radically polymerizable unsaturated groups, resins containing carboxyl groups and radically polymerizable unsaturated groups, phenolic hydroxyl groups and Free radical polymerizable unsaturated resins are better. The photocurable alkali-soluble resin may be used alone or in combination of two or more.

Regarding the resin containing a carboxyl group and a radically polymerizable unsaturated group, for example, an epoxy resin and an unsaturated carboxylic acid are reacted, and then an acid anhydride is reacted to form an acidic cord type unsaturated epoxy ester resin.

Regarding the epoxy resin, it is sufficient to use the same as the component (a). From the viewpoint of obtaining good developability and insulation reliability, bisphenol F epoxy resin and bisphenol A epoxy resin Resin and cresol novolac type epoxy resin are better, and bisphenol F type epoxy resin and cresol novolac type epoxy resin are more preferable. An epoxy resin may be used individually by 1 type, and may use 2 or more types together.

The unsaturated carboxylic acid includes, for example, acrylic acid, methacrylic acid, cinnamic acid, crotonic acid, etc. From the viewpoint of obtaining good photocuring properties, acrylic acid and methacrylic acid are preferred. An unsaturated carboxylic acid may be used individually by 1 type, and may use 2 or more types together.

For carboxylic anhydrides, for example, anhydrous maleic acid, anhydrous succinic acid, anhydrous itaconic acid, anhydrous phthalic acid, anhydrous tetrahydrophthalic acid, anhydrous hexahydrophthalic acid, anhydrous trimellitic acid, anhydrous pyromellitic acid Formic acid, benzophenone tetracarboxylic acid anhydride, etc., from the viewpoint of obtaining good developability and insulation reliability, anhydrous succinic acid and anhydrous tetrahydrophthalic acid are preferred. An acid anhydride may be used individually by 1 type, and may use 2 or more types together.

Acidic cord type unsaturated epoxy ester resin, in the presence of a catalyst, is formed by reacting unsaturated carboxylic acid and epoxy resin to form an unsaturated epoxy ester resin, and the unsaturated epoxy ester resin and Derived from acid anhydride reaction. The reaction system is well-known, and the reaction conditions such as the reaction temperature, the reaction time, the type or the amount of the catalyst used, etc. may be appropriately determined by the industry in the field.

A commercially available product can also be used for the acid-cable type unsaturated epoxy ester resin. Commercial products include "ZFR-1533H" (a reaction product of bisphenol F epoxy resin, acrylic acid, and anhydrous tetrahydrophthalic acid) manufactured by Nippon Kayaku Co., Ltd., and "ZAR-2000" (double (Reaction product of phenol A epoxy resin, acrylic acid, and anhydrous succinic acid), Showa Denko Corporation "PR-3000" (reaction product of cresol novolac epoxy resin, acrylic acid, and carboxylic anhydride), etc.

The resin containing a phenolic hydroxyl group and a radical polymerizable unsaturated group can be synthesized by reacting a resin containing a phenolic hydroxyl group with a compound containing a radical polymerizable unsaturated group and an isocyanate group, for example.

Examples of phenolic hydroxyl-containing resins include phenol novolak resin, cresol novolak resin, bisphenol A novolak resin, and naphthol novolak resin, from the viewpoint of obtaining good developability and insulation reliability. Look, phenol novolac resin and cresol novolac resin are better. The phenolic hydroxyl group-containing resin may be used alone or in combination of two or more kinds.

Regarding the compound containing a radically polymerizable unsaturated group and an isocyanate group, for example, (meth)acrylic acid isocyanate, isocyanate ethyl (meth)acrylate; and a polyisocyanate compound having an isocyanate group reactable The (meth)acrylate compound of a functional group (for example, a hydroxyl group) is partially added to a reaction product obtained by the addition reaction, etc. Here, the polyisocyanate compound includes, for example, 3-isocyanate-3,5,5-trimethylcyclohexyl isocyanate, trichloroethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, methylene Examples of (meth)acrylate compounds having functional groups that can react with isocyanate groups, such as biphenyl isocyanate, polymethylene polyphenyl polyisocyanate, etc., include pentaerythritol tri(meth)acrylate, 2- Hydroxyethyl (meth)acrylate, N-methylol acrylamide, glycerol di(meth)acrylate, dipentaerythritol penta(meth)acrylate, etc.

A resin containing a phenolic hydroxyl group and a radically polymerizable unsaturated group can be obtained by reacting a resin containing a phenolic hydroxyl group with a compound containing a radically polymerizable unsaturated group and an isocyanate group in the presence of a catalyst. The reaction system is well-known, and the reaction conditions such as the reaction temperature, the reaction time, the type or the amount of the catalyst used, etc. may be appropriately determined by the industry in the field.

The polystyrene-converted number average molecular weight (Mn) of the photo-curable alkali-soluble resin is preferably 500 to 1,000,000, more preferably 1,000 to 50,000, and still more preferably, from the viewpoint of obtaining good resolution 1500~35000. The Mn of the photocurable alkali-soluble resin can be measured by, for example, a colloidal permeation chromatography (GPC) method. (GPC) method (polystyrene conversion) can be measured. For Mn, for example, LC-9A/RID-6A manufactured by Shimadzu Corporation is used as the measuring device, Shodex K-800P/K-804L/K-804L manufactured by Showa Denko Corporation is used for the column, and the mobile phase is chloroform, etc. , Measure with the column temperature of 40°C, and use the standard polystyrene calibration curve to calculate.

The solid acid value of the light-curing alkali-soluble resin is preferably 100 mgKOH/g or less, more preferably 90 mgKOH/g or less, from the viewpoint of obtaining a solder resist layer exhibiting good insulation reliability. Less than 80mgKOH/g or less than 70mgKOH/g. As long as sufficient developability can be obtained, the solid content acid value is preferably lower. From this point of view, the photocurable alkali-soluble resin has a phenolic hydroxyl group and a non-radical polymerizable resin. Saturated resins are particularly good.

The content of the photocurable alkali-soluble resin in the resin composition is preferably 10% by mass or more, more preferably 15% by mass or more, and still more preferably 20% by mass or more from the viewpoint of obtaining good developability. . The upper limit of the content of the photocurable alkali-soluble resin is preferably 60% by mass or less, more preferably 50% by mass or less, and still more preferably 40% by mass or less from the viewpoint of obtaining a solder resist layer excellent in heat resistance.

-(d) Photopolymerization initiator-

The photopolymerization initiator is not particularly limited, and examples include 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-1-butanone, 2-(dimethylamino) Amino)-2-[(4-methylphenyl)methyl]-[4-(4-morpholinyl)phenyl]-1-butanone, 2-methyl-[4-(methyl Thio)phenyl)-morpholin-1-acetone, benzophenone, methylbenzophenone, o-benzyl benzoic acid, benzyl ethyl ether, 2,2-di Ethoxyacetophenone, 2,4-diethylthioxanthone, bis(2,4,6-trimethylbenzyl)-phenylphosphine oxide, ethyl-(2 ,4,6-Trimethylbenzyl)phenylphosphonate, 4,4'-bis(diethylamino)benzophenone, 1-hydroxy-cyclohexyl-phenyl ketone, 2, 2-Dimethoxy-1,2-diphenylethane-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1- Alkylbenzene-based photopolymerization initiators such as propane-1-one; bis(2,4,6-trimethylbenzyl)-phenylphosphine oxide and other photopolymerization of phosphine oxides Starter; 1,2-octanedione, 1-[4-(phenylthio)-,2-(O-benzyloxime)] and ethyl ketone, 1-[9-ethyl -6-(2-Methylbenzyl)-9H-carbazol-3-yl]-,1-(O-acetyloxime) and other oxime ester-based photopolymerization initiators; and sulfonate-based The photopolymerization initiator and the like are preferably phosphine oxide-based photopolymerization initiators and oxime ester-based photopolymerization initiators. A photopolymerization initiator may be used individually by 1 type, and may use 2 or more types together.

Examples of commercially available photopolymerization initiators include "IRGACURE 819" (bis(2,4,6-trimethylbenzyl)-phenylphosphine oxide) manufactured by BASF JAPAN Co., Ltd., IRGACURE 907" (2-methyl-[4-(methylthio)phenyl]-morpholin-1-propanone), "OXE-01" (1,2-octanedione, 1-〔 4-(phenylthio)-,2-(O-benzyl oxime)]), "OXE-02" (ethyl ketone, 1-(9-ethyl-6-(2-methylbenzene) Formyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime)) and the like.

The content of the photopolymerization initiator in the resin composition is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and still more preferably 0.3 from the viewpoint of obtaining good photocuring characteristics and insulation reliability. Above mass%. The upper limit of the content of the photopolymerization initiator is preferably 2% by mass or less, more preferably 1.5% by mass or less, and still more preferably 1% by mass or less from the viewpoint of preventing the reduction in dimensional stability due to excessive sensitivity .

