JPH10264341A - Laminate board for electricity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a laminated board for electricity improved in its warpage and dimensional stability more than a laminate board employing resol type phenol resin being modified by drying oil such as tung oil. SOLUTION: A laminate board for electricity is formed of laminating a prepreg-impregnating resin composition in the base material and being molded through heat-compression includes formaldehyde condensation resin containing tung oil modified novolak type phenol formaldehyde resin and epoxy resin containing dicyclopentadiene phenol type epoxy resin. Also, melamine formaldehyde is included as the described formaldehyde condensation resin. A solid quantity of melamine formaldehyde resin is 5-20 pts.wt. to the total amount of 100 pts.wt. of a solid quantity of tung oil modified novolak type phenol formaldehyde resin and melamine formaldehyde resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric laminate used for electronic equipment, electric equipment and the like.

[0002]

2. Description of the Related Art Conventionally, a phenolic resin composition has been impregnated into a base material such as kraft paper or linter paper as an electric laminate used for a printed wiring board for an electronic device, an electric device, an electric insulating substrate and the like. A phenol resin laminate obtained by laminating prepregs and applying heat and pressure is used. Conventional phenolic resin laminates mainly use a resol-type phenol-formaldehyde resin (hereinafter referred to as a resol-type phenolic resin), but have a drawback that the warpage is large. This is considered to be due to the fact that the resol type phenol resin causes a dehydration condensation reaction at the time of heat and pressure molding. That is, it is considered that the curing shrinkage of the resin caused by the dehydration condensation reaction of the resol-type phenol resin is a factor that increases the warpage of the laminate and decreases the dimensional stability. Therefore, a method of plasticizing a laminate using a resol-type phenol resin modified with a drying oil such as tung oil has been used to improve warpage and dimensional stability, but this is insufficient and further improvement is required. Is desired.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a laminating method using a resol type phenol resin modified with a drying oil such as tung oil. An object of the present invention is to provide a laminate for electric use in which warpage and dimensional stability are improved more than a board.

[0004]

According to a first aspect of the present invention, there is provided an electric laminate obtained by laminating a prepreg obtained by impregnating a base material with a resin composition, followed by heating and press molding. The resin composition comprises a formaldehyde condensed resin containing a tung oil-modified novolak type phenol formaldehyde resin and an epoxy resin containing a dicyclopentadiene phenol type epoxy resin.

According to a second aspect of the present invention, there is provided an electric laminate according to the first aspect, further comprising a melamine formaldehyde resin as the formaldehyde condensation resin.

According to a third aspect of the present invention, there is provided an electric laminate according to the second aspect, wherein the melamine is added to the total of 100 parts by weight of the solid content of the tung oil-modified novolak type phenol formaldehyde resin and melamine formaldehyde resin. The solid content of the formaldehyde resin is 5 to 20 parts by weight.

According to a fourth aspect of the present invention, there is provided an electrical laminate according to any one of the first to third aspects, wherein the electrical laminate also includes a novolak type epoxy resin as the epoxy resin. I do.

According to a fifth aspect of the present invention, there is provided an electric laminate according to the fourth aspect, further comprising a bisphenol A type epoxy resin as the epoxy resin.

According to a sixth aspect of the present invention, there is provided an electric laminate according to the fifth aspect, further comprising a naphthalene type epoxy resin as the epoxy resin.

In the present invention, the resin composition impregnated in the substrate is
Including a formaldehyde condensed resin containing a tung oil modified novolak type phenol formaldehyde resin and an epoxy resin containing a dicyclopentadiene phenol type epoxy resin, compared to a resin composition mainly composed of a tung oil modified resol type phenol resin, The dehydration-condensation reaction at the time of heating and pressing can be suppressed, and the curing shrinkage of the resin is reduced. Therefore, the electric laminate of the present invention has improved warpage and dimensional stability. In addition, the inclusion of the dicyclopentadiene phenol type epoxy resin results in a laminate having good water resistance and the like.

The tung oil-modified novolak-type phenol formaldehyde resin in the present invention refers to a resin obtained by adding formaldehyde to a reaction product of tung oil and phenols to form a novolak under an acidic catalyst. Further, the dicyclopentadiene phenol type epoxy resin indicates a compound represented by the following general formula (1). M in Chemical Formula 1 represents 0 or a positive integer.

