JP7494960B1 - Hardened body - Google Patents

Abstract

[Problem] To provide a cured product that can provide an insulating layer with high adhesion to a conductor layer after a highly accelerated life test under a high-temperature and high-humidity environment. [Solution] A cured product of a resin composition containing a thermosetting resin; the cured product has a surface with an arithmetic mean roughness Ra of less than 100 nm; when a layer of the resin composition is cured under conditions of 200°C for 90 minutes to form a cured sample layer, the contact angle of diethylene glycol-mono-n-butyl ether with the surface of the cured sample layer is less than 30°, and the nitrogen atom concentration obtained based on the peak area of the N1s spectrum in X-ray photoelectron spectroscopy analysis of the surface of the cured sample layer is less than 3.8 atomic %. [Selected Figure] Figure 1

Description

The present invention relates to a cured product of a resin composition containing a thermosetting resin and a method for producing the same. The present invention also relates to a circuit board, a semiconductor chip package, and a semiconductor device that contain the cured product; and a resin sheet from which the cured product can be produced.

Circuit boards and semiconductor chip packages are generally provided with an insulating layer. For example, a printed wiring board, which is a type of circuit board, may be provided with an interlayer insulating layer as an insulating layer. Also, for example, a semiconductor chip package may be provided with a rewiring formation layer as an insulating layer. These insulating layers may be formed from a cured body obtained by curing a resin composition (Patent Documents 1 and 2).

WO 2020/130100 JP 2020-193365 A

A conductor layer may be provided on the insulating layer. This conductor layer is generally patterned to form wiring having an appropriate pattern shape. The conductor layer provided on the insulating layer in this way is usually required to have high adhesion to the insulating layer. Therefore, from the perspective of obtaining high adhesion, it has been proposed to form a conductor layer on the insulating layer after performing ultraviolet treatment and silane coupling agent treatment on the insulating layer.

However, conventional methods do not provide sufficient adhesion after highly accelerated life testing (HAST testing, also known as accelerated environmental testing) in high temperature and humidity environments, and further improvements are required.

The present invention was devised in view of the above problems, and aims to provide a cured body that can provide an insulating layer with high adhesion between the conductor layer and the cured body after a highly accelerated life test (HAST test) in a high temperature and high humidity environment; a method for producing the cured body; a circuit board, a semiconductor chip package, and a semiconductor device that include the cured body; and a resin sheet from which the cured body can be produced.

The present inventors have conducted extensive research to solve the above-mentioned problems, and as a result, have found that the above-mentioned problems can be solved by controlling the surface roughness of the surface of the cured body on which a conductor layer is formed within a specific range and by controlling the surface properties of the cured sample layer formed by curing a resin composition as a material of the cured body under specific conditions so as to satisfy specific requirements, thereby completing the present invention.
That is, the present invention includes the following.

[1] A cured product of a resin composition containing a thermosetting resin;
The cured body has a surface with an arithmetic mean roughness Ra of less than 100 nm;
When a test was conducted in which a layer of the resin composition was cured at 200° C. for 90 minutes to form a cured sample layer,
the contact angle of diethylene glycol-mono-n-butyl ether with the surface of the cured sample layer is less than 30°;
A cured body, in which the nitrogen atomic concentration obtained based on the peak area of the N1s spectrum in X-ray photoelectron spectroscopy of the surface of the cured sample layer is less than 3.8 atomic %.
[2] The cured body according to [1], wherein the nitrogen atom concentration obtained based on the peak area of the N1s spectrum in X-ray photoelectron spectroscopy of the surface of the cured sample layer is 0.1 atomic % or more.
[3] The cured product according to [1] or [2], wherein the resin composition contains an inorganic filler.
[4] The cured product according to [3], wherein the amount of the inorganic filler in the resin composition is 40% by mass or more and 90% by mass or less, based on 100% by mass of the non-volatile components of the resin composition.
[5] The cured product according to any one of [1] to [4], wherein the thermosetting resin contains an epoxy resin.
[6] The cured product according to any one of [1] to [5], wherein the thermosetting resin contains a phenolic resin.
[7] The cured product according to any one of [1] to [6], wherein the thermosetting resin contains an active ester resin.
[8] The cured product according to any one of [1] to [7], wherein the thermosetting resin contains a maleimide resin.
[9] The cured product according to any one of [1] to [8], wherein the resin composition contains a curing accelerator.
[10] The cured product according to any one of [1] to [9], wherein the resin composition contains a resin component containing a nitrogen atom.
[11] The cured product according to any one of [1] to [10], for forming a conductor layer on the surface having an arithmetic mean roughness Ra of less than 100 nm.
[12] A circuit board comprising an insulating layer formed from the cured product according to any one of [1] to [11].
[13] A semiconductor chip package comprising the cured product according to any one of [1] to [11] and a semiconductor chip.
[14] A semiconductor device comprising the circuit board according to [12].
[15] A semiconductor device comprising the semiconductor chip package according to [13].
[16] A method for producing the cured product according to any one of [1] to [11], comprising the steps of:
A step of curing a resin composition containing a thermosetting resin to obtain a cured body;
A step of subjecting the cured body to an ultraviolet treatment;
and treating the cured body with a silane coupling agent.
[17] A resin sheet comprising a support and a layer of a resin composition formed on the support;
The resin composition comprises a thermosetting resin;
When a first test is performed in which a layer of the resin composition is cured to form a sample cured body and the surface of the sample cured body facing the support is subjected to an ultraviolet treatment and a silane coupling agent treatment, the arithmetic mean roughness Ra of the surface facing the support is less than 100 nm;
When a second test was performed in which the layer of the resin composition was cured at 200° C. for 90 minutes to form a cured sample layer,
the contact angle of diethylene glycol-mono-n-butyl ether with the support side surface of the cured sample layer is less than 30°;
A resin sheet in which the nitrogen atom concentration obtained based on the peak area of the N1s spectrum in X-ray photoelectron spectroscopy of the support side surface of the cured sample layer is less than 3.8 atomic %.
[18] In the first test, the layer of the resin composition is cured under conditions of 170° C. for 30 minutes;
In the first test, the ultraviolet treatment was performed by irradiating the sample cured body with ultraviolet light having a wavelength of 172 nm for 10 seconds,
In the first test, the silane coupling agent treatment is performed by immersing the sample cured body in an aqueous solution containing 5 g/L of 3-amino-propyltrimethoxysilane and 350 g/L of diethylene glycol-mono-n-butyl ether at 40° C. for 10 minutes. The resin sheet according to [17].

The present invention provides a cured body that can provide an insulating layer with high adhesion between the conductor layer and the cured body after a highly accelerated life test (HAST test) in a high temperature and high humidity environment; a method for producing the cured body; a circuit board, a semiconductor chip package, and a semiconductor device that include the cured body; and a resin sheet from which the cured body can be produced.

FIG. 1 is a cross-sectional view showing a schematic diagram of a fan-out type WLP as an example of a semiconductor chip package according to an embodiment of the present invention.

The present invention will be described in detail below with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples given below, and may be modified as desired without departing from the scope of the claims and their equivalents.

<Overview of the hardened body>
A cured product according to one embodiment of the present invention is a cured product of a resin composition containing a thermosetting resin. This cured product satisfies the following requirements (i) to (iii).
(i) The cured body has a surface with an arithmetic mean roughness Ra of less than 100 nm.
(ii) When a test is conducted in which a layer of the resin composition is cured under conditions of 200° C. for 90 minutes to form a cured sample layer, the contact angle X of diethylene glycol-mono-n-butyl ether with the surface of the cured sample layer is less than 30°.
(iii) When a test is performed in which a layer of the resin composition is cured under conditions of 200° C. for 90 minutes to form a cured sample layer, the nitrogen atom concentration obtained based on the peak area of the N1s spectrum in X-ray photoelectron spectroscopy (XPS) analysis of the surface of the cured sample layer is less than 3.8 atomic %.

A surface of a cured body having an arithmetic mean roughness Ra of less than 100 nm may be referred to as a "specifically smooth surface" below. When a conductor layer is formed on the specific smooth surface of a cured body, high adhesion can be obtained between the conductor layer and the cured body after a highly accelerated life test (HAST test) in a high temperature and high humidity environment. Therefore, with the cured body, an insulating layer with high adhesion to the conductor layer can be obtained after the HAST test.

Without being bound by any particular theory, the inventors speculate that the mechanism by which the above-mentioned effects are obtained is as follows. However, the technical scope of the present invention is not limited by the mechanism described below.

At the time the conductor layer is formed on the specific smooth surface of the cured body, the specific smooth surface is usually in a state where it has been treated with ultraviolet light and a silane coupling agent. The ultraviolet treatment generates functional groups such as -COOH groups on the specific smooth surface of the cured body. Furthermore, the silane coupling agent treatment bonds and fixes the silane coupling agent to the functional groups, improving the affinity of the specific smooth surface for inorganic materials. Generally, inorganic materials such as metals are used as the material for the conductor layer, so when a conductor layer is formed on the specific smooth surface, high adhesion can be obtained between the cured body and the conductor layer.

In the requirement (ii), the surface properties of the cured sample layer are correlated with the properties of the specific smooth surface of the cured body before the ultraviolet treatment and the silane coupling agent treatment. Usually, the surface properties of the cured sample layer are consistent with the properties of the specific smooth surface of the cured body. Also, in the requirement (ii), the contact angle X of diethylene glycol-mono-n-butyl ether with respect to the surface of the cured sample layer is correlated with the affinity of the surface of the cured sample layer with the treatment liquid used for the silane coupling agent treatment. Therefore, when the requirement (ii) is satisfied, usually, the contact angle of the treatment liquid of the silane coupling agent treatment with the specific smooth surface of the cured body is sufficiently small, and therefore, the specific smooth surface of the cured body can have a high affinity for the treatment liquid of the silane coupling agent treatment. Therefore, since the compatibility of the treatment liquid with the specific smooth surface of the cured body can be increased, the bonding between the silane coupling agent and the functional groups on the specific smooth surface can be smoothly promoted, and the degree of the bonding can be highly uniform within the specific smooth surface.

In addition, in the requirement (iii), the nitrogen atom concentration on the surface of the hardened sample layer correlates with the nitrogen atom concentration on the specific smooth surface of the hardened body before the ultraviolet treatment and the silane coupling agent treatment. Usually, the nitrogen atom concentration on the surface of the hardened sample layer coincides with the nitrogen atom concentration on the specific smooth surface of the hardened body. When the nitrogen atom concentration is within the specific range, functional groups such as -COOH groups can be effectively generated by the ultraviolet treatment. In addition, when the requirement (iii) is satisfied, usually, the specific smooth surface of the hardened body can have a high affinity for the treatment liquid of the silane coupling agent treatment, so that the compatibility of the treatment liquid with the specific smooth surface of the hardened body can be increased, as explained in the requirement (ii).

Therefore, when the above requirements (ii) and (iii) are met, a strong adhesion improvement effect can be obtained due to the chemical action obtained by the ultraviolet treatment and the silane coupling agent treatment. Therefore, high adhesion can be obtained between the cured body and the conductor layer after the HAST test.

However, after repeated experiments, the inventors found that in order for the above-mentioned chemical action to be effective, the specific smooth surface of the cured body must be highly smooth. Given the conventional technical common sense that surfaces with low smoothness provide higher adhesion due to the anchor effect, it is surprising that a specific smooth surface with high smoothness provides excellent adhesion after the HAST test.

Generally, ultraviolet light treatment and silane coupling agent treatment do not cause any change in the arithmetic mean roughness Ra of the surface of the cured body. Therefore, the arithmetic mean roughness Ra of the specific smooth surface of the cured body may be measured either before or after the ultraviolet light treatment and silane coupling agent treatment.

For example, a cured body having a specific smooth surface in which the arithmetic mean roughness Ra measured before the ultraviolet treatment and the silane coupling agent treatment is within a specific range that satisfies requirement (i) can obtain high adhesion between the cured body and the conductor layer after the HAST test when a conductor layer is formed on the specific smooth surface after the ultraviolet treatment and the silane coupling agent treatment. Therefore, a cured body having an arithmetic mean roughness Ra on a specific smooth surface that satisfies requirement (i) before the ultraviolet treatment and the silane coupling agent treatment is included in the cured body according to this embodiment.

For example, a cured body having a specific smooth surface in which the arithmetic mean roughness Ra measured after ultraviolet treatment and silane coupling agent treatment is within a specific range that satisfies requirement (i) can obtain high adhesion between the cured body and the conductor layer after a HAST test when a conductor layer is formed on the specific smooth surface. Therefore, a cured body having an arithmetic mean roughness Ra on a specific smooth surface that satisfies requirement (i) after ultraviolet treatment and silane coupling agent treatment is included in the cured body according to this embodiment.

Normally, the cured body can obtain high adhesion between the conductor layer and the cured body not only after the HAST test but also before the HAST test. In addition, it is preferable that the cured body has a low dielectric tangent. In addition, it is preferable that the cured body has a high glass transition temperature.

<Requirement (i). Arithmetic mean roughness Ra of specific smooth surface of hardened body>
The cured body according to the present embodiment has a specific smooth surface having a specific range of arithmetic mean roughness Ra. Specifically, the range of the arithmetic mean roughness Ra of the specific smooth surface is usually less than 100 nm, preferably 80 nm or less, more preferably 60 nm or less, and preferably 10 nm or more, more preferably 20 nm or more, and even more preferably 30 nm or more. When the specific smooth surface of the cured body has an arithmetic mean roughness Ra in the above range, the adhesion between the conductor layer formed on the specific smooth surface and the cured body after the HAST test can be increased, and usually, the adhesion before the HAST test can also be improved.

The arithmetic mean roughness Ra of the specific smooth surface of the cured body can be measured in accordance with the Japanese Industrial Standards (JIS B0601-2001). The measurement can be performed using a non-contact surface roughness meter (WYKO NT3300, manufactured by Beco Instruments). The specific method for measuring the arithmetic mean roughness Ra can be the method described in <Test 4. Measurement of surface roughness Ra and Rz> in the examples below.

The arithmetic mean roughness Ra of the specific smooth surface of the cured body can be adjusted, for example, by the composition of the resin composition. For example, when a resin composition containing an inorganic filler is used, the arithmetic mean roughness Ra can be adjusted by the particle size of the inorganic filler. Also, for example, when a cured body is obtained by curing a resin composition layer (a layer of a resin composition) provided on a resin sheet, the arithmetic mean roughness Ra can be adjusted by the surface roughness of the support provided on the resin sheet and the lamination conditions.

<Requirement (ii). Contact angle X of the surface of the cured sample layer>
The cured product according to the present embodiment is a cured product of a resin composition. When a test was conducted in which a layer of a resin composition (hereinafter sometimes referred to as a "resin composition layer") was formed from the resin composition and the resin composition layer was cured under conditions of 200°C for 90 minutes to form a cured sample layer, the contact angle X of diethylene glycol-mono-n-butyl ether with the surface of the cured sample layer was within a specific range.

The specific range of the contact angle X is usually less than 30°, preferably 28° or less, more preferably 25° or less, particularly preferably 20° or less, and preferably greater than 0°, more preferably 1° or more, even more preferably 3° or more, particularly preferably 6° or more. When the contact angle X is within the above range, the adhesion between the conductor layer formed on the specific smooth surface and the cured body after the HAST test can be increased, and usually, the adhesion before the HAST test can also be improved.

The cured sample layer can be formed by forming a resin composition layer and curing it under the curing conditions of 200°C for 90 minutes. The surface of the cured sample layer thus formed usually has an arithmetic mean roughness Ra within the range specified in the above-mentioned requirement (i). The contact angle X can be measured by the droplet method using the θ/2 method. Specifically, a 1.0 μL droplet of diethylene glycol-mono-n-butyl ether is attached to the surface of the cured sample layer, and the contact angle X can be measured 2000 ms after the droplet is attached. The detailed method for measuring the contact angle X can be the method described in <Test 1. Measurement of contact angle X> in the examples below.

The contact angle X can be adjusted, for example, by the composition of the resin components of the resin composition. Unless otherwise specified, the resin components of the resin composition refer to the non-volatile components contained in the resin composition excluding inorganic fillers. To give a specific example, the contact angle X tends to be large when there is a large amount of non-polar resin such as silicone-based resin. Also, when a polar resin is contained, the contact angle X tends to be small.

The cured sample layer represents a sample to be subjected to a measurement test to identify the attributes of the resin composition (and thus the attributes of the cured body). Requirement (ii) specifies the range of the contact angle X of diethylene glycol-mono-n-butyl ether with the surface of this cured sample layer. Thus, the specific smooth surface of the cured body may or may not have a contact angle X within a specific range.

<Requirement (iii): Nitrogen atom concentration on the surface of the hardened sample layer>
The cured product according to the present embodiment is a cured product of a resin composition as described above. When a test was conducted in which a layer of the resin composition (resin composition layer) was cured under conditions of 200° C. for 90 minutes to form a cured sample layer, the nitrogen atom concentration obtained based on the peak area of the N1s spectrum in X-ray photoelectron spectroscopy of the surface of the cured sample layer was within a specific range.

The specific range of the nitrogen atomic concentration is usually less than 3.8 atomic %, preferably 3.5 atomic % or less, more preferably 3.0 atomic % or less, and preferably 0.1 atomic % or more, more preferably 0.5 atomic % or more, and even more preferably 1.0 atomic % or more. When the nitrogen atomic concentration is within the above range, the adhesion between the conductor layer formed on the specific smooth surface and the cured body after the HAST test can be increased, and usually, the adhesion before the HAST test can also be improved.

The cured sample layer can be formed by forming a resin composition layer as described above and curing it under the curing conditions of 200°C for 90 minutes. The nitrogen atom concentration on the surface of the cured sample layer can be measured using X-ray photoelectron spectroscopy. Specifically, the nitrogen atom concentration can be measured as the ratio of the area of the N1s peak to the area of all peaks in the spectrum measured by X-ray photoelectron spectroscopy. A detailed method for measuring the nitrogen atom concentration by X-ray photoelectron spectroscopy can be the method described in <Test 2. XPS Measurement> in the Examples below.

The nitrogen atom concentration can be adjusted, for example, by the composition of the resin component of the resin composition. As a specific example, the nitrogen atom concentration on the surface of the cured sample layer can be adjusted by adjusting the amount of resin containing nitrogen atoms. However, when the resin composition layer is heated and cured, the resin in the resin composition layer may flow, and the composition of the resin contained in the resin composition layer in the thickness direction may be distributed. For example, even if the resin composition layer has a uniform composition in the thickness direction, the resin may flow during curing, and the resin containing nitrogen atoms may be included so as to be unevenly distributed near the surface of the resin composition layer. The flow may change depending on the curing conditions. Therefore, it is preferable to adjust the composition of the resin composition so that the surface of the cured sample layer obtained by curing under the curing condition of 200 ° C. for 90 minutes, rather than under other curing conditions, has a nitrogen atom concentration in the above range.

As described above, the cured sample layer represents a sample that is subjected to a measurement test to identify the attributes of the resin composition (and thus the attributes of the cured body). Requirement (iii) specifies the range of nitrogen atom concentration obtained based on the peak area of the N1s spectrum in X-ray photoelectron spectroscopy of the surface of this cured sample layer. Therefore, the specific smooth surface of the cured body may or may not have a specific range of nitrogen atom concentration.

