JP2011244401A - Method of manufacturing planar antenna and planar antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-priced planar antenna having a sharp directivity and excellent radio wave characteristics and a method of manufacturing the same.SOLUTION: A method of manufacturing a planar antenna includes the steps of: forming patterns 3, 4 comprised of a plurality of projections on a surface of a substrate 1; tightly adhering masks 23, 25 having holes 22, 24 corresponding to the patterns 3, 4 on the surface of the substrate 1 where the patterns 3, 4 are formed; performing processing for reducing a tight adhesion strength for a conductor film on the surface of the substrate exposed from the holes 22, 24 by performing strong ultraviolet ray radiation 26 while tightly adhering the substrate 1 with the masks 23, 25; performing processing for improving the tight adhesion strength for the conductor film on the surface of the substrate other than a portion 27 where the tight adhesion strength is reduced by performing appropriate ultraviolet ray radiation 28 after the masks 23, 25 are removed; forming a conductor film 2 with a predetermined film thickness on the surface of the substrate; and removing conductor films 29, 30 formed on the portion 27 where the tight adhesion strength for the conductor film on the substrate 1 is reduced.

Description

  The present invention relates to a planar antenna manufacturing method and a planar antenna, and more particularly to a method for peeling a conductor film on a pattern surface.

  In recent years, communication systems using radio have been widely used against the background of highly information-oriented society, and the development of communication systems using microwave and millimeter wave regions with a large amount of information is particularly remarkable. In such a communication system, the planar antenna is suitable as an input / output device for a short-wavelength wireless system.

  By the way, it is necessary to make the size of the antenna in accordance with the size of the wavelength of the electric (magnetic) wave, and when the wavelength is shortened, the shape of the antenna as the input / output device needs to be miniaturized. As a result, in recent antennas, the dimensional accuracy of the antenna is required to have a fine processing technique. Conventionally, antennas such as slot patterns and patch patterns have been formed using etching technology, but microfabrication has a large effect on the antenna characteristics, and there is a disadvantage that conventional etching technology cannot produce large quantities with high accuracy. It was. In particular, at least 1% of the wavelength is required for the millimeter wave, and for example, a size of several tens of μm is required at 50 GHz. It is conceivable to apply a microfabrication technique applicable to the LSI manufacturing process for such a demand, but such an technique cannot manufacture an inexpensive antenna.

  Therefore, in Patent Document 1, for example, a predetermined pattern, which is a region not covering the conductor on the substrate, and the substrate are integrally formed by an injection molding method, so that the slot of the planar antenna having the predetermined pattern can be formed with high dimensional accuracy. A method of forming has been proposed. Manufacturing the dielectric by the injection molding method makes it easy to mass-produce the antenna once the dielectric mold including a predetermined pattern is formed, and the antenna can be molded at low cost. In addition, the injection molding method can mold a predetermined pattern in units of microns, and can provide a small antenna suitable for shortening the wavelength.

  In Patent Document 1, in order to function as an electrical antenna pattern, the conductor film formed on the slot pattern of the convex portion and the power supply slot pattern is removed. Specifically, grinding and polishing operations, which are mechanical means, are performed, and the tip of the convex portion of the dielectric is simultaneously removed together with the conductor film on the convex portion.

JP 2003-115718 A

  In Patent Document 1, the conductor film is removed using mechanical means such as polishing and grinding. However, for example, when a grinding apparatus is used as the mechanical means, the flatness of the substrate surface is not sufficient. The height of the protrusions cut by grinding differs depending on the location, and the radio wave characteristics vary. In addition, since the grinding apparatus itself is expensive, the price of the antenna increases as a result.

  The present invention has been made to solve the above problems, and provides an inexpensive planar antenna having sharp directivity and good radio wave characteristics, and a method for manufacturing the same.

  In order to solve the above-described problems, a first planar antenna manufacturing method of the present invention includes a substrate made of a resin dielectric, a predetermined pattern formed on the substrate, and the above-mentioned other than the predetermined pattern. A method of manufacturing a planar antenna comprising a conductor film covering a surface of a substrate, wherein a pattern forming step of forming a pattern composed of a plurality of convex portions on a surface of a flat substrate and a hole corresponding to the pattern are formed A mask adhering step for adhering the mask having the pattern on the surface of the substrate on which the pattern is formed, and the conductor film on the substrate surface exposed from the hole in a state in which the substrate and the mask are in intimate contact with each other. A process for reducing the adhesion of the substrate, which reduces the adhesion, and after removing the mask, improves the adhesion to the conductor film on the substrate surface other than the portion where the adhesion is reduced. A substrate adhesion improving process for performing the treatment, a conductor film forming step for forming a conductor film with a predetermined film thickness on the substrate surface, and a conductor formed on a portion of the substrate where the adhesion to the conductor film is reduced And a conductor film removing step for removing the film.

  The second planar antenna manufacturing method of the present invention includes a substrate that is a dielectric made of resin, a predetermined pattern formed on the substrate, and a conductor film that covers the surface of the substrate other than the predetermined pattern. And a mask contact process in which a mask having a hole corresponding to the pattern is adhered to the surface of a flat substrate, and the substrate and the mask are in contact with each other. A substrate adhesion lowering process for performing a process for reducing the adhesion of the substrate surface exposed from the holes to the conductor film, and a substrate surface other than the portion where the adhesion is reduced after removing the mask. A substrate adhesion improving process for performing a process for improving the adhesion to the conductor film; a conductor film forming process for forming a conductor film with a predetermined thickness on the substrate surface; and the conductor film on the substrate. Adhesion is characterized in that it comprises a conductive film removal step of removing the conductive film formed on the portion of reduced.

