JP5323780B2 - Low-inductive-electricity resin varnish composition for laminated substrate and process for producing the same - Google Patents

Description

  The present invention is a new resin varnish composition for laminates suitable for use as a high-performance electric circuit board material capable of achieving a flame-resistant UL94 V-0 test having low dielectric constant, high thermal stability and low moisture absorption characteristics. About.

With the progress of science and technology, many computer information industries, information communication industries, and consumer electronic products are changing rapidly. Looking at the electronics industry as a whole, the characteristics of its development are as follows.
1. Frequency of use is gradually increasing.
2. Manufacturing technology level is also getting higher.

There is a demand for printed circuit boards that must be environmentally friendly while developing toward low dielectrics, low thermal expansion, multiple layers, and high heat resistance. For this reason, electronic and information communication products tend to be light, thin, compact, highly reliable, multifunctional and satisfy environmental protection requirements. As the frequency of use of wireless Internet and information communication equipment increases, the need for high-frequency substrates is increasing in the future. In simple terms, the materials used for high-frequency information communication boards must be able to withstand high-speed data transmission, have no loss of data (data signals) in the process of transmission, and must not be disturbed. Therefore, when selecting a high-frequency information communication device, it is necessary to consider some basic characteristics as follows.
(1) The dielectric constant is small and stable.
(2) Dielectric consumption factor is small.
(3) Low water absorption.
(4) Good anti-chemical properties.
(5) Good heat resistance.

  The electrical characteristics of the printed circuit board material are determined by the three main combination main materials i) resin, (ii) filler, and (iii) reinforcing material. The FR-4 (Tg140 ° C) board standard that combines epoxy resin (eg, NPEB454A80 from Nanya Plastics Corporation) and glass (E glass), which is currently widely used as a resin, has a low dielectric constant (Dk) value 4.6 cannot meet the requirements of the high-frequency transmission field. Resins such as bismaleimide triazine resin (BT), cyanate ester resin, and polytetrafluoroethylene (PTFE) are being developed one after another. The manufacturing process, processing conditions, and the like are not widely used because they have a large difference from the current substrate processing and manufacturing process and cannot be used as they are.

The development of printed circuit board is light, thin, small, precise and high frequency, and the resin material used has excellent electrical characteristics so that there is no loss or interference of data (data signal) in the transmission process. It is necessary to have. In addition, the newly developed low dielectric resin varnish composition can be operated with currently used processing, manufacturing process operations and equipment, and meets the environmental protection requirements. Has become an important issue that must be overcome.

  From the above problems, the inventors of the present technology have discovered a saturated ring-shaped resin having a framework of a saturated ring structure in chemical structure through many years of research and testing. These are resin varnish compositions that can effectively lower the thermal expansion coefficient, dielectric constant and dielectric loss factor of the substrate, and have excellent low dielectric constant Dk and low dielectric loss coefficient Df electrical characteristics. In addition, it is possible to manufacture substrates that meet different needs by blending various curing agents in current equipment and processing and manufacturing processes.

  The main object of the present invention is to provide a circuit board with low dielectric constant, low dielectric loss, low moisture absorption and high thermal stability, which is a low-cost naphtha decomposition by-product dicyclopentadiene (DCPD). As a raw material, a novolac-type phenol resin (DCPD-PN) containing a DCPD structure is obtained by reaction synthesis with a phenol compound, which is a rigid, aliphatic, cyclic skeletal three-dimensional structure of the raw material itself. Also, if this DCPD resin is reacted with a dihydrobenzoxazine (BX) resin or an epoxy resin, a dicyclopentadiene-dihydrobenzoxazine resin (Dicyclopentadiene-Dihydrobenzoxazine, DCPD-BX) or a DCPD epoxy resin (Phenol) Novolac Epoxy, DCPD-PNE) to create a low dielectric, high thermal stability, low hygroscopic circuit board, and easily manufacture and process copper foil substrates with currently used equipment and processing conditions .

