JPS61193846A - Double-side metal lined plate for high-frequency circuit - 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] [Technical Field] The present invention relates to a space satellite broadcast receiving 7 antenna circuit board, a microscopy +7 tup super high frequency circuit board, a space satellite broadcast receiving converter circuit board, a circuit board for personal radio, etc. This invention relates to a double-sided metal clad plate for high frequency circuits used as circuit boards for high frequency applied equipment.

[Background technology] Conventionally known metal clad boards for high frequency circuits used as this type of high frequency printed circuit boards include glass base Teflon copper clad boards, glass base crosslinked polyethylene copper clad boards, and alumina ceramic boards. It is being However, although the alumina ceramic substrate has a dielectric loss (tan δ) of 10-4 level and excellent high frequency characteristics, the 50×5
The limit is about 0a+-, and large dimensions cannot be obtained, and there are significant restrictions on the use. *Tara board tear 0
Copper clad boards and glass substrate cross-linked polyethylene copper clad boards have the problem that dielectric loss increases due to the opening between the resin part interface and the glass fiber interface, tan δ increases, and high frequency transmission loss increases. However, there is also the problem that the materials cost is high and it is difficult to popularize it for consumer use. Further, in the above-mentioned polyethylene-based high-frequency circuit metal clad board, there was a problem in that the adhesiveness between the polyethylene and the metal foil forming the circuit was extremely poor, and the circuit was easily peeled off.

[Objective of the Invention J] The present invention has been made in view of the above points, and uses polyolefin as a dielectric layer to have low dielectric loss, excellent adhesion to metal foil, and can be formed at low cost. The object of the present invention is to provide a double-sided metal clad plate for high frequency circuits.

[Disclosure of the Invention J] However, the double-sided metal clad plate for high frequency circuits according to the present invention has layers 2 of modified polyolefin modified with unsaturated aliphatic carboxylic acids on the front and back surfaces of the layer 3 of non-polar polyolefin, respectively.
, 2, the metal foils 1, 1 are laminated and bonded together.The present invention will be described in detail below.

In the present invention, in order to reduce dielectric loss, a non-polar polymer is selected in terms of molecular structure as the resin for forming the dielectric layer, and ion conductive substances and impure polar groups in the molecule are reduced. , a resin with increased crystallinity is used, and a nonpolar polyolefin is used as such a resin.

This non-polar polyolefin includes high density polyethylene, medium density polyethylene, low density polyethylene,
Monoolefin polymers such as polypropylene, polypropylene, polybutene-1,4-methylpentene polymer, olefin copolymers such as ethylene-propylene copolymer, ethylene-propylene block copolymer, ethylene butene copolymer, and mixtures thereof, etc. Among them, it is preferable to use polyethylene, and non-polar polyolefins include 0
．． It is used as a film (sheet) with a thickness of about 5 to 2 m to produce double-sided metal clad plates for high frequency circuits.

Although this non-polar polyolefin has a small dielectric loss and is suitable as a dielectric layer, since it is non-polar, its adhesion to metal foil is extremely poor.Therefore, in the present invention, a modified polyolefin is used as an adhesive layer. Use. This modified polyolefin is obtained by modifying the polyolefin listed above (polyethylene is particularly preferred) with an unsaturated fatty acid carboxylic acid or its anhydride. Examples of unsaturated fatty acid carboxylic acids and their anhydrides include maleic acid, itaconic acid, citraconic acid, acrylic acid, maleic anhydride, itaconic anhydride, and citraconic anhydride, of which maleic anhydride is most preferred. The degree of modification is preferably set so that the content based on unsaturated aliphatic carboxylic acids and their anhydrides is about 3% by weight.
It is necessary to have 1 overlapping %. To give an example of modifying a polyolefin with p&water maleic acid, a modified polyolefin can be obtained by melt-kneading a mixture of maleic anhydride, polyolefin, and organic peroxide using an extruder.

Also, instead of organic peroxides, II-a%I[[
It can be obtained by reacting 0.1 to 10% by weight of an S metal compound selected from oxides and sulfates belonging to the 11% genus at a temperature equal to or higher than the melting point of the polyolefin. This modified polyolefin is used as a film with a thickness of about 30 to 200 microns to produce double-sided metal clad plates for high frequency circuits.

Further, as the metal foil, an electrically conductive body such as a foil of copper, aluminum, nickel, iron, or an alloy thereof having a thickness of 5 to 100 μm, or a printed thin film of metal paste can be used.

As shown in FIG. 2, the metal N1, the modified polyolefin film 6.1m, the modified polyolefin film 7, the modified polyolefin film 6, and the metal Wi1 are layered on top of this layer, and this is applied at a weight of about 2 to 20 kg/am''. 110
By heating and pressurizing for about 2 to 20 minutes at a temperature of ~170°C, the modified polyolefin layer 2 is added to the nonpolar polyolefin layer 3, which will become the dielectric layer 8 as shown in FIG.
, 2 as an adhesive layer and weld the metal foil 1.1 f/ftMf"
Thus, a double-sided metal clad plate for high frequency circuits can be obtained.

