JP2012043833A - Light-blocking coverlay film and resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly practical light-blocking coverlay film having an excellent adhesive strength and fire resistance in addition to sufficient light-blocking property and high electric reliability.SOLUTION: The light-blocking coverlay film comprises: a base material; and a light-blocking resin composition coated on the base material. The resin composition includes thermosetting resin to which a nonconductive red pigment, a nonconductive blue pigment and a nonconductive yellow pigment are added. The red pigment is added at 20-60 wt% with respect to total weight of all the pigments, the blue pigment is added at 5-40 wt% with respect to the total weight of all the pigments and the yellow pigment is added at 20-60 wt% with respect to the total weight of all the pigments. Parts by the total weight of the red pigment, the blue pigment and the yellow pigment is set at 1-20 wt% with respect to a weight of the resin composition.

Description

  The present invention relates to a light-shielding coverlay film and a resin composition.

  In recent years, the use of flexible printed wiring boards has expanded, and in particular, they are increasingly used in optical systems such as cameras and laser disks. In this case, the reflected light or transmitted light on the surface of the flexible printed wiring board may interfere with these functions. Therefore, in order to block reflected light and transmitted light, the coverlay film is required to have a light shielding property.

  In addition, since a conventional coverlay film uses a transparent or translucent film such as a polyimide film, a circuit such as a metal-clad laminate for a flexible printed wiring board is visible from the appearance. As a result, there has been a problem that the arrangement of the circuit can be imitated relatively easily. In order to solve this problem, imitation may be prevented by coloring the coverlay film with black or the like to impart light shielding properties and concealing the circuit.

  Examples of such a coverlay film having a light shielding property are disclosed in Patent Documents 1 and 2.

  In Patent Document 1, the polyimide substrate is colored black with a dye or pigment. In Patent Document 2, the resin composition or polyimide substrate is colored black with carbon black, acetylene black, or a metal oxide material. Thus, the coverlay film is provided with a light shielding property.

  Here, the coverlay film is a film in which a resin composition is laminated as an adhesive on a film of polyimide, polyethylene terephthalate, polyamide, polycarbonate, etc., and is a metal-clad laminate for a flexible printed wiring board provided with a circuit. Used as provided to protect the circuit.

JP-A-6-350210 Japanese Patent Laid-Open No. 9-135067

  However, in the method disclosed in Patent Document 1, since the color is lost when the polyimide base material is formed, sufficient light shielding properties cannot be obtained. That is, the polyimide base material is formed by casting the stock solution on a belt and immersing it in an aqueous solution of black pigment, curing the stock solution soaked with the black pigment by heat treatment at about 400 ° C. to 500 ° C. and winding it. However, the heat-resistant temperature of the black pigment component is about 300 ° C., and it cannot withstand the heat treatment and is decomposed.

  Further, in the method disclosed in Patent Document 2, since carbon black and acetylene black are highly conductive substances, the electrical reliability required for the coverlay film is reduced. Note that the metal oxide material is non-conductive, but unreacted metal is present during the oxidation reaction, which similarly reduces the electrical reliability.

  In the present invention, as a result of intensive studies by the present inventors in order to solve the above problems, the resin composition is sufficiently obtained by adding a predetermined amount of each non-conductive primary color pigment to the thermosetting resin. It was found that the pigment has excellent light-shielding properties and electrical reliability, and that the pigment has flame retardancy. It can obtain sufficient light-shielding properties, and of course has high electrical reliability and good adhesion. The present invention provides a light-shielding coverlay film and a resin composition excellent in practicality having strength and flame retardancy.

  The gist of the present invention will be described with reference to the accompanying drawings.

  A light-shielding coverlay film formed by applying a light-shielding resin composition to a substrate, wherein the resin composition is obtained by adding a non-conductive red pigment, blue pigment, and yellow pigment to a thermosetting resin. The red pigment is added in an amount of 20 to 60 wt% with respect to the total weight part of each pigment, the blue pigment is added in an amount of 5 to 40 wt% with respect to the total weight part of each pigment, and the yellow pigment is 20 to 60 wt% is added to the total weight part of each pigment, and the total weight part of the red pigment, the blue pigment and the yellow pigment is 1 to 20 wt% with respect to the weight part of the resin composition. The present invention relates to a light-shielding coverlay film characterized by being set.

  The light-shielding coverlay film according to claim 1, wherein the resin composition is added with 30 to 200 parts by weight of an inorganic filler with respect to 100 parts by weight of the thermosetting resin. The cover lay film is concerned.

