JP2001348757A - Glass cloth and printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain both a glass cloth capable of exhibiting high heat resistance, high hygroscopic resistance and high impregnating properties of a printed wiring board and the printed wiring board comprising the glass cloth as a reinforcing material. SOLUTION: This glass cloth is characterized in that at least either one of a warp yarn and a weft yarn satisfies formula (1): (A+Bc)×C/25000>=0.95 [wherein, the woven fabric density of the yarns is C (yarns/25 mm) the yarn bundle cross-sectional width is A (μm); and the yarn bundle cross-sectional thickness intersecting the yarns at right angles is Bc (μm)] indicating an oriented state without substantial gaps, >=45% of the whole gap volume Vt is composed of >=5 μm gap diameter in the gap volume V (cm3/g) based on the unit weight of the glass cloth and the opening processing of the glass cloth arranged without the substantial gaps in the glass cloth composed of the warp yarn and weft yarn is carried out with a high-pressure water stream. The wiring board comprises the glass cloth as a substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a glass cloth and a printed wiring board using the same. In particular, it relates to an improved printed wiring board used in the field of electronics and electricity.

[0002]

2. Description of the Related Art A printed wiring board, particularly a multilayer printed wiring board, is formed by laminating a plurality of insulating substrates provided with conductor layers in a multilayer shape and joining them. The conductor layer provided on each insulating base material is electrically connected to an arbitrary conductor layer in the vertical direction through conductive holes called through holes, inner via holes, and blind via holes. Since these holes are processed by a drill or a laser, glass cloth used as a base material is flattened, and glass cloth with improved workability has been used. On the other hand, in the process of processing printed wiring boards, the use of lead-free solder is expected to increase due to environmental considerations.However, since lead-free solder generally has a high melting point, blisters and measling are used in heating processes such as reflow. Is likely to occur.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a glass cloth which exhibits high heat resistance, moisture absorption resistance and high impregnation of a printed wiring board, and a printed wiring board using this glass cloth as a reinforcing material. It is intended to be.

[0004]

Means for Solving the Problems As a result of diligent studies on the above-mentioned problems, the present inventors focused on the woven structure of glass cloth, and focused on a portion called a basket hole, which is surrounded by warp and weft, without glass thread. Reduce and
Expanding the gap between the single fibers of the glass yarn bundle,
At least one of the warp yarn and the weft yarn constituting the glass cloth is arranged substantially without a gap, and the gap volume and the gap diameter required by the mercury intrusion method are set to a specific area or more, so that the conventional glass cloth can be used. The inventors have found that a laminate having excellent heat resistance, moisture absorption resistance, and impregnation properties can be obtained as compared with the laminate used as the base material, and have reached the present invention.

That is, the present invention provides a glass cloth composed of a warp and a weft, which satisfies the following expression (1), which indicates that at least one of the warp and the weft is arranged substantially without gaps. And the gap volume V (cm ³ / g) per unit weight of the glass cloth is 45% of the total gap volume Vt.
% Or more with a gap diameter of 5 μm or more, wherein (A + Bc) × C / 25000 ≧ 0.95 (1) (Book / 25 mm), the cross-sectional width of the yarn bundle is A (μm), and the cross-sectional thickness of the yarn bundle orthogonal to the yarn is Bc.
(Μm). In a glass cloth composed of a warp and a weft, at least one of the warp and the weft is substantially equal to a glass cloth arranged with no gap.
The glass cloth according to the above, wherein the fiber cloth is subjected to fiber opening by a high-pressure water flow, or the printed wiring board, wherein the glass cloth described above is used as a base material.

Hereinafter, the present invention will be described in detail. (I) Features of Glass Cloth A glass cloth generally has a plain weave structure in which warp yarns and weft yarns alternately float and sink. In this case, a portion where the yarns overlap and one of the yarns is present. There are three types of states: a part called a basket hole and a part without glass thread surrounded by warp and weft. In order to obtain a printed wiring board excellent in hole processing and a printed wiring board with low moisture absorption in the thickness direction, it is important to reduce the number of basket holes of glass cloth in the insulating base material. Therefore, it is necessary that at least one of the warp yarn and the weft yarn constituting the glass cloth be arranged without any gap.

