JP2009096915A - Thermosetting resin composition, flexible substrate using the same, and electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermosetting resin composition having excellent reliability under a moisture absorption treatment condition on the assumption of a moisture condensation environment, to provide a flexible substrate using the thermosetting resin composition and to provide an electronic device. <P>SOLUTION: In the thermosetting resin composition containing (A) a resin having an acid anhydride group and/or a carboxyl group, (B) an epoxy resin and (C) an inorganic filler, (C1) aluminum hydroxide having 1.5 to 10 μm average particle diameter is included as (C) the inorganic filler. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a thermosetting resin composition, a flexible substrate using the same, and an electronic component.

  In recent years, in the field of so-called digital home appliances such as plasma and liquid crystal flat-screen TVs, digital video cameras, DVD recorders, portable audio players, etc., which have been rapidly spreading in the market, it has been responding to downsizing, thinning, and high functionality. Due to the necessity, the application and examination of new technology for mounting electronic parts in a narrow space with high density has been actively conducted. As a result of intensive studies, a mounting method called COF (ChIp On FIlm), in which a driver IC for driving a liquid crystal is directly mounted on a flexible wiring board and connected to the liquid crystal panel via an anisotropic conductive film, is high. It has been found that it is extremely advantageous for density packaging, and since 2000, it has been increasingly adopted in digital home appliances.

  A flexible wiring board (COF base material) used for COF mounting is a wiring pattern portion connected to a rigid wiring board, a driver IC, an electronic component or a liquid crystal panel as a motherboard on a polyimide film on which a conductor circuit pattern is formed. It is manufactured by forming a thermosetting resin composition layer (solder resist layer) at a location excluding, and performing a predetermined thermosetting treatment.

  As a method of forming a thermosetting resin layer (solder resist layer) on a polyimide film on which a conductor circuit pattern is formed, a liquid resin composition is screen-printed, roll-coated, curtain-coated, or the resin composition in advance. There is a method in which an object is applied onto a heat-resistant resin film to form a film and bonded by lamination. In terms of wiring board productivity, the film laminating method can form both sides of the thermosetting resin layer at the same time than the method of directly applying the liquid material to the substrate. This is advantageous in that there is no contamination and there is no contamination of the workplace with organic solvents. However, in the COF base material, a liquid material (liquid solder resist) is often used in consideration of a large number of single-sided plates, material cost, and compatibility between characteristics of heat resistance and flexibility.

  As a resin composition for a solder resist used for a COF substrate, a composition mainly composed of a polyamideimide resin represented by Patent Document 1, and a carboxyl group-containing polyurethane resin represented by Patent Document 2 as a main component. Several types of compositions have been proposed. However, it is known that the composition of Patent Document 2 has a problem in adhesion to the anisotropic conductive film, and the heat resistance and flexibility of the resist coating film and the adhesive properties to the anisotropic conductive film are known. The composition of patent document 1 which is excellent in balance is the current mainstream.

JP 2001-302895 A JP 2006-274258 A

  The composition mainly composed of the polyamideimide resin represented by Patent Document 1 described above is excellent in the heat resistance, flexibility, and adhesive property balance with the anisotropic conductive film of the resist coating film. With the rapid spread of digital home appliances, new issues have been pointed out.

  One of them is the adhesion between solder resist and anisotropic conductive film when digital home appliances are used for a long time in polar or cold regions, that is, when long-term use is assumed in a dew condensation environment. Therefore, it has been demanded that the adhesiveness between the solder resist and the anisotropic conductive film does not decrease even under the condition of moisture absorption treatment assuming that the adhesive strength is small. As a result of the investigation, the polyamide-imide resin composition represented by Patent Document 1 has high adhesion between the solder resist and the anisotropic conductive film in a room temperature environment, but the decrease in the adhesion under moisture absorption conditions. There was a problem that the rate was large and further improvement was necessary.

  The present invention has been made in order to solve the conventional problems as described above, and is not only in a room temperature environment but also in a solder resist and anisotropic conductivity even under moisture absorption treatment conditions assuming a condensation environment. It aims at providing the thermosetting resin composition with favorable adhesive force with an adhesive film, a flexible substrate using the same, and an electronic component.

  The thermosetting resin composition according to the present invention comprises (A) a resin having an acid anhydride group and / or a carboxyl group, (B) an epoxy resin, and (C) an inorganic filler. It is a composition, Comprising: (C1) Aluminum hydroxide with an average particle diameter of 1.5-10 micrometers is contained as said (C) inorganic filler, It is characterized by the above-mentioned.

  In the thermosetting resin composition according to the present invention, the (A) resin having an acid anhydride group and / or a carboxyl group is a resin having a urethane bond.

  In the thermosetting resin composition according to the present invention, the resin (A) having an acid anhydride group and / or a carboxyl group has a polycarbonate skeleton.

  Further, in the thermosetting resin composition according to the present invention, the content of the (B) epoxy resin is based on 100 parts by weight of the resin having the (A) acid anhydride group and / or carboxyl group. 15 to 50 parts by weight.

  Moreover, in the thermosetting resin composition according to the present invention, the (C1) aluminum hydroxide content is based on 100 parts by weight of the resin having the (A) acid anhydride group and / or carboxyl group. It is characterized by being 10 to 40 parts by weight.

  In the thermosetting resin composition according to the present invention, the thermosetting resin composition further includes (D) a crosslinking agent.

Moreover, in the thermosetting resin composition by this invention, the said thermosetting resin composition is used as a protective film of the flexible printed circuit board which laminated | stacked copper foil on the polyimide base material.

  In the flexible substrate according to the present invention, the thermosetting resin composition is used.

  The electronic component according to the present invention is characterized by using the flexible substrate.

  According to the present invention, there are provided a thermosetting resin composition having an excellent adhesive force with an anisotropic conductive adhesive film even under moisture absorption treatment conditions assuming a condensation environment, a flexible substrate and an electronic component using the same. There is an effect that can be.

  Hereinafter, a thermosetting resin composition according to the present invention, a flexible substrate using the same, and an electronic component will be described in detail by embodiments. In addition, this invention is not limited by this embodiment.

