JP2013173368A - Laminated material for electric insulation, and printed wiring board using the laminated material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated material for electric insulation with an optional specific inductive capacity by combining insulating materials with different specific inductive capacities and by a specific combining method and a printed wiring board using the laminated material.SOLUTION: A laminated material comprising conductor layers on the upper side and the lower side of insulating layers is characterized in that the insulating layers are constituted of two or more of insulating layers different in specific inductive capacities and contacting with the conductor layers, and the insulating layers not contacting with the conductor layers are different in the specific inductive capacities.

Description

  The present invention relates to a laminated material for electrical insulation and a printed wiring board using the laminated material.

  With the recent diversification of electrical and electronic equipment and diversified technical issues, the required specifications have changed greatly in the field of electrical and electronic materials, and inorganic materials such as ceramics have been used. Organic materials have been adopted in various fields, and laminated materials for electrical insulation have been developed in a wide variety of fields.

  Accordingly, demands for laminated materials for electrical insulation have been diversified in various ways such as mechanical characteristics, electrical characteristics, physical characteristics, and chemical characteristics. Among the electrical characteristics, there are various requirements regarding dielectric characteristics (relative dielectric constant, dielectric loss tangent, etc.), and there is a demand for providing laminated materials for electrical insulation having various dielectric constants.

  Among them, a laminate material for electrical insulation having special dielectric properties is very expensive compared to a typical laminate material for electrical insulation, but is required to be provided at a lower cost.

  Patent Documents 1 to 7 disclose that the relative dielectric constant is adjusted using two or more materials having different dielectric constants. For example, Patent Document 1 attempts to adjust the relative dielectric constant by using a prepreg to which titanium oxide is added as a part of the prepreg to be used.

  Of the prepregs used in this technique, when a resin for a general laminated material for electrical insulation is used as a base when adding titanium oxide, the resin can be obtained at a relatively low cost. Also, a prepreg to which titanium oxide is not added among prepregs to be used can use a general electrical insulation laminate material, and therefore there is a possibility that the electrical insulation laminate material can be produced at a relatively low cost.

  However, the above Patent Documents 1 to 7 do not specify the material arrangement. Depending on the arrangement of materials, the relative permittivity of the printed wiring board may vary greatly.

  Therefore, even if the produced laminated material for electrical insulation uses the same prepreg, the same effect may not be obtained depending on the configuration of the prepreg.

Japanese Patent No. 2998542 JP 2000-238162 A JP 2000-313818 A JP2001-181460 JP 2001-347600 A JP 05-057852 A JP 05-0633323

  The present invention provides an insulating material having an arbitrary relative dielectric constant and a printed wiring board using the laminated material by combining insulating materials having different relative dielectric constants and performing a specific combination. It is intended.

  Therefore, by laminating at least two types of existing base materials with different relative dielectric constants and adopting a structure in which the dielectric constant is positively controlled by the material in contact with the conductor, a laminated material for electrical insulation having an arbitrary relative dielectric constant is completed. It came to do.

  That is, the present invention is a laminated material having conductor layers above and below an insulating layer, the insulating layer is composed of insulating layers having different relative dielectric constants of 2 or more, and does not contact the conductor layer and the conductor layer. The present invention relates to a laminated material characterized by having a relative dielectric constant different from that of an insulating layer. The relative dielectric constant of the insulating layer in contact with the conductor layer is preferably 2 times or more or 3/4 times or less that of the insulating layer not in contact with the conductor layer. It is preferable that the dielectric constant of the insulating layer in contact with the conductor layer is 10 to 50 or 1.5 to 3. Furthermore, the present invention relates to a printed wiring board containing a laminated material.

  According to the present invention, since at least two types of insulating materials having different relative dielectric constants are used, any specific dielectric constant can be used within the range of the maximum and minimum relative dielectric constants of each of the laminated materials for electrical insulation used. It is possible to easily provide a laminating material having a rate and a printed wiring board.

  Hereinafter, the best mode for carrying out the invention will be described in detail. The present invention is an electrically insulating laminated material obtained by laminating at least two types of insulating materials having different relative dielectric constants and positively controlling the dielectric constant by a material disposed on a portion in contact with a conductor. As a laminated material for electrical insulation and a printed wiring board having an arbitrary relative dielectric constant obtained by changing the combination of the above, good characteristics are obtained.