  The planar antenna of the present invention is manufactured by using the planar antenna manufacturing method of the present invention.

  According to the method for manufacturing a planar antenna of the present invention, it is possible to remove a conductor film on a predetermined pattern in a short time without requiring an expensive polishing apparatus or grinding apparatus, sharp directivity, and good radio wave characteristics. A planar antenna can be manufactured at low cost.

  In addition, the planar antenna of the present invention can realize an inexpensive planar antenna having sharp directivity and good radio wave characteristics by using the method for manufacturing a planar antenna of the present invention.

It is a schematic sectional drawing which shows the structure of the planar antenna which concerns on Embodiment 1 of this invention. It is sectional drawing for demonstrating the manufacturing method of the board | substrate which has a pattern of a convex part in Embodiment 1 of this invention. It is sectional drawing for demonstrating the manufacturing method of the planar antenna which concerns on Embodiment 1 of this invention. It is sectional drawing for demonstrating the manufacturing method of the planar antenna which concerns on Embodiment 2 of this invention. It is sectional drawing for demonstrating the manufacturing method of the planar antenna which concerns on Embodiment 3 of this invention.

  The first planar antenna manufacturing method of the present invention includes a substrate that is a dielectric made of resin, a predetermined pattern formed on the substrate, and a conductor film that covers the surface of the substrate other than the predetermined pattern. A pattern forming step of forming a pattern composed of a plurality of convex portions on a surface of a flat substrate, and a mask having a hole corresponding to the pattern. A mask adhesion step for bringing the substrate and the mask into close contact with each other, and a process for reducing the adhesion force of the substrate surface exposed from the hole to the conductor film in a state where the substrate and the mask are in close contact with each other. Substrate adhesion reduction processing step, and after removing the mask, the substrate adhesion improvement is performed to improve the adhesion to the conductor film on the substrate surface other than the portion where the adhesion is reduced A conductor film forming step for forming a conductor film with a predetermined film thickness on the substrate surface; and a conductor film removal for removing the conductor film formed on the portion of the substrate where the adhesion to the conductor film is reduced And a process.

  The second planar antenna manufacturing method of the present invention includes a substrate that is a dielectric made of resin, a predetermined pattern formed on the substrate, and a conductor film that covers the surface of the substrate other than the predetermined pattern. And a mask contact process in which a mask having a hole corresponding to the pattern is adhered to the surface of a flat substrate, and the substrate and the mask are in contact with each other. A substrate adhesion lowering process for performing a process for reducing the adhesion of the substrate surface exposed from the holes to the conductor film, and a substrate surface other than the portion where the adhesion is reduced after removing the mask. A substrate adhesion improving process for performing a process for improving the adhesion to the conductor film; a conductor film forming process for forming a conductor film with a predetermined thickness on the substrate surface; and the conductor film on the substrate. Adhesion is characterized in that it comprises a conductive film removal step of removing the conductive film formed on the portion of reduced.

  In the substrate adhesion lowering treatment step, as a treatment for reducing the adhesion of the substrate surface to the conductor film, a method of applying a release agent such as pigment ink or a method of irradiating ultraviolet rays can be used. In particular, when performing ultraviolet irradiation, it is known that the resin substrate is modified by irradiating ultraviolet rays with a certain amount of energy (predetermined amount of ultraviolet irradiation) to improve the adhesion to the conductor film. Yes. This time, the present inventor has confirmed through experiments that the substrate surface becomes brittle by irradiating a larger amount of ultraviolet rays with the ultraviolet irradiation amount exceeding the predetermined amount. In view of this, in the substrate adhesion lowering treatment step, for the purpose of reducing the adhesion between the substrate surface and the conductor film, a larger amount of ultraviolet rays is irradiated than the ultraviolet irradiation amount that improves the adhesion. Specifically, the irradiation time may be lengthened.

  In the substrate adhesion improving process step, as a process for improving the adhesion of the substrate surface to the conductor film, a reverse sputtering method, a plasma treatment, an interface modification method by ultraviolet irradiation, or the like can be used. In particular, it is preferable to improve the adhesion by using the same ultraviolet irradiation as in the substrate adhesion reduction processing step because the process becomes simpler.

  In the conductor film forming step, electroless plating, vapor deposition, or sputtering is used to form the conductor film. For example, in the case of forming a copper conductor film, it is preferable to use a sputtering method because a dense film is obtained and conductivity is higher than a film formed by a plating method or the like. However, if a thick conductor is formed by sputtering, cracks and the like are likely to occur due to stress. Therefore, a conductor closer to the substrate surface is formed thin by sputtering and then conductive to the desired thickness by electrolytic plating. A body may be formed. The conductor formed by sputtering here is preferably thicker than the skin effect. Of course, the conductor film is not limited to copper, and for example, aluminum, silver, nickel, and the like function in the same manner. In addition, the conductor film is formed to have a predetermined thickness on the substrate surface in consideration of the skin effect, but is not formed in a predetermined region on the substrate surface (a position where the slot pattern and the power supply slot pattern are formed). By making this predetermined area a slot, it functions as an antenna.