[Thermosetting resin composition]
The thermosetting resin composition according to the present invention comprises (A) a resin having an acid anhydride group and / or a carboxyl group, (B) an epoxy resin, and (C) an inorganic filler. It is a composition, Comprising: (C1) Aluminum hydroxide with an average particle diameter of 1.5-10 micrometers is included as said (C) inorganic filler. Hereinafter, each component will be described.

[(A) component: resin having acid anhydride group and / or carboxyl group]
Among resins having an acid anhydride group and / or carboxyl group (hereinafter referred to as component (A)), as the resin having at least one acid anhydride group, epoxy resins having a butadiene structure or silicone structure, phenol resins , Acrylic resin, polyurethane, polybutadiene, water-added polybutadiene, polyester, polycarbonate, polyether, polysulfone, polytetrafluororesin, polysilicone, melamine resin, polyamide, polyamideimide, polyimide, etc. on the main chain and / or side chain Those having an acid anhydride group introduced therein may be mentioned. These can be used alone or in combination of two or more.

  Further, a resin having an acid anhydride group and / or a carboxyl group and a resin having no acid anhydride can be used in combination.

  As a method for introducing an acid anhydride group and / or carboxyl group, epoxy resin having a butadiene structure or silicone structure, phenol resin, acrylic resin, polyurethane, polybutadiene, water-added polybutadiene, polyester, polycarbonate, polyether, polysulfone, poly Tetrafluoro resin, polysilicone, melamine resin, polyamide, polyamideimide, epoxy resin-derived epoxy residue, isocyanate residue, hydroxyl group, carboxyl group and the following general formula (I) and / or general formula (II) It can be obtained by reaction.

（式中、Ｚ^１は三価の有機基を表し、Ｗは、水酸基、イソシネート基、カルボキシル基、エポキシ基、又はグリシジル基を表す。）

(In the formula, Z ¹ represents a trivalent organic group, and W represents a hydroxyl group, an isocyanate group, a carboxyl group, an epoxy group, or a glycidyl group.)

（式中、Ｚ^２は四価の有機基を表す。Ｗは、水酸基、イソシネート基、カルボキシル基、エポキシ基、又はグリシジル基を表す。）

(In the formula, Z ² represents a tetravalent organic group. W represents a hydroxyl group, an isocyanate group, a carboxyl group, an epoxy group, or a glycidyl group.)

  By introducing an acid anhydride group and / or carboxyl group at the terminal and / or side chain of the resin, the reactivity with the epoxy resin as the component (B) described later becomes high, so anisotropic conductivity under moisture absorption conditions The reduction rate of the adhesive force between the adhesive film and the flexible substrate is lowered.

  Further, the component (A) of the present invention is preferably flexible and has a low elastic modulus so as to mainly correspond to a flexible substrate or a flexible wiring board. In order to make the component (A) flexible and low elastic modulus, it is possible to introduce a component capable of improving flexibility into the main chain of the resin, such as a polybutadiene skeleton, a silicone resin skeleton, a polycarbonate skeleton, and the like. A resin having a urethane bond is preferred.

  In order to improve heat resistance, electrical properties, moisture resistance, solvent resistance and chemical resistance, it is possible to introduce a component capable of improving heat resistance into the main chain of the resin. For example, polyimide, polyamide Preference is given to imides or polyamides or resins having these skeletons. Among them, a resin having a polycarbonate skeleton and an imide skeleton is preferable from the viewpoint of flexibility, low elastic modulus, and high heat resistance.

  In the present invention, the resin containing a polycarbonate skeleton that can be used as the component (A) is usually a 1,6-hexanediol-based polycarbonate diol, a compound having a carboxyl group at the terminal, a compound having an acid anhydride, and It can be obtained by reacting with a compound having an isocyanate group at the terminal.

  In the present invention, for example, the resin that can be used as the component (A) is usually (a) a trivalent polycarboxylic acid having an acid anhydride group and a derivative thereof, and a tetravalent having an acid anhydride group. It is obtained by reacting at least one compound selected from the polycarboxylic acids (hereinafter referred to as component (a)) with (b) an isocyanate compound or an amine compound (hereinafter referred to as component (b)).

  The trivalent polycarboxylic acid having an acid anhydride group as the component (a) and its derivative are not particularly limited. For example, the following formulas (III) and (IV):

（式（ＩＩＩ）及び（ＩＶ）中、Ｒ′は、水素、炭素数１〜１０のアルキル基又はフェニル基を示し、Ｙ^１は、−ＣＨ_２−、−ＣＯ−、−ＳＯ_２−、又は−Ｏ−である。）で示される化合物を使用することができる。

(In the formulas (III) and (IV), R ′ represents hydrogen, an alkyl group having 1 to 10 carbon atoms or a phenyl group, and Y ¹ represents —CH ₂ —, —CO—, —SO ₂ —, or -O-)) can be used.

  Trimellitic anhydride is particularly preferable from the viewpoint of heat resistance and cost. Although the tetravalent polycarboxylic acid having an acid anhydride group is not particularly limited, for example, the formula (V):

（式中、Ｙ^２は、次の式（ＶＩ）で示される基：

Wherein Y ² is a group represented by the following formula (VI):

である）で示されるテトラカルボン酸二無水物を使用することができる。これらは、単独で又は２種類以上を組み合わせて使用することができる。

Can be used. These can be used alone or in combination of two or more.

  In addition to these, as necessary, an aliphatic dicarboxylic acid (succinic acid, glutaric acid, adipic acid, azelaic acid, suberic acid, sebacic acid, decanedioic acid, dodecanedioic acid, dimer acid, etc.) Aromatic dicarboxylic acids (isophthalic acid, terephthalic acid, phthalic acid, naphthalenedicarboxylic acid, oxydibenzoic acid, etc.) can be used in combination. In this case, an amide bond is also formed in the molecular chain.

  The isocyanate compound as the component (b) is, for example, the formula (VII):

（式中、複数個のＲは、それぞれ独立に炭素数１〜１８のアルキレン基であり、Ｘは二価の有機基であり、ｍ及びｎは、それぞれ独立に１〜２０の整数である。）で示されるジイソシアネート類を用いることができる（以下、（ｂ−１）化合物とする）。

(In the formula, plural Rs are each independently an alkylene group having 1 to 18 carbon atoms, X is a divalent organic group, and m and n are each independently an integer of 1 to 20.) ) Can be used (hereinafter referred to as (b-1) compound).

