JPH01249333A - Glass cloth for laminate, and laminate - Google Patents

Abstract

PURPOSE:To obtain the glass cloth having excellent impregnation property for resin and less strain existing in its inside by using untwisted glass thread having a specified weight per unit length for at least one of warps and wefts. CONSTITUTION:In the glass cloth used for the laminate utilized as the base plate of a printed wiring board, etc., at least one of the warp and weft constituting the glass cloth, is caused to be the untwisted glass thread with the weight of 2.5-240g/1,000m. The untwisted glass threads are many bundled threads without twisting glass filament. In the concrete, molten glasses are quickly drawn out from a plurality of nozzles of a bushing, and they are coated with a sizing agent. After said threads have been bundled together, they are wound on a paper or plastic tube by a winder. Thus obtained glass fiber bundle, e.g. a strand is used. The untwisted glass thread may be used for any one of the warp and weft or for both of the warp and weft. In the weaving machine weaving the glass cloth by using the untwisted glass thread, an air jet weaving machine is preferable from the points of the quality of the glass cloth having been woven and its productivity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laminate suitable for use as a substrate for printed wiring boards and the like, and a glass cloth used for the laminate.

[Conventional technology]

Conventionally, printed wiring for electronic devices has been made by using glass cloth as a base material, impregnating it with thermosetting resin such as EPO resin, and forming it by stacking several to ten or more sheets and hot pressing. It is often used as a board.

The glass cloth used in such a laminate is manufactured as follows. That is, first, the glass raw material melted in the spinning furnace is guided to an electrically heated part called a bushing that has 50 to 2,000 nozzles on the bottom, and the molten glass is drawn out at high speed from the bottom nozzles to form glass fibers. let These fibers are lightly sprayed with water and passed through the applicator.

A sizing agent is applied to protect, lubricate, and bundle the fibers.Then, a gathering shoe forms a fiber bundle called a strand. The number of single glass fibers constituting the fiber bundle is adjusted as necessary, and may be divided into several small strands. The strand is continuously wound onto a zigzag or plastic knit nib attached to a rotating cylinder that rotates at high speed, while being twilled at a small angle so that it can be easily unwound in the subsequent process.
Form a cake. To produce glass cloth, strands are drawn from the resulting cake, heated to form heated yarn, and the heated yarn is used for weaving.

A ring twister is usually used as a device for heating the strands. The strands are drawn horizontally from the cake fed to the creel so as not to damage the fibers.
The material is supplied to a roller by rotation of the feed roller or creel itself, and is wound onto a bobbin fixed to a spindle that rotates at high speed while being heated. Since it is wound on a bobbin that rotates at high speed, it is usually 4 to 8 kg per bobbin, so it is not possible to wind it in large quantities.

The twisted yarn produced in this way has approximately 400 to 4,000 warps aligned in a warping process and is wound around a warp beam. At this time, 5. In order to protect the warp threads from wear during weaving, a secondary size (mainly poval or starch type) is attached to the warp threads. Next, in the weaving process, a warp beam is attached to the loom, and the same twisted yarns are used as wefts to weave glass cloth. Most of the glass cloth currently used for printed wiring boards is plain-woven.

Air jet looms are used for weaving. Sizing agents and other substances are attached to the glass cloth as it is woven, and if adhesion with the resin becomes a problem, heat treatment is used to remove organic substances attached to the glass fibers (this process is called deoiling). .

Glass cloth that has had its surface deposits removed by de-oiling.

The surface is treated with a camping agent that matches the resin used as the matrix, and then impregnated with an epoxy resin or the like, and several to several sheets are stacked and hot pressed to form a laminate.

[Problem to be solved by the invention]

However, the glass cloth for laminated plates woven in the above manner has twists in the warp and weft.

The cross sections of the warp and weft threads are arranged in a circular shape and do not become very flat. 5 When impregnating glass cloth with resin, it takes time to impregnate the heated yarns that make up the glass cloth with resin, resulting in poor productivity. However, there was a problem in that air bubbles remained in the finished laminate, degrading the quality of the laminate.

In addition, in this glass cloth, the warp and weft are not flat, so there are gaps between the warp and the weft, and the fabric as a whole has areas with and without glass fibers. exists. Therefore, a laminate using this material has a poor surface roughness, which causes the drill to bend when using a small diameter drill during drilling, and causes hole wall roughness when using a 4I semi-diameter drill.

Further, in conventional laminates using glass cloth, there is a problem in that the thin laminates are warped or twisted due to the twisting of the heating yarns constituting the glass cloth.

