JPS6262750A - Manufacture of printed wiring board material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] 〔Technical field〕 The present invention relates to a method for manufacturing printed wiring board material.

[Background technology]

The following method is one of the continuous manufacturing methods for printed wiring board materials.

A long strip-shaped base material made of a material such as glass cloth 2 paper is continuously fed and impregnated with a resin such as an unsaturated polyester resin or an epoxy resin. If necessary, lamination molding of predetermined sheets of this resin-impregnated base material or lamination of sheet-like materials such as metal foil or release film is performed. After that, the resin in the base material is cured while being transferred continuously in a curing furnace, and the resin is cut into predetermined lengths to continuously obtain printed wiring board materials. Production efficiency was high because the method involved curing and manufacturing printed wiring board materials continuously.

However, the printed wiring board material obtained by this manufacturing method has voids (bubbles) formed inside and many craters formed on the surface, so that the slip layer insulation resistance is reduced. In addition, in this manufacturing method,
Resin gelling time.

The curing characteristics of the resin, such as its maximum heat generation temperature, were also poor, and this had a negative impact on the quality of the printed wiring board material obtained. Moreover, in the case where metal foil was laminated on the surface, the metal foil had shrunk and wrinkled, and the beer strength (peel strength) of the metal foil had decreased.

Thus, according to this manufacturing method, it is difficult to obtain a printed wiring board material of good quality.

[Purpose of the invention]

In view of the above circumstances, an object of the present invention is to provide a method for manufacturing a printed wiring board material that can obtain a printed wiring board material of good quality.

[Disclosure of the invention]

In order to achieve the above object, the inventors have conducted various studies. First, the inventors investigated the causes of adverse effects on quality in conventional manufacturing methods.

As a result, it was found that the quality was greatly influenced by the temperature and humidity conditions during impregnation. In other words, when the base material is impregnated with resin, the resin on the surface of the resin-impregnated base material absorbs a large amount of moisture, and the properties of the resin change depending on the temperature, resulting in a poor quality printed wiring board material. Ta.

Therefore, the inventors thought that it would be possible to obtain a high-quality printed wiring board material by impregnating the base material with resin in an atmosphere of low humidity and moderate temperature, and conducted various experimental studies. So, here we have completed this invention.

That is, the present invention impregnates a continuously supplied long strip-shaped base material with a resin and cures the resin to continuously obtain a printed wiring board material at an absolute humidity of 0.01.
5 kg/kg or less and temperature 15°C or less l-40
The gist of this invention is a method for manufacturing a printed wiring board material, which is characterized by impregnating a base material with a resin in an atmosphere below .degree.

Figure 1 shows the carrier psychrometric diagram at standard atmospheric pressure (760mHg). In the figure, the vertical axis represents absolute humidity and the horizontal axis represents temperature. In FIG. 1, the base material is impregnated with the resin in an atmosphere within the shaded area.

If the base material is impregnated with resin in an atmosphere where the absolute humidity exceeds 0.015 kg/kg, the insulation resistance of the slip layer will decrease, internal voids and surface craters will occur, the gelation time of the resin will change, and the maximum of the resin will decrease. This results in a decrease in the curing characteristics of the resin, such as the heat generation temperature, and the quality of the resulting printed wiring board material deteriorates. In this respect, the manufacturing method of the printed wiring board material according to the present invention has an absolute humidity of 0.015 kg/kg.
By impregnating the base material with a resin in the following atmosphere, moisture absorption of the resin on the surface of the resin-impregnated base material can be suppressed, and a high-quality printed wiring board material can be obtained. In addition, if the temperature is lower than 15°C, the resin viscosity will increase and the impregnation rate will be slow, making it impractical. If the temperature is higher than 40°C, the curing behavior of the resin may change during long-term continuous production. In some cases, problems may occur such as the crosslinking monomer scattering. To impregnate a base material with resin in an atmosphere with an absolute humidity of 0.015 kg/kg or less and a temperature of 15°C or more and 40°C or less, for example, the impregnation process is performed in one room, and the The absolute humidity may be set to 0.015 kg/kg or less, and the temperature may be set to 15°C or more and 40°C or less.