  The compound represented by the above formula (VII) is represented by the following formula (VIII):

（式中、Ｒは炭素数１〜１８のアルキレン基であり、ｍは１〜２０の整数である。）で示されるカーボネートジオール類と、式（ＩＸ）：
ＯＣＮ−Ｘ−ＮＣＯ （ＩＸ）
（式中、Ｘは、二価の有機基である。）で示されるジイソシアネート類を反応させることにより得られる。

(Wherein, R is an alkylene group having 1 to 18 carbon atoms, and m is an integer of 1 to 20), and the formula (IX):
OCN-X-NCO (IX)
(Wherein X is a divalent organic group) is obtained by reacting with diisocyanates.

  X of the diisocyanates represented by the above formula (IX) is, for example, a phenylene group substituted with an alkylene group having 1 to 20 carbon atoms, or an unsubstituted or lower alkyl group having 1 to 5 carbon atoms such as a methyl group. And arylene groups such as alicyclic alkylene groups. The number of carbon atoms of the alkylene group is more preferably 1-18. A group having two aromatic rings such as diphenylmethane-4,4′-diyl group and diphenylsulfone-4,4′-diyl group is also preferable.

  Examples of the carbonate diols represented by the above formula (VIII) include α, ω-poly (hexamethylene carbonate) diol, α, ω-poly (3-methyl-pentamethylene carbonate) diol, and the like. Examples of such products include trade names manufactured by Daicel Chemical Industries, Ltd .: PLACEL, CD-205, 205PL, 205HL, 210, 210PL, 210HL, 220, 220PL, 220HL, and the like. These can be used alone or in combination of two or more.

  Examples of the diisocyanates represented by the above formula (IX) include diphenylmethane-2,4'-diisocyanate; 3,2'-, 3,3'-, 4,2'-, 4,3'-, 5,2'-, 5,3'-, 6,2'- or 6,3'-dimethyldiphenylmethane-2,4'-diisocyanate; 3,2'-, 3,3'-, 4,2'- 4,3'-, 5,2'-, 5,3'-, 6,2'- or 6,3'-diethyldiphenylmethane-2,4'-diisocyanate; 3,2'-, 3,3 ' -, 4,2'-, 4,3'-, 5,2'-, 5,3'-, 6,2'- or 6,3'-dimethoxydiphenylmethane-2,4'-diisocyanate; diphenylmethane-4 , 4'-diisocyanate; diphenylmethane-3,3'-diisocyanate; diphenyl Diphenyl ether-4,4'-diisocyanate; benzophenone-4,4'-diisocyanate; diphenylsulfone-4,4'-diisocyanate; tolylene-2,4-diisocyanate; tolylene-2,6 -Diisocyanate; m-xylylene diisocyanate; p-xylylene diisocyanate; naphthalene-2,6-diisocyanate; 4,4 '-[2,2bis (4-phenoxyphenyl) propane] diisocyanate. In these diisocyanates, it is preferable to use an aromatic polyisocyanate in which X in the formula (IX) has an aromatic ring. These can be used alone or in combination of two or more.

  Further, as the diisocyanates represented by the formula (IX), within the scope of the object of the present invention, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, Aliphatic or alicyclic isocyanates such as transcyclohexane-1,4-diisocyanate, hydrogenated m-xylylene diisocyanate, and lysine diisocyanate, or trifunctional or higher polyisocyanates can be used. As the diisocyanate represented by the formula (IX), a diisocyanate stabilized with a blocking agent necessary for avoiding aging may be used. Examples of the blocking agent include alcohol, phenol and oxime, but there is no particular limitation.

  The mixing ratio of the carbonate diols represented by the above formula (VI) and the diisocyanates represented by the formula (IX) is such that the ratio of the number of hydroxyl groups to the number of isocyanate groups is isocyanate group / hydroxyl group = 1.01 or more. It is preferable to do.

  The reaction between the carbonate diols represented by the above formula (VIII) and the diisocyanates represented by the formula (IX) can be carried out without solvent or in the presence of an organic solvent. The reaction temperature is preferably 60 to 200 ° C, more preferably 80 to 180 ° C. The reaction time can be appropriately selected depending on the scale of the batch, the reaction conditions employed, and the like. For example, it can be 2 to 5 hours on a flask scale of 1 to 5 L (liter).

  The number average molecular weight of the isocyanate compound of the compound (b-1) thus obtained is preferably 500 to 10,000, more preferably 1,000 to 9,500, and 1,500 to Particularly preferred is 9,000. When the number average molecular weight is less than 500, the warpage tends to deteriorate, and when it exceeds 10,000, the reactivity of the isocyanate compound tends to decrease.

  In the present specification, the number average molecular weight is a value measured by gel permeation chromatography (GPC) and converted using a standard polystyrene calibration curve. Moreover, the number average molecular weight and dispersion degree of this invention are defined as follows.

a) Number average molecular weight (M _n )

b) Weight average molecular weight

ｃ）分子量分布（分散度）
分散度＝Ｍ_ｗ／Ｍ_ｎ

c) Molecular weight distribution (dispersity)
Dispersity = M _w / M _n

  As the isocyanate compound of component (b), a compound other than compound (b-1) (hereinafter referred to as compound (b-2)) can also be used. The compound (b-2) is not particularly limited as long as it is an isocyanate compound other than the compound (b-1), and examples thereof include diisocyanates represented by the formula (IX), trivalent or higher polyisocyanates, and the like. . These can be used alone or in combination of two or more. A preferred range of the number average molecular weight of the isocyanate compound of the compound (b-2) is the same as that of the compound (b-1).

  In particular, from the viewpoint of heat resistance, it is preferable to use the compound (b-1) and the compound (b-2) in combination. In addition, when using a compound (b-1) and a compound (b-2) each independently, a compound (b-1) is used from points, such as a softness | flexibility as a protective film for flexible substrates, and curvature. It is preferable.

  As compound (b-2), 50 to 100% by weight of the total amount is preferably aromatic polyisocyanate, and considering the balance of heat resistance, solubility, mechanical properties, cost, etc., 4, 4 '-Diphenylmethane diisocyanate is particularly preferred.