The varnish combination made from the above-mentioned new low dielectric resin is: (A) Novolac type phenol resin with DCPD (DCPD-PN); (B) One or more types of epoxy resin or epoxy resin with DCPD (DCPD-PNE) ); (C) DCPD-BX resin with DCPD; (D) Resin varnish composition for laminates according to the present invention comprising (A), (B) , (C) or (B) + (C) and (D) are mixed by adding a solvent in a certain proportion. That;
Main agent: DCPD epoxy resin (DCPD-PNE) is synthesized by reacting DCPD-PN raw material with Epichlorohydrin (ECH) in the presence of a certain equivalent ratio of NaOH. DCPD-BX resin is synthesized by adding a certain equivalent ratio of polyacetal and aniline to the raw material of DCPD-PN.
Hardener: Hardener NPEH-710S or 710H from Nanya Plastics Corporation, and DCPD-PN can be used as a hardener to increase DCPD content.
Flame retardants: At present, conventional flame retardants are classified into three types. One traditional brominated flame retardant is tetrabisphenol A (TBBA). Second, the phosphoric flame retardant is a phosphoric acid ester compound (DOPO), and the third is an inorganic additive type flame retardant Al ₂ O ₃ , ATH, or the like, but it may not be added.

The resin composition for new laminates of the present invention is produced by the following procedure.
1. First, (A) dicyclopentadiene novolac phenol resin (DCPD-PN) is produced by reacting a naphtha decomposition product dicyclopentadiene having a curable aliphatic cyclic stereoskeleton with a phenol compound.
2. DCPD-PN with DCPD component is epoxidized to epichlorohydrin (ECH) to form dicyclopentadienephenol epoxy resin (DCPD-PNE, also called Resin 1). Or
3. DCPD-PN is reacted with a mixture of primary amines with monofunctional groups and primary amines with bifunctional groups and formaldehyde or polyacetal compounds to form dicyclopentadiene-dihydrobenzoxazine resin (DCPD-BX) Then, another name resin 2 is produced.

  Since the resin composition for a new laminate of the present invention has a saturated polycyclic skeleton structure, it has better chemical and physical properties than general epoxy resins. After immersing the glass fiber cloth in this resin varnish composition and heat-pressure curing, an electric circuit board having excellent electrical properties, high thermal stability and low hygroscopic properties can be obtained. Applied to high-performance electric circuit boards.

The present invention is a kind of low dielectric resin varnish composition for laminated substrates, the resin composition of which is: (A) dicyclopentadiene-novolak type phenolic resin (DCPD-PN); or (B) one or various kinds Epoxy resin or dicyclopentadiene-phenol epoxy resin (DCPD-PNE); or (C) dicyclopentadiene-dihydrobenzoxazine (DCPD-BX) resin; or (B) + (C) resin and (D) It is made by mixing a flame retardant, curing agent, curing accelerator and solvent in a certain proportion.
Among them, (A) dicyclopentadiene-novolak type phenol resin (DCPD-PN) having a DCPD component is obtained by reacting (a) dicyclopentadiene with (b) a phenol compound, and the structural formula thereof is As in (I):

After the reforming or conversion reaction, various types are obtained, and the details of the synthesis are as follows.
Synthesis of DCPD-PN:
Heating pack, thermostat, in 5L4-neck glass reaction vessel equipped with an electric mixer and a cooling tube were placed a Lewis acid catalyst (AlCl _3), which accounts for 2 wt% of phenolic compounds and phenol weight of 940 g, the temperature is Mix until 110 ° C and further raise the temperature to 120 ° C, then add 132 g of DCPD in a drop-wise manner and let the temperature react for 4 hours. Then, neutralization solution of sodium hydroxide is added, salts and catalyst are removed from the reaction solution with fresh water, and finally, excess reactant is removed at 180 ° C. under a pressure of 70 torr to obtain a DCPD-PN product.