<Resin Composition>
The cured body according to the present embodiment is a member obtained by curing the resin composition as described above. The resin composition contains a thermosetting resin (A) as the component (A). As the thermosetting resin (A), a resin that can be cured when heat is applied can be used. As the thermosetting resin (A), one type may be used alone, or two or more types may be used in combination.

((A-1) Epoxy resin)
The thermosetting resin (A) preferably contains an epoxy resin (A-1) as the component (A-1). The epoxy resin (A-1) is a curable resin having an epoxy group. Examples of the epoxy resin (A-1) include bixylenol type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AF type epoxy resins, dicyclopentadiene type epoxy resins, trisphenol type epoxy resins, naphthol novolac type epoxy resins, phenol novolac type epoxy resins, tert-butyl-catechol type epoxy resins, naphthalene type epoxy resins, naphthol type epoxy resins, anthracene type epoxy resins, glycidylamine type epoxy resins, glycidyl ester type epoxy resins, cresol novolac type epoxy resins, phenol aralkyl type epoxy resins, biphenyl type epoxy resins, linear aliphatic epoxy resins, epoxy resins having a butadiene structure, alicyclic epoxy resins, heterocyclic epoxy resins, spiro ring-containing epoxy resins, cyclohexane type epoxy resins, cyclohexane dimethanol type epoxy resins, naphthylene ether type epoxy resins, trimethylol type epoxy resins, tetraphenylethane type epoxy resins, isocyanurate type epoxy resins, and phenolphthalimidine type epoxy resins. The epoxy resin (A-1) may be used alone or in combination of two or more kinds.

From the viewpoint of obtaining a cured product with excellent heat resistance, it is preferable that the (A-1) epoxy resin contains an epoxy resin containing an aromatic structure. An aromatic structure is a chemical structure generally defined as aromatic, and also includes polycyclic aromatic rings and aromatic heterocycles. Examples of epoxy resins containing an aromatic structure include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AF type epoxy resins, dicyclopentadiene type epoxy resins, trisphenol type epoxy resins, naphthol novolac type epoxy resins, phenol novolac type epoxy resins, tert-butyl-catechol type epoxy resins, naphthalene type epoxy resins, naphthol type epoxy resins, anthracene type epoxy resins, bisxylenol type epoxy resins, glycidylamine type epoxy resins having an aromatic structure, glycidyl ester type epoxy resins having an aromatic structure, cresol novolac type epoxy resins, biphenyl type epoxy resins, linear aliphatic epoxy resins having an aromatic structure, epoxy resins having a butadiene structure having an aromatic structure, alicyclic epoxy resins having an aromatic structure, heterocyclic epoxy resins, spiro ring-containing epoxy resins having an aromatic structure, cyclohexane dimethanol type epoxy resins having an aromatic structure, naphthylene ether type epoxy resins, trimethylol type epoxy resins having an aromatic structure, and tetraphenylethane type epoxy resins having an aromatic structure.

From the viewpoint of obtaining a cured product with excellent heat resistance, it is preferable that the (A-1) epoxy resin contains an epoxy resin containing a nitrogen atom. Examples of epoxy resins containing nitrogen atoms include glycidylamine type epoxy resins.

The (A-1) epoxy resin preferably contains an epoxy resin having two or more epoxy groups in one molecule. The proportion of the epoxy resin having two or more epoxy groups in one molecule relative to 100% by mass of the non-volatile components of the (A-1) epoxy resin is preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass or more.

Epoxy resins include epoxy resins that are liquid at a temperature of 20°C (hereinafter sometimes referred to as "liquid epoxy resins") and epoxy resins that are solid at a temperature of 20°C (hereinafter sometimes referred to as "solid epoxy resins"). The epoxy resin (A-1) contained in the resin composition may be only a liquid epoxy resin, only a solid epoxy resin, or a combination of a liquid epoxy resin and a solid epoxy resin.

Preferably, the liquid epoxy resin has two or more epoxy groups in one molecule.

Preferred liquid epoxy resins are bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AF type epoxy resins, naphthalene type epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, phenol novolac type epoxy resins, alicyclic epoxy resins having an ester skeleton, cyclohexane type epoxy resins, cyclohexane dimethanol type epoxy resins, and epoxy resins having a butadiene structure.

Specific examples of liquid epoxy resins include DIC's "HP4032", "HP4032D", and "HP4032SS" (naphthalene type epoxy resins); Mitsubishi Chemical's "828US", "828EL", "jER828EL", "825", and "Epicoat 828EL" (bisphenol A type epoxy resins); Mitsubishi Chemical's "jER807" and "1750" (bisphenol F type epoxy resins); Mitsubishi Chemical's "jER152" (phenol novolac type epoxy resin); Mitsubishi Chemical's "630", "630LSD", "JER630LSD", and "604" (glycidylamine type epoxy resins); ADEKA's "ED-523T" (glycilol type epoxy resin); ADEKA's "EP-3950L" and "EP-3 980S (glycidylamine type epoxy resin); ADEKA's "EP-4088S" (dicyclopentadiene type epoxy resin); Nippon Steel Chemical & Material Chemical's "ZX-1059" (mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin); Nagase Chemtex's "EX-721" (glycidyl ester type epoxy resin); Daicel's "Celloxide 2021P" (alicyclic epoxy resin with ester structure); Daicel's "PB-3600", Nippon Soda's "JP-100" and "JP-200" (epoxy resin with butadiene structure); Nippon Steel Chemical & Material's "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane type epoxy resin). These may be used alone or in combination of two or more types.

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

Preferred solid epoxy resins are bixylenol type epoxy resins, naphthalene type epoxy resins, naphthalene type tetrafunctional epoxy resins, naphthol novolac type epoxy resins, cresol novolac type epoxy resins, dicyclopentadiene type epoxy resins, trisphenol type epoxy resins, naphthol type epoxy resins, biphenyl type epoxy resins, naphthylene ether type epoxy resins, anthracene type epoxy resins, bisphenol A type epoxy resins, bisphenol AF type epoxy resins, phenol aralkyl type epoxy resins, tetraphenylethane type epoxy resins, and phenolphthalimidine type epoxy resins.

Specific examples of solid epoxy resins include DIC's "HP4032H" (naphthalene type epoxy resin); DIC's "HP-4700" and "HP-4710" (naphthalene type tetrafunctional epoxy resin); DIC's "N-690" (cresol novolac type epoxy resin); DIC's "N-695" (cresol novolac type epoxy resin); DIC's "HP-7200", "HP-7200HH", "HP-7200H", and "HP-7200L" (dicyclopentadiene type epoxy resin); DIC's "EXA-7311" and "E XA-7311-G3, EXA-7311-G4, EXA-7311-G4S, HP6000, HP6000L (naphthylene ether type epoxy resin); EPPN-502H (trisphenol type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; NC7000L (naphthol novolac type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; NC3000H, NC3000, NC3000L, NC3000FH, NC3100 (biphenyl type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; ESN475V manufactured by Nippon Steel Chemical & Material Co., Ltd. "ESN4100V" (naphthalene type epoxy resin); "ESN485" (naphthol type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "ESN375" (dihydroxynaphthalene type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YX4000H", "YX4000", "YX4000HK", "YL7890" (bixylenol type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd.; "YL6121" (biphenyl type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd.; "YX8800" (anthracene type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd.; Examples include "YX7700" (phenol aralkyl type epoxy resin); "PG-100" and "CG-500" manufactured by Osaka Gas Chemicals; "YL7760" (bisphenol AF type epoxy resin) manufactured by Mitsubishi Chemical; "YL7800" (fluorene type epoxy resin) manufactured by Mitsubishi Chemical; "jER1010" (bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical; "jER1031S" (tetraphenylethane type epoxy resin) manufactured by Mitsubishi Chemical; and "WHR991S" (phenolphthalimidine type epoxy resin) manufactured by Nippon Kayaku Co., Ltd. These may be used alone or in combination of two or more types.

When a liquid epoxy resin and a solid epoxy resin are used in combination as the epoxy resin, the mass ratio between them (liquid epoxy resin:solid epoxy resin) is preferably in the range of 20:1 to 1:10, more preferably 10:1 to 1:5, and particularly preferably 5:1 to 1:2.

The epoxy equivalent range of the (A-1) epoxy resin is preferably 50 g/eq. to 5,000 g/eq., more preferably 60 g/eq. to 3,000 g/eq., even more preferably 80 g/eq. to 2,000 g/eq., and particularly preferably 90 g/eq. to 1,000 g/eq. The epoxy equivalent represents the mass of the resin per equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K7236.

The weight average molecular weight (Mw) of the epoxy resin (A-1) is preferably in the range of 100 to 5,000, more preferably 250 to 3,000, and even more preferably 400 to 1,500. The weight average molecular weight of the resin can be measured as a polystyrene-equivalent value by gel permeation chromatography (GPC).

The amount of the epoxy resin (A-1) in the resin composition can be set within a range that satisfies the above-mentioned requirements (i) to (iii). In one example, the range of the amount of the epoxy resin (A-1) is preferably 0.1% by mass or more, more preferably 1% by mass or more, and even more preferably 3% by mass or more, and preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 10% by mass or less, based on 100% by mass of the non-volatile components of the resin composition. When the amount of the epoxy resin (A-1) is within the above range, the adhesion between the conductor layer formed on the specific smooth surface and the cured body after the HAST test can be particularly high. In addition, it is usually possible to effectively improve the adhesion before the HAST test, and to improve the dielectric tangent, storage modulus, glass transition temperature, and crosslink density of the cured body.

In one example, the range of the amount of the epoxy resin (A-1) in the resin composition is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, and is preferably 80% by mass or less, more preferably 60% by mass or less, and even more preferably 50% by mass or less, based on 100% by mass of the resin components of the resin composition. As described above, the resin components of the resin composition refer to the non-volatile components contained in the resin composition excluding the inorganic filler. When the amount of the epoxy resin (A-1) is within the above range, the adhesion after the HAST test between the conductor layer formed on the specific smooth surface and the cured body can be particularly high. In addition, it is usually possible to effectively improve the adhesion before the HAST test, and to improve the dielectric tangent, storage modulus, glass transition temperature, and crosslink density of the cured body.

((A-2) Phenolic resin)
The thermosetting resin (A) preferably contains a phenolic resin (A-2) as the component (A-2). As the phenolic resin (A-2), a compound having at least one, preferably at least two, phenolic hydroxyl groups in one molecule can be used. The phenolic hydroxyl group refers to a hydroxyl group bonded to an aromatic ring such as a benzene ring or a naphthalene ring. In particular, the phenolic resin (A-2) is preferably used in combination with the epoxy resin (A-1). When the epoxy resin (A-1) and the phenolic resin (A-2) are used in combination, the phenolic resin (A-2) reacts with the epoxy resin (A-1) to form a bond and can function as a curing agent that cures the resin composition.

From the viewpoint of heat resistance and water resistance, the phenolic resin (A-2) is preferably a phenolic resin having a novolac structure. From the viewpoint of adhesion, a nitrogen-containing phenolic resin is preferable, and a triazine skeleton-containing phenolic resin is more preferable. Among them, from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion, a triazine skeleton-containing phenolic novolac resin is preferable.

Specific examples of (A-2) phenolic resins include, for example, "MEH-7700", "MEH-7810", "MEH-7851", and "MEH-8000" manufactured by Meiwa Kasei Co., Ltd., "NHN", "CBN", and "GPH" manufactured by Nippon Kayaku Co., Ltd., "SN-170", "SN-180", "SN-190", "SN-475", "SN-485", "SN-495", "SN-375", and "SN-395" manufactured by Nippon Steel Chemical & Material Co., Ltd., and DIC Examples include "TD-2090", "LA-7052", "LA-7054", "LA-1356", "LA-3018", "LA-3018-50P", "LA-1356", "TD2090", "TD-2090-60M", "EXB-9500", "HPC-9500", "KA-1160", "KA-1163", and "KA-1165" manufactured by Gunei Chemical Co., Ltd., and "GDP-6115L" and "GDP-6115H" manufactured by Gunei Chemical Co., Ltd.

(A-2) The phenolic resin may be used alone or in combination of two or more types.

The hydroxyl equivalent range of the (A-2) phenolic resin is preferably 50 g/eq. to 3000 g/eq., more preferably 100 g/eq. to 1000 g/eq., even more preferably 100 g/eq. to 500 g/eq., and particularly preferably 100 g/eq. to 300 g/eq. The hydroxyl equivalent represents the mass of the resin per equivalent of hydroxyl groups.

The weight average molecular weight range of the (A-2) phenolic resin may be the same as the weight average molecular weight range of the (A-1) epoxy resin.

When the number of epoxy groups in the (A-1) epoxy resin is taken as 1, the range of the number of hydroxyl groups in the (A-2) phenolic resin is preferably 0.01 or more, more preferably 0.10 or more, even more preferably 0.15 or more, and preferably 5.0 or less, more preferably 2.0 or less, and particularly preferably 1.0 or less. The "number of epoxy groups in the (A-1) epoxy resin" refers to the total value obtained by dividing the mass of the non-volatile components of the epoxy resin present in the resin composition by the epoxy equivalent. The "number of hydroxyl groups in the (A-2) phenolic resin" refers to the total value obtained by dividing the mass of the non-volatile components of the phenolic resin present in the resin composition by the hydroxyl equivalent.

The amount of (A-2) phenolic resin in the resin composition can be set within a range that satisfies the above-mentioned requirements (i) to (iii). In one example, the range of the amount of (A-2) phenolic resin is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.5% by mass or more, and is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less, based on 100% by mass of the non-volatile components of the resin composition. When the amount of (A-2) phenolic resin is within the above range, the adhesion between the conductor layer formed on the specific smooth surface and the cured body after the HAST test can be particularly high. In addition, it is usually possible to effectively improve the adhesion before the HAST test, and to improve the dielectric tangent, storage modulus, glass transition temperature, and crosslink density of the cured body.

In one example, the range of the amount of (A-2) phenolic resin in the resin composition is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more, relative to 100% by mass of the resin components of the resin composition, and is preferably 60% by mass or less, more preferably 50% by mass or less, and even more preferably 40% by mass or less. When the amount of (A-2) phenolic resin is within the above range, the adhesion after the HAST test between the conductor layer formed on the specific smooth surface and the cured body can be particularly high. Also, it is usually possible to effectively improve the adhesion before the HAST test, and to improve the dielectric tangent, storage modulus, glass transition temperature, and crosslink density of the cured body.

((A-3) Active Ester Resin)
The thermosetting resin (A) preferably contains an active ester resin (A-3) as the component (A-3). As the active ester resin (A-3), a compound having two or more highly reactive ester groups in one molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds, is preferably used. In particular, the active ester resin (A-3) is preferably used in combination with the epoxy resin (A-1). When the epoxy resin (A-1) and the active ester resin (A-3) are used in combination, the active ester resin (A-3) reacts with the epoxy resin (A-1) to form a bond and can function as a curing agent that cures the resin composition.

(A-3) The active ester resin is preferably one obtained by a condensation reaction between a carboxylic acid compound and/or a thiocarboxylic acid compound and a hydroxy compound and/or a thiol compound. In particular, from the viewpoint of improving heat resistance, an active ester resin obtained from a carboxylic acid compound and a hydroxy compound is preferred, and an active ester resin obtained from a carboxylic acid compound and a phenol compound and/or a naphthol compound is more preferred. Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid. Examples of phenol compounds or naphthol compounds include hydroquinone, resorcin, bisphenol A, bisphenol F, bisphenol S, phenolphthaline, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadiene-type diphenol compounds, and phenol novolak. Here, "dicyclopentadiene-type diphenol compounds" refer to diphenol compounds obtained by condensing one molecule of dicyclopentadiene with two molecules of phenol.

Specifically, the active ester resin (A-3) is preferably a dicyclopentadiene type active ester resin, a naphthalene type active ester resin containing a naphthalene structure, an active ester resin containing an acetylated product of phenol novolac, or an active ester resin containing a benzoylated product of phenol novolac, and among these, at least one selected from a dicyclopentadiene type active ester resin and a naphthalene type active ester resin is more preferable. As the dicyclopentadiene type active ester resin, an active ester resin containing a dicyclopentadiene type diphenol structure is preferable.

(A-3) Commercially available active ester resins include, for example, active ester resins containing a dicyclopentadiene-type diphenol structure such as "EXB9451", "EXB9460", "EXB9460S", "EXB-8000L", "EXB-8000L-65M", "EXB-8000L-65TM", "HPC-8000L-65TM", "HPC-8000", "HPC-8000-65T", "HPC-8000H", and "HPC-8000H-65TM" (manufactured by DIC Corporation); active ester resins containing a naphthalene structure such as "HP-B-8151-62T", "EXB-8100L-65T", "EXB-8150-60T", and "EXB-8 Examples of such active ester resins include "EXB9401" (manufactured by DIC Corporation), which is a phosphorus-containing active ester resin; "DC808" (manufactured by Mitsubishi Chemical Corporation), which is an active ester resin that is an acetylated product of phenol novolac; "YLH1026", "YLH1030", and "YLH1048" (manufactured by Mitsubishi Chemical Corporation), which are active ester resins that are benzoylated products of phenol novolac; and "PC1300-02-65MA" (manufactured by Air Water Inc.), which is an active ester resin that contains a styryl group and a naphthalene structure.

(A-3) The active ester resin may be used alone or in combination of two or more types.

The range of the active ester group equivalent of the (A-3) active ester resin is preferably 50 g/eq. to 3000 g/eq., more preferably 100 g/eq. to 1000 g/eq., even more preferably 100 g/eq. to 500 g/eq., and particularly preferably 100 g/eq. to 300 g/eq. The active ester group equivalent represents the mass of the resin per equivalent of active ester groups.

The weight average molecular weight range of the (A-3) active ester resin can be the same as the weight average molecular weight range of the (A-1) epoxy resin.

When the number of epoxy groups in the epoxy resin (A-1) is taken as 1, the range of the number of active ester groups in the active ester resin (A-3) is preferably 0.01 or more, more preferably 0.05 or more, even more preferably 0.10 or more, and preferably 5.0 or less, more preferably 2.0 or less, and particularly preferably 1.0 or less. The "number of active ester groups in the active ester resin (A-3)" refers to the total value obtained by dividing the mass of the non-volatile components of the active ester resin present in the resin composition by the active ester group equivalent.

The amount of the (A-3) active ester resin in the resin composition can be set within a range that satisfies the above-mentioned requirements (i) to (iii). In one example, the range of the amount of the (A-3) active ester resin is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.5% by mass or more, and is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 2% by mass or less, based on 100% by mass of the non-volatile components of the resin composition. When the amount of the (A-3) active ester resin is within the above range, the adhesion between the conductor layer formed on the specific smooth surface and the cured body after the HAST test can be particularly high. In addition, it is usually possible to effectively improve the adhesion before the HAST test, and to improve the dielectric tangent, storage modulus, glass transition temperature, and crosslink density of the cured body.

