JP4937555B2 - Solder resist resin composition, method for producing the same, and cured product thereof - Google Patents

Description

  The present invention relates to a solder resist resin composition for pre-tin plating and a cured product excellent in electrical insulation obtained using the same.

  In recent years, in the field of electronic parts, polyimide resin or polyamide-imide resin has been used instead of epoxy resin as a resin with excellent heat resistance, chemical resistance and moisture resistance in response to miniaturization, thinning and high speed. Has been. For example, Japanese Patent Application Laid-Open No. 2002-145981, Japanese Patent Application Laid-Open No. 2003-198105, and Japanese Patent Application Laid-Open No. 2003-335944 are soluble in a non-nitrogen-based polar solvent and have low warpage and flexibility. An imide resin is disclosed. These polyimide resins or polyamide-imide resins show good results in tests such as adhesion to the sealing material, solvent resistance, chemical resistance (solder flux resistance), and moisture resistance.

However, in recent years, the fine pitch of electronic component wiring has progressed, and particularly with respect to a solder resist for pre-tin plating of a flexible substrate, there has been a problem that conventional products lack the electrical insulation reliability of the coating. Here, pre-tin plating means that tin plating is performed before forming a solder resist layer on the wiring pattern formed on the substrate in order to improve the antioxidant performance of the substrate or to improve the adhesion between the solder resist and the substrate, and then This means that solder resist is applied.
JP 2002-145981 A JP 2003-198105 A JP 2003-335944 A

  The present invention solves the above-mentioned problems of the prior art, has a low warpage property, a solvent resistance, and a resin composition that makes it possible to produce a solder resist for pre-tin plating excellent in electrical insulation, and The purpose is to provide the cured product used.

  Furthermore, this invention aims at providing the method of manufacturing the above resin compositions.

  As a result of investigations to solve the above problems, the present inventors have found that the balance between hydrophilicity and hydrophobicity of the solder resist coating for pre-tin plating affects the electrical insulation, that is, the carbon of the resin raw material used. Based on this finding, the solder resist resin composition for pre-tin plating, which can obtain a solder resist excellent in electrical insulation, in addition to the conventional characteristics, was used. The cured product was found and the present invention was completed.

  The solder resist resin composition for tin plating of the present invention is characterized by containing a resin having a repeating unit represented by the following general formula (I).

  In the above formula (I), a plurality of R's each independently represents an alkylene group having 8 to 9 carbon atoms which may be branched, and a plurality of X's are each independently an alkylene having 2 to 18 carbon atoms. A group or an arylene group, m and n each independently represent an integer of 1 to 20, and Y represents a tetravalent organic group.

  Moreover, the manufacturing method of the solder resist resin composition for the tin-plating of this invention consists of (a) tetravalent polycarboxylic acid which has an acid anhydride group, (b) diisocyanate represented by general formula (II), and (c ) A polyisocyanate compound is reacted to produce a resin having a repeating unit represented by the following general formula (I), which is used.

上記式（Ｉ）において、複数個のＲは、それぞれ独立に、分岐しても良い炭素数８〜９のアルキレン基を示し、複数個のＸは、それぞれ独立に、炭素数２〜１８のアルキレン基又はアリーレン基を示し、ｍ及びｎは、それぞれ独立に、１〜２０の整数を示し、Ｙは４価の有機基を示す。
In the above formula (II), a plurality of R's each independently represents an alkylene group having 8 to 9 carbon atoms which may be branched, and a plurality of X's each independently represents an alkylene group having 2 to 18 carbon atoms. A group or an arylene group, and m and n each independently represent an integer of 1 to 20.

In the above formula (I), a plurality of R's each independently represents an alkylene group having 8 to 9 carbon atoms which may be branched, and a plurality of X's are each independently an alkylene having 2 to 18 carbon atoms. A group or an arylene group, m and n each independently represent an integer of 1 to 20, and Y represents a tetravalent organic group.

  Furthermore, the cured body of the soldering resist composition for pre-plating of the present invention is formed by curing the above resin composition.

