JP6198038B2 - Curable composition, cured product, and printed wiring board - Google Patents

Description

  The present invention relates to a curable composition in which the obtained cured product is excellent in moisture resistance and solder resistance, a cured product obtained by curing the composition, and a printed wiring board.

  A composition comprising an epoxy group-containing compound and its curing agent is widely used as an insulating material for semiconductor encapsulants and printed wiring boards because the cured product is excellent in heat resistance and moisture resistance.

  Among these, for printed wiring board applications, with the trend toward miniaturization and high performance of electronic equipment, it is required to realize high-density wiring by narrowing the wiring pitch, and as a semiconductor mounting method corresponding to this, Instead of the conventional wire bonding method, a flip chip connection method in which a semiconductor device and a wiring board are joined by solder balls has become the mainstream. In this flip-chip connection method, solder balls are placed between the wiring board and the semiconductor, and the whole is heated to reflow and join the solder. Various performances such as reduction, minimization of thermal expansion coefficient, high moisture resistance and solder resistance are required.

  As a material excellent in heat resistance, for example, a composition of a cyanate ester compound such as bis (3,5-dimethyl-4-cyanatephenyl) methane and a naphthol novolac type epoxy resin is known (see Patent Document 1). . Such a composition is superior in heat resistance when compared with an insulating material using a conventional phenol novolac type epoxy resin, but has sufficient resistance to moisture and solder because the toughness of the cured product is low. It was not something.

Japanese Patent Application Laid-Open No. 9-100393

  Therefore, the problem to be solved by the present invention is to provide a curable composition in which the obtained cured product is excellent in moisture resistance and solder resistance, a cured product obtained by curing this, and a printed wiring board.

  The present inventors have found that a cured product having excellent moisture and solder resistance can be obtained by using an epoxy resin having a specific trifunctional epoxy compound as an essential component and using a cyanate ester compound as a curing agent. The headline and the present invention were completed.

  That is, the present invention provides the following structural formula (1)

（式中、Ｒ^１及びＲ^２は、それぞれ独立して水素原子、炭素原子数１〜４のアルキル基、炭素原子数１〜４のアルコキシ基を、Ｇはグリシジル基を表す。）
で表される分子構造を有する３官能エポキシ化合物（Ａ１）と、シアン酸エステル化合物（Ｂ）とを含有することを特徴とする硬化性組成物に関する。

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and G represents a glycidyl group.)
The curable composition characterized by containing the trifunctional epoxy compound (A1) which has the molecular structure represented by these, and a cyanate ester compound (B).

  The present invention further relates to a cured product obtained by curing the curable composition.

  The present invention further relates to a printed wiring board obtained by impregnating a reinforcing base material with a varnish composition obtained by further blending an organic solvent with the curable composition, and stacking a copper foil and heat-pressing it.

  ADVANTAGE OF THE INVENTION According to this invention, the hardened | cured material obtained can be provided with the curable composition which is excellent in moisture-proof solder resistance, the hardened | cured material formed by hardening this, and a printed wiring board.

FIG. 1 is a GPC chart of the cresol-naphthol resin (a-1) obtained in Production Example 1. FIG. 2 is a GPC chart of the epoxy resin (A-1) obtained in Production Example 1. FIG. 3 is a ¹³ C-NMR chart of the epoxy resin (A-1) obtained in Production Example 1. FIG. 4 is an MS spectrum of the epoxy resin (A-1) obtained in Production Example 1. FIG. 5 is a GPC chart of the cresol-naphthol resin (a-2) obtained in Production Example 2. FIG. 6 is a GPC chart of the epoxy resin (A-2) obtained in Production Example 2. FIG. 7 is a ¹³ C-NMR chart of the epoxy resin (A-2) obtained in Production Example 2. FIG. 8 is an MS spectrum of the epoxy resin (A-2) obtained in Production Example 2.

Hereinafter, the present invention will be described in detail.
The trifunctional epoxy compound (A1) used as the main agent in the curable composition of the present invention has the following structural formula (1).

（式中、Ｒ^１及びＲ^２は、それぞれ独立して水素原子、炭素原子数１〜４のアルキル基、炭素原子数１〜４のアルコキシ基を、Ｇはグリシジル基を表す。）
で表される分子構造を有するものである。

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and G represents a glycidyl group.)
It has the molecular structure represented by these.

  Such a trifunctional epoxy compound (A1) is, for example, an epoxy resin obtained by polyglycidyl etherification of a reaction product of cresol, β-naphthol compound, and formaldehyde, and includes various resin structures. What is obtained as one component in a mixture is mentioned. Since the trifunctional epoxy compound (A1) has an excellent balance between the epoxy group concentration and the aromatic ring concentration in the molecular structure, the curable composition containing the trifunctional epoxy compound has a high reactivity and a high crosslinking density. A cured product having low properties and excellent moisture and solder resistance can be obtained.

  Although the cyanate ester compound used as a curing agent in the present invention has a characteristic that the cured product is hard and excellent in heat resistance, it is insufficient in toughness, so that it is likely to be cracked or swollen in the moisture and solder resistance test. On the other hand, the epoxy resin having the trifunctional epoxy compound (A1) used as a main component in the present invention as an essential component has a high molecular unit orientation and thus has a low hygroscopicity under wet heat conditions. Since it is excellent also in toughness, the hardened | cured material which is excellent in moisture-proof solder resistance can be obtained by using it in combination with a cyanate ester compound.

  Specifically, the trifunctional epoxy compound (A1) has the following structural formulas (1-1) to (1-6).

で表される化合物が挙げられる。これらのなかでも特に前記構造式１−１で表されるもの、即ち、前記構造式（１）におけるＲ^１及びＲ^２が全て水素原子であるものが、硬化物における熱膨張係数が小さく耐湿耐半田性に優れる硬化物が得られることから好ましい。

The compound represented by these is mentioned. Among these, particularly those represented by the structural formula 1-1, that is, those in which R ¹ and R ² in the structural formula (1) are all hydrogen atoms, the cured product has a small coefficient of thermal expansion and is resistant to moisture and resistance. This is preferable because a cured product having excellent solderability can be obtained.

  The epoxy resin used in the present invention has the following structural formula (2) in addition to the trifunctional epoxy compound (A1).

（式中、Ｒ^１及びＲ^２は、それぞれ独立して水素原子、炭素原子数１〜４のアルキル基、炭素原子数１〜４のアルコキシ基を、Ｇはグリシジル基を表す。）
で表される２量体エポキシ化合物（Ａ２）を含有していても良く、硬化物における吸湿性が低下することから、前記２量体エポキシ化合物（Ａ２）を含有することが好ましい。

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and G represents a glycidyl group.)
It may contain the dimer epoxy compound (A2) represented by these, Since the hygroscopic property in hardened | cured material falls, it is preferable to contain the said dimer epoxy compound (A2).

  Specifically, the dimer epoxy compound (A2) is represented by the following structural formulas (2-1) to (2-6).

で表される化合物が挙げられる。これらのなかでも特に前記構造式２−１で表されるもの、即ち、前記構造式（２）におけるＲ^１及びＲ^２が、全て水素原子であるものが、硬化物における熱膨張係数が小さく耐湿耐半田性に優れる硬化物が得られることから好ましい。

The compound represented by these is mentioned. Among these, particularly those represented by the structural formula 2-1, that is, those in which R ¹ and R ² in the structural formula (2) are all hydrogen atoms, the cured product has a small coefficient of thermal expansion and is moisture resistant. This is preferable because a cured product having excellent solder resistance can be obtained.

  The epoxy resin used in the present invention has the following structural formula (3) in addition to the trifunctional epoxy compound (A1).

（式中、Ｒ^１及びＲ^２は、それぞれ独立して水素原子、炭素原子数１〜４のアルキル基、炭素原子数１〜４のアルコキシ基を、Ｇはグリシジル基を表す。）
で表される４官能エポキシ化合物（Ａ３）を含有しても良い。該４官能エポキシ化合物（Ａ３）は特に官能基濃度が高く、その反応性も非常に高いことから、これを含有することにより硬化物がより高密に架橋されたものとなり、硬化物の耐熱性がより一層顕著なものとなることから好ましい。

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and G represents a glycidyl group.)
A tetrafunctional epoxy compound (A3) represented by Since the tetrafunctional epoxy compound (A3) has a particularly high functional group concentration and very high reactivity, the inclusion of the tetrafunctional epoxy compound (A3) results in the cured product being more densely cross-linked, and the heat resistance of the cured product is improved. It is preferable because it becomes even more prominent.

  Specifically, such a tetrafunctional epoxy compound (A3) has the following structural formulas (3-1) to (3-6).

で表される化合物が挙げられる。これらのなかでも特に前記構造式（３−１）で表されるもの、即ち、前記構造式（３）におけるＲ^１及びＲ^２が、全て水素原子であるものが、硬化物における熱膨張係数が小さくなり、耐湿耐半田性に優れるものとなることから好ましい。

The compound represented by these is mentioned. Among these, in particular, those represented by the structural formula (3-1), that is, those in which R ¹ and R ² in the structural formula (3) are all hydrogen atoms have a coefficient of thermal expansion in the cured product. It is preferable because it becomes small and has excellent moisture and solder resistance.