In recent years, in the field of printed wiring boards, which is the main application of laminates, the requirements for the performance of printed wiring boards have become more stringent due to advances in high-density automatic mounting technology, and the above problems have become increasingly important. .

Various proposals have been made to solve these problems. For example, as a method to distribute glass fibers as much as possible throughout the glass cloth and to improve resin impregnation into the glass cloth, after weaving the glass cloth, the heated yarns that make up the glass cloth are treated by mechanical means. It has been proposed to loosen the fiber bundle and create gaps between the fibers by doing this (see, for example, Japanese Patent Laid-Open No. 156945/1982 and Japanese Patent Laid-open No. 194252/1982).

However, this method has a production drawback in that it requires an extra processing step on the glass cloth. Additionally, the heating yarns that make up traditional glass cloth.

Generally, the twist is 0.7 to 5 times/25 m*, and after weaving into cloth, the warp and weft bind each other, so each fiber bundle becomes loose and takes << 8 hours for mechanical processing. Even after treatment, the fiber bundles do not loosen sufficiently. In particular, it is difficult to loosen the fiber bundle at the contact area between the warp and the weft, and there is also the drawback that impregnation cannot be sufficiently improved.

6 It is known that the twisting of the yarns that make up the glass cloth causes warping and twisting of the laminate. 5 In order to prevent the effects of this twisting, we have created a glass cloth that combines left-twist and right-twist yarns. It has been proposed that by making a laminate using this glass cloth, the twisting moments of the threads can be canceled out to each other and the occurrence of warpage can be prevented (
For example, Utility Model Application Publication No. 54-55958, Utility Model Application Publication No. 61-
(See Publication No. 22160).

However, in order to use a combination of left-handed and right-twisted yarns, it is necessary to arrange the warp yarns with different twist directions in a predetermined order to cancel out the twisting moment during the warping process in which a large number of warp yarns are wound onto a beam. , which had the disadvantage of requiring a great deal of attention and effort. Also.

Even if cloth is manufactured by arranging left-twisted and right-twisted yarns in the warp and weft to cancel out the twisting moment of the yarn, in recent air jet looms for weaving glass cloth for laminates, one end of the warp row The weft thread is blown from one end to the other by an air jet, and when the thread reaches the other end, it is cut on the driving side.

The process of hammering it in again is repeated to make it into cloth.

The weft threads are not folded back like they are woven on a shirttle loom, but are free at both ends, making it easier for the threads to untwist. The twist of the inserted weft is suppressed by the warp, but as it gets closer to both ends, the suppression becomes weaker.For example, at the center, the twist is 1 turn/25 III, but at the ends, it is 0.6 twist, 725 yarn weight. Sometimes. This drawback could not be avoided using conventional methods.

This invention solves the drawbacks of conventional glass cloth for laminated plates.

In other words, it is a glass cloth that eliminates poor resin impregnation, uneven distribution of glass fibers within the glass cloth, and distortion of the glass cloth that causes warping and twisting of the laminate when it is made into a thin laminate. and to provide a laminate made using the same.

(Means for Solving the Problem) As a result of various studies, the present inventors found that the impregnating property of the resin is good;
In order to obtain glass fabrics with less inherent distortion, it is much more effective to use yarns that are not already twisted than to weave heated yarns into glass fabrics and then loosen the yarns; We have discovered that it is possible to weave glass cloth even with yarns without .

Conventionally, as mentioned above, N temporary glass cloth is woven from twisted yarns. In the early days, the Shattle loom was used to weave glass cloth.

In this Shirttle loom, the glass thread wound in the Shirttle was easily damaged (untwisted, the yarn was likely to split and become fluffed, so it was not possible to produce a good product, so heated yarn was inevitably used). Due to this historical background, in the glass fiber industry, even though various looms such as air-jet looms, two-toe looms, and water jet looms have been developed, it is still considered impossible to weave untwisted glass fibers. It has become common knowledge to use heated yarn.In the past, rovings were formed by bundling a plurality of strands together.

Roving cloth for FRP uses non-twisted glass fiber roving for both the warp and weft, but this roving cloth is usually woven using a rapier loom, and has a small number of warp and weft yarns and large irregularities. Roving cloth such as There was no idea of weaving the glass cloth of the plate using untwisted yarn.

However, as a result of experiments conducted by the present inventors, the air jet M machine has been found to be effective, perhaps due to recent improvements in the quality of glass fibers, improvements in the quality of sizing agents, and improvements in loom performance.

They discovered that weaving using untwisted glass yarn was possible, and after various studies, they completed the present invention.