  If the solder resist composition for pretin plating of this invention is used, in addition to the conventional characteristic, the solder resist hardened | cured material for pretin plating excellent in electrical insulation will be obtained.

Hereinafter, the present invention will be described in more detail.
The resin composition of the present invention (I) contains the polyimide resin as the component (A) as described above.
The (A) component polyimide resin is preferably obtained by reacting (a) a tetravalent polycarboxylic acid having an acid anhydride group and (b) a diisocyanate represented by the general formula (II) as essential components. . In the general formula (I), Y is a tetravalent organic group, but is generally a residue of a tetravalent tetracarboxylic dianhydride that reacts with an isocyanate compound or an amine compound to form an imide structure.

  Although there is no restriction | limiting in particular as tetravalent polycarboxylic acid which has an acid anhydride group used as (a) component for manufacture of the polyimide resin of (A) component in this invention, For example, general formula (III)

 (Where Y is

Represents a tetravalent group selected from ) Tetracarboxylic dianhydride represented by These can be used alone or in combination of two or more.
In addition to the above tetracarboxylic dianhydrides, aliphatic dicarboxylic acids (eg, succinic acid, glutanic acid, adipic acid, azelaic acid, suberic acid, sebacic acid, decanedioic acid, dodecanedioic acid) , Dimer acids, etc.), aromatic dicarboxylic acids (eg, isophthalic acid, terephthalic acid, phthalic acid, naphthalenedicarboxylic acid, oxydibenzoic acid, etc.), trivalent tricarboxylic acids having acid anhydride groups (eg, trimellitic anhydride) Products, trimellitic anhydride monoester, etc.).

In the present invention, the diisocyanate represented by the general formula (II) used as the component (b) is, for example, a carbonate diol represented by the general formula (IV).

(Wherein a plurality of R's each represent an alkylene group having 8 to 9 carbon atoms which may be independently branched, and m is an integer of 2 to 20);

Diisocyanates OCN-X-NCO represented by general formula (V) (V)
(In the formula, X is preferably an arylene group having 6 to 30 carbon atoms such as an alkylene group having 2 to 18 carbon atoms or a phenylene group (this is a lower alkyl group having 1 to 5 carbon atoms such as a methyl group as a substituent). It is obtained by reacting in a solvent-free or organic solvent.

  Examples of the carbonate diols represented by the above general formula (IV) include those commercially available as trade names Kuraray Polyol C-1015N, C-1065N, C-2015N, C-2065N manufactured by Kuraray Co., Ltd. These may be used alone or in combination of two or more.

  Examples of the diisocyanates represented by the general formula (V) include diphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4,2'- or 4,3'-. Or 5,2'- or 5,3'- or 6,2'- or 6,3'-dimethyldiphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4,2 ' -Or 4,3'- or 5,2'- or 5,3'- or 6,2'- or 6,3'-diethyldiphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3 '-Or 4,2'- or 4,3'- or 5,2'- or 5,3'- or 6,2'- or 6,3'-dimethoxydiphenylmethane-2,4'-diisocyanate, diphenylmethane- 4,4'-diisocyanate, diphenylmethane-3 3'-diisocyanate, diphenylmethane-3,4'-diisocyanate, diphenyl ether-4,4'-diisocyanate, benzophenone-4,4'-diisocyanate, diphenylsulfone-4,4'-diisocyanate, tolylene-2,4-diisocyanate, Such as tolylene-2,6-diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, naphthalene-2,6-diisocyanate, 4,4 '-[2,2-bis (4-phenoxyphenyl) propane] diisocyanate Preference is given to using aromatic polyisocyanates. These can be used alone or in combination of two or more. Hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, transcyclohexane-1,4-diisocyanate, hydrogenated m-xylylene diisocyanate, lysine diisocyanate, etc. Aliphatic or alicyclic isocyanates and tri- or higher functional polyisocyanates may be used, and those stabilized with a blocking agent necessary to avoid changes over time may be used. Examples of the blocking agent include alcohol, phenol and oxime, but there is no particular limitation.