  When the compound (b-1) and the compound (b-2) are used in combination, the equivalent ratio of compound (b-1) / compound (b-2) is 0.1 / 0.9 to 0.9 / 0.1. Is preferable, 0.2 / 0.8 to 0.8 / 0.2 is more preferable, and 0.3 / 0.7 to 0.7 / 0.3 is particularly preferable. When the equivalence ratio is within this range, film properties such as good warpage, adhesion and good heat resistance can be obtained.

  Among the components (b), examples of the amine compound include compounds obtained by converting the isocyanate group in the isocyanate compound of the component (b) to an amino group. Conversion of the isocyanato group to an amino group can be performed by a known method. The preferred range of the number average molecular weight of the amine compound is the same as that of the above compound (b-1).

  In addition, the blending ratio of the trivalent polycarboxylic acid having an acid anhydride group of the component (a) or a derivative thereof and / or the tetravalent polycarboxylic acid having an acid anhydride group is the isocyanate group in the component (b). Preferably, the ratio of the total number of carboxyl groups and acid anhydride groups in component (a) to the total number of is 0.6 to 1.4, preferably 0.7 to 1.3. It is more preferable that the ratio is 0.8 to 1.2. When this ratio is less than 0.6 or exceeds 1.4, it tends to be difficult to increase the molecular weight of the resin containing polyimide bonds.

  When the compound represented by formula (I) is used as the component (a) and the compound (b-1) is used as the component (b), the following formula (X):

（式中、Ｒ、Ｘ、ｍ、ｎは、上記で定義した通りである。）で示される繰り返し単位を有するポリアミドイミド樹脂を得ることができる。

(Wherein, R, X, m, and n are as defined above) can be obtained.

  When the compound represented by the above formula (IV) is used as the component (a) and the compound (b-1) is used as the component (b), the following formula (XI):

（式中、Ｒ、Ｘ、ｍ、ｎ、Ｙ^２は、上記で定義した通りである。）で示される繰り返し単位を有するポリアミドイミド樹脂を得ることができる。

(Wherein R, X, m, n, and Y ² are as defined above) can be obtained.

  When the compound represented by the formula (V) is used as the component (a) and the compound (b-1) is used as the component (b), the following formula (XII):

（式中、Ｒ、Ｘ、ｍ、ｎ、Ｙ^２は、上記で定義した通りである。）で示される繰り返し単位を有するポリイミド樹脂を得ることができる。

(Wherein R, X, m, n, and Y ² are as defined above) can be obtained.

  In the present invention, (a) a trivalent polycarboxylic acid having an acid anhydride group and a derivative thereof, and a tetravalent having an acid anhydride group in the process for producing a resin containing an imide bond used as the component (A). The reaction between one or more compounds selected from polycarboxylic acids and (b) an isocyanate compound or an amine compound is carried out by using a carbon dioxide gas generated free in the presence of an organic solvent, preferably a non-nitrogen-containing polar solvent. It can be carried out by heat condensation while removing from the reaction system.

  Examples of the non-nitrogen-containing polar solvent include ether solvents such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether; sulfur-containing solvents such as dimethyl sulfoxide, diethyl sulfoxide, dimethyl sulfone, Sulfolane; ester solvents such as γ-butyrolactone, cellosolve acetate; ketone solvents such as cyclohexanone, methyl ethyl ketone; aromatic hydrocarbon solvents such as toluene, xylene, etc., which may be used alone or in combination of two or more. Can be used in combination.

  It is preferable to select and use a solvent that dissolves the resulting resin. After the synthesis, it is preferable to use a suitable paste solvent as it is. Γ-Butyrolactone is the most preferable because it is highly volatile, can impart low-temperature curability, and reacts efficiently in a homogeneous system. It is preferable that the usage-amount of a solvent shall be 0.8 to 5.0 times (weight ratio) of resin containing the imide bond to produce | generate. If it is less than 0.8 times, the viscosity at the time of synthesis is too high, and the synthesis tends to be difficult due to the inability to stir. If it exceeds 5.0 times, the reaction rate tends to decrease.

  The reaction temperature is preferably 80 to 210 ° C, more preferably 100 to 190 ° C, and particularly preferably 120 to 180 ° C. If it is less than 80 ° C., the reaction time becomes too long, and if it exceeds 210 ° C., a three-dimensional reaction occurs during the reaction and gelation tends to occur. The reaction time can be appropriately selected depending on the scale of the batch and the reaction conditions employed.

  If necessary, the reaction may be performed in the presence of a catalyst such as a tertiary amine, an alkali metal, an alkaline earth metal, a metal such as tin, zinc, titanium, cobalt, or a metalloid compound.

  The resin obtained as described above has an isocyanate residue. By blocking the isocyanate residue with the compound of the general formula (I) and / or the general formula (II), (B) The reactivity with the epoxy resin as a component is improved, and the adhesive force between the anisotropic conductive film and the flexible substrate under moisture absorption treatment conditions can be improved. In addition to the compounds of the general formula (I) and / or the general formula (II), blocking agents such as alcohols, lactams and oximes can be used in combination so as not to impair the effects of the present invention.

  As the compound of the general formula (I) and / or the general formula (II), pyromellitic anhydride represented by the following formula (XIII) which is a tetracarboxylic dianhydride is preferable.

  The number average molecular weight of the resin thus obtained is preferably 4,000 to 40,000, more preferably 5,000 to 38,000, and 6,000 to 36,000. It is particularly preferred that the degree of dispersion at that time is preferably 1.5 to 3.5, more preferably 2.0 to 3.0. When the number average molecular weight is less than 4,000, film properties such as heat resistance tend to be deteriorated and sticking to the polyimide film tends to occur. When the number average molecular weight exceeds 40,000, the viscosity of the resin is increased. It becomes high and there exists a tendency for workability | operativity, such as a mixing property of an inorganic filler and screen printing, to fall.