  The laminated material of the present invention includes an insulating layer and conductor layers above and below the insulating layer. The insulating layer is not particularly limited as long as it is formed from an insulating material that does not significantly impair the required characteristics as a laminated material for electrical insulation and a printed wiring board to be manufactured. As the insulating material, for example, a laminated material for electrical insulation such as coated cloth, coated paper, prepreg, adhesive sheet, and copper foil with resin may be used.

  When the insulating material contains a resin, the resin is not particularly limited, such as a thermosetting resin or a thermoplastic resin, but is preferably an epoxy resin, a urea resin, a melamine resin, a phenol resin, etc. It is particularly preferable to use it for the main curing system. These can be used alone or in combination.

  The epoxy resin is not particularly limited. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin, naphthalenediol type epoxy resin, phenol novolac type epoxy resin, cresol novolak Type epoxy resin, bisphenol A novolak type epoxy resin, cycloaliphatic epoxy resin, glycidyl ester resin, glycidyl amine resin, heterocyclic epoxy resin (triglycidyl isocyanurate, diglycidyl hydantoin, etc.) and these were modified with various materials Modified epoxy resins can be used.

  In addition, halides such as bromides and chlorides can also be used. Furthermore, two or more of these epoxy resins can be used in appropriate combination. In particular, since it is possible to impart high heat resistance and reliability applicable to electric and electronic material applications to the insulating layer, it is necessary to use a phenol novolac type epoxy resin, a cresol novolac type epoxy resin, a bisphenol A novolac type epoxy resin or a halide thereof. desirable.

  The amount of the epoxy resin added is not particularly limited, but is preferably in the range of 16 to 95% by weight in the resin composition excluding the filler in order to obtain a sufficient cured product.

  Moreover, you may add a hardening | curing agent for the purpose of workability improvement, hardening acceleration of the added resin, etc. As the curing agent, a known curing agent such as a phenol, amine, cyanate, acid anhydride, or a compound having a dihydrobenzoxazine ring may be used alone or in combination.

  Specifically, phenolic novolak, cresol novolak, bisphenol A, bisphenol F, bisphenol S, phenolic curing agents having a phenolic hydroxyl group such as melamine-modified novolak type phenol resin, or halogenated curing agents thereof, dicyandiamide And amine-based curing agents.

  The compound having a dihydrobenzoxazine ring can be easily synthesized by heating and reacting phenols, amines and aldehydes in an appropriate solvent such as methyl ethyl ketone and removing the solvent and water.

  Phenol, cresol, bisphenol A, bisphenol F, etc. can be used as the phenol, aniline, diaminobenzene, etc. can be used as the amine, and formaldehyde, paraform, etc. can be used as the aldehyde. .

  Specifically, 1 equivalent of phenol and 1 equivalent of aniline and 2 equivalents of formaldehyde are mixed in, refluxed, cooled at an arbitrary reaction rate, and further, solvent and moisture, and in some cases, unreacted. By removing the reactant, a resin having a desired dihydrobenzoxazine ring can be obtained.

  In addition, the epoxy resin and the curing agent used in the present invention can be used after appropriately reacting in advance. The addition amount of the curing agent is not particularly limited as long as it does not significantly inhibit the curing reaction of the resin composition, and is preferably in the range of 2 to 73% by weight in the resin composition excluding the filler.

  In addition to the purpose of increasing the relative dielectric constant, one or more kinds of fillers can be added for the purpose of increasing the rigidity and decreasing the thermal expansion, and these are not particularly limited to inorganic and organic. The inorganic filler is not particularly limited. For example, metal oxides such as molybdenum oxide, zinc oxide, and magnesium silicate, metal hydroxides such as aluminum hydroxide and magnesium hydroxide, alumina, silica, talc, mica, Calcium silicate, potassium silicate, calcined clay, titanium oxide, barium sulfate, strontium titanate, calcium titanate, barium titanate, aluminum oxide, magnesium carbonate, calcium carbonate, barium carbonate, etc. A compound such as an oxide composed of a plurality of elements such as molybdenum, zinc, calcium, phosphorus, aluminum, potassium, silicon, and magnesium may be used, or a plurality of the above compounds may be used in combination.