In one example, the range of the amount of the active ester resin (A-3) in the resin composition is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more, relative to 100% by mass of the resin components of the resin composition, and is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less. When the amount of the active ester resin (A-3) is within the above range, the adhesion between the conductor layer formed on the specific smooth surface and the cured body after the HAST test can be particularly high. Also, it is usually possible to effectively improve the adhesion before the HAST test, and to improve the dielectric tangent, storage modulus, glass transition temperature, and crosslink density of the cured body.

((A-4) Maleimide resin)
The thermosetting resin (A) preferably contains a maleimide resin (A-4) as the component (A-4). As the maleimide resin, a compound containing at least one, preferably two or more maleimide groups (2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl groups) in one molecule can be used. The maleimide resin (A-4) can form bonds by radical polymerization of the ethylenic double bonds contained in the maleimide groups, thereby thermosetting the resin composition. In addition, the maleimide resin (A-4) can function as a curing agent that reacts with the epoxy resin (A-1) to form bonds and cure the resin composition in the presence of a suitable catalyst such as an imidazole compound.

As the (A-4) maleimide resin, an aliphatic maleimide resin containing an aliphatic amine skeleton may be used, an aromatic maleimide resin containing an aromatic amine skeleton may be used, or a combination of these may be used. In addition, the (A-4) maleimide resin may be used alone or in combination of two or more types.

(A-4) Examples of maleimide resins include (1) maleimide resins having an aliphatic skeleton (preferably dimer diamine-derived maleimide having 36 carbon atoms), such as "BMI-3000", "BMI-3000J", "BMI-5000", "BMI-1400", "BMI-1500", "BMI-1700", and "BMI-689" (all manufactured by DigiCner Molecules), and "SLK-6895-T90" (manufactured by Shin-Etsu Chemical Co., Ltd.). (2) Maleimide resins containing an indane skeleton, as described in the Japan Institute of Invention and Innovation's Technical Journal Publication No. 2020-500211; (3) Maleimide resins containing an aromatic ring skeleton directly bonded to the nitrogen atom of the maleimide group, such as "MIR-3000-70MT" (manufactured by Nippon Kayaku Co., Ltd.), "BMI-4000" (manufactured by Daiwa Kasei Co., Ltd.), and "BMI-80" (manufactured by Keiai Kasei Co., Ltd.).

(A-4) The maleimide resin may be used alone or in combination of two or more types.

The range of the maleimide group equivalent of (A-4) maleimide resin is preferably 50 g/eq. to 3000 g/eq., more preferably 100 g/eq. to 1000 g/eq., and even more preferably 100 g/eq. to 500 g/eq. The maleimide group equivalent represents the mass of the resin per equivalent of maleimide group.

The weight average molecular weight range of the maleimide resin (A-4) can be the same as the weight average molecular weight range of the epoxy resin (A-1).

When the number of epoxy groups in the epoxy resin (A-1) is taken as 1, the range of the number of maleimide groups in the maleimide resin (A-4) is preferably 0.01 or more, more preferably 0.05 or more, even more preferably 0.10 or more, and preferably 5.0 or less, more preferably 2.0 or less, and particularly preferably 1.0 or less. The "number of maleimide groups in the maleimide resin (A-4)" refers to the total value obtained by dividing the mass of the non-volatile components of the maleimide resin present in the resin composition by the active ester group equivalent.

The amount of (A-4) maleimide resin in the resin composition can be set within a range that satisfies the above-mentioned requirements (i) to (iii). In one example, the range of the amount of (A-4) maleimide resin is preferably 0.1% by mass or more, more preferably 1.0% by mass or more, and even more preferably 2.0% by mass or more, and is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less, based on 100% by mass of the non-volatile components of the resin composition. When the amount of (A-4) maleimide resin is within the above range, the adhesion between the conductor layer formed on the specific smooth surface and the cured body after the HAST test can be particularly high. In addition, it is usually possible to effectively improve the adhesion before the HAST test, and to improve the dielectric tangent, storage modulus, glass transition temperature, and crosslink density of the cured body.

In one example, the range of the amount of the maleimide resin (A-4) in the resin composition is preferably 1% by mass or more, more preferably 4% by mass or more, and even more preferably 6% by mass or more, relative to 100% by mass of the resin components of the resin composition, and is preferably 70% by mass or less, more preferably 60% by mass or less, and even more preferably 50% by mass or less. When the amount of the maleimide resin (A-4) is within the above range, the adhesion between the conductor layer formed on the specific smooth surface and the cured body after the HAST test can be particularly high. Also, it is usually possible to effectively improve the adhesion before the HAST test, and to improve the dielectric tangent, storage modulus, glass transition temperature, and crosslink density of the cured body.

(any thermosetting resin)
Other examples of the (A) thermosetting resin include cyanate ester resins, carbodiimide resins, acid anhydride resins, amine resins, benzoxazine resins, and thiol resins. When these resins are used in combination with the (A-1) epoxy resin, they can function as a curing agent that reacts with the (A-1) epoxy resin to form a bond and cure the resin composition. The curing agent may be used alone or in combination of two or more types.

When the (A) thermosetting resin contains a combination of the (A-1) epoxy resin and a curing agent, it is preferable that the amount of the curing agent, such as the (A-2) phenolic resin, (A-3) active ester resin, cyanate ester resin, carbodiimide resin, acid anhydride resin, amine resin, benzoxazine resin, or thiol resin, falls within a specific range. Here, in a system in which the (A-1) epoxy resin and the (A-4) maleimide resin can react and bond, the (A-4) maleimide resin is also included in the curing agent. The specific range of the amount of the curing agent is preferably 0.1% by mass or more, more preferably 1% by mass or more, and even more preferably 3% by mass or more, and preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less, based on 100% by mass of the non-volatile components of the resin composition. When the amount of the curing agent is within the above range, the adhesion after the HAST test between the conductor layer formed on the specific smooth surface and the cured body can be particularly high. In addition, it usually effectively improves adhesion before HAST testing, and improves the dielectric tangent, storage modulus, glass transition temperature, and crosslink density of the cured material.

The range of the amount of the curing agent is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, relative to 100% by mass of the resin component of the resin composition, and is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less. When the amount of the curing agent is within the above range, the adhesion between the conductor layer formed on the specific smooth surface and the cured body after the HAST test can be particularly high. In addition, it is usually possible to effectively improve the adhesion before the HAST test, and to improve the dielectric tangent, storage modulus, glass transition temperature, and crosslink density of the cured body.

Furthermore, when the number of epoxy groups in the epoxy resin (A-1) is taken as 1, the range of the number of active groups in the curing agent is preferably 0.01 or more, more preferably 0.1 or more, even more preferably 0.3 or more, and preferably 5.0 or less, more preferably 2.0 or less, and particularly preferably 1.0 or less. The "number of active groups in the curing agent" refers to the total value obtained by dividing the mass of the non-volatile components of the curing agent present in the resin composition by the active group equivalent. The active group equivalent of the curing agent refers to the mass of resin per equivalent of an active group such as a phenolic hydroxyl group, an active ester group, or a maleimide group.

Further examples of the (A) thermosetting resin include (A-4) radical polymerizable resins other than maleimide resins. These radical polymerizable resins generally have ethylenically unsaturated bonds and can be cured by radical polymerization. Examples of the radical polymerizable resin include styrene-based radical polymerizable resins having one or more vinyl groups directly bonded to aromatic carbon atoms, and allyl-based radical polymerizable resins having one or more allyl groups. The radical polymerizable resins may be used alone or in combination of two or more types.

The range of weight average molecular weight of the (A) thermosetting resin may be the same as the range of weight average molecular weight of the (A-1) epoxy resin.

(Amount of thermosetting resin containing nitrogen atoms)
A part or all of the thermosetting resin (A) may contain a nitrogen atom. Examples of the thermosetting resin containing a nitrogen atom include (A-4) maleimide resin and amine resin; and (A-1) epoxy resin, (A-2) phenol resin, and (A-3) active ester resin, which contain a nitrogen atom. The thermosetting resin containing a nitrogen atom may be used alone or in combination of two or more kinds.

The amount of the thermosetting resin containing nitrogen atoms in the resin composition can be set within a range that satisfies the above-mentioned requirements (i) to (iii). In one example, the range of the amount of the thermosetting resin containing nitrogen atoms in the resin composition is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more, and preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less, based on 100% by mass of the total amount of the thermosetting resin (A). When the amount of the thermosetting resin containing nitrogen atoms is within the above range, the adhesion between the conductor layer formed on the specific smooth surface and the cured body after the HAST test can be particularly high. In addition, it is usually possible to effectively improve the adhesion before the HAST test, and to improve the dielectric tangent, storage modulus, glass transition temperature, and crosslink density of the cured body.

The range of the amount of the thermosetting resin containing nitrogen atoms in the resin composition is preferably 0.1% by mass or more, more preferably 1% by mass or more, and even more preferably 2% by mass or more, based on 100% by mass of the non-volatile components of the resin composition, and is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less. When the amount of the thermosetting resin containing nitrogen atoms is within the above range, the adhesion between the conductor layer formed on the specific smooth surface and the cured body after the HAST test can be particularly high. In addition, it is usually possible to effectively improve the adhesion before the HAST test, and to improve the dielectric tangent, storage modulus, glass transition temperature, and crosslink density of the cured body.

Furthermore, the range of the amount of the thermosetting resin containing nitrogen atoms in the resin composition is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, and preferably 90% by mass or less, more preferably 80% by mass or less, even more preferably 70% by mass or less, based on 100% by mass of the resin component of the resin composition. When the amount of the thermosetting resin containing nitrogen atoms is within the above range, the adhesion between the conductor layer formed on the specific smooth surface and the cured body after the HAST test can be particularly high. In addition, it is usually possible to effectively improve the adhesion before the HAST test, and to improve the dielectric tangent, storage modulus, glass transition temperature, and crosslink density of the cured body.

(Amount of Thermosetting Resin)
The amount of the (A) thermosetting resin in the resin composition can be set within a range that satisfies the above-mentioned requirements (i) to (iii). In one example, the range of the amount of the (A) thermosetting resin in the resin composition is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 5% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less, based on 100% by mass of the non-volatile components of the resin composition. When the amount of the (A) thermosetting resin is within the above range, the adhesion between the conductor layer formed on the specific smooth surface and the cured body after the HAST test can be particularly high. In addition, usually, the adhesion before the HAST test can be effectively improved, and the dielectric tangent, storage modulus, glass transition temperature, and crosslink density of the cured body can be improved.

The amount of the thermosetting resin (A) is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more, and preferably 100% by mass or less, based on 100% by mass of the resin component of the resin composition. When the amount of the thermosetting resin (A) is within the above range, the adhesion between the conductor layer formed on the specific smooth surface and the cured body after the HAST test can be particularly high. In addition, it is usually possible to effectively improve the adhesion before the HAST test, and to improve the dielectric tangent, storage modulus, glass transition temperature, and crosslink density of the cured body.

((B) Inorganic Filler)
The resin composition may further contain an inorganic filler (B) as an optional component. The inorganic filler (B) as component (B) is usually contained in the resin composition and the cured product in the form of particles.

(B) As the material of the inorganic filler, an inorganic compound is usually used. (B) As the material of the inorganic filler, for example, silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate can be mentioned. Among these, silica and alumina are suitable, and silica is particularly suitable. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. In addition, as the silica, spherical silica is preferable. (B) The inorganic filler may be used alone or in combination of two or more types.

(B) Commercially available inorganic fillers include, for example, "SP60-05" and "SP507-05" manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YC100C", "YA050C", "YA050C-MJE", "YA010C", "SC2500SQ", "SO-C4", "SO-C2", and "SO-C1" manufactured by Admatechs Co., Ltd.; "UFP-30", "DAW-03", and "FB-105FD" manufactured by Denka Co., Ltd.; "Silfil NSS-3N", "Silfil NSS-4N", and "Silfil NSS-5N" manufactured by Tokuyama Corporation; "Cellfiers" and "MGH-005" manufactured by Taiheiyo Cement Corporation; and "Sfereek" and "BA-1" manufactured by JGC Catalysts and Chemicals Co., Ltd.

The range of the average particle size of the inorganic filler (B) is preferably 0.01 μm or more, more preferably 0.05 μm or more, and particularly preferably 0.1 μm or more, from the viewpoint of significantly obtaining the desired effects of the present invention, and is preferably 10 μm or less, more preferably 7 μm or less, and even more preferably 5 μm or less.

(B) The average particle size of the inorganic filler can be measured by a laser diffraction/scattering method based on the Mie scattering theory. Specifically, a particle size distribution of the inorganic filler is created on a volume basis using a laser diffraction/scattering particle size distribution measuring device, and the median diameter is used as the average particle size. The measurement sample can be prepared by weighing 100 mg of inorganic filler and 10 g of methyl ethyl ketone into a vial and dispersing the mixture by ultrasonic waves for 10 minutes. The measurement sample is measured using a laser diffraction particle size distribution measuring device with blue and red light source wavelengths, and the volume-based particle size distribution of the inorganic filler is measured using a flow cell method, and the average particle size can be calculated as the median diameter from the particle size distribution obtained. An example of a laser diffraction particle size distribution measuring device is the "LA-960" manufactured by Horiba, Ltd.

From the viewpoint of significantly obtaining the desired effects of the present invention, the range of the specific surface area of the (B) inorganic filler is preferably 1 m ² /g or more, more preferably 2 m ² /g or more, and particularly preferably 3 m ² /g or more. There is no particular upper limit, but it is preferably 60 m ² /g or less, 50 m ² /g or less, or 40 m ² /g or less. The specific surface area can be measured according to the BET method by adsorbing nitrogen gas onto the surface of a sample using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech Co., Ltd.) and calculating the specific surface area using the BET multipoint method.

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

Examples of commercially available surface treatment agents include Shin-Etsu Chemical's "KBM403" (3-glycidoxypropyltrimethoxysilane), Shin-Etsu Chemical's "KBM803" (3-mercaptopropyltrimethoxysilane), Shin-Etsu Chemical's "KBE903" (3-aminopropyltriethoxysilane), Shin-Etsu Chemical's "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane), Shin-Etsu Chemical's "SZ-31" (hexamethyldisilazane), Shin-Etsu Chemical's "KBM103" (phenyltrimethoxysilane), Shin-Etsu Chemical's "KBM-4803" (long-chain epoxy-type silane coupling agent), and Shin-Etsu Chemical's "KBM-7103" (3,3,3-trifluoropropyltrimethoxysilane).

From the viewpoint of improving the dispersibility of the inorganic filler (B), it is preferable that the degree of surface treatment with the surface treatment agent falls within a specific range. Specifically, it is preferable that 100% by mass of the inorganic filler is surface-treated with 0.2% to 5% by mass of the surface treatment agent, more preferably with 0.2% to 3% by mass of the surface treatment agent, and even more preferably with 0.3% to 2% by mass of the surface treatment agent.

The degree of surface treatment by the surface treatment agent can be evaluated by the amount of carbon per unit surface area of the inorganic filler. From the viewpoint of improving the dispersibility of the inorganic filler, the amount of carbon per unit surface area of the inorganic filler is preferably 0.02 mg/m ² or more, more preferably 0.1 mg/m ² or more, and even more preferably 0.2 mg/m ² or more. On the other hand, from the viewpoint of suppressing an increase in the melt viscosity of the resin composition, it is preferably 1.0 mg/m ² or less, more preferably 0.8 mg/m ² or less, and even more preferably 0.5 mg/m ² or less.

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

The amount of (B) inorganic filler in the resin composition can be set within a range that satisfies the above-mentioned requirements (i) to (iii). In one example, the range of the amount of (B) inorganic filler in the resin composition is preferably 40% by mass or more, more preferably 50% by mass or more, and even more preferably 60% by mass or more, and preferably 90% by mass or less, more preferably 86% by mass or less, and even more preferably 83% by mass or less, based on 100% by mass of the non-volatile components of the resin composition. When the amount of (B) inorganic filler is within the above range, the adhesion between the conductor layer formed on the specific smooth surface and the cured body after the HAST test can be particularly high. In addition, it is usually possible to effectively improve the adhesion before the HAST test, and to improve the dielectric tangent, storage modulus, glass transition temperature, and crosslink density of the cured body.

((C) Curing Accelerator)
The resin composition may further contain a curing accelerator (C) as an optional component. The curing accelerator (C) as the component (C) does not include those corresponding to the above-mentioned components (A) and (B). The curing accelerator (C) functions as a curing catalyst that accelerates the curing of the epoxy resin (A-1).

(C) Examples of the curing accelerator include phosphorus-based curing accelerators, urea-based curing accelerators, guanidine-based curing accelerators, imidazole-based curing accelerators, metal-based curing accelerators, and amine-based curing accelerators. Among these, imidazole-based curing accelerators are preferred. (C) Curing accelerators may be used alone or in combination of two or more types.

Examples of phosphorus-based curing accelerators include aliphatic phosphonium salts such as tetrabutylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium acetate, tetrabutylphosphonium decanoate, tetrabutylphosphonium laurate, bis(tetrabutylphosphonium)pyromellitate, tetrabutylphosphonium hydrogenhexahydrophthalate, tetrabutylphosphonium 2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-methylphenolate, and di-tert-butyldimethylphosphonium tetraphenylborate; methyltriphenylphosphonium bromide, ethyltriphenylphosphonium bromide, propyltriphenylphosphonium bromide, butyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, tetraphenylphosphine aromatic phosphonium salts such as sulfonium bromide, p-tolyltriphenylphosphonium tetra-p-tolylborate, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra-p-tolylborate, triphenylethylphosphonium tetraphenylborate, tris(3-methylphenyl)ethylphosphonium tetraphenylborate, tris(2-methoxyphenyl)ethylphosphonium tetraphenylborate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, and butyltriphenylphosphonium thiocyanate; aromatic phosphine-borane complexes such as triphenylphosphine-triphenylborane; aromatic phosphine-quinone addition products such as triphenylphosphine-p-benzoquinone addition products; tributylphosphine, tri-t Aliphatic phosphines such as tert-butylphosphine, trioctylphosphine, di-tert-butyl(2-butenyl)phosphine, di-tert-butyl(3-methyl-2-butenyl)phosphine, and tricyclohexylphosphine; dibutylphenylphosphine, di-tert-butylphenylphosphine, methyldiphenylphosphine, ethyldiphenylphosphine, butyldiphenylphosphine, diphenylcyclohexylphosphine, triphenylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, tris(4-ethylphenyl)phosphine, tris(4-propylphenyl)phosphine, tris(4-isopropylphenyl)phosphine, tris(4-butylphenyl)phosphine, tris(4-tert-butylphenyl)phosphine, tris(2,4-dimethylphenyl)phosphine, ) phosphine, tris(2,5-dimethylphenyl)phosphine, tris(2,6-dimethylphenyl)phosphine, tris(3,5-dimethylphenyl)phosphine, tris(2,4,6-trimethylphenyl)phosphine, tris(2,6-dimethyl-4-ethoxyphenyl)phosphine, tris(2-methoxyphenyl)phosphine, tris(4-methoxyphenyl)phosphine, tris(4-ethoxyphenyl)phosphine, tris(4-tert-butoxyphenyl)phosphine, diphenyl-2-pyridylphosphine, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 1,4-bis(diphenylphosphino)butane, 1,2-bis(diphenylphosphino)acetylene, 2,2'-bis(diphenylphosphino)diphenyl ether and other aromatic phosphines.