[(B) component: epoxy resin]
The thermosetting resin composition of the present invention contains an epoxy resin (hereinafter referred to as (B) component) in order to improve thermosetting. As the epoxy resin, for example, bisphenol A type epoxy resin (trade name: Epicoat 828 manufactured by Yuka Shell Epoxy Co., Ltd.), bisphenol F type epoxy resin (trade name manufactured by Toto Kasei Co., Ltd .: YDF-170, etc.), Phenol novolac type epoxy resin (Oilized Shell Epoxy Co., Ltd. trade name: Epicoat 152, 154; Nippon Kayaku Co., Ltd. trade name: EPPN-201; Dow Chemical Co., Ltd. trade name: DEN-438) o-cresol novolac type epoxy resin (trade names manufactured by Nippon Kayaku Co., Ltd .: EOCN-125S, 103S, 104S, etc.), multifunctional epoxy resins (trade names manufactured by Yuka Shell Epoxy Co., Ltd .: Epon 1031S; Ciba Specialty Product name made by Chemicals Co., Ltd .: Araldite 0163; Nagase Trade name: Denacol EX-611, EX-614, EX-614B, EX-622, EX-512, EX-521, EX-421, EX-411, EX-321, etc.), amine type epoxy resin (Product name manufactured by Yuka Shell Epoxy Co., Ltd .: Epicoat 604; Product name manufactured by Tohto Kasei Co., Ltd .: YH434; Product names manufactured by Mitsubishi Gas Chemical Co., Ltd .: TETRAD-X, TERRAD-C; manufactured by Nippon Kayaku Co., Ltd. Trade name: GAN; trade name: ELM-120 manufactured by Sumitomo Chemical Co., Ltd.), heterocyclic-containing epoxy resin (trade name: Araldite PT810 manufactured by Ciba Specialty Chemicals Co., Ltd.), alicyclic epoxy resin ( UCC brand name: ERL4234, 4299, 4221, 4206, etc.) and the like. In combination can be used.

  Among these epoxy resins, amine-type epoxy resins having 3 or more epoxy groups in one molecule are particularly preferable in terms of improving solvent resistance, chemical resistance, and moisture resistance.

  These epoxy resins may contain an epoxy compound having only one epoxy group in one molecule. Such an epoxy compound is preferably used in the range of 0 to 20% by weight based on the total amount of the resin as the component (A). Examples of such an epoxy compound include n-butyl glycidyl ether, phenyl glycidyl ether, dibromophenyl glycidyl ether, and dibromocresyl glycidyl ether. In addition, alicyclic epoxy compounds such as 3,4-epoxycyclohexyl and methyl (3,4-epoxycyclohexane) carboxylate can be used.

  The content of these epoxy resins is preferably 15 to 50 parts by mass, more preferably 20 to 45 parts by mass, and more preferably 25 to 40 parts by mass with respect to 100 parts by mass of the resin (A). It is particularly preferred. When the content of the epoxy resin is less than 15 parts by mass, the PCT resistance and moisture-proof insulation reliability tend to decrease, and when it exceeds 50 parts by weight, the heat resistance and viscosity stability tend to decrease.

  As an addition method of the epoxy resin, the epoxy resin to be added may be added after being dissolved in the same organic solvent as the component (A) that dissolves the resin containing an imide bond, or added directly. May be.

[(C) component: inorganic filler]
The inorganic filler in the present invention (hereinafter referred to as “component (C)”) contains aluminum hydroxide having an average particle size of 1.5 to 10 μm (hereinafter referred to as “component (C1)”). Due to the presence of aluminum hydroxide, fine irregularities can be formed on the surface of the thermosetting resin composition, and further, there is an effect of reinforcing the mechanical strength of the surface of the thermosetting resin composition. As a result, the infiltration of water into the interface between the anisotropic conductive film and the solder resist is suppressed, and as a result, the adhesive force between the solder resist and the anisotropic conductive adhesive film is reduced under the moisture absorption treatment conditions assuming the condensation environment. The suppressing effect can be obtained.

  As the component (C1), it is preferable to use aluminum hydroxide having an average particle diameter of 1.5 to 10 μm, and further an average particle diameter of 1.5 to 5 μm. When the average particle size is less than 1.5 μm, fine unevenness is not sufficiently formed, and thus the adhesive force between the solder resist and the anisotropic conductive adhesive film under a moisture absorption process condition assuming a dew condensation environment is greatly reduced. On the other hand, if the average particle size exceeds 10 μm, the insulation reliability may be significantly lowered.

  The content of the aluminum hydroxide as the component (C1) is preferably 10 to 40 parts by weight, more preferably 15 to 30 parts by weight with respect to 100 parts by weight of the solid content of the component (A). If the content is less than 10 parts by weight, the effect of suppressing the ingress of water into the interface between the anisotropic conductive film and the solder resist is not sufficient, so the solder resist and the anisotropic conductive under the moisture absorption treatment conditions assuming the condensation environment The adhesive strength of the adhesive film is greatly reduced. On the other hand, if the content exceeds 40 parts by weight, the fluidity when the thermosetting resin composition is applied is lowered, and the appearance of the coated film after resist coating may be lowered or the insulation reliability may be lowered. is there.

In addition, other inorganic filler components can be used in combination with the aluminum hydroxide that is the component (C1). The inorganic filler component that can be used in combination is not particularly limited as long as it can be dispersed in the resin (A) or the epoxy resin (B) to form a resist ink. Examples of the inorganic filler include silica (SIO ₂ ), talc (3MgO · 4SIO ₂ · H ₂ O, alumina (Al ₂ O ₃ ), titania (TIO ₂ ), tantalum oxide (Ta ₂ O ₅ ), and zirconia (ZrO). ₂ ), silicon nitride (SI ₃ N ₄ ), barium titanate (BaO · TIO ₂ ), barium carbonate (BaCO ₃ ), lead titanate (PbO · TIO ₂ ), lead zirconate titanate (PZT), titanate Lead lanthanum zirconate (PLZT), gallium oxide (Ga ₂ O ₃ ), spinel (MgO · Al ₂ O ₃ ), mullite (3Al ₂ O ₃ · 2SIO ₂ ), cordierite (2MgO · 2Al ₂ O ₃ / 5SIO) _2), aluminum titanate _{(TIO 2} -Al _{2 O} 3), yttria-containing zirconia _{(Y 2} O 3 -ZrO ₂ ), Barium silicate (BaO · 8SIO ₂ ), boron nitride (BN), calcium carbonate (CaCO ₃ ), calcium sulfate (CaSO ₄ ), zinc oxide (ZnO), magnesium titanate (MgO · TIO ₂ ), barium sulfate (BaSO ₄ ), organic bentonite, carbon (C) and the like can be used, and one or more of these can also be used.

