JP2001055642A - Cloth for resin reinforcement and laminated board using the same - Google Patents

Abstract

(57) [Summary] [Problem] To provide a resin reinforcing cloth capable of producing a laminated board with less warpage and good surface smoothness. SOLUTION: The arrangement of the tissue points on the front side and the arrangement of the tissue points on the back side of the weft double satin weave or the trans-double satin weave are arranged so as to be mirrored when viewed from each surface. In this way, a cloth that solves the problem was manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to aramid fiber cloth, carbon fiber cloth, glass cloth used for reinforcement of FRP or the like, or to printed wiring boards used for electronic equipment, electric equipment, computers, communication equipment and the like. Glass cloth.

[0002]

2. Description of the Related Art Glass fibers have excellent heat resistance, dimensional stability, electrical properties, etc., and are used for reinforcing resins, and are widely used in the electronics field. In particular, glass woven fabrics woven from glass yarns Is FR because of its excellent properties
There is much demand as P or a material for printed wiring boards.
These laminates are made by impregnating a base material such as a glass woven fabric with a thermosetting resin composition such as an epoxy resin, stacking a required number of prepregs in which the impregnated resin is in a semi-cured state, and furthermore, printed wiring. As a board for a board, a metal foil such as a copper foil is laminated on one or both sides as necessary, and then pressed,
It is manufactured by heating to cure the resin. recent years,
Mounting methods for automatically inserting components such as ICs into a printed wiring board are increasing. In order to automatically insert this part, the position of the pin hole needs to be accurate. However, in the heat press process of manufacturing a printed wiring board, warping occurs in the printed wiring board due to distortion inherent to the glass cloth, distortion due to weaving, or partial difference in curing of the resin due to heating. Further, the printed wiring board is exposed to severe conditions in which high-temperature heating and cooling are repeated, accompanied by heating such as drying and fusing of the solder resist. For this reason, since the dimensional change is different in each process and the warp of the printed wiring board is different, correction may be required every time the process is changed at the time of positioning.

One of the causes of warpage and dimensional change is, for example, a plain woven glass cloth, in which both the warp and the weft are up and down and intersect, so that a yarn longer than the width or length of the cloth must be used. It is considered that there is weave shrinkage, and the unevenness of this weave shrinkage affects the warpage, twist, and dimensional stability of the laminate. As a method of reducing the shrinkage of the weave, a glass cloth having a high weave density or a method disclosed in
As in JP-A-92543, there is an example in which the number of weft yarns is larger than the number of warp yarns. Or,
A method has also been considered in which the weaving method is a twill weave, a satin weave, or the like to reduce the number of texture points (intersecting points, weave) of the yarn constituting the cloth.

Further, the thickness of the copper foil for forming a circuit by arranging it on the surface of the laminated board is as thin as 5 to 10 μm, and as the circuit becomes finer, the width is reduced to 50 to 80 μm. I have. Therefore, it is also desired to improve the smoothness of the surface of the laminate and the adhesion to the copper foil. Therefore, as a method for simultaneously improving the dimensional stability and the surface smoothness, there is disclosed a method such as Japanese Patent No. 188892 in which glass fibers constituting a glass cloth are opened by a high-pressure columnar water jet. However, even in such a method, the above-mentioned problem still remains, and further improvement has been desired. Also, in the field of FRP reinforcement materials, carbon fiber reinforcement materials used for aircraft materials that require high strength are desired to have as few bends as possible in fiber bundles constituting the materials. A reinforcing material is used, but when a cloth is used, an 8-sheet satin cloth is often used. However, the satin weave has a small number of texture points in the fabric, so the cloth is too flexible and it is difficult to handle,
Further, the cloth may have a front and a back, and the molded product may warp in a specific direction.