In addition to using modified polyolefin and non-polar polyolefin as the films 6 and 7, first, a composite polyolefin sheet having modified polyolefin layers on both sides of a non-polar polyolefin layer is prepared by co-extrusion method or sheet bonding method. make,
It is also possible to obtain a double-sided metal clad plate for high-frequency circuits by sandwiching this between two layers of metal M1゜1 and heating and pressurizing it in the same manner as above.In this way, it is possible to manufacture it continuously. This makes it possible to do the following. The double-sided metal clad plate for high frequency circuits obtained in this way has metal M1
By forming a printed circuit in a conventional manner by etching or the like, it can be used as a high frequency circuit board. At this time, a circuit is formed on only one of the pair of metal foils 1.1. In this way, the other metal foil 1 can be used as a ground electrode, and if a circuit is formed on each of the pair of metal foils 1.1, it can also be used as a double-sided circuit board.

In the double-sided metal clad plate for high frequency circuits obtained as described above, glass fiber is not used as a base material, and the dielectric layer 8 is composed of the non-polar polyolefin layer 3 with low dielectric loss. This makes it possible to create circuit boards with low dielectric loss and excellent electrical properties in high frequency bands, and the material cost is low because it is made of non-polar or modified polyolefin. This makes it possible to expand the range of 11!1ffl into consumer applications. The dielectric layer 3, which is made of non-polar polyolefin, is well adhered to the metal foil 1 by the layer 2 of polyolefin modified to have polarity, so that the circuit formed by the metal foil 1 does not peel off. Furthermore, this will eliminate that fear.

Next, the present invention will be explained in detail with reference to Examples.

A medium density polyethylene sheet with a thickness of 1-1 (Linear LO replacement-de) is used as a non-polar polyolefin film.
using polyethylene density 0.93 and melt index M, I = 4),
This was sandwiched between two 75μ thick ethylene-maleic man composite films (maleic anhydride content 1% by weight) as modified polyolefin films, and further 18
Two μ-thick #! This was sandwiched between whistles, laminated in a layered structure similar to that shown in Figure 2, and then heated at a temperature of 135℃ and a pressure of 2 to 5℃.
A double-sided metal clad plate for high frequency circuits was produced by holding the mixture for 2 to 3 minutes under the condition of ``Kg/am'' to integrate and further cooling.

The results of measuring various properties of the double-sided metal clad plate for high frequency circuits thus obtained are shown in the following table.

In the "Processing conditions" in the table below, rAJ remains in the accepting state.
As a result of the C-distilled water chart, it is not the one of the present invention! It was confirmed that the adhesive strength of the 1 foil was excellent, the dielectric constant and dielectric loss tangent were extremely small, and the high frequency characteristics were improved. In particular, the dielectric constant and dielectric loss tangent are shown in Figure 3 (a) (
As shown in b), it is confirmed that the material of the present invention is significantly superior to other materials. In FIG. 3, A shows a lath epoxy copper clad board, B shows a glass polyimide copper clad board, C shows a plastyeflon copper clad board, and D shows an example product of the present invention.

[Effect of the invention 1 As described above, in the present invention, metal foil is laminated and bonded to the front and back surfaces of a layer of non-polar polyolefin through layers of modified polyolefin modified with unsaturated aliphatic carbon RM, respectively. Therefore, it is possible to obtain a double-sided metal-clad plate for high-frequency circuits with excellent high-frequency characteristics by using a layer of non-polar polyolefin with low dielectric loss without using glass fiber as a base material. The non-polar polyolefin layer that serves as the dielectric layer is well bonded to the metal foil by the polar polyolefin layer, which allows the material to be manufactured at low cost. Therefore, there is no risk that the circuit made of metal foil will peel off.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an embodiment of the present invention, FIG. 2 is an exploded cross-sectional view of one of the manufacturing steps of the same, and FIG. 3(a) is a graph of dielectric constant and dielectric loss tangent. 1 is a metal foil, 2 is a modified polyolefin layer, and 3 is a nonpolar polyolefin layer.

Claims (3)

[Claims] (1) A double-sided metal clad plate for high frequency circuits, characterized in that metal foil is laminated and bonded to the front and back surfaces of a nonpolar polyolefin layer through layers of modified polyolefin modified with unsaturated aliphatic carboxylic acids, respectively. (2) The double-sided metal clad plate for high frequency circuits according to claim 1, wherein the nonpolar polyolefin is polyethylene. (3) The double-sided metal clad plate for high frequency circuits according to claim 1, wherein the unsaturated aliphatic carboxylic acid is maleic anhydride.