  When other inorganic filler components are used in combination with talc used as component (C), the total content of aluminum hydroxide and other inorganic filler components is (A) the acid anhydride group and / or carboxyl group. It is preferable that it is 250 weight part or less with respect to 100 weight part of solid content of resin which has this. When the content exceeds 250 parts by weight, the viscosity of the thermosetting resin composition becomes too high, and it becomes difficult to uniformly disperse the inorganic filler in the thermosetting resin composition. Insulation reliability may be reduced.

[(D) component: crosslinking agent]
The thermosetting resin composition of this invention can contain a crosslinking agent (henceforth (D) component). As the crosslinking agent which is component (D), a melamine resin compound which is a crosslinking agent for paints and has an effect of improving the hydrophobicity of the surface of the thermosetting resin composition can be used. As such a melamine resin compound, the brand names made by Mitsui Cytec Co., Ltd .: Cymel 300, Cymel 303, Cymel 325, etc. can be used.

  Further, the content of the crosslinking agent as the component (D) is preferably 1 to 15 parts by weight, more preferably 3 to 10 parts by weight with respect to 100 parts by weight of the solid content of the component (A). If the content is less than 1 part by weight, the surface of the thermosetting resin composition is low in hydrophobicity, and therefore prevents a decrease in the adhesive strength between the solder resist and the anisotropic conductive adhesive film under moisture absorption conditions assuming a condensation environment. There is a possibility that the effect cannot be obtained and sufficient insulation reliability cannot be secured. On the other hand, when the content exceeds 15 parts by weight, the storage stability of the thermosetting resin composition tends to be lowered.

[Other additive components]
Various additives can be added to the thermosetting resin composition of the present invention as necessary. For example, known colorants such as phthalocyanine blue, phthalocyanine green, iodine green, bisazo yellow, crystal violet, titanium oxide, carbon black, naphthalene black, hydroquinone, methyl hydroquinone, hydroquinone monomethyl ether, catechol, pyrogallol, etc. Polymerization inhibitors, surface modifiers such as oleic acid amide, stearic acid amide, erucic acid amide, various anti-foaming and leveling agents such as silicone, fluorine and vinyl resins, silanes, titanates and other coupling agents In addition, various known and commonly used additives such as epoxy curing agents such as block isocyanates, block acid catalysts and their dissociators, adhesion imparting agents, antioxidants, and pigment dispersants can be used.

[Flexible substrate]
The flexible substrate by this invention contains a flexible wiring board etc., and is manufactured using the thermosetting resin composition mentioned above. For example, a flexible wiring board (COF base material) used for COF mounting is a wiring that is connected to a rigid wiring board, a driver IC, an electronic component, or a liquid crystal panel as a motherboard on a polyimide film on which a conductor circuit pattern is formed. The above-described thermosetting resin composition layer (solder resist layer) is formed at a location excluding the pattern portion, and a predetermined thermosetting treatment is performed. Moreover, the thermosetting resin composition mentioned above is used as a protective film of the flexible printed circuit board which laminated | stacked copper foil on the polyimide base material. In particular, since the thermosetting resin composition of the present invention can be cured at a low temperature (80 ° C. to 140 ° C.), it is suitable for use as a protective film on the surface of a flexible wiring board on which a wiring pattern portion is plated. The conditions for thermosetting are preferably from 80 ° C to 140 ° C, more preferably from 90 ° C to 130 ° C, and from 100 ° C to 100 ° C from the viewpoint of preventing diffusion of the plating layer and obtaining suitable warpage and flexibility as a protective film. 120 ° C. is particularly preferred. The heating time is preferably 10 to 150 minutes, more preferably 30 to 120 minutes, and particularly preferably 40 to 110 minutes.

  In the reel-toe-reel method, the COF substrate is often wound up through a film-like spacer made of polyimide such as Kapton, but it is heated at a high temperature during the solder resist thermosetting process or the electronic component mounting process. When the COF substrate is wound up during the treatment (or immediately after the heat treatment), the spacer and the solder resist may stick. However, stickiness can be improved by using the thermosetting resin composition according to the present invention.

  Furthermore, in recent years, insulation reliability under high voltage is important in COF for digital home appliances, but sufficient insulation reliability can be obtained by using the thermosetting resin composition according to the present invention as a solder resist layer. can get.

[Electronic parts]
The electronic component according to the present invention includes various electronic components using the flexible substrate described above. In recent years, in the field of so-called digital home appliances such as plasma and liquid crystal flat-screen TVs, digital video cameras, DVD recorders, portable audio players, etc., which have rapidly spread in the market, it is necessary to respond to downsizing, thinning, and high functionality Therefore, it can be preferably used as an electronic component mounted in a narrow space with high density. Moreover, it can be preferably used as an electronic component mounted on various portable electronic devices such as a mobile phone, portable music, and an image reproducing device.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. In addition, this invention is not limited to a following example.

Synthesis Example of Resin (A-1) In a 5-liter four-necked flask equipped with a stirrer, a cooling tube with an oil / water separator, a nitrogen introduction tube and a thermometer, PLACEL CD-220 (1,6-manufactured by Daicel Chemical Industries, Ltd.) 900.0 g (0.45 mol) of hexanediol-based polycarbonate diol, 140.32 g (0.56 mol) of 4,4′-diphenylmethane diisocyanate and 70.72 g (0.40 mol) of tolylene diisocyanate Was charged with 738.31 g of γ-butyrolactone as an organic solvent, and the temperature was raised to 150 ° C. The reaction was carried out at 150 ° C. for 5 hours to obtain a diisocyanate compound represented by the general formula (III).

  The solution was cooled to 80 ° C., 105.6 g (0.55 mol) of trimellitic anhydride, 15.6 g (0.06 mol) of 4,4′-diphenylmethane diisocyanate as component (b-1), and tolylene diene. 7.86 g (0.04 mol) of isocyanate was charged and the temperature was raised to 180 ° C., followed by reaction for 6 hours. Next, the obtained solution was cooled to 80 ° C., 29.29 g (0.13 mol) of pyromellitic anhydride was charged with 501.78 g of γ-butyrolactone as an organic solvent, and reacted at 120 ° C. for 1 hour. A polyamideimide resin (A-1) having a molecular weight of about 32,000 and a solid content of 50% by weight was obtained.