Impregnating the base material with resin in an atmosphere with an absolute humidity of 0.015 kg/kg or less and a temperature of 15°C or more and 40°C or less is a necessary condition for obtaining a high-quality printed wafer board material. A more preferable condition is to impregnate the base material with the resin so that the resin content of the resulting printed wiring board material is 30 to 80 wt%. If it is less than 30 wt%, blistering of the base material is likely to occur when the resin is cured, and if it is more than 80 wt%, etching may occur when processing the obtained printed wiring board material into a printed wiring board. This is because the warpage tends to become larger later.

The printed wiring board material may be obtained in the form of a long strip, or may be cut into a desired size with a cutter or the like after the resin has hardened. A printed wiring board material may be obtained by laminating and molding a plurality of resin-impregnated base materials before the resin is cured.

Furthermore, a printed wiring board material may be obtained by laminating a metal foil such as copper foil on at least one surface (single surface or both surfaces) of the resin-impregnated base material before the resin is cured. Instead of metal foil, a release film may be laminated on the surface (one or both sides) of the resin-impregnated base material, or a metal foil may be laminated on one side of the resin-impregnated base material and a release film on the other side. They may be laminated. A printed wiring board material may be obtained by laminating and molding a plurality of resin-impregnated base materials and then laminating metal foil or a release film.

Laminate molding of resin-impregnated base materials and lamination of metal foil and release film at O~50kg/cn! If the process is carried out at a low pressure, it becomes a manufacturing method called a pressureless continuous method, but it may also be done in this way.

The various printed wiring board materials obtained as described above have different forms, but the absolute humidity is 0.
．． 015 kg/kg or less, and the base material is impregnated with resin in an atmosphere with a temperature of 15"C or lower and 40°C or higher, so the hot water layer insulation resistance is high and there are no internal voids or surface craters. , all of them result in high-quality printed wiring board materials.Furthermore, during manufacturing, the curing properties of the resin, such as the gelation time of the resin and the maximum heat generation temperature of the resin, are improved, so from this point of view, the material is of high quality. It can be used as a material for printed wiring boards.In particular, when metal foil is laminated on the surface, the metal foil does not shrink or wrinkle, and the beer strength of the metal foil is high.

The resin content mentioned above generally represents the weight ratio of the resin to the total weight of the printed wiring board material, but in the case of a board with a metal foil or release film laminated on the surface, the resin content is the weight ratio of the resin to the total weight of the printed wiring board material. It represents the weight ratio of resin to the total weight of something called a substrate.

Next, an example of the manufacturing method of the printed wiring board material according to the present invention will be explained together with a comparative example. (Example 1) 400 parts by weight of polyester resin (YDB-400 manufactured by Tobu Kasei Co., Ltd.) was placed in a Yotsuro flask. , butadiene acrylonitrile copolymer liquid rubber (CT manufactured by Ube Industries, Ltd.)
100 parts by weight of BNI 300X8), 25 parts of styrene
0 parts by weight, 2.6 parts by weight of triethylamine, and 0.2 parts by weight of hydroquinone, and after reacting at 100'C without introducing air until the acid value became 1.5 or less, methacrylic acid was added. Add 80 parts by weight of
The mixture was reacted at 15°C for 5 hours to obtain a mixture of rubber-modified vinyl ester and styrene with an acid value of 0.3. Cumene hydroperoxide was added to this mixture in an amount of 1 wt%, and the resulting resin was applied to seven glass cloth substrates (WE-18-BS manufactured by Nittobo Co., Ltd.) that were continuously supplied at a relative humidity of 55%. (Temperature 30" C1 absolute humidity 0.015
It was impregnated continuously in an atmosphere of 1 qr/kg), and when it was sufficiently penetrated, electrolytic copper foil (TST○ manufactured by Furukawa Circuit Foil Co., Ltd., thickness 18 μm) was laminated on both sides.
A printed wiring board material having a thickness of 1.6 mm was obtained by heat curing at 00'C for 20 minutes and at 160C for 20 minutes.