The blending amount of the carbonate diols represented by the general formula (V) and the diisocyanates represented by the general formula (V) is such that the ratio of the number of hydroxyl groups to the number of isocyanate groups is isocyanate group / hydroxyl group = 1.01. It is preferable to make it above.

  The reaction can be carried out without solvent or in the presence of an organic solvent. The reaction temperature is preferably 60 to 200 ° C., and the reaction time can be appropriately selected depending on the scale of the batch, the reaction conditions employed, and the like.

  The number average molecular weight of the diisocyanate as the component (b) thus obtained is preferably 1,000 to 10,000, more preferably 1,200 to 9,500, and 1,500 to 9 Is particularly preferred. If the number average molecular weight is less than 1,000, the warping property tends to deteriorate. If the number average molecular weight exceeds 10,000, the reactivity of the diisocyanate decreases, making it difficult to make a polyimide resin or a polyamideimide resin. Tend to be.

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.
In the present invention, it is preferable from the viewpoint of heat resistance to use a polyisocyanate compound other than the component (b) as the component (c). Such a polyisocyanate compound is not particularly limited, and examples thereof include diisocyanates represented by the general formula (VI) used in the component (b) or triisocyanate or higher polyisocyanates alone or in combination of two or more. Can be used in combination.

As the polyisocyanate compound of component (c), 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 4,4'-diphenylmethane diisocyanate and tolylene diisocyanate are particularly preferred.

  In the present invention, the blending ratio of the diisocyanate represented by the general formula (II) of the component (b) and the polyisocyanate compound of the component (c) is 0.1 / 0 in terms of the equivalent ratio of the component (b) / (c). 0.9 to 0.9 / 0.1, more preferably 0.2 / 0.8 to 0.8 / 0.2, and 0.3 / 0.7 to 0.7 / A value of 0.3 is particularly preferable. If the equivalent ratio is less than 0.1 / 0.9, the elastic modulus cannot be lowered, and the warpage and adhesion tend to decrease. If the equivalent ratio exceeds 0.9 / 0.1, film properties such as heat resistance can be obtained. Tends to decrease.

  In addition, the blending ratio of the (a) component tetravalent polycarboxylic acid having an acid anhydride group and the trivalent aromatic polycarboxylic acid having an acid anhydride is as follows in the components (b) and (c): The ratio of the total number of acid anhydride groups and carboxylic acid groups of component (a) to the total number of isocyanate groups is preferably 0.6 to 1.4, more preferably 0.7 to 1.3, and more preferably 0. .8 to 1.2. If this ratio is less than 0.6 or exceeds 1.4, it tends to be difficult to increase the molecular weight of the resin.

The reaction in the process for producing the resin used in the present invention is carried out by heat condensation in the presence of an organic solvent, preferably a non-nitrogen-containing polar solvent, while removing the liberated carbon dioxide gas from the reaction system. Can do. 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, and triethylene glycol diethyl ether; sulfur-containing solvents such as dimethyl sulfoxide, diethyl sulfoxide, dimethyl sulfone, sulfolane; ester solvents, for example, .gamma.-butyrolactone, etc. cellosolve acetate; ketone solvents such as cyclohexanone, methyl ethyl ketone and the like, which may be used alone or in combination of two or more. It is preferable to select and use a solvent that dissolves the resin to be formed. After the synthesis, it is preferable to use a suitable paste solvent as it is. In order to carry out the reaction in a homogeneous system with high volatility and low temperature curability, γ-butyrolactone or cellosolve acetate is preferred.

  The amount of the solvent used is preferably 0.8 to 5.0 times (weight ratio) of the resin to be produced. 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 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. When the number average molecular weight is less than 4,000, film properties such as heat resistance tend to be lowered. When the number average molecular weight is more than 40,000, it is difficult to dissolve in a non-nitrogen-containing polar solvent and easily insolubilizes during synthesis. . In addition, workability tends to be inferior.

