JPH1135659A - Resin composition, prepreg and printed wiring base board and production of these - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition, for a sealer and an insulation layer of a printed wiring base board having low hygroscopicity and low permittivity, which is required along with progress of the mounting technique such as packaging of semiconductor and COB. SOLUTION: The resin composition for electric insulation is obtained by including (A) a naphthol-modified glycidyl ether-type or biphenyl group- containing glycidyl ether-type epoxy resin and (B) a curing agent having the same chemical structure as the resin except that the glycidyl ether group of the resin is replaced for hydroxyl group. The prepreg is obtained by impregnating in a substrate a thermosetting resin composition containing a glycidyl ether- type epoxy resin and a curing agent having the same chemical structure as the resin except that the glycidyl ether group of the resin is replaced for hydroxyl group, followed by drying. The thermosetting resin composition is used as an insulation layer for printed wiring base board.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition, a prepreg, a printed wiring board and a method for producing the same.
More specifically, a thermosetting resin composition for electrical insulation used for a semiconductor encapsulant and an insulating layer of a printed wiring board, a prepreg used as a material for forming an insulating layer of a printed wiring board, and a print used for various electronic devices The present invention relates to a wiring board and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, electronic devices have been reduced in size and weight as well as digitalized electronic circuits for higher functionality.
Higher speed is required, and semiconductors and printed wiring boards to be mounted on these electronic devices are also required to have higher densities. Therefore, in the development of new electronic equipment,
Development of these semiconductors and printed wiring boards themselves,
Improvement of those mounting technologies is also an important factor.

[0003] As is well known, semiconductors are becoming more and more narrow-pitch and multi-pin due to higher integration and higher functionality. It has become difficult to answer. Therefore,
Chip-size package (CSP) or chip-on-board (C)
The development of a packaging technology such as OB) is under study. On the other hand, in view of the above situation, printed wiring boards are also required to have higher performance and higher density, as well as smaller size and lighter weight. Therefore, development of a new packaging technology including a printed wiring board technology is an important point in realizing further downsizing and weight reduction and higher functionality of electronic devices in the future.

In general, when a semiconductor chip package or a chip component is surface-mounted, an epoxy resin is used as a sealant for protecting the semiconductor chip from an external environment. One of the problems with the sealant is cracking, and the main cause of cracking is moisture absorption of the epoxy resin. In addition, the moisture absorption of the epoxy resin causes corrosion and migration of component electrodes, and also affects an increase in dielectric constant and dielectric loss. Therefore, among the physical properties of the epoxy resin required for the sealing agent, low moisture absorption is the most important. Conventionally, a phenol novolak type or cresol novolak type low hygroscopic epoxy resin has been used as an epoxy resin for a sealant. Also, amine compounds having high hygroscopicity are not used as curing agents, but acid anhydrides and phenol novolaks are used, and low-water-absorbing epoxy resins and curing agents are being actively developed at present. .

[0005] The insulating layer of the printed wiring board is also a composite molded article of an epoxy resin and a glass woven fabric or an aramid nonwoven fabric, but the epoxy resin used is not required to have low moisture at the level of a sealant. Rather, development for improving heat resistance is being pursued. However, considering the realization of the COB and the fact that the substrate is adopted for a high-frequency circuit in the future, it is considered that moisture absorption is always the most important problem in a printed wiring board. In particular, changes in the dielectric constant and dielectric loss due to moisture absorption restrict the mounting of a high-speed chip and the design of a high-frequency circuit. Therefore, it is important to develop a printed wiring board on the premise of moisture absorption resistance, and it is expected that the same level of moisture absorption as that required for a sealing agent will be required.

[0006]

As described above, the development of low moisture absorption of the epoxy resin and the curing agent used for the encapsulant has been developed individually, and the moisture absorption of the epoxy resin and the curing agent itself is considerably small. Has become. However, epoxy resins and curing agents with low hygroscopicity are expensive, and studies on the effective combination of epoxy resin and curing agent in consideration of the structure of the cured epoxy resin are not sufficient, so they are excellent alone. It seems that their low hygroscopicity is not sufficiently exhibited by the cured product.

On the other hand, the epoxy resin and the curing agent used for the printed wiring board are not sufficiently reduced in moisture absorption. The reason is that a glass base material having almost no hygroscopicity is generally used as the base material, and the requirement of the insulating layer resin to reduce the hygroscopicity is not as high as that of the sealing agent. However, if the development of COB and the like is promoted in the future, it is certain that resins and fibers with low dielectric constant and low dielectric loss will be used for the base material. Will increase to the level.

[0008]

Means for Solving the Problems In order to solve the above-mentioned problems, first, the present invention provides at least one resin selected from the group consisting of a naphthol-modified glycidyl ether type epoxy resin and a glycidyl ether type epoxy resin containing a biphenyl group. The present invention provides a thermosetting resin composition comprising: a kind of epoxy resin; and a curing agent having the same chemical structure except that the glycidyl ether group of the epoxy resin is replaced by a hydroxyl group. When such a combination of the epoxy resin and the curing agent is used, the chemical structure of the epoxy resin cured product becomes homogeneous, and the residual ratio of the hygroscopic unreacted hydroxyl groups decreases, so that the epoxy resin has excellent low hygroscopicity and dielectric properties. Thus, a resin composition useful for electrical insulation can be obtained.