(A) Dicyclopentadiene that makes DCPD-PN is a by-product of naphtha decomposition, and its (b) phenolic compounds are generally phenol, O (ortho) cresol, bisphenol A (Bisphenol-A), bisphenol F ( Bisphenol-F), bisphenol-S (Bisphenol-S), phenol resin, etc. are best bisphenol A or phenol resin.

The solvent used for synthesizing DCPD-PN is not particularly limited and may be any solvent that can dissolve each reactant. However, hydrocarbon solvents such as toluene and xylene are optimal.
In the present invention, in order to increase the DCPD content, DCPD-PN can be added and used as a curing agent. Therefore, the following phenol resin curing agent can also be used. : Polyvalent amines, Polyvalent carboxylic acids, Dicyanodiamide, Anhydrides, Novolac-type phenolic resin (Phenol Novolac, abbreviated as PN), O (ortho) cresol novolac resin ( Cresol Novolac (abbreviation CN), melamine novolac type phenolic resin (Melamine Phenol Novolac, abbreviated MPN), bisphenol A novolac resin (BPA Phenol Novolac, abbreviated BPA-PN), tetraphenol novolac resin (Tetra-Phenol Novolac, abbreviated TPN), etc. .

Component (B) in the resin varnish composition of the present invention or one or more types of epoxy resin or dicyclopentadiene epoxy resin (DCPD-PNE) containing a DCPD component; It is an epoxy resin made by reacting with hydrin. Its structural formula is as follows:

Synthesis of DCPD-PNE (Resin 1):
Put 500g of DCPD-PN and 2927.2g of epichlorohydrin in a 5L 4-neck glass reactor equipped with a heating pack, automatic temperature controller, electric mixer and cooling tube, and raise the temperature to 55 ° C. Dissolve and 281 g of sodium hydroxide is added dropwise for 4-6 hours. The temperature is then raised to 78 ° C. and allowed to react for 1 hour under 110 Torrs pressure, and finally the excess reactant is removed under 180 ° C. and 70 torr pressure to obtain the DCPD-PNE product.

  The epoxy resin mentioned here is bisphenol A (BPA) type epoxy resin a, brominated BPA type epoxy resin, phenol type epoxy resin and a. Phosphate ester type epoxy resin.

(C) dicyclopentadiene-dihydrobenzoxazine resin (DCPD-BX) having a DCPD component, another resin 2 is (1) dicyclopentadiene-novolak type phenol resin (DCPD-PN) component A above; (2 ) Methylamine, dimethylamine, aniline, toluidine, anisidine, diamidediphenylmethane, aliphatic or aromatic amine compounds ; (3) formed by reacting three compounds such as formaldehyde or polyacetal; Its structural formula is as follows (III):

After the modification, it will be of various types, and the details of the synthesis are as follows.
Synthesis of DCPD-BX (Resin 2):
In a 5L 4-neck glass reactor equipped with a heating pack, automatic temperature controller, electric mixer and cooling tube, put 480g of DCPD-PN, 486g of polyacetal, add 500g of toluene, mix and dissolve, When 279 g of aniline was slowly added dropwise to the above solution, the temperature was adjusted to 60-110 ° C., reacted for 4-6 hours, and the solvent and unreacted substances were removed at 180 ° C. under 70 torr pressure. A solid dicyclopentadiene-dihydrobenzoxazine resin is obtained.

The compound used to synthesize DCPD-BX resin (1) is (A) dicyclopentadiene novolac type phenol resin (DCPD-PN) having a DCPD component.
(2) uses methylamine, dimethylamine, aniline, toluidine, and anisidine, but may be an aliphatic or aromatic amine compound. Optimum is aniline or diamidodiphenylmethane.

  (3) As formaldehyde or polyacetal compound, formaldehyde, polyacetal or formaldehyde vapor is generally used, but polyacetal is most suitable.