  Furthermore, the epoxy resin used in the present invention includes the following structural formula (4) in addition to the trifunctional epoxy compound (A1).

（式中、Ｒ^１及びＲ^２は、それぞれ独立して水素原子、炭素原子数１〜４のアルキル基、炭素原子数１〜４のアルコキシ基を、Ｇはグリシジル基を表し、ｎは繰り返し単位を表す３以上の整数である。）
においてｎが３以上であるその他の多官能エポキシ化合物（Ａ４）を含有していても良い。

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, G represents a glycidyl group, and n represents a repeating unit. Represents an integer of 3 or more.)
In addition, other polyfunctional epoxy compounds (A4) in which n is 3 or more may be contained.

  As described above, the trifunctional epoxy compound (A1) is, for example, an epoxy resin obtained by polyglycidyl etherification of a reaction product of cresol, β-naphthol compound, and formaldehyde, and has various resin structures. What is obtained as one component in the mixture contained is mentioned. The cresol used here may be any of ortho-cresol, para-cresol, and meta-cresol, or a mixture thereof. Among these, orthocresol, paracresol, or a combination of orthocresol and paracresol is preferable because the trifunctional epoxy compound (A1) is efficiently generated.

  When the polyglycidyl ether of the reaction product of paracresol, β-naphthol compound, and formaldehyde is used as the epoxy resin containing the trifunctional epoxy compound (A1), the trifunctional epoxy compound (A1) contained in the epoxy resin is used. ) Is the following structural formula (1-1)

（式中、Ｒ^１及びＲ^２は、それぞれ独立して水素原子、炭素原子数１〜４のアルキル基、炭素原子数１〜４のアルコキシ基を、Ｇはグリシジル基を表す。）
で表される３官能エポキシ化合物（Ａ１−１）となる。本発明で用いるエポキシ樹脂は前記３官能エポキシ化合物（Ａ１）以外のエポキシ化合物を含有していても良く、前記３官能エポキシ化合物（Ａ１−１）を必須の成分とする場合には、熱膨張率が低く耐湿耐半田性に優れる硬化物が得られることから、エポキシ樹脂中における前記３官能エポキシ化合物（Ａ１−１）の含有率が、ＧＰＣ測定における面積比率で５５％以上であることが好ましく、７０〜９８％の範囲であることがより好ましく、８０〜９５％の範囲であることが特に好ましい。

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and G represents a glycidyl group.)
It becomes a trifunctional epoxy compound (A1-1) represented by these. The epoxy resin used in the present invention may contain an epoxy compound other than the trifunctional epoxy compound (A1), and when the trifunctional epoxy compound (A1-1) is an essential component, the coefficient of thermal expansion. Therefore, it is preferable that the content of the trifunctional epoxy compound (A1-1) in the epoxy resin is 55% or more in terms of an area ratio in GPC measurement because a cured product having low moisture resistance and solder resistance is obtained. A range of 70 to 98% is more preferable, and a range of 80 to 95% is particularly preferable.

  Further, as described above, the epoxy resin used in the present invention may contain the dimer epoxy compound (A2), and the cured product has excellent moisture absorption resistance. The content ratio of the body epoxy compound (A2) is preferably in the range of 2 to 25%, more preferably in the range of 3 to 20% in terms of area ratio in GPC measurement. That is, when the curable composition of the present invention is an essential component of the trifunctional epoxy compound (A1-1), the content ratio of the trifunctional epoxy compound (A1-1) in the epoxy resin used is an area ratio in GPC. And the content of the dimer epoxy compound (A2) is preferably in the range of 2 to 25% in terms of area ratio in GPC.

  Moreover, since the hardened | cured material which is lower in a coefficient of thermal expansion and excellent in moisture resistance and solder resistance is obtained, the total content of the trifunctional epoxy compound (A1-1) and the dimer compound (A2) in the epoxy resin is obtained. The rate is preferably 60% or more, more preferably 65% or more in terms of the area ratio in GPC measurement.

Here, the content of the trifunctional epoxy compound (A1), the dimer compound (A2), the tetrafunctional epoxy compound (A3), and the other polyfunctional epoxy compound (A4) in the epoxy resin used in the present invention. The rate is the ratio of the peak area of each structure to the peak area of the entire epoxy resin calculated by GPC measurement under the following conditions.
<GPC measurement conditions>
Measuring device: “HLC-8220 GPC” manufactured by Tosoh Corporation
Column: Guard column “HXL-L” manufactured by Tosoh Corporation
+ "TSK-GEL G2000HXL" manufactured by Tosoh Corporation
+ "TSK-GEL G2000HXL" manufactured by Tosoh Corporation
+ Tosoh Corporation “TSK-GEL G3000HXL”
+ Tosoh Corporation “TSK-GEL G4000HXL”
Detector: RI (differential refractometer)
Data processing: “GPC-8020 Model II version 4.10” manufactured by Tosoh Corporation
Measurement conditions: Column temperature 40 ° C
Developing solvent Tetrahydrofuran
Flow rate: 1.0 ml / min Standard: The following monodisperse polystyrene having a known molecular weight was used in accordance with the measurement manual of “GPC-8020 Model II version 4.10”.
(Polystyrene used)
“A-500” manufactured by Tosoh Corporation
"A-1000" manufactured by Tosoh Corporation
"A-2500" manufactured by Tosoh Corporation
"A-5000" manufactured by Tosoh Corporation
“F-1” manufactured by Tosoh Corporation
"F-2" manufactured by Tosoh Corporation
“F-4” manufactured by Tosoh Corporation
“F-10” manufactured by Tosoh Corporation
“F-20” manufactured by Tosoh Corporation
“F-40” manufactured by Tosoh Corporation
“F-80” manufactured by Tosoh Corporation
“F-128” manufactured by Tosoh Corporation
Sample: A 1.0 mass% tetrahydrofuran solution filtered in terms of resin solids and filtered through a microfilter (50 μl).

  As an epoxy resin containing the trifunctional epoxy compound (A1), when polyglycidyl ether of a reaction product of paracresol, β-naphthol compound, and formaldehyde is used, the resulting epoxy resin has excellent solvent solubility. The softening point is preferably in the range of 80 to 140 ° C, and more preferably in the range of 85 to 135 ° C because it is excellent in low thermal expansion in the cured product in addition to solvent solubility.

  The epoxy equivalent of the epoxy resin is preferably in the range of 220 to 260 g / eq, and more preferably in the range of 225 to 255 g / eq, because the low thermal expansion property of the cured product is improved. On the other hand, the value of the molecular weight distribution (Mw / Mn) is preferably in the range of 1.00 to 1.50 since the change in heat resistance after the heat history in the cured product becomes small. In addition, in this invention, molecular weight distribution (Mw / Mn) is the weight average molecular weight (Mw) of the epoxy resin measured on the same conditions as the GPC measurement conditions at the time of calculating | requiring the content rate of each component in the above-mentioned epoxy resin. It is a value calculated from the value and the value of the number average molecular weight (Mn).

  When the polyglycidyl ether of the reaction product of orthocresol, β-naphthol compound, and formaldehyde is used as the epoxy resin containing the trifunctional epoxy compound (A1), the trifunctional epoxy compound (A1) contained in the epoxy resin is used. ) Is the following structural formula (1-2)

（式中、Ｒ^１及びＲ^２は、それぞれ独立して水素原子、炭素原子数１〜４のアルキル基、炭素原子数１〜４のアルコキシ基を、Ｇはグリシジル基を表す。）
で表される３官能エポキシ化合物（Ａ１−２）となる。本発明で用いるエポキシ樹脂は前記３官能エポキシ化合物（Ａ１）以外のエポキシ化合物を含有していても良く、前記３官能エポキシ化合物（Ａ１−２）を必須の成分とする場合には、熱膨張率がより低く耐湿耐半田性に優れる硬化物が得られることから、エポキシ樹脂中における前記３官能エポキシ化合物（Ａ１−２）の含有率が、ＧＰＣ測定における面積比率で２５％以上であることが好ましく、２５〜７０％の範囲であることがより好ましく、３０〜６０％の範囲であることが特に好ましい。

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and G represents a glycidyl group.)
It becomes a trifunctional epoxy compound (A1-2) represented by these. The epoxy resin used in the present invention may contain an epoxy compound other than the trifunctional epoxy compound (A1), and when the trifunctional epoxy compound (A1-2) is an essential component, the coefficient of thermal expansion. Therefore, it is preferable that the content of the trifunctional epoxy compound (A1-2) in the epoxy resin is 25% or more by area ratio in GPC measurement because a cured product having lower moisture resistance and solder resistance can be obtained. A range of 25 to 70% is more preferable, and a range of 30 to 60% is particularly preferable.

  As described above, the epoxy resin used in the present invention may contain the dimer compound (A2), and is excellent in moisture absorption resistance in the cured product, so that the dimer compound (A2) in the epoxy resin is The content is preferably in the range of 2 to 25% by area ratio in GPC measurement, and more preferably in the range of 3 to 20%.