Secondly, the present invention provides a curing agent having the same chemical structure except that a base material, a glycidyl ether type epoxy resin impregnated in the base material, and a glycidyl ether group of the epoxy resin are substituted with a hydroxyl group. A prepreg comprising a thermosetting resin composition comprising: When using such a combination of an epoxy resin and a curing agent,
Since the chemical structure of the cured epoxy resin becomes homogeneous and the residual ratio of unreacted hydroxyl groups of hygroscopicity decreases, a prepreg having excellent low hygroscopicity and dielectric properties can be obtained.

Third, the present invention provides at least one insulating layer formed from a thermosetting resin composition or a substrate impregnated with the resin composition, and at least one insulating layer formed on the surface of the insulating layer. A printed circuit board having a circuit pattern, wherein the resin composition is a glycidyl ether type epoxy resin, and a curing agent having the same chemical structure except that the glycidyl ether group of the epoxy resin is replaced with a hydroxyl group. And a printed wiring board comprising: When such a combination of the epoxy resin and the curing agent is used, the chemical structure of the epoxy resin cured product becomes homogeneous, and the residual ratio of the hygroscopic unreacted hydroxyl groups decreases, so that the epoxy resin has excellent low hygroscopicity and dielectric properties. A printed wiring board is obtained.

[0011] Fourth, the present invention provides a thermosetting resin comprising, as a base material, a glycidyl ether type epoxy resin and a curing agent having the same chemical structure except that the glycidyl ether group of the epoxy resin is replaced with a hydroxyl group. Impregnated with a composition, dried, and then, the substrate impregnated with the resin composition, impregnated with a resin composition different from the resin composition,
A method for producing a printed wiring board, comprising: a step of drying to form a prepreg; a step of thermocompression bonding a metal foil to at least one surface of the prepreg; and a step of forming a circuit pattern. According to this manufacturing method, the base material can be covered with the low-hygroscopic epoxy resin cured body,
Water can be prevented from intervening at the interface between the base material and the resin, and a wiring board having excellent low moisture absorption and dielectric properties can be manufactured.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The thermosetting resin composition of the present invention comprises
At least one epoxy resin selected from the group consisting of a naphthol-modified glycidyl ether type epoxy resin and a glycidyl ether type epoxy resin containing a biphenyl group, and the same chemical structure except that the glycidyl ether group of the epoxy resin is substituted with a hydroxyl group. And a curing agent having the formula: The amount of the curing agent is as follows.
50 to 80 parts by weight, preferably 60 parts by weight, per 100 parts by weight
７５75 parts by weight. When a curing agent is used in such an amount, sufficient curing performance can be obtained.

The naphthol-modified glycidyl ether type epoxy resin is a resin in which a naphthalene skeleton is introduced into the resin to increase the epoxy equivalent, and reduces the proportion of a hydrophilic group such as an ether group or a hydroxyl group contained in the cured product. Low moisture absorption epoxy resin. Further, since the curing agent has the same chemical structure except that the glycidyl ether group of this epoxy resin is substituted with a hydroxyl group, the ratio of the hydrophilic group is small and the curing agent has low hygroscopicity.

Thus, by making the skeleton of the epoxy resin and the skeleton of the curing agent the same structure, the epoxy group and the hydroxyl group react efficiently, and the residual ratio of the hygroscopic unreacted hydroxyl group in the cured product is reduced. be able to. Therefore, it is possible to provide a resin composition which has a lower hygroscopic property and gives a cured body having excellent dielectric properties as compared with the case where each is used alone. Further, when the epoxy resin and the curing agent are used, the number of reaction points between the epoxy group and the hydroxyl group, that is, the number of crosslinking points is reduced, so that the crosslinking density of the cured product is reduced. As a result, the cured body becomes flexible and the adhesiveness is improved. Note that a brominated naphthol-modified glycidyl ether type epoxy resin and a curing agent having the same chemical structure may be combined except that the glycidyl ether group of the brominated epoxy resin is substituted with a hydroxyl group, and the same as described above. And the flame retardancy can be imparted.

The glycidyl ether type epoxy resin containing a biphenyl group is a resin in which a biphenyl skeleton is introduced into an epoxy resin to increase the epoxy equivalent, and like the naphthol-modified glycidyl ether type epoxy resin, it is a low hygroscopic epoxy resin. is there. Furthermore, in this resin, the free rotation of the benzene ring in the biphenyl skeleton is restricted by steric hindrance, and a cured body in which molecules are packed is easily formed. Therefore, a cured product having a structure that does not easily transmit water is provided.

A curing agent having the same chemical structure except that the glycidyl ether group of the glycidyl ether type epoxy resin containing a biphenyl group is substituted with a hydroxyl group also exhibits the above-mentioned effects, and therefore has low hygroscopicity. Therefore, by using the same structure of the skeleton of these epoxy resins and the skeleton of the curing agent, the same effects as in the case of the naphthol-modified glycidyl ether type epoxy resin described above can be obtained,
It is possible to provide a resin composition which has a lower hygroscopicity and gives a cured body having excellent dielectric properties as compared with the case where each is used alone. The adhesiveness is also improved as in the case of the naphthol-modified glycidyl ether type epoxy resin. Incidentally, a brominated product of a glycidyl ether type epoxy resin containing a biphenyl group and a brominated product of a curing agent having the same chemical structure except that the glycidyl ether group of the epoxy resin is substituted with a hydroxyl group may be used,
The same effect as described above can be obtained, and flame retardancy can be imparted.

