JPH0588905B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a resin composition for a laminate used for printed wiring boards, a prepreg using this resin composition, and a laminate obtained by curing this prepreg. [Prior Art] Epoxy resins have conventionally been widely used as resins for laminated boards and the like. Conventionally, methods for inspecting circuit patterns on printed wiring boards made from such laminates include a direct conduction method using a probe, a method using half-rays of metal conductor circuit patterns using a metallurgical microscope, and a method using soft X-rays. was. Recently, as a method for more accurate and highly efficient inspection, excitation light is used to develop fluorescence in the insulating layer of printed wiring boards, and conductor circuit patterns are used to conduct circuits by taking advantage of the property that they do not emit light especially in response to excitation light. Attempts are being made to put a fluorescent circuit pattern inspection method into practical use, which inspects patterns for abnormalities by comparing them with normal circuit patterns. However, a problem has arisen in that the same method cannot be used for inspection in cases where the circuit pattern of the laminate is thin or in the case of a multilayer laminate having a blackened inner layer printed wiring board. [Problems to be Solved by the Invention] The present invention, when processed into a printed wiring board,
It is an object of the present invention to provide a resin composition, a prepreg, and a laminate whose circuit patterns can be easily inspected using a fluorescent circuit pattern inspection method. [Means for Solving the Problems] The present invention has been made in view of the above points, and as a result of studying various substances that emit fluorescent light, the inventors have found that the physical properties of conventional laminates They discovered a coumarin derivative that exhibits remarkable fluorescence in response to excitation light even after being cured to form a laminate without damaging its properties, and completed the following three inventions. That is, the first invention provides: (a) an epoxy resin; (b) 0.03 to 100 parts by weight of the epoxy resin;
A resin composition for a laminate comprising a coumarin derivative blended in an amount within the range of 3 parts by weight, (iii) a curing agent, a curing accelerator, a solvent, and the like. The second invention provides: (a) an epoxy resin; (b) 0.03 to 100 parts by weight of the epoxy resin;
A coumarin derivative blended in an amount within the range of 3 parts by weight; (iii) A resin composition for a laminate comprising a curing agent, a curing accelerator, a solvent, etc., is impregnated into a base material and semi-cured. prepreg. The third invention provides: (a) an epoxy resin; (b) 0.03 to 100 parts by weight of the epoxy resin;
A coumarin derivative blended in an amount within the range of 3 parts by weight; This is a laminate plate characterized by being cured. These inventions will be explained in detail below. The resin composition according to the first invention consists of the following. Ingredients (a)
Examples of the epoxy resins include bisphenol A-type epoxy resins and halogenated bisphenol A-type epoxy resins that have been imparted with flame retardancy, or novolak-type epoxy resins that are used in combination to improve heat resistance, and Examples include halogenated novolac type epoxy resins that have flame retardancy. (B) As the coumarin derivative of the component, 7-hydroxycoumarin, 4-methyl-7-hydroxycoumarin, esculin (6,7-dihydrocoumarin-6
-glucoside), etc. can be used alone or in combination. The amount used is 0.03 parts by weight of the coumarin derivative per 100 parts by weight of the epoxy resin.
It is blended in an amount ranging from ~3 parts by weight. If the amount is less than 0.03 parts by weight, the fluorescence to excitation light will be weak, and if it is more than 3.0 parts by weight, the fluorescence to excitation light will be saturated, which is not economical, and the laminated board will not have good heat resistance or flame retardancy. This is not preferable because it deteriorates basic properties such as. The quantum yield of the coumarin derivative is preferably 0.3 or more. because,
Quantum yield is a physical property value that indicates the fluorescence of a substance, and in order to obtain large curing with a small amount of compounding, it is best to have a value as close to 1 as possible, and if it is less than 0.3, a large amount must be added due to the relationship between the amount of compounding and fluorescence intensity. Not necessarily,
This is not preferable because it is not economical and also reduces the basic properties of a laminate, such as open heat resistance and flame retardance. As the curing agent of component (c), dicyandiamide,
Commonly used compounds such as diaminodiphenylmethane can be used as appropriate, and the blending ratio thereof can be 1 to 20 parts by weight per 100 parts by weight of the epoxy resin. As a curing accelerator, 2
Commonly used compounds such as imidazoles such as ethyl 4-methylimidazole (2E4MZ) and tertiary amines such as benzyldimethylamine can be used as appropriate, and the blending ratio is 0.05 parts by weight per 100 parts by weight of the epoxy resin. ~1 part by weight can be used. As a solvent, dimethylformamide (DMF), methyl ethyl ketone (MEK), acetone, methyl cellosolve, dimethyl acetamide, dioxane, etc., alone or in combination, are used at a resin content of 40 to 80% by weight, preferably 55 to 70% by weight. It can be used in amounts. The prepreg according to the second invention is obtained by impregnating a base material with the resin composition according to the first invention, and then proceeding with the reaction of the epoxy resin while evaporating the solvent by drying. Obtained by semi-curing. The type of substrate impregnated with the resin composition according to the first invention is not particularly limited. Usually, glass cloth or the like is used. In addition, inorganic fiber cloth such as quartz fiber cloth, highly heat-resistant organic fiber cloth such as polyimide resin fiber cloth, etc. may be used. The temperature during semi-curing is preferably 140 to 170°C.
