JP2000265368A - Production of coated fabric impregnated with thermosetting resin, copper-clad laminate and vertical- type drying oven - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for easily producing the subject coated fabric, to obtain a copper-clad laminate therefrom, and to provide a vertical-type drying oven for producing the above coated fabric. SOLUTION: This method for producing the subject coated fabric comprises impregnating a fibrous base material 10 with a thermosetting resin varnish 2 followed by passing the fibrous base fabric thus impregnated through a vertical drying oven 7 to vaporize the a dilutive solvent; wherein the base fabric 10 being in movement through the drying oven 7 is heated by radiant heat from a heating unit (a panel heater 15) along with supporting the base fabric 10 by the aid of wind pressure as a result of blowing a gas against both surfaces thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a thermosetting resin impregnated coated cloth used for a laminate for a printed wiring board.
The present invention relates to a copper-clad laminate and a vertical drying oven.

[0002]

2. Description of the Related Art In general, a prepreg used for a printed wiring board is manufactured by cutting a thermosetting resin impregnated coating cloth. After a fibrous base material is impregnated with a resin varnish obtained by diluting a thermosetting resin with an organic solvent, the solvent is volatilized in a drying furnace to make the thermosetting resin into a B-stage state.

When a glass cloth is used as a fibrous base material,
Generally, a thermosetting resin impregnation method is a dip method or a kiss coat method, and a drying furnace is a vertical method. The drying temperature in the vertical drying furnace varies depending on the resin used, but is generally between 130 ° C and 200 ° C.

The thickness of a glass cloth used as a fibrous base material is generally 30 μm to 200 μm. The heating method in a vertical heating furnace is to blow hot air onto a fibrous base material impregnated with a thermosetting resin. A hot air blowing method is used.

In this hot air blowing method, tension is applied to the fibrous base material to prevent the fibrous base material conveyed in the drying furnace from fluttering or meandering due to wind pressure. . The tension of the fibrous base material depends on the thickness of the fibrous base material, but is generally larger than 20 kg / m and 50 k.
g / m or less.

[0006]

As described above, since a large tension is applied to the fibrous base material, the stress applied to the fibrous base material causes the solvent to evaporate and the thermosetting resin to enter the B-stage state. Even after the drying, it remains on the fibrous base material. The stress remaining in the fibrous base material is hardly released by the pressure of the press in the next pressing step, and remains in the copper clad laminate manufactured using the cut prepreg.

[0007] The stress remaining in the copper-clad laminate is released in a processing step of the copper-clad laminate, for example, an etching step, and causes a large dimensional change, warpage, and twist. A large dimensional change during this process causes a shift between the through-hole or the pad portion and the resist mask, resulting in a defective product. In addition, the torsion causes a trouble at the time of component mounting. Therefore, in order to reduce the stress acting on the fibrous base material during the production of the thermosetting resin impregnated coated cloth, measures such as increasing the cloth density or decreasing the coating speed have been taken, but sufficient measures have been taken. The stress has not been reduced.

On the other hand, tension is applied to the fibrous base material even when the thermosetting resin varnish is applied. Particularly, a vertical type coating machine using a glass cloth as the fibrous base material has a large tension. Working.

As a method for removing the stress due to the tension, Japanese Patent Application Laid-Open No. 9-307236 discloses a method in which a drying oven for removing the stress is provided after the coating machine. However, the conventional method disclosed in this publication has a problem in that the coating conditions for matching the performance of the thermosetting resin-impregnated coating cloth and the conditions for stress removal are difficult to match, and it takes time to set the conditions.

[0010] The present invention has been made in view of the above problems, and a method of manufacturing a thermosetting resin impregnated coated cloth which can be easily manufactured and reduces residual stress, a copper-clad laminate, and a vertical drying oven The purpose is to provide.

[0011]

In order to solve the above-mentioned problems, the invention according to the first aspect is, as shown in FIG. 1, after a thermosetting resin varnish 2 is impregnated into a fibrous base material 10 and then heated. In the method for producing a thermosetting resin impregnated coated cloth for passing the fibrous base material 10 impregnated with the curable resin varnish 2 into the vertical drying furnace 7 and volatilizing the diluting solvent, the inside of the vertical drying furnace 7 is Heating unit (panel heater 15) for moving fibrous base material 10
Is heated by the radiant heat of the fiber substrate 10 and a gas is blown to both surfaces of the moving fibrous substrate 10 so that the fibrous substrate 1
It is characterized by supporting 0.