Further, the prepreg of the present invention provides a thermosetting resin comprising, as a base material, a glycidyl ether type epoxy resin and a curing agent having the same chemical structure except that the glycidyl ether group of the epoxy resin is replaced by a hydroxyl group. A prepreg impregnated with the composition and dried. As already described, by having the same structure of the skeleton of the epoxy resin and the skeleton of the curing agent, the epoxy group and the hydroxyl group react efficiently, and the residual rate of the hygroscopic unreacted hydroxyl group in the cured product is reduced. Can be. Therefore, the prepreg of the present invention has a small amount of moisture absorption and is excellent in dielectric properties.

In order to reduce the cost, it is preferable to use a general-purpose epoxy resin as the glycidyl ether type epoxy resin. For example, the glycidyl ether type epoxy resin may be bisphenol A diglycidyl ether,
It is preferably at least one selected from the group consisting of bisphenol F diglycidyl ether, tetrabromobisphenol A diglycidyl ether, phenol novolak glycidyl ether, and cresol novolac glycidyl ether. When importance is placed on the low hygroscopicity of the prepreg from the viewpoint of cost, it is preferable to use at least one of a naphthol-modified glycidyl ether type epoxy resin and a biphenyl novolac glycidyl ether type epoxy resin as the epoxy resin.

As the substrate, a conventionally used substrate can be used, and is preferably selected from the group consisting of glass woven fabric, glass nonwoven fabric, wholly aromatic polyester nonwoven fabric, aramid woven fabric and aramid nonwoven fabric. . The conditions for impregnation and drying of the base material with the resin and the amount of the resin impregnation may be the same as those of the conventional prepreg.

The printed wiring board of the present invention has at least one insulating layer formed from a thermosetting resin composition or a base material impregnated with the resin composition, and a surface of at least one of the insulating layers. Having a formed circuit pattern,
The resin composition comprises a glycidyl ether type epoxy resin and a curing agent having the same chemical structure except that the glycidyl ether group of the epoxy resin is substituted with a hydroxyl group.

As described above, when the skeleton of the epoxy resin and the skeleton of the curing agent have the same structure, the epoxy groups and the hydroxyl groups react efficiently, and the residual ratio of the hygroscopic unreacted hydroxyl groups in the cured product is reduced. Can be reduced. Therefore, the printed wiring board of the present invention has a small amount of moisture absorption and is excellent in dielectric properties.

In order to reduce the cost, it is preferable to use a general-purpose epoxy resin as the glycidyl ether type epoxy resin. For example, when the glycidyl ether type epoxy resin is bisphenol A diglycidyl ether,
It is preferably at least one selected from the group consisting of bisphenol F diglycidyl ether, tetrabromobisphenol A diglycidyl ether, phenol novolak glycidyl ether, and cresol novolac glycidyl ether.

When importance is placed on low moisture absorption of the printed wiring board from the viewpoint of cost, it is preferable to use at least one of a naphthol-modified glycidyl ether type epoxy resin and a biphenyl novolac glycidyl ether type epoxy resin as the epoxy resin. When these epoxy resins are used, the adhesiveness of the resin is improved as described above, so that the adhesiveness between the metal and the base material is also improved.

As a base material for producing a printed wiring board, a conventionally used base material can be used.
Preferably, it is selected from the group consisting of glass woven fabric, glass nonwoven fabric, wholly aromatic polyester nonwoven fabric, aramid woven fabric, and aramid nonwoven fabric. The conditions for impregnation and drying of the base material with the resin and the amount of the resin impregnation may be the same as those of the conventional printed wiring base material. The circuit pattern is usually
It is formed by metal foil or metal plating, but may be formed from a conductive paste. The metal forming the circuit pattern is preferably at least one selected from the group consisting of copper, gold, silver, nickel and solder. The circuit pattern can be formed in the same manner as in the case of a conventional printed wiring board.

Further, the printed wiring board of the present invention preferably has the same chemical structure as the following except that the base material is a glycidyl ether type epoxy resin and the glycidyl ether group of the epoxy resin is replaced by a hydroxyl group. Impregnated with a thermosetting resin composition containing a curing agent, dried,
Next, a step of impregnating the base material impregnated with the resin composition with a resin composition different from the resin composition and drying to form a prepreg, and thermocompression bonding a metal foil to at least one surface of the prepreg. And a step of forming a circuit pattern.

As described above, since the skeleton of the epoxy resin and the skeleton of the curing agent have the same structure, the epoxy groups and the hydroxyl groups react efficiently, and the residual rate of the hygroscopic unreacted hydroxyl groups in the cured product is reduced. Can be done. According to this manufacturing method, the surface of the base material can be covered with the cured epoxy resin having low moisture absorption and excellent dielectric properties, so that water molecules hardly intervene at the interface between the base material and the resin.
As a result, a printed wiring board having low hygroscopicity and excellent dielectric properties can be manufactured.