Synthesis Example of Resin (A-2) PLACCEL CD-220 (1,6-manufactured by Daicel Chemical Industries, Ltd.) was added to a 5-liter four-necked flask equipped with a stirrer, a cooling tube with an oil / water separator, a nitrogen introduction tube and a thermometer. 700 g (0.35 mol) of hexanediol-based polycarbonate diol, 104.18 g (0.42 mol) of 4,4′-diphenylmethane diisocyanate, and 48.62 g (0.28 mol) of tolylene diisocyanate, As an organic solvent, 569 g of γ-butyrolactone was charged, and the temperature was raised to 150 ° C. Next, the obtained solution was reacted at 150 ° C. for 5 hours to obtain a diisocyanate compound represented by the general formula (III).

  This solution was cooled to 80 ° C., 124.51 g (0.65 mol) of trimellitic anhydride, 44.94 g (0.18 mol) of 4,4′-diphenylmethane diisocyanate as component (b-1), and tolylene 20.76 g (0.12 mol) of isocyanate was charged, and the temperature was raised to 170 ° C., followed by reaction for 6 hours. Next, the obtained solution was cooled to 80 ° C., 29.29 g (0.13 mol) of pyromellitic anhydride was charged with 276.56 g of γ-butyrolactone as an organic solvent, and reacted at 120 ° C. for 1 hour. A polyamideimide resin (A-2) having an average molecular weight of 30,000 and a solid content of 46% by weight was obtained.

  Using the polyamideimide resins ((A-1) and (A-2)) obtained as described above, according to the formulation (composition) shown in Table 1, six types of resin compositions corresponding to Examples 1 to 6 The product was made using a three roll mill.

(Comparative example) Synthetic example of resin (A-3) PLACEL CD-220 (manufactured by Daicel Chemical Industries, Ltd.) was added to a 5-liter four-necked flask equipped with a stirrer, a condenser tube with an oil / water separator, a nitrogen inlet tube and a thermometer. 900.0 g (0.45 mol) of 1,6-hexanediol-based polycarbonate diol, 140.32 g (0.56 mol) of 4,4′-diphenylmethane diisocyanate, and 70.72 g (0 of tolylene diisocyanate) .40 mol) was charged with 738.31 g of γ-butyrolactone as an organic solvent, and the temperature was raised to 150 ° C. Next, the obtained solution was reacted at 150 ° C. for 5 hours to obtain a diisocyanate compound represented by the general formula (III).

  This solution was cooled to 80 ° C., 105.6 g (0.55 mol) of trimellitic anhydride, 15.6 g (0.06 mol) of 4,4′-diphenylmethane diisocyanate as component (b-1), and tolylene 7.86 g (0.04 mol) of isocyanate was charged and the temperature was raised to 180 ° C., followed by reaction for 6 hours. Next, the obtained solution was cooled to 80 ° C., and 2-butanone oxime; 11.3 g (0.13 mol) was used for the purpose of blocking the isocyanate group at the molecular end, and 501.78 g of γ-butyrolactone as an organic solvent. Was reacted at 95 ° C. for 2 hours to obtain a polyamideimide resin (A-3) having a number average molecular weight of about 29,000 and a solid content of 50% by weight.

  Using the resin (A-3) obtained as described above and the resin (A-1) used in Examples, according to the formulation (composition) shown in Table 1, three types corresponding to Comparative Examples 1 to 3 were used. The resin composition was produced using a three roll mill.

表中、＊１：ジャパンエポキシレジン株式会社製商品名、＊２：東都化成株式会社製商
品名、＊３：住友化学工業株式会社製商品名、＊４：日本軽金属株式会社製商品名、＊５昭和電工株式会社製商品名、＊６：山陽色素株式会社製商品名、＊７：信越シリコーン株式会社製商品名、＊８：東亜合成株式会社製商品名、＊９：住友バイエルウレタン株式会社製商品名、＊１０：三井サイテック株式会社製商品名

* 1: Product name made by Japan Epoxy Resin Co., Ltd. * 2: Product name made by Toto Kasei Co., Ltd. * 3: Product name made by Sumitomo Chemical Co., Ltd. * 4: Product name made by Nippon Light Metal Co., Ltd. * 5 Product name manufactured by Showa Denko KK * 6: Product name manufactured by Sanyo Dye Co., Ltd. * 7: Product name manufactured by Shin-Etsu Silicone Co., Ltd. * 8: Product name manufactured by Toa Gosei Co., Ltd. * 9: Sumitomo Bayer Urethane Co., Ltd. Product name * 10: Product name manufactured by Mitsui Cytec Co., Ltd.

  The characteristics of the thermosetting resin compositions (resist ink compositions) of Examples 1 to 6 and Comparative Examples 1 to 3 were evaluated by the following items.

Adhesiveness with anisotropic conductive film A sample for evaluating adhesiveness was prepared and evaluated by the following method.
(1) As shown in FIG. 1, a metalizing two-layer base material in which a conductor circuit 1 (a copper circuit surface layer is tin-plated) with a pitch distance of 30 μm (line / space = 10 μm / 20 μm) is formed. The film thickness after drying the thermosetting resin composition (solder resist layer) 3 at a predetermined location on a certain polyimide substrate 2 (COF substrate, Esperflex-S: trade name, manufactured by Sumitomo Metal Mining Co., Ltd.) It apply | coated so that it might become 10 micrometers.

(2) Next, a heat curing treatment at 120 ° C./60 minutes was performed to prepare a cured resist film.
(3) Using a crimping machine, an anisotropic conductive film (AC-7246, product name, manufactured by Hitachi Chemical Co., Ltd.) having a thickness of 15 μm and a width of 1.5 mm is pressure 1 MPa so that the temperature on the film becomes 80 ° C. Then, it was temporarily pressure-bonded onto a glass plate under the condition of a pressure-bonding time of 5 seconds.

(4) Next, main pressure bonding of the anisotropic conductive film 4 and the polyimide base material 2 (COF base material) is performed by the method shown in FIG. That is, using a crimping machine, the polyimide substrate 2 (with the anisotropic conductive film 4 interposed on the glass plate 5 under the conditions of a pressure of 3 MPa and a crimping time of 15 seconds so that the temperature on the film becomes 180 ° C. COF base material) was press-bonded.