According to the first aspect of the present invention, after the fibrous base material 10 is impregnated with the thermosetting resin varnish 2, the fibrous base material 10 is passed through the vertical drying furnace 7, and the diluted solvent Is volatilized to obtain a thermosetting resin impregnated coated cloth. The fibrous base material 10 moving in the vertical drying furnace 7 volatilizes the diluting solvent by radiant heat from the heating unit (panel heater 15), and the fibrous base material 10 is supported by the wind pressure of gas blown from both sides. Therefore, fluttering and meandering of the fibrous base material 10 can be prevented, and the tension applied to the fibrous base material 10 can be reduced. Therefore, it is possible to reduce the stress remaining in the thermosetting resin impregnated coated cloth caused by the application of the tension.

In particular, in order to increase the production efficiency, even if the furnace length of the vertical drying furnace 7 is increased, the fibrous base material
Since the fibrous base material 10 is supported by the gas pressure blown to zero, the swing of the fibrous base material 10 can be reduced, and the fibrous base material 10 comes into contact with the inner wall of the vertical drying furnace 7 and is damaged. Can be prevented.

Further, since it is not necessary to set conditions for removing stress as in the conventional case, it is easy to manufacture a thermosetting resin impregnated coated cloth.

As the gas to be blown, hot air is preferable. The wind pressure of the gas is not particularly limited as long as the wind speed is such that the swinging of the fibrous base material 10 can be prevented.
Min to 10 m / min.

According to a second aspect of the present invention, in the first aspect, a tension applied to the fibrous base material 10 moving in the vertical drying furnace 7 is applied to the entire width of the fibrous base material 10. On the other hand, the weight is set to 20 kg or less.

According to the second aspect of the present invention, the tension applied to the fibrous base material 10 is set to 20 kg or less with respect to the width of the fibrous base material 10.
The stress remaining on the thermosetting resin-impregnated coated fabric after production can be sufficiently reduced.

The applied tension varies depending on the thickness and width of the fibrous base material 10, but is preferably 5 kg or less. By setting the tension applied to the fibrous base material 10 to 5 kg or less,
Further, residual stress can be reduced.

According to a third aspect of the present invention, as shown in FIG. 2, a prepreg 23 produced by cutting the thermosetting resin impregnated coated fabric produced by the production method according to the first or second aspect is manufactured. The present invention is characterized in that the used copper-clad laminate 29 is used.

According to the third aspect of the present invention, the thermosetting resin impregnated coated cloth with less stress is cut and processed into the prepreg 23, and the copper-clad laminate 29 is manufactured using the prepreg 23. Therefore, dimensional change and warpage of the copper clad laminate 29 can be reduced.

According to a fourth aspect of the present invention, in the vertical drying furnace 7 for conveying the fibrous base material 10 impregnated with the thermosetting resin varnish 2 and volatilizing the diluting solvent, the conveying path of the fibrous base material 10 is provided. And a heating means (panel heater 15) for heating the fibrous base material 10 by radiant heat, and disposed on both sides of the fibrous base material 10 to be conveyed. A substrate swing preventing nozzle 17 for injecting gas is provided.

According to the fourth aspect of the present invention, the vertical drying furnace 7 is provided with a heating means (panel heater 1) for applying radiant heat.
5) and the substrate swing prevention nozzle 17, the manufacturing method according to claim 1 described above can be realized with a simple configuration.

The heating means is a panel heater 15.
However, other heaters may be used. Further, it is preferable that the base material swing preventing nozzle 17 blows out hot air.

[0024]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. The prepreg manufacturing apparatus 1 according to the embodiment of the present invention includes a base material supply unit 3, a varnish impregnation unit 5, a vertical drying furnace 7, a drawer roll 8, and a cutting machine 9.

The base material supply unit 3 includes a base material roll 11 wound around a long fibrous base material 10 and a tension control roll for controlling the tension applied to the fibrous base material 10 drawn from the base material roll 11. 13, the tension of the fibrous base material 10 supplied to the varnish-impregnated portion 5 is adjusted.

The varnish impregnating section 5 impregnates the fibrous base material 10 with the thermosetting resin varnish 2 by a dip method or a kiss coat method.

As the thermosetting resin of the thermosetting resin varnish 2, phenol resin, epoxy resin, polyimide resin,
It is preferable to use a polyester resin, a cyanate ester resin, a resin having a benzoxazine ring, and a resin having a triazine ring.

The vertical drying furnace 7 vertically conveys the fibrous base material 10 impregnated with the thermosetting resin varnish 2, and volatilizes the dilution solvent by heating. The vertical drying furnace 7 includes a plurality of radiation panels 15 arranged along the transport path.
And a substrate swing preventing nozzle 17 for supporting the fibrous substrate 10 by blowing a gas.