In addition, the isocyanate group at the end of the resin can be blocked with a blocking agent such as alcohols, lactams, or oximes after completion of the synthesis.
Examples of the epoxy resin of component (B) used in the present invention include bisphenol A type epoxy resins such as trade name Epicoat 828 manufactured by Yuka Shell Epoxy Co., Ltd., and trade name YDF-170 manufactured by Tohto Kasei Co., Ltd. Such as bisphenol F type epoxy resin, product name Epicoat 152, 154 manufactured by Yuka Shell Epoxy Co., Ltd., product name EPPN-201 manufactured by Nippon Kayaku Co., Ltd., and product name DEN-438 manufactured by Dow Chemical Co., Ltd. Phenol novolac type epoxy resins, Nippon Kayaku Co., Ltd. EOCN-125S, 103S, 104S and other o-cresol novolac type epoxy resins, Yuka Shell Epoxy Co., Ltd. trade name Epon 1031S, Ciba Specialty Chemicals ( Trade name Araldite 0163, manufactured by Nagase Chemical Co., Ltd. 11, EX-614, EX-614B, EX-622, EX-512, EX-521, EX-421, EX-411, EX-311 and other polyfunctional epoxy resins, products manufactured by Yuka Shell Epoxy Co., Ltd. Name Epicoat 604, trade name YH-434 manufactured by Tohto Kasei Co., Ltd., trade names TETRAD-X and TETRAD-C manufactured by Mitsubishi Gas Chemical Co., Ltd., trade names GAN manufactured by Nippon Kayaku Co., Ltd., Sumitomo Chemical ( Amine type epoxy resins such as ELM-12 manufactured by Co., Ltd., epoxy resins containing heterocyclic rings such as Araldite PT810 manufactured by Ciba Specialty Chemicals, ERL4234, 4299, 4221, 4206 manufactured by UCC, etc. The alicyclic epoxy resin of these is mentioned, These can be used individually or in combination of 2 or more types. 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. The epoxy resin of component (B) used in the present invention 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. 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 methyl (3,4-epoxycyclohexane) carboxylate can be used.

The amount of the epoxy resin used as the component (B) in the present invention is preferably 1 to 50 parts by weight, more preferably 2 to 45 parts by weight, based on 100 parts by weight of the resin of the component (A) and the component (A ′).
More preferably, it is 3 to 40 parts by weight. When the compounding amount of the epoxy resin is less than 1 part by weight, the solvent resistance, chemical resistance and moisture resistance 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 dissolving in advance in the same solvent as the solvent contained in the resin, or may be added directly to the resin.
In the resin composition of the present invention, surfactants such as organic or inorganic fillers, antifoaming agents, and leveling agents are used as necessary to improve workability during coating and film properties before and after film formation. , Coloring agents such as dyes or pigments, curing accelerators, heat stabilizers, antioxidants, flame retardants, and lubricants can be added.

The resin composition of the present invention can be used for a solder resist layer for pre-tin plating in the field of flexible substrates.
The intended effect of the resin composition of the present invention can be obtained by using a resin obtained by using the diisocyanate as the component (b) described above, or by using an epoxy resin.