Furthermore, the above resin composition contains known pigments, dyes, adhesion assistants, antioxidants, curing accelerators, flame retardants, flame retardant assistants, organic solvents and the like as long as the characteristics as a printed wiring board are not impaired. Can be added.
The insulating layer is composed of two or more insulating layers having different relative dielectric constants, and the relative dielectric constant of the insulating layer is different from that of the insulating layer in contact with the conductor and that of the insulating layer not in contact with the conductor. Although not particularly limited, the relative dielectric constant of the insulating layer in contact with the conductor layer is preferably not less than 2 times or not more than 3/4 times that of the insulating layer not in contact with the conductor layer.
The dielectric constant of the insulating layer that does not contact the conductor layer is preferably 4 to 5, which is the relative dielectric constant of a general organic insulating material. Specifically, it is not particularly limited as long as the required characteristics are not impaired, but in consideration of cost and the like, a glass epoxy insulating material is preferable, and an FR-4 base material having a relative dielectric constant of 4 to 5 is particularly mentioned.
When the relative dielectric constant of the insulating layer not in contact with the conductor layer is more than twice that of the insulating layer in contact with the conductor layer, the relative dielectric constant of the high dielectric material is 10 to 10. 50 is preferable and 20-50 is more preferable. Moreover, when the relative dielectric constant of the insulating layer in contact with the conductor layer is 3/4 or less that of the insulating layer not in contact with the conductor layer, the relative dielectric constant of the low dielectric material is preferably from 1.5 to 3, Is more preferable. Specifically, there is no particular limitation as long as the required characteristics are not impaired. For example, MCF-HD-45, MCF-HD-30, MCF-HD-20, MCF-7000LX (manufactured by Hitachi Chemical Co., Ltd., respectively, dielectric constant) 45, 30, 20, 2.8 (1 MHz)), GDN-67N (manufactured by Hitachi Chemical Co., Ltd., relative permittivity 10.2 to 10.6 (1 MHz)), BC12TM, BCT16T (manufactured by Mitsui Kinzoku Co., Ltd.) And a resin layer of a copper foil with resin such as a relative dielectric constant of 10 and 30 (1 MHz), respectively.
The thickness of the insulating material between the conductors and the proportion of the same insulating material in the portion in contact with the insulating layer in the conductor are not particularly limited as long as the desired required characteristics can be obtained. 1% or more and 40% or less, more preferably 3% or more and 30% or less, and further preferably 5% or more and 20% or less.

The material of the conductor layer is not particularly limited, but copper, aluminum, iron and the like are preferable, and copper is most preferable. Moreover, a printed wiring board can also be manufactured by etching away the unnecessary part of metal foil of the metal-clad laminated board obtained by combining this insulating material and metal foil, and heat-pressing suitably.
Also, a printed wiring board made from a general metal-clad laminate is used, and at least two types of insulating materials such as prepregs with different dielectric constants, metal foils with resin, or adhesive films are combined on the outside. A printed wiring having at least one insulating layer in which the dielectric constant is positively controlled by the material of the portion in contact with the conductor in the present invention by laminating metal foil as necessary, laminating appropriately, heating and pressing A plate can also be produced.

  If necessary, these printed wiring boards, prepregs, resin-added metal foils or adhesive films, and metal foils may be appropriately laminated alone or in combination, and heated and pressed to produce multilayer printed wiring boards. it can. In the production of these prepregs, laminates, resin-coated copper foils, adhesive films, and printed wiring boards, ordinary coating, lamination, and circuit processing steps in the industry can be applied.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not restrict | limited to these Examples. In the examples and comparative examples, the following wiring board materials were used.
(Prepreg: made by Hitachi Chemical Co., Ltd.)
・ GEA-67BE (JAJH) Relative permittivity 4.9 (1 MHz) Nominal thickness 0.1 mm Text abbreviation JAJH
・ GEA-67BE (JRPJ) Relative permittivity 4.9 (1 MHz) Nominal thickness 0.06 mm Abbreviated text JRPJ

(Copper foil with resin: manufactured by Hitachi Chemical Co., Ltd.)
Insulation layer thickness 20μm Copper foil Low profile foil 12μm
MCF-HD-45 Relative permittivity 45 (1 MHz) Text abbreviation HD45
MCF-HD-30 Relative permittivity 30 (1 MHz) Text abbreviation HD30
・ MCF-HD-20 Relative permittivity 20 (1MHz) Text abbreviation HD20
-MCF-7000LX Relative permittivity 2.8 (1MHz) Text abbreviation 7000LX