[0005]

An object of the present invention is to reduce the warpage and to improve the surface smoothness and the yield of products such as printed wiring boards at the same time. Conventionally, for this purpose, attempts have been made to reduce the weaving texture and improve the smoothness by reducing the texture points of the warp and weft yarns by using a twill or satin cloth. However, twill weave is a structure in which the warp and weft yarns are adjacent to each other and have a diagonal line where the design points run diagonally.Distortion in the printed wiring board tends to concentrate along the design points, causing warpage torsion. Cheap. Also, the satin weave
Since the combination of warp and weft is arranged at regular intervals without being continuous, there are no drawbacks such as twill weave,
Since there is a front and a back, what is formed on the printed wiring board has a difference in distortion between the front and the back of the cloth, and tends to appear as a warp twist. In an application that dislikes warping and twisting, such as a printed wiring board, in order to minimize them, a prepreg laminated on a prepreg when a laminate is manufactured using a prepreg using a satin weave cloth is placed on a flat surface by 90%. It is necessary to rotate the film again and turn it upside down to stack it upside down. This is troublesome and error-prone, and is not practical in the actual manufacturing process of a laminated board.

[0006]

Means for Solving the Problems The present inventors have reduced the amount of warp and weft crossing and bending by reducing the number of texture points at the intersection of the warp and weft of the reinforcing fiber cloth, and have obtained a resin-reinforced molded product. As a result of studying to reduce the dimensional change rate of conventional plain-woven glass cloth, reduce the warpage and twist, improve the surface smoothness of the molded product, and make a glass cloth with good handleability, the conventional satin weave These problems have been solved by improving. In the satin weave, warp and weft yarns are sparsely dispersed in a certain rule without being continuous. As a result, the structure point is surrounded by the surrounding yarn, which has a good effect on the improvement of the smoothness of the laminate.

In the present invention, the conventional satin weave is composed of one type of warp and two types of weft, a surface weft consisting of a front weft and a warp, and a double weft made of a back weft composed of a back weft and a warp. Reinforcement for FRP with less warp, good dimensional stability and improved surface smoothness by weaving or reverse double satin weave and the same arrangement of the front and back weaves It has been successfully used as a cloth or a glass cloth for a printed wiring board. The same arrangement of the front and back weaves of the weft double satin weave or the warp double satin weave of the present invention is as follows. The arrangement of the tissue points on the front surface of the satin weave cloth and the arrangement of the tissue points on the back surface viewed from the front side are the same. In other words, the tissue points on the front and back sides have been appropriately translated vertically, horizontally or diagonally,
That is, the tissue points on the surface of each other are reflected in the mirror. The top and bottom texture points arranged in this way do not overlap the top and bottom texture points, but may be adjacent or spaced apart. When adjacent to each other, the laminated plate is likely to be slightly thin at its texture point, and therefore it is preferable that the texture points on the front surface and the back surface are separated from each other by one or more stitches.

In the present invention, satin weaving reduces the intersection of warp and weft yarns, reduces the amount of shrinkage of warp and weft yarns, and weaves the front and back of the cloth as weft or warp double satin weave. And eliminates the front and back of the cloth, which are the drawbacks of the simple satin weave, with less warpage of the laminate, good dimensional stability, and excellent surface smoothness. For the warp or weft double satin weave cloth of the present invention, ordinary reinforcing fibers such as glass fiber, carbon fiber, and aramid fiber can be used.
Can be used for P. The reinforcing fiber constituting the present invention may be any fiber which can weave the above-mentioned commonly used cloth, and is not a special material.

As the glass fibers constituting the glass cloth, glass fibers such as E glass, S glass and D glass which have been conventionally used as a reinforcing material for a glass fiber reinforced resin laminate can be used. The yarn for glass cloth composed of these glass fibers is not special. The diameter of the filament is 3-25 μm,
More preferably, a single yarn of 5-9 μm is preferred. The thickness of the yarn is the number of gr per 1000 m T
Expressed as EX, the range of usable TEX is 2.5-200 TEX with no difference between warp and weft,
Preferably, 5-150 TEX is widely used as a substrate for printed wiring boards. If it is less than 2.5 Tex, the yarn is too weak and there is a problem in production, and 200 Tex
There is no inconvenience even if x or more is used, and it can be manufactured if necessary. However, those having a thickness of this degree or more are rarely used because they have little use.