  In the conductor film removing step, the conductor film is removed using ultrasonic cleaning with an organic solvent or the like, or an adhesive force such as an adhesive tape. In particular, the conductor film formed on the pattern can be easily removed by first conducting ultrasonic cleaning for a short time and then removing the conductor film using the adhesive force of the adhesive tape. As a result, there is no change in the substrate surface state (scratches, Ra, etc.) of the removed part before and after removing the conductor film. In addition, when the pattern is a convex portion, there is almost no change in the height of the convex portion, which has been a problem with conventional polishing apparatuses and grinding devices, and before and after removing the conductor film, the tip of the convex portion No processing scratches on the substrate surface. Further, by using ultrasonic cleaning, the conductor films on the patterns on both sides can be peeled simultaneously, and a large number of substrates can be peeled at once. Therefore, according to the present invention, an expensive polishing apparatus or grinding apparatus is not required, and the conductor film can be removed in a short time, so that an inexpensive antenna is finally obtained.

  Hereinafter, a method for manufacturing a planar antenna according to the present invention and an embodiment of the planar antenna will be described with reference to the drawings.

(Embodiment 1)
First, an example of the planar antenna and the manufacturing method thereof according to the present invention will be described as Embodiment 1. FIG. 1 is a schematic cross-sectional view showing the configuration of the planar antenna of the present embodiment.

  As shown in FIG. 1, the planar antenna 100 of the present embodiment includes a substrate 1 that is a dielectric made of resin, predetermined patterns (slot pattern 3 and power supply slot pattern 4) formed on the substrate 1, and And a conductor film 2 covering the surface of the substrate 1 other than the predetermined pattern. In the present embodiment, a resonance slot having a pattern (slot pattern 3 and power supply slot pattern 4) composed of a plurality of convex portions is formed at a predetermined position of the substrate 1 that is not covered with the conductor film 2. In FIG. 1, the slot pattern 3 and the power feeding slot pattern 4 are exaggerated in size and partially omitted in order to assist understanding of the planar antenna 100.

  The planar antenna 100 of the present embodiment has a disk shape with a diameter of 60 mm and a thickness of 1.2 mm, for example, and is realized as a small radial slot antenna. However, the application of the planar antenna 100 of the present invention is not limited to this. For example, a patch antenna, a microstrip antenna, or the like that is configured as a dielectric having a region that does not cover a conductor on a part of a conductor coating surface. The present invention can also be applied to an antenna, and there is no limitation on its size. Such a planar antenna 100 has an advantage that it can be manufactured with high dimensional accuracy even if it is small.

  The substrate 1 has a predetermined thickness, and the thickness portion serves as a waveguide and functions as a power supply circuit to each slot. In this specification, on the surface of the substrate 1, the portion where the conductor film 2 is formed is defined as the conductor covering surface 5 of the substrate, except for the portion where the slot pattern 3 and the power supply slot pattern 4 are formed. In FIG. 1, the slot pattern 3 is integrally formed with the upper surface (radiation surface) and the power supply slot pattern 4 is integrally formed with the substrate 1 as a convex pattern on the lower surface (power supply surface). The height of the convex pattern is the height of the dielectric from the flat portion of the substrate, that is, the height from the conductor covering surface 5, and the value is not larger than the thickness of the conductor film 2. Must not. Furthermore, by setting the height to at least 1/10 or less of the wavelength propagating in the dielectric, a resonance circuit is not formed in the height direction of the convex portion.

  It is preferable that the pattern consisting of a plurality of convex portions, which becomes the slot pattern 3 and the power feeding slot pattern 4, has a columnar shape. If the cross-sectional area is a substantially constant column, even if the slot is corroded, the slot shape remains the same, and stable characteristics can be maintained over a long period of time.

  The slot pattern 3 has, for example, a convex section shape and is formed in a spiral shape on the upper surface of the substrate 1. On the other hand, the power supply slot pattern 4 has, for example, a plus shape and a cross-sectional convex shape, and is formed at the center position of the lower surface of the substrate 1. Note that the shape of the power supply slot pattern 4 is not limited to a plus shape, and may be circular depending on circumstances. Further, if the power feeding slot pattern 4 cannot feed power to the slot center of the antenna 100, the radiated power pattern has a biased characteristic. Therefore, the power feeding slot pattern 4 is located at a position facing the center of the spiral spiral slot pattern 3 described above. Is provided with high accuracy.

  In the present embodiment, it is preferable that the deviation between the center of the slot pattern 3 and the center of the power supply slot pattern 4 (center of potential meaning) is within λ (wavelength) / 50. By suppressing the phase shift of the radiated electromagnetic waves in this way, the radiation pattern formed by synthesizing the radiated electromagnetic waves is improved.

  The slot pattern 3 on the upper surface (radiation surface) side and the power supply slot pattern 4 on the lower surface (power supply surface) side may be formed separately. However, the slot pattern 3 and the power supply slot pattern using an alignment jig or the like may be used. It is preferable to integrally mold 4 at the same time because the shift of the center position is small.