-(e) Light sensitizer-

In terms of photosensitizers, for example, tertiary amines, pyrarizones, anthracenes, coumarins, xanthones, thioxanthones, etc., are preferred, and thioxanthones are preferred. 2,4-Diethylthioxanthone is more preferred. A photosensitizer may be used individually by 1 type, and may use 2 or more types together. Examples of commercially available photosensitizers include "DETX-S" (2,4-diethylthioxanthone) manufactured by Nippon Kayaku Co., Ltd.

The content of the photosensitizer in the resin composition is preferably 0.01% by mass to 1% by mass, more preferably 0.05% by mass to 0.5% by mass, from the viewpoint of obtaining good photocuring properties.

-(f) Thinner-

The diluent is used to promote the photohardening reaction of the resin composition. As for the diluent, for example, a photosensitive (meth)acrylate compound having one or more (meth)acrylic groups in the molecule is liquid, solid, or semi-solid at room temperature.

Representative photosensitive (meth)acrylate compounds include, for example, hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxybutyl acrylate; ethylene glycol, methoxytetraethylene Mono- or diacrylates of glycol compounds such as alcohol, polyethylene glycol, propylene glycol, tricyclodecane dimethanol, etc.; propylene such as N,N-dimethyl acrylamide, N-methylol acrylamide, etc. Amides; N,N-dimethylaminoethyl acrylate and other amino alkyl acrylates; trimethylolpropane, pentaerythritol, dipentaerythritol, etc. polyols or these ethylene oxide and propylene oxide Or polyvalent acrylic esters of adducts of ε-caprolactone; phenols such as phenoxy acrylate and phenoxyethyl acrylate or acrylic esters of ethylene oxide or propylene oxide adducts; Epoxy acrylates derived from glycidyl ethers such as trimethylolpropane triglycidyl ether; melamine acrylates; and/or methacrylates corresponding to the above-mentioned acrylates. Among them, mono- or di(meth)acrylates and polyvalent (meth)acrylates of diol compounds are more preferred.

A diluent may be used individually by 1 type, and may use 2 or more types together. Commercially available diluents include, for example, Nippon Kayaku Co., Ltd. "DPHA" (dipentaerythritol hexaacrylate), and "DCPA" (tricyclodecane dimethanol diacrylate) manufactured by Kyoeisha Chemical Industry Co., Ltd. )Wait.

The content of the diluent in the resin composition is preferably 0.5% by mass to 10% by mass, more preferably 2% by mass to 8% by mass, from the viewpoint of promoting the photocuring reaction and preventing adhesion of the cured product.

-(g) Inorganic filler-

Inorganic fillers include, for example, silica, alumina, glass, vernixite, silicate, barium sulfate, talc, clay, mica powder, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, Boron nitride, aluminum nitride, manganese nitride, aluminum borate, barium titanate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, barium zirconate, calcium zirconate, zirconium phosphate, and Zirconium tungstate phosphate, etc. Among these, silicon oxides such as amorphous silicon oxide, molten silicon oxide, crystalline silicon oxide, synthetic silicon oxide, and hollow silicon oxide are particularly preferred. In terms of silica, spherical silica is preferred. An inorganic filler may be used individually by 1 type, and may be used in combination of 2 or more types. Commercially available spherical molten silica, for example, "SOC1", "SOC2", "SOC3" and "SOC4" manufactured by Admatechs, "UFP-30" and "UFP- 80".

The average particle diameter of the inorganic filler is not particularly limited, and may be appropriately determined in accordance with the desired characteristics. From the viewpoint of improving the dispersibility of the inorganic filler, the average particle diameter of the inorganic filler is preferably 0.01 μm or more, more preferably 0.05 μm or more. From the viewpoint of obtaining sufficient insulation reliability, the average particle diameter of the inorganic filler is preferably 4 μm or less, more preferably 3 μm or less, still more preferably 2 μm or less, and still more preferably 1 μm or less. In addition, when the resin composition is a photocurable resin composition, the upper limit of the average particle size of the inorganic filler is preferably 1 μm or less, more preferably 0.8 μm or less from the viewpoint of obtaining good photocuring characteristics. It is still more preferably 0.6 μm or less or 0.4 μm or less. The average particle size of the inorganic filler is determined by the laser diffraction and scattering method based on the Mie scattering theory. Specifically, with the laser diffraction scattering type particle size distribution measuring device, the particle size distribution of the inorganic filler can be created on a volume basis, and the median diameter is taken as the average particle size for measurement. For the measurement sample, it is preferable to disperse the inorganic filler in water by ultrasonic waves. For laser diffraction scattering particle size distribution measuring devices, "LA-500" manufactured by Horiba Manufacturing Co., Ltd. can be used.

Inorganic fillers, from the viewpoint of improving moisture resistance and dispersibility, can be used amino silane coupling agent, epoxy silane coupling agent, mercapto silane coupling agent, silane coupling agent, organosilazane compound One or more surface treatment agents such as titanate coupling agents are preferred. Commercially available surface treatment agents include "KBM403" (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., and "KBM803" manufactured by Shin-Etsu Chemical Co., Ltd. (3 -Mercaptopropyltrimethoxysilane), "KBE903" (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., and "KBM573" (N-phenyl-) manufactured by Shin-Etsu Chemical Co., Ltd. 3-Aminopropyltrimethoxysilane), "SZ-31" (hexamethyldisilazane) manufactured by Shin-Etsu Chemical Co., Ltd., etc.

The degree of surface treatment achieved 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, from the viewpoint of improving the dispersibility 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 or more Better still. On the other hand, from the viewpoint of preventing the melt viscosity of the resin paint or the melt viscosity in the sheet form from increasing, it is preferably 1mg/m ² or less, more preferably 0.8mg/m ² or less, 0.5mg/m ² The following is even better.

The carbon content 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, in terms of solvents, a sufficient amount of MEK can be added to an inorganic filler that has been surface-treated with a surface treatment agent, and ultrasonically cleaned at 25°C for 5 minutes. After removing the supernatant and drying the solid content, the carbon content per unit surface area of the inorganic filler is measured using a carbon analyzer. For carbon analyzers, "EMIA-320V" manufactured by Horiba Manufacturing Co., Ltd. can be used.

The content of the inorganic filler in the resin composition is not particularly limited as long as a solder resist layer showing a desired elastic modulus can be obtained. Although it depends on the type of epoxy resin or curing agent, if the content of the inorganic filler in the resin composition is increased, the modulus of elasticity of the resin composition after curing tends to increase. For example, a resin composition layer exhibiting a high elastic modulus (23° C.) of 6 GPa or more after curing, and when the solder resist layer is formed, the content of the inorganic filler in the resin composition is preferably 60% by mass or more. A resin composition layer with a higher modulus of elasticity (23°C) after curing, and when the solder resist layer is formed, the content of the inorganic filler in the resin composition should be 65% by mass or more, preferably 70% by mass or more Or more preferably 75% by mass.

In one embodiment, the content of the inorganic filler in the resin composition used in the first resin composition layer and the first solder resist layer is preferably 60% by mass or more, more preferably 65% by mass or more, and still more It is preferably 70% by mass or more or 75% by mass or more. The upper limit of the content of the inorganic filler in the resin composition used in the first resin composition layer is not particularly limited. From the viewpoint of the mechanical strength of the resulting solder resist layer, it is usually 95% by mass or less, which may be 90% by mass or less.

The second resin composition layer and the content of the inorganic filler in the resin composition used in the second solder resist layer can be adapted to the case where a second solder resist layer capable of exhibiting the desired elastic modulus can be obtained The desired characteristics may be appropriately determined, and the range is preferably 0% by mass to 95% by mass, more preferably 20% by mass to 85% by mass.

In a preferred embodiment, the resin composition used in the first resin composition layer is a thermosetting resin composition, and contains the above-mentioned (a) epoxy resin, (b) hardener, and (g) inorganic Filling material. In this embodiment, the thermosetting resin composition used in the first resin composition layer preferably contains the following components: (a) liquid epoxy resin and solid epoxy resin. The mixture of resins (the mass ratio of liquid epoxy resin: solid epoxy resin is preferably in the range of 1:0.1~1:4, preferably in the range of 1:0.3~1:3.5, and 1:0.6~ The range of 1:3 is more preferable, and the range of 1:0.8~1:2.5 is even more preferable. (b) The hardener consists of phenol hardener, naphthol hardener, active ester hardener and cyanic acid One or more selected from the group of ester-based curing agents (preferably one or more selected from the group of phenol-based curing agents, naphthol-based curing agents, and active ester-based curing agents), as (g) Silica as an inorganic filler. Regarding the thermosetting resin composition comprising the combination of the specific components, the preferable contents of (a) epoxy resin, (b) hardener, and (g) inorganic filler are as described above.

