JP3323116B2 - Glass cloth - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in glass cloth used as a base material of a printed wiring board used in the electric and electronic fields.

[0002]

2. Description of the Related Art In general, printed wiring boards are manufactured by a known processing method of drilling holes, cleaning holes, electroless copper plating, etc. in a copper-clad laminate. Is generally known to change. The copper-clad laminate used here is manufactured by laminating and molding a prepreg obtained by impregnating a thermosetting resin such as an epoxy resin into a glass cloth with a press machine, and the glass cloth used for this is JIS R3414. Are generally used.

[0003] The glass cloth to be used is selected in consideration of the configuration of the laminated plate and the like in order to reduce the dimensional change, warpage, and twist of the laminated plate. It is not a fundamental solution,
A glass cloth having a new configuration is desired. For example, since the distance between the adjacent glass yarns constituting the glass cloth is large, a large amount of resin is distributed in the gap between the yarns in the prepreg, and there is a variation in the curing shrinkage of the resin. That the yarn is easy to move due to the large spacing between
Or variations in the dimensional change of the laminate due to poor balance due to differences in weaving density in the vertical direction and horizontal direction,
Further, there is a problem of anisotropy in the vertical and horizontal directions (hereinafter, anisotropic).

As the circuit pattern becomes denser as recently, advanced technology is required for correcting the scale factor required for producing a negative of the circuit pattern or for forming a through hole. In particular, when the size of the work of the printed wiring board is large, many parts positioning marks are required. On the other hand, an attempt to expand the yarn bundle by applying physical processing such as fiber opening to the glass cloth specified in the JIS standard, and to propose a glass cloth simply having the same weaving density in the vertical and horizontal directions However, none of them are sufficient and the problem has not been solved.

[0005]

SUMMARY OF THE INVENTION The present invention does not require advanced technology for the scale factor correction operation, and enables automatic insertion of components easily with a small number of component positioning marks. Provided is a glass cloth capable of reducing variation in dimensional change of a substrate during a process of forming a printed wiring board from a copper-clad laminate and reducing anisotropy particularly in a vertical direction and a horizontal direction. It is in.

[0006]

As a result of various studies on the above-mentioned problems, the present inventor has found that the structure of a plain woven glass cloth for a laminated board is (a) the area covered by glass thread within a specific range.
(B) Determine the spacing ratio between glass threads per thread width.
Teikashi, and a range a relationship between (c) the warp yarn or weft of weave density and weave shrinkage, weave (d) the warp yarn and the weft yarn
The shrinkage ratio is a specific relationship, and (e) the bulk density is within a certain range .
By doing so, in the laminated board using the glass cloth, (i) the amount of resin existing in the gap between the glass threads is reduced.
It allows, (ii) can optimize the balance of shrinkage woven with weaving the number of glass strands, (iii) to reduce variations in dimensional changes of the substrate during the manufacturing process, the dimensions of the laminated board
The present inventors have found that the variation in the change can be reduced, and (iv) the anisotropy of the warp yarn and the weft yarn can be reduced, and the anisotropy is remarkably improved . Thus, the present invention has been completed.

That is, the present invention provides a glass cloth having a plain weave structure having a thickness of 95 to 103 μm, which is woven from a glass yarn in which either or both the warp yarn and the weft yarn are yarns of 45 tex or less. Area covered by the glass yarn in the glass cloth plane ≧ 96% (1) (b) In the glass yarn constituting the glass cloth in both the vertical direction and the horizontal direction, the ratio of yarn interval / yarn width <30. %
··· (2) (However, the yarn yarn interval referred to here indicates the distance x shown in FIG. 1). (C) The weaving density of the warp yarn is CT, and the weaving density of the weft yarn is CY.
And when the weaving shrinkage of the warp yarn is DT and the weaving shrinkage of the weft is DY, (CT / CY) / (DT / DY) = 0.7 to 1.3 (3) ( d) When the weave shrinkage of the warp yarn is DT and the weave shrinkage of the weft is DY, DT> DY (4) (e) The bulk density of the glass cloth is 43.5 to 70%. A glass cloth is provided.

Hereinafter, the present invention will be described in detail. The glass cloth of the present invention refers to a glass cloth having a plain weave structure formed by weaving a glass yarn in which either or both of the warp yarn and the weft yarn are 45 tex or less. Furthermore,
The glass yarn constituting the glass cloth of the present invention is preferably a yarn designation E225 specified in JIS R3413.
Having a count equivalent to 1/0 and E225 1/0 yarns is preferred to obtain a cloth of about 100 μ (about 0.1 mm) thickness required for laminate construction. The count here indicates the mass of the glass thread per unit length as shown in JIS R3413. The term “equivalent” as used herein indicates yarns having the same or similar counts, for example, yarns such as E232 1/0 and D225 1/0. FIG. 1 is a schematic diagram specifically showing the distance between the yarns constituting the glass cloth of the present invention. x is the distance between the yarns.