The present invention has been made based on this knowledge.9 The first invention of the present application uses untwisted glass yarn of 2.5 to 240 g/1000 m as at least one of the warp and weft constituting the glass cloth. The gist is glass cloth for 1ffl product.

5 The second invention of the present application is a laminate made of a glass cloth as a base material, impregnated with a resin and cured, wherein at least the IJi glass cloth has 2 warp threads constituting the glass cloth as described above, At least one of the weft threads.

2.5 to 240 g/1000m (D-free FW crow thread (!: Shik) The gist is a laminate characterized by using glass cloth for laminates.

The untwisted glass thread used in the present invention is made by bundling a large number of glass filaments without twisting them.

Specifically, molten glass is rapidly drawn out from multiple nozzles in a bushing, sizing agent is applied, and after convergence, a glass fiber bundle or strand (conventional glass cloth) is wound onto two paper or plastic tubes using a winder. (before the twisting step) can be used in manufacturing the constituent heating yarns. A cake made by winding a strand on a plastic tube can be warped in a conventional manner after drying the sizing agent applied to the glass fibers, and then wound around a beam to form a warp. It can also be used as a weft. Note that when using this strand as a weft yarn, it is not necessarily necessary to dry the sizing agent; instead, a glass yarn drying device is installed before entering the yarn guide of the loom, and the strand is continuously passed through this drying device. By using it while
Can be dried.

In the present invention, the untwisted glass yarn may be used for either the warp or the weft, or for both. When this untwisted glass yarn is used only for the weft and heating yarn is used for the warp, the heating yarn for the warp is:

Although it is possible to create a product that achieves the desired purpose by using products with the same twist direction, use products that are warped so that the twist directions are a mixture of left-handed and right-handed twists. This cancels out the twisting moment of the warp yarns, resulting in an even better glass cloth for laminated plates.

Those that use untwisted glass for both the warp and weft.

Since the tightness between the glass fibers is loose and easy to unravel, the resin impregnation property is improved, and since the untwisted glass thread has no twisting moment, the laminate does not warp or twist due to twisting of the threads.

Various known sizing agents can be used for this untwisted glass yarn, depending on the purpose of the glass cloth, drying equipment, drying temperature, etc., but in particular, the recently developed sizing agent that does not require the degreasing process 9 surface treatment process can be used. Sizing When a sizing agent is used, a mechanical process, a degreasing process, a surface treatment process, and the like are not necessary, and economical advantages such as productivity improvement and yield improvement are further increased.

Any known loom can be used for weaving glass cloth using untwisted glass threads, as long as it does not cause major damage to the untwisted glass threads and can weave the desired fine-mesh glass cloth.1 For example: , air jet loom, water jet loom, shuttle loom, rapier loom, etc. can be used. Among these, air jet looms are preferred from the viewpoint of quality and productivity of woven glass cloth. In the air jet m machine,
When untwisted glass yarn is used as a weft, there is less frictional force against the weft, and therefore less damage is caused to the untwisted glass yarn. Moreover, the advantages of high weaving speed and high productivity can be obtained.

Regarding the count of the untwisted glass yarn used in the present invention, if it is too thin, productivity will decrease, which is undesirable, and if it is too thick, the woven glass cloth will become coarse and the quality of the laminate will deteriorate. Moreover, it comes apart during weaving, making it difficult to weave. Considering these points, the count of untwisted glass yarn is usually 1,
It was selected as 2.5-240g/1000m.

Preferably, one having a weight of 5.6 to 135 g/1000 m is used.

Function: The glass cloth of the present invention uses untwisted glass threads at least for the warp or weft. This untwisted glass yarn itself is not tightened by twisting, so it is easily deformed by external force when weaving it into glass cloth. It now exists in the city in scattered forms. Therefore, resin impregnation properties are good. When impregnating glass cloth with resin, the contact surface between the warp and weft is the most difficult part to impregnate with resin because the resin passes through the warp or weft.

In the present invention, since at least one of the warp and weft is an untwisted glass yarn, the contact surface of the warp and weft can be quickly impregnated with the resin via the untwisted glass yarn, which is easy to impregnate.

The resin impregnation rate is much faster than traditional glass fabrics in which both the warp and weft are made of heated yarns.

In addition, in the glass cloth of the present invention, since the untwisted glass threads are flat, the gaps between the warp yarns or the weft yarns in the inner part become smaller, and the glass fibers are distributed throughout the inner part.

The area without glass fibers becomes extremely small. For this reason.