In another preferred embodiment, the resin composition used in the first resin composition layer is a photocurable resin composition, the above-mentioned (a) epoxy resin, (b) curing agent, and (c) photocuring type The alkali contains a soluble resin and (g) an inorganic filler. In this embodiment, the photocurable resin composition used in the first resin composition layer preferably contains the following components: (a) Liquid epoxy resin and solid epoxy resin as epoxy resin The resulting mixture (the mass ratio of liquid epoxy resin: solid epoxy resin is preferably in the range of 1:0.1~1:4, preferably in the range of 1:0.3~1:3.5, and 1:0.6~1 : The range of 3 is better, and the range of 1:0.8~1:2.5 is even better) or only solid epoxy resin, as (b) the hardener is a phenol hardener, naphthol hardener, and active One or more selected from the group consisting of ester curing agents and cyanate ester curing agents (preferably one or more selected from the group consisting of phenol curing agents, naphthol curing agents, and active ester curing agents ), as (c) photocurable alkali-soluble resins containing alkali-soluble groups and radically polymerizable unsaturated groups (preferably resins containing carboxyl groups and radically polymerizable unsaturated groups, phenolic hydroxyl groups and A resin with a radically polymerizable unsaturated group, more preferably a resin containing a phenolic hydroxyl group and a radically polymerizable unsaturated group), (g) silica as an inorganic filler. Regarding the preferable content of a thermosetting resin composition composed of a combination of the specific components, (a) epoxy resin, (b) hardener, (c) photo-curable alkali-soluble resin, and (g) inorganic filler Same as above, but from the viewpoint of obtaining good heat resistance, insulation reliability, and developability, when the non-volatile content of (c) photocurable alkali-soluble resin is 100% by mass, (a) ring The oxygen resin is preferably 5% by mass to 100% by mass, more preferably 10% by mass to 85% by mass. In addition, when the resin composition used in the first resin composition layer is a photocurable resin composition, the photocurable resin composition may further contain (d) a photopolymerization initiator and (e) a photopolymerization initiator. One or more selected from the group of sensitizers and (f) diluents is preferable.

From the viewpoint of suppressing the warpage of the printed wiring board in the mounting step, the resin composition used in the first resin composition layer and the first solder resist layer does not matter whether the thermosetting resin composition or the photocuring resin For the type of composition, the glass transition temperature (Tg) after curing is preferably 150°C or higher, and more preferably 155°C or higher. The upper limit of the Tg is not particularly limited, but it is usually 300°C or lower, and may be 250°C or lower. The Tg system of the cured resin composition can be measured by thermomechanical analysis by the tensile-weight method. In the measurement of the Tg of the cured resin composition, thermomechanical analysis devices that can be used include, for example, "Thermo Plus TMA8310" manufactured by Rigaku Corporation and "TMA-SS6100" manufactured by Seiko Instruments.

In a preferred embodiment, the resin composition used in the second resin composition layer is a thermosetting resin composition containing the above-mentioned (a) epoxy resin and (b) curing agent. In this embodiment, the thermosetting resin composition used in the second resin composition layer preferably contains each of the following components: (a) epoxy resin, liquid epoxy resin and solid epoxy resin The resulting mixture (the mass ratio of liquid epoxy resin: solid epoxy resin is preferably in the range of 1:0.1~1:4, preferably in the range of 1:0.3~1:3.5, and 1:0.6~1 : The range of 3 is more preferable, and the range of 1:0.8~1:2.5 is even more preferable. (b) Hardeners include phenol hardeners, naphthol hardeners, active ester hardeners and cyanic acid One or more selected from the group of ester-based curing agents (preferably one or more selected from the group of phenol-based curing agents, naphthol-based curing agents, and active ester-based curing agents). Regarding the thermosetting resin composition containing the combination of the specific components, the preferable contents of (a) epoxy resin and (b) hardener are also as described above. The thermosetting resin composition used in the second resin composition layer is also the same as described above. In order to achieve the second solder resist layer exhibiting the desired elastic modulus, it contains (g) an inorganic filler (preferably silicon oxide) The content in the resin composition is in the range of 0% by mass to 95% by mass. Here, the "contained in the range of 0% by mass to n% by mass" regarding the constituent components of the resin composition includes both the case where the constituent component is not contained and the case where it is contained in the range of n mass% or less.

In another preferred embodiment, the resin composition used in the second resin composition layer is a photocurable resin composition, and contains the above-mentioned (a) epoxy resin, (b) curing agent, and (c) light Hardening type alkali-soluble resin. In this embodiment, the photocurable resin composition used in the second resin composition layer preferably contains the following components: (a) liquid epoxy resin and solid epoxy resin as epoxy resin The resulting mixture (the mass ratio of liquid epoxy resin: solid epoxy resin is preferably in the range of 1:0.1~1:4, preferably in the range of 1:0.3~1:3.5, and 1:0.6~1 : The range of 3 is even better, and the range of 1:0.8~1:2.5 is even better) or only solid epoxy resin, as (b) the hardener is a phenol hardener, naphthol hardener, One or more selected from the group of active ester curing agents and cyanate ester curing agents (preferably one selected from the group of phenol curing agents, naphthol curing agents, and active ester curing agents Above), as (c) photocurable alkali-soluble resin, a resin containing an alkali soluble group and a radically polymerizable unsaturated group (preferably a resin containing a carboxyl group and a radically polymerizable unsaturated group, a phenolic hydroxyl group A resin with a radically polymerizable unsaturated group is more preferably a resin containing a phenolic hydroxyl group and a radically polymerizable unsaturated group). Regarding the thermosetting resin composition containing the combination of the specific components, the preferable contents of (a) epoxy resin, (b) hardener, and (c) photo-curable alkali-soluble resin are as described above, but they are good From the viewpoints of heat resistance, insulation reliability and developability of (a) epoxy resin, when the non-volatile content of (c) photo-curing alkali-soluble resin is 100% by mass, it is preferably 5% by mass ~100% by mass, more preferably 10% by mass to 85% by mass. When the resin composition used in the second resin composition layer is a photocurable resin composition, the photocurable resin composition system may further include (d) a photopolymerization initiator and (e) photosensitization. One or more selected from the group of (f) diluent is preferred. The photocurable resin composition used in the second resin composition layer is also the same as described above. In order to achieve the second solder resist layer exhibiting the desired elastic modulus, the content of the resin composition is 0 to 95% by mass. The range contains (g) an inorganic filler (preferably silicon oxide).

Regardless of the type of thermosetting resin composition or photocuring resin composition, the resin composition used in the second resin composition layer and the second solder resist layer, as long as the desired elastic modulus is obtained, will be cured after curing The glass transition temperature (Tg) is not particularly limited. From the viewpoint of suppressing the warpage of the printed wiring board during the mounting step, the resin composition used in the second resin composition layer and the second solder resist layer has a cured Tg of 150°C or higher. Good, more preferably above 155℃. The upper limit of the Tg is not particularly limited, but it is usually 300°C or lower, and may be 250°C or lower.

In a preferred embodiment, the resin compositions used in the first and second resin composition layers are both thermosetting resin compositions. In other preferred embodiments, the resin compositions used in the first and second resin composition layers are both photocurable resin compositions. Furthermore, in other preferred embodiments, the resin composition used in the first resin composition layer is a thermosetting resin composition, and the resin composition used in the second resin composition layer is a photocurable resin composition Things. In other preferred embodiments, the resin composition used in the first resin composition layer is a photocurable resin composition, and the resin composition used in the second resin composition layer is a thermosetting resin composition.

-(h) Thermoplastic resin-

The resin composition used in the first and second resin composition layers may further include a thermoplastic resin. Regarding the thermoplastic resin, when forming the solder resist layer of the printed wiring board, any generally available thermoplastic resin can be used, such as phenoxy resin, polyvinyl acetal resin, polyolefin resin, polybutadiene Resin, polyimide resin, polyimide resin, polyether ether resin, polyphenylene ether resin, polyimide resin, etc. Thermoplastic resin can be used individually by 1 type or in combination of 2 or more types.

The weight average molecular weight of the thermoplastic resin converted to polystyrene is preferably in the range of 8,000 to 70,000, more preferably in the range of 10,000 to 60,000, and even more preferably in the range of 20,000 to 60,000. The weight average molecular weight in terms of polystyrene of the thermoplastic resin is measured by the gel permeation chromatography (GPC) method. Specifically, the weight average molecular weight in terms of polystyrene of the thermoplastic resin is measured using LC-9A/RID-6A manufactured by Shimadzu Corporation as the measuring device, and Shodex K-800P/ manufactured by Showa Denko Corporation For K-804L/K-804L, the mobile phase uses chloroform, etc., and the column temperature is measured at 40°C, and it is calculated using the calibration curve of standard polystyrene.