  In the case where the curable composition of the present invention contains the trifunctional epoxy compound (A1-2) as an essential component, the following structural formula (3-2)

（式中、Ｒ^１及びＲ^２は、それぞれ独立して水素原子、炭素原子数１〜４のアルキル基、炭素原子数１〜４のアルコキシ基を、Ｇはグリシジル基を表す。）
で表される４官能エポキシ化合物（Ａ３−２）を含有することが好ましく、エポキシ樹脂中の含有率は、耐熱性に優れる硬化物が得られることから、ＧＰＣ測定における面積比率で１０〜４０％の範囲であることが好ましく、１０〜３０％の範囲であることがより好ましい。

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and G represents a glycidyl group.)
It is preferable to contain the tetrafunctional epoxy compound (A3-2) represented by this, and since the hardened | cured material which is excellent in heat resistance is obtained, the content rate in an epoxy resin is 10 to 40% by the area ratio in GPC measurement. Is preferably in the range of 10 to 30%.

  When the curable composition of the present invention contains the trifunctional epoxy compound (A1-2), the dimer compound (A2), and the tetrafunctional epoxy compound (A3-2), these in the epoxy resin to be used The total content of is preferably 65% or more in terms of area ratio in GPC measurement, more preferably 70% or more, since a cured product having a low coefficient of thermal expansion and excellent moisture resistance and solder resistance can be obtained. .

  When the curable composition of the present invention contains the trifunctional epoxy compound (A1-2) as an essential component, the following structural formula (4-2)

（式中、Ｒ^１及びＲ^２は、それぞれ独立して水素原子、炭素原子数１〜４のアルキル基、炭素原子数１〜４のアルコキシ基を、Ｇはグリシジル基を表し、ｎは繰り返し単位を表す３以上の整数である。）
で表されるその他の多官能エポキシ化合物（Ａ４−２）を含有していても良く、その場合、硬化物における耐湿耐半田性に優れるという本願発明の硬化が十分に発揮されることから、エポキシ樹脂中の前記３官能エポキシ化合物（Ａ１−２）、前記２量体化合物（Ａ２）、及び前記４官能化合物（Ａ３−２）の合計の含有率がＧＰＣ測定における面積比率で６５％以上であり、かつ、前記３官能エポキシ化合物（Ａ１−２）、前記２量体化合物（Ａ２）、前記４官能化合物（Ａ３−２）及び前記多官能化合物（Ａ４−２）においてｎが３〜５の何れかである化合物の合計の含有率が８５％以上であることが好ましい。

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, G represents a glycidyl group, and n represents a repeating unit. Represents an integer of 3 or more.)
The polyfunctional epoxy compound (A4-2) represented by the formula (A4-2) may be contained, and in that case, the curing of the present invention that is excellent in moisture resistance and solder resistance in the cured product is sufficiently exhibited. The total content of the trifunctional epoxy compound (A1-2), the dimer compound (A2), and the tetrafunctional compound (A3-2) in the resin is 65% or more in terms of area ratio in GPC measurement. In the trifunctional epoxy compound (A1-2), the dimer compound (A2), the tetrafunctional compound (A3-2), and the polyfunctional compound (A4-2), any one of n is 3 to 5 It is preferable that the total content of these compounds is 85% or more.

  As an epoxy resin containing the trifunctional epoxy compound (A1), when polyglycidyl ether of a reaction product of orthocresol, β-naphthol compound, and formaldehyde is used, it becomes an epoxy resin excellent in solvent solubility. The softening point is preferably in the range of 70 to 100 ° C, and more preferably in the range of 75 to 90 ° C because it is excellent in low thermal expansion in the cured product in addition to solvent solubility.

  Moreover, the epoxy equivalent of the epoxy resin is preferably in the range of 220 to 300 g / eq because the low thermal expansion property of the cured product becomes good. On the other hand, the value of the molecular weight distribution (Mw / Mn) is preferably in the range of 1.00 to 1.50 since the change in heat resistance after the heat history in the cured product becomes small.

As described above, the trifunctional epoxy compound (A1) essential for the curable composition of the present invention is, for example, an epoxy resin obtained by polyglycidyl etherification of a reaction product of cresol, β-naphthol compound, and formaldehyde. What is obtained as one component is mentioned, Specifically, it can manufacture by the following method 1 or method 2.
Method 1: A β-naphthol compound and formaldehyde are reacted in the presence of an organic solvent and an alkali catalyst, and then cresol is added and reacted in the presence of formaldehyde to obtain a cresol-naphthol resin (step 1). A method in which an epihalohydrin is reacted with the obtained cresol-naphthol resin (step 2) to obtain a target epoxy resin.
Method 2: Cresole, β-naphthol compound, and formaldehyde are reacted in the presence of an organic solvent and an alkali catalyst to obtain a cresol-naphthol resin (step 1), and then the resulting cresol-naphthol resin is reacted with an epihalohydrin. (Step 2) to obtain the target epoxy resin.

  In the present invention, the trifunctional epoxy compound (A1) or 2 can be obtained by using an alkali catalyst as a reaction catalyst in Step 1 of Method 1 or 2, and using an organic solvent in a small amount relative to the raw material components. The proportion of the monomer compound (A2), the tetrafunctional epoxy compound (A3), and the other polyfunctional epoxy compound (A4) in the epoxy resin can be adjusted to a desired range.

  Examples of the alkali catalyst used herein include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, inorganic alkalis such as metal sodium, metal lithium, sodium hydride, sodium carbonate, and potassium carbonate. The amount used is preferably in the range of 0.01 to 2.0 times the molar amount relative to the total number of phenolic hydroxyl groups of the cresol and β-naphthol compounds as raw material components.

  Examples of the organic solvent include methyl cellosolve, isopropyl alcohol, ethyl cellosolve, toluene, xylene, and methyl isobutyl ketone. Among these, isopropyl alcohol is preferable because generation of a trifunctional phenol compound serving as a precursor of the trifunctional epoxy compound (A1) is promoted. The amount of the organic solvent used in the present invention is in the range of 5 to 70 parts by mass per 100 parts by mass of the total mass of the cresol and β-naphthol compounds that are the raw material components, and the trifunctional epoxy compound (A1) and 2 quantities. The body compound (A2), the tetrafunctional epoxy compound (A3), and other polyfunctional epoxy compounds (A4) are preferable because the abundance ratio in the epoxy resin is easily adjusted to a desired range.

  The β-naphthol compounds used in the present invention include β-naphthol and compounds in which an alkyl group such as a methyl group, an ethyl group, a propyl group, or a t-butyl group, and an alkoxy group such as a methoxy group or an ethoxy group are substituted by a nucleus. Can be mentioned. Among these, β-naphthol having no substituent is preferable because heat resistance in a cured product of the finally obtained curable composition is improved.

  On the other hand, the formaldehyde used here may be a formalin solution in an aqueous solution state or paraformaldehyde in a solid state.

  The use ratio of cresol and β-naphthol compound in step 1 of method 1 or method 2 is such that the molar ratio (cresol / β-naphthol compound) is [1 / 0.5] to [1/4]. It is preferable that the ratio of each component in the epoxy resin obtained can be easily adjusted.

  The reaction charge ratio of formaldehyde is a ratio of 0.6 to 2.0 times the amount of formaldehyde on a molar basis with respect to the total number of moles of cresol and β-naphthol compound, in particular, excellent heat resistance Therefore, the ratio is preferably 0.6 to 1.5 times the amount.

  In step 1 of Method 1, a reaction vessel is charged with a predetermined amount of β-naphthol compound, formaldehyde, an organic solvent, and an alkali catalyst, reacted at 40 to 100 ° C., and after completion of the reaction, cresol (if necessary) Further, formaldehyde) is added and reacted under a temperature condition of 40 to 100 ° C., whereby a cresol-naphthol resin as a precursor can be obtained.

  After completion of the reaction in Step 1, the reaction mixture is neutralized or washed with water until the pH value of the reaction mixture becomes 4-7. The neutralization treatment and the water washing treatment may be performed according to conventional methods. For example, acidic substances such as acetic acid, phosphoric acid, and sodium phosphate can be used as the neutralizing agent. After the neutralization or water washing treatment, the organic solvent is distilled off under heating under reduced pressure to obtain a precursor cresol-naphthol resin.

  In Step 1 of Method 2, a predetermined amount of β-naphthol compound, cresol, formaldehyde, an organic solvent, and an alkali catalyst are charged into a reaction vessel and reacted at 40 to 100 ° C., thereby being a precursor cresol- A naphthol resin (A) can be obtained.

  After completion of the reaction in Step 1, the reaction mixture is neutralized or washed with water until the pH value of the reaction mixture becomes 4-7. The neutralization treatment and the water washing treatment may be performed according to conventional methods. For example, acidic substances such as acetic acid, phosphoric acid, and sodium phosphate can be used as the neutralizing agent. After the neutralization or water washing treatment, the organic solvent is distilled off under reduced pressure heating to obtain the precursor cresol-naphthol resin (A).