Examples of urea-based hardening accelerators include 1,1-dimethylurea; aliphatic dimethylureas such as 1,1,3-trimethylurea, 3-ethyl-1,1-dimethylurea, 3-cyclohexyl-1,1-dimethylurea, and 3-cyclooctyl-1,1-dimethylurea; 3-phenyl-1,1-dimethylurea, 3-(4-chlorophenyl)-1,1-dimethylurea, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, 3-(3-chloro-4-methylphenyl)-1,1-dimethylurea, 3-(2-methylphenyl)-1,1-dimethylurea, 3-(4-methylphenyl)-1,1-dimethylurea, and 3-(3,4-dimethylphenyl)-1,1-dimethylurea. aromatic dimethylureas such as 3-(4-isopropylphenyl)-1,1-dimethylurea, 3-(4-methoxyphenyl)-1,1-dimethylurea, 3-(4-nitrophenyl)-1,1-dimethylurea, 3-[4-(4-methoxyphenoxy)phenyl]-1,1-dimethylurea, 3-[4-(4-chlorophenoxy)phenyl]-1,1-dimethylurea, 3-[3-(trifluoromethyl)phenyl]-1,1-dimethylurea, N,N-(1,4-phenylene)bis(N',N'-dimethylurea), N,N-(4-methyl-1,3-phenylene)bis(N',N'-dimethylurea) [toluene bisdimethylurea], etc.

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

Examples of imidazole-based curing accelerators include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2- Phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl -(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct , 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, 2-phenylimidazoline, and other imidazole compounds and adducts of imidazole compounds and epoxy resins. Commercially available imidazole curing accelerators include, for example, "1B2PZ", "2E4MZ", "2MZA-PW", "2MZ-OK", "2MA-OK", "2MA-OK-PW", "2PHZ", "2PHZ-PW", "Cl1Z", "Cl1Z-CN", "Cl1Z-CNS", and "C11Z-A" manufactured by Shikoku Chemical Industry Co., Ltd.; and "P200-H50" manufactured by Mitsubishi Chemical Corporation.

Metal-based curing accelerators include, for example, organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organometallic complexes include organocobalt complexes such as cobalt (II) acetylacetonate and cobalt (III) acetylacetonate, organocopper complexes such as copper (II) acetylacetonate, organozinc complexes such as zinc (II) acetylacetonate, organoiron complexes such as iron (III) acetylacetonate, organonickel complexes such as nickel (II) acetylacetonate, and organomanganese complexes such as manganese (II) acetylacetonate. Organometallic salts include, for example, zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

Examples of amine-based curing accelerators include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)-undecene. Commercially available amine-based curing accelerators may be used, such as "MY-25" manufactured by Ajinomoto Fine-Techno Co., Ltd.

The amount of the (C) curing accelerator in the resin composition can be set within a range that satisfies the above-mentioned requirements (i) to (iii). In one example, the range of the amount of the (C) curing accelerator in the resin composition may be 0% by mass or more than 0% by mass, and is preferably 0.0001% by mass or more, more preferably 0.001% by mass or more, even more preferably 0.002% by mass or more, and is preferably 2% by mass or less, more preferably 1% by mass or less, and even more preferably 0.1% by mass or less, based on 100% by mass of the non-volatile components of the resin composition.

The amount of the curing accelerator (C) may be 0% by mass or more than 0% by mass, and is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and even more preferably 0.1% by mass or more, and is preferably 3% by mass or less, more preferably 1% by mass or less, and even more preferably 0.5% by mass or less, based on 100% by mass of the resin component of the resin composition.

((D) Polymer Resin)
The resin composition may further contain a polymer resin (D) as an optional component. The polymer resin (D) as the component (D) does not include those corresponding to the above-mentioned components (A) to (C). The polymer resin (D) may be used alone or in combination of two or more kinds.

(D) Examples of polymer resins include phenoxy resins, acrylic resins, polyimide resins, polyvinyl acetal resins, polyolefin resins, polybutadiene resins, polyamideimide resins, polyetherimide resins, polysulfone resins, polyethersulfone resins, polyphenylene ether resins, polycarbonate resins, polyetheretherketone resins, and polyester resins. Among these, acrylic resins, polyimide resins, polybutadiene resins, polyphenylene ether resins, and polycarbonate resins are preferred, and acrylic resins, polyimide resins, polybutadiene resins, and polyphenylene ether resins are more preferred.

Examples of the phenoxy resin include phenoxy resins having one or more skeletons selected from the group consisting of bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenolacetophenone skeleton, novolac skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton, anthracene skeleton, adamantane skeleton, terpene skeleton, and trimethylcyclohexane skeleton. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. Specific examples of phenoxy resins include "1256" and "4250" manufactured by Mitsubishi Chemical Corporation (both phenoxy resins containing a bisphenol A skeleton); "YX8100" manufactured by Mitsubishi Chemical Corporation (phenoxy resin containing a bisphenol S skeleton); "YX6954" manufactured by Mitsubishi Chemical Corporation (phenoxy resin containing a bisphenol acetophenone skeleton); "FX280" and "FX293" manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YL7500BH30", "YX6954BH30", "YX7553", "YX7553BH30", "YL7769BH30", "YL6794", "YL7213", "YL7290", "YL7482" and "YL7891BH30" manufactured by Mitsubishi Chemical Corporation; and the like.

Examples of acrylic resins include resins containing a (meth)acrylate structure. The acrylic resin may contain a (meth)acrylate structure in the main chain or in the side chain. Here, the term "(meth)acrylate structure" includes both acrylate and methacrylate structures. Specific examples of acrylic resins include Teisan Resin "SG-70L", "SG-708-6", "WS-023", "SG-700AS", "SG-280TEA", "SG-80H", "SG-80H-3", "SG-P3", "SG-600TEA", and "SG-790" manufactured by Nagase ChemteX Corporation; "ME-2000", "W-116.3", "W-197C", "KG-25", and "KG-3000" manufactured by Negami Chemical Industries Co., Ltd.; and "ARUFON UH-2000" manufactured by Toagosei Co., Ltd.

Specific examples of polyimide resins include "SLK-6100" manufactured by Shin-Etsu Chemical Co., Ltd., and "Rikacoat SN20" and "Rikacoat PN20" manufactured by New Japan Chemical Co., Ltd. Specific examples of polyimide resins include modified polyimides such as linear polyimides obtained by reacting bifunctional hydroxyl-terminated polybutadiene, a diisocyanate compound, and a tetrabasic acid anhydride (polyimides described in JP-A-2006-37083), and polysiloxane skeleton-containing polyimides (polyimides described in JP-A-2002-12667 and JP-A-2000-319386, etc.).

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

Examples of polyolefin resins include ethylene-based copolymer resins such as low-density polyethylene, very low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-methyl acrylate copolymer; polyolefin-based polymers such as polypropylene and ethylene-propylene block copolymer.

Examples of polybutadiene resins include hydrogenated polybutadiene skeleton-containing resins, hydroxyl group-containing polybutadiene resins, phenolic hydroxyl group-containing polybutadiene resins, carboxyl group-containing polybutadiene resins, acid anhydride group-containing polybutadiene resins, epoxy group-containing polybutadiene resins, isocyanate group-containing polybutadiene resins, urethane group-containing polybutadiene resins, polyphenylene ether-polybutadiene resins, etc. A part or all of the polybutadiene structure of the polybutadiene resin may be hydrogenated. Specific examples of polybutadiene resins include "Ricon 130MA8", "Ricon 130MA13", "Ricon 130MA20", "Ricon 131MA5", "Ricon 131MA10", "Ricon 131MA17", "Ricon 131MA20", and "Ricon 184MA6" (polybutadiene containing an acid anhydride group) manufactured by Cray Valley Corporation; "GQ-1000" (polybutadiene having hydroxyl and carboxyl groups introduced therein), "G-1000", "G-2000", and "G-3000" (polybutadiene having hydroxyl groups at both ends), "GI-1000", "GI-2000", and "GI-3000" (polybutadiene having hydrogenated hydroxyl groups at both ends) manufactured by Nippon Soda Co., Ltd.; and "FCA-061L" (hydrogenated polybutadiene skeleton epoxy resin) manufactured by Nagase ChemteX Corporation. Specific examples of polybutadiene resins include polyimide resins having a polybutadiene structure, a urethane structure, and an imide structure in the molecule. The polyimide resin can be produced as a linear polyimide resin (polyimides described in JP 2006-37083 A and WO 2008/153208 A) using hydroxyl-terminated polybutadiene, a diisocyanate compound, and a tetrabasic acid anhydride as raw materials. The content of the butadiene structure in the polyimide resin is preferably 60% by mass to 95% by mass, more preferably 75% by mass to 85% by mass. For details of the polyimide resin, the descriptions in JP 2006-37083 A and WO 2008/153208 A can be referred to, and the contents of these documents are incorporated herein.

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

A specific example of a polyetherimide resin is "Ultem" manufactured by GE.

Specific examples of polysulfone resins include polysulfones "P1700" and "P3500" manufactured by Solvay Advanced Polymers.

An example of a polyethersulfone resin is "PES5003P" manufactured by Sumitomo Chemical Co., Ltd.

Specific examples of polyphenylene ether resins include "NORYL SA90" manufactured by SABIC and "OPE-2St 1200" oligophenylene ether styrene resin manufactured by Mitsubishi Gas Chemical Co., Inc.

Examples of polycarbonate resins include hydroxyl group-containing carbonate resins, phenolic hydroxyl group-containing carbonate resins, carboxyl group-containing carbonate resins, acid anhydride group-containing carbonate resins, isocyanate group-containing carbonate resins, and urethane group-containing carbonate resins. Specific examples of polycarbonate resins include Mitsubishi Gas Chemical's "FPC0220," Asahi Kasei Chemicals' "T6002" and "T6001" (polycarbonate diols), and Kuraray's "C-1090," "C-2090," and "C-3090" (polycarbonate diols). Specific examples of polycarbonate resins include polyimide resins having an imide structure, a urethane structure, and a polycarbonate structure in the molecule. The polyimide resin can be produced as a linear polyimide resin using hydroxyl group-terminated polycarbonate, a diisocyanate compound, and a tetrabasic acid anhydride as raw materials. The content of the carbonate structure in the polyimide resin is preferably 60% by mass to 95% by mass, more preferably 75% by mass to 85% by mass. For details of the polyimide resin, refer to the description in International Publication No. 2016/129541, the contents of which are incorporated herein by reference.

A specific example of a polyether ether ketone resin is "Sumiploy K" manufactured by Sumitomo Chemical Co., Ltd.

Examples of polyester resins include polyethylene terephthalate resin, polyethylene naphthalate resin, polybutylene terephthalate resin, polybutylene naphthalate resin, polytrimethylene terephthalate resin, polytrimethylene naphthalate resin, and polycyclohexane dimethyl terephthalate resin.

The (D) polymer resin may be included in the resin composition in a state where it is compatible with resin components other than the (D) polymer resin. Such a compatible (D) polymer resin is usually included in the cured body in a state where it is compatible with resin components other than the (D) polymer resin. The (D) polymer resin may also be included in the resin composition in a particulate state where it is not compatible with resin components other than the (D) polymer resin. Such particulate (D) polymer resin is usually included in the cured body in a particulate state where it is not compatible with resin components other than the (D) polymer resin. Furthermore, a (D) polymer resin that is compatible with resin components other than the (D) polymer resin and a particulate (D) polymer resin may be used in combination.

Examples of particulate polymer resins (D) include acrylic resin particles. Specific examples of acrylic resin particles include resin particles that are insoluble and infusible in organic solvents by chemically crosslinking resins that exhibit rubber elasticity, such as acrylonitrile butadiene rubber, butadiene rubber, and acrylic rubber. Specific examples of commercially available products include XER-91 (manufactured by Japan Synthetic Rubber Co., Ltd.); Staphyloid AC3355, AC3816, AC3816N, AC3832, AC4030, AC3364, and IM101 (all manufactured by Aica Kogyo Co., Ltd.); and Paraloid EXL2655 and EXL2602 (all manufactured by Kureha Chemical Industry Co., Ltd.).

The (D) polymer resin usually has a large molecular weight. Specifically, the range of the weight average molecular weight Mw of the (D) polymer resin is preferably greater than 5000, more preferably 8,000 or more, even more preferably 10,000 or more, even more preferably 20,000 or more, and preferably 100,000 or less, more preferably 70,000 or less, even more preferably 60,000 or less, even more preferably 50,000 or less. The weight average molecular weight Mw can be measured in terms of polystyrene by gel permeation chromatography (GPC).

The amount of the (D) polymer resin in the resin composition can be set within a range that satisfies the above-mentioned requirements (i) to (iii). In one example, the range of the amount of the (D) polymer resin in the resin composition may be 0% by mass or more than 0% by mass, and is preferably 0.1% by mass or more, more preferably 1% by mass or more, and even more preferably 3% by mass or more, and is preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less, based on 100% by mass of the non-volatile components of the resin composition.

The amount of the (D) polymer resin may be 0% by mass or more than 0% by mass, and is preferably 1% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more, and is preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 65% by mass or less, based on 100% by mass of the resin component of the resin composition.

(Amount of resin component containing nitrogen atoms)
A part or all of the resin components contained in the resin composition may contain a nitrogen atom. The resin components containing nitrogen atoms may be one type or two or more types.

The amount of the resin component containing nitrogen atoms can be set within a range that satisfies the above-mentioned requirements (i) to (iii). In one example, the range of the amount of the resin component containing nitrogen atoms in the resin composition is preferably 0.1% by mass or more, more preferably 1% by mass or more, and even more preferably 5% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less, based on 100% by mass of the non-volatile components of the resin composition. When the amount of the resin component containing nitrogen atoms is within the above range, the adhesion between the conductor layer formed on the specific smooth surface and the cured body after the HAST test can be particularly high. In addition, it is usually possible to effectively improve the adhesion before the HAST test, and to improve the dielectric tangent, storage modulus, glass transition temperature, and crosslink density of the cured body.

The range of the amount of the resin component containing nitrogen atoms in the resin composition is preferably 1% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more, and is preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 80% by mass or less, based on 100% by mass of the resin component of the resin composition. When the amount of the resin component containing nitrogen atoms is within the above range, the adhesion between the conductor layer formed on the specific smooth surface and the cured body after the HAST test can be particularly high. In addition, it is usually possible to effectively improve the adhesion before the HAST test, and to improve the dielectric tangent, storage modulus, glass transition temperature, and crosslink density of the cured body.

(E) Optional Additives
The resin composition may further contain an optional additive (E) as an optional non-volatile component. The optional additive (E) may be, for example, an organometallic compound such as an organic copper compound, an organic zinc compound, or an organic cobalt compound; a leveling agent such as a silicone-based leveling agent or an acrylic polymer-based leveling agent; a thickener such as bentone or montmorillonite; an antifoaming agent such as a silicone-based antifoaming agent, an acrylic-based antifoaming agent, a fluorine-based antifoaming agent, or a vinyl resin-based antifoaming agent; an ultraviolet absorbing agent such as a benzotriazole-based ultraviolet absorbing agent; an adhesion improving agent such as urea silane; an adhesion imparting agent such as a triazole-based adhesion imparting agent, a tetrazole-based adhesion imparting agent, or a triazine-based adhesion imparting agent; an antioxidant such as a hindered phenol-based antioxidant; a fluorescent brightening agent such as a stilbene derivative; a fluorine-based anti-oxidant such as a fluorine-based anti-oxidant; Flame retardants such as phosphorus-based flame retardants (e.g., phosphorus ester compounds, phosphazene compounds, phosphinic acid compounds, red phosphorus), nitrogen-based flame retardants (e.g., melamine sulfate), halogen-based flame retardants, and inorganic flame retardants (e.g., antimony trioxide); dispersants such as phosphorus ester dispersants, polyoxyalkylene dispersants, acetylene dispersants, silicone dispersants, anionic dispersants, and cationic dispersants; stabilizers such as borate stabilizers, titanate stabilizers, aluminate stabilizers, zirconate stabilizers, isocyanate stabilizers, carboxylic acid stabilizers, and carboxylic anhydride stabilizers. (E) Optional additives may be used alone or in combination of two or more.

((F) Solvent)
The resin composition may contain a (F) solvent as a volatile component in addition to the non-volatile components such as the above-mentioned components (A) to (E). An organic solvent is usually used as the (F) solvent. Specific examples of the organic solvent include ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester-based solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, and γ-butyrolactone; ether-based solvents such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether, diphenyl ether, and anisole; alcohol-based solvents such as methanol, ethanol, propanol, butanol, and ethylene glycol; 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl diglycol acetate, γ-butyrolactone, and methyl methoxypropionate. Examples of the solvent include ether ester solvents such as ethyl acetate, ester alcohol solvents such as methyl lactate, ethyl lactate, and methyl 2-hydroxyisobutyrate, ether alcohol solvents such as 2-methoxypropanol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol monomethyl ether, and diethylene glycol monobutyl ether (butyl carbitol), amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone, sulfoxide solvents such as dimethyl sulfoxide, nitrile solvents such as acetonitrile and propionitrile, aliphatic hydrocarbon solvents such as hexane, cyclopentane, cyclohexane, and methylcyclohexane, and aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, and trimethylbenzene. The solvent (F) may be used alone or in combination of two or more.

The amount of (F) solvent is not particularly limited. In one example, the amount of (F) solvent relative to 100% by mass of all components of the resin composition can be in the range of 60% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, 15% by mass or less, 10% by mass or less, etc., or can be 0% by mass.

(Characteristics of hardened body)
The cured product according to one embodiment of the present invention is obtained by curing the above-mentioned resin composition. Since the resin composition contains (A) a thermosetting resin, the resin composition is generally thermally cured to obtain a cured product. Generally, among the components contained in the resin composition, volatile components such as (F) a solvent can be volatilized by the heat during thermal curing, but non-volatile components such as components (A) to (E) do not volatilize by the heat during thermal curing. Therefore, the cured product of the resin composition can contain the non-volatile components of the resin composition or their reaction products.

As described above, the cured body has a specific smooth surface. The specific smooth surface not only has an arithmetic mean roughness Ra in a range that satisfies requirement (i), but also preferably has a maximum height Rz in a specific range. Specifically, the range of the maximum height Rz of the specific smooth surface is preferably 2000 nm or less, more preferably 1500 nm or less, even more preferably 1000 nm or less, and preferably 10 nm or more, more preferably 50 nm or more, even more preferably 100 nm or more. When the specific smooth surface of the cured body has a maximum height Rz in the above range, the desired effect of the present invention can be obtained significantly.

The maximum height Rz of the specific smooth surface of the cured body can be measured in accordance with the Japanese Industrial Standards (JIS B0601-2001). The measurement can be performed using a non-contact surface roughness meter (WYKO NT3300, manufactured by Beco Instruments). The UV treatment and silane coupling agent treatment generally do not cause any change in the maximum height Rz of the specific smooth surface of the cured body. Therefore, the maximum height Rz of the specific smooth surface of the cured body can be measured before or after the UV treatment and silane coupling agent treatment. The specific method for measuring the maximum height Rz can be the method described in <Test 4. Measurement of surface roughness Ra and Rz> in the examples below.

