JPH0261131A - Fabric for printed wiring board - Google Patents

Abstract

PURPOSE:To provide the title fabric excellent in dielectric properties and usable in the circuits of high-speed-operated electronic equipment, consisting of a fabric made from filament yarn such as of E-glass and polytetrafluoroethylene filament yarn. CONSTITUTION:The objective fabric consisting of a fabric made from (1) at least one kind of filament yarn selected from E-glass, D-glass and silica filament yarns and (2) polytetrafluoroethylene filament yarn. The content of the polytetrafluoroethylene filament yarn is pref. 30-70wt.%. This fabric is impregnated with a solution of a matrix resin such as epoxy resin or polyimide resin followed by drying into a prepreg. A specified number of sheets of this prepreg are laminated and heated under pressure, thus obtaining a printed wiring board.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a fabric for printed wiring boards having excellent dielectric properties.

(Prior art and its problems) Conventionally, E-glass fiber fabric and D-glass! have been used as fabrics for printed wiring boards. Textile fabrics, silica fiber fabrics, aromatic polyamide fibers, aromatic polyester fiber fabrics, etc. have been used.

However, in recent years, as electronic devices have become more sophisticated and more compact, the characteristics required of printed wiring boards have become more sophisticated, such as high-speed calculations and high frequency compatibility. It has also been required that the dielectric properties change little with respect to frequency and temperature. A high dielectric constant causes delays in electrical signals in electronic devices and disturbances in the waveforms of electrical signals, making them unsuitable for use in printed wiring boards for high-speed calculations.

In order to solve these problems, E-glass fibers, silica fibers, and aromatic polyamide fibers with low dielectric constants have been used for printed wiring boards, but they are not sufficient for high-speed calculations and high frequencies. It was not possible to obtain attractive characteristics that could be used.

On the other hand, JP-A No. 82-45750 proposes a fabric for printed wiring boards that has excellent dielectric properties using polytetrafluoroethylene fibers alone or fabrics made of polytetrafluoroethylene fibers and aromatic polyamide d-fine. However, polytetrafluoroethylene fibers alone have poor mechanical strength, and aromatic polyamides have difficulty adhering to matrix resins due to their high crystallinity, resulting in insufficient properties at high temperatures, especially in terms of dimensions. There were problems in that it lacked stability and it was difficult to manufacture high-precision circuits.

The object of the present invention was made in view of the above-mentioned problems, and it is an object of the present invention to provide a novel fabric for printed wiring boards that solves the problems caused by the lack of dielectric properties of conventional printed wiring boards.

(Means for Solving the Problems) The above-mentioned object is to provide at least three f!
This is achieved by a fabric for printed wiring boards characterized by being made of a fabric woven with yarn and polytetrafluoroethylene fiber yarn.

The structure of the fabric used in the present invention is not particularly limited, but
Plain weave is usually used due to its dimensionally stable dimensions. Also, the method of weaving polytetrafluoroethylene i F1a yarn, E glass fiber yarn and/or D glass fiber yarn and/or silica weft yarn is not particularly limited, but they are usually aligned to form warp and weft yarns! ! ! weave

In addition, the composition ratio of polytetrafluoroethylene fiber threads in the fabric is approximately 3 from the balance between the strength and dielectric constant of the fabric.
A composition ratio of 0 to 70% is preferable.

Next, a method for producing a printed wiring board using the fabric of the present invention will be briefly described.

First, a woven fabric is impregnated with a solution such as a matrix resin and dried to form a prepreg. Next, a predetermined number of prepregs are laminated and heated under pressure to obtain a printed wiring board.

The matrix resin is not particularly limited, but polyimide resin, epoxy resin, etc. are usually used. Polyimide resins include addition polymerization type thermosetting, solvent soluble resins, and are used because they are easy to mold.The composition is not particularly limited, but is selected from at least one type of NN'bismaleimide and aromatic or aliphatic diamines. A prepolymer (polyamino bismaleimide) obtained by reacting at least one type of diamine is usually used. Epoxy 8J fat is diglycidyl ether obtained by reacting bisphenol A or halogenated bisphenol with shrimp halohydrin, polyether-type polyglycidyl ether obtained by reacting epihalohydrin with a polyhydric alcohol obtained from bisphenol A and alkylene oxide, and novolak. A polyglycidyl ether of type phenol/formaldehyde resin is used, and a heat-resistant type aromatic polyamine type epoxy curing agent is generally used.