  Further, in the light-shielding coverlay film according to any one of claims 1 and 2, in the resin composition, a curing agent is an amine group or a phenol group in the curing agent with respect to an epoxy group in the thermosetting resin. The present invention relates to a light-shielding coverlay film which is added so that the molar ratio of hydroxyl groups is 0.1 to 1.0.

  Further, in the light-shielding coverlay film according to claim 3, 0.01 to 3.0 parts by weight of a curing catalyst is added to 100 parts by weight of the curable resin in the resin composition. The present invention relates to a light-shielding coverlay film.

  Moreover, the light-shielding coverlay film of any one of Claims 3 and 4 WHEREIN: The polymer component is added to the resin composition by 30 to 120 parts by weight with respect to 100 parts by weight of the thermosetting resin. The present invention relates to a light-shielding cover lay film.

  The resin composition is obtained by adding a non-conductive red pigment, blue pigment, and yellow pigment to a thermosetting resin, and the red pigment is added in an amount of 20 to 60 wt% with respect to the total weight part of each pigment. The blue pigment is added in an amount of 5 to 40 wt% with respect to the total weight part of the pigments, and the yellow pigment is added in an amount of 20 to 60 wt% with respect to the total weight parts of the pigments. The total weight part of the blue pigment and the yellow pigment is set to 1 to 20 wt% with respect to the weight part of the resin composition.

  Since the present invention is configured as described above, it is possible to obtain a sufficient light-shielding property, high electrical reliability, as well as a light-shielding cover layer excellent in practicality having good adhesion and flame retardancy. It becomes a film and a resin composition.

It is a table | surface which shows the compounding example of a comparative example and an Example. It is a table | surface which shows the content etc. of each component of the resin composition of FIG.

  An embodiment of the present invention which is considered to be suitable will be briefly described with reference to the drawings showing the operation of the present invention.

  Because a predetermined amount of each non-conductive primary color pigment is added to the thermosetting resin to provide light shielding properties, for example, when forming a polyimide film as a base material, the color does not fall off, and the electrical reliability is also high. It will be a thing.

  In addition, since each primary color pigment has flame retardancy, for example, the amount of inorganic filler added as a flame retardant can be reduced, and the adhesive strength of the inorganic filler can be reduced while ensuring flame retardancy. It is possible to suppress the adhesive strength and flame retardancy at a practical level.

  Specific embodiments of the present invention will be described with reference to the drawings.

  This example is a light-shielding coverlay film obtained by applying a light-shielding resin composition to a base material, and the resin composition comprises a thermosetting resin and a non-conductive red pigment, blue pigment, and A yellow pigment is added in a predetermined amount. “Parts by weight” and “total parts by weight” described below indicate “weight in terms of solid content”.

  Specifically, an epoxy resin is employed as the thermosetting resin. In addition to the pigment, a predetermined amount of an inorganic filler, a curing agent, a curing catalyst, and a polymer component (elastomer system or the like) are added to the thermosetting resin.

  Here, in order to obtain sufficient light-shielding properties and flame retardancy, the amount of the pigment added is preferably set to about 1 to 20 wt% with respect to parts by weight of the resin composition. If it is less than 1 wt%, coloring is insufficient and sufficient light-shielding properties and flame retardancy cannot be obtained, and if it exceeds 20 wt%, the adhesive strength is reduced. In addition, it is more preferable to set to 3-10 wt%.

  Further, the mixing ratio of each primary color pigment is preferably set to 20 to 60 wt% of a red pigment, 5 to 40 wt% of a blue pigment, and 20 to 60 wt% of a yellow pigment with respect to the total weight part of each pigment. With such a mixing ratio, a color close to black can be expressed sufficiently. In addition, it is more preferable to set it to 30-50 wt% of red pigments, 10-30 wt% of blue pigments, and 30-50 wt% of yellow pigments.

  Moreover, in order to improve the properties such as flame retardancy and linear expansion coefficient of the cured product, the addition amount of the inorganic filler is preferably 30 to 200 parts by weight with respect to 100 parts by weight of the thermosetting resin, More preferred is 50 to 150 parts by weight.

  The addition amount of the curing agent is preferably such that the molar ratio of the amine group or phenolic hydroxyl group in the curing agent is 0.1 to 1.0 with respect to the epoxy group in the thermosetting resin. It is more preferable that it is 2-0.6.