  The solvent is not particularly limited as long as it can dissolve each reactant. Hydrocarbon solvents such as toluene and xylene are optimal.

  The resin varnish composition component (D) of the present invention contains a flame retardant and a curing accelerator. The flame retardant is mainly bromine-based and phosphorus-based resins, and inorganic filler flame retardants can also be used. Brominated flame retardants: Tetrabisphenol A (TBBA), NPEB-485A80 (trade name, produced by Nanya Plastics Corporation, bromine content 18-21%), NPEB-454A80 (trade name, produced by Nanya Plastics Corporation) Production, bromine content 18-21%).

  Phosphorus flame retardants are DOPO (9,10-Dihydro-9-Oxa-10-Phosphaphenanthrene -10-Oxide), DOPO-HQ, DOPO-Phenol Novolac Epoxy Resin (DOPO-PNE), DOPO-Hydroquinone-Phenol Novolac Epoxy Resin (DOPO-HQ-PNE). Inorganic filler flame retardants are mainly aluminum hydroxide, silicon dioxide, barium sulfate, aluminum oxide, boron nitride and the like.

  Other curing accelerators that can also be used in the present invention include tertiary phosphines, tertiary amines, quaternary phosphonium salts, quaternary ammonium salts and imidazole compounds. Among them, the tertiary phosphine includes triphenyl phosphine and the like. For tertiary amines, trimethylaniline, triethylamine, tributylamine, dimethylethanolamine, etc .; for quaternary phosphonium salts, tetrabutylphosphonium bromide, tetraphenylphosphonium bromide, ethyltriphenylphosphonium bromide, propyltriphenyl group phosphonium chloride And phosphonium salts containing halogen compounds such as butyltriphenyl group phosphonium bromide. Quaternary ammonium salts include quaternary ammonium salts containing halogen compounds such as tetramethylammonium bromide, tetraethylammonium bromide, tetrabutylammonium bromide, triethylbenzidinemethylammonium bromide, triethylbenzineethylammonium bromide; Imidazole compounds include 2-methylimidazole, 2-ethylimidazole, 2-dodecylimidazole, 2-phenylimidazole, 4-methylimidazole, 4-ethylimidazole, 4-dodecylimidazole, 2-ethyl-4-methylimidazole, 2 Among them, 2-methylimidazole or 2-ethyl-4-methylimidazole is most suitable, such as -ethyl-4-carboxylic group methylimidazole. These curing accelerators can be used alone or in combination of two or more at the same time. The amount used is 0.01 to 1 PHR of the total resin amount, and the optimum amount is 0.04 to 0.15 PHR.

  The present invention is a novel low dielectric resin composition synthesized by synthesizing a resin having a cyclic structure, and (A) DCPD-PN content is 0 to 50 wt% of the total resin amount; (B) DCPD-PNE (resin 1) content Is 13 to 60 wt% of the total amount of resin; (C) DCPD-BX (resin 2) content is 30 to 50 wt% of the total amount of resin; (D) The flame retardant content is 22 to 32 wt% of the total amount of resin; 0.01 to 1 PHR; the viscosity of the varnish is adjusted using a solvent and mixed. The total resin amount is the total resin amount of the low induction electric power resin varnish composition for laminated substrates. Solvents include organic aromatic solvents, protic solvents, ketone solvents, ether solvents and ester solvents (suitable solvents are toluene, N, N-dimethylformamide, acetone, methyl ethyl ester, 1-methoxy-2 -Propyl alcohol, ethyl acetate, etc. Resin 1 and Resin 2 can be used alone or at the same time mixed or mixed with other epoxy resins. After soaking the fiber cloth in the above composition and heating again, the soaked glass fiber cloth is taken out and dried to a prepreg, and copper foil is placed on one or both sides of the prepreg, and one or many prepregs are added. A copper foil substrate can be formed by overlapping heating and pressing, and the curing temperature range of the resin varnish composition is 30 ° C. to 300 ° C., preferably 150 ° C. to 210 ° C.