[0012]

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[0013]

Embodiments of the present invention will be described.
The electric laminate according to the present invention is an electric laminate obtained by laminating a prepreg obtained by impregnating a base material with a resin composition, and subjecting the prepreg to heat and pressure molding. The substrate is not particularly limited, but is preferably, for example, a cellulose-based paper substrate. Specifically, kraft paper, linter paper, or a paper substrate in which inorganic or organic substances are mixed with kraft paper or linter paper Materials can be used. The resin composition contains a formaldehyde condensed resin containing a tung oil-modified novolak type phenol formaldehyde resin and an epoxy resin containing a dicyclopentadiene phenol type epoxy resin.

The tung oil-modified novolak type phenol formaldehyde resin is a resin obtained by adding formaldehyde to a novolak in the presence of an acid catalyst based on a resin obtained by reacting tung oil with phenols. Here, examples of the phenols include alkylphenols such as phenol and cresol, and bisphenols, and these may be used alone or in combination. Also,
The resin obtained by reacting tung oil with phenols can be obtained by reacting, for example, in the presence of an acid catalyst.

It is preferable that the above-mentioned formaldehyde condensed resin also contain a melamine formaldehyde resin, because the insulation resistance and tracking resistance of the laminate can be improved. In this case, the content is 100 parts by weight of the total solid content of the tung oil-modified novolak type phenol formaldehyde resin and the melamine formaldehyde resin.
It is desirable that the melamine formaldehyde resin has a solid content of 5 to 20 parts by weight. If the amount is less than 5 parts by weight, the effect of improving the insulation resistance and the tracking resistance of the laminate is small. On the other hand, if the amount exceeds 20 parts by weight, the solid content when adjusting the resin varnish for impregnating the base material during prepreg production is reduced. Is difficult to dissolve in the solvent, and in some cases, the melamine formaldehyde resin precipitates, which causes problems such as difficulty in adjusting the viscosity of the resin varnish and controlling the resin content of the prepreg.

The epoxy resin contains a dicyclopentadiene phenol type epoxy resin as an essential component. Here, the dicyclopentadiene phenol type epoxy resin represents a compound represented by the general formula shown in Chemical Formula 1. By making this dicyclopentadiene phenol type epoxy resin an essential component,
The dehydration-condensation reaction at the time of heat-press molding can be suppressed, whereby the curing shrinkage of the resin is reduced, and as a result, the laminate is improved in warpage and dimensional stability and has good water resistance. The content ratio of the dicyclopentadiene phenol type epoxy resin in the epoxy resin is not particularly limited, but the total solid content of the epoxy resin is 10%.
When the amount is 0 parts by weight, it is desirable to contain 30 to 100 parts by weight of a dicyclopentadiene phenol type epoxy resin from the viewpoint of improving dimensional stability and water resistance. In addition, it is preferable to include a novolak-type epoxy resin in addition to the dicyclopentadienephenol-type epoxy resin as the epoxy resin, since the crosslink density of the cured resin is improved and the solder heat resistance is also improved. Further, it is preferable to include a bisphenol A type epoxy resin together with a dicyclopentadiene phenol type epoxy resin and a novolak type epoxy resin as the epoxy resin, because the effect of further reducing warpage is preferable. When the bisphenol A-type epoxy resin is brominated, it is preferable because it also functions as a flame retardant and improves flame retardancy.
When a brominated bisphenol A type epoxy resin is contained, it is possible to reduce the amount of a flame retardant composed of a brominated compound such as tetrabrominated bisphenol A, which is conventionally used, and to further improve the heat resistance of the laminated board. The effect can be achieved. Further, it is preferable to include a naphthalene type epoxy resin together with a dicyclopentadiene phenol type epoxy resin, a novolak type epoxy resin and a bisphenol A type epoxy resin, because the effect of further improving the water resistance is preferable.