However, in order to make the fabric uniform,
When the shapes of the warp and the weft are approached, the warp and the weft alternately float and sink, so that the interval between the one yarn is affected by the thickness of the yarn bundle orthogonal to the yarn. Therefore, in order to minimize the distance between the yarns, the woven fabric density of one yarn is C (book / 25 mm), the cross-sectional width of the yarn bundle is A (μm), and the cross-sectional thickness of the yarn bundle orthogonal to the yarn is Bc ( μm), the state in which there is substantially no gap is a state defined by the following equation (1). (A + Bc) × C / 25000 ≧ 0.95 (1) Preferably, 1.12 ≧ (A + Bc) × C / 25000
Satisfy the relationship of ≧ 1.00. That is, (A
If + Bc) × C is smaller than 25 (mm) which is the unit length of the weaving density of the glass cloth, the interval between the yarns is wide,
It is not enough to prevent moisture absorption and affects the heat resistance during the moisture absorption test. Further, the distribution of the glass fibers in the plane direction becomes non-uniform, and the hole workability is reduced.

FIG. 1 is a schematic diagram for explaining the relationship between glass threads constituting a glass cloth. In FIG. 1, A is
The yarn bundle cross-section width of the warp or the weft is indicated, and Bc is
The yarn bundle cross-sectional thickness of a yarn orthogonal to the yarn is shown. In addition, in order to enhance the impregnation with the resin and improve the heat resistance, it is important to increase the space between the single fibers of the glass thread bundle and to enlarge the space where the impregnation of the resin is easy as much as possible. . That is,
Clearance volume V per unit weight of glass cloth (cm ³ /
g) is required to constitute 45% or more of the total gap volume Vt with a gap diameter of 5 μm or more, preferably 50% or more.
% Or more is desirably constituted by a gap diameter of 5 μm or more. The smaller the diameter of the single fiber of the glass thread constituting the glass cloth, the easier it is to disperse and the hole processing is easy. In other words, a thickness equal to or less than the nominal diameter E in JIS-R-3413, preferably a single fiber diameter equal to or less than the nominal diameter D is suitable.

(Ii) Production of Glass Cloth In order to obtain a glass cloth in which at least one of the warp yarn and the weft yarn of the present invention is arranged with substantially no gap, flattening of the glass cloth is performed, for example, by using a fluid. By applying pressure alone, processing by high-frequency vibration using a liquid medium, pressurization by jetting a fluid having a surface pressure, pressurization by a roll, etc., singly or in combination, the yarn width is increased, Can be narrowed. Preferably, the greige before the deoiling step is processed by a high-pressure water flow. Since the greige is provided with an organic binder called a sizing agent or sizing agent to protect the glass fiber, surface pressure processing is performed by high-pressure water flow before the deoiling process such as washing or heating to remove the binder. By applying, the damage of the glass fiber at the time of processing can be suppressed, and since the binder has an action and an effect as a lubricant, the binder can be flattened after the processing after the deoiling step.

On the other hand, when surface treatment is performed with a treatment solution containing a silane coupling agent, the glass fibers adhere to each other,
Since the gap between the glass fibers becomes small, it is necessary to open the fiber with a high-pressure water flow after the surface treatment to widen the gap between the glass fibers. The above-mentioned glass cloth of the present invention can be obtained by subjecting a glass cloth, in which at least one of a warp yarn and a weft yarn is arranged substantially without a gap, to fiber opening by a high-pressure water flow. In addition, the number of twists of the glass yarn used in the glass cloth of the present invention may be a commonly used number of twists. Preferably, the number of twists of the glass yarn is 0.7 or less, more preferably 0
By setting it to 0.3 times / inch, the yarn width becomes easier to spread. Further, by using the low twist yarn, the yarn is flattened, the cross-sectional shape of the yarn itself approaches the shape of a flat plate from an elliptical shape, and the distribution of the glass fibers in the glass cloth becomes more uniform.

