JP3122025B2 - Plate type dielectric lens structure and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure having a dielectric lens used for an antenna, a radar, and the like, and more particularly to a dielectric lens structure having a flat plate shape.

[0002]

2. Description of the Related Art Dielectric lenses have been used for good transmission and reception of radio waves with antennas and radars. This dielectric lens is used to enhance the directivity of radio waves during transmission, and is used to focus weak radio waves to a receiver during reception.

Conventionally, as a method of manufacturing a dielectric lens, in the case of a resin lens, a molten resin is put into a mold such as a metal and cooled to solidify the resin, or a method of forming a ceramic lens is used. Are obtained by filling a ceramic powder into a mold of metal or the like, press-molding, and sintering.

[0004]

However, according to the above-mentioned method, there is a problem that an expensive and high-precision mold is required, so that the production cost is increased.

[0005] Recently, conventional dielectric lenses have
Although provided separately from the circuit board, it is required to incorporate these dielectric lenses into a structure such as a wiring board or a package in order to reduce the size of the device. In response to such demands, for example, a separately manufactured rod lens, plano-convex lens, or the like is mounted in a substrate using a jig or the like, or is adhesively fixed. The work is cumbersome and requires fine position control such as positioning, so it is difficult to directly incorporate or attach it to a structure such as a circuit board or package where fine wiring is formed. Met.

Accordingly, an object of the present invention is to provide a dielectric lens structure which can be formed without using a mold and which can be integrally formed in a structure such as a circuit board or a package. It is the purpose.

[0007]

Means for Solving the Problems As a result of repeated studies on the above-mentioned problems, the present inventors have found that a substrate having a concave portion made of a low dielectric constant material and having a substantially curved inner surface has a high dielectric constant in the concave portion. It has been found that the above object can be achieved by adopting a structure in which the buried material is embedded.

In a method of manufacturing a dielectric lens according to the present invention, a plurality of sheets made of a low dielectric constant material and having holes having different diameters are concentrically laminated so that the diameters gradually change so that a concave portion is formed. And a step of burying a high dielectric constant material in the concave portion.

[0009]

According to the flat type dielectric lens of the present invention, a dielectric lens made of a high dielectric constant material can be built in a substrate made of a low dielectric constant material. In addition, a dielectric lens can be incorporated.

In addition, according to the manufacturing method of the present invention, since it can be formed integrally with a dielectric material by simultaneous sintering without using a conventional mold, it can be manufactured easily and inexpensively. can do. Moreover, according to such a manufacturing method, a dielectric lens can be manufactured at the same time as manufacturing a circuit board or a package having a wiring layer.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The basic structure of a flat dielectric lens structure according to the present invention is, as shown in the perspective view of FIG. 1 and the sectional view of FIG. A concave portion 2 having an inner surface formed of a substantially curved surface is formed, and a high dielectric constant material 3 is embedded in the concave portion 2 to form a flat plate type structure. Note that the low dielectric constant material means that the material has a lower dielectric constant than the high dielectric constant material filled in the recess 2. In such a structure, by forming a substantially curved surface such that the inner surface of the concave portion matches the spherical surface of the lens, the high dielectric constant material embedded therein has a substantially lens shape and functions as a dielectric lens body.

In the present invention, in forming such a plate-type dielectric, a method of forming the concave portion 2 having a substantially spherical inner surface on a substrate made of a low dielectric material is made of a material having a low dielectric constant. Although it can be formed by mechanically processing the substrate, mechanical processing is difficult when the substrate 1 also serves as a circuit board.

Accordingly, as shown in FIG. 3, the recess 2 is formed by concentrically laminating a plurality of sheets 5 having holes 4 having different diameters so that the diameter of the holes 4 gradually changes.
The recess can be formed by a multi-stage substantially spherical surface as shown in FIG.

Then, a high dielectric constant material is buried in the recess of the substrate manufactured as described above.

As a method of embedding a high dielectric constant material, as shown in FIG. 3, a hole 4 having a high dielectric constant having a diameter equal to or slightly smaller than the diameter of the hole 4 of each sheet is used. The sheets 6 can be buried by laminating the sheets 6 and bringing them into close contact with the sheet 5 made of a dielectric material. Also, in FIG. 3, before laminating the sheets made of the low dielectric constant material, the holes 4 of each sheet 5 are stacked.
After a high dielectric constant material is filled in advance, the layers may be laminated.