The resin content of this printed wiring board material was 43 wt%.

(Example 2.3 and Comparative Example 1) The relative temperature in the step of impregnating the base material with resin was set to 42% (temperature 30°C, absolute humidity 0.011 kg/kg), 3
0% (/I! S degree 30°C: 5.': 1.! Humidity 0.
OO8kg/kg).

84% (temperature 30°C1 absolute humidity 0.023 kg/
A printed wiring board material was obtained in exactly the same manner as in Example 1, except that the weight was changed to 1 kg).

As described above, the obtained printed wiring board materials were examined for the presence or absence of copper foil shrinkage wrinkles and voids inside the board, as well as water content, creeping insulation resistance, copper foil peel strength, resin curing characteristics, resin gelation time, and resin hardness. The maximum exothermic temperature was measured, and the results are shown in Table 1. Regarding the measurement of copper foil beer strength, JIS C6481-5
．． 7, and for the measurement of hot water layer insulation resistance, please refer to J.
It was carried out according to 5.11 of IS C6481. Also,
Regarding the measurement of the gelation time of the resin and the maximum exothermic temperature of the resin, the temperature of the constant temperature bath was set to 100°C, and the temperature of the measurement sample was measured from 85°C to 105°C.
It was carried out according to 4.6 of K 6901.

As shown in Table 1, it can be seen that Examples 1 to 3 have lower moisture content than Comparative Example 1, and there are no copper foil shrinkage wrinkles or voids inside the substrate. In addition, creepage insulation resistance is high,
The copper foil peel strength is also increased. Moreover, it can be seen that the gelation time of the resin is short, the maximum heat generation temperature of the resin is high, and the curing characteristics of the resin are also improved.

(Example 4) The resin used in Example 1 was continuously supplied to two glass cloth substrates (the same as in Example 1) and a glass paper substrate (EP-40 manufactured by Nippon Vilene Co., Ltd.).
35) Relative humidity 65% (temperature 25℃, absolute humidity 0
．． 013 k+r/kg), and when it is sufficiently penetrated, electrolytic copper foil (Example 1) is applied on both sides.
) were laminated and heated at 100℃ for 20 minutes and then at 160℃.
Heat cure for 20 minutes to reduce the thickness of the composite structure to 1.
No. 61 printed wiring board material was obtained. The resin content of this printed wiring board material was 65 wt%.

(Examples 5 and 6 and Comparative Example 2) The relative humidity in the step of impregnating the base material with resin was 50% (temperature 25 ° C., absolute humidity 0.01 kg/kg), 35
% (Temperature 25°C1 Absolute humidity 0.007kg/kg)
, 95% (temperature 25°C2 absolute humidity 0.021k
A printed wiring board material was obtained in exactly the same manner as in Example 4, except that the weight ratio was changed (g/kg).

The printed wiring board materials obtained above were subjected to the same measurements as in Examples 1 to 3 and Comparative Examples, and the results are shown in Table 2.

As shown in Table 2, Examples 4 to 6 of composite configurations
It can also be seen that the moisture content is lower than that of Comparative Example 2, and there are no copper foil shrinkage wrinkles or voids inside the substrate. In addition, the creeping insulation resistance is high, and the copper foil beer strength is also high. Moreover, it can be seen that the gelation time of the resin is short, the maximum heat generation temperature of the resin is high, and the curing characteristics of the resin are also improved.

(Example 7) Cumene hydroperoxide was added to a mixture of vinyl ester and styrene obtained in the same manner as in Example 1, except that CTBNI 300X8 was not used.
．． 5wt% and benzoyl peroxide (B, P, O
,) was added at 0.5 wt%.