A conductor layer can be formed on the specific smooth surface of the cured body. For example, if the arithmetic mean roughness Ra of the specific smooth surface measured before the ultraviolet treatment and the silane coupling agent treatment satisfies the requirement (i), a conductor layer can be formed on the specific smooth surface after the ultraviolet treatment and the silane coupling agent treatment. Also, for example, if the arithmetic mean roughness Ra of the specific smooth surface measured after the ultraviolet treatment and the silane coupling agent treatment satisfies the requirement (i), a conductor layer can be formed on the specific smooth surface. Then, high adhesion can be obtained between the conductor layer thus formed and the cured body after the HAST test.

In one example, when a conductor layer is formed by plating on a specific smooth surface of the cured body and a HAST test is carried out for 100 hours under high temperature and high humidity conditions of 130°C and 85% RH, high adhesion can be obtained between the cured body and the conductor layer after the HAST test. The adhesion can be evaluated by the peel strength, which is the force required to peel the conductor layer from the cured body. In the above example, the peel strength after the HAST test is preferably 0.15 kg/cm or more, more preferably 0.20 kg/cm or more, and even more preferably 0.25 kg/cm or more. The higher the upper limit, the better, and it can be, for example, 2.00 kg/cm or less.

Since high adhesion can be obtained between the cured body and the conductor layer after the HAST test, the decrease in adhesion due to the HAST test can usually be suppressed. Therefore, the adhesion retention rate after the HAST test can be increased. The retention rate can be expressed as the ratio of the peel strength after the HAST test to the peel strength before the HAST test. In the above example, the range of the peel strength retention rate is preferably 35% or more, more preferably 40% or more, even more preferably 45% or more, and particularly preferably 50% or more. The upper limit is preferably 100% or less, but is usually 80% or less.

Normally, high adhesion can be obtained between the cured body and the conductor layer not only after the HAST test but also before the HAST test. In one example, the peel strength before the HAST test is preferably 0.30 kg/cm or more, more preferably 0.35 kg/cm or more, even more preferably 0.40 kg/cm or more, and particularly preferably 0.43 kg/cm or more. The higher the upper limit, the better, and it can be, for example, 2.00 kg/cm or less.

The peel strength between the insulating layer and the conductor layer can be measured in accordance with JIS C6481. In detail, a cut is made in the conductor layer formed on a specific smooth surface of the cured body, surrounding a rectangular portion with a width of 10 mm and a length of 100 mm. One end of this rectangular portion is pulled vertically at room temperature at a speed of 50 mm/min, and the load (kgf/cm) when 35 mm is peeled off can be measured as the peel strength. The specific method for measuring the peel strength can be the method described in <Test 3. Measurement of peel strength (adhesion strength) between the insulating layer and the conductor layer> below.

Taking advantage of the advantage of being able to form a conductor layer with high adhesion on a specific smooth surface as described above, the cured product is preferably used to form a conductor layer on a specific smooth surface, and more preferably used as an insulating layer for forming a conductor layer on a specific smooth surface.

From the viewpoint of obtaining an insulating layer with low transmission loss, it is preferable that the cured body has a low dielectric tangent Df. The specific range of the dielectric tangent Df of the cured body is preferably 0.0200 or less, more preferably 0.0100 or less, even more preferably 0.0080 or less, and particularly preferably 0.0060 or less. The lower limit is preferably as low as possible, and can be, for example, 0.0010 or more.

The dielectric loss tangent of the cured body can be measured by the cavity resonance perturbation method at a measurement frequency of 5.8 GHz and a measurement temperature of 23°C. The specific method for measuring the dielectric loss tangent Df can be the method described in <Test 6. Measurement of dielectric loss tangent> in the examples below.

The method of forming a conductor layer by forming a conductor layer on a specific smooth surface that has been treated with ultraviolet light and a silane coupling agent is preferably applied to a cured product having specific physical properties. Therefore, it is desirable for an insulating layer used in applications in which a conductor layer is formed on a specific smooth surface that has been treated with ultraviolet light and a silane coupling agent as described above to have specific physical properties. Therefore, from the viewpoint of suitable use in such applications, it is preferable that the cured product according to this embodiment has those specific physical properties.

Specifically, the cured body according to this embodiment preferably has a storage modulus in a specific range. The range of the storage modulus of the cured body at 25°C is preferably 0.10 GPa or more, more preferably 0.20 GPa or more, even more preferably 0.30 GPa or more, and preferably 1.30 GPa or less, more preferably 1.20 GPa or less, even more preferably 1.10 GPa or less. Forming a conductor layer on a specific smooth surface that has been treated with ultraviolet light and a silane coupling agent can be used in applications that use an insulating layer having a storage modulus in such a range. Therefore, from the viewpoint of obtaining an insulating layer suitable for that application, it is preferable that the cured body according to this embodiment has a storage modulus in the above range.

The storage modulus of the cured body can be measured by performing dynamic mechanical analysis in a tensile mode under the measurement conditions of a frequency of 1 Hz and a heating rate of 5°C/min. The specific method for measuring the storage modulus can be the method described later in <Test 7. Measurement of storage modulus and glass transition temperature>.

The cured body according to this embodiment preferably has a glass transition temperature Tg in a specific range. The range of the glass transition temperature Tg of the cured body is preferably 130°C or higher, more preferably 140°C or higher, even more preferably 150°C or higher, and preferably 190°C or lower, more preferably 180°C or lower, even more preferably 170°C or lower. Forming a conductor layer on a specific smooth surface that has been treated with ultraviolet light and a silane coupling agent can be used in applications that use an insulating layer having a glass transition temperature Tg in such a range. Therefore, from the viewpoint of obtaining an insulating layer suitable for that application, it is preferable that the cured body according to this embodiment has a glass transition temperature Tg in the above range.

The glass transition temperature Tg of the cured product can be measured by performing dynamic mechanical analysis in a tensile mode under measurement conditions of a frequency of 1 Hz and a heating rate of 5°C/min, and measuring the temperature at which tan δ is maximum as the glass transition temperature Tg. The specific method for measuring the glass transition temperature Tg can be the method described later in <Test 7. Measurement of storage modulus and glass transition temperature>.

The cured body according to this embodiment preferably has a crosslink density in a specific range. The range of the crosslink density of the cured body is preferably 0.1×10 ⁻³ mol/cm ³ or more, more preferably 1.0×10 ⁻³ mol/cm ³ or more, even more preferably 2.0×10 ⁻³ mol/cm ³ or more, and preferably 200×10 ⁻³ mol/cm ³ or less, more preferably 150×10 ⁻³ mol/cm ³ or less, and even more preferably 100×10 ⁻³ mol/cm ³ or less. Forming a conductor layer on a specific smooth surface that has been subjected to ultraviolet treatment and silane coupling agent treatment can be used in applications that use an insulating layer having a crosslink density in such a range. Therefore, from the viewpoint of obtaining an insulating layer suitable for that application, it is preferable that the cured body according to this embodiment has a crosslink density in the above range.

The crosslink density of the cured body can be measured by the following method. The cured body is subjected to thermomechanical analysis by a tensile load method under the measurement conditions of a load of 200 mN and a temperature rise rate of 5° C./min to measure the storage modulus and loss modulus. A temperature T is set to be 80 K higher than the glass transition temperature Tg of the cured body, and a measured value E' (unit: GPa, i.e. ×10 ⁹ Pa) of the storage modulus at this temperature T is obtained. The obtained storage modulus E' (Pa) is substituted into the following formula (M1) to calculate the crosslink density n (mol/cm ³ ). A specific method for measuring the crosslink density can be the method described in <Test 5. Measurement of crosslink density n> described later. The crosslink density n can be used as an index indicating the number of crosslink molecules present per unit volume.
n = E' / 3RT (M1)
(In the above formula (M1), T represents a predetermined temperature T (K), E' represents a measured value (Pa) of the storage modulus at the predetermined temperature T (K), and R represents a gas constant of 8,310,000 (Pa·cm ³ /mol·K). Note that the measured value (10 ⁹ Pa) of the shear modulus G' at the predetermined temperature T (K) may also be used as E'/3.)

The crosslink density can be adjusted by the composition of the resin composition. For example, the crosslink density of the cured product can be adjusted by using an appropriate amount of (A) a thermosetting resin having an appropriate active group equivalent, or by using an appropriate amount of (B) an inorganic filler.

There are no limitations on the shape of the cured body. Usually, the cured body is formed in a layer. The specific smooth surface of the layered cured body is usually a plane parallel to the layer plane of the layer of the cured body. From the viewpoint of thinning, the thickness of the layered cured body is preferably 600 μm or less, more preferably 300 μm or less, and even more preferably 100 μm or less. The lower limit of the thickness is not particularly limited, and can be, for example, 5 μm or more, 10 μm or more, 20 μm or more, etc.

<Method of manufacturing the cured product>
The cured product according to the present embodiment can be produced by a production method including a step of curing a resin composition containing a thermosetting resin. Usually, the production method of the cured product includes a step of preparing a resin composition, and curing the prepared resin composition in the step.

The resin composition may be prepared by purchasing from the market, or may be prepared by manufacturing. The resin composition may be prepared, for example, by mixing the above-mentioned components. The above-mentioned components may be mixed in part or in whole simultaneously, or may be mixed in sequence. In the process of mixing each component, the temperature may be appropriately set, and thus heating and/or cooling may be performed temporarily or throughout. In addition, stirring or shaking may be performed in the process of mixing each component.

The prepared resin composition may be molded into an appropriate shape as needed. Typically, the resin composition is molded so as to obtain a cured product having a specific smooth surface. For example, when producing an insulating layer as a cured product, the resin composition may be molded into a layer to obtain a resin composition layer. As a specific example, the resin composition may be applied onto a smooth surface and dried as needed to obtain a resin composition layer. The prepared resin composition layer may also be laminated onto an appropriate substrate to obtain a resin composition layer on the substrate.

After preparing the resin composition, a process of curing the resin composition is carried out. Typically, the resin composition is thermally cured by heating. The specific curing conditions for the resin composition may vary depending on the composition of the resin composition. In one example, the curing temperature is preferably 120°C to 240°C, more preferably 150°C to 220°C, and even more preferably 170°C to 210°C. The curing time may be preferably 5 minutes to 120 minutes, more preferably 10 minutes to 100 minutes, and even more preferably 15 minutes to 100 minutes.

The method for producing a cured product may include preheating the resin composition at a temperature lower than the curing temperature before curing the resin composition. Preheating may be performed, for example, under conditions in which the resin composition is heated at a temperature of typically 50°C to 150°C, preferably 60°C to 140°C, and more preferably 70°C to 130°C for a processing time of typically 5 minutes or more, preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, and even more preferably 15 minutes to 100 minutes.

By curing the resin composition as described above, a cured body having a surface is obtained. When the surface of the cured body thus obtained has an arithmetic mean roughness Ra that satisfies the requirement (i), the surface can function as a specific smooth surface, so that a conductor layer can be formed on the specific smooth surface. Then, the cured body and the conductor layer can achieve high adhesion after the HAST test. That is, when a specific smooth surface having an arithmetic mean roughness Ra that satisfies the requirement (i) is obtained before performing the ultraviolet treatment and the silane coupling agent treatment in this way, the specific smooth surface can usually have an arithmetic mean roughness Ra that satisfies the requirement (i) even after performing the ultraviolet treatment and the silane coupling agent treatment. Therefore, by performing the ultraviolet treatment and the silane coupling agent treatment on the specific smooth surface of the cured body and then forming a conductor layer, high adhesion can be achieved after the HAST test.
However, in the case where a specific smooth surface having an arithmetic mean roughness Ra satisfying requirement (i) is obtained after the ultraviolet treatment and silane coupling agent treatment described below, the cured body obtained immediately after curing the resin composition does not necessarily have a specific smooth surface having an arithmetic mean roughness Ra satisfying requirement (i).

The method for producing a cured body may include a step of adjusting the arithmetic mean roughness Ra of the surface of the cured body as necessary. For example, the method for producing a cured body may include a step of performing a desmearing process on the cured body. As a specific example, when a hole such as a via hole is formed in an insulating layer as a cured body, a smear (resin residue) may be formed in the hole, and therefore a desmearing process may be performed to remove the smear. This desmearing process generally not only removes the smear but also roughens the surface of the cured body. Therefore, the desmearing process can adjust the arithmetic mean roughness Ra of the surface of the cured body including the specific smooth surface to be large. This desmearing process is preferably performed so that a specific smooth surface having an arithmetic mean roughness Ra in a range that satisfies the requirement (i) is obtained after the desmearing process. As a method for the desmearing process, for example, a method in which a swelling process using a swelling liquid, a roughening process using an oxidizing agent, and a neutralization process using a neutralizing liquid are performed on the cured body in this order can be mentioned.

Examples of the swelling liquid used in the roughening treatment include an alkaline solution, a surfactant solution, etc., and an alkaline solution is preferred. As the alkaline solution, a sodium hydroxide solution and a potassium hydroxide solution are more preferred. Examples of commercially available swelling liquids include "Swelling Dip Securigans P" and "Swelling Dip Securigans SBU" manufactured by Atotech Japan. The swelling treatment using a swelling liquid can be carried out, for example, by immersing the hardened body in a swelling liquid at 30°C to 90°C for 1 to 20 minutes. From the viewpoint of suppressing the swelling of the resin of the hardened body to an appropriate level, it is preferable to immerse the hardened body in a swelling liquid at 40°C to 80°C for 5 to 15 minutes.

The oxidizing agent used in the roughening treatment can be, for example, an alkaline permanganate solution in which potassium permanganate or sodium permanganate is dissolved in an aqueous solution of sodium hydroxide. The roughening treatment using an oxidizing agent such as an alkaline permanganate solution is preferably carried out by immersing the hardened body in an oxidizing agent solution heated to 60°C to 100°C for 10 to 30 minutes. The concentration of permanganate in the alkaline permanganate solution is preferably 5% by mass to 10% by mass. Commercially available oxidizing agents include, for example, alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securigans P" manufactured by Atotech Japan.

The neutralizing solution used in the roughening treatment is preferably an acidic aqueous solution, and a commercially available product is, for example, "Reduction Solution Securigant P" manufactured by Atotech Japan. Treatment with a neutralizing solution can be carried out by immersing the surface that has been roughened with an oxidizing agent in a neutralizing solution at 30°C to 80°C for 5 to 30 minutes. From the standpoint of workability, etc., it is preferable to immerse the object that has been roughened with an oxidizing agent in a neutralizing solution at 40°C to 70°C for 5 to 20 minutes.

The method for producing a cured body may further include a step of subjecting the cured body to ultraviolet light treatment. When the method for producing a cured body includes a step of performing a desmear treatment, the ultraviolet light treatment is usually performed after the desmear treatment. The ultraviolet light treatment includes irradiating the cured body with ultraviolet light. Specifically, the specific smooth surface of the cured body or the surface on which the specific smooth surface is to be formed is irradiated with ultraviolet light. This ultraviolet light treatment can generate functional groups on the surface of the cured body.

The wavelength of the irradiated ultraviolet light is preferably 160 nm or more, more preferably 172 nm or more, and preferably 350 nm or less, more preferably 300 nm or less. The irradiation time of the ultraviolet light is preferably 1 second or more, more preferably 2 seconds or more, and preferably 300 seconds or less, more preferably 20 seconds or less.

The method for producing a cured body may further include a step of treating the cured body with a silane coupling agent. The silane coupling agent treatment is usually performed after the ultraviolet light treatment. The silane coupling agent treatment involves contacting the cured body with a treatment liquid containing a silane coupling agent. Specifically, the treatment liquid is contacted with the specific smooth surface of the cured body or the surface on which the specific smooth surface is to be formed. This silane coupling agent treatment can fix the silane coupling agent to the surface of the cured body.

Silane coupling agents usually contain silicon atoms, functional groups capable of reacting with inorganic materials to form bonds, and functional groups capable of reacting with resin components to form bonds. Functional groups capable of reacting with inorganic materials to form bonds also include those that, when hydrolyzed, produce groups (such as silanol groups) capable of reacting with inorganic materials to form bonds. Examples of functional groups capable of reacting with inorganic materials to form bonds include alkoxy groups, acetoxy groups, and chlorine atoms. Examples of functional groups capable of reacting with resin components to form bonds include amino groups, glycidyl groups, and mercapto groups.

As the silane coupling agent, an amine-based silane coupling agent containing an amino group is preferred. With an amine-based silane coupling agent, the amino group can bond strongly with the resin component, so high adhesion can be obtained. Examples of preferred amine-based silane coupling agents include an aliphatic amine-based silane coupling agent containing an amino group (aliphatic amino group) bonded to an aliphatic hydrocarbon group; an aromatic amine-based silane coupling agent containing an amino group (aromatic amino group) bonded to an aromatic hydrocarbon group; and the like.

Examples of aliphatic amine-based silane coupling agents include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, and 1-(3-triethoxysilylpropyl)-2-imidazoline. Examples of aromatic amine-based silane coupling agents include N-phenyl-3-aminopropyltrimethoxysilane.

A single type of silane coupling agent may be used alone, or two or more types may be used in combination.

The amount of silane coupling agent in the treatment solution is preferably 1 g/L or more, more preferably 3 g/L or more, even more preferably 5 g/L or more, and is preferably 500 g/L or less, more preferably 300 g/L or less, even more preferably 100 g/L or less.

The treatment liquid usually contains a solvent in combination with the silane coupling agent. The solvent is preferably one that can dissolve the silane coupling agent. Examples of such solvents include water and organic solvents. Of these, it is preferable that the solvent contains water. When the solvent contains water, it is possible to hydrolyze the functional groups of the silane coupling agent to generate highly reactive groups such as silanol groups.

Preferred organic solvents include ketone-based solvents and glycol-based solvents, and among these, glycol-based solvents are more preferable. Among glycol-based solvents, glycol ether-based solvents are preferable, glycol butyl ether-based solvents are more preferable, and one or more selected from the group consisting of ethylene-based glycol butyl ethers and propylene-based glycol butyl ethers are even more preferable.

The ethylene glycol butyl ether is preferably a solvent represented by C ₄ H ₉ —(OC ₂ H ₄ ) _n1 —OH, where n1 represents an integer of 1 or more, and preferably an integer of 1 to 4. Specific examples of the ethylene glycol butyl ether include ethylene glycol butyl ether (n1=1), diethylene glycol butyl ether (n1=2), triethylene glycol butyl ether (n1=3), and tetraethylene glycol butyl ether (n1=4).

The propylene-based glycol butyl ether is preferably a solvent represented by the formula C ₄ H ₉ --(OC ₃ H ₆ ) _n2 --OH, where n2 represents an integer of 1 or more, and preferably an integer of 1 to 4. Specific examples of the propylene-based glycol butyl ether include propylene glycol butyl ether (n2=1), dipropylene glycol butyl ether (n2=2), tripropylene glycol butyl ether (n2=3), and tetrapropylene glycol butyl ether (n2=4).

Among the above examples, ethylene glycol butyl ethers are preferred, and diethylene glycol butyl ethers (e.g., diethylene glycol mono-n-butyl ether, etc.) are more preferred.

In addition, in the glycol butyl ether solvent, the butyl group may be linear or branched. Furthermore, it is preferable to use a glycol butyl ether solvent having a butyl group at the end, as this improves the permeability.