Usually, the dimensional change of the laminated board is governed by how the glass cloth as the base material suppresses the volume change such as the curing shrinkage of the matrix resin, and the dimensional change is caused by the unevenness of the resin in the laminated board. Depends on the distribution. For example, in the glass cloth plane, it is most preferable that the entirety is covered with the glass thread. However, the area covered by the glass thread in the glass cloth plane ≧ 96% (1) Necessary for uniform distribution [ (a)
].

[0010] For that, there is a gap between the glass threads
It is more preferable that the vertical direction and the horizontal direction
Glass thread that constitutes glass clothAt  Yarn spacing / yarn width ratio <30% (2)(However, the yarn spacing referred to here means the distance x shown in FIG. 1
Show. ) Needs to be .The ratio of the yarn interval / yarn width is Less than 25%Like
New. [(b)]. Specifically, the average yarn width of the E225 1/0 yarn is 300
In the case of μm, the gap needs to be less than 90 μm.
Become.In addition,Measurement of glass thread width and gap between threads
Embed the cloth in cold-cured epoxy resin and polish it.
To cut out the glass thread cross section, electron microscope, optical microscope, etc.
Observed by measuring the yarn width and the length between the yarns.

Although the anisotropy largely depends on the amount of glass thread in the vertical and horizontal directions, it also depends on the magnitude of the reinforcing effect of the glass thread in the plane direction in each direction. In order to reduce the anisotropy, it is necessary to optimize the relationship between the weaving density and the weaving shrinkage of the yarn. That is, the weaving density of the warp yarn is CT, the weaving density of the weft yarn is CY , the weaving shrinkage ratio of the warp yarn is DT, and the weaving shrinkage ratio of the weft yarn is DY .
Sometimes , (CT / CY) / (DT / DY) = 0.7 to 1.3 (3), preferably 0.8 to 1.2. It is effective for improving the properties [ (c) ]. When the value of the above formula (3) is less than 0.7, the reinforcing effect in the horizontal direction is large, and when it exceeds 1.3, the reinforcing effect in the vertical direction is large, and the balance between the vertical and horizontal reinforcing effects is poor. . The weaving shrinkage was measured according to the weaving shrinkage measuring method described in JIS L1096.

In general, when a prepreg is prepared by impregnating a glass cloth with a thermosetting resin such as an epoxy resin, tension is applied in the vertical direction, and the cloth is elongated in the vertical direction. Therefore , the weaving shrinkage rate of the warp yarn is determined in advance by D
T, when the weft shrinkage of the weft is DY, it is necessary to use a glass cloth that satisfies the condition of DT> DY (4).
[(D) ]. In this case, it is varied fabric Ri shrinkage slightly during prepreg creation, vertical, balance of the reinforcing effect of the horizontal acts in the direction to be held, not to preferred dimensional changes behavior.

The glass thread used in the present invention is E
Using a glass yarn having a count equivalent to that of the yarns of 225 1/0 and E225 1/0, the weaving shrinkage of the warp yarn is made larger than the weaving shrinkage of the weft yarn (that is, the above DT> D).
Y ) Preferably, the warp yarn weave density is 65-71
The number is 25/25 mm , but it is more preferably 69 ± 2/25 mm in order to achieve the density regardless of the weaving density of the weft yarn. If it exceeds 71 threads / 25 mm, the yarns will rub against each other, causing problems such as fluff and the like, which is not preferable in quality. Further, the weft density of the weft yarn is preferably 53 to 65 yarns / 25 mm from the balance of the reinforcing effect. However, if the weave density of the weft yarn increases, the productivity of the fabric decreases, and further, fluff and the like are generated. 55 ± 2 / 25m
m is not more preferable.

It is expected that the reinforcing effect of the base material will be increased by increasing the amount of glass with a constant thickness, and the bulk density of the glass cloth must experimentally satisfy the following conditions.
You . The bulk density of the glass cloth is from 43.5 to 70% [(e)]. That is, the bulk density of the glass cloth 43.5% or more, that have been remarkably confirmed that the absolute value of the dimensional change is small in particular 44% or more. In this case, the bulk density of the glass cloth is good the greater for the purpose of lowering the dimensional change, the upper limit is 70% there is also the relationship of the gap forming glass yarns constituting the glass cloth. In addition ,
The bulk density of the cloth is [cloth cloth weight (g / m ² )
/ Glass density (2.6 g / cm ³ )] / (cloth thickness (mm) × 1000) × 100.