  In the present embodiment, as the dielectric constituting the substrate 1, for example, a cycloolefin polymer resin can be used. However, the dielectric is not limited to this, and any resin having a low dielectric constant or low water absorption can be used. And corrosion resistance can be improved. Low dielectric constant resins generally do not have polar groups with high hydrophilicity in the molecule, and therefore have a small saturated water absorption amount and are hydrophobic. In addition, since the low dielectric constant resin is not porous, it is more water repellent than inorganic materials such as alumina. Specific examples of the material include fluorine resins such as ethylene-tetrafluoroethylene copolymer, aromatic resins such as polystyrene, and polyolefin resins such as polypropylene, polyethylene, polymethylpentene, and norbornene. In view of cost and process, hydrocarbon resins are particularly preferable. In addition, fillers such as silicon dioxide, fibers, and sheets can be mixed into these materials as necessary because of the coefficient of thermal expansion. When considering use at a high frequency of 50 GHz or more, dimethanonaphthalene resin is excellent.

  Moreover, the dielectric material which comprises the board | substrate 1 may be comprised from the material whose water absorption is 0.01% or less. Thereby, water resistance and corrosion resistance can be improved. Such materials include polyolefin resins such as polypropylene, polyethylene, polymethylpentene, and norbornene.

Further, the dielectric constituting the substrate 1 may be made of a material having a coefficient of thermal expansion of 7 × 10 ⁻⁵ or less. Thereby, water resistance and corrosion resistance can be improved. Such materials include, for example, dimethanonaphthalene-based resins.

  In this embodiment, the conductor film 2 is formed on the conductor covering surface 5 of the substrate 1 with a predetermined thickness so as not to be affected by the skin effect. In this embodiment, since a 60 GHz planar antenna is assumed, the thickness of the conductor film can be set to about 2 μm, for example. As the conductive material, copper, silver, nickel, or the like can be used.

  Below, the manufacturing method of the planar antenna of this embodiment is demonstrated.

  First, an example of a manufacturing method (pattern forming process) of a substrate having a convex pattern used for manufacturing the planar antenna of the present embodiment will be described with reference to FIG.

  First, as shown in FIG. 2A, a dielectric flat plate substrate 6, a mold 8 having a recess 7 corresponding to the slot pattern 3 (FIG. 1), and a recess 9 corresponding to the feeding slot pattern 4 (FIG. 1). The flat plate substrate 6 is disposed between the surface of the mold 8 where the recess 7 is formed and the surface of the mold 10 where the recess 9 is formed. At this time, when the substrate 1 (FIG. 1) is completed, the positions of the mold 8 and the mold 10 are adjusted so that the center positions of the slot pattern 3 (FIG. 1) and the feeding slot pattern 4 (FIG. 1) are aligned.

  Then, the flat plate substrate 6 and the mold 8 and the mold 10 are brought into close contact with each other, and as shown in FIG. 2B, from the upper surface side of the mold 8 and the lower surface side of the mold 10 by a thermal nanoimprint apparatus (not shown). Predetermined heat and pressure 11 are simultaneously applied to the flat substrate 6. For example, a pressure of 30 kN is applied at 170 ° C. As a result, the slot pattern 3 (FIG. 1) and the power feeding slot pattern 4 (FIG. 1) corresponding to the recess 7 of the mold 8 and the recess 9 of the mold 10 can be transferred to the upper surface and the lower surface of the flat substrate 6 respectively. it can.

  When the mold 8 and the mold 10 are removed after the transfer is completed, as shown in FIG. 2C, the substrate 1 on which the slot pattern 3 and the power supply slot pattern 4 are integrally formed is obtained.

  In this manner, the molds 8 and 10 having the recesses 7 and 9 corresponding to the predetermined pattern and the dielectric substrate 6 are brought into close contact with each other while applying pressure at a specific temperature, and the predetermined pattern is formed on the substrate surface. By transferring, for example, a slot or a patch can be formed on the surface of the substrate with high accuracy in units of microns, and finally a small antenna suitable for shortening the wavelength can be manufactured. Furthermore, by using the molds 8 and 10 having the recesses 7 and 9 corresponding to a predetermined pattern, it is easy to mass-produce the substrate 1 having high accuracy and excellent antenna directivity. Manufacturable. This manufacturing method can also be used for manufacturing a filter required for an antenna.

  In addition, the shaping | molding method of the board | substrate which has a predetermined pattern which consists of a some convex part is not restricted to the said thermal nanoimprint method, The optical nanoimprint method and the injection molding method can also be used.

  Next, an example of the manufacturing method of the planar antenna using the board | substrate 1 obtained in FIG. 2 is demonstrated using FIG.

  First, as shown in FIG. 3A, a substrate 1 having a predetermined pattern composed of a plurality of convex portions, a mask 13 having holes 12 corresponding to the slot patterns 3, and holes 14 corresponding to the power supply slot patterns 4 are provided. A mask 15 is prepared. The sizes of the holes 12 of the mask 13 and the holes 14 of the mask 15 are made slightly larger than the shapes of these patterns so that the slot pattern 3 and the power supply slot pattern 4 can pass therethrough.

  Next, as shown in FIG. 3B, the mask 13 is laminated (adhered) to the upper surface of the substrate 1 so that the slot pattern 3 of the substrate 1 penetrates the hole 12 of the mask 13, and the substrate is placed in the hole 14 of the mask 15. The mask 15 is brought into close contact with the lower surface of the substrate 1 so that the one power supply slot pattern 4 penetrates (mask contact step).