  Moreover, in order to improve the properties such as adhesive strength, chemical resistance, and heat resistance of the cured product, the addition amount of the curing catalyst is 0.01 to 3.0 parts by weight with respect to 100 parts by weight of the thermosetting resin. It is preferably 0.1 to 1.0 part by weight.

  Moreover, in order to improve the mechanical strength characteristics such as the adhesive strength of the cured product, the addition amount of the polymer component is preferably 30 to 120 parts by weight with respect to 100 parts by weight of the thermosetting resin. More preferably, it is -90 weight part.

  As each compounding component, the following can be adopted, for example. The pigment preferably has a structure having a highly flame-retardant component such as an aromatic, an amide bond, or a nitrogen atom. Specifically, it is as follows.

Examples of red pigments include monoazo, disazo, azo lake, benzimidazolone, perylene, diketopyrrolopyrrole, condensed azo, anthraquinone, and quinacridone. Those with color index numbers can be used.
・ Monoazo: Pigment Red 1,2,3,4,5,6,8,9,12,14,15,16,17,21,22,23,31,32,112,
114,146,147,151,170,184,187,188,193,210,245,253,258,
266,267,268,269
・ Disazo: Pigment Red 37,38,41
・ Mono azo lake system: Pigment Red 48: 1,48: 2,48: 3,48: 4,49: 1,49: 2,50: 1,52: 1,52: 2,
64: 1,68
・ Benz imidazolone series: Pigment Red 171,175,176,185,208
・ Perylene: Solvent Red 135,179, Pigment Red 123,149,166,178,179,190,194,224
・ Diketopyrrolopyrrole: Pigment Red 254,255,264,270,272
・ Condensed azo: Pigment Red 144,166,214,220,221,242
・ Anthraquinone series: Pigment Red 168,216, Solvent Red 149,150,152,207
・ Quinacridone series: Pigment Red 122,202,206,207,209

Blue pigments include phthalocyanine-based, anthraquinone-based, dioxazine-based pigments, and specifically, pigments with the following color index numbers can be employed.
・ Pigment Blue 15,15: 1,15: 2,15: 3,15: 4,15: 6,60
・ Solvent Blue 35,63,67,68,70,83,87,94,97,122,136

  In addition, metal-substituted or inorganic-substituted phthalocyanine compounds can also be employed.

Examples of yellow pigments include monoazo, disazo, condensed azo, benzimidazolone, isoindolinone, and anthraquinone, and specifically, those with the following color index numbers it can.
-Monoazo: Pigment Yellow 1,2,3,4,5,6,9,10,12,61,62,62: 1,65,73,74,75,97,
100,104,105,111,116,167,168,169,182,183
・ Disazo series: Pigment Yellow 12,13,14,16,17,55,63,81,83,87,126,127,152,170,
172,176,188,198
・ Condensed azo: Pigment Yellow 93,94,95,128,155,166,180
・ Benz imidazolone series: Pigment Yellow 120,151,154,156,175,181
・ Isoindolinone: Pigment Yellow 109,110,139,179,185
・ Anthraquinone series: Solvent Yellow 24,108,147,163,193,199,202

  Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, naphthalene type epoxy resin, glycidylamine type epoxy resin, cresol novolac type epoxy resin, biphenyl type epoxy resin, linear fat A group epoxy resin, an alicyclic epoxy resin, a heterocyclic epoxy resin, and the like can be employed. Two or more types of epoxy resins may be used in combination. In this case, an epoxy resin having two or more epoxy groups in one molecule is usually contained.

  Examples of the inorganic filler that can be used include barium sulfate, barium titanate, silicon oxide, silica, talc, clay, magnesium carbonate, aluminum oxide, and aluminum hydroxide.

  As a hardening | curing agent, it can select widely from what is used as a hardening | curing agent of epoxy resins, such as an amine type and a phenol type. As the amine curing agent, diethylenetriamine, triethylenetetramine, metaxylylenediamine, isophoronediamine, 1,3-bisaminomethylcyclohexane, diaminodiphenylmethane, metaphenylenediamine, diaminodiphenylsulfone, dicyandiamide, etc. can be adopted, and phenolic curing As the agent, phenol novolak resin, cresol novolak resin, naphthol modified phenol resin, dicyclopentadiene modified phenol resin, dicyclopentadiene modified phenol resin, p-xylene modified phenol resin and the like can be employed.

  As the curing catalyst, imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1- (2-cyanoethyl) -2-ethyl-4- Methylimidazole derivatives, amine compounds such as dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, and 4-methyl-N, N-dimethylbenzylamine can be employed.

