JPS648926B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to electronic components, such as energy trapping piezoelectric resonators, and methods of manufacturing the same, and particularly to an improved structure and manufacturing method for providing a cavity on a substrate. Regarding.

[Conventional technology]

Recently, so-called energy binding technology has been developed, in which partial electrodes are formed on piezoelectric substrates such as piezoelectric ceramics, and mechanical vibrations in the thickness direction of the substrate are excited by electrical input signals, producing resonance or anti-resonance at specific frequencies. Embedded piezoelectric resonators have been proposed and realized. In such piezoelectric resonators, the substrate and electrodes are generally resin-molded using porous resin such as epoxy resin or phenol resin. Since the piezoelectric resonator has a structure that uses partial electrodes to generate vibrations on the substrate, the surface area including the partial electrodes provided on the substrate is made into a space or a cavity so that the vibrations are not inhibited. There is a need.

When such a cavity is provided, it is necessary to precisely regulate the formation position, shape, etc. of this cavity so that it corresponds to the electrode formation position, etc. Conventionally, as a structure that can realize this cavity regulation, for example, There is one described in Utility Model Application Publication No. 53-7159. This is done by separately manufacturing a ring-shaped spacer along the boundary between the cavity to be obtained and the exterior resin using thermoplastic resin, etc., and fixing it onto the substrate with adhesive. It is sealed with exterior resin.

[Problem that the invention seeks to solve]

However, the conventional structure described above has the following problems.

The above spacer is manufactured in advance in a separate process,
Since the structure is such that this is bonded onto the substrate, the manufacturing process and the bonding process to the substrate are increased, and productivity is correspondingly poor.

Due to the accumulation of spacer manufacturing errors and installation errors, the accuracy of the cavity formation position, shape, and dimensions is low.

Low degree of freedom in the shape of the cavity, etc.

The present invention relates to an improvement on the above-mentioned conventional structure or manufacturing method, and has high precision in the formation position and shape of the cavity, allows the shape of the cavity to be arbitrarily selected, and improves productivity and reliability at low cost. The purpose is to provide improved electronic components and methods of manufacturing the same.

[Means for solving problems]

A first aspect of the present invention provides an electronic component in which the entire substrate is sealed with an exterior resin while a cavity is provided on the electrode formation region on the substrate surface.
UV resin is cured by irradiation with UV light to form a UV resin layer having a cavity-forming opening in a shape surrounding the electrode formation area, and a portion surrounded by the opening, the substrate, and the exterior resin forms a cavity. It is characterized by being familiar.

Further, a second invention of the present application provides a method for manufacturing an electronic component, in which the entire substrate is surrounded by an exterior resin with a cavity provided above the electrode formation region on the substrate surface.
in a certain area including the electrode formation area on the substrate surface.
attaching UV resin, shielding the electrode formation region from light, irradiating UV light in this state to cure the non-light shielding portion, removing the UV resin in the electrode formation region to form a cavity forming opening; The opening is filled with a cavity-forming material, the entire substrate is covered with an exterior resin in this state, and the cavity is formed by removing the cavity-forming material by heating or chemical reaction with the exterior resin. It is said that

Here, the electrode formation region on the substrate surface in the present invention is a surface region including the vibrating electrode formed on the substrate surface, and is a portion that should be a cavity or space so that vibration is not inhibited. This electrode formation region includes not only the case where it is provided on both main surfaces of the substrate, but also the case where it is provided on only one main surface.

In addition, the UV resin layer in the present invention is used to define the formation position and shape of the cavity to be obtained, and specifically, it is removed in a later process by the cavity formation opening to form the cavity. This is to regulate the position, shape, etc. of the cavity forming material. Therefore, this UV resin layer does not necessarily need to be formed on the entire surface of the substrate, but may be formed at least only on the peripheral shape of the cavity to be obtained, that is, on the boundary portion along the electrode forming region.

In addition, the above-mentioned cavity forming material is a material that is solid or semi-solid at room temperature, such as wax or paraffin, and is easily dissolved and removed by heating, or a material that is easily dissolved and removed by heating, or a material that is formed by a chemical reaction with an exterior resin, for example. A material that erodes and is removed in the final process to form a cavity.

[Effect]

According to the electronic component and the manufacturing method thereof according to the present invention, the adhesive layer of the UV resin is cured by irradiation with UV rays, and the uncured portion is removed, thereby creating a cavity forming opening having a shape corresponding to the electrode forming area. Since the opening is formed, the accuracy of the formation position, shape, etc. of the opening, and even the formation position of the cavity, etc. can be easily improved, and as a result, the characteristics of the electronic component can be improved.

Furthermore, the shape of the aperture can be freely selected depending on the degree of blocking of UV rays, that is, the shape design of the light shielding plate, and the degree of freedom can be increased accordingly.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a two-terminal energy-containing piezoelectric resonator unit before being coated with resin according to an embodiment of the present invention. In the figure, 1 is a piezoelectric ceramic substrate, 2 is a partial electrode (vibrating electrode) provided on one main surface of the substrate 1, and 3 is a partial electrode (vibrating electrode) provided on the other main surface of the substrate 1, facing the electrode 2. ), 4 and 5 are extraction electrodes of electrodes 2 and 3, respectively,
6 and 7 are terminal electrodes electrically connected to the extraction electrodes 4 and 5, respectively.

FIGS. 2 to 8 show the steps of a method according to an embodiment of the present invention, and parts not directly related to the present invention, including the electrodes 4 and 7, are not shown.

First, as shown in FIG. 3, UV resin is applied to the energy trapping type piezoelectric resonator unit as shown in FIG. 1 or FIG.
form.