Examples 1-6, Comparative Examples 1-5
After superimposing various materials with the structure shown in Table 1, an evaluation substrate was produced by heating and pressing under conditions of a degree of vacuum of 40 hPa, a hot plate temperature of 185 ° C., and a product pressure of 3 MPa. However, due to the structure of the evaluation board, in order to stack multiple copper foils with resin, if there is a possibility that copper may enter between the layers, press once until the copper foil becomes the outermost layer and etch the copper foil After removing the resin alone, the outer layer portion was further laminated and heated and pressed. Moreover, when the laminated body which laminated | stacked the material shown in Table 1 does not have copper foil in an outermost layer, copper foil was laminated | stacked on outermost layer and it was set as the evaluation board | substrate. As the copper foil, a copper foil having a thickness of 12 μm (F2-WS, manufactured by Furukawa Circuit Foil Co., Ltd.) was used.
The dielectric constant was measured by the JIS method and the triplate method. In the JIS method, the dielectric characteristics of 1 MHz were measured, and in the triplate method, the dielectric characteristics of 1, 3, 5 GHz were measured. The measurement of the JIS method was performed according to the following procedure. Based on JIS C6481 1996, measurement was performed with an LCR meter (4284A manufactured by Hewlett-Packard Japan) under the conditions of a main electrode diameter of 30 mm, normal state, and 1 MHz.

  The measurement of the triplate method was performed according to the following procedure. The measurement apparatus was a vector type network analyzer (HP-8722C manufactured by Hewlett-Packard Japan) and measured by a triplate structure linear line resonance method. The sample for measurement was produced by the following procedure.

  First, the copper foil on one side of one laminated board (the above-mentioned evaluation board) was removed leaving a 0.8 mm straight line (line length 20 mm), and the back surface was used as a ground layer leaving copper on the entire surface. The other laminated plate was etched on the entire surface of one side of the copper foil, and the back surface was a ground layer. Then, the ground layer of these two laminates was placed outside to form a superposed strip line, which was used as a test piece. All measurements were performed at 25 ° C.

  As shown in Table 1, it is clear from Examples 1-6 and Comparative Examples 1-5 that base materials having different relative dielectric constants can be produced by simply combining organic insulating materials having different relative dielectric constants. It is.

From the test results of Examples 1 and 2, it is clear that substrates having different relative dielectric constants can be manufactured by adjusting the thickness of the material layer in contact with the conductor. Further, by comparing Example 1 and Example 6, even if the same material is used, a material having a relative dielectric constant characteristic of the insulating layer in contact with the conductor, that is, a relative dielectric constant of the insulating layer not in contact with the conductor layer It was confirmed that the effect was high when an insulating layer that was 2 times or more or 3/4 times or less of the above was used.
Specifically, in Example 1 and Example 6, the same value was obtained in the JIS method for measuring the entire relative dielectric constant, but a difference occurred in the triplate method. The triplate method is considered to be able to more accurately measure the influence of materials when current and signals flow. The JIS method determines the influence of electrical signals on insulating materials when manufacturing actual electrical and electronic circuits. More accurately. That is, as a whole, even when the relative permittivity is measured as the same, it has been confirmed that the effect is very high when a material having a characteristic relative permittivity is used for the portion in contact with the conductor.

  According to the present invention, the relative dielectric constant can be changed to a desired value by arranging the material used for the portion in contact with the conductor. In addition, it is possible to reduce the manufacturing cost by using a relatively inexpensive laminated material for electrical insulation such as a so-called general FR-4 prepreg as a part of the configuration. Therefore, the superiority of the present invention is clear.

Claims (6)

  A laminated material having conductor layers above and below the insulating layer, wherein the insulating layer is composed of two or more insulating layers having different relative dielectric constants, and an insulating layer in contact with the conductor layer and an insulating layer not in contact with the conductor layer; Laminated materials characterized by having different relative dielectric constants.   The laminated material according to claim 1, wherein the dielectric constant of the insulating layer in contact with the conductor layer is at least twice the relative dielectric constant of the insulating layer not in contact with the conductor layer.   The laminated material according to claim 1, wherein the dielectric constant of the insulating layer in contact with the conductor layer is 3/4 or less of the relative dielectric constant of the insulating layer not in contact with the conductor layer.   The laminated material according to claim 2, wherein the insulating layer in contact with the conductor layer has a relative dielectric constant of 10 to 50.   The laminated material according to claim 3, wherein a dielectric constant of an insulating layer in contact with the conductor layer is 1.5 to 3.   The printed wiring board containing the laminated material in any one of Claims 1-6.