Hereinafter, the present invention will be described in detail with reference to examples.
[Example 1]
To a 5 liter four-necked flask equipped with a stirrer, a cooling pipe with an oil / water separator, a nitrogen introduction pipe and a thermometer, Kuraray polyol C-2015N (trade name of polycarbonate diol manufactured by Kuraray Co., Ltd., raw material diol molar ratio: 1,9 Nonanediol: 2-methyl-1,8-octanediol = 15: 85) 1000.0 g (0.50 mol) and T-80 (trade name of tolylene diisocyanate manufactured by Mitsui Takeda Chemical Co., Ltd., raw material diisocyanate molar ratio : 2,4-tolylene diisocyanate: 2,6-tolylene diisocyanate = 80:20)) 176.0 g (1.01 mol) and γ-butyrolactone 1000.0 g were charged, nitrogen was introduced, and the temperature reached 140 ° C. The temperature rose. Reaction at 140 ° C. for 5 hours, diisocyanate as component (b) [in general formula (III), assuming no molecular weight distribution, calculated from the charge ratio, 15% of R is nonamethylene group, 85% of 2-position Represents a methylated octamethylene group, 80% of X represents a 2,4-tolylene group, 20% represents a 2,6-tolylene group, and m = 10 and n = 1. Furthermore, 310.2 g (1.00 mol) of 3,3 ′, 4,4′-diphenyl ether tetracarboxylic dianhydride as component (a) was added to this reaction solution, and 8-80 g of T-80 as component (c) ( 0.50 mol) and 1230.0 g of γ-butyrolactone, heated to 160 ° C., reacted for 5 hours, and the repeating unit represented by the general formula (I) [in the general formula (I), the molecular weight Assuming that there is no distribution, 65% of R represents a nonamethylene group, 35% represents an octamethylene group methylated at the 2-position, 80% of X represents a 2,4-tolylene group, 20% Having a repeating unit in which% is a 2,6-tolylene group, m = 10, n = 1, and Y is a diphenyl ether-3,3 ′, 4,4′-tetrayl group], viscosity 300 Pa · s, number average Molecular weight of 14, 00, to obtain a nonvolatile content of 40% by weight of the polyimide resin solution. The molar ratio of component (b) / component (c) is 0.5 / 0.5. To 400 g of the obtained polyimide resin solution, 8.0 g of Aerosil R974 (trade name of silica fine particles manufactured by Nippon Aerosil Co., Ltd., primary particle average diameter 12 nm, surface area 170 m ^{2 /} g) is added, and further diluted with γ-butyrolactone. After the viscosity adjustment, rough kneading, and then kneading three times using a three-roll mill (manufactured by Kodaira Seisakusho Co., Ltd., RIII-1RM-2) to perform this mixing, a polyimide in which silica particles are uniformly dispersed A resin paste was obtained. Further, it was diluted with γ-butyrolactone to obtain a polyimide resin composition having a viscosity of 55 Pa · s and a nonvolatile content of 30% by weight.

[Example 2]
YH-434 (trade name of amine type epoxy resin manufactured by Toto Kasei Co., Ltd., epoxy equivalent of about 120, 4 epoxy groups / molecule) with respect to 100 parts by weight of the resin content of the polyimide resin solution obtained in Example 1 10 A part by weight was added and mixed to obtain a polyimide resin composition having a viscosity of 58 Pa · s and a nonvolatile content of 32% by weight.

Example 3
In Example 2, instead of 10 parts by weight of YH-434, Epicoat 828 (trade name of bisphenol A type epoxy resin manufactured by Yuka Shell Epoxy Co., Ltd., epoxy equivalent of about 189, 2 epoxy groups / molecule) 10 weights Except for using parts, the same operation as in Example 2 was performed to obtain a polyimide resin composition having a viscosity of 54 Pa · s and a nonvolatile content of 32% by weight.

[Comparative Example 1]
ETERRNACOLL UH-200 (trade name of 1,6-hexanediol-based polycarbonate diol manufactured by Ube Industries, Ltd.) in a 5-liter four-necked flask equipped with a stirrer, a condenser with an oil / water separator, a nitrogen inlet tube and a thermometer 1000.0 g (0.50 mol) and T-80 (trade name of tolylene diisocyanate manufactured by Mitsui Takeda Chemical Co., Ltd., raw material diisocyanate molar ratio: 2,4-tolylene diisocyanate: 2,6-tolylene diisocyanate = 80: 20)) 176.0 g (1.01 mol) and γ-butyrolactone 1000.0 g were charged, nitrogen was introduced, and the temperature was raised to 140 ° C. Diisocyanate as component (b) [in general formula (III), R represents all hexamethylene groups, 80% of X is 2,4-tolylene group, 20% is 2,6 -Diisocyanate showing a tolylene group and m = 13 and n = 1]. Furthermore, 310.2 g (1.00 mol) of 3,3 ′, 4,4′-diphenyl ether tetracarboxylic dianhydride as component (a) was added to this reaction solution, and 8-80 g of T-80 as component (c) ( 0.50 mol) and 1230.0 g of γ-butyrolactone, heated to 160 ° C., reacted for 5 hours, and the repeating unit represented by the general formula (I) [in the general formula (I), R All represent a hexamethylene group, 80% of X represents a 2,4-tolylene group, 20% represents a 2,6-tolylene group, m = 10, n = 1, Y represents diphenyl ether-3,3 ', 4 , 4′-tetrayl group repeating unit], a polyimide resin solution having a viscosity of 280 Pa · s, a number average molecular weight of 13,000 and a nonvolatile content of 40% by weight was obtained. The molar ratio of component (b) / component (c) is 0.5 / 0.5.