  Next, Step 2 of Method 1 or Method 2 is a step of producing the desired epoxy resin by reacting the polycondensate obtained in Step 1 with epihalohydrin. Specifically, in the step 2, epihalohydrin is added in a ratio of 2 to 10 times (molar basis) with respect to the number of moles of the phenolic hydroxyl group in the polycondensate, and further the mole of the phenolic hydroxyl group. A method of reacting at a temperature of 20 to 120 ° C. for 0.5 to 10 hours while adding or gradually adding 0.9 to 2.0 times (molar basis) of the basic catalyst to the number is mentioned. The basic catalyst may be solid or an aqueous solution thereof. When an aqueous solution is used, it is continuously added and water and epihalohydrins are continuously distilled from the reaction mixture under reduced pressure or normal pressure. Alternatively, the solution may be separated and further separated to remove water and the epihalohydrin is continuously returned to the reaction mixture.

  In the first batch of epoxy resin production, all of the epihalohydrins used for preparation are new in industrial production, but the subsequent batches are consumed by the reaction with epihalohydrins recovered from the crude reaction product. It is preferable to use in combination with new epihalohydrins corresponding to the amount disappeared. At this time, the epihalohydrin used is not particularly limited, and examples thereof include epichlorohydrin, epibromohydrin, β-methylepichlorohydrin, and the like. Of these, epichlorohydrin is preferred because it is easily available industrially.

  Specific examples of the basic catalyst include alkaline earth metal hydroxides, alkali metal carbonates, and alkali metal hydroxides. In particular, alkali metal hydroxides are preferable from the viewpoint of excellent catalytic activity of the epoxy resin synthesis reaction, and examples thereof include sodium hydroxide and potassium hydroxide. In use, these basic catalysts may be used in the form of an aqueous solution of about 10 to 55% by mass, or in the form of a solid. Moreover, the reaction rate in the synthesis | combination of an epoxy resin can be raised by using an organic solvent together. Examples of such organic solvents include, but are not limited to, ketones such as acetone and methyl ethyl ketone, alcohol compounds such as methanol, ethanol, 1-propyl alcohol, isopropyl alcohol, 1-butanol, secondary butanol, and tertiary butanol, methyl Examples thereof include cellosolves such as cellosolve and ethyl cellosolve, ether compounds such as tetrahydrofuran, 1,4-dioxane, 1,3-dioxane and diethoxyethane, and aprotic polar solvents such as acetonitrile, dimethyl sulfoxide and dimethylformamide. These organic solvents may be used alone or in combination of two or more kinds in order to adjust the polarity.

  After the reaction product of the epoxidation reaction is washed with water, unreacted epihalohydrin and the organic solvent to be used in combination are distilled off by distillation under heating and reduced pressure. Further, in order to obtain an epoxy resin with less hydrolyzable halogen, the obtained epoxy resin is again dissolved in an organic solvent such as toluene, methyl isobutyl ketone, methyl ethyl ketone, and alkali metal hydroxide such as sodium hydroxide or potassium hydroxide. Further reaction can be carried out by adding an aqueous solution of the product. At this time, a phase transfer catalyst such as a quaternary ammonium salt or crown ether may be present for the purpose of improving the reaction rate. When the phase transfer catalyst is used, the amount used is preferably 0.1 to 3.0 parts by mass with respect to 100 parts by mass of the epoxy resin used. After completion of the reaction, the produced salt is removed by filtration, washing with water, etc., and further, the target epoxy resin of the present invention can be obtained by distilling off a solvent such as toluene and methyl isobutyl ketone under heating and reduced pressure.

  The curable composition of the present invention uses the trifunctional epoxy compound (A1) detailed above as an essential component of the main agent, and uses the cyanate ester compound (B) described below as a curing agent. As described above, the cured product obtained using the cyanate ester compound (B) is inferior in anti-toughness with excellent heat resistance and has a chain structure such as a phenol novolac type epoxy resin that has been mainly used conventionally. When used in combination with an epoxy resin, for example, cracking and swelling are likely to occur in a moisture and solder resistance test. However, since the trifunctional epoxy compound (A1) used in the present invention has high molecular orientation and high toughness in the cured product, it can be used in combination with the cyanate ester compound (B). Further, a cured product having excellent moisture resistance and solder resistance can be obtained.

  Specific examples of the cyanate ester compound (B) used in the present invention include compounds obtained by reacting a phenolic hydroxyl group-containing compound with cyanogen halide in the presence of a basic substance. It may be quantified.

  Examples of the cyanogen halide used here include cyanogen chloride and cyanogen bromide.

  On the other hand, phenolic hydroxyl group-containing compounds to be reacted with cyanogen halide are, for example, bisphenol A, bisphenol F, fluorene bisphenol, bis (4-hydroxyphenyl) menthane, bis (4-hydroxyphenyl) dicyclopentane, 4,4 ′. -Dihydroxybenzophenone, bis (4-hydroxydiphenyl) ether, bis (4-hydroxy-3-methylphenyl) ether, bis (3,5-dimethyl-4-hydroxyphenyl) ether, bis (4-hydroxyphenyl) sulfide, Bis (4-hydroxy-3-methylphenyl) sulfide, bis (3,5-dimethyl-4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone, bis (3,5-dimethyl-4-hydroxyphenyl) Methane, 1 1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxy-3-methylphenyl) cyclohexane, 1,1-bis (3,5-dimethyl-4-hydroxyphenyl) cyclohexane, 1,1 '-Bis (3-tert-butyl-6-methyl-4-hydroxyphenyl) butane, bis (3,5-dimethyl-4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) ethane, 4,4'- Bisphenols such as hexafluoroisopropylidenediphenol; biphenol derivatives, biphenols such as 1,1′-binaphthalene-2,2′-diol, 1,1′-bis (2-hydroxy-1-naphthyl) methane (b ), 1,1′-bis (2-hydroxy-1-naphthyl-6methyl) methane, 1,1′-bis (2-hydride) Bisnaphthols such as xyl-1-naphthyl-7ethyl) butane; tris- (4-hydroxyphenyl) methane, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, phenol novolak, o-cresol novolak And the like.

  Among these, bisphenol A, bis (3,5-dimethyl-4-hydroxyphenyl) ether, and phenol novolak resin are preferable in terms of reactivity with cyanogen halide, solubility of the reaction product, and compatibility.

  That is, the cyanate ester compound (B) is obtained by reacting bisphenol A with cyanogen halide, reacting bis (3,5-dimethyl-4-hydroxyphenyl) ether with cyanogen halide. A compound obtained by reacting a compound obtained or a phenol novolak resin with cyanogen halide is preferred. Furthermore, since a cured product having more excellent heat resistance is obtained, a compound obtained by reacting bisphenol A and cyanogen halide or a compound obtained by reacting phenol novolac resin and cyanogen halide is more preferable.

  The reaction between the phenolic hydroxyl group-containing compound and the cyanogen halide is preferably carried out in the presence of a basic catalyst for the purpose of enhancing the reactivity. Examples of the basic catalyst used here are tertiary such as triethylamine and trimethylamine. Amines; basic substances such as alkali metal hydroxides such as sodium hydroxide and potassium hydroxide.

  Specifically, the reaction between the phenolic hydroxyl group-containing compound and the cyanogen halide is, for example, a ratio of 1.05 mol to 1.5 mol of cyanogen halide with respect to 1 mol of the phenolic hydroxyl group in the phenol compound. It can be obtained by reacting.

  The above reaction is preferably performed in the presence of an organic solvent. Examples of the organic solvent used in this case include aromatic solvents such as benzene, toluene and xylene, and ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone.

  After carrying out the reaction under the above conditions, an appropriate amount of water is added to the reaction solution to dissolve the produced salt. Thereafter, washing with water is repeated to remove the generated salt in the system, and further purification is performed by dehydration or filtration, and the organic solvent is removed by distillation to obtain the desired cyanate ester compound (B). .

  The blending amount of the epoxy resin component and the cyanate ester compound (B) in the curable composition of the present invention is not particularly limited, but the curable composition is obtained because the obtained cured product has good characteristics. It is preferable that the cyanate group in the cyanate ester compound (B) is 0.5 to 2.5 equivalents with respect to a total of 1 equivalent of the epoxy groups therein.

  The curable composition of the present invention includes, as an epoxy resin component, the trifunctional epoxy compound (A1), the dimer compound (A2), the tetrafunctional epoxy compound (A3), and the other polyfunctional epoxy compounds (A4). An epoxy resin (A ′) other than the above (hereinafter abbreviated as “other epoxy resin (A ′)”) may be used. In this case, the amount of the other epoxy resin (A ′) used may be in a range that does not impair the effects of the present invention. Specifically, it is 70% by mass or less, preferably, based on the total mass of the epoxy resin component. Other epoxy resins used in a range of 60% by mass or less can be used in combination.