  As the polymer component, 1,2-polybutadiene elastomer, isopropylene elastomer, butadiene elastomer, styrene butadiene elastomer, nitrile elastomer, urethane elastomer, ethylene-propylene elastomer, acrylic elastomer, silicon elastomer, and the like can be used.

  Moreover, in the range which does not reduce various characteristics, you may add various additives, for example, surfactant, a coupling agent, etc. to the said resin composition as needed in addition to each component mentioned above. In the cover lay film of this embodiment, it is preferable that the thickness of the substrate is 5 μm to 100 μm and the thickness of the layer made of the resin composition is 5 μm to 50 μm. In addition, the thickness of the layer which consists of a resin composition shows the thickness after drying the resin composition of a coverlay film at predetermined | prescribed temperature.

  As the base material, for example, a polyimide film, a polyester film, a polyamide film or the like is adopted, and among them, a polyimide film is preferable in terms of flame retardancy, electrical insulation, heat resistance, elastic modulus and the like. In addition, you may employ | adopt the film of another raw material.

  In the present example, the materials shown in FIG. 1 are employed, and these are blended at the blending ratio in the column of the example. Comparative Examples 1 to 7 in FIG. 1 employ the same materials as in the examples (pigments are not blended in Comparative Examples 1 and 2), and the blending ratio is varied for each example. And the effect of an Example was confirmed by evaluating these light-shielding properties, adhesive force, and a flame retardance. However, the present invention is not limited to the examples.

  The coverlay film in this example was produced by the following method.

  The resin compositions of the above comparative examples and examples were applied to a polyimide film [Apical 12.5 NPI manufactured by Kaneka Corporation] using a bar coder so that the thickness after drying was 25 μm. Let dry for minutes.

  The following evaluation test was performed on the coverlay film (semi-cured state) obtained by the above method.

<Light shielding>
The light shielding property was evaluated by measuring the light transmittance (%) at a wavelength of 500 nm using a spectrophotometer [U-4100 manufactured by Hitachi, Ltd.].

As a sample used for this evaluation, the coverlay film obtained by the above method was dried at 160 ° C. for 3 hours and used in a completely cured state. Evaluation was performed as follows.
A: The light transmittance is less than 1%, and the light-shielding property has no practical problem at all.
A: The light transmittance is 1% or more and less than 15%, and has a practical light shielding property.
(Triangle | delta): Light transmittance is 15% or more and less than 25%, and light-shielding property is a little inadequate.
X: The light transmittance is 25% or more, and the light shielding property is insufficient.

<Adhesive strength>
The adhesive strength was evaluated by measuring the peel strength using an autograph manufactured by Shimadzu Corporation. The evaluation method was performed in accordance with IPC TM650 (90 ° film drawing).

The sample used for this evaluation was made by laminating a coverlay film on a glossy surface of copper foil [JTC-1.0 oz (35 μm) manufactured by JX Nippon Mining & Metals Co., Ltd.], 160 ° C., 2.94 MPa (per 1 cm ² . Pressure), and heated and pressurized under 60 minutes. Evaluation was performed as follows.
(Double-circle): The peeling force is 6.5 N / cm or more, and it has the adhesive force which has no practical problem at all.
○: Peeling force is 5.5 N / cm or more and less than 6.5 N / cm, and has a practical adhesive force.
Δ: The peeling force is 4.5 N / cm or more and less than 5.5 N / cm, and the adhesive force is slightly insufficient.
X: The peeling force is less than 4.5 N / cm, and the adhesive force is insufficient.

<Flame retardance>
The evaluation of flame retardancy was performed based on whether or not the V-0 grade could be achieved according to the UL94 standard.

The sample used for this evaluation is a polyimide film [Apical 12.5 NPI manufactured by Kaneka Corporation] laminated with a coverlay film, and heated and pressurized at 160 ° C., 2.94 MPa (pressure per 1 cm ² ) for 60 minutes. What was done was used. Evaluation was performed as follows.
A: UL94 standard V-0 grade can be achieved.
○: UL94 standard V-0 grade can be achieved, but slightly inferior to ◎. There is no problem in practical use.
(Triangle | delta): UL94 specification V-0 grade may not be achieved, but there is a problem in practical use.
X: UL94 standard V-0 grade cannot be achieved.

  The above evaluation results are also shown in FIG.

  Comparative Example 1 is an example that does not contain a pigment. Therefore, naturally, the light shielding property is insufficient.