  For example, two glass substrates 17 having a surface to which the pigment ink 16 is applied as a release agent are prepared, and the mask 13 and the glass substrate 17 between the surfaces of the two glass substrates 17 to which the pigment ink 16 is applied are prepared. The substrate 1 in a state where the mask 15 is in close contact is disposed (FIG. 3B), the glass substrate 17 is brought close to the substrate 1, and the pigment ink 16 is exposed from the holes 12 and 14 of the masks 13 and 15. Apply to the tip surface. (Substrate adhesion reduction processing step). Here, the pigment ink 16 was applied on the glass substrate 17 so as to have a thickness of about 10 μm. Thereby, the adhesive force with respect to the conductor film of the part 18 (FIG. 3C mentioned later) to which the pigment ink 16 is applied decreases. In this embodiment, pigment ink is used as a release agent, but dye ink, oil pen ink, and the like can also be used. Other than these, any material that is soluble in an organic solvent or that reduces the adhesion between the substrate and the conductor film may be used.

  Thereafter, when the masks 13 and 15 that are in close contact with the substrate 1 are peeled off, as shown in FIG. 3C, the substrate 1 having a portion 18 in which the adhesion to the conductor film is reduced by applying the pigment ink is obtained.

  Next, as shown in FIG. 3D, as a process for improving the adhesion between the substrate surface other than the convex patterns 3 and 4 and the conductor film, for example, a surface treatment 19 by reverse sputtering is performed (substrate adhesion improvement process). Process). Thereby, the roughness (for example, Ra) of the substrate surface is increased and the adhesion is improved. Specifically, the surface treatment 19 can be executed by performing reverse sputtering using a magnetron sputtering apparatus in an argon atmosphere under conditions of power of 500 W and sputtering time of 60 seconds.

  Next, as shown in FIG. 3E, a conductor film is formed on the entire surface of the substrate 1 by sputtering (conductor film forming step). As a result, the conductor films 2, 20, and 21 are uniformly formed on the slot pattern 3, the power supply slot pattern 4, and the substrate 1 body. Actually, a conductor film is also formed on the side surface of the convex portion, but this is omitted in the drawing.

  However, in the state shown in FIG. 3E, the slot pattern 3 and the power feeding slot pattern 4 are concavo-convex patterns covered with the conductor films 20 and 21, respectively, and do not function as electrical antenna patterns. Therefore, in order to make the slot pattern 3 and the power supply slot pattern 4 electrical antenna patterns, the conductor films 20 and 21 formed on the portion 18 where the adhesion to the conductor film is reduced are removed (conductor film removal step). ). In addition, the pigment ink applied to the front end surface (18) of each pattern is also washed by this conductor film peeling process.

  Here, as a peeling method of a conductor film, the method of peeling using ultrasonic cleaning with an organic solvent etc., adhesive force, such as an adhesive tape, is mentioned. Specifically, after first performing ultrasonic cleaning with, for example, acetone for several minutes, the adhesion to the conductive film is easily reduced in a short time by removing the conductive film using, for example, the adhesive strength of the cellophane tape. The conductor films 20 and 21 formed on the portion 18 can be removed. As a result, there is almost no variation in the height of the convex portions, which has been a problem with conventional polishing apparatuses and grinding apparatuses, and processing defects on the substrate surface do not occur. Further, by using ultrasonic cleaning, the conductor films 20 and 21 on the patterns 3 and 4 formed on the upper surface and the lower surface of the substrate 1 can be simultaneously peeled, and more than one substrate can be peeled at a time. It becomes. Therefore, an expensive polishing apparatus or grinding apparatus is not required, and the conductor film can be removed in a short time, so that an inexpensive antenna can be finally obtained.

By obtaining the above process, as shown in FIG. 3F, the planar antenna 100 having the slot pattern 3 and the feeding slot pattern 4 that are not covered with the conductor film in a predetermined region on the substrate 1 can be obtained. After obtaining the planar antenna shown in FIG. 3F, a thin film such as a SiO ₂ film or a SiN film may be formed on the conductor film 2 as a protective layer. However, it is necessary to use a protective layer that does not affect the radio wave characteristics of the antenna.

  Thus, according to the planar antenna manufacturing method of the present embodiment, an antenna having sharp directivity and good radio wave characteristics can be obtained. Moreover, since it is excellent also in mass productivity, it can bring about the reduction of manufacturing cost.

(Embodiment 2)
Next, another example of the planar antenna manufacturing method of the present invention will be described as a second embodiment. Since the manufacturing method of the substrate having the convex pattern used for manufacturing the planar antenna of the present embodiment has been described with reference to FIG. 2 in the first embodiment, the description thereof is omitted here and is obtained in FIG. Another example of a method for manufacturing a planar antenna using the substrate 1 will be described with reference to FIG.

  First, as shown in FIG. 4A, a substrate 1 having a predetermined pattern composed of a plurality of convex portions, a mask 23 having a hole 22 corresponding to the slot pattern 3, and a hole 24 corresponding to the power supply slot pattern 4 are provided. A mask 25 is prepared. The sizes of the hole 22 of the mask 23 and the hole 24 of the mask 25 are slightly larger than the shapes of the respective patterns so that the slot pattern 3 and the power supply slot pattern 4 can pass therethrough.

Next, as shown in FIG. 4B, the mask 23 is laminated (adhered) to the upper surface of the substrate 1 so that the slot pattern 3 of the substrate 1 penetrates the hole 22 of the mask 23, and the substrate is placed in the hole 24 of the mask 25. The mask 25 is brought into close contact with the lower surface of the substrate 1 so that the single power supply slot pattern 4 penetrates (mask contact step). And the intense | strong ultraviolet-ray 26 is irradiated to the both main surface sides of the obtained laminated body (board | substrate adhesive force reduction process process). For example, an ultraviolet irradiation lamp having a wavelength of 185 nm is used, and ultraviolet irradiation with an illuminance of about 15 mW / cm ² is performed for 5 minutes with the distance between the lamp and the substrate 1 being 5 cm apart. Thereby, the adhesive force with respect to the conductor film of the portion 27 (FIG. 4C described later) irradiated with the strong ultraviolet ray 26 is reduced.

