JP2002305373A - High-frequency circuit board or antenna substrate, and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit board or antenna substrate, together with manufacturing methods of them, which can be used in a high-frequency band about 0.5-30 GHz. SOLUTION: The surfaces, of two metal base materials, roughened to Ra0.1-20 μm are jointed directly, or through an anodic oxide coating, to both, upper and lower, surfaces of a dielectrics layer of a fluoro polymer. Thus a dielectrics substrate is provided where a metal layer is provided on both surfaces, with a physical bonding strength 1 kg/cm or higher between the metal layer and the dielectrics layer. The single surface or both surfaces of the metal layer are etched to form a circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency circuit board or an antenna board used for a high-frequency communication device, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, the amount of information communication has been increasing.
Communication in the higher frequency area has become popular,
There is a need for a circuit board and an antenna board that can be used in a high frequency range.

[0003] As a circuit board that can be used in a high frequency region, a dielectric material of a perfluorinated polymer is directly formed on a surface of a metal substrate having a surface roughness of Ra 0.1 μm or more and 20 μm or less. Providing a vapor deposited layer of metal on the opposite side of the metal substrate of the dielectric layer of the perfluorinated polymer having a layer formed thereon;
A circuit board on which a circuit is formed by etching (metallized wiring) has been proposed.

[0004]

The above circuit board is formed by combining a perfluorinated polymer with a metal substrate.
The thickness of the dielectric layer can be sufficiently reduced to 0.1 mm or less. As a result, while maintaining the impedance at a predetermined value, it is possible to use a metal vapor deposition layer to reduce the thickness of the circuit to increase the wiring density. It has excellent features such that it can be used practically even with a thin circuit of 0.1 mm or less. However, in general, it is difficult to metallize the surface of the dielectric layer with a fluorine resin by vapor deposition or the like, and it takes a lot of trouble such as performing a tetra-etch or using a special adhesive. In addition, there is anxiety about the circuit part due to use in severe environments such as temperature and humidity cycles. There is no need to increase the density of the circuit up to a thin circuit of 0.1 mm or less, but it can be manufactured more easily and can be used in the high frequency range of about 0.5 to 30 GHz. There are many demands for circuit boards and antenna boards that can be used safely even in harsh environments.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned requirements, and provides a circuit board or an antenna board which can be used in a high frequency range of about 0.5 to 30 GHz, and a method of manufacturing the same. Things. The feature is that on both upper and lower surfaces of the dielectric layer of perfluorinated polymer,
The two metal bases are joined to each other with the surface roughened to a surface roughness of Ra 0.1 μm or more and 20 μm or less, directly or via an anodic oxide film, to form a metal layer on both surfaces. A dielectric substrate having an adhesive force of 1 kg / cm or more due to physical adhesive force between the metal layer and the dielectric layer, and forming a circuit by etching the one or both metal layers. A high-frequency circuit board or an antenna board, and a method of manufacturing the same.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION As the dielectric layer of the perfluorinated polymer of the present invention, any one of PTFE, PFA, FEP, a mixture of any ratio thereof, or a laminate can be used. it can. The thickness of the dielectric is not particularly limited.
0.1 to 1.5 m when used at a frequency of about 0 GHz
m is preferred. Further, glass fibers can be blended in the perfluorinated polymer for the purpose of mechanical reinforcement and suppression of thermal expansion.

The metal used for the metal layers formed on the upper and lower surfaces of the dielectric layer of the perfluorinated polymer is aluminum,
Any metal such as copper, stainless steel, nickel and the like can be used, but aluminum is preferred from the viewpoint of conductivity, workability, and formability of the surface roughened by etching.

[0008] Roughening and / or anodizing of the metal substrate is necessary from the viewpoint of adhesion to the perfluorinated polymer. The degree of surface roughening is required to be Ra 0.1 μm or more, and the larger the degree, the better the adhesion due to the anchor effect is achieved. However, when Ra is 20 μm or more, transmission loss increases. Therefore, it is necessary to roughen the surface in the range of Ra 0.1 to 20 μm. The surface is preferably roughened in a range of 0.5 to 5.0 μm, more preferably 1.0 to 3.0 μm. As a means for roughening, any one of blasting, mechanical polishing, chemical etching, electrochemical etching or a combination thereof can be used. It is preferable to use it inside. Of course, it is not possible to form a through hole in the metal substrate by roughening. Therefore, the metal substrate needs to have a sufficient thickness to such an extent that a through hole cannot be formed due to the roughening. When a circuit is formed only on one side of the two metal layers on both sides, the thickness of the metal layer on the side on which no circuit is formed is 0.1 mm or more in terms of strength, and further, 0.5 to 2 mm. It is preferred that On the other hand, the metal layer on the circuit forming side forms a circuit by etching. Therefore, it is preferable that the metal layer be as thin as possible within a range where a through hole cannot be formed due to the above-described roughening. Preferably, 100
μm or less, more preferably 70 μm or less.