(5) The COF substrate was peeled off in the 90 ° direction using an autograph (Tensilon, manufactured by Shimadzu Corporation), and the adhesion strength between the COF substrate and the anisotropic conductive film was evaluated. The evaluation was carried out for the adhesive strength after standing for 500 hours in a constant temperature and humidity chamber maintained in a normal state and an environment of 65 ° C./95%. The evaluation of the adhesive strength was performed with n = 5, and the value was expressed as an average value of n = 5.

Warpage characteristics (1) A thermosetting resin composition obtained as described above on a polyimide film (Kapton 100H: trade name, manufactured by Nippon Steel Chemical Co., Ltd.) having a thickness of 25 μm and a size of 50 mm × 50 mm. One side was coated so that the film thickness after drying was 10 μm.
(2) Hereafter, the thermosetting process similar to the sample for adhesive evaluation with an anisotropic conductive film was implemented, the resist cured film was produced, and the curvature amount after a thermosetting process was evaluated. For the evaluation of the amount of warpage, the average of the lifts at the four apexes when the central portion of the polyimide film was fixed was calculated. The evaluation of warpage was performed at n = 5, and the value was expressed as an average value of n = 5.

Folding resistance (1) Evaluation was carried out using a cured resist film produced by the same method as the sample for evaluating adhesiveness with an anisotropic conductive film. This was performed by 135 ° facing bending in accordance with JIS P 8115, and the number of bendings until the circuit was disconnected was evaluated.

Electric corrosion resistance (1) Metalizing two-layer base material (Esperflex-S) on which a comb-shaped conductor circuit (copper circuit surface plated with tin) with a pitch distance of 30 μm (line / space = 10 μm / 20 μm) is formed : Product name of Sumitomo Metal Mining Co., Ltd.) was applied so that the film thickness after drying was 10 μm.
(2) Hereafter, the sample was produced by performing the thermosetting process similar to the sample for adhesive evaluation with an anisotropic conductive film. The evaluation was performed by applying a voltage of 40 V continuously for 500 hours in a constant temperature and humidity chamber maintained in an environment of 65 ° C./95%, and examining the change in the insulation resistance value between the circuits. When the insulation resistance value between the circuits was less than the eighth power order, it was determined that the insulation was poor (insufficient electric corrosion resistance: x).

PCT (Pressure Cooker Test) Resistance Evaluation was carried out using a cured resist film produced by the same method as the sample for adhesion evaluation with an anisotropic conductive film. The evaluation was performed by performing a moisture absorption treatment for 100 hours under the conditions of 121 ° C./100%/2.3 atm, and visually observing the presence or absence of swelling and peeling of the cured resist film.

Adhesion Evaluation was carried out using a cured resist film produced by the same method as the sample for evaluating adhesion to an anisotropic conductive film. The evaluation was performed by a cross-cut method based on JIS K 5400. A summary of the above evaluation results is shown in Table 2.

  In the evaluation samples in Comparative Examples 1 to 3, the adhesive strength between the solder resist and the anisotropic conductive adhesive film under the moisture absorption treatment condition was greatly reduced. Moreover, in Comparative Examples 1-3, the adhesive strength after a moisture absorption process fell very much.

  In contrast, in Examples 1 to 6, the adhesive strength between the solder resist and the anisotropic conductive adhesive film under the moisture absorption treatment condition was maintained, and the decrease rate of the adhesive strength after the moisture absorption treatment was low. Furthermore, the electrolytic corrosion resistance was also a good evaluation result. Therefore, it was revealed that a thermosetting resin composition having a good adhesive force with the anisotropic conductive adhesive film was obtained even under moisture absorption conditions assuming a condensation environment.

  In the conventional polyamideimide resin composition for COF-mounting flexible substrates, reduction in the adhesive strength between the solder resist and the anisotropic conductive adhesive film under the moisture absorption treatment conditions assuming the dew condensation environment has been an issue. Thus, a thermosetting resin composition having a good adhesive force with the anisotropic conductive adhesive film can be obtained even under moisture absorption treatment conditions assuming a dew condensation environment. Therefore, the thermosetting resin composition according to the present invention and a flexible substrate using the same are useful for various applications such as solder resist, printed wiring boards, interlayer insulating materials in electronic parts such as semiconductor applications, and laminated boards.

It is a schematic plan view which shows the sample for evaluation in the Example of this invention. It is a fragmentary sectional side view which shows the sample for evaluation in the Example of this invention.

Explanation of symbols

1 Conductor circuit 2 Polyimide substrate (COF substrate)
3 Thermosetting resin composition (solder resist layer)
4 Anisotropic conductive film 5 Glass plate

Claims (9)

  (A) A thermosetting resin composition comprising a resin having an acid anhydride group and / or a carboxyl group, (B) an epoxy resin, and (C) an inorganic filler, wherein the (C) inorganic A thermosetting resin composition comprising (C1) aluminum hydroxide having an average particle diameter of 1.5 to 10 μm as a filler.   (A) Resin which has an acid anhydride group and / or a carboxyl group is resin which has a urethane bond, The thermosetting resin composition of Claim 1 characterized by the above-mentioned.   (A) Resin which has an acid anhydride group and / or a carboxyl group has a polycarbonate frame | skeleton, The thermosetting resin composition of Claim 1 or Claim 2 characterized by the above-mentioned.   (B) Content of an epoxy resin is 15-50 weight part with respect to 100 weight part of (A) resin which has an acid anhydride group and / or a carboxyl group, The Claim 1 to Claims characterized by the above-mentioned. 3. The thermosetting resin composition according to claim 1.   The content of (C1) aluminum hydroxide is 10 to 40 parts by weight with respect to 100 parts by weight of the resin (A) having an acid anhydride group and / or carboxyl group. Item 5. The thermosetting resin composition according to any one of Items 4.   (D) The thermosetting resin composition according to any one of claims 1 to 5, further comprising a crosslinking agent.   It is used as a protective film of the flexible printed circuit board which laminated | stacked copper foil on the polyimide base material, The thermosetting resin composition of any one of Claims 1-6 characterized by the above-mentioned.   A flexible substrate comprising the thermosetting resin composition according to any one of claims 1 to 7.   An electronic component comprising the flexible substrate according to claim 8.

Images