Regarding the mixing ratio of the formaldehyde condensed resin and the epoxy resin, the solid content of the formaldehyde condensed resin is preferably 30 to 70 parts by weight with respect to the total of 100 parts by weight of the solids of the formaldehyde condensed resin and the epoxy resin. If the solids content of the formaldehyde condensed resin is less than 30 parts by weight, the effect of reducing the curing shrinkage of the resin is small, and therefore the effect of improving the dimensional stability of the laminate becomes small. This is because the effect of improving the warpage and dimensional stability of the plate is reduced.
In the present invention, the formaldehyde condensed resin and the epoxy resin are mixed or reacted (prereact) to obtain a resin composition.

In producing the prepreg by impregnating the above-mentioned resin composition into the above-mentioned base material, a flame retardant, a curing catalyst, a filler and the like can be added to the resin composition. As the flame retardant, for example, brominated compounds such as tetrabromobisphenol A, phosphorus-containing compounds such as triphenyl phosphate, and inorganic substances such as antimony can be used.As the curing catalyst, for example, imidazoles, Amines such as triethylamine can be used. Further, it is preferable to mix a suitable solvent with the resin composition and use it as a resin varnish. As the solvent, for example, ketones such as methyl ethyl ketone and acetone, alcohols such as methanol and ethanol, water and the like can be used alone or in combination.

In producing the prepreg by impregnating the base material with the resin composition, the base material is
Primary impregnation using a resin composition that is different from the above resin composition and has a good impregnation property to the substrate,
Next, it is preferable to manufacture a prepreg by secondary impregnation using the above resin composition in order to obtain a laminate having good electric characteristics. This is because it is effective to increase the resin content in the prepreg in order to obtain a laminate with good electrical properties, but the tung oil-modified novolak-type phenol formaldehyde resin contains a tung oil component and therefore impregnates the base material. This is because when the resin composition having good impregnating property is used in the primary impregnation, a prepreg having a high resin content can be easily produced. As the resin composition for the primary impregnation, for example, a resin composition containing a resol-type or novolak-type phenol resin diluted with a solvent (including water) can be used.

The electric laminate of the present invention is manufactured by laminating a plurality of the prepregs obtained as described above, further laminating metal foils such as copper, aluminum, nickel and the like, if necessary, and forming the laminate under heat and pressure. . In the present invention, since the resin composition impregnated into the base material contains a formaldehyde condensed resin containing a tung oil-modified novolak type phenol formaldehyde resin and an epoxy resin containing a dicyclopentadiene phenol type epoxy resin, In comparison with the case of using a resin composition comprising a tung oil-modified resol-type phenolic resin, the dehydration-condensation reaction during hot press molding is suppressed,
Therefore, curing shrinkage of the resin is reduced. Therefore, the electrical laminate of the present invention is an electrical laminate having improved warpage and dimensional stability. In addition, a laminate having good water resistance is obtained by containing the dicyclopentadiene phenol type epoxy resin.

When a novolak type epoxy resin is contained together with a dicyclopentadiene phenol type epoxy resin as the epoxy resin, the crosslinked density of the cured resin is improved, so that an electric laminate having improved solder heat resistance is obtained.

When the epoxy resin contains a bisphenol A type epoxy resin together with a dicyclopentadiene phenol type epoxy resin and a novolak type epoxy resin, an electric laminate having less warpage can be obtained.

When brominated bisphenol A type epoxy resin is contained, tetrabromobisphenol A
Thus, it is possible to reduce the amount of a flame retardant composed of a brominated compound which has been conventionally used, and accordingly, it is possible to obtain an electric laminate having improved heat resistance.

[0024]

Next, examples of the present invention and comparative examples will be described.

Example 1 Preparation of Resin Composition for Primary Impregnation 100 parts by weight (hereinafter simply referred to as “parts”) of phenol and 70 parts of formalin having a concentration of 37% by weight (hereinafter simply referred to as “%”) were reacted to form a resol type resin. A phenol reaction product A was obtained. On the other hand, 100 parts of melamine and 37% formalin 100
The parts were reacted to obtain a melamine reaction product B. A mixture of 50 parts of the resol-type phenol reaction product A and 50 parts of the melamine reaction product B was diluted with a mixture of water and methanol to obtain a resin composition for primary impregnation with a solid content of 15%.