If the temperature exceeds 170℃, the reaction of the epoxy resin will proceed too much.
The interlayer adhesion strength of the resulting prepreg decreases. The laminate according to the third invention is made using the prepreg according to the second invention. That is,
If necessary, it is made by laminating prepreg together with a metal foil such as copper, nickel, or aluminum, or a metal foil with a circuit formed thereon. Lamination molding can be performed by a conventional method. Note that this laminate was made from the prepreg of the second invention, in which the resin composition containing the coumarin derivative according to the first invention was used, so this laminate was made from the prepreg. From 350
This makes it possible to obtain a laminate that exhibits significant fluorescence against excitation light of 500 nm. Next, the first to third inventions will be explained using examples and comparative examples. [Example] Example 1 (a) Brominated epoxy resin (Toto Kasei Co., Ltd., YDB-500, epoxy equivalent: 500) was used as the epoxy resin.
100 parts by weight, (b) 0.03 parts by weight of 7-hydroxycoumarin with a quantum yield of 0.37 as a coumarin derivative,
(c) Prepare a resin composition consisting of 2 parts by weight of dicyandiamide as a curing agent, 0.1 parts by weight of 2E4MZ as a curing accelerator, 27 parts by weight of methyl ethyl ketone and 27 parts by weight of dimethyl formamide as a solvent, and A prepreg was obtained by impregnating a glass cloth with a thickness of 0.1 mm with the composition and drying it for 15 minutes in a dryer at 150°C. A double-sided roughened copper foil of 18 μm was placed on both sides of this prepreg, and a steam press was used at a molding temperature of 170°C and a molding pressure of 50 kg/kg.
Laminate molding was carried out under the conditions of cm ² and 100 minutes to obtain a double-sided copper-clad laminate for an inner layer printed wiring board with a thickness of 0.1 mm.
An inner layer printed wiring board was prepared by etching the copper foil of the double-sided copper-clad laminate thus obtained to form a circuit. This wiring board was irradiated with excitation light of 350 to 500 nm using a spectrofluorometer, and the maximum value of the fluorescence intensity that appeared at that time was shown in Table 1 as the fluorescence intensity. In addition, we applied a fluorescent pattern inspection device using 442nm excitation light to this 300mm x 500mm wiring board and inspected the circuit pattern for conductor width, conductor spacing, disconnections, shorts, pinholes, copper residue, and copper chips. The circuit patterns that were detected as abnormal by the fluorescent pattern inspection device are observed again using a microscope, and the number of circuit patterns that are confirmed to be normal, i.e., the number of circuit patterns detected incorrectly by the fluorescent pattern inspection device, is inspected. The accuracy results are also shown in Table 1. Example 2 The same procedure as in Example 1 was carried out except that the amount of 7-hydroxycoumarin in Example 1 was changed to 1 part by weight, and the results shown in Table 1 were obtained. Example 3 The same procedure as in Example 1 was carried out except that the amount of 7-hydroxycoumarin in Example 1 was changed to 3 parts by weight, and the results shown in Table 1 were obtained. Example 4 The same procedure as in Example 2 was performed except that the coumarin derivative in Example 2 was changed to 4-methyl-7-hydroxycoumarin with a quantum yield of 0.41, and the results shown in Table 1 were obtained. Example 5 The same procedure as in Example 2 was carried out except that the coumarin derivative in Example 2 was changed to esculin having a quantum yield of 0.64, and the results shown in Table 1 were obtained. Comparative Example 1 The same procedure as Example 2 was used except that a resin composition was used that did not contain the coumarin derivative of Example 2.
Obtained the results in the table. Example 6 An insulating substrate on which the prepreg in Example 2 was cured and a circuit pattern formed on this insulating substrate were blackened and coated with 18 μm thick sheets of prepreg of Example 2 on the top and bottom of the insulating substrate. layered with copper foil and pressed at a pressure of 50Kg/ ^cm2 using a steam press.
It was heated to 170°C, held for 100 minutes, and then cooled to room temperature while applying pressure to obtain a double-sided copper-clad multilayer laminate. A circuit pattern was formed on this laminate to create a multilayer printed wiring board. This wiring board was irradiated with excitation light of 350 to 500 nm using a spectrofluorometer, and the maximum value of the fluorescence intensity that appeared at that time was shown in Table 1 as the fluorescence intensity. In addition, we applied a fluorescent pattern inspection device using 442nm excitation light to this 300mm x 500mm wiring board and inspected the circuit pattern for conductor width, conductor spacing, disconnections, shorts, pinholes, copper residue, and copper chips. The circuit patterns that were detected as abnormal by the fluorescent pattern inspection device are observed again using a microscope, and the number of circuit patterns that are confirmed to be normal, i.e., the number of circuit patterns detected incorrectly by the fluorescent pattern inspection device, is inspected. The accuracy results are also shown in Table 2. Example 7 The same procedure as in Example 6 was carried out except that the inner layer printed wiring board and prepreg of Example 2 used in Example 6 were changed to the inner layer printed wiring board and prepreg of Example 4, and the results are shown in Table 2. I got it. Example 8 The same procedure as in Example 6 was carried out except that the inner layer printed wiring board and prepreg of Example 2 used in Example 6 were changed to the inner layer printed wiring board and prepreg of Example 5, and the results are shown in Table 2. I got it. Comparative Example 2 The same procedure as in Example 6 was carried out except that the inner layer printed wiring board and prepreg of Example 2 used in Example 6 were changed to the inner layer printed wiring board and prepreg of Comparative Example 1, and the results in Table 2 were obtained. Obtained.

