JPS5851684B2 - Piezoelectric ceramic “ro” wave device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a piezoelectric ceramic p-wave device having an exterior structure such as an energy trap type ceramic filter.

Conventionally, in order to obtain a two-pressure electromagnetic filter by enclosing a piezoelectric filter element with electrodes that constitute a ceramic filter as described above, the piezoelectric filter element heated to a predetermined temperature is coated with powder such as epoxy resin. A method is used in which the coating is carried out by immersion in a liquid, but in this method (1) it is necessary to protect the working electrode part and to form a gap so that the coating resin does not come into direct contact with the working electrode part.

Japanese Patent Publication No. 5023780 proposes a method for forming the above-mentioned voids, but in this method, partial removal of the adhesive layer is cumbersome and time-consuming, and the removal contour is unclear and constant. It is difficult to coat and obtain a thick adhesive layer.

In addition, it is difficult to obtain an adhesive layer with a thickness of several 100 microns or more, and with gaps of several tens of microns, the substrate with the adhesive layer easily comes into contact with the electrode surface due to external force or temperature changes. I'm staying.

The present invention solves such problems and will be explained below with reference to the drawings shown as examples.

In FIG. 1, reference numeral 1 denotes a piezoelectric wave element constituting an energy trapping ceramic filter, which has input and output electrodes 2 and 3 on one main plane of a rectangular piezoelectric substrate 1a, and electrodes 2 and 3 on the other side. It is constructed by arranging earthing electrodes (common electrodes) 4 facing each other in a pattern as shown in the figure on the main plane.

Further, the piezoelectric wave element 1 has a conductor 2' having a predetermined pattern on one main plane.

Each conductor 2', 3', 4 of the insulator substrate 5 is bonded at a predetermined position with a conductive adhesive, for example, silver paste 8, on the insulator substrate 5 on which the conductors 3', 4' are provided. ' and each electrode 2, 3, 4 of the piezoelectric wave element 1 are electrically connected to each other.

Further, each conductor 2', 3' on the insulating substrate 5.

External connection terminals 6a, 6b, and 6c are attached to the ends of 4' with solder 7 or the like.

The insulator substrate 5 is made of a resin such as phenol, epoxy, polyimide, etc., and a printed board with copper foil adhered to its surface is etched into a predetermined pattern to form the conductors 2', 3', and 4. It is possible to use one in which a predetermined conductive film pattern is formed on a ceramic or glass substrate such as steatite or alumina by means of plating, vapor deposition, baking, or the like.

FIG. 2 is a partial cutaway of a state in which a lid 9 as shown in FIGS. 3 and 4 is attached to the surface of an insulating substrate 5 containing a piezoelectric F-wave element 1 configured as shown in FIG. 1. FIG.

As shown in FIG. 4A, which is a cross-section of FIG. Spherical recess 1
The lid body 9 is made of a metal plate, such as aluminum foil or copper foil, having an adhesive 10, and has a predetermined recess 11 formed therein by drawing or half punching.

In addition, FIG. 4B shows a sectional view of another lid body 9A that can be used in the present invention, in which a metal plate having an adhesive layer 10A is processed into a half-cut state to form a gap 11A corresponding to the gap 11. ing.

The adhesive layer attached to the lid 9 (or 9A) may be formed by applying a solvent-activated or hot-melt adhesive, or may be formed from a pressure-sensitive adhesive.

The adhesive layer 10 shown in FIG. 4A is coated with a thermosetting adhesive.

Note that double-sided adhesive tape may be used as another means for forming the adhesive layer.

The exterior in the present invention is the lid 9 (or 9A) described above.
), and the packaging process will be explained below.

The lid 9 (or 9A) is attached to the insulating substrate 5 as shown in FIG. 1 on which the piezoelectric wave element 1 is mounted with an adhesive layer 10 (or 10A).

In this case, as is clear from FIG.
) The periphery of the recess 11 (or 11A) is the piezoelectric wave element 1
Place it in a predetermined position surrounding the outer periphery of the

In addition, the external dimensions of the lid body 9 (or 9A) are such that the width W is approximately the same as the width of the insulator substrate 5, and the length L is the external connection terminal 6a.
It is desirable to set it to such an extent that it does not overlap t6b and t6c.

After attaching the cover body 9 (or 9A) to the insulating substrate 5, the cover plate body 9 (or 9A) and the conductor 4' portion which becomes the ground side of the insulating substrate 5 are connected as shown by 7'. The lid 9 (
9A) has a shielding effect on the piezoelectric wave element 1.

As shown in FIG. 5, the above-mentioned lid body having the special recessed portion is glued to the working electrode portion of the piezoelectric wave element 1 to form a predetermined gap 1.
2, the insulating substrate 5 is immersed in a liquid silicone rubber tank (not shown), and the applied silicone rubber is heated and cured to form a first coating layer 13 made of a rubber member.
form.

Thereafter, a second coating layer 14 made of a thermosetting resin material is formed by further immersing it in a thermosetting powder such as epoxy resin or a room temperature curing liquid resin bath, and then heating and curing it at the operating temperature. The piezoelectric wave element 1 can be kept in a sealed state completely shielded from the outside air.