The solvent may be used alone or in combination of two or more. For example, water and an organic solvent may be used in combination. When water and an organic solvent such as a glycol-based solvent are used in combination, the amount of the organic solvent in the treatment liquid is preferably 0.1 g/L or more, more preferably 10 g/L or more, even more preferably 50 g/L or more, and is preferably 600 g/L or less, more preferably 500 g/L or less, even more preferably 400 g/L or less.

The treatment liquid may contain a pH adjuster. The pH of the treatment liquid can be easily adjusted to an appropriate range by using the pH adjuster. Examples of pH adjusters include amine compounds such as diethylenetriamine; sulfuric acid; and alkaline solutions such as NaOH.

The pH adjusters may be used alone or in combination of two or more.

The amount of pH adjuster in the treatment solution can be set so as to obtain a treatment solution with the desired pH. In one example, the amount of pH adjuster ranges preferably from 3 g/L or more, more preferably from 5 g/L or more, and preferably from 50 g/L or less, more preferably from 30 g/L or less.

The treatment liquid may contain any additive as long as it does not significantly impair the effect of the present invention. Examples of the optional additive include a dissolution aid that promotes dissolution of the silane coupling agent; a fluorine compound; a surfactant; and the like. The optional additive may not contain a fluorine compound or a surfactant. Furthermore, the optional additive may be used alone or in combination of two or more types.

The treatment liquid preferably has a pH in a specific range. The specific range of the treatment liquid is preferably 3.0 or more, more preferably 3.5 or more, even more preferably 4.5 or more, and preferably 10.0 or less, more preferably 9.0 or less, even more preferably 7.0 or less, even more preferably 5.5 or less.

The temperature of the treatment liquid that is brought into contact with the hardened body is, for example, 40°C to 80°C. The contact time between the hardened body and the treatment liquid is, for example, 1 minute to 20 minutes. There are no limitations on the method of contacting the hardened body with the treatment liquid, and for example, the contact may be performed by immersing the hardened body in the treatment liquid.

When ultraviolet light treatment and silane coupling agent treatment are performed as described above, a specific smooth surface can be obtained as the surface that has been treated with ultraviolet light and silane coupling agent. A conductor layer can be formed on this specific smooth surface. Furthermore, the cured body and the conductor layer can achieve high adhesion after the HAST test.

The method for producing the cured body may further include any step in combination with the steps described above. For example, it may include a step of subjecting the cured body to a heat treatment after the ultraviolet treatment and the silane coupling agent treatment. The heat treatment can effectively increase the adhesion between the cured body and the conductor layer. The temperature condition for the heat treatment is preferably 120°C or higher, more preferably 130°C or higher, and even more preferably 140°C or higher, and preferably 180°C or lower. The treatment time for the heat treatment is preferably in the range of 5 to 30 minutes.

<Applications of the hardened body>
The cured body according to the present embodiment can be used for insulation purposes, and can be particularly preferably used as a cured body for forming an insulating layer (cured body for forming an insulating layer). For example, the cured body according to the present embodiment can be particularly preferably used as a cured body for forming an insulating layer of a semiconductor chip package (cured body for the insulating layer of a semiconductor chip package) and a cured body for forming an insulating layer of a circuit board (including a printed wiring board) (cured body for the insulating layer of a circuit board). In particular, the cured body is particularly suitable for forming an interlayer insulating layer provided between conductor layers.

Examples of semiconductor chip packages include FC-CSP, MIS-BGA package, ETS-BGA package, Fan-out type WLP (Wafer Level Package), Fan-in type WLP, Fan-out type PLP (Panel Level Package), and Fan-in type PLP.

The cured product may also be used as an underfill material, for example, as a molding underfilling (MUF) material used after connecting a semiconductor chip to a substrate.

Furthermore, the cured product can be used in a wide range of applications where materials obtained by curing a resin composition are used, such as solder resist, die bonding material, semiconductor encapsulation material, hole filling material, and component embedding material.

<Resin sheet>
When the cured body is applied to the above-mentioned uses, the resin composition as a raw material of the cured body may be prepared in the form of a resin sheet. The resin sheet includes a support and a resin composition layer formed on the support. The resin composition layer contains the resin composition, and preferably contains only the resin composition.

From the viewpoint of thinning, the thickness of the resin composition layer is preferably 600 μm or less, more preferably 300 μm or less, and even more preferably 100 μm or less. The lower limit of the thickness of the resin composition layer is not particularly limited, but may be 5 μm or more, 10 μm or more, etc.

Examples of the support include films made of plastic materials, metal foils, and release paper, with films made of plastic materials and metal foils being preferred.

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

When a metal foil is used as the support, examples of the metal foil include copper foil and aluminum foil, with copper foil being preferred. As the copper foil, a foil made of a single metal, copper, or an alloy of copper and another metal (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) may be used.

The support may be subjected to a matte treatment, corona treatment, or antistatic treatment on the surface that is to be bonded to the resin composition layer.

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

The thickness of the support is not particularly limited, but is preferably in the range of 5 μm to 75 μm, and more preferably in the range of 10 μm to 60 μm. When using a support with a release layer, it is preferable that the thickness of the entire support with the release layer is in the above range.

Here, a first test is described in which the resin composition layer of the resin sheet is cured to form a cured body, and the surface of the cured body on the support side is treated with ultraviolet light and a silane coupling agent. The cured body formed in the first test is a sample for identifying the attributes of the resin sheet, and may be referred to as a "sample cured body" hereinafter. When this first test is performed, the surface of the sample cured body on the support side preferably forms a specific smooth surface having an arithmetic mean roughness Ra that satisfies requirement (i). Here, the surface of the sample cured body on the support side refers to the surface of the sample cured body that was bonded to the support. In the first test, the curing of the resin composition layer may be performed under conditions according to the application of the resin sheet, for example, at 170°C for 30 minutes. The ultraviolet irradiation treatment may be performed by irradiating the sample cured body with ultraviolet light having a wavelength of 172 nm for 10 seconds. Furthermore, the silane coupling agent treatment may be performed by immersing the sample cured body in a treatment liquid, which is an aqueous solution containing 5 g/L of 3-amino-propyltrimethoxysilane and 350 g/L of diethylene glycol-mono-n-butyl ether at pH 5.0, at 40°C for 10 minutes. The support is peeled off before the resin composition layer is cured or before the ultraviolet treatment.

In this way, when the first test is performed, it is preferable that the surface of the sample cured body on the support side forms the above-mentioned specific smooth surface having an arithmetic mean roughness Ra in the specific range described in requirement (i). In addition, it is more preferable that the surface of the sample cured body on the support side has the same characteristics as the above-mentioned specific smooth surface in addition to the arithmetic mean roughness Ra. Furthermore, it is even more preferable that the sample cured body has the same characteristics as the cured body according to the present embodiment described above. If a resin sheet that can satisfy such requirements is used in the first test, an insulating layer as the cured body according to the embodiment described above can be easily manufactured. From the viewpoint of obtaining such a resin sheet, it is preferable that the surface of the support that contacts the resin composition layer is smooth. For example, the range of surface roughness of the surface of the support that contacts the resin composition layer may be the same as the range of surface roughness of the specific smooth surface.

A second test will be described in which the resin composition layer of the resin sheet is cured at 200°C for 90 minutes to form a cured sample layer. In this case, the surface of the cured sample layer on the support side preferably has a contact angle X that satisfies requirement (ii). That is, the contact angle X of diethylene glycol-mono-n-butyl ether on the surface on the support side is preferably within the specific range described in requirement (ii). The surface on the support side refers to the surface of the cured sample layer that was bonded to the support. By using such a resin sheet, an insulating layer can be easily manufactured as a cured body according to the above-mentioned embodiment.

Furthermore, when a second test is performed in which the resin composition layer of the resin sheet is cured under conditions of 200°C for 90 minutes to form a cured sample layer, the support-side surface of the cured sample layer preferably has a nitrogen atom concentration that satisfies requirement (iii). That is, the nitrogen atom concentration obtained based on the peak area of the N1s spectrum in X-ray photoelectron spectroscopy analysis of the support-side surface is preferably within the specific range described in requirement (iii). By using such a resin sheet, an insulating layer can be easily manufactured as a cured body according to the above-mentioned embodiment.

In one embodiment, the resin sheet may further include an optional layer as necessary. For example, such an optional layer may be a protective film similar to the support provided on the surface of the resin composition layer that is not bonded to the support (i.e., the surface opposite the support). The thickness of the protective film is not particularly limited, but is, for example, 1 μm to 40 μm. The protective film can prevent dirt from adhering to the surface of the resin composition layer and scratches.

The resin sheet can be produced, for example, by preparing a liquid (varnish-like) resin composition as is or by dissolving the resin composition in a solvent to prepare a liquid (varnish-like) resin composition, applying this onto a support using a coating device such as a die coater, and then drying to form a resin composition layer.

Examples of the solvent include the same as the (F) solvent described as a component of the resin composition. One type of solvent may be used alone, or two or more types may be used in combination.

Drying may be performed by a drying method such as heating or blowing hot air. There are no particular limitations on the drying conditions, but drying is usually performed so that the solvent content in the resin composition layer is 10% by mass or less, preferably 5% by mass or less. Although it varies depending on the boiling point of the solvent in the resin composition, for example, when using a resin composition containing 30% by mass to 60% by mass of solvent, the resin composition layer can be formed by drying at 50°C to 150°C for 3 to 10 minutes.

The resin sheet can be stored in a roll. If the resin sheet has a protective film, it can usually be used by peeling off the protective film.

<Circuit board>
A circuit board according to an embodiment of the present invention includes an insulating layer formed from the above-mentioned cured body. The insulating layer includes the above-mentioned cured body, and preferably includes only the above-mentioned cured body. This circuit board can be manufactured, for example, by a manufacturing method including the following steps (I) and (II).
(I) A step of forming a resin composition layer on an inner layer substrate.
(II) A step of curing the resin composition layer to form an insulating layer as a cured product.

The "inner layer substrate" used in step (I) is a member that serves as the base material of a circuit board, and examples thereof include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, and thermosetting polyphenylene ether substrates. The substrate may have a conductor layer on one or both sides, and the conductor layer may be patterned. An inner layer substrate having a conductor layer (circuit) formed on one or both sides of the substrate may be called an "inner layer circuit substrate." In addition, intermediate products on which an insulating layer and/or a conductor layer is to be formed during the manufacture of a circuit substrate are also included in the above-mentioned "inner layer substrate." When the circuit substrate is a component-embedded circuit board, an inner layer substrate with a component embedded may be used.

The resin composition layer can be formed on the inner layer substrate by, for example, laminating the inner layer substrate and the resin sheet. The inner layer substrate and the resin sheet can be laminated, for example, by heat-pressing the resin sheet to the inner layer substrate from the support side. Examples of the member for heat-pressing the resin sheet to the inner layer substrate (hereinafter also referred to as the "heat-pressing member") include a heated metal plate (e.g., a SUS panel) or a metal roll (e.g., a SUS roll). It is preferable to press the heat-pressing member through an elastic material such as heat-resistant rubber so that the resin sheet can sufficiently follow the surface irregularities of the inner layer substrate, rather than directly pressing the resin sheet with the heat-pressing member.

The lamination of the inner layer substrate and the resin sheet may be performed by a vacuum lamination method. In the vacuum lamination method, the heat-pressure bonding temperature is preferably in the range of 60°C to 160°C, more preferably in the range of 80°C to 140°C, the heat-pressure bonding pressure is preferably in the range of 0.098MPa to 1.77MPa, more preferably in the range of 0.29MPa to 1.47MPa, and the heat-pressure bonding time is preferably in the range of 20 seconds to 400 seconds, more preferably in the range of 30 seconds to 300 seconds. The lamination is preferably performed under reduced pressure conditions of 26.7hPa or less.

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

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

The support may be removed between steps (I) and (II), or after step (II).

In step (II), the resin composition layer is cured to form an insulating layer made of a cured product of the resin composition. The surface of the insulating layer thus formed forms a specific smooth surface. This specific smooth surface is usually obtained as the surface of the insulating layer opposite the circuit board. The resin composition layer is usually cured by thermal curing. The specific curing conditions for the resin composition layer may be the conditions described in the manufacturing method for the cured product.

The method for producing a circuit board may include preheating the resin composition layer at a temperature lower than the curing temperature before thermally curing the resin composition layer. The preheating conditions may be the same as those described in the method for producing a cured body.

The method for manufacturing a circuit board usually further includes a step of (V) subjecting the insulating layer to ultraviolet light treatment, a step of (VI) subjecting the insulating layer to a silane coupling agent treatment, and a step of (VII) forming a conductor layer. The method for manufacturing a circuit board may further include a step of (III) drilling holes in the insulating layer, and a step of (IV) subjecting the insulating layer to a desmear treatment. Steps (III) and (IV) are generally performed before steps (V) and (VI). Step (VII) is generally performed after steps (V) and (VI). When the support is removed after step (II), the removal of the support may be performed between steps (II) and (III), between steps (III) and (IV), or between steps (IV) and (V).

Step (III) is a step of drilling holes in the insulating layer. Step (III) allows holes such as via holes and through holes to be formed in the insulating layer. Step (III) may be performed using, for example, a drill, a laser, plasma, etc., depending on the composition of the resin composition used to form the insulating layer. The dimensions and shape of the holes may be appropriately determined depending on the design of the circuit board.

Step (IV) is a step of performing a desmear treatment on the insulating layer. Usually, in this step (IV), the surface of the insulating layer is also roughened. Therefore, the desmear treatment is sometimes called a "roughening treatment." The desmear treatment can be performed, for example, by the method described in the method for producing a cured body.

(V) the step of subjecting the insulating layer to ultraviolet light treatment, and (VI) the step of subjecting the insulating layer to silane coupling agent treatment are carried out after forming the insulating layer by curing the resin composition layer in step (II) and, if necessary, carrying out steps (III) and (IV). Since the conductor layer is usually formed on the surface of the insulating layer opposite the circuit board, in step (V) ultraviolet light treatment is carried out on the surface of the insulating layer opposite the circuit board, and in step (VI) silane coupling agent treatment is carried out on the surface of the insulating layer opposite the circuit board. The ultraviolet light treatment and silane coupling agent treatment can be carried out by the method described in the manufacturing method of the cured body. By carrying out these steps (V) and (VI), the insulating layer can be obtained as a cured body having a specific smooth surface that has been subjected to ultraviolet light treatment and silane coupling agent treatment.

The method for manufacturing a circuit board may include a step of subjecting the insulating layer to a heat treatment after the ultraviolet treatment and the silane coupling agent treatment and before forming the conductor layer. The heat treatment may be performed by the method described in the method for manufacturing a cured body.

Step (VII) is a step of forming a conductor layer, and the conductor layer is formed on the insulating layer. The conductor material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer contains one or more metals selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin and indium. The conductor layer may be a single metal layer or an alloy layer, and examples of the alloy layer include layers formed from alloys of two or more metals selected from the above group (e.g., nickel-chromium alloy, copper-nickel alloy and copper-titanium alloy). Among them, from the viewpoints of versatility, cost, ease of patterning, etc. of the conductor layer formation, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or an alloy layer of a nickel-chromium alloy, a copper-nickel alloy, or a copper-titanium alloy is preferred, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or an alloy layer of a nickel-chromium alloy is more preferred, and a single metal layer of copper is even more preferred.

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

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

In one embodiment, the conductor layer may be formed by plating. For example, a specific smooth surface of the insulating layer may be plated by a conventionally known technique such as a semi-additive method or a full-additive method to form a conductor layer having a desired wiring pattern. From the viewpoint of ease of production, the semi-additive method is preferred. Below, an example of forming a conductor layer by a semi-additive method is shown.

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

By forming the conductor layer as described above, a circuit board can be manufactured that includes the insulating layer as the cured body described above and a conductor layer formed on a specific smooth surface of the insulating layer. The circuit board manufactured in this manner has excellent adhesion between the insulating layer and the conductor layer, and can achieve particularly high adhesion after the HAST test.

The method for manufacturing a circuit board may be carried out by repeating the formation of insulating layers and conductor layers in steps (I) to (VII) as necessary. By repeating the formation of insulating layers and conductor layers, a circuit board having a multilayer structure such as a multilayer printed wiring board can be manufactured.

<Semiconductor chip package>
A semiconductor chip package according to an embodiment of the present invention includes the above-mentioned cured body and a semiconductor chip. Usually, the semiconductor chip package includes an insulating layer formed of the cured body. The insulating layer includes the above-mentioned cured body, and preferably includes only the above-mentioned cured body of the resin composition. Examples of this semiconductor chip package include the following.

The semiconductor chip package according to the first example includes the circuit board described above and a semiconductor chip mounted on the circuit board. This semiconductor chip package can be manufactured by joining the semiconductor chip to the circuit board.

The bonding conditions between the circuit board and the semiconductor chip can be any conditions that allow a conductive connection between the terminal electrodes of the semiconductor chip and the circuit wiring of the circuit board. For example, the conditions used in flip-chip mounting of the semiconductor chip can be used. Also, for example, the semiconductor chip and the circuit board can be bonded via an insulating adhesive.

An example of a bonding method is a method in which a semiconductor chip is pressure-bonded to a circuit board. Pressure-bonding conditions include a pressure temperature that is usually in the range of 120°C to 240°C (preferably in the range of 130°C to 200°C, more preferably in the range of 140°C to 180°C), and a pressure-bonding time that is usually in the range of 1 second to 60 seconds (preferably in the range of 5 seconds to 30 seconds).

Another example of a bonding method is to bond a semiconductor chip to a circuit board by reflow. Reflow conditions may be in the range of 120°C to 300°C.

After the semiconductor chip is bonded to the circuit board, the semiconductor chip may be filled with a molded underfill material.

The semiconductor chip package according to the second example includes a semiconductor chip and an insulating layer formed of a cured body. Examples of the semiconductor chip package according to the second example include a fan-out type WLP and a fan-out type PLP.

Figure 1 is a cross-sectional view showing a schematic diagram of a fan-out type WLP as an example of a semiconductor chip package according to an embodiment of the present invention. For example, as shown in Figure 1, a semiconductor chip package 100 as a fan-out type WLP includes a semiconductor chip 110; a sealing layer 120 formed to cover the periphery of the semiconductor chip 110; a rewiring formation layer 130 as an insulating layer provided on the surface of the semiconductor chip 110 opposite the sealing layer 120; a rewiring layer 140 as a conductor layer; a solder resist layer 150; and bumps 160.

The method for manufacturing such a semiconductor chip package includes:
(i) laminating a temporary fixing film on a substrate;
(ii) a step of temporarily fixing a semiconductor chip on a temporary fixing film;
(iii) forming an encapsulation layer on the semiconductor chip;
(iv) peeling the substrate and the temporary fixing film from the semiconductor chip;
(v) forming a rewiring formation layer on the surface of the semiconductor chip from which the base material and the temporary fixing film have been peeled off;
(vi) forming a redistribution layer as a conductor layer on the redistribution layer; and
(vii) forming a solder resist layer on the rewiring layer;
The method for manufacturing the semiconductor chip package further comprises:
(viii) dicing the plurality of semiconductor chip packages into individual semiconductor chip packages.