Hereinafter, the present invention will be described in detail by way of examples. The codes and components of the examples and comparative examples are as follows:
Resin 1: (B) DCPD-PNE resin of the present invention, epoxy equivalent is 270 to 230 g / eq.
Resin 2: (C) DCPD-BX resin of the present invention, nitrogen content 6.2 wt%
Resin 3: Brominated resin produced by Nanya Plastics Corporation, trade name is NPEB-485A80.
Resin 4: Phosphorus resin (DOPO-638) produced by Nanya Plastics Corporation, product name is 210A70.
Resin 5: Phosphorous resin (DOPO-HQ-638) produced by Nanya Plastics Corporation, product name is 220A70.
Hardener 1: Phenolic resin produced by Nanya Plastics Corporation, trade name is 710HA65.
Hardener 2: Phenolic resin produced by Nanya Plastics Corporation, trade name is 710SA65.
Curing agent 3: DCPD-PN of the present invention.
Flame retardant 1: Bromine-containing flame retardant, tetrabisphenol A (TBBA).
Flame Retardant 2: Phosphorus containing flame retardant produced by Nippon Daihachi Chemical Company, trade name is PX-200.
Flame retardant 3: Aluminum hydroxide (ATH) filler.
Flame retardant 4: Silicon dioxide (SiO ₂ ) filler.
Curing accelerator 2MI: 2-methylimidazole, 14.2 wt% is soluble in DMF.
Glass fiber cloth 7628: Glass fiber cloth produced by Nanya Plastics Corporation.

Example 1
DCPD-PNE is used as the main resin, and the curing agent 710HA65 and the flame retardant TBBA are blended and used. Details of the blending composition are shown in Table 1. Adjust to a varnish resin composition with a solid content of 65% with an acetone solvent, immerse the 7628 glass fiber cloth in the varnish resin liquid, and when the temperature of the impregnation machine reaches 170 ° C, take it out and dry it for several minutes The prepreg melt viscosity after drying is 4000 to 10000 poise. Finally, 8 sheets of prepreg are put between 35-μm thick copper foil, pressure of 25 kg / cm ² is applied, and the temperature is adjusted as follows:

After hot pressing, a copper foil substrate with a thickness of 1.6 mm is produced. The detailed functions of this composition are shown in Table 1.

Example 2
Although the same as Example 1, the curing agent is changed to 710SA65, and the detailed functions of the resulting composition are shown in Table 1.

Example 3
Although the same as Example 1, the curing agent is replaced with DCPD-PN, and the detailed functions of the resulting composition are shown in Table 1.

Example 4
DCPD-PNE is used as the main resin, curing agent 710HA65 is blended, the flame retardant is changed to PX-200 phosphorus flame retardant, and the details of the blend composition are as shown in Table 1. The production procedure is the same as that of the copper foil substrate of Example 1, and the detailed functions of the resulting composition are shown in Table 1.

Example 5
Although the same as in Example 4, the curing agent is changed to 710SA65, and the detailed functions of the resulting composition are shown in Table 1.

Example 6
Although the same as Example 4, the curing agent is replaced with DCPD-PN, and the detailed functions of the resulting composition are as shown in Table 1.

Example 7
DCPD-BX is used as the main resin, DCPD-PNE resin is adjusted to an appropriate amount, curing agent 710HA65 is added, flame retardant is aluminum hydroxide and silicon dioxide, and the details of the composition are as shown in Table 1. It is. The manufacturing procedure is the same as that of the copper foil substrate of Example 1, but the detailed functions of the resulting composition are shown in Table 1.

Example 8
Although the same as in Example 7, the curing agent is changed to 710SA65, and the detailed functions of the resulting composition are shown in Table 1.

Example 9
Although the same as in Example 7, the curing agent is replaced with DCPD-PN, and the detailed functions of the resulting composition are shown in Table 1.