  As the other epoxy resins used here, various epoxy resins can be used. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenyl type epoxy resin, tetramethylbiphenyl type epoxy resin, phenol novolac type Epoxy resin, cresol novolak type epoxy resin, bisphenol A novolak type epoxy resin, triphenylmethane type epoxy resin, tetraphenylethane type epoxy resin, dicyclopentadiene-phenol addition reaction type epoxy resin, phenol aralkyl type epoxy resin, naphthol novolak type Epoxy resin, naphthol aralkyl epoxy resin, naphthol-phenol co-condensed novolac epoxy resin, aromatic hydrocarbon formaldehyde resin modified pheno Resin type epoxy resin, a biphenyl novolak type epoxy resins.

  Among these, phenol aralkyl type epoxy resins, biphenyl novolac type epoxy resins, naphthol novolak type epoxy resins containing a naphthalene skeleton, naphthol aralkyl type epoxy resins, naphthol-phenol co-condensed novolak type epoxy resins, and crystalline biphenyl Type epoxy resin, tetramethylbiphenyl type epoxy resin, xanthene type epoxy resin, alkoxy group-containing aromatic ring-modified novolak type epoxy resin (compound in which glycidyl group-containing aromatic ring and alkoxy group-containing aromatic ring are linked with formaldehyde), etc. are heat resistant It is particularly preferable from the viewpoint of obtaining a cured product having excellent properties.

  In the curable resin composition of the present invention, a curing agent other than the cyanate ester compound (B) (hereinafter abbreviated as “other curing agent (B ′)”) is within a range that does not impair the effects of the present invention. It can also be added. At this time, the ratio of the cyanate ester compound (B) to the other curing agent (B ′) is 30 parts by mass or more of the cyanate ester compound (B) with respect to 100 parts by mass of the total curing agent component. A ratio is preferable, and a ratio of 40 parts by mass or more is more preferable.

  Examples of the other curing agent (B ′) include amine compounds, amide compounds, acid anhydride compounds, phenol compounds, and the like. Specifically, examples of the amine compound include diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, imidazole, BF3-amine complex, and guanidine derivatives.

  Examples of the amide compound include polyamide resins synthesized from dimer of dicyandiamide and linolenic acid and ethylenediamine.

  Examples of the acid anhydride compound include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methyl nadic anhydride, hexahydrophthalic anhydride, And methyl hexahydrophthalic anhydride.

  Examples of the phenolic compounds include phenol novolac resins, cresol novolac resins, aromatic hydrocarbon formaldehyde resin-modified phenol resins, dicyclopentadiene phenol addition type resins, phenol aralkyl resins (Zylok resins), and resorcin novolac resins. Polyhydric phenol novolak resin, naphthol aralkyl resin, trimethylol methane resin, tetraphenylol ethane resin, naphthol novolak resin, naphthol-phenol co-condensed novolak resin, naphthol-cresol co-condensed novolac resin synthesized from polyvalent hydroxy compound and formaldehyde , Biphenyl modified phenolic resin (polyhydric phenol compound with phenolic nuclei linked by bismethylene group), biphenyl modified naphthol resin ( Polyvalent naphthol compounds with phenolic nuclei linked by smethylene groups), aminotriazine-modified phenolic resins (polyhydric phenolic compounds with phenolic nuclei linked by melamine, benzoguanamine, etc.) and alkoxy group-containing aromatic ring-modified novolak resins (phenolic with formaldehyde) And a polyphenol compound such as a polyphenol compound having a nucleus and an alkoxy group-containing aromatic ring linked to each other. Among these other curing agent components, the phenolic compound is preferable because of its excellent curability.

  When the curable composition of the present invention contains other epoxy resin (A ′) and the other curing agent (B ′), the total of 1 equivalent of epoxy groups contained in the curable composition, It is preferable that the ratio of the cyanate group and active hydrogen contained in the curing agent component is in the range of 0.5 to 2.5 equivalents.

  In this invention, a hardening accelerator can also be used together suitably as needed. Various curing accelerators can be used, and examples thereof include phosphorus compounds, tertiary amines, imidazoles, organic acid metal salts, Lewis acids, and amine complex salts. In particular, when used as a semiconductor sealing material, it is excellent in curability, heat resistance, electrical characteristics, moisture resistance reliability, etc., so that 2-ethyl-4-methylimidazole is used for imidazole compounds, and triphenylphosphine is used for phosphorus compounds. For fins and tertiary amines, 1,8-diazabicyclo- [5.4.0] -undecene (DBU) is preferred.

  When adjusting the curable composition of this invention explained in full detail above to the varnish for printed wiring boards, etc., it is preferable to mix | blend an organic solvent (C) other than said each component. Examples of the organic solvent that can be used here include methyl ethyl ketone, acetone, dimethylformamide, methyl isobutyl ketone, methoxypropanol, cyclohexanone, methyl cellosolve, ethyl diglycol acetate, propylene glycol monomethyl ether acetate, etc. The amount used can be appropriately selected depending on the application. For example, in printed wiring board applications, it is preferable to use a polar solvent having a boiling point of 160 ° C. or less, such as methyl ethyl ketone, acetone, dimethylformamide, and the non-volatile content of 40 to 80% by mass. It is preferable to use in the ratio which becomes. On the other hand, in build-up adhesive film applications, as organic solvents, for example, ketone solvents such as acetone, methyl ethyl ketone, cyclohexanone, ester solvents such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, carbitol acetate, cellosolve It is preferable to use carbitol solvents such as butyl carbitol, aromatic hydrocarbon solvents such as toluene and xylene, dimethylformamide, dimethylacetamide, N-methylpyrrolidone and the like, and the non-volatile content is 30 to 60% by mass. It is preferable to use in proportions.

  In order to further improve the flame retardancy, the curable composition of the present invention may contain a non-halogen flame retardant that substantially does not contain a halogen atom, for example, in printed wiring board applications.

  Examples of the non-halogen flame retardants include phosphorus flame retardants, nitrogen flame retardants, silicone flame retardants, inorganic flame retardants, and organic metal salt flame retardants. The flame retardants may be used alone or in combination, and a plurality of flame retardants of the same system may be used, or different types of flame retardants may be used in combination.

  As the phosphorus flame retardant, either inorganic or organic can be used. Examples of the inorganic compounds include red phosphorus, monoammonium phosphate, diammonium phosphate, triammonium phosphate, ammonium phosphates such as ammonium polyphosphate, and inorganic nitrogen-containing phosphorus compounds such as phosphate amide. .

  The red phosphorus is preferably subjected to a surface treatment for the purpose of preventing hydrolysis and the like. Examples of the surface treatment method include (i) magnesium hydroxide, aluminum hydroxide, zinc hydroxide, water A method of coating with an inorganic compound such as titanium oxide, bismuth oxide, bismuth hydroxide, bismuth nitrate or a mixture thereof; (ii) an inorganic compound such as magnesium hydroxide, aluminum hydroxide, zinc hydroxide, titanium hydroxide; and A method of coating with a mixture of thermosetting resins such as phenolic resin, and (iii) thermosetting of phenolic resin on a coating of an inorganic compound such as magnesium hydroxide, aluminum hydroxide, zinc hydroxide or titanium hydroxide. For example, a method of double coating with a resin may be used.

  Examples of the organic phosphorus compound include, for example, general-purpose organic phosphorus compounds such as phosphate ester compounds, phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, phosphorane compounds, organic nitrogen-containing phosphorus compounds, and 9,10- Dihydro-9-oxa-10-phosphaphenanthrene = 10-oxide, 10- (2,5-dihydrooxyphenyl) -10H-9-oxa-10-phosphaphenanthrene = 10-oxide, 10- (2,7- Examples thereof include cyclic organophosphorus compounds such as dihydrooxynaphthyl) -10H-9-oxa-10-phosphaphenanthrene = 10-oxide, and derivatives obtained by reacting them with compounds such as epoxy resins and phenol resins.

  The blending amount thereof is appropriately selected depending on the type of phosphorus-based flame retardant, other components of the curable composition, and the desired degree of flame retardancy. For example, epoxy components, curing agents, non- and In 100 parts by mass of the curable composition in which all other fillers and additives are blended, when red phosphorus is used as a non-halogen flame retardant, it may be blended in the range of 0.1 to 2.0 parts by mass. Preferably, when an organic phosphorus compound is used, it is preferably blended in the range of 0.1 to 10.0 parts by mass, and particularly preferably in the range of 0.5 to 6.0 parts by mass.

  In addition, when using the phosphorous flame retardant, the phosphorous flame retardant may be used in combination with hydrotalcite, magnesium hydroxide, boric compound, zirconium oxide, black dye, calcium carbonate, zeolite, zinc molybdate, activated carbon, etc. Good.

  Examples of the nitrogen-based flame retardant include triazine compounds, cyanuric acid compounds, isocyanuric acid compounds, phenothiazines, and the like, and triazine compounds, cyanuric acid compounds, and isocyanuric acid compounds are preferable.

  Examples of the triazine compound include melamine, acetoguanamine, benzoguanamine, melon, melam, succinoguanamine, ethylene dimelamine, melamine polyphosphate, triguanamine, and the like, for example, (i) guanylmelamine sulfate, melem sulfate, sulfate (Iii) co-condensates of phenolic compounds such as phenol, cresol, xylenol, butylphenol, and nonylphenol with melamines such as melamine, benzoguanamine, acetoguanamine, formguanamine and formaldehyde; ) A mixture of the cocondensate of (ii) and a phenol resin such as a phenol formaldehyde condensate, (iv) Those obtained by further modifying (ii) and (iii) with paulownia oil, isomerized linseed oil, etc. It is done.