Further, by performing fiber opening processing, for example, fiber opening processing by pressure of columnar water flow, fiber opening processing by high frequency vibration in a solvent such as water, etc., the thickness is reduced and the bulk density is increased. , glass cloth of the present invention ing <br/> more preferable state. As a glass cloth of a laminated board used for a printed wiring board, a glass generally called E glass (alkali-free glass) is used. The effect of the present invention is not impaired.

The laminated board of the present invention may be prepared according to a conventional method. For example, the glass cloth of the present invention is impregnated with a matrix resin such as an epoxy resin to prepare a resin-impregnated prepreg, and one sheet of the prepreg is prepared. Or a plurality of sheets are laminated, or combined with a resin-impregnated prepreg made of ordinary glass cloth, and laminated under heating and pressure molding. When a glass cloth and a nonwoven fabric are used in combination as the base material, the object of the present invention can be achieved by using the glass cloth of the present invention for the surface layer. Also,
Even when the glass cloth of the present invention is used as an adhesive prepreg for molding a multilayer board, it is possible to achieve improvement in dimensional change behavior such as reduction in variation in dimensional change and improvement in anisotropy.

The resins used for the laminate include epoxy resins, unsaturated polyester resins, polyamide resins, and B resins.
Thermosetting resins such as T resin and cyanate resin, thermoplastic resins such as PPO resin, polyetherimide resin, and fluorine resin, or a mixed resin thereof are exemplified. Further, a resin in which an inorganic filler such as aluminum hydroxide is mixed in the resin may be used.

[0018]

The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the invention thereto. The laminate in the examples was prepared by the following method, and the dimensional change was J
It was measured according to IS6481. Table 2 shows the measurement results. (Production method of laminate): The glass cloth of the present invention was impregnated with an epoxy resin and dried to obtain a prepreg. One prepreg is laminated, and 35 μm copper foil is further laminated on top and bottom at 175 ° C. and 40 kg /
The laminate was obtained by heating and pressurizing at ² cm ² .

(Examples and Comparative Examples) ECE225 1/0 was used for the warp yarn, and E was used for the weft yarn.
Using CE225 1/0, with the fabric configuration shown in Table 1,
It was woven using an air-jet room with a plain weave structure.
The fiber opening process was performed by the water pressure of the columnar water flow. From the results in Table 2, it was found that when the glass cloth of the present invention was used, the dimensional change behavior, anisotropy, and variation of the laminate were significantly improved.

[0020]

[Table 1]

[0021]

[Table 2]

[0022]

The laminated board for a printed wiring board using the glass cloth of the present invention has a small dimensional change and its variation during molding and its anisotropy is smaller than that of the conventional one, so that the circuit pattern is small. Even in the case of high density, correction of the scale factor is not required, and the component can be positioned only by the reference hole by the component positioning mark.

[Brief description of the drawings]

FIG. 1 shows the distance between yarns constituting the glass cloth of the present invention .
FIG .

[Explanation of symbols] x: Distance between yarns

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-272135 (JP, A) JP-A-5-286065 (JP, A) JP-A-7-226571 (JP, A) JP-A-10-107 37038 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) D03D 1/00-27/18 H05K 1/03 B32B 1/00-35/00

Claims (1)

(57) [Claims] 1. A glass cloth having a plain weave structure with a thickness of 95 to 103 μm, wherein one or both of a warp yarn and a weft yarn is woven from a glass yarn having a length of 45 tex or less; (1) (b) In the glass yarns constituting the glass cloth in both the vertical direction and the horizontal direction, the ratio of yarn interval / yarn width <30% (2) (However, the yarn yarn interval referred to here indicates the distance x shown in FIG. 1.) (c) The weaving density of the warp yarn is CT, and the weaving density of the weft yarn is CY.
And when the weaving shrinkage of the warp yarn is DT and the weaving shrinkage of the weft is DY, (CT / CY) / (DT / DY) = 0.7 to 1.3 (3) ( d) When the weave shrinkage of the warp yarn is DT and the weave shrinkage of the weft is DY, DT> DY (4) (e) The bulk density of the glass cloth is 43.5 to 70%. Glass cloth characterized by the above.