The content of the thermoplastic resin in the resin composition is not particularly limited as long as a solder resist layer exhibiting the desired elastic modulus can be obtained. It is preferably 0.1% by mass or more, more preferably 1% by mass or more, and still more preferably 3 Mass% or more, 5 mass% or more, or 7 mass% or more. The upper limit of the content of the thermoplastic resin is not particularly limited, but is preferably 50% by mass or less, more preferably 40% by mass or less, and still more preferably 30% by mass or less. Although it depends on the type of epoxy resin or curing agent, and the content of the inorganic filler, if the content of the thermoplastic resin in the resin composition is increased, the modulus of elasticity after curing of the resin composition tends to decrease.

-(i) Hardening accelerator-

The resin composition used in the first and second resin composition layers may further include a curing accelerator. Regarding the hardening accelerator, when forming the solder resist layer of the printed wiring board, any hardening accelerator generally used may be used. Examples include phosphorus hardening accelerators, amine hardening accelerators, and imidazole hardening accelerators. , Guanidine hardening accelerators, etc., preferably phosphorus hardening accelerators, amine hardening accelerators, and imidazole hardening accelerators, more preferably amine hardening accelerators and imidazole hardening accelerators. The hardening accelerator system may be used alone or in combination of two or more kinds.

The content of the hardening accelerator in the resin composition is not particularly limited as long as a solder resist layer exhibiting the desired elastic modulus can be obtained. When the total amount of the non-volatile components of the epoxy resin and the hardener is 100% by mass, it is It is better to use in the range of 0.03% to 3% by mass.

-(j) Flame retardant-

The resin composition used in the first and second resin composition layers may further include a flame retardant. Regarding the flame retardant, any flame retardant generally used can be used when forming the solder resist layer of the printed wiring board. Examples include organic phosphorus flame retardants, organic nitrogen-containing phosphorus compounds, nitrogen compounds, and silicone-based flame retardants. Flame retardant, metal hydroxide, etc. The flame retardant may be used alone or in combination of two or more. The content of the flame retardant in the resin composition is not particularly limited as long as a solder resist layer showing the desired elastic modulus can be obtained, and it is preferably 0.5% by mass to 20% by mass, more preferably 1% by mass to 15% by mass .

-(k) Organic filler material-

The resin composition used in the first and second resin composition layers may further include an organic filler. Regarding the organic filler, when forming the solder resist layer of the printed wiring board, any organic filler generally used can be used, such as rubber particles, polyamide microparticles, polysiloxane particles, etc., preferably rubber particles.

The rubber particles are not particularly limited as long as they are fine particles of a resin that is chemically crosslinked to exhibit rubber elasticity and are insoluble and infusible to organic solvents. Examples include acrylonitrile butadiene rubber. Particles, butadiene rubber particles, acrylic rubber particles, etc. For rubber particles, specifically, XER-91 (manufactured by Nippon Synthetic Rubber Co., Ltd.), Staphiroid AC3355, AC3816, AC3816N, AC3832, AC4030, AC3364, IM101 (above, manufactured by GANTSU KASEI Co., Ltd.) Pararoid EXL2655, EXL2602 ( Above, Kureha Chemical Industry Co., Ltd.), etc.

The average particle diameter of the organic filler is preferably in the range of 0.005 μm to 1 μm, more preferably in the range of 0.2 μm to 0.6 μm. The average particle size of the organic filler can be measured using a dynamic light scattering method. For example, the organic filler can be uniformly dispersed by ultrasonic waves in a suitable organic solvent, and the organic filler can be made on the basis of quality by using a dense particle size analyzer (FPAR-1000; manufactured by Otsuka Electronics Co., Ltd.) For the particle size distribution, the median diameter is taken as the average particle size for measurement.

The content of the organic filler in the resin composition is not particularly limited as long as a solder resist layer showing the desired elastic modulus can be obtained, and it is preferably 0.1% by mass to 6% by mass, more preferably 0.5% by mass to 4% by mass .

-Other ingredients-

The resin composition used in the first and second resin composition layers may optionally contain other additives. The other additives include, for example, organometallic compounds such as organic copper compounds, organic zinc compounds, and organic cobalt compounds, and Resin additives such as tackifiers, defoamers, leveling agents, adhesion imparting agents, and coloring agents.

<Support body>

Regarding the support, regardless of the difference between the first support and the second support, for example, films made of plastic materials, metal foils, and release papers can be cited, and films made of plastic materials or metal foils are preferred.

As for the support, when a film made of a plastic material is used, as for the plastic material, for example, polyethylene terephthalate (hereinafter referred to as "PET"), polyethylene naphthalate (hereinafter referred to as " PEN”) and other polyesters, polycarbonate (hereinafter referred to as “PC”), polymethylmethacrylate (PMMA) and other acrylates, cyclic polyolefins, triacetyl cellulose (TAC), poly Ether sulfide (PES), polyether ketone, polyimide, etc. Among them, polyethylene terephthalate and polyethylene naphthalate are more preferred, and polyethylene terephthalate is particularly preferred.

As for the support, when using metal foil, examples of the metal foil include copper foil and aluminum foil, and copper foil is preferred. As for copper foil, a foil made of a single metal of copper can 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.) can be used.

The support may be subjected to matting treatment or corona treatment on the surface joined with the resin composition layer. In addition, as for the support, a support with a release layer having a release layer on the surface bonded to the resin composition layer can also be used. The release agent used on the release layer of the support with the release layer includes, for example, alkyd resins, polyolefin resins, urethane resins, and silicone resins. More than one release agent.

The commercial products of the support include, for example, "SK-1", "AL-5", "AL-7" manufactured by LINTEC, "NS80A" manufactured by Toray Co., Ltd., and manufactured by Mitsubishi Plastics Co., Ltd. "R310-16B" and so on.

The thickness of the support 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, and even more preferably in the range of 10 μm to 45 μm. In addition, when a support with a release layer is used, the thickness of the entire support with a release layer is preferably within the above range.

For the resin sheet, regardless of the difference between the first resin sheet and the second resin sheet, for example, the resin composition can be prepared by dissolving the resin composition in an organic solvent to prepare a resin coating, and the resin coating can be applied to the support using a die coater, etc Body, and make the resin paint dry.

In terms of organic solvents, for example, ketones such as acetone, methyl ethyl ketone and cyclohexanone, ethyl anionate, butyl anionate, ceroxol acetate, propylene glycol monomethyl ether acetate and carbitol Acetic acid esters such as acetic acid esters, carbitols such as xyloxol and butyl carbitol, aromatic hydrocarbons such as toluene and xylene, dimethylformamide, dimethylacetamide and Amide solvents such as N-methylpyrrolidone. An organic solvent can be used individually by 1 type or in combination of 2 or more types.

The drying of the resin paint can be performed by a known drying method such as heating and hot air blowing. Although it also depends on the boiling point of the organic solvent in the resin paint, for example, when using a resin paint containing 30% to 60% by mass of an organic solvent, it can be dried at 50°C to 150°C for 3 minutes ~10 minutes to form a resin composition layer on the support.

Regardless of the difference between the first resin sheet and the second resin sheet, the resin sheet may further include a protective film on the surface of the resin composition layer that is not bonded to the support (that is, the surface opposite to the support). The protective film acts to prevent the adhesion or damage of dirt on the surface of the resin composition layer. As for the material of the protective film, the same materials as those described for the support can be used. The thickness of the protective film is not particularly limited, and is, for example, 1 μm to 40 μm. The resin sheet is used by peeling off the protective film when manufacturing printed wiring boards.

[Method of Manufacturing Printed Wiring Board]

In the case where a printed wiring board satisfying the aforementioned conditions (1), (2), and (3) can be obtained, the method of manufacturing the printed wiring board of the present invention is not particularly limited. Hereinafter, the method of manufacturing a printed wiring board using the resin sheet for the solder resist layer of the above-mentioned printed wiring board is demonstrated as a preferable example of the method of manufacturing the printed wiring board of this invention.

In a preferred embodiment, the printed wiring board of the present invention uses the resin sheet set for the solder resist layer of the printed wiring board described above, and is manufactured by a method including the following steps (I) to (III).

(I) On the first main surface of the circuit board having the first and second main surfaces, a first resin sheet including a first support and a first resin composition layer bonded to the first support is applied to Step of laminating the first resin composition layer and the first main surface of the circuit board

(II) On the second main surface of the circuit board, a second resin sheet including a second support and a second resin composition layer bonded to the second support is formed with the second resin composition layer and the circuit board Steps of lamination by joining the second main surface

(III) Step of hardening the first and second resin composition layers to form the first and second solder resist layers

-Step (I)-

In step (I), on the first main surface of the circuit board having the first and second main surfaces, the first resin including the first support and the first resin composition layer bonded to the first support The sheet is laminated so that the first resin composition layer is bonded to the first main surface of the circuit board.