The anodic oxidation treatment is a treatment in which a metal substrate is immersed in a strong acid to oxidize the surface of the metal substrate. When the metal substrate is aluminum, it is called an alumite treatment. Alumite sulfate, alumite phosphate, and oxalate alumite are used. and so on.
In addition, by performing the anodic oxidation treatment after the surface roughening treatment, the adhesiveness between the metal substrate and the perfluorinated polymer can be further improved.

The method for forming the metal layers on both sides of the dielectric layer of the perfluorinated polymer can be a conventional method of bonding the perfluorinated polymer layer and the metal layer, and is not particularly limited. For example, directly on a roughened metal surface, or
A sheet of perfluorinated polymer may be joined by hot pressing or film lamination through an anodized surface, directly on the roughened metal surface, or through the anodized surface, John is coated and sintered by spin coating, spray coating, roll coating, screen printing, pad printing, ink jet, powder electrostatic coating, wet electrostatic coating, etc., and this coated surface or In between, a sheet of perfluorinated polymer may be sandwiched and joined by hot pressing or film lamination.

The formation of a circuit on a dielectric substrate having a metal layer on both sides can be performed by a known method, that is, by dissolving etching after masking the circuit portion. Circuits may be formed on both sides, circuits may be formed on one side,
Moreover, you may laminate | stack and use it in multiple layers.

[0012]

EXAMPLE As the two metal substrates, the thicker one was a 1.2 mm thick aluminum alloy plate (AB manufactured by Kobe Steel, Ltd.).
S material) and a thinner aluminum alloy foil (ABS material manufactured by Kobe Steel) having a thickness of 60 μm was prepared. The surfaces of these metal substrates were electrochemically etched in a 7 wt% NH ₄ Cl aqueous solution with an amount of electricity of 23 coulombs / cm ² , and further subjected to anodizing treatment to form an alumite layer.

(Example 1) Two metal bases were sandwiched by sandwiching a 0.5 mm thick PTFE sheet from both sides with the alumite layer facing inward, and joined by hot pressing. A metal substrate was obtained. Subsequently, the thickness of 60 μm
The side of the aluminum metal foil was melt-etched and plated with nickel and gold to form a ring resonance circuit for dielectric property evaluation.

(Example 2) On the above-mentioned two metal substrates subjected to electrochemical etching and further subjected to anodizing treatment,
PTFE disversion (D-1F manufactured by Daikin)
After coating so that the film thickness becomes 20 μm,
After drying at 100 ° C. for 15 minutes and sintering at 380 ° C. for 15 minutes, two composite substrates were obtained. These two composite base materials are combined with the P
With the TFE-coated side facing inward, a thickness of 0.5
mm PTFE sheet was sandwiched from both sides in a sandwich shape and joined by hot pressing to obtain a double-sided metal substrate. Subsequently, the side of the aluminum metal foil having a thickness of 60 μm was melt-etched and plated with nickel and gold to form a ring resonance circuit for dielectric property evaluation.

(Example 1)
With respect to the ring resonance circuit of (Example 2), the electrical characteristics and the adhesion between the metal layer and the dielectric layer were measured, a heat cycle test, and a thermal shock test were performed.

As the electrical characteristics, the transmission characteristics at 10 GHz were evaluated using a network analyzer.

The adhesion between the metal layer and the dielectric layer was measured as follows. After sticking a strong adhesive tape on the metal surface, or pasting the tape with an adhesive, make a cut with a predetermined width and a depth that reaches the dielectric layer, and tape in the direction in which the metal layer is peeled. , And the 180 ° peel strength is measured and converted to a unit of 1 cm in width.

Table 1 shows the measurement results of the electrical characteristics and the adhesive strength.

[0019]

[Table 1]

The heat cycle is performed in the gas phase at 120 ° C. 2
A cycle of 0 minutes and −30 ° C. for 20 minutes was repeated 20 times a day, and this was performed for 10 days to obtain 200 heat cycles. Thermal shock was performed by immersion in dry ice-methanol immediately after immersion in a 120 ° C. oil bath for 10 minutes.