In the step of preparing the prepreg,
The first resin impregnation amount is preferably 5% by weight or more based on the weight of the substrate. The first resin impregnation amount is 5% by weight
If the amount is less, the resin cannot effectively cover the substrate surface.

Other than the above impregnation amount, the conditions in each of the above steps may be the same as those in the case of the conventional method for manufacturing a printed wiring board. The resin composition used in the second impregnation step may be any resin composition as long as it is different from the resin composition used in the first impregnation step, and is preferably an epoxy resin composition. The impregnation amount of the resin composition in the second impregnation step is generally 50 to 50% based on the total weight of the prepreg.
60% by weight. The second impregnation may be repeated a plurality of times until a predetermined impregnation amount is reached.

In order to reduce the cost, it is preferable to use a general-purpose epoxy resin as the glycidyl ether type epoxy resin. For example, the glycidyl ether type epoxy resin may be bisphenol A diglycidyl ether,
It is preferably at least one selected from the group consisting of bisphenol F diglycidyl ether, tetrabromobisphenol A diglycidyl ether, phenol novolak glycidyl ether, and cresol novolac glycidyl ether.

When importance is placed on low moisture absorption of the printed wiring board from the viewpoint of cost, it is preferable to use at least one of a naphthol-modified glycidyl ether type epoxy resin and a biphenyl novolak glycidyl ether type epoxy resin as the epoxy resin. When these epoxy resins are used, the adhesiveness of the resin is improved as described above, so that the adhesiveness between the metal and the base material is also improved.

As a base material for producing a printed wiring board, a conventionally used base material can be used.
Preferably, it is selected from the group consisting of glass woven fabric, glass nonwoven fabric, wholly aromatic polyester nonwoven fabric, aramid woven fabric, and aramid nonwoven fabric. The metal foil is preferably a commonly used copper foil.

[0032]

The present invention will now be described more specifically with reference to examples and comparative examples. Note that the present invention is not limited by these examples. In Examples and Comparative Examples,% and parts are by weight unless otherwise specified.

Comparative Example 1 A resin corresponding to FR5 having the following composition was dissolved in methyl ethyl ketone (MEK) to prepare a 60% by weight resin solution. This resin solution was spread on an aluminum vat and dried at room temperature in a vacuum for 1 hour. Further, after the aluminum bat containing the resin composition was cured at 140 ° C. to the B stage, the resin composition was crushed and put into a mold, and cured by a vacuum hot press to prepare a resin plate. The conditions of the vacuum hot pressing were as follows: pressure 50 kg / cm ² , temperature 200 ° C., 1 hour.

Resin composition equivalent to FR5: brominated bisphenol A type epoxy resin 35.0 parts (bromine content: 23%, epoxy equivalent: 270) trifunctional epoxy resin 35.0 parts (bromine content: 23%, epoxy equivalent: 270) Phenol novolak curing agent 30.0 parts (hydroxyl equivalent: 120) triphenylphosphine 1.0 part

Comparative Example 2 Formula (I):

Embedded image (In the formula, G represents a glycidyl group, and n represents a number of 0 to 4.)
A naphthol-modified glycidyl ether type epoxy resin and a phenol novolak curing agent are dissolved in MEK at an equivalent ratio (total of 100 parts), and 1 part of triphenylphosphine is further dissolved as a curing accelerator in the above solution. A resin plate was prepared in the same procedure as in Comparative Example 1, except that the concentration was adjusted to be 60% by weight.

Comparative Example 3 Formula (II):

Embedded image (Wherein G and n have the same meanings as described above). A biphenyl novolak glycidyl ether type epoxy resin and a phenol novolak curing agent are dissolved in MEK in an equivalent ratio (total of 100 parts), and the curing is further accelerated. A resin plate was prepared in the same procedure as in Comparative Example 1, except that 1 part of triphenylphosphine was dissolved in the solution as an agent and the concentration of the resin solution was adjusted to 60%.

Comparative Example 4 The same naphthol-modified glycidyl ether type epoxy resin used in Comparative Example 2) and a compound of the formula (III):

Embedded image (Wherein G and n have the same meanings as described above) and a phenol biphenyl novolak curing agent represented by the following formula (E) (100 parts in total) was dissolved in MEK, and 1 part of triphenylphosphine was used as a curing accelerator. Was dissolved in the above solution, and a resin plate was prepared in the same procedure as in Comparative Example 1, except that the concentration of the resin solution was adjusted to 60% by weight.

Examples 1-1 and 1-2 Formula (II) (Example 1-1) or Formula (III) (Example 1)
The glycidyl ether type epoxy resin shown in 2) and a curing agent having the same chemical structure except that the glycidyl ether group of the epoxy resin is replaced with a hydroxyl group are dissolved in MEK in an equivalent ratio (100 parts in total), and further dissolved in MEK. A resin plate was prepared in the same procedure as in Comparative Example 1, except that 1 part of triphenylphosphine was dissolved in the solution as a curing accelerator. Each of the resin plates produced in Comparative Examples 1 to 4 and Example 1 was measured at a temperature of 60 ° C. and a humidity of 95% RH for 300 hours to measure the moisture absorption and the dielectric constant.