Example 10
DCPD-BX is used as the main resin, phosphorous resin 210A70 is blended, and curing agent 710HA65 is blended to produce a halogen-free substrate. The details of the blending composition are shown in Table 2. The manufacturing procedure is the same as that of the copper foil substrate of Example 1, but the detailed functions of the resulting composition are shown in Table 2.

Example 11
Although the same as in Example 10, the curing agent is changed to 710SA65, and the detailed functions of the resulting composition are shown in Table 1.

Example 12
Although the same as Example 10, the curing agent is replaced with DCPD-PN, and the detailed functions of the resulting composition are shown in Table 1.

Example 13
DCPD-BX is used as the main resin, phosphorous resin 220A70 is blended, and curing agent 710HA65 is blended to produce a halogen-free substrate. The details of the blending composition are shown in Table 2. The manufacturing procedure is the same as that of the copper foil substrate of Example 1, but the detailed functions of the resulting composition are shown in Table 2.

Example 14
Table 1 shows the same detailed function of the resulting composition except that the curing agent is changed to 710SA65.

Example 15
Table 1 shows the detailed functions of the composition obtained by replacing DCPD-PN with the curing agent, as in Example 13.

Comparative Example 1
A brominated epoxy resin (Nippon Plastics Corporation brominated epoxy resin, trade name NPEB-485A80) is used as a main material resin, a curing agent 710HA65 is blended, and the details of the blended composition are shown in Table 2. The production procedure is the same as that of the copper foil substrate of Example 1, and the detailed functions of the resulting composition are shown in Table 2.

Comparative Example 2
Table 1 shows the detailed functions of the resulting composition except that the curing agent is changed to 710SA65.

Comparative Example 3
Table 1 shows the detailed functions of the composition obtained by replacing DCPD-PN with the curing agent, as in Comparative Example 1.

Survey explanation
1. Varnish gelation time (sec):
Take 0.3ml resin varnish on a 170 ° C heating plate and measure the time of gelatinization.
2. Glass transition temperature (℃):
Tested using a differential scanning calorimeter (DSC) with a heating rate of 20 ° C / min.
3. Flame resistance:
Cut the sample into 0.5in x 4.7in rectangles, burn with a blue flame of 2cm in height for 10 seconds, remove it, bake it twice, record the time from removal from the flame until it disappears naturally.
4. Water absorption rate (%):
The sample is heated in a pressure cooker at 120 ° C. and 2 atm for 30 minutes.
5. Induction power loss (1GHz):
Take a 25cm ² square sample from the etched substrate, bake at 105 ° C for 2 hours, and then measure the thickness of the sample at three locations using a measuring instrument. Again, sandwich the sample with a dielectric surveying instrument, measure the three points, and take the average value.
6. Inductive power (1GHz):
Take a 25cm ² square sample from the etched substrate, bake at 105 ° C for 2 hours, and then measure the thickness of the sample at three locations using a measuring instrument. Again, sandwich the sample with a dielectric surveying instrument, measure the three points, and take the average value.

  Substrates made using DCPD-PNE with the formulations of Examples 1-6 have characteristics of inductive power coefficients of 4.18-4.21 and inductive loss factors of 0.012-0.016. In the formulations of Examples 10-15, the substrates made using DCPD-BX have the characteristics of inductive conductivity coefficients 4.15-4.32 and inductive loss factors 0.012-0.016. In the formulations of Examples 7 to 9, DCPD-PNE and DCPD-BX are used at the same time, and the produced substrate has characteristics of a low induction electric power coefficient of 3.89 to 3.92 and a low induction electric loss factor of 0.008 to 0.009. This is clearly superior to the inductive conductivity coefficients of 4.4 to 4.7 and the inductive loss factor of 0.025 to 0.03 for substrates made with other resin blends that do not have a DCPD structure.