(Step (i))
Step (i) is a step of laminating a temporary fixing film on a substrate. The lamination conditions for the substrate and the temporary fixing film can be the same as the lamination conditions for the inner layer substrate and the resin sheet in the method for producing a circuit board.

Examples of substrates include silicon wafers; glass wafers; glass substrates; metal substrates such as copper, titanium, stainless steel, and cold-rolled steel plate (SPCC); substrates such as FR-4 substrates in which glass fibers are impregnated with epoxy resin or the like and then heat-cured; and substrates made of bismaleimide triazine resins such as BT resin.

The temporary fixing film can be made of any material that can be peeled off from the semiconductor chip and can temporarily fix the semiconductor chip. Commercially available products include "Riva Alpha" manufactured by Nitto Denko Corporation.

(Step (ii))
Step (ii) is a step of temporarily fixing the semiconductor chip on the temporary fixing film. The temporary fixing of the semiconductor chip can be performed using, for example, a device such as a flip chip bonder or a die bonder. The layout and number of the semiconductor chips can be appropriately set depending on the shape and size of the temporary fixing film, the number of semiconductor chip packages to be produced, etc. For example, the semiconductor chips may be temporarily fixed by arranging them in a matrix shape of multiple rows and multiple columns.

(Step (iii))
Step (iii) is a step of forming an encapsulating layer on the semiconductor chip. The encapsulating layer can be formed, for example, by a photosensitive resin composition or a thermosetting resin composition. This encapsulating layer may be formed by the cured body according to the above-mentioned embodiment. The encapsulating layer can usually be formed by a method including a step of forming a resin composition layer on the semiconductor chip and a step of curing this resin composition layer to form the encapsulating layer.

(Step (iv))
Step (iv) is a step of peeling off the substrate and the temporary fixing film from the semiconductor chip. It is desirable to adopt an appropriate peeling method according to the material of the temporary fixing film. For example, the peeling method may be a method of heating, foaming or expanding the temporary fixing film to peel it off. In addition, for example, the peeling method may be a method of irradiating the temporary fixing film with ultraviolet light through the substrate to reduce the adhesive strength of the temporary fixing film to peel it off.

When the substrate and the temporary fixing film are peeled off from the semiconductor chip as described above, the surface of the sealing layer is exposed. The manufacturing method of the semiconductor chip package may include polishing the exposed surface of the sealing layer. Polishing can improve the smoothness of the surface of the sealing layer.

(Step (v))
Step (v) is a step of forming a rewiring formation layer as an insulating layer on the surface of the semiconductor chip from which the base material and the temporary fixing film are peeled off. Usually, this rewiring formation layer is formed on the semiconductor chip and the sealing layer. The rewiring formation layer can be formed by the cured body according to the above-mentioned embodiment. Usually, the rewiring formation layer can be formed by a method including a step of forming a resin composition layer on the semiconductor chip, a step of curing the resin composition layer to form the rewiring formation layer, a step of subjecting the rewiring formation layer to ultraviolet treatment, and a step of subjecting the rewiring formation layer to a silane coupling agent treatment.

The formation of the resin composition layer on the semiconductor chip can be carried out in the same manner as the formation of the resin composition layer on the inner layer substrate described in the above-mentioned method for producing a circuit board, except that, for example, a semiconductor chip is used instead of the inner layer substrate.

After forming a resin composition layer on the semiconductor chip, the resin composition layer is cured to obtain a rewiring formation layer as an insulating layer. The curing conditions for the resin composition layer may be the same as those described in the method for producing a cured product. When the resin composition layer is thermally cured, the resin composition layer may be preheated at a temperature lower than the curing temperature before the thermal curing. The preheating conditions may be the same as those described in the method for producing a cured product.

After forming the redistribution layer, the surface of the redistribution layer is treated with ultraviolet light and a silane coupling agent. After the silane coupling agent treatment, the redistribution layer may be heat-treated. The ultraviolet light treatment, silane coupling agent treatment, and heat treatment may be performed by the method described in the method for producing a cured body. A conductor layer can be formed with high adhesion on the surface of the redistribution layer, which has been treated with ultraviolet light and a silane coupling agent and serves as a specific smooth surface.

After forming the redistribution layer, holes may be formed in the redistribution layer to connect the semiconductor chip and the redistribution layer. The hole formation is usually performed before the ultraviolet light treatment.

(Step (vi))
Step (vi) is a step of forming a redistribution layer as a conductor layer on the redistribution formation layer. The method of forming the redistribution layer on the redistribution formation layer can be the same as the method of forming a conductor layer on an insulating layer in the manufacturing method of a circuit board. In addition, steps (v) and (vi) may be repeated to alternately stack the redistribution layer and the redistribution formation layer (build up).

(Step (vii))
Step (vii) is a step of forming a solder resist layer on the rewiring layer. The material of the solder resist layer can be any material having insulating properties. Among them, from the viewpoint of ease of manufacturing the semiconductor chip package, a photosensitive resin composition and a thermosetting resin composition are preferred. The solder resist layer may be formed by the cured body according to the above-mentioned embodiment.

In step (vii), bumping processing may be performed to form bumps, if necessary. The bumping processing may be performed by a method such as solder balls or solder plating. In addition, the formation of via holes in the bumping processing may be performed in the same manner as in step (v).

(Step (viii))
The method for manufacturing a semiconductor chip package may include a step (viii) in addition to the steps (i) to (vii). The step (viii) is a step of dicing a plurality of semiconductor chip packages into individual semiconductor chip packages to separate them. The method for dicing the semiconductor chip packages into individual semiconductor chip packages is not particularly limited.

<Semiconductor Device>
The semiconductor device includes the circuit board or semiconductor chip package described above. Examples of the semiconductor device include various semiconductor devices used in electrical products (e.g., computers, mobile phones, smartphones, tablet devices, wearable devices, digital cameras, medical devices, televisions, etc.) and vehicles (e.g., motorcycles, automobiles, trains, ships, aircraft, etc.).

The present invention will be specifically described below with reference to examples. However, the present invention is not limited to these examples. In the following description, the terms "parts" and "%" used to indicate amounts refer to "parts by mass" and "% by mass", respectively, unless otherwise specified. Furthermore, the operations described below were carried out in the atmosphere at room temperature and normal pressure (25°C and 1 atm) unless otherwise specified.

In the following examples, the glycidylamine epoxy resin "JER630LSD", the phenolic curing agent "LA-3018-50P", the maleimide compound "SLK-6895-M90", the bismaleimide resin "BMI-3000", the curing accelerator "1B2PZ", the polymer resin A synthesized in Synthesis Example 1, and the polymer resin D synthesized in Synthesis Example 2 correspond to the resin components containing nitrogen atoms.

Synthesis Example 1: Synthesis of polymer resin A
A flask equipped with a stirrer, a thermometer, and a condenser was charged with 271.7 parts by mass of propylene glycol methyl ether acetate (PGMAc), 14.1 parts by mass (0.064 mol) of isophorone diisocyanate (IPDI), and 112.2 parts by mass (0.03 mol) of polybutadiene having OH groups at both ends ("G-3000" manufactured by Nippon Soda Co., Ltd., hydroxyl value: 30 mgKOH/g) to obtain a mixed solution. The mixed solution was heated to 50° C. and then maintained at this temperature for 1 hour. Next, after confirming that the amount of isocyanate groups was equal to or less than a predetermined value, 145.2 parts by mass (0.09 mol) of oligophenylene ether resin containing phenolic hydroxyl groups at both ends ("SA90-100" manufactured by Sabic, hydroxyl group equivalent: 807 g/mol) and 1 part by mass (0.003 mol) of benzophenone tetracarboxylic dianhydride (BTDA) were added to the above mixed solution. Thereafter, the mixed solution was heated to 140° C., and the reaction was continued for 4 hours. The characteristic absorption was measured by infrared spectroscopy, and the reaction was terminated when it was confirmed that the absorption peak at 2270 cm ⁻¹ , which is the characteristic absorption of the isocyanate group, had completely disappeared and the increase in viscosity had subsided.
In this manner, polymer resin A having a structure in which the molecular ends are sealed with a phenol resin (oligophenylene ether resin containing phenolic hydroxyl groups at both ends) was synthesized, and a solution of polymer resin A was obtained. The weight average molecular weight of polymer resin A was 15,000, and the content of non-volatile components in the solution of polymer resin A was 50 mass%.

Synthesis Example 2: Synthesis of polymer resin D
A reaction vessel equipped with a stirrer, a water divider, a thermometer, and a nitrogen gas inlet tube was charged with 65.0 g of aromatic tetracarboxylic dianhydride (SABIC Japan "BisDA-1000", 4,4'-(4,4'-isopropylidenediphenoxy)bisphthalic dianhydride), 266.5 g of cyclohexanone, and 44.4 g of methylcyclohexane to obtain a solution. This solution was heated to 60 ° C. Next, 43.7 g of dimer diamine (Croda Japan "PRIAMINE 1075") and 5.4 g of 1,3-bis(aminomethyl)cyclohexane were dropped into the solution, and then the imidization reaction was carried out at 140 ° C. for 1 hour. As a result, a polyimide solution (non-volatile component 30% by mass) containing polymer resin D, which is a polyimide resin, was obtained. The weight average molecular weight of polymer resin D was 25,000.

Example 1
(Manufacture of resin varnish)
Bisphenol type epoxy resin (Nippon Steel Chemical & Material Co., Ltd. "ZX-1059", 1:1 mixture of bisphenol A type and bisphenol F type, epoxy equivalent 169 g/eq.) 3 parts, naphthalene type epoxy resin (DIC Corporation "HP-4032D", 1,6-bis(glycidyloxy)naphthalene, epoxy equivalent approximately 145 g/eq.) 3 parts, inorganic filler 2 (spherical silica (Admatechs Co., Ltd. "SO-C1", average particle size 0.3 μm, specific surface area ¹⁵ m2) surface-treated with an amine-based alkoxysilane compound (Shin-Etsu Chemical Co., Ltd. "KBM573") /g)), 65 parts of a solution of polymer resin A (non-volatile component 50% by mass) 20 parts, a maleimide compound (liquid bismaleimide "SLK-6895-M90" manufactured by Shin-Etsu Chemical Co., Ltd., MEK solution of 90% mass% non-volatile component, maleimide group equivalent 345 g / eq.) 3.3 parts, a phenol-based curing agent ("LA-3018-50P" manufactured by DIC Corporation, non-volatile component 50%, phenolic hydroxyl group equivalent 151 g / eq.) 4 parts, a curing accelerator ("1B2PZ" manufactured by Shikoku Chemical Industry Co., Ltd., 1-benzyl-2-phenylimidazole) 0.05 parts, cyclohexanone 15 parts, and methyl ethyl ketone 6 parts were uniformly dispersed using a mixer to obtain a resin varnish.

(Production of resin sheets)
A polyethylene terephthalate film ("Lumirror T6AM" manufactured by Toray Industries, Inc., thickness 38 μm) was prepared as a support. A resin varnish was uniformly applied onto this support so that the thickness of the resin composition layer after drying would be 50 μm, and the resin composition layer was formed by drying at 80° C. to 120° C. (average 100° C.) for 6 minutes.

A protective film with a rough surface (polypropylene film, Oji F-Tex's "Alphan MA-430", thickness 20 μm) was prepared. The rough surface of this protective film was attached to the resin composition layer to obtain a resin sheet with a layer structure of support/resin composition layer/protective film.

Example 2
Naphthalene type epoxy resin (DIC Corporation "HP-4032D", 1,6-bis(glycidyloxy)naphthalene, epoxy equivalent of about 145 g/eq.) 3 parts, naphthylene ether type epoxy resin (DIC Corporation "HP-6000L", epoxy equivalent of 215 g/eq.) 3 parts, inorganic filler 3 (spherical silica (Admatechs Corporation "SO-C4", average particle size 1.0 μm, specific surface area ^4.5 m2) surface-treated with an amine-based alkoxysilane compound (Shin-Etsu Chemical Co., Ltd. "KBM573") /g)) 90 parts, active ester curing agent (DIC Corporation "EXB8000L-65TM", active group equivalent of about 220 g/eq., toluene/MEK solution with 65% non-volatile content) 1.54 parts, polymer resin A solution (non-volatile content 50% by mass) 40 parts, maleimide compound (Shin-Etsu Chemical Co., Ltd. liquid bismaleimide "SLK-6895-M90", MEK solution with 90% non-volatile content by mass) A resin varnish was obtained by uniformly dispersing 3.3 parts of a phenolic curing agent ("LA-3018-50P" manufactured by DIC Corporation, non-volatile components 50%), 2 parts of a curing accelerator ("1B2PZ" manufactured by Shikoku Chemical Industry Co., Ltd., 1-benzyl-2-phenylimidazole), 15 parts of cyclohexanone, and 6 parts of methyl ethyl ketone using a mixer.

A resin sheet was produced in the same manner as in Example 1, except that the resin varnish thus obtained was used instead of the resin varnish in Example 1.

Example 3
Naphthalene type epoxy resin (DIC "HP-4032D", 1,6-bis(glycidyloxy)naphthalene, epoxy equivalent of about 145 g/eq.) 3 parts, glycidylamine type epoxy resin (Mitsubishi Chemical "JER630LSD", epoxy equivalent of 95 g/eq.) 3 parts, inorganic filler 1 (spherical silica (DENKA "UFP-30", average particle size 1.0 μm, specific surface area ³¹ m2) surface-treated with an amine-based alkoxysilane compound (Shin-Etsu Chemical "KBM573") /g)), 50 parts of cresol novolak resin (DIC Corporation "KA-1160", hydroxyl group equivalent = 117 g / eq.), 3 g of a solution of polymer resin A (non-volatile component 50 mass%), 20 parts of a maleimide compound (Shin-Etsu Chemical Co., Ltd. liquid bismaleimide "SLK-6895-M90", non-volatile component 90% mass% MEK solution, maleimide group equivalent 345 g / eq.), 6.7 parts of a phenol-based curing agent (DIC Corporation "LA-3018-50P", non-volatile component 50%), 2 parts of a curing accelerator (Shikoku Chemical Industry Co., Ltd. "1B2PZ", 1-benzyl-2-phenylimidazole), 15 parts of cyclohexanone, and 6 parts of methyl ethyl ketone were uniformly dispersed using a mixer to obtain a resin varnish.

A resin sheet was produced in the same manner as in Example 1, except that the resin varnish thus obtained was used instead of the resin varnish in Example 1.

Example 4
The resin varnish and the resin sheet were produced in the same manner as in Example 3, except that the solution of polymer resin A was changed to 10 parts of a hydroxyl group-containing acrylic polymer ("ARUFON UH-2000", manufactured by Toagosei Co., Ltd., weight average molecular weight 11,000) as polymer resin B.

Example 5
A resin varnish and a resin sheet were produced in the same manner as in Example 1, except that the solution of polymer resin A was changed to 4 parts of core-shell type polymer particles as polymer resin C (Dow's "EXL2655"; core-shell particles having a core portion formed of a butadiene polymer and a shell portion formed of a copolymer of styrene and methyl methacrylate; average particle size 0.2 μm).

Example 6
A resin varnish and a resin sheet were produced in the same manner as in Example 1, except that the solution of polymer resin A was changed to 33.3 parts of a polyimide solution containing polymer resin D (non-volatile component 30% by mass).

Example 7
The solution of polymer resin A was changed to 5 parts of bismaleimide resin (Designer Molecules'"BMI-3000", molecular weight 3000, maleimide group equivalent 1500 g / eq.). In addition, the amount of maleimide compound (Shin-Etsu Chemical Co., Ltd.'s liquid bismaleimide "SLK-6895-M90", MEK solution with 90% mass% non-volatile components, maleimide group equivalent 345 g / eq.) was changed from 6.7 parts to 3.3 parts. A resin varnish and a resin sheet were produced in the same manner as in Example 3 except for the above items.

<Comparative Example 1>
90 parts of inorganic filler 3 was changed to 100 parts of inorganic filler 4 (spherical silica particles surface-treated with an amine-based alkoxysilane compound ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.), average particle size 2.0 μm, specific surface area 2.0 m ² /g). In addition, the amount of the polymer resin A solution (non-volatile component 50% by mass) was changed from 40 parts to 26 parts. Furthermore, no maleimide compound (liquid bismaleimide "SLK-6895-M90" manufactured by Shin-Etsu Chemical Co., Ltd., MEK solution with 90% by mass of non-volatile component, maleimide group equivalent 345 g/eq.) was used. A resin varnish and a resin sheet were produced in the same manner as in Example 2 except for the above points.

<Comparative Example 2>
Naphthylene ether type epoxy resin (DIC "HP-6000L", epoxy equivalent 215 g/eq.) 3 parts, glycidylamine type epoxy resin (Mitsubishi Chemical "JER630LSD", epoxy equivalent 95 g/eq.) 4 parts, inorganic filler 3 (spherical silica (Admatechs "SO-C4", average particle size 1.0 μm, specific surface area ^4.5 m2) surface-treated with an amine-based alkoxysilane compound (Shin-Etsu Chemical "KBM573") A resin varnish was obtained by uniformly dispersing 90 parts of an active ester curing agent (DIC Corporation's "EXB8000L-65TM", active group equivalent of about 220 g/eq., toluene-MEK solution with 65% nonvolatile content) 1.54 parts of a solution of polymer resin A (50% by mass of nonvolatile content), 14 parts of a phenolic curing agent (DIC Corporation's "LA-3018-50P", nonvolatile content 50%) 8 parts of a curing accelerator (Shikoku Chemical Industry Co., Ltd.'s "1B2PZ", 1-benzyl-2-phenylimidazole), 15 parts of cyclohexanone, and 6 parts of methyl ethyl ketone using a mixer.

A resin sheet was produced in the same manner as in Example 1, except that the resin varnish thus obtained was used instead of the resin varnish in Example 1.

<Comparative Example 3>
Naphthalene type epoxy resin (DIC "HP-4032D", 1,6-bis(glycidyloxy)naphthalene, epoxy equivalent of about 145 g/eq.) 3 parts, epoxy group-containing modified silicone resin (Shin-Etsu Chemical Co., Ltd. "X-22-2000", epoxy equivalent of 620/eq.) 3 parts, inorganic filler 3 (spherical silica (Admatechs Co., Ltd. "SO-C4", average particle size 1.0 μm, specific surface area ^4.5 m2) surface-treated with an amine-based alkoxysilane compound (Shin-Etsu Chemical Co., Ltd. "KBM573") A resin varnish was obtained by uniformly dispersing 90 parts of an active ester curing agent (DIC Corporation's "EXB-8000L-65TM", active group equivalent of about 220 g/eq., toluene-MEK solution with 65% nonvolatile content) 1.54 parts of a solution of polymer resin A (50% by mass of nonvolatile content), 40 parts of a phenolic curing agent (DIC Corporation's "LA-3018-50P", nonvolatile content 50%) 2 parts of a curing accelerator (Shikoku Chemical Industry Co., Ltd.'s "1B2PZ", 1-benzyl-2-phenylimidazole), 15 parts of cyclohexanone, and 6 parts of methyl ethyl ketone using a mixer.

A resin sheet was produced in the same manner as in Example 1, except that the resin varnish thus obtained was used instead of the resin varnish in Example 1.