Preparation of Resin Composition for Secondary Impregnation Formaldehyde was added to a tung oil phenol reactant obtained by reacting 100 parts of phenol and 80 parts of tung oil, and a novolak reaction was carried out in the presence of an acid catalyst. After dehydration, a tung oil-modified novolak phenol formaldehyde resin was obtained. The obtained tung oil-modified novolak type phenol formaldehyde resin is 45 parts in solid content, and a dicyclopentadiene phenol type epoxy resin (a product of Dainippon Ink and Chemicals, product number E
XA-3830, a solution of methyl ethyl ketone having a solid content of 80%) in a solid content of 30 parts, and in addition, 15 parts of tetrabromobisphenol A and 10 parts of triphenyl phosphate were mixed and mixed, and methyl ethyl ketone was further used as a solvent. Was added to obtain a resin composition for secondary impregnation.

Preparation of Prepreg A kraft paper having a weight of 120 g / m ² was used as a base material, and the kraft paper was primarily impregnated with the resin composition for the primary impregnation, followed by drying with a dryer at 135 ° C. for 30 seconds. Was obtained in a semi-cured state to obtain a primary prepreg A. The primary prepreg A had a solid content of 15% of the resin composition for primary impregnation. The primary prepreg A was secondarily impregnated with the resin composition for secondary impregnation, and dried with a dryer at 155 ° C. for 100 seconds to prepare a prepreg B in which the resin was in a semi-cured state. The solid content of the resin composition in the prepreg B was 54%.

Lamination molding Eight prepregs B obtained as described above are laminated, and a copper foil having a thickness of 0.035 mm is disposed on the uppermost layer and the lowermost layer via an adhesive.
This was molded at a pressure of 100 kg / cm ^{2 at} a temperature of 170 ° C. for 60 minutes, and the resin was cured to obtain a double-sided copper-clad laminate having a thickness of 1.6 mm.

(Example 2) With respect to the composition of the resin composition for secondary impregnation of Example 1, the composition of the solid content of the tung oil-modified novolak type phenol formaldehyde resin was kept at 45 parts, and the dicyclopentadiene phenol type epoxy resin was used. Except that the solid content was changed from 30 parts to 15 parts and the cresol novolak type epoxy resin was newly mixed at 15 parts by solid content, and the mixing amounts of tetrabromobisphenol A and triphenyl phosphate were not changed. In the same manner as in Example 1, a double-sided copper-clad laminate having a thickness of 1.6 mm was obtained.

(Example 3) With respect to the composition of the resin composition for secondary impregnation in Example 2, the solid content of the tung oil-modified novolak type phenol formaldehyde resin was kept at 45 parts, and the dicyclopentadiene phenol type epoxy resin was used. The solid content was changed from 15 parts to 10 parts, the cresol novolak type epoxy resin was changed from 15 parts to 10 parts, and a new tetrabromobisphenol A type epoxy resin was mixed at 10 parts by solid content. A thickness of 1.6 was obtained in the same manner as in Example 2 except that the amounts of tetrabromobisphenol A and triphenyl phosphate were not changed.
mm double-sided copper-clad laminate was obtained.

(Example 4) Regarding the composition of the resin composition for secondary impregnation of Example 3, the solid content of tung oil modified novolak type phenol formaldehyde resin (45 parts) and the solid content of dicyclopentadiene phenol type epoxy resin (10 parts) and the cresol novolak type epoxy resin (10 parts) were left unchanged, and the tetrabromobisphenol A type epoxy resin was changed from 10 parts to 5 parts. In addition, the naphthalene type epoxy resin (large) Nippon Ink Chemical Industry Co., Ltd., product number HP-4032) is 5
A 1.6 mm thick double-sided copper-clad laminate was obtained in the same manner as in Example 3, except that the amounts of tetrabromobisphenol A and triphenyl phosphate were not changed. The used naphthalene type epoxy resin (part number HP-4032) is an epoxy resin containing a compound represented by the following chemical formula 2 as a main component.