As shown in FIG. 4, after light shielding plates 9 and 10 are placed in the cavity formation portions of the upper and lower surfaces of the substrate 1, that is, the electrode formation regions including the electrodes 2 and 3 and their surroundings, ultraviolet rays are irradiated. Then, the UV resin in the non-light-shielding area, that is, the area excluding the electrode formation area, is cured to form a cured layer.

When etching is performed with the solidified layer formed, as shown in FIG. 5, the uncured UV resin in the electrode forming area is removed and cavity forming openings 11 and 12 are formed. The openings 11 and 12 are shaped to surround the electrode forming region, and regulate the placement position and shape of the cavity forming material in a subsequent process, and also the formation position and shape of the cavity.

As shown in FIG. 6, a cavity-forming material made of a material that is solid or semi-solid at room temperature and easily melts by heating, such as wax or paraffin, is placed in the cavity-forming openings 11 and 12. 13 and 14 are filled by means such as dripping or depping.

Next, as shown in Figure 7, the entire unit is
A resin 15 having a property of chemically reacting with the porous or cavity-forming materials 13 and 14 to create spaces in the areas occupied by the materials 13 and 14 is applied by a molding method, a dipping coating method, or the like.

Finally, the unit sealed with the resin 15 is dried or heated. Then, as shown in FIG. 8, the cavity-forming materials 13 and 14 are dissolved and absorbed into the resin 15, or the materials 13 and 14 and the resin 15 react with or without heating, for example, the cavity-forming material is dissolved. Cavities 16 and 17 are formed by erosion.

As described above, in this embodiment, the adhesion positions, dimensions, etc. of the cavity forming materials 13 and 14 on the substrate surface are regulated by the cavity forming openings 11 and 12 formed in the UV resin layer 8. , the cavity forming materials 13, 14, and eventually the cavities 16, 1 because of the high accuracy of the formation positions of the openings 11, 12, etc.
The formation position, shape, etc. of the resonator 7 can be set with high accuracy, and as a result, the characteristics of the resonator can be made uniform.

Further, since the cavity formation area is determined by the shape of the UV light shielding plates 9, 10,
By appropriately setting 0, the shape, position, etc. of the cavities 16 and 17 can be changed freely.
There is a very high degree of freedom in design, and by appropriately designing the shapes of the light shielding plates 9 and 10, it is possible to produce a wide variety of products in small quantities.

In addition, in this embodiment, the entire substrate 1 is covered with a hardened resin layer, so the strength of the substrate 1, which is normally thin and prone to breakage and cracks, can be improved, and this UV resin Due to its high adhesion to ceramics, unnecessary vibrations are sufficiently suppressed.

Furthermore, UV resin can be cured in a short period of time, approximately a few seconds, and is highly productive. Incidentally, the conventional method of regulating the position, dimensions, etc. of the cavity on the substrate had problems such as a complicated structure and poor workability, but this example solves these problems. .

Note that the resonator in the above embodiments is a concept that includes not only a simple resonator but also a filter, an FM discriminator, an oscillator, a frequency-impedance conversion element, and the like.

Further, in the above embodiment, the UV resin layer 8 is
However, the main function of this resin layer 8 is to determine the position, shape, and dimensions of the cavity forming materials 13 and 14, or in other words, the cavities 16 and 17 on the surface of the substrate. It is not necessary to provide the entire surface, but at least the cavity forming opening 1
It may be provided on the periphery of numbers 1 and 12.

〔Effect of the invention〕

As described above, according to the electronic component and the manufacturing method thereof according to the present invention, the placement position, shape, etc. of the cavity forming material are regulated by the cavity forming opening formed in the UV resin layer. The material has the effect of improving the accuracy of the cavity formation position, shape, etc., and the shape of the cavity can be easily set by appropriately selecting the shape of the light shielding plate.
This has the effect of greatly increasing the degree of freedom in design.

[Brief explanation of drawings]

FIG. 1 is a front view of a piezoelectric resonator unit used in one embodiment of the present invention, and FIGS. 2 to 8 are process diagrams for explaining the steps in the method of one embodiment of the present invention. In the figure, 1 is a piezoelectric ceramic substrate, 2, 3
is a partial electrode (vibration electrode), 8 is a UV resin layer, 9,
10 is a light shielding plate, 11 and 12 are cavity forming openings, 1
3 and 14 are cavity forming materials, 15 is exterior resin,
16 and 17 are cavities.

Claims (1)

[Claims] 1. An electronic component in which the entire substrate is sealed with an exterior resin with a cavity provided in an electrode formation region on the substrate surface, wherein a UV resin is applied onto the substrate.
hardened by irradiation with light, and has a cavity-forming opening shaped to surround the electrode formation area.
1. An electronic component comprising a UV resin layer formed thereon, and a portion surrounded by an opening of the resin layer, a substrate, and an exterior resin forming the cavity. 2. In a method for manufacturing an electronic component in which a cavity is provided above an electrode formation area on a substrate surface and the entire substrate is sealed with an exterior resin, UV is applied to a certain area of the substrate surface including the electrode formation area. Apply resin, shield the area on which the electrode is formed, and leave it in this state.
UV rays are irradiated to cure the non-light-shielded portions, the UV resin in the light-shielded electrode formation area is removed to form a cavity-forming opening, and the cavity-forming material is filled in the opening, and in this state A method of manufacturing an electronic component, comprising: covering the entire substrate with an exterior resin, and removing the cavity-forming material by heating or chemical reaction with the exterior resin to form a cavity.