In this case, when the low dielectric constant material and the high dielectric constant material are ceramic materials and can be sintered at the same firing temperature, each sheet is constituted by a green sheet formed by molding a ceramic powder by a doctor blade method or the like. Then, the substrate made of the sheet-shaped molded body made of the low dielectric constant material and the high dielectric constant material embedded in the concave portion can be simultaneously fired and integrated.

As another method, as shown in FIG. 4, a viscous material 7 such as a slurry made of a high dielectric material is placed in a concave portion 2 of a substrate 1 made of a low dielectric material formed by the method shown in FIG. Can be poured and buried. Again,
If the low-permittivity material and the high-permittivity material are made of a ceramic material, the substrate 1 is made of a laminate of green sheets, and the slurry is made of a material containing a high-permittivity ceramic powder, the lens is formed by so-called slurry casting. Can be produced. Then, the substrate 1 and the lens-shaped ceramic molded body can be simultaneously fired and integrated.

[0018]

EXAMPLE According to FIG. 3, a plurality of green sheets were prepared using a glass ceramic powder having a relative dielectric constant of 5, and holes having different diameters were formed in each green sheet. Then, these green sheets were laminated so that the diameter of the hole gradually increased, and this was pressed against a green sheet having no hole to form a concave portion having an inner surface having a substantially spherical surface. Sheets made of glass ceramic powder having a dielectric constant of 30 are laminated in the recesses of the obtained laminate according to the diameter of each sheet, and then fired at 1000 ° C. to be integrated to produce a dielectric lens structure. did.

The characteristics of the obtained dielectric lens were confirmed by numerical calculation. The model used for the calculation is shown in FIG. The relative dielectric constant of air was set to 1.

A wave source for oscillating a sine wave was set in a low dielectric substrate having a relative dielectric constant of 5. FIG. 6 shows the electric field strength obtained from the numerical analysis. As is clear from the results of FIG.
It is understood that the sine wave oscillated from the wave source propagates in a low dielectric constant substrate having a relative dielectric constant of 5 as a spherical wave, then enters a dielectric lens, is converted into a plane wave, and is emitted into the air. . From these results, it was confirmed that the structure of the present invention functions as a dielectric lens.

[0021]

As described above in detail, according to the dielectric lens structure of the present invention, a dielectric lens made of a high dielectric material can be built in a substrate made of a low dielectric material. A dielectric lens can be built in various circuit boards and packages. Moreover, it can be formed at the same time as the manufacture of a circuit board or a package having a wiring layer.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a basic structure of a flat dielectric lens structure of the present invention.

FIG. 2 is a sectional view taken along line XX of FIG.

FIG. 3 is a view for explaining a method of manufacturing a flat plate type dielectric lens structure according to the present invention.

FIG. 4 is a view for explaining another method for manufacturing the flat plate type dielectric lens structure of the present invention.

FIG. 5 is an analytical model diagram of a flat plate-type dielectric lens structure according to an example of the present invention.

FIG. 6 is a lens characteristic diagram of a structure according to the model of FIG. 5;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 low dielectric constant substrate 2 concave portion 3 high dielectric constant material 4 hole 5 sheet

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H01Q 15/00-15/14 H01Q 17/00 H01Q 19/00-19/32

Claims (3)

(57) [Claims] 1. A flat dielectric lens structure, characterized in that a high dielectric material is buried in a concave portion of a substrate having a concave portion made of a low dielectric constant material and having a substantially curved inner surface. 2. The method according to claim 1, wherein the substrate having a concave portion having a substantially spherical inner surface is formed by concentrically laminating a plurality of sheets having holes having different diameters so that the diameter gradually changes. The flat dielectric lens structure according to claim 1. 3. A step of forming a concave portion by laminating a plurality of sheets made of a low dielectric constant material and having holes having different diameters concentrically so that the diameter gradually changes, and forming a high dielectric in the concave portion. And a step of burying a refractive index material.