To 400 g of the obtained polyimide resin solution, 8.0 g of Aerosil R974 (trade name of silica fine particles manufactured by Nippon Aerosil Co., Ltd., primary particle average diameter 12 nm, surface area 170 m ^{2 /} g) is added, and further diluted with γ-butyrolactone. After the viscosity adjustment, rough kneading, and then kneading three times using a three-roll mill (manufactured by Kodaira Seisakusho Co., Ltd., RIII-1RM-2) to perform this mixing, a polyimide in which silica particles are uniformly dispersed A resin paste was obtained. Further, it was diluted with γ-butyrolactone to obtain a polyimide resin composition having a viscosity of 55 Pa · s and a nonvolatile content of 30% by weight.

[Comparative Example 2]
YH-434 (trade name of amine type epoxy resin manufactured by Toto Kasei Co., Ltd., epoxy equivalent of about 120, 4 epoxy groups / molecule) with respect to 100 parts by weight of the resin content of the polyimide resin solution obtained in Comparative Example 10 Part by weight was added and diluted with γ-butyrolactone to obtain a polyimide resin composition having a viscosity of 57 Pa · s and a nonvolatile content of 34% by weight.

[Comparative Example 3]
In Comparative Example 2, instead of 10 parts by weight of YH-434, Epicoat 828 (trade name of bisphenol A type epoxy resin manufactured by Yuka Shell Epoxy Co., Ltd., epoxy equivalent of about 189, 2 epoxy groups / molecule) 10 weights Except for the use of parts, the same operation as in Example 1 was performed to obtain a polyimide resin composition having a viscosity of 56 Pa · s and a nonvolatile content of 34% by weight.

  The physical properties of the polyimide resin compositions obtained in Examples 2 and 3 and Comparative Examples 2 and 3 were measured by the following methods, and the results are shown in Table 1.

(1) Warpage property The obtained polyimide resin composition was applied on a polyimide film having a thickness of 25 μm, dried at 80 ° C. for 30 minutes, then heated at 120 ° C. for 90 minutes in an air atmosphere, and then cooled once. The mixture was heated at 120 ° C. for 120 minutes and then at 150 ° C. for 30 minutes. This curing condition assumes a pre-tin plating process. The obtained coating film thickness was 10-15 μm. The film after thermosetting was cut into a circle with a diameter of 50 mm, placed with the printed surface facing upward, and evaluated according to the following criteria.
○: The maximum warp height is less than 5 mm. X: The maximum warp height is 5 mm or more.

(2) Solvent resistance The polyimide resin composition obtained on the rough surface of electroless tin plating (used plating solution TINPOSIT LT-34, manufactured by Rohm and Haas) formed on the rough surface of an electrolytic copper foil having a thickness of 12 μm. The product was applied and dried at 80 ° C. for 30 minutes, then heated at 120 ° C. for 90 minutes in an air atmosphere, then cooled once, and then heated at 120 ° C. for 120 minutes, and subsequently heated at 150 ° C. for 30 minutes. This curing condition assumes a pre-tin plating process. The obtained coating film thickness was 10-15 μm. The coating film was immersed in acetone at room temperature for 1 hour, and the change in coating film appearance was evaluated according to the following criteria.
○: No change in appearance △: Partial change in appearance ×: Change in overall appearance

(3) Electrical insulation (high temperature and high humidity bias test)
Create a comb pattern (line (μm) / space (μm) = 15/15) using Toyo Metallizing Co., Ltd. substrate (25 μm thick polyimide film, 8 μm thick copper foil). The polyimide resin composition thus obtained was applied and dried at 80 ° C. for 30 minutes, then heated at 120 ° C. for 90 minutes in an air atmosphere, then cooled once, and then heated at 120 ° C. for 120 minutes, and subsequently heated at 150 ° C. for 30 minutes. . This curing condition assumes pretin. The thickness of the obtained coating film was 10-15 μm. The substrate was left to stand for 1000 hours by applying a DC 60V bias voltage in an atmosphere of 85 ° C. and 85% relative humidity, and the electrical insulation was evaluated for the number of hours in which the insulation resistance was less than 10 6.