The glass fiber moves less easily in the city, making it less likely that the fabric will shift during handling, making it an easy-to-handle fabric. Furthermore.

A laminate using such a glass cloth with small openings has a small surface roughness and is excellent in drilling workability.

Incidentally, this method has been conventionally applied to the glass cloth of the present invention as well. It is possible to perform mechanical processing to loosen the warp and weft threads, and the same effect can be achieved in a shorter time and with less processing than conventional methods. Therefore.

It does not damage the glass fibers and does not lose the original strength of the glass cloth.

Furthermore, since the glass cloth of the present invention uses non-twisted glass yarn for at least one of the warp and weft, there is little influence from twisting of the warp or weft (therefore, the laminate using this glass cloth has 9 warps). , less twisting.

In the present invention, untwisted glass yarn was used for the glass cloth, but
The use of untwisted glass provides the following advantages in terms of production quality.

Conventionally, when producing heated yarn from glass strands, the glass strands produced in a glass spinning machine and made into a cake are unwound from the cake, passed through a traveler that rotates around the bobbin at high speed in order to apply Twisting is winding onto a bobbin! Although the threading process is being carried out, the filament breaks when passing through the traveler, causing fuzz. However, since untwisted glass thread does not have this kind of winding or overhanging, the filament does not break.2 Therefore, the woven fabric has less fuzz, and r! The process of applying A is 67.5g/
For yarn with yarn count of looOm, 0.5-1kg/H
With a production volume of r, it is customary to wind 3 to 8 kg on one bobbin. Therefore, the twisting process requires a large number of twisting machines and personnel. In comparison, the untwisted glass yarn used in the present invention does not require such a process, and therefore has extremely high productivity.

Further, the untwisted glass thread used in the present invention is essentially a strand before twisting, and the winding amount can be 20 kg or more per cake. In this way, by being able to wind up a large amount at once, the following advantages can be obtained in manufacturing glass cloth.

The glass cloth used for printed wiring boards has a problem because if the thread joints enter the glass cloth, that part becomes bulky and when press-molding the printed wiring board, it can damage the copper foil and cause one circuit to break. Must not be. For this reason, automatic switching of weft threads, which is used in the production of synthetic fiber textiles, is not possible, and the loom automatically stops when the threads run out. Currently, the weft supply involves replacing the bobbin manually, resetting it from the beginning, and restarting the process, which is a tedious process. The glass weft that is normally used is wound around 4 to 8 kg on one bobbin, and the cake of the present invention can be wound around 2 to 5 times more than that amount, drastically reducing the number of thread splices and stopping the loom. It becomes possible to shorten the time.

〔Example〕

The present invention will be explained below with reference to Examples.

Example! The molten glass was drawn out at high speed from a fitting with a 200-hole nozzle opening to form glass fibers with a diameter of 7 μm, and passed through an applicator for the purpose of protecting and focusing the glass fibers. Apply R powder yarn sizing agent and form one strand with a gathering shoe.

While twilling the strands with wine goo, make a diameter of 200mm.
12kgt on 1 Oboro Gium tube! It was made into a strand cake. This cake was placed in a dryer and dried at 105°C for 20 hours. The strand thus produced, that is, the untwisted glass thread, was used as the weft for weaving. The warp threads are made of 200 filaments with a diameter of 7 μm, the same as the weft threads.

After applying the same sizing agent, the yarn was twisted to the left at a ratio of 1 turn/25 twists while being rewound once, and was wound around a bobbin as a normal heated yarn. After 1M, it was wound around a beam to form a warp. The number of stitches and other weaving conditions are as shown in Table-1.

During weaving, a non-twisted glass yarn cake for weft was set in a weft supply device installed near an air jet loom.

After passing the untwisted glass thread from the cake through a yarn guide,
The length of the untwisted glass yarn was measured, stored in a pool pipe for 1 hour, and then the untwisted glass yarn was driven into the warp opening by air injection from a nozzle to form a fabric. After this fabric is subjected to the same degreasing and surface treatment as glass cloth used as a normal resin composite material,
Physical property tests were conducted. The results are shown in Table-2.

Example ■ T-molten glass was pulled out from a bushing with 800 holes, 9 μm glass fiber was produced, and the strand was twilled onto a 300-diameter gi tube in the same manner as in Example I, and wound to 16 kg in a non-twisted state. I took it.

The wound cake is placed in a weft supply device installed near the air jet loom without drying, and the untwisted glass yarn is pulled out from the cake and continuously passed through a high frequency hot air dryer installed in front of the yarn guide. While drying the yarn, it was passed through a yarn guide and fed to a loom.