In the step (I), the first resin sheet used is as described in the above [Resin Sheet Group for Solder Resist Layer of Printed Wiring Board].

In the present invention, the term "circuit board" refers to a board on which solder resist layers are formed on both sides of the printed wiring board. For example, it has opposing first and second main surfaces and is placed on the first and second main surfaces. 2A board with patterned circuit wiring on both main surfaces. The layer structure including the number of layers of circuit wiring is not particularly limited, and may be appropriately determined depending on the characteristics of the desired printed wiring board.

The thickness of the circuit board is not particularly limited when a printed wiring board that satisfies the above conditions (1) and (2) can be obtained. It is preferably 240 μm or less, more preferably 220 μm or less, and even more preferably 200 μm or less. According to the present invention, even when a thinner circuit board is used, the warpage of the printed wiring board in the mounting step can be suppressed. Even when a circuit board with a thickness of 190 μm or less, 180 μm or less, 170 μm or less, 160 μm or less, 150 μm or less, 140 μm or less, 130 μm or less, 120 μm or less, 110 μm or less, or 100 μm or less is used, the mounting step can be suppressed. Warped. The lower limit of the thickness of the circuit board is not particularly limited. From the viewpoint of improving the drawability during the manufacture of the printed wiring board, it is preferably 10 μm or more, and more preferably 20 μm or more. In addition, the thickness of the circuit board refers to the thickness of the entire circuit board including the thickness of the surface circuit. Here, when the value obtained by subtracting the thickness of the surface circuit from the thickness of the circuit board is t ₃ (μm), the above-mentioned Z, t ₁ , t ₂ and the t ₃ satisfy the value of t ₁ +t ₂ +t ₃ =Z relationship.

The thickness of the surface circuit of the circuit board is not particularly limited. From the viewpoint of thinning the printed wiring board, it is preferably 40 μm or less, more preferably 30 μm or less, still more preferably 25 μm or less, and still more preferably 20 μm Below, 18 μm or less, 16 μm or less, 14 μm or less, 12 μm or less, or 10 μm or less. The lower limit of the thickness of the surface circuit is not particularly limited, and it can usually be 1 μm or more, 3 μm or more, or 5 μm or more.

The thermal expansion coefficient of the circuit board is preferably 16 ppm/°C or less, more preferably 14 ppm/°C or less, and still more preferably 12 ppm/°C or less from the viewpoint of suppressing the generation of circuit distortion or cracks. Although the lower limit of the thermal expansion coefficient of the circuit board depends on the composition of the resin composition used in the formation of the solder resist layer, it is preferably -2ppm/°C or more, more preferably 0ppm/°C or more, and still more preferably 4ppm/°C the above. In the present invention, the thermal expansion coefficient of the circuit board is a linear thermal expansion coefficient of 25 to 150° C. in the plane direction obtained by thermomechanical analysis (TMA) using the tension-weight method. Examples of thermomechanical analysis devices that can be used for measuring the linear thermal expansion coefficient of circuit boards include "Thermo Plus TMA8310" manufactured by Rigaku Corporation and "TMA-SS6100" manufactured by Seiko Instruments.

The bending elastic modulus of the circuit board is not particularly limited. In the present invention, regardless of the bending elastic modulus of the circuit board, it is possible to suppress warpage in the mounting step.

The stacking of the circuit board and the first resin sheet can be carried out, for example, by heating and pressing the first resin sheet to the circuit board from the side of the first support. The member for heating and pressing the first resin sheet to the circuit board (hereinafter also referred to as "heat pressing member") includes, for example, a heated metal plate (SUS mirror plate, etc.) or metal roller (SUS roller). In addition, the heating and pressing member is not directly pressed on the first resin sheet, but is caused by the unevenness of the circuit on the surface of the circuit board, and the first resin sheet is fully followed by an elastic material such as heat-resistant rubber. Pressure is better.

The heating and pressing temperature is preferably in the range of 80°C to 160°C, more preferably in the range of 100°C to 140°C, and the heating and pressing pressure is preferably in the range of 0.098MPa to 1.77MPa, more preferably 0.29MPa to 1.47MPa, The heating and pressing time is preferably in the range of 20 seconds to 400 seconds, more preferably 30 seconds to 300 seconds. Laminating is preferably carried out under reduced pressure of 26.7 hPa or less.

The layering system can be carried out by a commercially available vacuum layering machine. Commercially available vacuum laminators include, for example, a vacuum pressurized laminator manufactured by Meiji Seisakusho Co., Ltd., and a vacuum applicator manufactured by Nichigo-Morton Co., Ltd., and the like.

After the lamination, under normal pressure (under atmospheric pressure), for example, the layered first adhesive sheet is smoothed by pressing a heating and pressing member from the side of the first support. The pressing conditions of the smoothing treatment may be the same conditions as the heating and pressing conditions of the aforementioned build-up. The smoothing process can be implemented by a commercially available laminate machine. In addition, the layering and smoothing treatment can also be continuously performed using the above-mentioned commercially available vacuum layering machine.

-Step (II)-

In step (II), on the second main surface of the circuit board, a second resin sheet including a second support and a second resin composition layer bonded to the second support is formed with a second resin composition layer It is laminated to the second main surface of the circuit board.

In the step (II), the second resin sheet used is as described in the above [Resin Sheet Group for Solder Resist Layer of Printed Wiring Board].

The stacking of the circuit board and the second resin sheet can be carried out in the same manner as in step (I). After the circuit board and the second resin sheet are laminated, the smoothing treatment described in step (I) can be applied to the second resin sheet.

Step (I) and step (II) can be carried out simultaneously using a commercially available vacuum stacker.

The first and second supports can be removed before step (III). Or, the first and second supports may be removed after step (III) (in the case of using a thermosetting resin composition layer), or between steps (III) (using a photocurable resin composition layer) Case).

-Step (III)-

In step (III), the first and second resin composition layers are cured to form the first and second solder resist layers.

The curing conditions of the resin composition layer are not particularly limited, and conditions generally used when forming the solder resist layer of a printed wiring board may be used.

When at least one of the first and second resin composition layers is a thermosetting resin composition layer, step (III) includes thermosetting the thermosetting resin composition layer to form a solder resist layer.

The conditions of thermosetting vary depending on the composition of the resin composition used in the thermosetting resin composition layer. The curing temperature is in the range of 120°C to 240°C (preferably in the range of 150°C to 210°C, more preferably The range of 170°C to 190°C), the curing time is in the range of 5 minutes to 150 minutes (preferably 10 minutes to 120 minutes, more preferably 15 minutes to 90 minutes). Thermal hardening is preferably carried out under atmospheric pressure (under normal pressure). In addition, thermal hardening can be performed multiple times. For example, step (III) can be performed multiple times before step (IV) described below, step (III) can be performed more than once before step (IV) described below, and step (IV) and (V) can be performed after step (IV) and (V). More than one thermal hardening. When thermal curing is performed n times, the aforementioned "modulus of elasticity after curing" means the elastic modulus after thermal curing is performed n times.

When at least one of the first and second resin composition layers is a photocurable resin composition layer, step (III) includes exposing, developing, and baking the photocurable resin composition layer to form a solder resist layer.

Exposure of the photocurable resin composition layer can be carried out by irradiating a predetermined part of the photocurable resin composition layer with active light using a mask pattern, for example. Thereby, the photocurable resin composition in the irradiated part can be photocured. In terms of active light, for example, ultraviolet rays, visible rays, electron rays, X-rays, etc. can be mentioned, and ultraviolet rays are particularly preferred. The irradiation amount of ultraviolet rays is not particularly limited, and may be a range generally used when a photocurable resin composition is used to form a solder resist layer, but it is preferably 10 mJ/cm ² to 1000 mJ/cm ² . When there is a support on the photocurable resin composition layer, the light can be exposed from the support.

The imaging system uses a developing solution, and it can also be implemented after removing the uncured part (unexposed part). In this way, the desired pattern can be formed. In addition, if there is a support on the photocurable resin composition layer, the support can be removed and then developed. As for the developer, an alkaline developer is preferable, and examples include sodium carbonate aqueous solution and sodium hydroxide aqueous solution. The development method includes, for example, spraying, shaking dipping, wiping, and scraping.

Although the baking conditions vary depending on the composition of the resin composition used in the photocurable resin composition layer, the baking temperature can be in the range of 120°C to 240°C (preferably in the range of 150°C to 210°C, It is more preferably in the range of 170°C to 190°C), and the baking time can be in the range of 5 minutes to 150 minutes (preferably 10 minutes to 120 minutes, more preferably 15 minutes to 90 minutes). Baking is preferably carried out under atmospheric pressure (under normal pressure). In addition, baking can be performed multiple times. When baking is performed n times, the aforementioned "modulus of elasticity after curing" means the modulus of elasticity after n baking is performed.