(Iii) Composition and treatment of glass A glass generally called E glass is used for a glass cloth of a laminated board used for a printed wiring board and the like. D glass, S glass, high dielectric constant glass and the like are used. May be used.
The effect of the present invention is not impaired by the composition of the glass. Similarly, a glass cloth of a laminated board used for a printed wiring board or the like is usually subjected to a surface treatment with a treatment solution containing a silane coupling agent. If necessary, an acid, a dye, a pigment, a surfactant and the like may be added. The effects of the present invention are not impaired by the surface treatment.

(Iv) Production of Laminated Board The printed wiring board of the present invention may be prepared by a conventional method. For example, a resin impregnated prepreg is prepared by impregnating a glass cloth with a matrix resin such as an epoxy resin. Or by laminating a plurality of them, or by laminating a plurality or one of them on the inner layer core plate, and applying heat and pressure, and repeating these steps.
As the resin used for the printed wiring board, a thermosetting resin such as an epoxy resin, an unsaturated polyester resin, a polyimide resin, a BT resin, a cyanate resin, a PPO resin,
Examples thereof include thermoplastic resins such as polyetherimide resins and fluororesins, and mixed resins thereof. Also,
A resin in which an inorganic filler such as aluminum hydroxide is mixed in the resin may be used.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. The physical properties of the glass cloth, the cross-sectional width of the yarn bundle of the glass cloth, the gap diameter and the gap volume in the examples and the comparative examples, the method of preparing a laminated board using the glass cloth, and the test method were measured by the following methods. (1) Method for measuring physical properties of glass cloth Measured according to JIS-R-3420. (2) Method of measuring the cross-section width of warp and weft yarns A glass cloth is embedded with cold-cured epoxy, polished to cut the cross-section of the glass yarn bundles, and the warp yarns and the weft yarns are each photographed with an electron microscope. Then, the width of the cross section of the yarn bundle was measured.

(3) Method of Measuring Gap Volume of Glass Cloth Gap volume was measured using a mercury intrusion porosimeter at a measurement pressure of 1 to 2000 atm and a gap diameter of 13 μm to 7 nm. (4) Method for Producing Laminated Board for Printed Wiring Board A glass cloth was impregnated with a resin varnish and dried to obtain a prepreg. Six prepregs are stacked, and one
A copper foil having a thickness of 2 μm is superimposed and placed at 175 ° C., 40 kgf / cm ²
To obtain a laminate. (5) Method of measuring water absorption of laminate The copper was removed from the double-sided copper-clad laminate prepared by the method described in (4) above by etching, cut into 5 cm square test pieces, and immersed in boiling water. The amount of water absorption was measured from the weight change before and after immersion. In the table, D-n denotes a test piece in boiling water.
This indicates that the sample was immersed for a period of time to absorb moisture.

(6) Evaluation method of heat resistance of laminate The copper was removed from the double-sided copper-clad laminate prepared by the method described in (4) by etching, cut into 5 cm square test pieces, and heated at 121 ° C. After absorbing moisture in a saturated pressure cooker, the test piece was immersed in a solder bath at 290 ° C. for 20 seconds to check for blisters. PCT-n in the table is 1
This shows that the test piece was allowed to absorb moisture in a saturated pressure cooker at 21 ° C. for n hours. ：: extremely good, ：: good, Δ: normal, ×: bad (7) Resin impregnation The state of impregnation of the glass cloth with the resin varnish was observed visually and with an optical microscope, and the impregnation was evaluated. ：: extremely good, ：: good, Δ: normal, ×: bad As for the evaluation results of the above (5) to (7), examples and comparative examples of fabrics having the same yarn type were compared.

[0016]

Example 1 As a glass cloth, E225 1/0 1.0Z was used for warp and weft, and in an air jet loom, 60 warps / 25 mm and 58 wefts / 25 were used.
A glass cloth was woven with a woven fabric density of mm, and the obtained greige was subjected to processing by high-pressure water spray. Thereafter, high-temperature desizing was performed at 400 ° C. for 24 hours. Subsequently, as a surface treatment, a silane coupling agent, SZ6032 (manufactured by Dow Corning Toray Co., Ltd .: trade name), was used as a treatment liquid, a glass cloth was immersed, squeezed, and dried at 120 ° C. for 1 minute. Further, the glass cloth of Example 1 having a weight of 104 g / m ² was obtained by processing with high-pressure water flow. Using this glass cloth, evaluation was performed by the method described above.