A kraft paper base impregnated with 12 wt% of melamine resin (H manufactured by Sanyo Kokusaku Pulp Co., Ltd.) using the resin obtained in this way.
L-10) 5 sheets were continuously impregnated in an atmosphere of relative humidity 35% (temperature 35℃, absolute humidity 0.012 kg/kg), and when it was sufficiently penetrated, electrolytic copper foil (Furukawa Circuit Foil Co., Ltd. A polyethylene terephthalate film with a thickness of 5011 m was laminated on one side and a polyethylene terephthalate film with a thickness of 5011 m on the other side.
By heating and curing at 160° C. for 20 minutes, a printed wiring board material having a thickness of 1.61 cm and having a copper foil laminated on one side was obtained. The resin content of this printed wiring board material is 60wt%
Met.

(Examples 8 and 9 and Comparative Examples 3 and 4) The relative humidity in the step of impregnating the base material with resin was 28% (temperature 35 ° C., absolute humidity 0.01 kg/kg), 23
% (temperature 35℃, absolute humidity 0.OO8kg/+r)
, 64% (temperature 35℃, absolute humidity 0.023K)
g/kg).

48% (temperature 35℃, absolute humidity 0.017 kg/k
A printed wiring board material was obtained in exactly the same manner as in Example 7 except that g) was changed.

Regarding the obtained printed wiring board materials, Examples 1 to 6 and Comparative Example 1, except that craters on the surface of the board were examined instead of examining voids inside the board.
The same measurements as in 2 were carried out and the results are shown in Table 3.

As shown in Table 3, Example 7 in which copper foil was laminated on one side
It can be seen that Samples 1 to 9 also have a lower water content than Comparative Examples 3 and 4, and there are no wrinkles or craters on the surface of the 7th grade. In addition, the hot water layer insulation resistance is high, and the copper foil peel strength is also high. Moreover, it can be seen that the gelation time of the resin is short, the maximum heat generation temperature of the resin is high, and the curing characteristics of the resin are also improved.

As we have seen above, absolute humidity is 0.015 kg/k
"Printed wiring board material obtained by impregnating with resin in an atmosphere with a temperature of 15°C or more and 40°C or less" is
All of them are of good quality.

In addition, in the examples, the relationship between resin content and water content is expressed by the following formula (
The relationship was 1).

W≦O, OO3X A (t) where W: water content (ivt%) A: resin content (wt%) The method for manufacturing the printed wiring board material according to the present invention is not limited to the above embodiments.

〔Effect of the invention〕

As described above, the manufacturing method of the printed wiring board material according to the present invention has an absolute humidity of 0.015 kg/kg.
or less, and is characterized by impregnating the base material with the resin in an atmosphere with a temperature of 15°C or more and 40°C or less,
It is possible to obtain high quality printed wiring board materials.

[Brief explanation of the drawing]

FIG. 1 is a carrier psychrometric diagram showing the range of atmosphere in the step of impregnating a base material with a resin in the method for manufacturing a printed wiring board material according to the present invention.

Claims (6)

[Claims] (1) Absolute humidity is 0.015 kg/kg or less when impregnating a continuously supplied long strip-shaped base material with resin and curing this resin to continuously obtain a printed wiring board material, A method for producing a printed wiring board material, which comprises impregnating a base material with a resin in an atmosphere at a temperature of 15°C or higher and 40°C or lower. (2) The method for manufacturing a printed wiring board material according to claim 1, wherein the base material is impregnated with a resin so that the resin content is 30 to 80 wt%. (3) The method for manufacturing a printed wiring board material according to claim 1 or 2, wherein a plurality of resin-impregnated base materials are laminated and molded before the resin is cured. (4) Laminate molding of multiple resin-impregnated base materials is 0 to 50 kg.
A method for manufacturing a printed wiring board material according to claim 3, which is carried out at a low pressure of /cm^2. (5) The printed wiring board material according to any one of claims 1 to 4, wherein metal foil is laminated and molded on at least one surface of the resin-impregnated base material before the resin is cured. manufacturing method. (6) The method for producing a printed wiring board material according to claim 5, wherein the metal foil is laminated at a low pressure of 0 to 50 kg/cm^2.