  Comparative Example 2 is obtained by reducing the amount of inorganic filler added as compared with Comparative Example 1. The adhesive strength is improved as compared with Comparative Example 1, but the flame retardancy is reduced, and it is the same as Comparative Example 1. However, the light shielding property is insufficient.

  In Comparative Example 3, a slight amount of pigment is added to Comparative Example 1, but the light shielding property is not sufficient.

  In Comparative Example 4, the amount of pigment added was increased from that in Comparative Example 3, and the light shielding property was improved as compared with Comparative Example 3, but the adhesive strength was reduced.

  In Comparative Example 5, the amount of the pigment added was increased compared to Comparative Example 4, and the flame retardancy was improved and very good as compared with Comparative Example 4, and the light-shielding property was also improved, but it was not sufficient.

  In Comparative Example 6, the amount of the pigment added is increased from that in Comparative Example 5. The light shielding property is improved and the flame retardancy is very good as compared with Comparative Example 5, but the adhesive strength is reduced.

  Comparative Example 7 is obtained by reducing the amount of the inorganic filler as compared with Comparative Example 6. Although the adhesive force is slightly improved as compared with Comparative Example 6, the flame retardancy is reduced.

  In the examples, the amount of the inorganic filler is further reduced as compared with Comparative Example 7, and it can be confirmed that the light shielding property is very good, and the adhesive strength and the flame retardancy are compatible.

  Since this embodiment is configured as described above, a predetermined amount of each non-conductive primary pigment is added to the thermosetting resin to provide light shielding properties. For example, when forming a polyimide film as a substrate, Does not fall out, and the electrical reliability is high.

  In addition, by adding a predetermined amount of a pigment having a structure that exhibits flame retardancy, such as an aromatic, amide bond, or nitrogen atom, the flame retardancy is manifested in the resin composition or the coverlay film itself. . Thereby, even if it reduces the addition amount of the inorganic filler which was added as a flame retardant, sufficient flame retardance can be ensured. Furthermore, since the amount of inorganic filler added as a flame retardant can be reduced, it is possible to suppress a decrease in adhesive strength due to the inorganic filler while ensuring flame retardancy, and to achieve a practical level of adhesive strength and flame retardancy. It is possible to achieve both.

  Therefore, this example can obtain a sufficient light-shielding property and is excellent in practicality having good adhesive force and flame retardancy as well as high electrical reliability.

Claims (6)

  A light-shielding coverlay film formed by applying a light-shielding resin composition to a substrate, wherein the resin composition is obtained by adding a non-conductive red pigment, blue pigment, and yellow pigment to a thermosetting resin. The red pigment is added in an amount of 20 to 60 wt% with respect to the total weight part of each pigment, the blue pigment is added in an amount of 5 to 40 wt% with respect to the total weight part of each pigment, and the yellow pigment is 20 to 60 wt% is added to the total weight part of each pigment, and the total weight part of the red pigment, the blue pigment and the yellow pigment is 1 to 20 wt% with respect to the weight part of the resin composition. A light-shielding coverlay film that is set.   2. The light-shielding coverlay film according to claim 1, wherein an inorganic filler is added to the resin composition in an amount of 30 to 200 parts by weight with respect to 100 parts by weight of the thermosetting resin. the film.   The light-shielding coverlay film according to any one of claims 1 and 2, wherein in the resin composition, the curing agent has an amine group or a phenolic hydroxyl group in the curing agent with respect to an epoxy group in the thermosetting resin. A light-shielding coverlay film, which is added so as to have a molar ratio of 0.1 to 1.0.   The light-shielding coverlay film according to claim 3, wherein a curing catalyst is added to the resin composition in an amount of 0.01 to 3.0 parts by weight with respect to 100 parts by weight of the curable resin. Coverlay film.   5. The light-shielding coverlay film according to claim 3, wherein a polymer component is added to the resin composition in an amount of 30 to 120 parts by weight with respect to 100 parts by weight of the thermosetting resin. Features a light-shielding coverlay film.   A resin composition obtained by adding a non-conductive red pigment, a blue pigment, and a yellow pigment to a thermosetting resin, wherein the red pigment is added in an amount of 20 to 60 wt% with respect to the total weight part of each pigment, The blue pigment is added in an amount of 5 to 40 wt% with respect to the total weight part of the pigments, and the yellow pigment is added in an amount of 20 to 60 wt% with respect to the total weight parts of the pigments. The total weight part of a pigment and the said yellow pigment is set to 1-20 wt% with respect to the weight part of the said resin composition, The resin composition characterized by the above-mentioned.

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