From Examples, Table 1 and Table 2, after immersing and curing the glass fiber cloth in the varnish resin containing DCPD structure, it must have low moisture absorption, low induction electric power coefficient and low induction electric loss factor. I understand. A substrate obtained by compounding DCPD-PN as a curing agent in a resin and compressing it can effectively lower the induction electric power coefficient and the induction electric loss factor. Furthermore, when DCPD-BX resin was added, the resin content of DCPD structure increased, so the flame retardant filler in the resin varnish composition further reduced the induction electric power and reached the 94V-0 flame resistance standard. It has thermal stability.

Claims (9)

(A) dicyclopentadiene-novolak type phenolic resin (DCPD-PN) occupying 0 to 50% by weight of the total resin amount,
Or (B) a dicyclopentadiene epoxy resin (DCPD-PNE) having a D CPD component that accounts for 13 to 60% by weight of the total resin amount,
Or (C) dicyclopentadiene-dihydrobenzoxazine resin (DCPD-BX) occupying 30-50% by weight of the total resin amount,
Or (B) and (C) mixed resin;
(D) a flame retardant, a curing agent or accelerator, and a low inductive conductivity resin varnish composition for laminate substrate characterized by comprising a solvent are mixed at a fixed proportion,
The (A) dicyclopentadiene-novolak type phenol resin (DCPD-PN) is obtained by reacting dicyclopentadiene with a phenol compound, and the structural formula thereof is as shown in the following formula (I):

(A) dicyclopentadiene-novolak type phenolic resin (DCPD-PN) is used as a curing agent to increase the content of the dicyclopentadiene,
A low-inductive-electricity resin varnish composition for laminated substrates, comprising a resin obtained by mixing (B) and (C). The (B) dicyclopentadiene epoxy resin (DCPD-PNE) having a dicyclopentadiene component is obtained by reacting a dicyclopentadiene-novolak type phenol resin with epichlorohydrin, and the structural formula thereof is the following formula ( It is as II), The low induction electric power resin varnish composition for laminated substrates of Claim 1 characterized by the above-mentioned.

The (C) dicyclopentadiene-dihydrobenzoxazine resin (DCPD-BX) includes (1) a dicyclopentadiene-novolak type phenol resin, (2) aniline or diamidodiphenylmethane, and (3) formaldehyde or a polyacetal compound. The low induction electric charge resin varnish composition for laminated substrates according to claim 1 or 2, wherein the structural formula is as shown in the following formula (III).

  The phenol compound is phenol, ortho-cresol, bisphenol A (Bisphenol-A), bisphenol F (Bisphenol-F), bisphenol S (Bisphenol-S) or a phenol resin. The low induction electric power resin varnish composition for laminated substrates of any one of Claims 1.   The formaldehyde or polyacetal compound for the synthesis of the (C) dicyclopentadiene-dihydrobenzoxazine resin (DCPD-BX) is formaldehyde, polyacetal, or formaldehyde vapor, according to any one of claims 1 to 4. The low induction electric power resin varnish composition for multilayer substrates described in 1. The low-inductive-electricity resin varnish composition for laminated substrates according to any one of claims 1 to 5, wherein the flame retardant is a resin containing bromine or phosphorus, or an inorganic filler flame retardant. The low-inductive-electricity resin varnish composition for laminated substrates according to any one of claims 1 to 5, wherein the flame retardant is tetrabisphenol A (TBBA) or a tetrabisphenol A type epoxy resin. The low-inductive-electricity resin varnish for a multilayer substrate according to any one of claims 1 to 5, wherein the flame retardant is aluminum hydroxide, silicon dioxide, barium sulfate, aluminum oxide, or boron nitride. Composition. The accelerator according to any one of claims 1 to 8, wherein the accelerator is an imidazole compound (2-methylimidazole, 2MI) or 2-ethyl-4methylimidazole (2E4MZ). The low induction electric power resin varnish composition for multilayer substrates as described in the paragraph.