When one side of the first and second resin composition layers is the thermosetting resin composition layer, and the other side is the photocuring resin composition layer, the photocurable resin composition layer is baked to be compatible with heat The thermal curing of the curable resin composition layer is performed simultaneously.

By using the resin sheet set of the present invention to implement steps (I) to (III), a printed wiring board satisfying the aforementioned conditions (1), (2) and (3) can be easily manufactured.

-Other steps-

The method of manufacturing a printed wiring board may further include (IV) a step of forming an opening, and (V) a step of electroless copper plating. These steps (IV) and (V) are used in the manufacture of printed wiring boards, and can be implemented according to various methods known to those skilled in the field. In addition, when the first and second supports are peeled off after step (III) (in the case of using a thermosetting resin composition layer), the first and second supports can be peeled off in step (III) and step It is carried out between (IV), between step (IV) and step (V), or after step (V).

Step (IV) is a step of forming an opening. Thereby, an opening can be formed in the solder resist layer formed using the thermosetting resin composition. In addition, if necessary, in order to form an opening in the solder resist layer formed using the photocurable resin composition, step (IV) may be implemented. Step (IV) can be implemented using, for example, drilling, laser, plasma, etc., in accordance with the composition of the resin composition constituting the solder resist layer. The size or shape of the opening can be appropriately determined depending on the design of the component mounting substrate (also referred to as "semiconductor device").

When the opening is formed by a laser, the laser light source includes, for example, a carbon dioxide laser, YAG laser, and excimer laser. Among them, from the viewpoint of processing speed and cost, a carbon dioxide laser is preferred.

Step (V) is a step of electroless copper plating treatment. In step (IV), resin residues (stains) generally adhere to the inside of the formed opening. This stain will become a cause of poor electrical connection. Therefore, in step (V), stain removal treatment (electroless copper plating treatment) is performed.

The electroless copper plating treatment can be implemented by combining dry electroless copper plating treatment, wet electroless copper plating treatment or a combination of these.

For dry electroless copper plating, for example, electroless copper plating using plasma can be mentioned. The electroless copper plating treatment system using plasma can be implemented using a commercially available plasma electroless copper plating processing device. Among commercially available plasma electroless copper plating processing equipment, more preferable examples are used in the manufacture of printed wiring boards, such as microwave plasma equipment manufactured by Nissin and Sekisui Chemical Industry Co., Ltd. Atmospheric pressure plasma etching equipment, etc.

For the wet electroless copper plating treatment, for example, an electroless copper plating treatment using an oxidizing agent solution can be mentioned. When an oxidant solution is used for electroless copper plating treatment, it is better to sequentially perform swelling treatment with swelling solution, oxidation treatment with oxidant solution, and neutralization treatment with neutralization solution. Examples of swelling fluids include "Swelling Dip Securiganth P" and "Swelling Dip Securiganth SBU" manufactured by ATOTECH JAPAN. The swelling treatment is preferably performed by heating the substrate with the opening to 60°C to 80°C and immersing it in the swelling solution for 5 to 10 minutes. Regarding the oxidizing agent solution, an alkaline permanganic acid aqueous solution is preferred, for example, a solution in which potassium permanganate and sodium permanganate are dissolved in an aqueous sodium hydroxide solution. The oxidation treatment with an oxidizing agent solution is preferably performed by immersing the swelled substrate in an oxidizing agent solution heated to 60°C to 80°C for 10 minutes to 30 minutes. Examples of commercially available alkaline permanganic acid aqueous solutions include "Concentrate Compact CP" and "Dosing Solution Securiganth P" manufactured by ATOTECH JAPAN. The neutralization treatment by the neutralization solution is preferably performed by immersing the substrate after oxidation treatment in a neutralization solution at 30°C to 50°C for 3 minutes to 10 minutes. As for the neutralization solution, an acidic aqueous solution is preferred. As for a commercially available product, for example, "Reduction Solution Securiganth P" manufactured by ATOTECH JAPAN Co., Ltd. can be mentioned.

When a combination of dry electroless copper treatment and wet electroless copper electroplating is implemented, dry electroless copper electroplating may be performed first, or wet electroless copper electroplating may be performed first.

Although the method of manufacturing a printed wiring board using the resin sheet set of the present invention has been described above, as long as it is possible to obtain a printed wiring board that satisfies the above conditions (1), (2) and (3), the printed wiring board of the present invention is manufactured The method of wiring boards is not particularly limited. For example, a resin composition lacquer can be applied to both surfaces of a circuit board, dried, and cured to manufacture a printed wiring board.

[Semiconductor Device]

A semiconductor device can be manufactured using the printed wiring board of the present invention. Even if the printed wiring board of the present invention is thin, it can suppress warpage in the mounting step of parts with high solder reflow temperature, which is beneficial to alleviate problems such as circuit distortion or poor contact of parts.

In terms of semiconductor devices, various semiconductor devices such as power supply products (for example, computers, mobile phones, digital cameras, and televisions) and vehicles (for example, motorcycles, automobiles, trams, ships, and airplanes) can be cited.

[Example]

Hereinafter, the present invention will be specifically explained through examples, but the present invention is not limited to these examples. In addition, "parts" and "%" in the following refer to "parts by mass" and "% by mass", unless otherwise clearly stated.

First, various measurement methods and evaluation methods will be explained.

[Preparation of evaluation substrate] (1) Preparation of circuit board

The glass cloth base epoxy resin two-area laminate with circuits formed on both sides is etched with a microetchant ("CZ8100" manufactured by MEC Co., Ltd.) for 1 μm, and the surface circuits are roughened to prepare a circuit board. Regarding the epoxy resin two-area laminate on a glass cloth base material with circuits formed on both sides, Examples 1, 2 and 4 and Comparative Examples 1 and 2 use Mitsubishi Gas Chemical Corporation "HL832NSF-LCA" (size 100mm×150mm) , Thickness 100μm, thermal expansion rate 4ppm/°C, flexural modulus 34GPa, surface copper circuit thickness 16μm), Example 3 and Comparative Examples 3 and 4 use Hitachi Chemical Co., Ltd. "E679FGR" (size 100mm×150mm, The thickness is 200 μm, the thermal expansion coefficient is 14 ppm/K, the flexural modulus is 26 GPa, and the thickness of the surface copper circuit is 16 μm (Example 3 and Comparative Example 3), 8 μm (Comparative Example 4)).

(2) Laminated resin sheet

The circuit board learned in (1) above is based on the following production example, using a batch-type vacuum pressure laminator (2 stage build-up laminator manufactured by Nichigo-Morton (stock) CVP700") is laminated on both sides of the circuit board in a way that the resin composition layer is bonded to the circuit board. After the layer was depressurized for 30 seconds and the air pressure was 13 hPa or less, it was pressed at 100° C. and 0.74 MPa for 30 seconds. Then, the smoothing process was performed by hot pressing under normal pressure, 100° C., and pressure of 0.5 MPa for 60 seconds.

In addition, the combination of the first and second resin sheets on the two area layers of the circuit board is shown in Table 1.

Next, as described below, the resin composition layer is cured to form a solder resist layer.

-When using resin sheets 1 and 2 containing a thermosetting resin composition layer- (3) Thermal curing of the resin composition layer

The support is peeled off from the substrate obtained in (2) above. Next, the resin composition layer was thermally cured under curing conditions of 180°C for 30 minutes to form a solder resist layer.

(4) Formation of opening

Using a CO ₂ laser processing machine (Mitsubishi Electric Corporation "ML605GTWIII-5200U"), a circular hole with an opening diameter of 60 μm was formed under the following condition 1 and a circular hole with an opening diameter of 500 μm was formed under the following condition 2.

Condition 1: Mask diameter 0.9mm, pulse width 19μs, energy 0.24mJ, number of shots 2, pulse intermittent mode

Condition 2: Mask diameter 10mm, pulse width 15μs, energy 18mJ, number of shots 4, pulse interval mode

(5) Electroless copper plating treatment

After the opening is formed, the circuit board is immersed in a swelling liquid (ATOTECH JAPAN "Swelling Dip Securiganth P", an aqueous solution containing diethylene glycol monobutyl ether and sodium hydroxide) at 60°C for 5 minutes. In the oxidant solution (ATOTECH JAPAN (stock) "Concentrate Compact CP", KMnO ₄ : 60g/L, NaOH: 40g/L aqueous solution) at 80°C for 10 minutes, and finally a neutralization solution (ATOTECH JAPAN (stock) Reduction Solution Securiganth P", hydroxylamine sulfate aqueous solution) at 40°C for 5 minutes. After that, it was dried at 100°C for 30 minutes, and then further heat-cured at 180°C to produce an evaluation substrate.

