JPS63236642A - Glass woven fabric-reinforced copper-clad laminated board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a glass woven reinforced copper-clad laminate for ultra-high frequencies, and particularly to one with improved dielectric properties.

[Prior Art] A Teflon copper-clad laminate, which has a dielectric Teflon substrate sandwiched with copper foil, is used in ultra-high frequency planar circuits such as microstrip lines. In order to prevent warping due to the difference in thermal expansion coefficients between the copper foil and the Teflon substrate and improve strength in the plane direction (direction along the plane), one to several layers are added to the Teflon substrate of this Teflon copper-clad laminate. Glass woven fabric is laminated and embedded.

However, the dielectric constant εg and dielectric dissipation tangent tan6g of glass are much larger than those of Teflon, as shown in Table 1 according to the Science Chronology, so the overall dielectric properties of glass woven fabric reinforced copper-clad laminates are poor. This will greatly influence the

Table 1 Dielectric properties of materials In particular, when the number of warp and weft yarns in a woven fabric differs, the dielectric properties differ in the direction of the grain of the glass woven fabric. - Examples are shown in Table 2.

In the past, glass silk cloth was laminated on a Teflon substrate without any consideration being given to the fact that the glass woven fabric greatly influences the overall dielectric properties and that the dielectric properties differ depending on the grain direction of the glass woven fabric. For this reason, I
The H1f characteristics were different.

By the way, in glass woven fabric-reinforced copper-clad laminates for ultra-high frequency planar circuits, the following problem arises when the dielectric properties, particularly the dielectric constant, vary depending on the grain direction of the glass woven fabric.

■ When forming a resonator, the dimensions of the resonator will differ depending on the grain direction, and if this is ignored, the resonant frequency of the resonator will deviate from the specifications and the performance of the device will not be achieved.

■ In order to make the dielectric properties the same, the width of the stripline must be varied in the grain direction, making the design complicated.

■ Since Teflon laminates are expensive, in order to make economical use of the limited board area, it is necessary that they not be placed in the grain direction.

[Problems to be solved by the invention] As mentioned above, in the conventional glass woven reinforced copper clad laminate,
Since dielectric properties differ depending on the grain direction of the glass woven fabric, the design of the planar circuit is complicated, and the expensive laminates cannot be used economically.

An object of the present invention is to provide a novel glass woven fabric-reinforced copper-clad laminate that eliminates the drawbacks of the prior art described above and can significantly increase design efficiency and economic efficiency.

Means for Solving Problem U] The glass woven fabric-reinforced copper-clad laminate of the present invention has copper foil stretched on the front and back sides of a Teflon substrate, and a reinforcing glass woven fabric inside the Teflon substrate to increase the thickness of the substrate. It has a sand inch structure with layers stacked in the horizontal direction.

The upper and lower glass woven fabrics are staggered and laminated so that the dielectric properties of the copper-clad laminate, which are dominated by the glass silk fabrics on the upper and lower laminated layers, are approximately equal in all directions in the plane of the copper-clad laminate. .

[Function] When the upper and lower glass woven fabrics are shifted, the number of laminated glass threads in the thickness direction and the laminated state change, and the dielectric properties of the copper-clad laminate change. Therefore, by appropriately adjusting the misalignment between the upper and lower glass silk cloths, the dielectric properties in the plane direction become approximately equal.

[Example] An example of the present invention will be described below based on FIGS. 1 and 2.

FIG. 1 shows an example of a glass woven fabric-reinforced copper-clad laminate of the present invention.

1 is a Teflon board which is a dielectric material, and copper foils 2, 2 which serve as a ground conductor and a planar circuit are stretched on the front and back sides of this board,
A copper-clad laminate 10 is constructed to be used in a microstrip type distributed constant circuit for ultra-high frequencies.

In the Teflon substrate 1 of this copper-clad laminate 10, there are warp threads 3.
A reinforcing glass woven fabric 5 made of weft threads 4 is laminated in the thickness direction of the substrate 1, and the following points are taken into consideration when combining the shapes 9 of the glass woven fabrics 5 that are laminated above and below. .