The moisture absorption and the dielectric constant were measured by the following methods. After drying the moisture absorption resin plate at 120 ° C. for 2 to 3 hours, its initial weight was measured. Next, this resin plate was heated at 60 ° C. and 95% RH.
Was taken out after a predetermined time, and its weight was measured. The moisture absorption was determined from the difference between this weight and the initial weight. After the dielectric resin plate was dried at 120 ° C. for 2 to 3 hours, the dielectric constant was measured by a cavity resonance method. As a measuring device, a microwave molecular orientation meter manufactured by Oji Paper Co., Ltd. was used. Next, the resin plate was placed in an environmental bath at 60 ° C. and 95% RH, taken out after a predetermined time, measured for its dielectric constant, and the ε change rate was determined from the measured dielectric constant. Table 1 shows the results.

[0040]

[Table 1]

Comparative Example 5 Aramid nonwoven fabric (Technola manufactured by Teijin Limited) was impregnated with the same 60% by weight resin solution as prepared in Comparative Example 1, and dried at 140 ° C. to prepare a prepreg. In addition,
The resin impregnation amount was 50% based on the total weight of the prepreg.

Comparative Example 6 An aramid nonwoven fabric (Technola manufactured by Teijin Limited) was impregnated with the same 60% by weight resin solution as prepared in Comparative Example 2, and dried at 140 ° C. to prepare a prepreg. In addition,
The resin impregnation amount was 50% based on the total weight of the prepreg.

Comparative Example 7 The same 60% by weight resin solution as prepared in Comparative Example 3 was impregnated into an aramid nonwoven fabric (Technola manufactured by Teijin Limited) and dried at 140 ° C. to prepare a prepreg. In addition,
The resin impregnation amount is 50% by weight based on the total weight of the prepreg.
And

Comparative Example 8 The same 60% by weight resin solution as prepared in Comparative Example 4 was impregnated into an aramid nonwoven fabric (Technola manufactured by Teijin Limited) and dried at 140 ° C. to prepare a prepreg. In addition,
The resin impregnation amount is 50% by weight based on the total weight of the prepreg.
And

Example 2 A 60% by weight resin solution prepared by the same procedure as in Example 1 was impregnated into an aramid nonwoven fabric (Technola manufactured by Teijin Limited) and dried at 140 ° C. to prepare a prepreg. In addition,
Examples of the epoxy resin include an epoxy resin represented by the formula (I) (Example 2-1), an epoxy resin represented by the formula (II) (Example 2-2), and a phenol novolak type epoxy resin (Example 2-3). ), A cresol novolak type epoxy resin (Example 2-4), a bisphenol A type epoxy resin (Example 2-5) and a bisphenol F type epoxy resin (Example 2-6). Prepare a resin solution comprising a curing agent, respectively,
The resin impregnation amount was 50% based on the total weight of the prepreg. Each of the prepregs manufactured in Comparative Examples 5 to 8 and Example 2 was measured for the moisture absorption and the dielectric constant when held at 60 ° C. and 95% RH for 300 hours in the same manner as described above. Table 2 shows the results. When another aramid nonwoven fabric (DuPont thermomount) was used as the substrate, the same results as those shown in Table 2 were obtained.

[0046]

[Table 2]

Comparative Example 9 A polyethylene terephthalate (PET) film was laminated on both sides of a prepreg prepared in the same procedure as in Comparative Example 5. Next, a predetermined portion of the prepreg was processed with a via using a carbon dioxide gas laser, and the via was filled with a conductive paste. The conductive paste used here consisted of copper powder (85%) having an average particle size of 2 μm as a conductive substance and solventless epoxy resin (remainder) as a binder resin, and three pieces of copper powder and binder resin were used. It is prepared by kneading with a roll. After peeling PET from both sides of the prepreg filled with the conductive paste, sandwich the prepreg with copper foil,
After heating and pressurizing with a vacuum hot press at 200 ° C. and 55 kg / cm ² for 1 hour, an inner layer circuit pattern was formed by etching to form a double-sided board. A prepreg filled with conductive paste in vias created in the same way as above,
A copper foil is laminated on both surfaces of the double-sided board and copper foil is further laminated on the outer surfaces of both prepregs. After thermocompression bonding under the same conditions as above, a circuit pattern for an outer layer is formed by etching to obtain a printed wiring board having a four-layer structure. Was. Note that a printed wiring board having an arbitrary number of layers can be obtained by repeating the above series of steps.

Comparative Example 10 A printed wiring board having a four-layer structure was prepared in the same manner as in Comparative Example 9 except that a prepreg prepared in the same procedure as in Comparative Example 6 was used. Comparative Example 11 A printed wiring board having a four-layer structure was prepared in the same manner as in Comparative Example 9 except that a prepreg prepared in the same procedure as in Comparative Example 7 was used. Comparative Example 12 A printed wiring board having a four-layer structure was prepared in the same manner as in Comparative Example 9, except that a prepreg prepared in the same procedure as in Comparative Example 8 was used.

Example 3 Various printed wiring boards having a four-layer structure were prepared in the same manner as in Comparative Example 9 except that each prepreg prepared in the same procedure as in Example 2 was used.