The weight of resin in the entire laminate is usually 30 to 70% by weight. If the amount of resin is too small, the electrical and mechanical properties will be poor or cause deformation, and even if the amount is too much, it will be difficult to form uniformly. Regarding the drying of prepreg, the type of heat-resistant resin,
It is necessary to maintain each appropriate state by changing the resin solution C1, etc.

Lamination press is usually temperature 150~200°C1 pressure 10~
A printed wiring board is obtained by applying pressure in a range of 150 kg/cm' for 1 to 5 hours.

(Function) Polytetrafluoroethylene fiber has extremely high molecular symmetry and is a non-polar polymer, so it has a low dielectric constant, and its dielectric properties vary depending on frequency (60 to 1oIDH2), temperature (90°O to 280°). c) It has characteristics that do not change significantly depending on Ic.

Therefore, a prepreg is made using a base material containing polytetrafluoroethylene fiber, and a printed wiring board on which the prepreg is laminated has excellent dielectric properties.

(Example) Next, the present invention will be specifically explained based on Examples.

Example 1 Polytetrafluoroethylene fiber yarn (200d1500
f> and Eff5 P1. Weft (ECE225110) is used for the warp and weft, density warp 62 wood / 25 mm
, weft 54/25rnrrl knit plain fabric was woven.

Next, an N-methylpyrrolidone solution (51!tffi%) of polyimide resin (Kelimide 601, manufactured by Nippon Polyimide) was prepared as a matrix resin.

This was impregnated with article fabric and dried at 160°C for 7 minutes to obtain a prepreg with 50% by weight of grease added.

8 sheets of this prepreg are stacked and the weight is 50 kg/cm.
Heated at 170°C for 2 hours under pressure to a thickness of l, 2 m.
The printed wiring board of Example 1 of the present invention of m was tested once.

Example 2 Polytetrafluoroethylene fiber yarn (200d/300
f) and D glass fiber yarn (DCE225110) are used for the warp and weft, and the density diameter is 62 pieces/'l 5 mm.
A plain woven fabric was woven with a weft of 54/'l 5 rnrn.

Next, prepregs were laminated in the same manner as in Example 1 to obtain a printed wiring board according to Example 2 of the present invention.

Example 3 Polytetrafluoroethylene fiber yarn (200d/100
f) and silica fiber yarn (SFG!5001/11) are used for the warp and weft, density 62 diameter 725mm, weft 5
A plain woven fabric was produced with 4 fibers/25 mm.

Next, a prepreg was laminated in the same manner as in Example 1 to obtain a printed wiring board of Example 3 of the present invention.

Comparative Example 1 A plain woven fabric was woven using E-glass l'a fibers (EOE2251/(1) for the warp and weft, with a density of 62 threads/25 mm in diameter and 54 threads/25 mm in weft).

Next, prepregs were laminated in the same manner as in Example 1 to obtain a printed wiring board of Comparative Example 1.

Comparative Example 2 D glass fiber yarn (DOE225110) was used for warp and weft, density diameter 62/'l 5 rl'Hn, weight 5
A plain woven fabric was woven with 4 wood/25 mm.

Next, prepreg was laminated in the same manner as in Example 1, and the printed wiring board of Comparative Example 2 was made. 0.

Comparative Example 3 Silica fiber yarn (8FG300110) was used for the warp and °^ yarns, density diameter 62 pieces/'l 5 mm, weft 54 pieces/
A plain woven fabric was woven at 25 mm.

Next, the prepreg was prepared by 'FsI F' in the same manner as in Example 1.
Then, a printed wiring board of Comparative Example 5 was obtained.

Next, according to an embodiment of the present invention? Table 1 shows the results of comparing the dielectric constant of the printed wiring board with a comparative example. Note that the dielectric constant was measured according to JIS 0-8481 method.

Table 1 As is clear from Table 1, the dielectric constant of the printed wiring board using the printed wiring board fabric according to the present invention is significantly improved compared to the comparative example.

(Effect of the invention)

Claims (1)

[Claims] (1) Printed wiring characterized by being made of a fabric woven from at least one type of fiber yarn selected from E glass fiber yarn, D glass fiber yarn, and silica fiber yarn, and polytetrafluoroethylene fiber yarn. Fabric for substrates.