-In the case of using resin sheets 3, 4, and 5 containing a light-curable resin composition layer- (3') Exposure, development and baking of resin composition layer

The substrate obtained in (2) above was allowed to stand at room temperature for 1 hour. Afterwards, using a mask pattern, 100 mJ/cm ² of ultraviolet rays are exposed from the support in a way that can form circular holes with opening diameters of 60 μm and 500 μm. The exposure is carried out using a pattern forming device ("UX-2240" manufactured by USHIO Electric Co., Ltd.). Then, it was left to stand at room temperature for 30 minutes, and the support was peeled off.

With respect to the obtained substrate, a developing solution (2% by mass sodium hydroxide aqueous solution at 30°C) was sprayed at a spray pressure of 0.2 MPa on the entire surface of the resin composition layer for 40 seconds for development. In addition, in Comparative Example 2 using the resin sheet 4, a 30°C, 1% by mass sodium carbonate aqueous solution was used for the developer.

After development, it was dried at 80°C for 30 minutes, and then baked at 180°C for 90 minutes to obtain an evaluation substrate.

[Preparation of hardened product for evaluation]

The cured product system for evaluation was prepared by the following procedure.

-When using resin sheets 1 and 2 containing a thermosetting resin composition layer-

The resin composition layers of the resin sheets 1 and 2 are made in contact with the release surface of a PET film with a release layer (“PET501010” manufactured by LINTEC Co., Ltd.; hereafter also referred to as “evaluation support”) The layout is laminated using a vacuum laminator (Nichigo-Morton Co., Ltd. "VP160"). The stacking conditions are vacuum for 20 seconds, pressing temperature 80°C, pressing pressure 0.2 MPa, and pressing time 20 seconds.

After peeling the support from the resin sheet from the obtained laminate, the resin composition layer was thermally cured under curing conditions of 180°C for 90 minutes. Next, the support for evaluation was peeled off to obtain a cured product for evaluation.

-In the case of using resin sheets 3, 4, and 5 containing a light-curable resin composition layer-

The resin composition layers of the resin sheets 3, 4, and 5 were implemented in the same manner as the above [Preparation of Cured Product for Evaluation 1], and laminated on a PET film with a release layer (“PET501010” manufactured by LINTEC Co., Ltd.; also called "Evaluation support") release surface.

After the resulting laminate was left at room temperature for 1 hour, the resin composition layer was exposed to ultraviolet light of 100 mJ/cm ² from the support. After peeling the support from the resin sheet, the resin composition layer was treated under baking conditions of 80°C for 30 minutes and then 180°C for 90 minutes. Next, the support for evaluation was peeled off to obtain a cured product for evaluation.

<Evaluation of Warpage>

First, pass the evaluation board through a reflow device (“HAS-6116” manufactured by ANTUM Co., Ltd., Japan) that reproduces the solder reflow temperature with a peak temperature of 260°C (the reflow temperature profile is based on IPC/JEDEC J-STD-020C). Then, using a shadow moiré device ("TherMoire AXP" manufactured by Akrometrix), the underside of the evaluation substrate was heated using a reflow temperature profile based on IPC/JEDEC J-STD-020C (peak temperature of 260°C). The grid line is used to measure the displacement of the 25mm corner of the center of the evaluation substrate.

The difference between the maximum height and the minimum height of the obtained displacement data is "×" if it is 50μm or more in the full temperature range, and "○" if it is less than 50μm.

<Measurement of Elasticity>

The hardened product for evaluation was cut into a dumbbell shape to obtain a test piece. The tensile strength of this test piece was measured using a tensile tester "RTC-1250A" manufactured by ORIENTEC, and the modulus of elasticity at 23°C and 200°C was determined. The measurement is implemented in accordance with JIS K7127.

<Measurement of glass transition point temperature (Tg)>

The cured product for evaluation was cut into test pieces with a width of 5 mm and a length of 15 mm. A thermomechanical analysis device (“TMA-SS6100” manufactured by Seiko Instruments Co., Ltd.) was used for this test piece, and a thermomechanical analysis by the tensile-weight method was performed. Specifically, after the test piece was installed in the aforementioned device, it was continuously measured twice under the measurement conditions of a load of 1 g and a temperature increase rate of 5°C/min. In the second measurement, the glass transition point temperature Tg (°C) was calculated from the point where the slope of the dimensional change signal changed.

The resin sheets 1, 2, 3, 4, and 5 used in the examples and comparative examples were produced in the following process steps.

<Production example 1> Production of resin sheet 1

12 parts of bisphenol A epoxy resin (Mitsubishi Chemical Corporation "jER828EL", epoxy equivalent approximately 185), naphthalene-type epoxy resin (DIC Corporation "HP4032SS", epoxy equivalent approximately 144) 3 Parts, dixylenol type epoxy resin (Mitsubishi Chemical Corporation "YX4000HK", epoxy equivalent approximately 185) 6 parts, biphenyl type epoxy resin (Nippon Kayaku Co., Ltd. "NC3000H", epoxy Equivalent of about 288) 25 parts, 10 parts of phenoxy resin (Mitsubishi Chemical Corporation "YX6954BH30", 30% by mass solid content of a 1:1 solution of MEK and cyclohexanone), dissolved in the solvent naphtha 15 while stirring Heat to dissolve in the portion. After cooling to room temperature, mix 20 parts of a phenol novolac hardener containing a triazine skeleton (LA-7054 made by DIC Co., Ltd., a MEK solution with a hydroxyl equivalent of 125 and a solid content of 60%) and naphthalene Phenolic hardener (Nippon Steel & Sumikin Chemical Co., Ltd. "SN485", hydroxyl equivalent 215, solid content 60% MEK solution) 10 parts, hardening accelerator (4-dimethylaminopyridine (DMAP), solid Divide 5 mass% MEK solution) 0.4 parts, flame retardant (Sanko Co., Ltd. "HCA-HQ", 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10- Phosphophenanthrene-10-oxide, average particle size 2μm) 3 parts, spherical silica (average particle size 1μm, (Average particle size 1μm) surface-treated with aminosilane coupling agent ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.) Stock) Admatechs "SOC4", carbon content per unit surface area 0.47mg/m ² ) 240 parts, uniformly dispersed with a high-speed rotating mixer, to prepare resin paint 1.

For the support, a PET film with a thickness of 38μm ("NS80A" manufactured by Toray Co., Ltd.) was prepared. On the smooth surface of the support, the resin paint 1 was uniformly applied so that the thickness of the resin composition layer after drying was 16 μm, and it was dried at 80 to 120°C (average 100°C) for 3 minutes to produce a resin sheet 1 .

<Production example 2> Production of resin sheet 2

Except for using 30 parts of phenoxy resin (Mitsubishi Chemical Corporation "YX6954BH30", solid content of 30% by mass MEK/cyclohexanone=1/1 solution) instead of phenoxy resin (Mitsubishi Chemical Corporation"YX6954BH30", 30% by mass of MEK/cyclohexanone=1/1 solution) 10 parts, using a ball surface-treated with an aminosilane coupling agent ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.) Silicon oxide (average particle size 0.5μm, "SOC2" manufactured by Admatechs, carbon content per unit surface area of 0.39mg/m ² ) 75 parts instead of aminosilane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd.) "KBM573") surface-treated spherical silica (average particle size 1μm, "SOC4" manufactured by Admatechs, carbon content per unit surface area 0.47mg/m ² ) of 240 parts, and solvent naphtha Except that the usage amount was changed from 15 parts to 10 parts, the rest was implemented in the same manner as in Production Example 1, resin paint 2 was prepared, and resin sheet 2 was produced.

<Production example 3)> Production of resin sheet 3

Mixing 100 parts of dixylenol type epoxy resin (Mitsubishi Chemical Corporation "YX4000HK", epoxy equivalent of 185, 30% by mass of non-volatile content of MEK and cyclohexanone 1:1 solution), the following synthesis example 1 73 parts of synthetic light-curing alkali-soluble resin A, photopolymerization initiator ("OXE-02" manufactured by BASF JAPAN Co., Ltd.), ethyl ketone, 1-[9-ethyl-6-(2-methylbenzene) (Formyl)-9H-carbazol-3-yl]-,1-(0-acetyloxime), 10% by mass non-volatile MEK solution) 18 parts, with aminosilane coupling agent (Shin-Etsu Chemical Spherical silica (average particle size 0.5μm, manufactured by Admatechs, "SOC2" manufactured by Admatechs, carbon content per unit surface area 0.39mg/m ² ) surface-treated by Industrial Co., Ltd. "KBM573") 120 parts, amine 20 parts of spherical silica (average particle size: 0.1μm, "UFP-30" manufactured by Denki Kogyo Co., Ltd.) surface-treated with base silane coupling agent ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.), thinner (Nippon Kayaku Co., Ltd. "DPHA", dipentaerythritol hexaacrylate) 10 parts, hardening accelerator (Shikoku Kasei Co., Ltd. "2P4MZ", 2-phenyl-4-methylimidazole, non-volatile ingredients 2.5% by mass MEK solution) 8.8 parts, rubber particles (“AC3816N” manufactured by GANTSU KASEI Co., Ltd.) 2.4 parts, photosensitizer (“DETX-S” manufactured by Nippon Kasei Co., Ltd., 2, 4-diethyl) 4.4 parts of MEK solution of 10% by mass of non-volatile content of thioxanthone, 4.4 parts of diethylene glycol monoethyl ether acetal, and 10 parts of diethylene glycol monoethyl ether acetal were uniformly dispersed with a high-speed rotating mixer to prepare resin paint 3.