The radiation panels 15 are provided on both sides of the transport path for transporting the fibrous base material 10, and heat the fibrous base material 10 by radiant heat. Therefore, since heating is not performed by blowing hot air as in the related art, it is possible to prevent the fibrous base material 10 from shaking or rattling due to blowing hot air.

The base material swing preventing nozzle 17 is provided at a position opposing the conveying path, and supports the fibrous base material 10 by blowing gas to both side surfaces of the fibrous base material 10.
The substrate swing preventing nozzles 17 are provided for each pair sandwiching the transport path, and any number of pairs may be provided according to the length of the transport path.

In the vertical drying furnace 7, a tension detecting roll 19 for detecting the tension of the fibrous base material 10 being conveyed is provided. A roll 21 is provided, and a predetermined tension is applied to the fibrous base material 10 by adjusting the tension control rolls 13 and 21 according to the detection value of the tension detection roll 19.

The tension applied to the fibrous base material 10 is 20K
g, and preferably varies depending on the thickness and width of the fibrous base material 10, but is particularly preferably 5 kg or less.

The fibrous base material 1 after passing through the vertical drying furnace 7
0 is cut to a predetermined size by the cutting machine 9 to produce the prepreg 23 (see FIG. 2).

Next, the manufacturing method according to the present embodiment will be described. The fibrous base material 10 pulled out from the drawer roll 11 is impregnated with the thermosetting resin varnish 2 by the varnish impregnating section 5 and is conveyed to the vertical drying furnace 7.

The fibrous base material 10 transported to the vertical drying furnace 7
Is transported up and down in the vertical drying furnace 7 while being heated by the radiant heat of the panel heater 15. Thereby, the diluting solvent contained in the thermosetting resin varnish 2 is volatilized.

In the vertical drying furnace 7, the fibrous base material 1
Hot air is blown out from a pair of base material swing prevention nozzles 17 provided opposite to each other with the conveyance path of No. 0 in between to support the moving fibrous base material 10, and the fibrous base material 10 flaps and swings. Is further reduced, and the tension applied to the fibrous base material 10 is reduced. In addition, any number of pairs of the base material preventing nozzles 17 may be provided,
There is no limit on the number.

[0037]

EXAMPLE 1 90 parts by weight of a brominated bisphenol A type epoxy resin (epoxy equivalent 500) and 10 of a cresol novolak type epoxy resin (epoxy equivalent 220) were used as the thermosetting resin used for the thermosetting resin varnish 2. Parts by weight,
5 parts by weight of diandiamide (DICY) as a curing agent, 0.2 parts by weight of 2-ethyl 4-methylimidazole (2E4MZ) as a curing accelerator, 50 parts by weight of methyl ethyl ketone (MEK) as a diluting solvent, dimethylformamide ( DMF) was blended in an amount of 10 parts by weight.

Using this thermosetting resin varnish 2, FIG.
The prepreg manufacturing apparatus 1 shown in FIG. 1 is used to impregnate glass cloth of the MIL specification standard 2116 type, and the tension control rolls 13 and 21 so that the tension in the furnace becomes 5 kg or less with respect to the entire width of the fibrous base material 10. Was adjusted to obtain a thermosetting resin-impregnated coated cloth, and the coated cloth was cut to produce a prepreg.

As shown in FIG. 2, an 18 μm electrolytic copper foil 25 is laminated on the outside of the
Was heated at 185 ° C. and 30 kg / cm ² for 90 minutes to obtain a 0.2 mm-thick copper-clad laminate 29.

[0040]

Example 2 A copper foil laminated board 29 was obtained in the same manner as in Example 1 except that a polyimide resin (trade name: Kelimide, Rhone-Plain) was used as the thermosetting resin.

COMPARATIVE EXAMPLE 1 A thermosetting resin varnish 2 similar to that of Example 1 and a glass cloth as the fibrous base material 10 were used, and a vertical drying furnace using a conventional heating method by blowing hot air instead of the panel heater 15 was used. And the tension applied to the fibrous base material 10 is 30 kg with respect to the entire width of the fibrous base material 10.
Then, a thermosetting resin impregnated coated cloth was manufactured, and this was cut to manufacture a prepreg 23. The prepreg 23 was used to obtain a copper-clad laminate 29 under the same conditions as in Example 1 described above.

Comparative Example 2 The same thermosetting resin varnish 2 and fibrous base material 10 as in Example 1 were applied to fibrous base material 10 using the same conventional vertical drying oven as in Comparative Example 1. The tension was set to 30 kg with respect to the entire width of the fibrous base material 10 to produce a thermosetting resin impregnated coated cloth, which was cut into a prepreg, and then the prepreg was used. To obtain a copper-clad laminate.