[0017]

Example 2 As a glass cloth, D450 1/0 1.0Z was used for the warp and weft, and 60 warps / 25 mm and 47 wefts / 25 were used in an air jet loom.
A glass cloth was woven with a woven fabric density of mm, and the obtained greige was subjected to processing by high-pressure water spray. Thereafter, high-temperature desizing was performed at 400 ° C. for 24 hours. Subsequently, a surface treatment was performed using SZ6032 (manufactured by Dow Corning Toray Co., Ltd.), which is a silane coupling agent, as a surface treatment, a glass cloth was immersed, squeezed, dried at 120 ° C. for 1 minute, and further pressurized. The glass cloth of Example 2 having a weight of 48 g / m ² was obtained by processing with a water stream. Using this glass cloth, evaluation was performed by the method described above.

[0018]

Example 3 As a glass cloth, D450 1/0 1.0Z was used for the warp and weft, and in an air jet loom, 60 warps / 25 mm and 60 wefts / 25 were used.
A glass cloth was woven with a woven fabric density of mm, and the obtained greige was subjected to processing by high-pressure water spray. Thereafter, high-temperature desizing was performed at 400 ° C. for 24 hours. Subsequently, a surface treatment was performed using SZ6032 (manufactured by Dow Corning Toray Co., Ltd.), which is a silane coupling agent, as a surface treatment, a glass cloth was immersed, squeezed, dried at 120 ° C. for 1 minute, and further pressurized. The glass cloth of Example 3 having a weight of 54 g / m ² was obtained by processing with a water stream. Using this glass cloth, evaluation was performed by the method described above.

[0019]

Example 4 As a glass cloth, D450 1/0 0.3Z was used for warp and weft, and in an air jet loom, 60 warps / 25 mm and 60 wefts / 25 were used.
A glass cloth was woven with a woven fabric density of mm, and the obtained greige was subjected to processing by high-pressure water spray. Thereafter, high-temperature desizing was performed at 400 ° C. for 24 hours. Subsequently, a surface treatment was performed using SZ6032 (manufactured by Dow Corning Toray Co., Ltd.), which is a silane coupling agent, as a surface treatment, a glass cloth was immersed, squeezed, dried at 120 ° C. for 1 minute, and further pressurized. The glass cloth of Example 4 having a weight of 54 g / m ² was obtained by processing with a water stream. Using this glass cloth, evaluation was performed by the method described above.

[0020]

[Comparative Example 1] As a glass cloth, E225 1/0 1.0Z was used for warp and weft, and in an air jet loom, 60 warps / 25 mm and 58 wefts / 25 were used.
Glass cloth was woven at a fabric density of mm. Then 4
High-temperature desizing was performed at 00 ° C. for 24 hours. Subsequently, a surface treatment was performed using SZ6032 (manufactured by Dow Corning Toray Co., Ltd.), which is a silane coupling agent, as a treatment liquid. A glass cloth was immersed, squeezed, dried at 120 ° C. for 1 minute, and weighed 104 g. / M ² of Comparative Example 1 was obtained. Using this glass cloth, evaluation was performed by the method described above.

[0021]

[Comparative Example 2] E225 1 / 1.0 1.0Z was used for the warp and weft as glass cloth, and 60 warps / 25 mm and 58 wefts / 25 were used in an air jet loom.
A glass cloth was woven with a woven fabric density of mm, and the obtained greige was subjected to processing by high-pressure water spray. Thereafter, high-temperature desizing was performed at 400 ° C. for 24 hours. Subsequently, a surface treatment was performed using SZ6032 (manufactured by Dow Corning Toray Co., Ltd.), which is a silane coupling agent, as a treatment liquid. A glass cloth was immersed, squeezed, dried at 120 ° C. for 1 minute, and weighed 104 g.
/ M ² of the glass cloth of Comparative Example 2. Using this glass cloth, evaluation was performed by the method described above.