Each of the printed wiring boards having a four-layer structure manufactured in Comparative Examples 9 to 12 and Example 4 was heated at 60.degree.
The moisture absorption and the dielectric constant when held at% RH for 300 hours were measured in the same manner as described above. Table 3 shows the results. When another aramid nonwoven fabric (DuPont thermomount) was used as the substrate, the same results as those shown in Table 3 were obtained.

[0051]

[Table 3]

Comparative Example 13 Aramid nonwoven fabric (Technola manufactured by Teijin Limited) was impregnated with a 30% resin solution prepared in the same procedure as in Comparative Example 1, and
The nonwoven fabric was dried at 140 ° C. and further impregnated with the 40% resin solution prepared in the same procedure as in Comparative Example 1, and dried at 140 ° C. to prepare a prepreg. The first resin impregnation amount was 25% based on the weight of the base material, and the total resin impregnation amount of the first and second times was 50% based on the total weight of the prepreg.
And A printed wiring board having a four-layer structure was prepared in the same manner as in Comparative Example 9 except that the prepreg prepared in this manner was used.

Comparative Example 14 An aramid nonwoven fabric (Technola manufactured by Teijin Limited) was impregnated with a 30% resin solution prepared according to the same procedure as in Comparative Example 2.
The nonwoven fabric was dried at 140 ° C. and further impregnated with the 40% resin solution prepared in the same procedure as in Comparative Example 1, and dried at 140 ° C. to prepare a prepreg. The first resin impregnation amount was 25% based on the weight of the base material, and the total resin impregnation amount of the first and second times was 50% based on the total weight of the prepreg.
And A printed wiring board having a four-layer structure was prepared in the same manner as in Comparative Example 9 except that the prepreg prepared in this manner was used.

Comparative Example 15 A 30% resin solution prepared in the same procedure as in Comparative Example 3 was impregnated into an aramid nonwoven fabric (Technola manufactured by Teijin Limited).
The nonwoven fabric was dried at 140 ° C. and further impregnated with the 40% resin solution prepared in the same procedure as in Comparative Example 1, and dried at 140 ° C. to prepare a prepreg. The first resin impregnation amount was 25% based on the weight of the base material, and the total resin impregnation amount of the first and second times was 50% based on the total weight of the prepreg.
And A printed wiring board having a four-layer structure was prepared in the same manner as in Comparative Example 9 except that the prepreg prepared in this manner was used.

Comparative Example 16 An aramid nonwoven fabric (Technola manufactured by Teijin Limited) was impregnated with a 30% resin solution prepared in the same procedure as in Comparative Example 4.
The nonwoven fabric was dried at 140 ° C. and further impregnated with the 40% resin solution prepared in the same procedure as in Comparative Example 1, and dried at 140 ° C. to prepare a prepreg. The first resin impregnation amount was 25% based on the weight of the base material, and the total resin impregnation amount of the first and second times was 50% based on the total weight of the prepreg.
And A printed wiring board having a four-layer structure was prepared in the same manner as in Comparative Example 9 except that the prepreg prepared in this manner was used.

Comparative Example 17 A 3% resin solution containing an epoxy resin represented by the formula (I) and a curing agent corresponding thereto in an equivalent ratio was prepared and impregnated into an aramid nonwoven fabric (Technola manufactured by Teijin Limited).
5 dried at 0 ° C. and further prepared in the same procedure as Comparative Example 1.
The nonwoven fabric was impregnated with a 0% resin solution and dried at 140 ° C. to prepare a prepreg. The first resin impregnation amount was 3% based on the weight of the base material, and the total resin impregnation amount for the first and second times was 50% based on the total weight of the prepreg. Various printed wiring boards having a four-layer structure were prepared in the same manner as in Comparative Example 9 except that the prepreg thus prepared was used.

Example 4 A 5 or 15% resin solution containing an epoxy resin represented by the formula (I) and a curing agent corresponding thereto in an equivalent ratio was prepared.
Aramid nonwoven fabric (Technola manufactured by Teijin Limited)
After drying at 140 ° C., the nonwoven fabric was impregnated with a 50% resin solution prepared by the same procedure as in Comparative Example 1, and dried at 140 ° C. to prepare each prepreg. The first resin impregnation amount was 5 or 15% with respect to the substrate weight, and the first and second resin impregnation amounts were 50% with respect to the total weight of the prepreg. Various printed wiring boards having a four-layer structure were prepared in the same manner as in Comparative Example 9 except that each prepreg prepared in this manner was used.

Example 5 An epoxy resin represented by the formula (I) (Example 5-1), an epoxy resin represented by the formula (II) (Example 5-2), and a phenol novolak type epoxy resin (Example 5) 3), cresol novolak type epoxy resin (Example 5-4),
A 30% resin solution containing a bisphenol A type epoxy resin (Example 5-5) and a bisphenol F type epoxy resin (Example 5-6) and a corresponding curing agent at an equivalent ratio are each aramid nonwoven fabric (Teijin Co., Ltd.) After impregnating the nonwoven fabric, the nonwoven fabric was impregnated with a 40% resin solution prepared in the same procedure as in Comparative Example 1 and dried at 140 ° C to prepare a prepreg.
The first resin impregnation amount was 25% based on the substrate weight.
The total resin impregnation amount in the first and second times was 50% based on the total weight of the prepreg. Various printed wiring boards having a four-layer structure were prepared in the same manner as in Comparative Example 9 except that each prepreg prepared in this manner was used.