<Test 1. Measurement of contact angle X>
(Surface treatment of inner layer circuit board)
A glass cloth-based epoxy resin double-sided copper-clad laminate (copper foil thickness 18 μm, substrate thickness 0.4 mm, Panasonic "R1515A") was prepared as an inner layer circuit board, in which an inner layer circuit was formed using copper. Both sides of this inner layer circuit board were etched by 1 μm with a microetching agent (Mec "CZ8101") to roughen the copper surface.

(Formation of hardened sample layer)
The protective film was peeled off from the resin sheet prepared in the examples and comparative examples to expose the resin composition layer. Using a batch type vacuum pressure laminator (two-stage build-up laminator "CVP700" manufactured by Nikko Materials Co., Ltd.), the resin composition layer was laminated on both sides of the inner layer circuit board so that it was in contact with the inner layer circuit board. The lamination was performed by reducing the pressure for 30 seconds to adjust the air pressure to 13 hPa or less, and then pressing at 120 ° C. and a pressure of 0.74 MPa for 30 seconds. Next, a heat press was performed at 100 ° C. and a pressure of 0.5 MPa for 60 seconds. Then, the support was peeled off to expose the resin composition layer.

The resin composition layer was cured at 200°C for 90 minutes to form a cured sample layer on the inner layer circuit board.

The contact angle X of diethylene glycol-mono-n-butyl ether with the surface of the cured sample layer was measured by the droplet method using an automatic contact angle meter (DropMaster DMs-401, manufactured by Kyowa Interface Science Co., Ltd.). Specifically, a syringe was filled with diethylene glycol-mono-n-butyl ether, a 1.0 μL droplet was made, and the droplet was attached to the surface of the cured sample layer. The contact angle X (°) 2000 ms after the diethylene glycol-mono-n-butyl ether was attached was measured using the automatic contact angle meter.

<Test 2. XPS Measurement>
(Surface treatment of inner layer circuit board)
A glass cloth-based epoxy resin double-sided copper-clad laminate (copper foil thickness 18 μm, substrate thickness 0.4 mm, Panasonic "R1515A") was prepared as an inner layer circuit board, in which an inner layer circuit was formed using copper. Both sides of this inner layer circuit board were etched by 1 μm with a microetching agent (Mec "CZ8101") to roughen the copper surface.

(Formation of hardened sample layer)
The protective film was peeled off from the resin sheet prepared in the examples and comparative examples to expose the resin composition layer. Using a batch type vacuum pressure laminator (two-stage build-up laminator "CVP700" manufactured by Nikko Materials Co., Ltd.), the resin composition layer was laminated on both sides of the inner layer circuit board so that it was in contact with the inner layer circuit board. The lamination was performed by reducing the pressure for 30 seconds to adjust the air pressure to 13 hPa or less, and then pressing at 120 ° C. and a pressure of 0.74 MPa for 30 seconds. Next, a heat press was performed at 100 ° C. and a pressure of 0.5 MPa for 60 seconds. Then, the support was peeled off to expose the resin composition layer.

The resin composition layer was cured at 200°C for 90 minutes to form a cured sample layer on the inner layer circuit board.

(XPS Measurement)
The surface of the cured sample layer was subjected to XPS measurement using a scanning X-ray photoelectron spectrometer (ULVAC-PHI, Inc.'s "PHI Quantera II"). The nitrogen atom concentration on the surface of the cured sample layer was determined based on the peak area of the measured N1s spectrum. The XPS measurement was performed under the following measurement conditions.

XPS measurement conditions:
X-ray beam diameter 100 μm, energy 25 W, acceleration voltage 15 kV

<Test 3. Measurement of peel strength (adhesion strength) between insulating layer and conductor layer>
(Sample Preparation)
(1) Surface preparation of inner layer circuit board:
A glass cloth-based epoxy resin double-sided copper-clad laminate (copper foil thickness 18 μm, substrate thickness 0.4 mm, Panasonic "R1515A") was prepared as an inner layer circuit board, in which an inner layer circuit was formed using copper. Both sides of this inner layer circuit board were etched to a depth of 1 μm with a microetching agent (Mec "CZ8101") to roughen the copper surface.

(2) Lamination of resin sheets:
The protective film was peeled off from the resin sheet produced in the examples and comparative examples. This resin sheet was laminated on both sides of the inner layer circuit board using a batch type vacuum pressure laminator ("MVLP-500" manufactured by Meiki Seisakusho Co., Ltd.) so that the resin composition layer was in contact with the inner layer circuit board. The lamination was performed by reducing the pressure for 30 seconds to 13 hPa or less, and then laminating at 100°C and a pressure of 0.74 MPa for 30 seconds.

(3) Curing of resin composition layer:
The laminated resin sheet was heated at 100° C. for 30 minutes and then at 170° C. for 30 minutes to thermally cure the resin composition layer, thereby forming an insulating layer as a cured product. Thereafter, the support was peeled off to obtain an intermediate laminate having a layer structure of insulating layer/inner layer circuit board/insulating layer.

(4) UV treatment:
The support was peeled off and the surface of the insulating layer revealed was irradiated with ultraviolet light having a wavelength of 172 nm at 25° C. for 10 seconds.

(5) Silane coupling treatment:
A silane coupling agent solution (silane coupling agent concentration: 5 g/L, glycol solvent concentration: 350 g/L) was prepared by dissolving a silane coupling agent ("KBM903", manufactured by Shin-Etsu Chemical Co., Ltd.) and a glycol solvent (diethylene glycol mono-n-butyl ether) in water. The pH of the solution was 5.0. The intermediate laminate was immersed in this silane coupling agent solution at 40°C for 10 minutes. Thereafter, the intermediate laminate was dried at 60°C for 10 minutes to obtain sample substrate A.

(6) Heat treatment:
Sample substrate A was subjected to a heat treatment at 160° C. for 10 minutes.

(7) Electroless plating process:
1. Alkaline cleaning:
The surface of the sample substrate A after the heat treatment was cleaned at 60° C. for 5 minutes using Cleaning Cleaner Security 902 (trade name).

2. Soft Etching:
Next, the surface of sample substrate A was treated with an aqueous solution of sodium peroxodisulfate acidified with sulfuric acid at 30° C. for 1 minute.

3. Pre-dip (adjusting the charge on the surface of the insulating layer for Pd application):
Next, the surface of the sample substrate A was treated with Pre. Dip Neogant B (product name) at room temperature for 1 minute.

4. Adding an activator (adding Pd to the surface of the insulating layer):
Next, the surface of sample substrate A was treated with Activator Neogant 834 (product name) at 35° C. for 5 minutes.

5. Reduction (reducing Pd added to the insulating layer):
Next, the surface of the sample substrate A was treated with a mixed solution of Reducer Neogant WA (trade name) and Reducer Accelerator 810 mod. (trade name) at 30° C. for 5 minutes.

6. Electroless copper plating process (precipitating Cu on the surface of the insulating layer (Pd surface)):
Next, the surface of sample substrate A was treated for 20 minutes at 35°C using a mixture of Basic Solution Printganth MSK-DK (trade name), Copper solution Printganth MSK (trade name), Stabilizer Printganth MSK-DK (trade name), and Reducer Cu (trade name). Through the above operations, an electroless copper plating layer (thickness 0.8 μm) was formed on the surface of the insulating layer. Then, a heat treatment was performed at 150°C for 30 minutes.

7. Electrolytic plating process:
Next, an electrolytic copper plating process was performed using a chemical solution manufactured by Atotech Japan to form an electrolytic plating layer. A conductor layer (thickness 25 μm) was formed by combining the electroless copper plating layer and the electrolytic plating layer. Next, an annealing treatment was performed at 200° C. for 90 minutes to obtain a sample substrate B.

(Measurement of Peel Strength Before HAST Test)
The peel strength between the insulating layer and the conductor layer was measured in accordance with JIS C6481 for the sample substrate B. Specifically, the peel strength was measured by the following method.
A cut was made in the conductor layer of sample substrate B surrounding a rectangular portion having a width of 10 mm and a length of 100 mm. One end of this rectangular portion was peeled off and gripped with a gripper. The rectangular portion was peeled off vertically by 35 mm at a speed of 50 mm/min at room temperature with the gripper, and the load (kgf/cm) was measured to determine the peel strength (peel strength before the HAST test). A tensile tester ("AC-50C-SL" manufactured by TSE Corporation) was used for the measurement.

(Measurement of Peel Strength After HAST Test)
Thereafter, a HAST test was performed for 100 hours on sample substrate B under high temperature and high humidity conditions of 130° C. and 85% RH using a highly accelerated life tester ("PM422" manufactured by Kusumoto Chemical Industries, Ltd.) After that, a cut was formed in the conductor layer of sample substrate B after the HAST test in the same manner as in the above process (measurement of peel strength before HAST test), and the peel strength (peel strength after HAST test) was measured.

<Test 4. Measurement of surface roughness Ra and Rz>
The arithmetic mean roughness Ra and maximum height Rz defined in the Japanese Industrial Standards (JIS B0601-2001) were measured for the surface of the insulating layer of sample substrate A (sample substrate A after silane coupling treatment and before heat treatment) obtained in the above test 3. The measurements were performed using a non-contact surface roughness meter (WYKO NT3300 manufactured by B-CO Instruments) in VSI mode with a 50x lens, with a measurement range of 121 μm × 92 μm.

<Test 5. Measurement of crosslink density n>
A polyimide film ("Kapton 200EN" manufactured by Toray DuPont Co., Ltd.) was prepared as a polyimide substrate. The protective film was peeled off from the resin sheet produced in the Examples and Comparative Examples. This resin sheet was laminated onto one side of the polyimide substrate using a batch-type vacuum pressure laminator ("MVLP-500" manufactured by Meiki Seisakusho Co., Ltd.) so that the resin composition layer was in contact with the polyimide substrate. The lamination was performed by reducing the pressure for 30 seconds to a pressure of 13 hPa or less, and then laminating at 100°C and a pressure of 0.74 MPa for 30 seconds. A resin sheet with a polyimide substrate was obtained by the above lamination.

The resin sheet with polyimide substrate was placed on a 12-inch silicon wafer with the polyimide substrate side in contact with the silicon wafer. The four sides of the resin sheet with polyimide substrate were attached to the silicon wafer with polyimide tape. The resin composition layer was thermally cured by heating at 100°C for 30 minutes and then at 170°C for 30 minutes to form an insulating layer as a cured body. The support was then peeled off to obtain an intermediate laminate having a configuration of insulating layer/polyimide substrate/silicon wafer.

The surface of the insulating layer revealed by peeling off the support was irradiated with ultraviolet light having a wavelength of 172 nm at 25°C for 10 seconds.

A silane coupling agent solution (silane coupling agent concentration 5 g/L, glycol solvent concentration 350 g/L) was prepared by dissolving a silane coupling agent (Shin-Etsu Chemical Co., Ltd. "KBM903", 3-amino-propyltrimethoxysilane) and a glycol solvent (diethylene glycol-mono-n-butyl ether) in water. The pH of the solution was 5.0. The intermediate laminate was immersed in this silane coupling agent solution for 10 minutes at 40°C. The intermediate laminate was then dried at 60°C for 10 minutes and further heat-treated at 180°C for 60 minutes to obtain sample substrate C.

After the heat treatment, the insulating layer was peeled off from sample substrate C to obtain a cured body. This cured body was cut into a width of 5 mm and a length of 15 mm to obtain test piece D. For test piece D, a thermomechanical analysis was performed by the tensile load method using a viscoelasticity measuring device ("DMA7100" manufactured by Hitachi High-Tech Science Corporation). Specifically, after test piece C was mounted on the thermomechanical analyzer, the storage modulus and loss modulus were measured under the measurement conditions of a load of 200 mN and a heating rate of 5°C/min.

The glass transition temperature Tg (° C.) was obtained from the peak top of tan δ (temperature dependence curve of the ratio of storage modulus and loss modulus) obtained as a measurement result.
Next, a predetermined temperature T(K) that is 80K higher than the glass transition temperature Tg was determined. Specifically, 273K was added to convert the obtained glass transition temperature Tg(°C) into the unit K, and then 80K was added to determine the predetermined temperature T(K). Since the value of the storage modulus tends not to vary significantly in a temperature region near the predetermined temperature T(K), it is acceptable that an error may occur within a range of -5°C to +5°C for the determined predetermined temperature T(K). Then, a measured value E' (unit: GPa, i.e., ×10 ⁹ Pa) of the storage modulus at the determined predetermined temperature T(K) was obtained.

The obtained storage modulus E' (Pa) was substituted into the following formula (M1) to calculate the crosslink density n (mol/cm ³ ). Here, the crosslink density n can be considered as an index showing the number of crosslinked molecules present per unit volume.
n = E' / 3RT (M1)
(In the above formula (M1), T represents a predetermined temperature T (K); E' represents a measured value (Pa) of the storage modulus at the predetermined temperature T (K); and R represents a gas constant of 8,310,000 (Pa·cm ³ /mol·K). Note that the measured value (10 ⁹ Pa) of the shear modulus G' at the predetermined temperature T (K) may also be used as E'/3.)

<Test 6. Measurement of dielectric tangent>
A cured body was obtained by peeling off the insulating layer from the sample substrate C obtained in the above test 5. The dielectric loss tangent Df of this cured body was measured by a cavity resonance perturbation method using an "HP8362B" manufactured by Agilent Technologies at a measurement frequency of 5.8 GHz and a measurement temperature of 23° C. Measurements were performed on three test pieces, and the average value was calculated.

<Test 7. Measurement of storage modulus and glass transition temperature>
The insulating layer was peeled off from the sample substrate C obtained in the above test 5 to obtain a cured body. This cured body was cut to obtain a test piece with a width of 7 mm and a length of 40 mm. This test piece was subjected to dynamic mechanical analysis in a tensile mode using a dynamic mechanical analyzer (Seiko Instruments Inc.'s "DMS-6100"). Specifically, after mounting the test piece on the device, it was measured under the measurement conditions of a frequency of 1 Hz and a temperature rise rate of 5°C/min. In this measurement, the storage modulus (E') at 25°C was read. In addition, the temperature at which tan δ was maximum was read as the glass transition temperature Tg.

<Results>
The results of the above-mentioned Examples and Comparative Examples are shown in the following table. In the following table, the amount of each component is expressed as parts by mass of non-volatile components. The meanings of the abbreviations are as follows.
Ra: arithmetic mean roughness.
Rz: maximum height.
Tg: glass transition temperature.
Peel strength before HAST: The peel strength between the insulating layer and the conductor layer before HAST testing.
Peel strength after HAST: The peel strength between the insulating layer and the conductor layer after HAST testing.

<Consideration>
In Comparative Example 1, the surface roughness of the cured body was large, and therefore high adhesion was not obtained. In Comparative Example 2, high adhesion was obtained before the HAST test, but the conductor layer swelled due to the HAST test, and the peel strength after the HAST test could not be measured. In Comparative Example 2, the nitrogen atom concentration on the surface of the cured sample layer was high, so it is presumed that the nitrogen atom concentration on the surface of the insulating layer was also high, and therefore the water absorption increased, causing the swelling. Furthermore, in Comparative Example 3, high adhesion was not obtained before the HAST test. In Comparative Example 3, the contact angle X on the surface of the cured sample layer was large, so it is presumed that the compatibility between the treatment liquid of the silane coupling agent treatment and the insulating layer was low, and therefore the effect of improving adhesion was not sufficiently obtained.

In contrast, in all of the examples, high adhesion was achieved after the HAST test. The results of these examples confirm that the present invention can achieve high adhesion after the HAST test.

REFERENCE SIGNS LIST 100 Semiconductor chip package 110 Semiconductor chip 120 Sealing layer 130 Rewiring formation layer 140 Rewiring layer 150 Solder resist layer 160 Bump

Claims (18)

A cured product of a resin composition containing a thermosetting resin;
The cured body has a surface with an arithmetic mean roughness Ra of less than 100 nm;
When a test was conducted in which a layer of the resin composition was cured at 200° C. for 90 minutes to form a cured sample layer,
the contact angle of diethylene glycol-mono-n-butyl ether with the surface of the cured sample layer is less than 30°;
A cured body, in which the nitrogen atomic concentration obtained based on the peak area of the N1s spectrum in X-ray photoelectron spectroscopy of the surface of the cured sample layer is less than 3.8 atomic %. The hardened body according to claim 1, in which the nitrogen atom concentration obtained based on the peak area of the N1s spectrum in X-ray photoelectron spectroscopy of the surface of the hardened sample layer is 0.1 atomic % or more. The cured product according to claim 1, wherein the resin composition contains an inorganic filler. The cured product according to claim 3, wherein the amount of inorganic filler in the resin composition is 40% by mass or more and 90% by mass or less relative to 100% by mass of the non-volatile components of the resin composition. The hardened body according to claim 1, wherein the thermosetting resin comprises an epoxy resin. The hardened body according to claim 1, wherein the thermosetting resin comprises a phenolic resin. The hardened body according to claim 1, wherein the thermosetting resin comprises an active ester resin. The cured product according to claim 1, wherein the thermosetting resin comprises a maleimide resin. The cured product according to claim 1, wherein the resin composition contains a curing accelerator. The cured product according to claim 1, wherein the resin composition contains a resin component containing a nitrogen atom. The hardened body according to claim 1, for forming a conductor layer on the surface having an arithmetic mean roughness Ra of less than 100 nm. A circuit board comprising an insulating layer formed from the cured body according to any one of claims 1 to 11. A semiconductor chip package comprising the cured body according to any one of claims 1 to 11 and a semiconductor chip. A semiconductor device comprising the circuit board according to claim 12. A semiconductor device comprising the semiconductor chip package according to claim 13. A method for producing the cured body according to any one of claims 1 to 11, comprising the steps of:
A step of curing a resin composition containing a thermosetting resin to obtain a cured body;
A step of subjecting the cured body to an ultraviolet treatment;
and treating the cured body with a silane coupling agent. A resin sheet comprising a support and a layer of a resin composition formed on the support;
The resin composition comprises a thermosetting resin;
When a first test is performed in which a layer of the resin composition is cured to form a sample cured body and the surface of the sample cured body facing the support is subjected to an ultraviolet treatment and a silane coupling agent treatment, the arithmetic mean roughness Ra of the surface facing the support is less than 100 nm;
When a second test was performed in which the layer of the resin composition was cured at 200° C. for 90 minutes to form a cured sample layer,
the contact angle of diethylene glycol-mono-n-butyl ether with the support side surface of the cured sample layer is less than 30°;
A resin sheet in which the nitrogen atom concentration obtained based on the peak area of the N1s spectrum in X-ray photoelectron spectroscopy of the support side surface of the cured sample layer is less than 3.8 atomic %. In the first test, the layer of the resin composition was cured at 170° C. for 30 minutes.
In the first test, the ultraviolet treatment was performed by irradiating the sample cured body with ultraviolet light having a wavelength of 172 nm for 10 seconds,
18. The resin sheet according to claim 17, wherein in the first test, the silane coupling agent treatment is performed by immersing the sample cured body in an aqueous solution containing 5 g/L of 3-amino-propyltrimethoxysilane and 350 g/L of diethylene glycol-mono-n-butyl ether at 40°C for 10 minutes.

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