For the support, a PET film ("R310-16B" manufactured by Mitsubishi Plastics Co., Ltd.) with a thickness of 16 μm was prepared. The resin paint 3 was uniformly applied to the support so that the thickness of the resin composition layer after drying was 23 μm, and it was dried at 75° C. to 120° C. (average 100° C.) for 5 minutes to produce a resin sheet 3.

(Synthesis example 1) Synthesis of light-curing alkali-soluble resin A

In a 300 mL separable flask, weigh 25 g of carbitol acetate and 50 g of 3-isocyanato-3,5,5-trimethylcyclohexyl isocyanate (manufactured by EVONIK), and heat at 40°C Stir. In addition, 92.23 g of pentaerythritol triacrylate-containing material ("M306" manufactured by Toagosei Co., Ltd.), 25 g of carbitol acetate, 0.45 g of dibutyltin dilaurate (manufactured by Tokyo Chemical Industry Co., Ltd.), hydrogen 0.4 g of quinone (manufactured by Tokyo Chemical Industry Co., Ltd.) was mixed for 8 minutes with a blender (manufactured by THINKY, "Dakutoren Taro") to obtain a mixed liquid 1. The obtained mixed liquid 1 was dropped into the above-mentioned 300 mL separable flask over 1 hour using a dropping funnel. After that, it was heated and stirred at 40°C for 30 minutes to obtain 193.08 g of a reactant of 3-isocyanato-3,5,5-trimethylcyclohexyl isocyanate and pentaerythritol triacrylate.

On the other hand, in a 500 mL separable flask, weigh 132.26 g of carbitol acetate and 132.26 g of phenol novolac resin ("TD-2090" manufactured by DIC Corporation), and stir at 75°C until it is completely dissolved. . Next, 193.08 g of the above-mentioned reactant was added, and it was heated and stirred at 85° C. with IR until the isocyanate group disappeared. After cooling to 40°C, 3.11 g of ethanol (manufactured by Junsei Chemical Co., Ltd.) was added, followed by stirring for 2 hours or more to obtain a photocurable alkali-soluble resin A (acrylate-modified phenol resin) containing acrylate groups and phenolic hydroxyl groups, 460.71 g. The properties of the obtained photocurable alkali-soluble resin A are as follows.

‧Solvent-soluble product with a solid content of 60% by mass

‧The ratio of acrylate groups is 18%

‧Number average molecular weight (Mn) converted from polystyrene: 4000

‧Hydroxy equivalent: 246

<Production example 4> Production of resin sheet 4

Mixed bixylenol type epoxy resin (Mitsubishi Chemical Co., Ltd. "YX4000HK", epoxy equivalent 185, 30% by mass of non-volatile content of MEK and cyclohexanone 1:1 solution) 80 parts, containing acrylate group Light-curing alkali-soluble resin with carboxyl group ("ZFR-1533H" manufactured by Nippon Kayaku Co., Ltd., bisphenol F epoxy acrylate, diethylene glycol monoethyl ether acetate solution with 68% solid content, Acid value 70mgKOH/g) 147 parts, photopolymerization initiator ("IRGACURE 907" manufactured by BASF JAPAN Co., Ltd.), 2-methyl-[4-(methylthio)phenyl]morpholinyl-1- Acetone) 2.5 parts, spherical silica (average particle size 0.5μm, SOC2 manufactured by Admatechs) surface-treated with aminosilane coupling agent (KBM573 manufactured by Shin-Etsu Chemical Co., Ltd.), per unit The carbon content of the surface area is 0.39mg/m ² ) 80 parts, spherical silica (average particle size 0.1μm, electrochemical industry) surface-treated with aminosilane coupling agent ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.) (Stock) system "UFP-30") 20 parts, thinner (Kyoeisha Chemical Industry Co., Ltd. "DCPA", tricyclodecane dimethanol diacrylate) 10 parts, hardening accelerator (Shikoku Kasei ) Made of "2P4MZ", 2-phenyl-4-methylimidazole, non-volatile content of 2.5% by mass MEK solution) 8.8 parts, rubber particles (GANTSU KASEI Co., Ltd. "AC3816N") 2.4 parts, photosensitizer (Nippon Kayaku Co., Ltd. "DETX-S", 2, 4-diethylthioxanthone, 10% by mass non-volatile MEK solution) 2 parts, diethylene glycol monoethyl ether 3 parts of acetal (organic solvent) were uniformly dispersed with a high-speed rotating mixer to prepare resin paint 4.

For the support, a PET film ("R310-16B" manufactured by Mitsubishi Plastics Co., Ltd.) with a thickness of 16 μm was prepared. The resin lacquer 4 was uniformly coated on the support so that the thickness of the resin composition layer after drying was 23 μm, and the resin composition layer was dried at 75° C. to 120° C. (average 100° C.) for 5 minutes to produce a resin sheet 4.

<Production example 5> Production of resin sheet 5

Except that the resin paint 3 was uniformly applied so that the thickness of the resin composition layer after drying was 8 μm, and it was dried at 75 to 120°C (average 100°C) for 2 minutes, the rest was carried out in the same manner as in Production Example 3. Make a resin sheet 5.

The obtained resin sheets 1 to 5 were combined as shown in Table 1 below to prepare resin sheet groups 1 to 6. In addition, for the resin sheets 1 to 5 used in each resin sheet group, a cured product for evaluation was prepared in accordance with the aforementioned [Preparation of a cured product for evaluation], and the modulus of elasticity and glass transition temperature (Tg) were measured. The results are shown in Table 1.

<Example 1>

Using the resin sheet group 1, an evaluation substrate was obtained in accordance with the above-mentioned [Preparation of Evaluation Substrate]. The evaluation results are shown in Table 2.

<Example 2>

Using the resin sheet group 2, an evaluation substrate was obtained in accordance with the above-mentioned [Preparation of Evaluation Substrate]. The evaluation results are shown in Table 2.

<Example 3>

Using the resin sheet group 1, an evaluation substrate was obtained in accordance with the above-mentioned [Preparation of Evaluation Substrate]. The evaluation results are shown in Table 2.

<Example 4>

Using the resin sheet group 3, a substrate for evaluation was obtained in accordance with the above-mentioned [Preparation of a substrate for evaluation]. The evaluation results are shown in Table 2.

<Comparative Example 1>

Using the resin sheet group 4, the evaluation substrate was obtained in accordance with the above-mentioned [Preparation of Evaluation Substrate]. The evaluation results are shown in Table 2.

<Comparative Example 2>

Using the resin sheet group 5, an evaluation substrate was obtained in accordance with the above-mentioned [Preparation of Evaluation Substrate]. The evaluation results are shown in Table 2.

<Comparative Example 3>

Using the resin sheet group 4, the evaluation substrate was obtained in accordance with the above-mentioned [Preparation of Evaluation Substrate]. The evaluation results are shown in Table 2.

<Comparative Example 4>

Using the resin sheet group 6, the evaluation substrate was obtained in accordance with the above-mentioned [Preparation of Evaluation Substrate]. The evaluation results are shown in Table 2.

Claims (6)

A resin sheet comprising a support and a photocurable resin composition layer for solder resist joined to the support, wherein the thickness of the resin composition layer is 5 μm or more and 120 μm or less, and the cured product of the resin composition layer is The modulus of elasticity at 23°C is from 6GPa to 40GPa. The resin sheet according to claim 1, wherein the resin composition layer contains 60% by mass of an inorganic filler. The resin sheet according to claim 1, wherein the cured product of the resin composition layer has an elastic modulus at 200°C of 0.2 GPa or more and 15 GPa or less. The resin sheet according to claim 1, wherein the resin composition layer contains a photocurable alkali-soluble resin containing a phenolic hydroxyl group and a radically polymerizable unsaturated group. The resin sheet described in claim 1, which is a resin sheet used for printed wiring boards with a thickness of 250 μm or less. The resin sheet described in claim 1 is used for both the first and second main surfaces of the circuit board of the printed wiring board.