As the warp yarns, left-twist and right-twist yarns shown in Table 2-1 were warped so that these yarns were arranged alternately. After the woven glass cloth was deoiled and surface treated with epoxy silane, its physical properties were measured. The results are shown in Table-2.

Example ■ Example ■ except that a 400-hole bushing was used
In the same manner as above, 16 kg of the strand was wound in a non-twisted state onto a paper tube having a diameter of 186 am while being twisted.

This gelatin is heated to 50℃ using a vacuum low temperature and high frequency drying machine.

After drying for 12 hours, the fabric was used as weft and warp yarns to make glass cloth. This glass cloth was treated in the same manner as in Example 2, and then its physical properties were measured. The results are shown in Table-2.

Comparative example■ Count used for the warp in Example 1: 22.5g/1000m
, the number of twists is 1 twist/25mm, and the twist direction is left-handed yarn as the warp.

The material was used as a weft to weave a glass cloth, and the glass cloth was treated in the same manner as in Example I, and then its physical properties were measured. The results are shown in Table-2.

Comparative Example■ The strands wound in Example ■ were twisted in the usual manner to form a yarn with a yarn count of 67.5 g/l, 000m,
A glass cloth was woven using left-twisted yarns of 1 twist per 25 m as the warp and weft, and the glass cloth was treated in the same manner as in Example 2, and then its physical properties were measured. The results are shown in Table-2.

Example■ Using the glass cloth described in Examples ① and ① above.

A printed wiring board was molded.

The epoxy resin used to produce the sample of the printed wiring board had the following composition.

Epicoat 1001 (epoxy resin manufactured by Shell Chemical Co., Ltd.) 100 parts by weight Dicyandiamide 2 Benzyldimethylamine 0.2) Contents
100 〃
The glass cloth was impregnated with this epoxy resin varnish and dried to obtain a prepreg. 8 sheets of this prepreg were stacked together at a pressure of 50 kg/c+J and a temperature of 170°C.
Pressed with a holding time of 90 minutes, 1.1 mPJ,
A 450×450 dragon laminate was obtained.

Regarding this laminate, warping and torsion were measured using the test method specified in JIS, C, 6481, 5, 4°3. The results are shown in Table-3.

Comparative Example ■ Using the glass cloth described in Comparative Example ■, a laminate was molded under the same conditions as in Example ■, and warpage and twist were measured in the same manner.

The results are shown in Table-3.

As is clear from Table 2, the glass cloth of Example 1 of the present invention has excellent resin impregnation properties. Furthermore, as is clear from Table 5-3, the laminate using the glass cloth according to the embodiment of the present invention has less warpage and less twist.

Table 2 Air permeability: Based on JIS, t, 1096r air permeability test method A.

Resin impregnation: Drop 50 cc of epoxy resin face onto a 1QXIQcm woven fabric and measure the time until it is completely impregnated.

Table-3 Measurement method for warpage and twist: JLs, c, 6481
．． 5.4.3 Compliant sample dimensions: 450 x 450 mm Heating conditions
Heating at =170°C for 30 minutes [Effects of the Invention] As explained above, the glass cloth of the present invention has at least one of the warp and weft that constitute the glass cloth.

Since the glass cloth for laminates is made of untwisted glass yarn of 2.5 to 240 g/1000 m, the untwisted glass yarn in the city is spread out in a flat and loose state, and has excellent resin impregnation properties. For this reason, productivity is good when forming a laminated N temporary using this glass cloth, and a high-quality laminate without bubbles inside can be manufactured. Furthermore, when manufacturing the glass cloth itself, by using untwisted glass yarn, the heating process can be simplified and productivity can be improved compared to when conventional heating yarns are used.

In addition, this glass cloth has few gaps in which there are no glass fibers (in other words, it is in a closed state), so the laminate of the present invention formed using this glass cloth has only one surface. It has good roughness and excellent drilling workability.Furthermore, since there are few heated yarns in the glass cloth, there are few warps and twists that occur due to twisting.Thus, the laminate of the present invention It has good characteristics as a printed wiring board, and can be processed as a printed wiring board using high-density automatic mounting equipment.

Agent Patent Attorney Kyozo Matsu

Claims (2)

[Claims] (1) A glass cloth for a laminate in which at least one of the warp and weft constituting the glass cloth is an untwisted glass yarn of 2.5 to 240 g/1000 m. (2) A laminate made of a glass cloth as a base material, impregnated with a resin and cured, wherein the glass cloth according to claim 1 is used as at least one layer of the glass cloth. Characteristic laminate board.