[0032]

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(Example 5) With respect to the composition of the resin composition for secondary impregnation of Example 1, the solid content of the tung oil-modified novolak type phenol formaldehyde resin was changed from 45 parts to 5 parts.
0 parts, change the solid content of the dicyclopentadiene phenol type epoxy resin from 30 parts to 15 parts,
A newly brominated phenol novolak type epoxy resin (manufactured by Dainippon Ink and Chemicals, Inc., part number EXA-3817,
Example 1 except that 15 parts by weight of a methyl ethyl ketone solution (solid content: 80%) was mixed in solids, the amount of tetrabromobisphenol A was changed from 15 parts to 10 parts, and the amount of triphenyl phosphate was not changed. In the same manner as in Example 1, a double-sided copper-clad laminate having a thickness of 1.6 mm was obtained.

Example 6 The resin composition for secondary impregnation in Example 1 was mixed with a tung oil-modified novolak type phenol formaldehyde resin as the formaldehyde condensation resin and the melamine reaction product B (melamine formaldehyde resin). 1.6 m in thickness in the same manner as in Example 1 except that a total of 45 parts of the solid material was used.
m double-sided copper-clad laminate was obtained. The solid content of the melamine formaldehyde resin was set so that the solid content of the melamine formaldehyde resin was 10% based on 100 parts by weight of the total solid content of the tung oil-modified novolak-type phenol formaldehyde resin and the melamine formaldehyde resin.

Example 7 The content ratio of the solid content of the melamine formaldehyde resin in Example 6 was determined based on the total content of the solid content of the tung oil-modified novolak type phenol formaldehyde resin and the melamine formaldehyde resin being 100 parts by weight. 20% solids
A 1.6 mm-thick copper-clad laminate was obtained in the same manner as in Example 6, except that the above conditions were satisfied.

(Example 8) With respect to the composition of the resin composition for secondary impregnation of Example 1, the solid content of the tung oil-modified novolak type phenol formaldehyde resin was changed from 45 parts to 3 parts.
0 parts, the solid content of dicyclopentadiene phenol type epoxy resin was changed from 30 parts to 45 parts,
A 1.6 mm thick double-sided copper-clad laminate was obtained in the same manner as in Example 1 except that the amounts of tetrabromobisphenol A and triphenyl phosphate were not changed.

Comparative Example 1 A double-sided copper-clad laminate having a thickness of 1.6 mm was obtained in the same manner as in Example 1 except that the resin composition for secondary impregnation was prepared as follows. Phenol 1
After reacting 00 parts, 80 parts of formalin having a concentration of 37% and 80 parts of tung oil, a tung oil-modified resole phenol resin was obtained.
5 parts, dicyclopentadiene phenol type epoxy resin (manufactured by Dainippon Ink and Chemicals, Inc., part number EXA-3830,
30 parts of solid content of methyl ethyl ketone dissolved at 80%) and 15 parts of tetrabromobisphenol A
And 10 parts of triphenyl phosphate, and methyl ethyl ketone was further added as a solvent to obtain a resin composition for secondary impregnation.

(Comparative Example 2) With respect to the composition of the resin composition for secondary impregnation in Example 2, the solid content of the tung oil-modified novolak type phenol formaldehyde resin was kept at 45 parts, and the dicyclopentadiene phenol type epoxy resin was used. And 30 parts of a phenol novolak type epoxy resin in place of the cresol novolak type epoxy resin, and a thickness of 1 in the same manner as in Example 2 except that the amounts of tetrabromobisphenol A and triphenyl phosphate were not changed. A 6 mm double-sided copper-clad laminate was obtained.

The above Examples 1 to 8 and Comparative Examples 1 to
The copper clad laminate obtained in Comparative Example 2 was evaluated for warpage, dimensional change (dimensional stability), solder heat resistance, bending strength, insulation resistance, tracking resistance, and water absorption (water resistance). And Table 2. Tables 1 and 2 also show the compounding amounts of the respective materials for obtaining the resin composition for secondary impregnation.

Evaluation of warpage is 230 mm × 230 m
m after forming a pattern on both sides of the copper-clad laminate,
Heating was performed at 30 ° C. for 30 minutes, the amount of warpage of the four corners was measured, the average value was determined, and this was defined as the amount of warpage.