Each of the four-layer printed wiring boards manufactured in Comparative Examples 13 to 17 and Examples 4 and 5 was
The moisture absorption and the dielectric constant when kept at 95 ° C. and 95% RH for 300 hours were measured in the same manner as described above. Table 4 shows the results. In addition, when another aramid nonwoven fabric (DuPont Thermomount) was used as the substrate, the same results as those shown in Table 4 were obtained.

[0060]

[Table 4]

Examples 1-4 and Comparative Examples 1-17
Consider the results shown in Tables 1 to 4 obtained for. From the results shown in Table 1, Comparative Example 1 using a resin equivalent to FR5
Comparative Examples 2 to 4 using low hygroscopic epoxy resin
It can be seen that the moisture absorption of the sample was small. This is because the properties of the epoxy resin itself appeared due to the use of the low-hygroscopic epoxy resin. On the other hand, as shown in Example 1, when these low hygroscopic epoxy resins are used and the epoxy resin and the curing agent have the same skeleton, the moisture absorption rate is further reduced. This is because the distance between the epoxy groups of the epoxy resin and the distance between the hydroxyl groups of the curing agent are almost the same, so that the epoxy groups and the hydroxyl groups react efficiently, and as a result, the unreacted hydrophilic groups in the cured product are not obtained. This is because the residual ratio of the reactive hydroxyl group decreases, and the moisture absorption of the cured product decreases.
In addition, corresponding to these moisture absorption rates, the same tendency as the moisture absorption rate was obtained for the magnitude of the dielectric constant ε. According to the study of the inventors, it has been confirmed that the relationship between the moisture absorption and the dielectric constant is in a linear system, and is not related to the type of the cured body. Therefore, it can be said that a cured epoxy resin having a low moisture absorption is also excellent in dielectric properties.

From the results shown in Table 2, it can be seen that the samples of Comparative Examples 6 to 8 have smaller changes in the moisture absorption and the dielectric constant than Comparative Example 5 impregnated with an epoxy resin equivalent to FR5. This is considered to be due to the fact that the properties of the epoxy resin itself appeared because the epoxy resin having low moisture absorption was used as described above. Further, Examples 2-1 to 2-2
Is the case where the epoxy resin and the skeleton of the curing agent were made to have the same structure after using the low hygroscopic epoxy resin, and the change in the moisture absorption and the change in the dielectric constant were higher than those in Comparative Examples 6 to 8. Can be seen to be even smaller.

Further, as in Examples 2-3 to 2-6, phenol novolak glycidyl ether, cresol volac glycidyl ether, bisphenol A
It can be seen that when the epoxy resin of diglycidyl ether and bisphenol F diglycidyl ether is used and the skeleton of the curing agent and the skeleton of the curing agent have the same structure, the moisture absorption rate is smaller than that of Comparative Example 5. This is, as mentioned above,
Since the distance between the epoxy groups of the epoxy resin and the distance between the hydroxyl groups of the curing agent are almost the same, the epoxy groups and the hydroxyl groups react efficiently, the moisture absorption rate decreases, and as the moisture absorption rate decreases, the dielectric constant decreases. Is also small.

The results for the printed wiring board shown in Table 3 also have substantially the same tendency as those shown in Table 2, and the resin contained in the insulating layer was formed of epoxy resin excluding glycidyl ether groups. When the skeleton and the skeleton of the curing agent excluding the hydroxyl group have the same structure, a printed wiring board having low water absorption and excellent dielectric properties can be obtained.

Finally, the results shown in Table 4 will be described. From the results shown in Table 4, it is understood that the moisture absorption of the printed wiring boards of Comparative Examples 14 to 16 is smaller than that of Comparative Example 13 using an epoxy resin equivalent to FR5. this is,
This is because when the cured product of the low-hygroscopic epoxy resin covers the substrate surface, moisture condensation at the interface between the substrate and the resin can be suppressed.

Further, when a low hygroscopic epoxy resin was used as in Examples 5-1 and 5-2 and the skeleton of the epoxy resin and the skeleton of the curing agent were the same, the comparative examples 14 to 16 It can be seen that the moisture absorption is smaller. This is because, as described above, the epoxy group and the hydroxyl group react efficiently, and the moisture absorption rate decreases. Due to this low water absorption, the printed wiring boards of Examples 5-1 and 5-2 have a dielectric constant. It can be said that the characteristics are also excellent.

Further, in the results shown in Table 4, the phenol novolak, cresol novolak and phenol novolak used in Examples 5-3 to 5-6 were compared with the epoxy resin used in Comparative Example 13.
Examples 5-1 to 5-2 show that the bisphenol A type and the bisphenol F type epoxy resin have low moisture absorption.
It can be seen that the same effect as described above can be obtained.