As a result of the above heat cycle and thermal shock,
In both Example 1 and Example 2, peeling off of the circuit did not occur. In addition, as shown in Table 1, good results were obtained in the electrical properties and the adhesive strength.

[0022]

The circuit board of the present invention has a strong bonding force between the metal layer and the dielectric layer, has no problem such as peeling during the circuit forming process, and has a low dielectric constant and low dielectric loss characteristics of PTFE. It can be utilized and is very preferable as a high frequency circuit board having a frequency of about 0.5 to 30 GHz. In addition, environmental reliability is high,
After the circuit was formed, the substrate was bent at R10 with the circuit surface outside, but the circuit was not peeled off and post-processing was possible.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01P 3/02 H01P 3/02 H05K 1/05 H05K 1/05 A 3/06 3/06 A 3/44 3/44 A (72) Inventor Naota Kaminishi 1-3-1 Shimaya, Konohana-ku, Osaka-shi Sumitomo Electric Industries, Ltd. Osaka Works (72) Inventor Toshihiro Sakamoto 1-1-3, Shimaya, Konohana-ku, Osaka-shi Sumitomo Electric Industries, Ltd. Osaka Works F-term (reference) 4F100 AB01B AB01C AB10B AB10C AB31B AB31C AB33 AK17A AK17D AK18 BA03 BA04 BA06 BA10B BA10C BA13 DD07B DD07C EH462 EJ15B EJ15J EJ15J06 EJ17 EJ17 J06 EJ17 EJ17 EJ17 YY00C 5E315 AA03 BB01 BB03 BB14 CC01 CC14 CC25 DD05 DD16 GG14 5E339 AB02 AB07 AD01 BC03 BE11 FF02 FF10 GG01 5E343 AA02 AA22 AA36 AA38 BB05 BB28 BB67 DD76 EE42 EE52 GG 04

Claims (5)

[Claims] 1. Surface roughness of two metal substrates on both upper and lower surfaces of a dielectric layer of a perfluorinated polymer, respectively, by surface roughening including at least chemical or electrochemical etching in the process. The surface roughened to Ra 0.1 μm or more and 20 μm or less is directly joined to give an adhesive force of 1 kg / cm or more due to physical adhesive force between the metal layer and the dielectric layer. A high-frequency circuit board or antenna board, wherein a dielectric substrate having a metal layer is manufactured, and a circuit is formed by etching the one or both metal layers. 2. The surface roughness of two metal substrates on both upper and lower surfaces of a dielectric layer of a perfluorinated polymer, each of which includes at least chemical or electrochemical etching during the process, thereby reducing the surface roughness. Ra0.1μm or more surface roughened to 20μm or less, via an anodized film, bonded,
1 kg due to physical adhesion between metal layer and dielectric layer
A high-frequency circuit board or antenna, wherein a dielectric substrate having a metal layer on both sides is produced by applying an adhesive force of at least / cm, and a circuit is formed by etching the metal layer on one or both sides. substrate. 3. The high-frequency circuit board or antenna board according to claim 1, wherein the metal base is aluminum or an aluminum alloy. 4. The surface roughness of at least one surface of each of the two metal substrates is increased by performing a surface roughening process including at least chemical or electrochemical etching during the process.
Ra Roughened to 0.1μm or more and 20μm or less, bonded to the upper and lower surfaces of the dielectric layer of perfluorinated polymer without using a primer or an adhesive, and the physical adhesion between the metal layer and the dielectric layer A high-frequency circuit board, wherein an adhesive force of 1 kg / cm or more is applied to produce a dielectric substrate having metal layers on both sides, and a circuit is formed by etching the metal layer on one or both sides. A method for manufacturing an antenna substrate. 5. The method of claim 1, wherein at least one surface of each of the two metal substrates has a surface roughness of at least one surface by performing at least chemical or electrochemical etching during the process.
The surface is roughened to 0.1 μm or more and 20 μm or less.
Coating and sintering a perfluorinated polymer dispersion without a primer or adhesive, and 1 kg / cm of physical adhesion between metal layer and coating layer
Two composite base materials provided with the above adhesive force are prepared, and the composite base materials are opposed to each other with the perfluorinated polymer coating layer facing each other, or directly or with another dielectric layer of the perfluorinated polymer. Producing a dielectric substrate having a metal layer on both surfaces by etching, and forming a circuit by etching the metal layer on one or both surfaces. .