  Here, the reason why it is important to reduce the adhesion between the substrate surface and the conductor film by irradiating ultraviolet rays will be described. When the resin substrate is irradiated with a predetermined amount of ultraviolet rays (appropriate ultraviolet irradiation), the surface of the substrate is modified to improve the adhesion to the conductor film, and the resin substrate is irradiated with strong ultraviolet rays exceeding the predetermined amount. If it continues, it will be known that the substrate surface becomes brittle and the adhesion to the conductor film decreases. Therefore, in the present invention, for the purpose of reducing the adhesion of the substrate surface to the conductor film, the ultraviolet irradiation is carried out so that the ultraviolet irradiation amount is larger than the predetermined amount. Here, when an ultraviolet irradiation experiment was performed using the resin substrate of the present embodiment, when the ultraviolet irradiation was performed for 2 minutes using the ultraviolet irradiation lamp, the adhesion to the conductor film on the substrate surface was improved. When ultraviolet irradiation was further performed for 3 minutes, the result that the adhesive force with respect to a conductor film fell was obtained. Therefore, the ultraviolet irradiation time is set to 5 minutes in the substrate adhesion lowering process of the present embodiment. Note that the same result is obtained by changing the irradiation conditions even with a lamp having a wavelength of 254 nm.

  Thereafter, when the masks 23 and 25 adhered to the substrate 1 are peeled off, as shown in FIG. 4C, the substrate 1 having a portion 27 in which the adhesion force to the conductor film is reduced by irradiation with the strong ultraviolet ray 26 is obtained.

  Next, as shown in FIG. 4D, as a process for improving the adhesion between the substrate surface other than the convex patterns 3 and 4 and the conductor film, the ultraviolet irradiation lamp used in the substrate adhesion lowering process is used. Appropriate ultraviolet irradiation 28 is performed (substrate adhesion improving process step). Here, the ultraviolet irradiation time was 2 minutes. Thereby, the adhesive force with respect to the conductor film of the substrate surface other than the part in which the patterns 3 and 4 were formed can be improved. Here, the state in which the adhesion to the conductive film has been improved in the substrate adhesion enhancement treatment process means that all the substrates are cellophane when the plurality of substrates are irradiated with ultraviolet rays and the substrates are brought into contact with the cellophane tape. This means that the tape is stuck.

  Next, as shown in FIG. 4E, a conductor film is formed on the entire surface of the substrate 1 by sputtering (conductor film forming step). As a result, the conductor films 2, 29, and 30 are uniformly formed on the slot pattern 3, the power feeding slot pattern 4, and the substrate 1 body. Actually, a conductor film is also formed on the side surface of the convex portion, but this is omitted in the drawing.

  However, in the state shown in FIG. 4E, the slot pattern 3 and the power feeding slot pattern 4 are concavo-convex patterns covered with the conductor films 29 and 30, respectively, and do not function as electrical antenna patterns. Therefore, in order to use the slot pattern 3 and the power supply slot pattern 4 as electrical antenna patterns, the conductor films 29 and 30 formed on the portion 27 where the adhesion to the conductor film is reduced are peeled off (conductor film removal step). ). As a method for peeling the conductor film, the method described in the first embodiment may be used, for example, ultrasonic cleaning with an organic solvent or the like, and peeling using an adhesive force such as an adhesive tape.

With the above process, as shown in FIG. 4F, an antenna having a slot pattern 3 and a feeding slot pattern 4 that are not covered with a conductor film in a predetermined region on the substrate 1 can be obtained. Even if the conductor film removal step is performed, a portion 27 where the adhesion force with respect to the conductor film generated in the substrate adhesion strength reduction process step may remain, but the radio wave characteristics are not affected. Further, after obtaining the antenna shown in FIG. 4F, a thin film such as a SiO ₂ film or a SiN film may be further formed on the conductor film 2 as a protective layer. However, it is necessary to use a protective layer that does not affect the radio wave characteristics of the antenna.

  Thus, according to the planar antenna manufacturing method of the present embodiment, an antenna having sharp directivity and good radio wave characteristics can be obtained. Moreover, since it is excellent also in mass productivity, it can bring about the reduction of manufacturing cost.

(Embodiment 3)
Next, another example of the planar antenna of the present invention will be described as a third embodiment. The difference from the first and second embodiments is that the substrate is a flat plate substrate, and the predetermined pattern is a concave shape. FIG. 5 is a diagram for explaining a method of manufacturing the planar antenna according to the present embodiment.

  As shown in FIG. 5F, the planar antenna of the present embodiment includes a flat substrate 31 that is a dielectric made of resin, and predetermined patterns (slot pattern 39 and feeding slot pattern 40) formed on the substrate 31. And a conductor film 2 covering the surface of the substrate 31 other than the predetermined pattern. In this embodiment, a resonance slot having a predetermined pattern (slot pattern 39 and power supply slot pattern 40) is formed at a predetermined position on the substrate 31 that is not covered with the conductor film 2.