The evaluation of the dimensional change was obtained by measuring the expansion rate from 30 ° C. to 150 ° C. and the shrinkage rate when cooled to 30 ° C. in the horizontal direction of the test piece from which the copper foil had been removed. In addition, the term "horizontal direction" used herein refers to the vertical direction when the kraft paper as the base material is continuously formed, and the horizontal direction to be perpendicular to the vertical direction.

The evaluation of solder heat resistance was carried out based on JIS-C6481 by floating the solder at 260 ° C. and measuring the time until blistering occurred. Evaluation of insulation resistance is JIS-C6481
And the insulation resistance after the treatment of D-2 / 100 was measured.

With respect to the tracking resistance, an electrode is arranged at a distance of 4 mm from the etched surface of the copper foil, a 0.1% ammonium chloride aqueous solution is dropped at intervals of 30 seconds while applying a voltage, and the laminate is ignited. The number of drops was recorded by changing the applied voltage, and a voltage corresponding to 50 drops was obtained from the result and evaluated. The electrodes used were brass.

The water absorption was measured in accordance with JIS-C6481 based on JIS-C6481. A test piece cut into a square of 5 cm from which the copper foil had been removed was first dried at 50 ° C. for 24 hours as a pretreatment, and the weight was measured to obtain a reference weight. Then, after being immersed in water at 23 ° C. for 24 hours, the weight was measured again to determine the water absorption.

[0045]

[Table 1]

[0046]

[Table 2]

From the results in Tables 1 and 2, the following has become clear. Examples 1 to 8 were superior to Comparative Example 1 using a resin composition containing a tung oil-modified resol-type phenol resin as a main component in all the performances listed here. Examples 1 and 8 were warped, changed in size, and changed in size compared with Comparative Example 2.
Solder heat resistance and water absorption are good, and Examples 2 to 5 are warped, solder heat resistance and water absorption are good as compared with Comparative Example 2,
The other characteristics were also substantially equivalent or equivalent. In Examples 6 and 7 containing a melamine formaldehyde resin, the insulation resistance and the tracking resistance were equal to or higher than those in Example 1.

[0048]

In the invention according to claims 1 to 6, since the resin composition impregnated in the base material contains tung oil-modified novolak type phenol formaldehyde resin and dicyclopentadiene phenol type epoxy resin, it is mainly used. Compared with a resin composition comprising a tung oil-modified resol-type phenol resin, a dehydration-condensation reaction at the time of heat and pressure molding is suppressed, and curing shrinkage of the resin is reduced. Therefore, the electrical laminate of the invention according to claims 1 to 6 is warped and dimensionally stable as compared with an electrical laminate obtained mainly by using a resin composition comprising a tung oil-modified resol-type phenol resin. A laminate having good properties is obtained. In addition, since it contains a dicyclopentadiene phenol type epoxy resin, a laminate having good water resistance can be obtained.

In the electric laminate according to the second aspect of the present invention, since a resin composition containing a melamine formaldehyde resin is used, a laminate having good insulation resistance and tracking resistance in addition to the above effects can be obtained.

Claims (6)

[Claims] 1. An electric laminate obtained by laminating a prepreg obtained by impregnating a base material with a resin composition and molding by heating and pressing, wherein the resin composition comprises a tung oil-modified novolak-type phenol formaldehyde resin. An electric laminate comprising a formaldehyde condensed resin and an epoxy resin containing a dicyclopentadiene phenol type epoxy resin. 2. The electrical laminate according to claim 1, further comprising a melamine formaldehyde resin as the formaldehyde condensation resin. 3. The solid content of the melamine formaldehyde resin is 5 to 20 parts by weight based on a total of 100 parts by weight of the solid content of the tung oil-modified novolak type phenol formaldehyde resin and the melamine formaldehyde resin. Electrical laminates. 4. The method according to claim 1, further comprising a novolak type epoxy resin as the epoxy resin.
The laminate for electricity according to any one of the above. 5. The electric laminate according to claim 4, further comprising a bisphenol A type epoxy resin as the epoxy resin. 6. The electric laminate according to claim 5, further comprising a naphthalene type epoxy resin as the epoxy resin.