The dimensional change rate and warpage of the copper-clad laminate 29 manufactured according to the above-described Examples and Comparative Examples were measured, and the results are shown in Table 1 below.

[0042]

[Table 1]

In Table 1, the dimensional change is a value measured after etching each copper clad laminate 29 and heating it at 170 ° C. for 30 minutes. The amount of warpage is 500 mm (length) × 500 m.
This shows the amount of bounce after heating the copper-clad laminate 29 of m (horizontal) at 170 ° C.

As is clear from Table 1, in Examples 1 and 2, the dimensional change rate could be reduced as compared with Comparative Examples 1 and 2. Further, the warpage amount was 0.2 mm in both Comparative Examples 1 and 2 which were about 1.0 mm, and the warpage amount could be reduced.

As described above, the dimensional change and the amount of warpage of the copper-clad laminate 29 can be reduced because the tension applied to the fibrous base material 10 in the prepreg manufacturing process is reduced. This is because it has been reduced.

[0046]

According to the first aspect of the present invention, the fibrous base material moving in the vertical drying oven volatilizes the diluting solvent by radiant heat from the heating unit, and the fibrous base material is blown from both sides. Because it is supported by the wind pressure of the attached gas,
It is possible to prevent fluttering and meandering of the fibrous base material, reduce the tension applied to the fibrous base material, and reduce the stress remaining in the thermosetting resin impregnated coated cloth caused by the application of the tension. In addition, since it is not necessary to set conditions for removing stress, it is easy to manufacture a thermosetting resin impregnated coated cloth.

According to the second aspect of the present invention, the tension applied to the fibrous base material is 20 kg
Because of the following, the stress remaining in the thermosetting resin impregnated coated cloth can be sufficiently reduced by applying the tension.

According to the third aspect of the present invention, since the copper-clad laminate is manufactured using the thermosetting resin impregnated coated cloth with less stress, the dimensional change and warpage of the copper-clad laminate are reduced. it can.

According to the fourth aspect of the present invention, since the vertical drying oven is provided with the heating means for applying radiant heat and the substrate swing preventing nozzle, the above-mentioned effect of the first aspect is achieved. It can be realized with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a prepreg manufacturing apparatus.

FIG. 2 is a sectional view of a copper-clad laminate.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Pre-preg manufacturing apparatus, 2 ... Thermosetting resin varnish, 3 ... Substrate supply part, 5 ... Varnish impregnation part, 7 ... Vertical drying furnace, 8 ... Draw-out roll, 9 ... Cutting machine, 10 ... Fiber base Material: 11: substrate roll, 13: tension control roll, 15: panel heater, 17: substrate swing prevention nozzle, 19: tension detection roll, 21: tension control roll,
23: prepreg, 25: electrolytic copper foil, 27: stainless steel end plate, 29: copper-clad laminate.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takashi Matsuzaki 1500 Oji Ogawa, Shimodate-shi, Ibaraki F-term in the Shimodate Plant of Hitachi Chemical Co., Ltd. AJ12 AJ14 AJ15 AJ22 AJ25 AK05 AK14 AL09 AL13 4L033 AB01 AB04 AC15 CA49 CA55 CA69

Claims (4)

[Claims] A thermosetting resin for impregnating a fibrous base material with a thermosetting resin varnish, passing the fibrous base material impregnated with the thermosetting resin varnish into a vertical drying furnace, and volatilizing a diluting solvent. In the method for producing a resin-impregnated coated cloth, the fiber substrate moving in the vertical drying furnace is heated by radiant heat of a heating unit, and a gas is blown onto both surfaces of the moving fiber substrate to generate a fiber material by wind pressure. A method for producing a thermosetting resin impregnated coated cloth, comprising supporting a substrate. 2. The thermosetting material according to claim 1, wherein the tension applied to the fibrous base material moving in the vertical drying furnace is set to 20 kg or less with respect to the entire width of the fibrous base material. Method for producing impregnated resin coated fabric. 3. A copper-clad laminate using a prepreg produced by cutting the thermosetting resin-impregnated coated fabric produced by the production method according to claim 1 or 2. 4. A vertical drying furnace for conveying a fibrous base material impregnated with a thermosetting resin varnish and evaporating a diluting solvent, provided along a conveying path of the fibrous base material, and provided with a fibrous base material by radiant heat. A heating means for heating the material, and a substrate swing preventing nozzle which is disposed with a fibrous base material conveying path interposed therebetween and injects a gas onto both surfaces of the fibrous base material to be conveyed. Mold drying oven.