  Specific examples of the cyanuric acid compound include cyanuric acid and cyanuric acid melamine.

  The compounding amount of the nitrogen-based flame retardant is appropriately selected depending on the type of the nitrogen-based flame retardant, the other components of the curable composition, and the desired degree of flame retardancy. It is preferable to mix in the range of 0.05 to 10 parts by mass, especially in 0.1 to 10 parts by mass, in 100 parts by mass of the curable composition containing all of the agent, non-halogen flame retardant and other fillers and additives. It is preferable to mix in the range of 5 parts by mass.

  Moreover, when using the said nitrogen-type flame retardant, you may use together a metal hydroxide, a molybdenum compound, etc.

  The silicone flame retardant is not particularly limited as long as it is an organic compound containing a silicon atom, and examples thereof include silicone oil, silicone rubber, and silicone resin.

  The amount of the silicone-based flame retardant is appropriately selected depending on the type of the silicone-based flame retardant, the other components of the curable resin composition, and the desired degree of flame retardancy. For example, an epoxy component, It is preferable to mix in the range of 0.05 to 20 parts by mass in 100 parts by mass of the curable composition containing all of the curing agent, non-halogen flame retardant and other fillers and additives. Moreover, when using the said silicone type flame retardant, you may use a molybdenum compound, an alumina, etc. together.

  Examples of the inorganic flame retardant include metal hydroxide, metal oxide, metal carbonate compound, metal powder, boron compound, and low melting point glass.

  Specific examples of the metal hydroxide include aluminum hydroxide, magnesium hydroxide, dolomite, hydrotalcite, calcium hydroxide, barium hydroxide, zirconium hydroxide and the like.

  Specific examples of the metal oxide include, for example, zinc molybdate, molybdenum trioxide, zinc stannate, tin oxide, aluminum oxide, iron oxide, titanium oxide, manganese oxide, zirconium oxide, zinc oxide, molybdenum oxide, and cobalt oxide. Bismuth oxide, chromium oxide, nickel oxide, copper oxide, tungsten oxide and the like.

  Specific examples of the metal carbonate compound include zinc carbonate, magnesium carbonate, calcium carbonate, barium carbonate, basic magnesium carbonate, aluminum carbonate, iron carbonate, cobalt carbonate, and titanium carbonate.

  Specific examples of the metal powder include aluminum, iron, titanium, manganese, zinc, molybdenum, cobalt, bismuth, chromium, nickel, copper, tungsten, and tin.

  Specific examples of the boron compound include zinc borate, zinc metaborate, barium metaborate, boric acid, and borax.

  Specific examples of the low-melting-point glass include, for example, Shipley (Bokusui Brown), hydrated glass SiO2-MgO-H2O, PbO-B2O3-based, ZnO-P2O5-MgO-based, P2O5-B2O3-PbO-MgO-based, Examples thereof include glassy compounds such as P—Sn—O—F, PbO—V 2 O 5 —TeO 2, Al 2 O 3 —H 2 O, and lead borosilicate.

  The blending amount of the inorganic flame retardant is appropriately selected according to the type of the inorganic flame retardant, the other components of the curable composition, and the desired degree of flame retardancy. It is preferable to mix in the range of 0.5 to 50 parts by mass, particularly 5 to 30 parts by mass, in 100 parts by mass of the curable composition containing all of the agent, non-halogen flame retardant and other fillers and additives. It is preferable to blend in the range of parts.

  Examples of the organic metal salt flame retardant include ferrocene, acetylacetonate metal complex, organic metal carbonyl compound, organic cobalt salt compound, organic sulfonic acid metal salt, metal atom and aromatic compound or heterocyclic compound or an ionic bond or Examples thereof include a coordinated compound.

  The amount of the organic metal salt-based flame retardant is appropriately selected depending on the type of the organic metal salt-based flame retardant, the other components of the curable composition, and the desired degree of flame retardancy. It is preferable to mix in the range of 0.005 to 10 parts by mass in 100 parts by mass of the curable composition containing all of the epoxy component, curing agent, non-halogen flame retardant and other fillers and additives.

  An inorganic filler can be mix | blended with the curable composition of this invention as needed. Examples of the inorganic filler include fused silica, crystalline silica, alumina, silicon nitride, and aluminum hydroxide. When particularly increasing the blending amount of the inorganic filler, it is preferable to use fused silica. The fused silica can be used in either a crushed shape or a spherical shape. However, in order to increase the blending amount of the fused silica and suppress an increase in the melt viscosity of the molding material, it is preferable to mainly use a spherical shape. In order to further increase the blending amount of the spherical silica, it is preferable to appropriately adjust the particle size distribution of the spherical silica. The filling rate is preferably in the range of 0.5 to 100 parts by mass in 100 parts by mass of the curable composition. Moreover, when using for uses, such as an electrically conductive paste, electroconductive fillers, such as silver powder and copper powder, can be used.

  Various compounding agents, such as a silane coupling agent, a mold release agent, a pigment, an emulsifier, can be added to the curable composition of this invention as needed.

  The curable composition of this invention is obtained by mixing each above-mentioned component uniformly. The curable composition of the present invention in which an epoxy component, a curing agent and, if necessary, a curing accelerator are blended can be easily made into a cured product by a method similar to a conventionally known method. Examples of the cured product include molded cured products such as laminates, cast products, adhesive layers, coating films, and films.

  Applications for which the curable composition of the present invention is used include printed wiring board materials, resin casting materials, adhesives, interlayer insulation materials for build-up substrates, and adhesive films for build-up. Among these various applications, in printed circuit boards, insulating materials for electronic circuit boards, and adhesive films for build-up, passive parts such as capacitors and active parts such as IC chips are embedded in so-called electronic parts. It can be used as an insulating material for a substrate. Among these, it is preferable to use for the printed wiring board material and the adhesive film for buildup from the characteristics, such as high heat resistance and a flame retardance.

  Here, in order to produce a printed circuit board from the curable composition of the present invention, a resin composition blended with the organic solvent (C) and varnished is impregnated into a reinforcing base material, and a copper foil is overlaid and heated. The method of making it crimp is mentioned. Examples of the reinforcing substrate that can be used here include paper, glass cloth, glass nonwoven fabric, aramid paper, aramid cloth, glass mat, and glass roving cloth. More specifically, the varnish-like curable composition described above is first heated at a heating temperature corresponding to the solvent type used, preferably 50 to 170 ° C., so that a prepreg as a cured product is obtained. obtain. Although it does not specifically limit as a mass ratio of the curable composition used at this time and a reinforcement base material, Usually, it is preferable to prepare so that the resin part in a prepreg may be 20-60 mass%. Next, the prepreg obtained as described above is laminated by a conventional method, and a copper foil is appropriately stacked, and then subjected to thermocompression bonding at a pressure of 1 to 10 MPa at 170 to 250 ° C. for 10 minutes to 3 hours, A desired printed circuit board can be obtained.

  When the curable composition of the present invention is used as a resist ink, for example, a cationic polymerization catalyst is used as a catalyst for the curable composition, and a pigment, talc, and filler are further added to form a resist ink composition. Then, after apply | coating on a printed circuit board by a screen printing system, the method of setting it as a resist ink hardened | cured material is mentioned.

  When the curable composition of the present invention is used as a conductive paste, for example, a method of dispersing fine conductive particles in the curable composition to obtain a composition for an anisotropic conductive film, which is liquid at room temperature Examples of the method include a paste resin composition for circuit connection and an anisotropic conductive adhesive.

  As a method for obtaining an interlayer insulating material for a build-up substrate from the curable composition of the present invention, for example, the curable composition appropriately blended with rubber, filler, etc. After applying using a coating method or the like, it is cured. Then, after drilling a predetermined through-hole part etc. as needed, it treats with a roughening agent, forms the unevenness | corrugation by washing the surface with hot water, and metal-treats, such as copper. As the plating method, electroless plating or electrolytic plating treatment is preferable, and examples of the roughening agent include an oxidizing agent, an alkali, and an organic solvent. Such operations are sequentially repeated as desired, and a build-up base can be obtained by alternately building up and forming the resin insulating layer and the conductor layer having a predetermined circuit pattern. However, the through-hole portion is formed after the outermost resin insulating layer is formed. Moreover, a roughened surface is formed by heat-pressing a copper foil with resin obtained by semi-curing the curable composition on a copper foil onto a wiring board on which a circuit is formed at 170 to 250 ° C. It is also possible to produce a build-up substrate by omitting this process.

  The method for producing an adhesive film for buildup from the curable composition of the present invention is, for example, applied for a multilayer printed wiring board by applying the curable composition of the present invention on a support film to form a resin composition layer. The method of setting it as an adhesive film is mentioned.