[0022]

Comparative Example 3 As a glass cloth, D450 1 / 1.0 1.0Z was used for the warp and the weft, and in an air jet loom, 60 warps / 25 mm and 47 wefts / 25 were used.
A glass cloth was woven with a woven fabric density of mm, and the obtained greige was subjected to processing by high-pressure water spray. Thereafter, high-temperature desizing was performed at 400 ° C. for 24 hours. Subsequently, a surface treatment was performed using SZ6032 (manufactured by Dow Corning Toray Co., Ltd.), which is a silane coupling agent, as a treatment liquid. A glass cloth was immersed, squeezed, dried at 120 ° C. for 1 minute, and weighed 48 g. /
Thus, a glass cloth of Comparative Example 3 having m ² was obtained. Using this glass cloth, evaluation was performed by the method described above.

[0023]

[Comparative Example 4] D450 1 / 1.0 1.0Z was used for the warp and weft as glass cloth, and in an air jet loom, 60 warps / 25 mm and 60 wefts / 25.
A glass cloth was woven with a woven fabric density of mm, and the obtained greige was subjected to processing by high-pressure water spray. Thereafter, high-temperature desizing was performed at 400 ° C. for 24 hours. Subsequently, a surface treatment was performed using SZ6032 (manufactured by Dow Corning Toray Co., Ltd.), which is a silane coupling agent, as a treatment liquid. A glass cloth was immersed, squeezed, dried at 120 ° C. for 1 minute, and weighed 48 g. /
Thus, a glass cloth of Comparative Example 4 having m ² was obtained. Using this glass cloth, evaluation was performed by the method described above.

[0024]

[Comparative Example 5] D450 1 / 1.0 1.0Z was used for the warp and weft as glass cloth, and 60 warps / 25 mm and 60 wefts / 25 were used in an air jet loom.
A glass cloth was woven with a woven fabric density of mm, and the obtained greige was subjected to processing by high-pressure water spray. Thereafter, high-temperature desizing was performed at 400 ° C. for 24 hours. Subsequently, a surface treatment was performed using SZ6032 (manufactured by Dow Corning Toray Co., Ltd.), which is a silane coupling agent, as a treatment liquid. A glass cloth was immersed, squeezed, dried at 120 ° C. for 1 minute, and weighed 54 g. /
Thus, a glass cloth of Comparative Example 5 having m ² was obtained. Using this glass cloth, evaluation was performed by the method described above.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

The use of the glass cloth of the present invention makes it possible to improve the impregnation during resin coating. Furthermore, by using the printed wiring board of the present invention, it is possible to provide a printed wiring board with reduced water absorption, excellent heat resistance, and good hole workability.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a relationship between glass threads constituting a glass cloth.

[Explanation of symbols]

 A Width of cross section of warp or weft yarn bundle Bc Thickness of cross section of yarn bundle orthogonal to the yarn

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yoshinobu Gondo 397-4 Kawatacho Shimogae, Moriyama-shi, Shiga F-term in Asahi Schwebel Co., Ltd. (Reference) 3B154 AA13 AB20 AB27 BA60 BB02 BE04 BF06 BF10 BF11 DA06 DA30 4L048 AA03 AB07 AB27 BA02 CA15 DA43 EA01 EB00

Claims (3)

[Claims] In a glass cloth comprising a warp yarn and a weft yarn, at least one of the warp yarn and the weft yarn satisfies the following formula (1), which indicates a state where the warp yarn and the weft yarn are arranged substantially without gaps. A glass cloth characterized in that a gap volume per unit weight of the glass cloth (cm ³ / g) is at least 45% of the total gap volume Vt with a gap diameter of 5 μm or more. (A + Bc) × C / 25000 ≧ 0.95 (1) [where the yarn fabric density is C (book / 25 mm), the yarn bundle cross-sectional width is A (μm), and the yarn bundle is orthogonal to the yarn. Section thickness Bc
(Μm). ] 2. A glass cloth comprising a warp yarn and a weft yarn, wherein at least one of the warp yarn and the weft yarn is subjected to fiber opening by a high-pressure water flow on a glass cloth arranged substantially without gaps. The glass cloth according to claim 1, wherein: 3. A printed wiring board using the glass cloth according to claim 1 as a substrate.