JP2004193937A - Method for forming antenna conductor pattern of radar antenna for millimeter wave - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a formation method for an antenna conductor pattern of a radar antenna for millimeter waves which enables formation of a high-precision antenna conductor pattern on the internal surface of a plastic molding which curves with a specific curvature. <P>SOLUTION: A parabolic plastic molding 10 having predetermined curvature is manufactured by plastic molding. On the internal surface of the plastic molding 10, a plated underlying layer is formed by electroless copper plating or the like. Using the plated underlying layer as a cathode, electrolytic copper plating is performed, and a conductor layer 21 of copper of specified thickness is formed. Moreover, the conductor layer 21 is worked into a conductor pattern 21a by a laser of a wavelength of 532 nm. Furthermore, a nickel layer of predetermined thickness is formed on the surface of the conductor pattern 21a, to obtain a radar antenna 20 for millimeter waves. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for forming an antenna conductor pattern of a millimeter wave radar antenna.
[0002]
[Prior art]
Recently, an autonomous driving support system that automatically measures the distance between vehicles using a millimeter-wave radar antenna for the purpose of preventing rear-end collision of vehicles due to safety issues has been developed and partially put into practical use. .
The millimeter-wave radar antenna used in this system has a parabolic plastic molded product having a predetermined curvature and an inner surface formed with a conductor pattern having a conductor width of about 100 μm.
[0003]
Hereinafter, a method of forming the antenna conductor pattern of the millimeter wave radar antenna will be described.
2A to 2F show an example of a process of a method for forming an antenna conductor pattern of a conventional millimeter wave radar antenna.
First, a parabolic plastic molded product 10 having a specific curvature is produced by plastic molding (see FIG. 2A).
[0004]
Next, after subjecting the inner surface 10a of the plastic molded product 10 to a roughening treatment, a catalyst nucleus provision and an activation treatment, a plating base conductor layer is formed on the inner surface of the plastic molded product 10 by electroless copper plating or the like (particularly, , Not shown). Further, electrolytic copper plating is performed using the plating base layer as a cathode to form a conductor layer 21 made of copper having a predetermined thickness (see FIG. 2B).
[0005]
Next, a photosensitive layer (resist) 31 having a predetermined thickness is formed on the conductor layer 21 by a spin coating method, a dry film sticking method, or the like (see FIG. 2C).
[0006]
Next, pattern exposure is performed using the exposure mask 40 on which the light-shielding pattern 41 is formed to form a pattern latent image on the photosensitive layer (resist) (see FIG. 2D).
Here, since the exposure mask 40 is formed by forming a light-shielding pattern on a transparent rigid body such as a glass substrate, the exposure mask 40 is closely attached to the photosensitive layer (resist) 31 on the inner surface of the curved plastic molded product 10 like this time. I can't let it. For this reason, the distance changes depending on the position of the exposure mask, and a pattern difference and variation occur in the pattern shape depending on the pattern position.
[0007]
Next, the photosensitive layer (resist) 31 is developed with a dedicated developer, dried, and post-baked to form a resist pattern 31a on the conductor layer 21 (see FIG. 2E).
[0008]
Next, using the resist pattern 31a as an etching mask, the conductor layer 21 is etched with an etching solution such as a ferric chloride solution, and the resist pattern 31a is removed with a dedicated stripping solution. The antenna conductor pattern 21a is formed to obtain the millimeter wave radar antenna 30 (see FIG. 2F).
[0009]
[Problems to be solved by the invention]
As can be seen from the above-described method of forming the antenna conductor pattern, since the inner surface of the plastic molded product 10 is curved with a certain curvature, the photosensitive layer (resist) and the pattern exposure in the photolithography process when a conventional photoetching method is applied. The process cannot be applied as it is, and in particular, pattern shape distortion and pattern width variation due to positions in the pattern exposure process occur.
If a conductor pattern having a conductor width of about 100 μm is not distorted and the pattern width variation is set to a predetermined value, the production yield becomes about 10%, which is a problem.
The present invention has been devised in view of the above problems, and a high precision antenna conductor pattern can be formed on the inner surface of a plastic molded product that is curved with a specific curvature. An object is to provide a forming method.
[0010]
[Means for Solving the Problems]
In order to achieve the above object in the present invention, the present invention provides a method for processing a conductor pattern of a millimeter wave radar antenna, wherein the antenna of the millimeter wave radar antenna includes at least the following steps. This is a method for forming a conductor pattern.
(A) A step of producing a plastic molded product 10 having a predetermined curvature by plastic molding.
(B) A step of forming a plating base layer on the inner surface of the plastic molded article 10 by electroless copper plating or the like, performing electrolytic copper plating using the plating base layer as a cathode, and forming a conductor layer 21 made of copper of a predetermined thickness.
(C) a step of patterning the conductor layer 21 with a laser having a wavelength of 532 nm to form an antenna conductor pattern 21a having a predetermined pattern width and pitch.
(D) forming a nickel layer having a predetermined thickness on the surface of the conductor pattern 21a by electrolytic nickel plating or the like;
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described.
The method for forming an antenna conductor pattern of a millimeter-wave radar antenna according to the present invention is a method of forming a conductor layer made of copper formed on the inner surface of a plastic molded product having a specific curvature and having a wavelength of 532 nm having a selective processability. By performing pattern processing using a laser (green laser) beam, it is possible to form a conductor pattern with no pattern distortion and excellent pattern processing accuracy on the inner surface of a plastic molded product that is curved with a specific curvature. it can.