(4) Electrical insulation (accelerated test for high temperature and high humidity stress)
A thermosetting coating film was prepared in the same manner as the electrical insulation (high temperature and high humidity bias test) in (3) above, and a bias voltage of DC 60 V was applied to the substrate in an atmosphere of 120 ° C. and relative humidity of 85%. The electrical insulation was evaluated for the number of hours that the insulation resistance value (Ω) was less than 10 6.

  The solder resist resin composition for pre-tin plating of the present invention is soluble in a non-nitrogen-containing polar solvent and has low-temperature curability, and a cured product made thereof has low warpage, flexibility, adhesion to a sealing material, resistance to resistance. It is excellent in solvent resistance and chemical resistance, and is excellent in heat resistance, electrical properties, insulation reliability, and economic efficiency. Solder resists for pre-tin plating such as various electric parts and electronic parts obtained by forming a cured film using the resin composition of the present invention are excellent in reliability.

Claims (9)

(A) a resin having a repeating unit represented by the following general formula (I);

(In the above formula (I), a plurality of R's each independently represents an alkylene group having 8 to 9 carbon atoms which may be branched, and a plurality of X's each independently represents a group having 2 to 18 carbon atoms. An alkylene group or an arylene group, and m and n each independently represents an integer of 1 to 20, and Y represents a tetravalent organic group.) Resist resin composition.   The solder resist resin for pre-tin plating according to claim 1, wherein the number average molecular weight of the resin (A) having a repeating unit represented by the general formula (I) is in the range of 4,000 to 40,000. Composition.   The solder resist resin composition for pre-tin plating according to claim 1, wherein the plurality of R's are each independently a 1,9-nonylene group or a 2-methyl-1,8-octylene group.   The solder resist resin composition for pre-tin plating according to claim 3, wherein the plurality of Xs are each independently a tolylene group or a diphenylmethane-4,4′-yl group.   The solder resist resin composition for pre-tin plating according to any one of claims 1 to 4, wherein the organic solvent contains a non-nitrogen-containing polar solvent.   The solder resist resin composition for pre-tin plating according to claim 1, comprising 100 parts by weight of the component (A) resin and 1 to 50 parts by weight of the (B) epoxy resin. (A) a tetravalent polycarboxylic acid having an acid anhydride group,
(B) a diisocyanate represented by the general formula (II);

(In the formula, a plurality of R's each independently represents an alkylene group having 8 to 9 carbon atoms which may be independently branched, and a plurality of X's each independently represents an alkylene group or arylene group having 2 to 18 carbon atoms. M and n each independently represent an integer of 1 to 20) and (c) a resin having a repeating unit represented by the following general formula (I) reacted with a polyisocyanate compound:

(In the above formula (I), a plurality of R's each independently represents an alkylene group having 8 to 9 carbon atoms which may be branched, and a plurality of X's each independently represents a group having 2 to 18 carbon atoms. An alkylene group or an arylene group, m and n each independently represent an integer of 1 to 20, and Y represents a tetravalent organic group.
A method for producing a solder resist resin composition for tin plating, which comprises using   The blending ratio of the component (b) and the component (c) [(b) component / (c) component] is 0.1 / 0.9 to 0.9 in terms of the equivalent ratio of the component (b) and the component (c). And the ratio of the total number of acid anhydride groups in component (a) to the total number of isocyanate groups in components (b) and (c) is 0.6 to 1.4. The manufacturing method according to claim 7.   Solder resist hardened | cured material for the pre-tin plating formed by hardening | curing the resin composition in any one of Claims 1-6.