  Further, the planar antenna of the present embodiment has a disk shape with a diameter of 60 mm and a thickness of 1.2 mm, for example, and is realized as a small radial slot antenna. However, the application of the planar antenna of the present invention is not limited to this. For example, any antenna configured as a dielectric having a region where a conductor is not coated on a part of a conductor coating surface, such as a patch antenna or a microstrip antenna. It can be applied to the above, and there is no limitation on its size. Such a planar antenna has the advantage that it can be manufactured with high dimensional accuracy even if it is small.

  The substrate 31 has a predetermined thickness, and the thickness portion serves as a waveguide and functions as a power feeding circuit to each slot.

  In the present embodiment, it is preferable that the difference between the center of the slot pattern 39 and the center of the power supply slot pattern 40 (center of potential meaning) is within λ (wavelength) / 50. By suppressing the phase shift of the radiated electromagnetic waves, the radiation pattern formed by synthesizing the radiated electromagnetic waves becomes good.

  In the present embodiment, as the dielectric constituting the substrate 31, for example, a cycloolefin polymer resin can be used. However, the dielectric is not limited to this, and any resin having a low dielectric constant and low water absorption is applicable. The specific material of this dielectric is as described in the first embodiment.

  In the present embodiment, the conductor film 2 is formed on the surface of the substrate 31 with a predetermined thickness so as not to be affected by the skin effect. In this embodiment, since a 60 GHz planar antenna is assumed, the thickness of the conductor film 2 can be set to about 2 μm, for example. The conductor material is as described in the first embodiment.

  Below, the manufacturing method of the planar antenna of this embodiment is demonstrated using FIG. FIG. 5 shows an example in which the adhesion force to the conductor film is controlled by using the flat substrate 31 and performing two types of ultraviolet irradiation with different ultraviolet irradiation amounts.

  First, as shown in FIG. 5A, a dielectric flat substrate 31, a mask 33 having holes 32 corresponding to a finally obtained slot pattern 39 (FIG. 5F described later), and a finally obtained power supply slot A mask 35 having holes 34 corresponding to the pattern 40 (FIG. 5F described later) is prepared.

Next, as shown in FIG. 5B, masks 33 and 35 are laminated (adhered) on both main surfaces of the flat substrate 31 so that the center of the slot pattern 39 to be finally formed and the center of the power supply slot pattern 40 are aligned. (Mask adhesion process). And the intense | strong ultraviolet-ray 36 is irradiated to the both main surface sides of the obtained laminated body (board | substrate adhesive force reduction process process). For example, an ultraviolet irradiation lamp having a wavelength of 185 nm is used, and ultraviolet irradiation with an illuminance of about 15 mW / cm ² is performed for 5 minutes in a state where the distance between the lamp and the substrate 31 is 5 cm apart. Thereby, the adhesive force with respect to the conductor film of the part 37 (FIG. 5C mentioned later) irradiated with the strong ultraviolet ray 36 is reduced. The reason why the adhesion between the substrate surface and the conductor film is reduced or improved by irradiating ultraviolet rays is as described in the second embodiment.

  Thereafter, when the masks 33 and 35 adhered to the substrate 31 are peeled off, as shown in FIG. 5C, the substrate 31 having the portion 37 in which the adhesion to the conductor film is reduced by irradiation with the strong ultraviolet ray 36 is obtained.

  Next, as shown in FIG. 5D, as a process for improving the adhesion between the substrate surface other than the portion 37 where the adhesion to the conductor film is reduced and the conductor film, the ultraviolet irradiation lamp used in the substrate adhesion reduction process step. Is used to perform appropriate ultraviolet irradiation 38 (substrate adhesion improving process step). Here, the ultraviolet irradiation time was 2 minutes. Thereby, the adhesive force with respect to the conductor film of board | substrate surfaces other than the part 37 where the adhesive force with respect to the conductor film fell can be improved.

  Next, as shown in FIG. 5E, the conductor film 2 is formed on the entire surface of the substrate 31 by sputtering (conductor film forming step).

  However, in the state shown in FIG. 5E, the portion 37 corresponding to the finally obtained slot pattern 39 (FIG. 5F described later) and the power feeding slot pattern 40 (FIG. 5F described later) are covered with the conductor film 2. An electrical antenna pattern has not been obtained. Therefore, in order to obtain an electric antenna pattern, the conductor film 2 on the portion 37 where the adhesion is reduced is peeled off (conductor film removal step). As a method for peeling the conductor film, the method described in the first embodiment may be used, for example, ultrasonic cleaning with an organic solvent or the like, and peeling using an adhesive force such as an adhesive tape.

By obtaining the above process, as shown in FIG. 5F, an antenna having a slot pattern 39 and a feeding slot pattern 40 that are not covered with the conductor film 2 in a predetermined region on the substrate 31 can be obtained. Even if the conductor film is removed in the conductor film removal step, the portion 37 where the adhesion force to the conductor film generated in the substrate adhesion strength reduction treatment step is reduced may remain, but the radio wave characteristics are not affected. Further, after obtaining the antenna shown in FIG. 5F, a thin film such as a SiO ₂ film or a SiN film may be further formed on the conductor film 2 as a protective layer. However, it is necessary to use a protective layer that does not affect the radio wave characteristics of the antenna.

  Thus, according to the planar antenna manufacturing method of the present embodiment, an antenna having sharp directivity and good radio wave characteristics can be obtained. Moreover, since it is excellent also in mass productivity, it can bring about the reduction of manufacturing cost.