The number of twists of the glass fiber yarn is preferably a single-twisted single yarn from the viewpoints of resin impregnation, fiber opening properties of glass cloth by post-treatment, and the like. In terms of a numerical value, it is preferably 0-2.0 times / 25 mm, more preferably 1.0 times / 25 mm or less, including zero of completely twisted. On the other hand, when the number of twists is 2.0 or more, since the yarn is a single twist yarn, workability during weaving is deteriorated. In double weft weaving or warp double weaving using this glass fiber yarn, the number of warp yarns and weft yarns to be driven, the weight per unit area of the cloth, the combination of the TEX of the warp yarns and the weft yarns to be used, and the cross warp yarns The weight ratio per unit area of the weft yarn and the like are determined by experiments or experience according to the required performance and quality such as the handleability of the cloth and the surface smoothness of the formed laminate.

[0011] The warp or weft double satin woven glass cloth woven to satisfy the above conditions is subjected to the same processing as the processing of the glass cloth for producing a normal prepreg. For example, a prepreg can be prepared by removing the sizing agent attached to the surface of the glass fiber by heating and deoiling, treating the surface with a silane coupling agent, impregnating a resin varnish, and heating and drying. . Further, in order to increase the resin impregnation speed and improve the surface smoothness, a fiber opening treatment using a known water flow may be performed.

When the product of the present invention is used, various known surface treatments can be performed, and a known silane coupling agent is mainly used as appropriate. For example, a silane coupling agent is usually used as an aqueous solution, a solution of an organic solvent such as alcohols, ketones, glycols, ethers, and dimethylformamide, or a solution of a mixed solvent of water and these organic solvents in an amount of 0.1 to 5%. Used at a concentration of% by weight. The amount (solid basis) of the silane coupling agent adhered to the surface of the glass fiber is 0.01-
1.5% by weight. In the case of a sizing agent that does not need to be removed by heat deoiling, such treatment may not be performed. As the resin for prepreg, epoxy resin,
A known thermosetting resin such as a phenol resin, an unsaturated polyester resin, and a polyimide resin can be used. Among them, epoxy resins are preferred. When impregnating the glass cloth with the resin, it is preferable to set the amount of the resin in the prepreg to be in the range of 50 to 80% by weight of the prepreg single weight.

[0013] The double satin weave glass cloth is composed of three layers of front weft yarn, warp yarn and back weft yarn, and the warp double satin weave glass cloth is the reverse of the above and has no front and back. The laminates made are not warped or twisted. In order to produce a laminated board using this prepreg, a required number of prepregs are laminated, and if necessary, a metal foil is laminated on the outside of the prepreg, and the laminate is formed by heating and pressing. When stacking multiple sheets,
When the stack is rotated 90 °, 90 ° and 90 ° with respect to the warp, the resulting laminate has a warp / weft weight ratio of 1 to eliminate anisotropy in dimensional stability and disperse distortion due to weaving. , Warpage and twist can be further reduced.

[0014]

As described above, since the structure of the front and back texture points (intersecting points, texture points) is the same as that of the warp or weft double satin weave, the advantage of the simple satin weave cloth is excellent. In addition to dimensional stability and surface smoothness, the double satin weave has the following additional advantages. The same applies to the warp double satin weave. 1. Since the front and back of the cloth have disappeared, the lamination unit must be at least 1
It is possible to produce a fiber-reinforced resin plate with a small warpage and twist, and a good surface smoothness. In the case of simple satin weave, a minimum of two layers are required to minimize warpage and twist, and the number of fiber layers is four. The cloth of the present invention is such that the fiber layer has a surface weft, a warp, and a back weft. With three layers, one layer can be reduced. 2. Since the cloth has no front and back, there is no difference in the amount of resin impregnation between the front and back of the prepreg, and warpage and twisting are reduced. 3. Since it has a three-layer structure of a front weft yarn, a warp yarn and a back weft yarn, misalignment and bending are unlikely to occur, and it is easier to handle than a plain satin weave cloth.