Next, considering the amount of resin impregnation at the time of the first resin impregnation, the amount of moisture absorption in Comparative Example 13 and Comparative Example 17 is the same, and the amount of moisture absorption in Examples 4-1 and 4-2 is the same. Since the amount is smaller than that of Comparative Example 13, it can be seen that the effect is exhibited when the resin impregnation amount in the first resin impregnation is 5% by weight or more with respect to the weight of the base material. Therefore, the resin impregnation amount at the time of the first resin impregnation of a resin composition containing a glycidyl ether type epoxy resin and a curing agent having the same chemical structure except that the glycidyl ether group of the epoxy resin is replaced by a hydroxyl group is based on 5% by weight of material
Otherwise, the effect is not exhibited.

The present invention provides an efficient reaction between an epoxy group and a hydroxyl group by combining a glycidyl ether type epoxy resin with a curing agent having the same chemical structure except that the glycidyl ether group of the epoxy resin is replaced with a hydroxyl group. As a result, the residual ratio of the hygroscopic unreacted hydroxyl groups in the cured product can be reduced. Therefore, it is possible to provide a resin composition for electrical insulation which gives a cured product having a lower hygroscopicity than when each is used alone. In addition, since the resin composition has low hygroscopicity, a change in dielectric properties due to moisture absorption can be suppressed, so that it is possible to provide an electrically insulating resin composition that gives a cured body having excellent dielectric properties.

By using the resin composition of the present invention,
A prepreg having low moisture absorption and excellent dielectric properties can be provided, and a printed wiring board having low moisture absorption and excellent dielectric properties can be obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H05K 3/00 (72) Inventor Masao Hasegawa 1006 Odakadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (13)

[Claims] 1. An epoxy resin selected from the group consisting of a naphthol-modified glycidyl ether type epoxy resin and a glycidyl ether type epoxy resin containing a biphenyl group, and a glycidyl ether group of the epoxy resin substituted by a hydroxyl group. Is a thermosetting resin composition comprising: a curing agent having the same chemical structure. 2. A thermosetting composition comprising a substrate, a glycidyl ether type epoxy resin impregnated in the substrate, and a curing agent having the same chemical structure except that the glycidyl ether group of the epoxy resin is replaced by a hydroxyl group. A prepreg comprising a resin composition. 3. A glycidyl ether type epoxy resin,
Bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, tetrabromobisphenol A diglycidyl ether, phenol novolac glycidyl ether, cresol novolac glycidyl ether, naphthol-modified glycidyl ether type epoxy resin, and biphenyl novolac glycidyl ether type epoxy resin The prepreg according to claim 2, which is at least one selected from the group consisting of: 4. The prepreg according to claim 2, wherein the substrate is at least one substrate selected from the group consisting of glass woven fabric, glass nonwoven fabric, wholly aromatic polyester nonwoven fabric, aramid woven fabric, and aramid nonwoven fabric. . 5. At least one insulating layer formed from a thermosetting resin composition or a substrate impregnated with the resin composition, and a circuit pattern formed on at least one surface of the insulating layer. Wherein the resin composition comprises a glycidyl ether type epoxy resin, and a hardening agent having the same chemical structure except that the glycidyl ether group of the epoxy resin is replaced with a hydroxyl group. substrate. 6. A glycidyl ether type epoxy resin,
Bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, tetrabromobisphenol A diglycidyl ether, phenol novolac glycidyl ether, cresol novolac glycidyl ether, naphthol-modified glycidyl ether type epoxy resin, and biphenyl novolac glycidyl ether type epoxy resin The printed wiring board according to claim 5, which is at least one selected from the group consisting of: 7. The print according to claim 5, wherein the substrate is at least one substrate selected from the group consisting of glass woven fabric, glass nonwoven fabric, wholly aromatic polyester nonwoven fabric, aramid woven fabric, and aramid nonwoven fabric. Wiring board. 8. The printed wiring board according to claim 5, wherein the circuit pattern is formed from metal foil or metal plating. 9. A thermosetting resin composition containing a glycidyl ether type epoxy resin and a curing agent having the same chemical structure except that the glycidyl ether group of the epoxy resin is replaced with a hydroxyl group, Drying, then impregnating the base material impregnated with the resin composition with a resin composition different from the resin composition, and drying to form a prepreg, and a metal foil on at least one surface of the prepreg And a step of forming a circuit pattern. 10. The amount of impregnation of a thermosetting resin composition containing a glycidyl ether type epoxy resin and a curing agent having the same chemical structure except that a glycidyl ether group of the epoxy resin is substituted with a hydroxyl group is the same as that of the base material. The method according to claim 9, wherein the amount is at least 5% by weight based on the total weight of the printed wiring board. 11. A glycidyl ether type epoxy resin, wherein bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, tetrabromobisphenol A diglycidyl ether, phenol novolak glycidyl ether, cresol novolac glycidyl ether, naphthol-modified glycidyl ether type epoxy resin, The method for producing a printed wiring board according to claim 9, wherein the method is at least one selected from the group consisting of biphenyl novolak glycidyl ether type epoxy resin. 12. The base material is a glass woven fabric, a glass nonwoven fabric,
The method for producing a printed wiring board according to claim 9, wherein the method is at least one type of substrate selected from the group consisting of a wholly aromatic polyester nonwoven fabric, an aramid woven fabric, and an aramid nonwoven fabric. 13. The method according to claim 9, wherein the metal foil is a copper foil.