  In this embodiment, the slot antenna is shown as an example. However, in the patch antenna, for example, the slot pattern is configured as a conductor film, and the manufacturing method is otherwise the same. Further, the manufacturing method of the present invention is not limited to an antenna but can be applied to a band pass filter or the like.

  Although the preferred embodiments of the present invention have been described above, the present invention can be modified and changed in various ways within the scope of the gist thereof.

  The planar antenna of the present invention is a small planar antenna suitable for the millimeter wave band (frequency 30 to 300 GHz, wavelength 1 to 10 mm). In particular, the present invention can be applied to various wireless systems with large capacity and low cost. Such an antenna is suitable for, for example, a radar for automobile collision prevention, a short-range communication system, a wireless LAN, and wireless connection of household indoor wiring.

DESCRIPTION OF SYMBOLS 1 Dielectric board | substrate which has convex part 2 Conductor film 3 Slot pattern of convex part 4 Slot pattern for electric power feeding of convex part 5 Conductor coating | coated surface 6, 31 Flat plate substrate of dielectric material 7 Recessed part corresponding to slot pattern 8 Gold for slot pattern Type 9 Recessed part corresponding to power supply slot pattern 10 Power supply slot pattern mold 11 Pressure direction during thermal nanoimprinting 12, 22, 32 Holes corresponding to slot pattern 13, 23, 33 Mask 14, 24, 34 Power supply slot Hole corresponding to pattern 15, 25, 35 Mask 16 Pigment ink 17 Glass substrate 18 Part where pigment ink is applied (part where adhesion is reduced)
19 Surface treatment by reverse sputtering 20, 29 Conductor film on slot pattern 21, 30 Conductor film on power supply slot pattern 26, 36 UV irradiation 27, 37 Reduced adhesion 28, 38 UV irradiation 39 Slot pattern 40 Power supply Slot pattern 100 Antenna

Claims (10)

A method of manufacturing a planar antenna comprising a substrate that is a dielectric made of a resin, a predetermined pattern formed on the substrate, and a conductor film that covers a surface of the substrate other than the predetermined pattern,
A pattern forming step of forming a pattern composed of a plurality of convex portions on the surface of the flat substrate;
A mask adhesion step in which a mask having a hole corresponding to the pattern is adhered to the surface of the substrate on which the pattern is formed;
A substrate adhesion reducing process step for performing a process of reducing the adhesion of the substrate surface exposed from the hole to the conductor film in a state where the substrate and the mask are in close contact;
After removing the mask, a substrate adhesion improving process step of performing a process of improving the adhesion to the conductor film on the substrate surface other than the portion where the adhesion is reduced,
A conductor film forming step of forming a conductor film with a predetermined film thickness on the substrate surface;
And a conductor film removing step of removing the conductor film formed on the portion of the substrate where the adhesion to the conductor film is reduced. A method of manufacturing a planar antenna comprising a substrate that is a dielectric made of a resin, a predetermined pattern formed on the substrate, and a conductor film that covers a surface of the substrate other than the predetermined pattern,
A mask adhesion step for closely adhering a mask having a hole corresponding to the pattern on the surface of the flat substrate;
A substrate adhesion reducing process step for performing a process of reducing the adhesion of the substrate surface exposed from the hole to the conductor film in a state where the substrate and the mask are in close contact;
After removing the mask, a substrate adhesion improving process step of performing a process of improving the adhesion to the conductor film on the substrate surface other than the portion where the adhesion is reduced,
A conductor film forming step of forming a conductor film with a predetermined film thickness on the substrate surface;
And a conductor film removing step of removing the conductor film formed on the portion of the substrate where the adhesion to the conductor film is reduced.   The planar antenna manufacturing method according to claim 1, wherein the conductor film is a copper thin film.   The manufacturing method of the planar antenna of Claim 1 or 2 with which there is no change in the substrate surface state of the part which removed the said conductor film before and after the said conductor film removal process.   The method for manufacturing a planar antenna according to claim 1, wherein there is no change in the height of the convex portion before and after the conductor film removing step. The substrate has the property that the adhesion to the conductor film is improved up to a predetermined amount of ultraviolet irradiation, and the adhesion to the conductor film is reduced when the predetermined amount is exceeded,
The said board | substrate adhesive force reduction process process reduces the said adhesive force of the said substrate surface by irradiating an ultraviolet-ray with respect to the said board | substrate so that an ultraviolet-ray irradiation amount may be larger than the said predetermined amount. Manufacturing method of flat antenna.   3. The method for manufacturing a planar antenna according to claim 1, wherein the substrate adhesion reducing process step reduces the adhesion of the substrate surface by applying pigment ink. 4. The substrate has the property that the adhesion to the conductor film is improved up to a predetermined amount of ultraviolet irradiation, and the adhesion to the conductor film is reduced when the predetermined amount is exceeded,
3. The flat surface according to claim 1, wherein in the substrate adhesion improving process step, the adhesion of the substrate surface is improved by irradiating the substrate with ultraviolet rays so that an ultraviolet irradiation amount becomes the predetermined amount. Antenna manufacturing method.   The method for manufacturing a planar antenna according to claim 1, wherein, in the conductor film removing step, after the substrate is ultrasonically cleaned, the conductor film on the pattern is removed using an adhesive tape.   The planar antenna manufactured by the manufacturing method described in any one of Claims 1-9.

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