[0015]

Next, the present invention will be described based on embodiments. <Example 1> Using a glass fiber yarn of ECG751 / 01Z for the warp and ECG371 / 01Z for the weft, the number of the warp is 43/25 mm, and the number of the weft is 80/25 mm. The design points were arranged with a jump number of 2, and the design points on the back were translated so that the reference points were the third warp yarns from the reference points in the table and, when viewed from the front side, had the same arrangement as in the table. An E glass cloth with a weft double of 9 satin weave (number of flights: 2) having a unit weight of 432 g / m2 was obtained. After heating and deoiling the glass cloth, the acetic acid was removed.
It was immersed in a treatment liquid in which 0.5 wt% of γ-methacryloxypropyltrimethoxysilane was dissolved in distilled water containing 1 wt%, squeezed with a mangle so that the pickup amount became 30%, and dried at 110 ° C. for 5 minutes. Then, the glass cloth was impregnated with an epoxy resin varnish shown in the separate table, and then heated and dried at 150 ° C. for 5 minutes to remove the solvent to obtain a prepreg having a resin amount of 65% by weight and a melt viscosity of 300 poise. Next, using only one layer of this prepreg,
8μm copper foil is superimposed, temperature 170 ℃, pressure 30kg /
Heat and pressure molding under the molding conditions of cm2, time 70 minutes,
A glass epoxy double-sided copper-clad laminate was obtained. Various tests were conducted and the results are shown in Table 1.

Comparative Example 1 44 warp yarns / 25 m using glass fiber yarn of ECG75 1/0 1Z
m, weft 32.5 yarns / 25mm, single weight 208g / m2
A glass epoxy double-sided copper-clad laminate was obtained in the same manner as in Example 1 except that two plain weave cloths were used. Various tests were performed and the results are shown in Table 1.

<Comparative Example 2> ECG75 1/0 was applied to the warp yarn.
1G, using ECG37 1/0 1Z glass fiber yarn for the weft, the number of warp yarns is 43/25 mm, and the number of weft yarns is 40/25 mm.
9-sheet satin weave (single weight: 332 g / m2)
E glass cloth was obtained. A glass-epoxy double-sided copper-clad laminate was obtained in the same manner as in Example 1, except that two prepregs using this woven fabric were laminated with their surfaces facing upward.

Epoxy resin varnish composition table Epicoat 1001 (manufactured by Yuka Shell Epoxy) 80 parts by weight Epicoat 154 (manufactured by Yuka Shell Epoxy) 20 parts by weight Dicyandiamide 4 parts by weight Benzyldimethylamine 0.2 part by weight Parts dimethylformamide 30 parts by weight

[0019]

[Table 1]

1. Test method 1-1. Measurement of dimensional change rate The press-formed copper foil-clad laminate was heated in a 170 ° C. hot air dryer for 30 minutes, cooled to room temperature, and the length of the laminate was measured. , Before heating. 1-2, Surface smoothness measurement method The surface smoothness was measured using the double-sided copper foil-clad laminates prepared in Example 1, Comparative Examples 1 and 2 as samples. The measured value is the value of MAX. Measurement method: JIS B0601 “Surface roughness measurement method”
10 points on each dotted line in the 100 cm 2 sample surface (60 points in total), the length of one point was 10 mm, and a universal shape measuring machine (manufactured by Kosaka Laboratory Co., Ltd., trade name: SEF-1)
Measured using A). 1-3. Measurement method of warpage A test piece cut into a size of 150 mm x 150 mm on a flat surface plate is placed on a surface plate, and a 500 gr weight is placed on the center of one side. JIS B gap between surface plate
Measure to 0.1 mm with a Class A straightedge specified in 7514.

[Brief description of the drawings]

FIG. 1 is an example of a surface arrangement of organization points of a weft double nine satin weave (fly count 2)

FIG. 2 is an example of a back surface arrangement of organization points of a weft double 9 satin weave (number of flight 2) in FIG.

[Explanation of symbols]

 ×: The position of the texture point on the surface of the table. ：: The position of the texture point on the back surface. Δ: The position of the texture point on the back surface viewed from the front surface.

Claims (2)

[Claims] 1. A resin reinforcing material characterized in that the arrangement of the texture points on the surface of the weft double satin weave cloth or the warp double satin weave cloth and the arrangement of the texture points on the back surface as viewed from the front side are the same. cross. 2. A laminate for a printed wiring board, wherein the material constituting the resin reinforcing cloth is glass fiber.