【table】

〔Effect of the invention〕

Since the resin composition according to the first invention, the prepreg according to the second invention, and the laminate according to the third invention are configured as described above, if they are used, it is possible to obtain fluorescence by excitation light. Resin compositions, prepregs, and laminates that emit light and provide printed wiring boards that can be easily inspected using a fluorescent circuit pattern inspection machine can be obtained.

Claims (1)

[Claims] 1. (a) Epoxy resin; (b) 0.03 to 100 parts by weight of the epoxy resin;
A resin composition for a laminate comprising a coumarin derivative blended in an amount within the range of 3 parts by weight, (iii) a curing agent, a curing accelerator, a solvent, and the like. 2. The resin composition for a laminate according to claim 1, wherein the coumarin derivative has a quantum yield of 0.3 or more. 3. The resin for a laminate according to claim 1 or 2, wherein the coumarin derivative is one or a combination of 7-hydroxycoumarin, 4-methyl-7-hydroxycoumarin, and aesculin. Composition. 4 (a) Epoxy resin, (b) 0.03 to 100 parts by weight of the epoxy resin
A coumarin derivative blended in an amount within the range of 3 parts by weight; Features of prepreg. 5. The prepreg according to claim 4, wherein the coumarin derivative has a quantum yield of 0.3 or more. 6. The prepreg according to claim 4 or 5, wherein the coumarin derivative is one or a combination of 7-hydroxycoumarin, 4-methyl-7-hydroxycoumarin, and aesculin. 7 (a) Epoxy resin, (b) 0.03 to 100 parts by weight of the above epoxy resin
A coumarin derivative blended in an amount in the range of 3 parts by weight. (c) And a laminate, characterized in that it is a semi-cured prepreg obtained by impregnating a base material with a resin composition for a laminate consisting of a curing agent, a curing accelerator, a solvent, etc. and semi-curing it. 8. The laminate according to claim 7, wherein the coumarin derivative has a quantum yield of 0.3 or more. 9. The laminate according to claim 7 or 8, wherein the coumarin derivative is one or a combination of 7-hydroxycoumarin, 4-methyl-7-hydroxycoumarin, and aesculin.