  When the curable composition of the present invention is used for an adhesive film for build-up, the adhesive film is softened under a lamination temperature condition (usually 70 ° C. to 140 ° C.) in a vacuum laminating method. It is important to show fluidity (resin flow) capable of filling the via hole or through hole in the substrate, and it is preferable to blend the above-described components so as to exhibit such characteristics.

  Here, the diameter of the through hole of the multilayer printed wiring board is usually 0.1 to 0.5 mm, and the depth is usually 0.1 to 1.2 mm. It is usually preferable to allow resin filling in this range. When laminating both surfaces of the circuit board, it is desirable to fill about 1/2 of the through hole.

  Specifically, the method for producing the above-mentioned adhesive film is prepared by preparing the varnish-like curable composition of the present invention, and then applying the varnish-like composition to the surface of the support film (y). It can be produced by drying the organic solvent by heating or blowing hot air to form the layer (x) of the curable resin composition.

  The thickness of the formed layer (x) is usually not less than the thickness of the conductor layer. Since the thickness of the conductor layer of the circuit board is usually in the range of 5 to 70 μm, the thickness of the resin composition layer is preferably 10 to 100 μm.

  In addition, the layer (x) in this invention may be protected with the protective film mentioned later. By protecting with a protective film, it is possible to prevent dust and the like from being attached to the surface of the curable composition layer and scratches.

  The above-mentioned support film and protective film are made of polyolefin such as polyethylene, polypropylene and polyvinyl chloride, polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”), polyester such as polyethylene naphthalate, polycarbonate, polyimide, and further. Examples thereof include metal foil such as pattern paper, copper foil, and aluminum foil. In addition, the support film and the protective film may be subjected to a release treatment in addition to the mud treatment and the corona treatment.

  Although the thickness of a support film is not specifically limited, Usually, it is 10-150 micrometers, Preferably it is used in 25-50 micrometers. Moreover, it is preferable that the thickness of a protective film shall be 1-40 micrometers.

  The support film (y) described above is peeled off after being laminated on a circuit board or after forming an insulating layer by heat curing. If the support film (y) is peeled after the adhesive film is heat-cured, adhesion of dust and the like in the curing process can be prevented. In the case of peeling after curing, the support film is usually subjected to a release treatment in advance.

  Next, a method for producing a multilayer printed wiring board using the adhesive film obtained as described above is, for example, when the layer (x) is protected with a protective film, after peeling these layers ( x) is laminated on one side or both sides of the circuit board so as to be in direct contact with the circuit board, for example, by a vacuum laminating method. The laminating method may be a batch method or a continuous method using a roll. Further, the adhesive film and the circuit board may be heated (preheated) as necessary before lamination.

  The lamination conditions are such that the pressure bonding temperature (laminating temperature) is preferably 70 to 140 ° C., the pressure bonding pressure is preferably 1 to 11 kgf / cm 2 (9.8 × 10 4 to 107.9 × 104 N / m 2), and the air pressure is 20 mmHg (26 It is preferable to laminate under a reduced pressure of 0.7 hPa or less.

  What is necessary is just to heat the composition obtained by the said method in the temperature range about 20-250 degreeC as a method of obtaining the hardened | cured material of this invention.

Next, the present invention will be described in more detail with reference to examples and comparative examples.
"" Is based on mass unless otherwise specified. The softening point, ¹³ C-NMR, GPC and MS were measured under the following conditions.

1) Softening point measurement method: JIS K7234

2) ¹³ C-NMR: Measurement conditions are as follows.
Device: AL-400 manufactured by JEOL Ltd.
Measurement mode: SGNNE (1H complete decoupling method of NOE elimination)
Solvent: Dimethyl sulfoxide pulse angle: 45 ° C pulse Sample concentration: 30 wt%
Integration count: 10,000 times

3) GPC: The measurement conditions are as follows.
Measuring device: “HLC-8220 GPC” manufactured by Tosoh Corporation
Column: Guard column “HXL-L” manufactured by Tosoh Corporation
+ "TSK-GEL G2000HXL" manufactured by Tosoh Corporation
+ "TSK-GEL G2000HXL" manufactured by Tosoh Corporation
+ Tosoh Corporation “TSK-GEL G3000HXL”
+ Tosoh Corporation “TSK-GEL G4000HXL”
Detector: RI (differential refractometer)
Data processing: “GPC-8020 Model II version 4.10” manufactured by Tosoh Corporation
Measurement conditions: Column temperature 40 ° C
Developing solvent Tetrahydrofuran
Flow rate: 1.0 ml / min Standard: The following monodisperse polystyrene having a known molecular weight was used in accordance with the measurement manual of “GPC-8020 Model II version 4.10”.

(Polystyrene used)
“A-500” manufactured by Tosoh Corporation
"A-1000" manufactured by Tosoh Corporation
"A-2500" manufactured by Tosoh Corporation
"A-5000" manufactured by Tosoh Corporation
“F-1” manufactured by Tosoh Corporation
"F-2" manufactured by Tosoh Corporation
“F-4” manufactured by Tosoh Corporation
“F-10” manufactured by Tosoh Corporation
“F-20” manufactured by Tosoh Corporation
“F-40” manufactured by Tosoh Corporation
“F-80” manufactured by Tosoh Corporation
“F-128” manufactured by Tosoh Corporation
Sample: A 1.0 mass% tetrahydrofuran solution filtered in terms of resin solids and filtered through a microfilter (50 μl).

4) MS: Double Density Mass Spectrometer AX505H (FD505 manufactured by JEOL Ltd.)
H)

Production Example 1 Production of Epoxy Resin (A-1) In a flask equipped with a thermometer, a dropping funnel, a condenser tube, a fractionating tube, and a stirrer, 216 parts by mass (1.5 mol) of β-naphthol, 250 masses of isopropyl alcohol Part, 37% 37% formalin aqueous solution 122 parts by mass (1.50 mol), 49% sodium hydroxide 31 parts by mass (0.38 mol) was charged from room temperature to 75 ° C. with stirring, and 75 ° C. for 1 hour. Stir. Subsequently, 81 parts by mass (0.75 mol) of paracresol was charged, and further stirred at 75 ° C. for 8 hours. After completion of the reaction, the reaction mixture was neutralized by adding 45 parts by mass of primary sodium phosphate, added with 630 parts by mass of methyl isobutyl ketone, washed with 158 parts by weight of water three times, dried under heating under reduced pressure, and cresol- As a result, 290 parts by mass of naphthol resin (a-1) was obtained. A GPC chart of the obtained cresol-naphthol resin (a-1) is shown in FIG. The hydroxyl equivalent of the cresol-naphthol resin (a-1) was 140 g / equivalent, and the content of the trifunctional compound represented by the following structural formula (a) calculated from the GPC chart was 83.5%. .

Next, 140 parts by mass of the cresol-naphthol resin (a-1) obtained by the above reaction while performing a nitrogen gas purge on a flask equipped with a thermometer, a condenser tube, and a stirrer, and 463 parts by mass of epichlorohydrin (5.0 mol) and 53 parts by mass of n-butanol were charged and dissolved while stirring. After the temperature was raised to 50 ° C., 220 parts by mass of a 20% aqueous sodium hydroxide solution (1.10 mol) was added over 3 hours, and the reaction was further continued at 50 ° C. for 1 hour. After completion of the reaction, stirring was stopped, the aqueous layer accumulated in the lower layer was removed, stirring was resumed, and unreacted epichlorohydrin was distilled off under reduced pressure at 150 ° C. Then, 300 parts by mass of methyl isobutyl ketone and 50 parts by mass of n-butanol were added to the resulting crude epoxy resin and dissolved. Further, 15 parts by mass of a 10% by mass sodium hydroxide aqueous solution was added to this solution and reacted at 80 ° C. for 2 hours, and then washing with 100 parts by mass of water was repeated three times until the pH of the cleaning solution became neutral. Next, the system was dehydrated by azeotropic distillation, and after microfiltration, the solvent was distilled off under reduced pressure to obtain 190 parts by mass of the desired epoxy resin (A-1). The GPC chart of the obtained epoxy resin (A-1) is shown in FIG. 2, the ¹³ C-NMR chart is shown in FIG. 3, and the MS spectrum is shown in FIG. Epoxy resin (A-1) had an epoxy equivalent of 240 g / equivalent, a softening point of 97 ° C., and a molecular weight distribution (Mw / Mn) of 1.17. Further, 588 peaks representing a trifunctional epoxy compound (A1) represented by the following structural formula (b) were detected from the MS spectrum. The content of the trifunctional epoxy compound (A1) represented by the following structural formula (b) calculated from the GPC chart is 63.3%, and the dimer compound (A2 represented by the structural formula (2) ) Content was 4.8%.