■ If the weave of the glass woven fabric is plain weave, twill weave, satin weave, etc., the warp and weft yarn count and number should be the same.

(2) Laminating a plurality of sheets of the above-mentioned woven fabric in the Teflon substrate 1;

Figure 1 shows three warp yarns with the same count and number of threads as shown in Figure 2. The glass fabric 5 is reinforced with a plain weave glass fabric 5 using weft threads 4, and the weave of the three glass fabrics 5 stacked one on top of the other is staggered.

The method of shifting is as follows.

Assuming that the glass woven fabric 5 shown in Fig. 2 is the upper layer, the middle layer glass woven fabric and the lower layer glass woven fabric form a rectangular upper layer with vertical and horizontal sides each having a length twice the yarn width. Weave 1
Fill in 1. The warp yarns 13 and weft yarns 14 of the intermediate layer are shifted by one yarn width in the X and Y directions with respect to the upper layer so that the intersection point 12 of the intermediate layer is located at the upper left corner of the texture 11 of the upper layer. Further, the warp yarns 23 and weft yarns 24 of the lower layer are shifted in the X and Y directions by two yarn widths so that the intersection point 15 of the lower layer is located at the lower right corner of the weave 11 of the upper layer.

When the upper and lower glass woven fabrics are shifted in this way, the number of threads in the thickness direction at any point and the number of yarns held are uniform across the surface direction, and the dielectric properties no longer depend on the surface direction.

As a result, when designing a planar circuit, there is no need to check or manage the planar direction, and there is no need to change the width of the microstrip line depending on the planar direction.

Furthermore, when forming a microstrip line type resonator, only one type of dimension is required for a single frequency.

Furthermore, it becomes easy to allocate an expensive Teflon copper-clad laminate for attaching a large number of stripline circuits.

In addition, in the above example, the counts of the warp and weft.

We have described the case of woven fabrics with the same number of yarns, but in the case of silk fabrics with different numbers of warp and weft yarns and different numbers of yarns, when layering, the weaving direction will not be biased toward one direction, but will be evenly distributed in all directions. By stacking them so that they face each other, differences in dielectric properties due to the direction of the grain can be eliminated. For example, when two such glass woven fabrics are laminated, the weaving directions are made perpendicular to each other, for example.

[Effects of the Invention] To summarize, according to the present invention, the dielectric characteristics in the planar direction are approximately equal, so there is no need to consider the planar direction, and the planar circuit can be easily designed. In addition, since it becomes easy to allocate planar circuits to the copper-clad laminate, the expensive Teflon copper-clad laminate can be used effectively, making it extremely economical.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a glass woven fabric-reinforced copper-clad laminate showing an embodiment of the present invention, and FIG. 2 is a plan view showing an example of the glass woven fabric used in FIG. 1. In the figure, 1 is a Teflon substrate, 2 is a copper foil, 3 is a warp, 4 is a weft, 5 is a glass woven fabric, 10 is a copper-clad laminate, and 11 is a texture.

Claims (3)

[Claims] (1) In a glass woven reinforced copper clad laminate in which copper foil is stretched on the front and back sides of a Teflon substrate, and a reinforcing glass woven fabric is laminated in the thickness direction of the substrate within the Teflon substrate, the top and bottom of the laminated It is characterized in that the upper and lower glass woven fabrics are stacked with an offset so that the dielectric properties of the copper-clad laminate, in which the glass woven fabric is dominant, are approximately equal in any direction along the surface of the copper-clad laminate. Glass woven reinforced copper clad laminate. (2) The glass woven fabric has warp and weft counts,
The laminate according to claim 1, characterized in that the glass woven fabrics have the same number of fibers, and the upper and lower laminated layers are stacked with the weave offset so as to fill the weave of the glass woven fabric. . (3) The above-mentioned glass woven fabric is characterized in that it is a glass woven fabric with different counts or numbers of warp and weft yarns, and the upper and lower layers are stacked with the weaving direction shifted orthogonally to each other. A laminate according to claim 1.