Note that the first coating layer is formed to alleviate mechanical shock and thermal shock to the piezoelectric F-wave element 1, but it is not necessarily formed and is directly applied to the thermosetting resin layer member, i.e. The second coating layer alone may be used to cover the substrate in a sealed state.

Further, the material of the lid body used in the present invention does not necessarily have to be a metal material, and any suitable material such as plastic or paper can be used, but as mentioned above, it is necessary to obtain the shielding effect of the piezoelectric wave element. It is better to use metal materials.

Furthermore, the means for forming the recess in the lid and the shape of the recess may be arbitrary, such as an ellipse or a rectangle.

Furthermore, the above-mentioned exterior structure according to the present invention is not only applicable to a piezoelectric p-wave element mounted on an insulating substrate; 2A, 3A.

Needless to say, it is also effective to apply the present invention to a piezoelectric wave device in which the external connection terminals 6a, 6b, and 6c are directly connected to the piezoelectric wave element 1' provided with 4A.

It is clear that in this case as well, the lid is mounted on the piezoelectric substrate so that its recess is positioned with a gap in the working electrode portion of the piezoelectric filter element.

As is clear from the above embodiments, the piezoelectric wave filter of the present invention uses a lid having a concave portion, so that the piezoelectric wave filter can be easily and efficiently applied to the operating (resonant) electrode portion of the piezoelectric filter element, and reliably. Since the void portion can be formed, an exterior coating can be easily applied without damaging the characteristics of the piezoelectric filter element.

Therefore, the present invention is extremely effective in assembling and packaging with automatic assembly/manufacturing machines, and is extremely excellent in improving mass productivity and reducing costs.

[Brief explanation of the drawing]

FIG. 1 is a plan view of essential parts of an embodiment of the present invention, FIG. 2 is a partially cutaway plan view of the embodiment of the present invention with a lid attached, and FIG. 3 is a lid used in the present invention. Plan view of an example of 4th
Figure A is a sectional view taken along the line X-X in Figure 3, Figure 4B is a sectional view of another example of the lid that can be used in the present invention, and Figure 5 is a sectional view of the embodiment of the present invention in its exterior state. , FIG. 6 is a plan view of another example of a piezoelectric wave element that can be used in the present invention. 1.1'...Piezoelectric wave element, ia, la'...
...Piezoelectric substrate, 2, 3, 4, 3A, 3A, 4A...
... Electrode, 2/, 3/, 4/... Conductor,
5...Insulator substrate, 6a. 5b, 5c...External connection terminals, 7, 7'...
...Solder (or conductive adhesive), 8...
Conductive adhesive (silver paste), 9, 9A... Lid, 10, IOA... Adhesive layer, 11, 11
A...Concavity, 12...Gap, 13...
...first coating layer, 14...second coating layer.

Claims (1)

[Claims] 1. A plurality of conductors having a predetermined pattern are provided, and
'An insulating substrate with external connection terminals connected to desired conductors, a piezoelectric wave element having a plurality of electrodes, and a lid having a recess sufficient to accommodate the piezoelectric wave element. the piezoelectric wave element is disposed on the insulating substrate with each electrode of the piezoelectric wave element electrically connected to a predetermined conductor of the insulating substrate; , the lid is mounted on the insulating substrate so as to accommodate the piezoelectric filtering element in its recess, and the insulating substrate to which the lid is mounted is coated with an exterior resin coating. A piezoelectric ceramic F-wave device characterized by. 2. A patent characterized in that the lid body is formed from a metal plate, and the lid body is electrically connected to a conductor on an insulating substrate that is electrically connected to the grounding electrode of the piezoelectric wave element. A piezoelectric ceramic p-wave device according to claim 1. 3. The piezoelectric ceramic wave device according to claim 1, wherein an adhesive layer is provided on the inner surface of the lid. 4. Claims characterized in that the exterior resin coating is formed of a first coating layer made of a rubber member and a second coating layer made of a thermosetting resin material coated on the outside of the first coating layer. The piezoelectric ceramic p-wave device according to item 1, item 2, or item 3. 5. A piezoelectric F-wave element configured such that several electrodes are provided in a predetermined pattern on the surface of a piezoelectric substrate, and an external connection terminal is directly connected to the end of the electrode, and the piezoelectric The piezoelectric wave element is provided with a lid having a concave portion capable of covering at least the working electrode portion of the piezoelectric wave element with a required gap, and the lid body is arranged such that at least the working electrode portion of the piezoelectric wave element is located in the concave portion. 1. A piezoelectric ceramic filter, wherein the piezoelectric wave element is mounted on a surface of a piezoelectric substrate and is covered with an exterior resin coating. 6. The piezoelectric ceramic p according to claim 5, characterized in that the lid body is formed of a metal plate, and the lid body is electrically connected to the grounding electrode of the piezoelectric offshore wave element.
Wave equipment. 7. The piezoelectric ceramic wave device according to claim 5, wherein an adhesive layer is provided on the inner surface of the lid. 8 Claims characterized in that the exterior resin coating is formed of a first coating layer made of a rubber member and a second coating layer made of a thermosetting resin material coated on the outside thereof. The piezoelectric ceramic F-wave device according to item 5, 6, or 7.