Production Example 2 Production of Epoxy Resin (A-2) A flask equipped with a thermometer, a dropping funnel, a condenser tube, a fractionating tube, and a stirrer, 216 parts by mass of β-naphthol (1.5 mol), 250 parts by mass of isopropyl alcohol Part, 37% 37% formalin aqueous solution 122 parts by mass (1.50 mol), 49% sodium hydroxide 31 parts by mass (0.38 mol) was charged from room temperature to 75 ° C. with stirring, and 75 ° C. for 1 hour. Stir. Subsequently, 81 parts by mass (0.75 mol) of ortho-cresol was charged and further stirred at 75 ° C. for 8 hours. After completion of the reaction, the reaction mixture was neutralized by adding 45 parts by mass of primary sodium phosphate, added with 630 parts by mass of methyl isobutyl ketone, repeatedly washed three times with 158 parts by mass of water, dried under heating under reduced pressure, and cresol- As a result, 290 parts by mass of naphthol resin (a-2) was obtained. A GPC chart of the obtained cresol-naphthol resin (a-2) is shown in FIG. The hydroxyl equivalent of the cresol-naphthol resin (a-2) was 140 g / equivalent, and the content of the trifunctional compound represented by the following structural formula (a) calculated from the GPC chart was 51.5%. .

Next, 140 parts by mass of cresol-naphthol resin (a-2) (hydroxyl group 1.0 equivalent) obtained by the above reaction while performing a nitrogen gas purge on a flask equipped with a thermometer, a condenser, and a stirrer, 463 parts by mass of epichlorohydrin (5.0 mol) and 53 parts by mass of n-butanol were charged and dissolved while stirring. After the temperature was raised to 50 ° C., 220 parts by mass of a 20% aqueous sodium hydroxide solution (1.10 mol) was added over 3 hours, and the reaction was further continued at 50 ° C. for 1 hour. After completion of the reaction, stirring was stopped, the aqueous layer accumulated in the lower layer was removed, stirring was resumed, and unreacted epichlorohydrin was distilled off under reduced pressure at 150 ° C. Then, 300 parts by mass of methyl isobutyl ketone and 50 parts by mass of n-butanol were added to the resulting crude epoxy resin and dissolved. Further, 15 parts by mass of a 10% by mass sodium hydroxide aqueous solution was added to this solution and reacted at 80 ° C. for 2 hours, and then washing with 100 parts by mass of water was repeated three times until the pH of the cleaning solution became neutral. Next, the system was dehydrated by azeotropic distillation, and after microfiltration, the solvent was distilled off under reduced pressure to obtain 192 parts by mass of the desired epoxy resin (A-2). The GPC chart of the resulting epoxy resin (A-2) is shown in FIG. 6, the ¹³ C-NMR chart is shown in FIG. 7, and the MS spectrum is shown in FIG. The epoxy equivalent of the epoxy resin (A-2) was 227 g / equivalent, the softening point was 78 ° C., and the molecular weight distribution (Mw / Mn) was 1.25. Further, 588 peaks representing a trifunctional epoxy compound (A1) represented by the following structural formula (b) were detected from the MS spectrum. The content of the component corresponding to the dimer compound (A2) calculated from the GPC chart is 16.1%, and the component corresponding to the trifunctional epoxy compound (A1) represented by the following structural formula (b) Was 42.0%, and the content of the component corresponding to the tetrafunctional epoxy compound (A3) was 19.7%.

Comparative Production Example 1 Production of Epoxy Resin (A′-1) To a flask equipped with a thermometer, dropping funnel, condenser, fractionator, and stirrer, 505 parts by mass of α-naphthol (3.50 mol), water 158 Then, 5 parts by mass of oxalic acid and 5 parts by mass of oxalic acid were charged and stirred while raising the temperature from room temperature to 100 ° C. in 45 minutes. Subsequently, 177 parts by mass (2.45 mol) of a 42 mass% formalin aqueous solution was added dropwise over 1 hour. After completion of dropping, the mixture was further stirred at 100 ° C. for 1 hour, and then heated to 180 ° C. in 3 hours. After completion of the reaction, water remaining in the reaction system was removed under reduced pressure by heating to obtain 498 parts by mass of naphthol resin (a′-1). The hydroxyl group equivalent of the obtained naphthol resin (a′-1) was 154 g / equivalent.

  Next, 154 parts by mass of the naphthol resin (a′-1) obtained by the above reaction (hydroxyl group 1.0 equivalent) while performing nitrogen gas purging on a flask equipped with a thermometer, a condenser, and a stirrer was the same as in Example 1. Thus, 202 parts by mass of an epoxy resin (A′-1) was obtained. The epoxy equivalent of the epoxy resin (A′-1) was 237 grams / equivalent.

Examples 1 to 4 and Comparative Example 1
The curable composition was adjusted in the following manner and evaluated for moisture resistance and solder resistance. The results are shown in Table 1.

<Adjustment of curable composition>
As the epoxy component that is the main agent, (A-1), (A-2), or (A′-1) is used, and the cyanate ester compound (B-1) [Lonza's “BA-” is used as the curing agent. 200 "2,2-bis (4-cyanatephenyl) propane prepolymer] or cyanate ester compound (B-2) (" PT-30 "phenol novolac cyanate manufactured by Lonza) as octylic acid as a curing accelerator It mix | blended with the composition shown in Table 1 using zinc, and also added methyl ethyl ketone, and it adjusted so that a non volatile matter might be 58 mass%, and obtained the curable composition.

<Production of laminated plate>
A laminate was prepared under the following conditions.
Base material: Glass cloth “# 2116” (210 × 280 mm) manufactured by Nitto Boseki Co., Ltd.
Number of plies: 6 Condition of prepreg: 160 ° C
Curing conditions: 200 ° C., 40 kg / cm 2 for 1.5 hours, thickness after molding: 0.8 mm

<Evaluation of moisture and solder resistance>
The laminated plate obtained above was cut into a size of 25 mm × 50 mm, and this was used as a test piece in a pressure cooker tester at 121 ° C., 2.1 atm, 100% RH for 2 hours, and further 260 ° C. It was immersed in a solder bath for 30 seconds, and the appearance abnormality was visually confirmed.
○: No change ×: Dandruff occurred

Claims (8)

It is a polyglycidyl ether of a reaction product of paracresol, a β-naphthol compound, and formaldehyde. The following structural formula ( 1-1 )

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and G represents a glycidyl group.)
A trifunctional epoxy compound (A1-1 ) having a molecular structure represented by the following structural formula (2)

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and G represents a glycidyl group.)
The dimer epoxy compound (A2) represented by the above formula is such that the content of the trifunctional epoxy compound (A1-1) is in the range of 55 to 98% in terms of area ratio in GPC, and the dimer epoxy An epoxy resin containing the compound (A2) in an amount of 2 to 25% in terms of an area ratio in GPC ;
A curable composition comprising a cyanate ester compound (B).   The curable composition according to claim 1, wherein the total content of the trifunctional epoxy compound (A1-1) and the dimer compound (A2) in the epoxy resin is 65% or more in terms of an area ratio in GPC measurement. object. Polyglycidyl ether of the reaction product of orthocresol, β-naphthol compound, and formaldehyde
The following structural formula (1-2)

(Wherein R ¹ And R ² Each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and G represents a glycidyl group. )
A trifunctional epoxy compound (A1-2) represented by the following structural formula (2)

(Wherein R ¹ And R ² Each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and G represents a glycidyl group. )
A dimer epoxy compound (A2) represented by:
The following structural formula (3-2)

(Wherein R ¹ And R ² Each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and G represents a glycidyl group. )
A tetrafunctional epoxy compound (A3-2) represented by
The content ratio of the trifunctional epoxy compound (A1-2) is in the range of 25 to 70% in terms of area ratio in GPC measurement, and the content ratio of the dimer compound (A2) is in the range of 2 to 25 in area ratio in GPC measurement. Epoxy resin contained in a range of 10% to 40% in terms of area ratio in GPC measurement, and a content ratio of a tetrafunctional epoxy compound (A3-2),
A curable composition comprising a cyanate ester compound (B). The total content of the trifunctional epoxy compound (A1-2), the dimer compound (A2), and the tetrafunctional epoxy compound (A3-2) in the epoxy resin is 70 in terms of area ratio in GPC measurement. It is% or more, The curable composition of Claim 3. The epoxy resin further has the following structural formula (4-2)

(Wherein R ¹ And R ² Each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, G represents a glycidyl group, and n is an integer of 3 or more representing a repeating unit. )
Containing other polyfunctional epoxy compound (A4-2) represented by
The total content of the trifunctional epoxy compound (A1-2), the dimer compound (A2), and the tetrafunctional compound (A3-2) in the epoxy resin is 65% or more by area ratio in GPC measurement. And in the trifunctional epoxy compound (A1-2), the dimer compound (A2), the tetrafunctional compound (A3-2), and the polyfunctional compound (A4-2), n is 3 to 5 The curable composition according to claim 3, wherein the total content of any of the compounds is 85% or more in terms of an area ratio in GPC measurement. The cyanate ester compound (B), the compound obtained by reacting bisphenol A and a cyanogen halide, or of claims 1 to 5 which is a compound obtained by reacting a phenolic novolak resin and a cyanogen halide The curable composition of any one of Claims . Hardened | cured material formed by hardening | curing the curable composition as described in any one of Claims 1-6 . The printed wiring board which consists of a hardened | cured material of any one of Claims 1-6, a reinforcement base material, and copper foil.

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