[0012]
Hereinafter, a method of forming the antenna conductor pattern of the millimeter wave radar antenna of the present invention will be described.
FIGS. 1A to 1C show an example of steps of a method for forming a conductor pattern of a millimeter wave radar antenna according to the present invention.
First, a parabolic plastic molded product 10 having a specific curvature is produced by plastic molding (see FIG. 1A).
[0013]
Next, after subjecting the inner surface 10a of the plastic molded product 10 to a roughening treatment, a catalyst nucleus provision and an activation treatment, a plating base conductor layer is formed on the inner surface of the plastic molded product 10 by electroless copper plating or the like (particularly, , Not shown). Further, a conductor layer 21 made of copper having a predetermined thickness is formed by electrolytic copper plating using the plating base layer as a cathode (see FIG. 1B).
Here, a conductor layer made of copper having a thickness of 2 to 3 μm is used as the conductor layer 21.
[0014]
Next, using a second harmonic laser (wavelength: 532 nm) of a Nd: YAG laser (fundamental wave: 1064 nm), the laser beam diameter and output are adjusted, and a beam scan is performed on the conductor layer 21 to obtain a predetermined width. The antenna conductor pattern 21a is formed on the inner surface of the parabolic plastic molded article 10 to obtain the millimeter wave radar antenna 20 (see FIG. 1C).
Here, the second harmonic laser (wavelength: 532 nm) of the Nd: YAG laser (fundamental wave: 1064 nm) is also called a green laser, and the beam diameter is reduced to half that of the Nd: YAG laser (fundamental wave: 1064 nm). The energy density can be quadrupled, and it is characterized by excellent workability of metals having high reflectivity such as copper.
[0015]
As described above, the conductor layer made of copper is subjected to pattern processing using the second harmonic laser (wavelength: 532 nm) of Nd: YAG laser (fundamental wave: 1064 nm), so that there is no pattern shape distortion and high precision. Can be obtained with a high yield.
In addition, since a series of patterning processes of forming a photosensitive layer (resist), exposing a pattern, and developing in a photolithography process are not required, the process of forming a conductor pattern can be simplified and cost can be reduced.
[0016]
【Example】
Hereinafter, the present invention will be described in detail with reference to examples.
First, by plastic molding, a parabolic plastic molded product 10 having a thickness of 1.7 mm, a diameter of 80 mm, and a radius of curvature of R-40 mm was manufactured using a styrene-modified resin (Zarek 120: manufactured by Idemitsu Petrochemical) (FIG. 1 (a)).
[0017]
Next, after roughening the inner surface 10a of the plastic molded article 10 with a potassium permanganate solution, a catalyst nucleus is provided with a palladium solution, and a 0.2 μm thick plating base layer is formed by electroless copper plating. Electrolytic copper plating was performed using the underlayer as a cathode to form a conductor layer 21 made of copper having a thickness of 3 μm (see FIG. 1B).
[0018]
Next, laser pattern processing was performed at a wavelength of 532 nm using a YAG green scan marker (ECOMMARKER (trade name): ML9010A, manufactured by Miyachi Technos Co., Ltd.) to form an antenna conductor pattern 21a having a pattern width of 130 μm and a pitch of 570 μm. . Further, a nickel layer having a thickness of 0.2 μm was formed by electrolytic nickel plating to obtain a millimeter wave radar antenna 20 (see FIG. 1C).
[0019]
As a result of measuring the pattern width of the antenna conductor pattern 21a of the obtained millimeter wave radar antenna using a length-measuring microscope, the pattern width of the antenna conductor pattern 21a was found to be the entire area of the millimeter wave radar antenna for a pattern width set value of 130 μm. Over a range of ± 20 μm, which was acceptable.
【The invention's effect】
As described above, by using the method of forming the antenna conductor pattern of the millimeter-wave radar antenna of the present invention, the inner surface of a parabolic plastic molded product that is curved at a specific curvature has no pattern shape distortion and high precision. A conductor pattern can be obtained with a high yield.
In addition, since a series of patterning processes of forming a photosensitive layer (resist), pattern exposure, and developing in the photolithography process are not required, the process of forming a conductor pattern can be simplified, and the manufacturing cost can be reduced.
[Brief description of the drawings]
FIGS. 1A to 1C are schematic sectional views showing an example of a method for forming an antenna conductor pattern of a millimeter wave radar antenna according to the present invention.
FIGS. 2A to 2F are schematic sectional views showing an example of a method of forming an antenna conductor pattern of a conventional millimeter wave radar antenna.
[Explanation of symbols]
10 plastic molded product 1a inner surface 20 of plastic molded product 30, 30 millimeter wave radar antenna 21 conductor layer 21a antenna conductor pattern 31 photosensitive layer (resist)
31a resist pattern 40 exposure mask 41 light-shielding pattern

Claims (1)

A method for processing a conductor pattern of a millimeter wave radar antenna, comprising at least the following steps:
(A) A step of producing a parabolic plastic molded product (10) having a predetermined curvature by plastic molding.
(B) A plating base layer is formed on the inner surface of the plastic molded product (10) by electroless copper plating or the like, and electrolytic copper plating is performed using the plating base layer as a cathode to form a conductor layer (21) made of copper having a predetermined thickness. Forming step.
(C) A step of patterning the conductor layer (21) with a laser having a wavelength of 532 nm to form an antenna conductor pattern (21a) having a predetermined pattern width and a predetermined pitch.
(D) forming a nickel layer having a predetermined thickness on the surface of the conductor pattern (21a) by electrolytic nickel plating or the like;

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