JPH04236512A - Ladder type piezoelectric component - Google Patents

Abstract

PURPOSE:To realize the ladder type piezoelectric component whose mount space does not need a large space. CONSTITUTION:While piezoelectric boards 1 provided with vibration electrodes 2, 3 are supported with insulation support members 5,6 from both sides of the boards 1 in the plate broadwise direction, the piezoelectric boards 1 are connected to form a composite board 9 having a board thickness in a direction vertical with respect to the board thickness direction of the piezoelectric boards 1. After the composite board 9 is inserted between seal boards 10, 10, the composite board 9 and the sealing boards 10, 10 are laminated to form a vibration space in the inside. Then conductor patterns 15a, 15b provided to the upper sealing board 10 are in electric connection with vibration electrodes 2, 3 provided in the piezoelectric board 1 to form the ladder type circuit. The electric connection between the conductor patterns 15a, 15b and the vibration electrodes 2, 3 is implemented via an end face electrode provided after, e.g. the sealing boards 10, 10 and the composite board 9 are laminated.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ladder-type piezoelectric component used in filter circuits and the like.

0002

[Prior Art and Problems] Conventionally, this type of ladder-type piezoelectric component has a plurality of piezoelectric resonators attached to one piezoelectric substrate, and two ceramic substrates with recesses are used to create a piezoelectric substrate. There was one that was sealed by sandwiching it. Separately from this, only one piezoelectric resonator is formed on one piezoelectric substrate, and after laminating a plurality of piezoelectric substrates, the laminate is stacked with two ceramic substrates provided with recesses. There was something that was sandwiched and sealed.

However, when these piezoelectric components are attached to a printed wiring board, the piezoelectric substrate is placed horizontally with respect to the printed wiring board, so a large space is required for attachment. For this reason, it has become difficult to meet the recent needs for higher integration. Therefore, an object of the present invention is to provide a ladder-type piezoelectric component that requires only a small space for mounting components.

0004

[Means for Solving the Problems] In order to solve the above problems, a ladder-type piezoelectric component according to the present invention includes (a) a piezoelectric substrate having vibrating electrodes on the front and back surfaces, and (b) the piezoelectric substrate (c) a sealing member that is bonded to the composite substrate to form a vibration space; (d) a conductor pattern that is electrically connected to a vibration electrode provided on the piezoelectric substrate to constitute a ladder circuit; It is characterized in that it is provided on at least one surface of the member or the composite substrate.

[0005]

[Operation] In the above configuration, a ladder type circuit is formed by electrically connecting the vibrating electrodes provided on the piezoelectric substrate with the conductor pattern provided on the surface of at least one of the sealing member and the composite substrate. Ru. When this piezoelectric component is attached to a printed wiring board, each piezoelectric substrate is placed horizontally and vertically to the printed wiring board, so the mounting area per piezoelectric substrate can be reduced, and the piezoelectric component can be mounted on the printed wiring board. The space required for installation is small.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a ladder-type piezoelectric component according to the present invention will be described with reference to the accompanying drawings. In the example below,
A ladder filter using an energy-trapped thickness-shear vibration mode piezoelectric resonator will be explained. [First Embodiment, FIGS. 1 to 3] The ladder type filter shown in FIG. 1 includes four piezoelectric resonators. In FIG. 1, a piezoelectric substrate 1 has metal vibrating electrodes 2 and 3 made of Ag or the like provided on its front and back surfaces by means of vapor deposition or the like. As the material of the piezoelectric substrate 1, ceramics such as Pb(ZrTi)O3 and BaTiO3 are used. Vibration in the energy trap type thickness shear vibration mode occurs at the portion where the vibrating electrodes 2 and 3 face each other. One end of each of the vibrating electrodes 2 and 3 is an extraction electrode 2a and 3a.
It is said that

The insulating holding members 5 and 6 are provided with notches 5a, 6a, and 6b for forming vibration spaces, respectively, and are fixed and held using adhesive from both sides of the front and back surfaces of both ends of the piezoelectric substrate 1. are doing. Each piezoelectric substrate 1 is connected in a horizontally vertical state by the insulating holding members 5 and 6,
A single composite substrate 9 is formed. The thickness direction of the composite substrate 9 is
It is perpendicular to the thickness direction of the piezoelectric substrate 1. Further, on the upper surface of the composite substrate 9, electrodes 8 for ensuring electrical connection with end surface electrodes 25, which will be described later, are deposited or connected to the extraction electrodes 2a or 3a for each piezoelectric substrate 1. It is formed by a method such as sputtering. Note that a similar electrode 8 may also be formed on the lower surface of the composite substrate 9.

A sealing substrate 10 is placed between the composite substrate 9 and the composite substrate 9.
are stacked one above the other. The sealing substrate 10 is provided with a recess 11 on the surface on which the vibration space is formed. In the vibrating portion of the piezoelectric substrate 1, a vibration space is secured by the notches 5a, 6a, 6b of the holding members 5, 6 and the recess 11 of the sealing substrate 10. In this embodiment, a vibration space is formed for each piezoelectric substrate 1, but by increasing the area of the recess 11, one vibration space is formed for two or three or more piezoelectric substrates 1. may be formed. In FIG. 1, electrodes 14a, 14b, 14c, 14d, and 1
4e, 14f, 14g, and 14h are provided. Conductor patterns 15a and 15b are connected to the electrodes 14b, 14e, 14g and 14c, 14d, respectively. The conductor patterns 15a and 15b are for electrically connecting the vibrating electrodes 2 and 3 of the piezoelectric substrate 1 to form a ladder type circuit. Furthermore, the resin film 20 that protects the electrodes 14a to 14h and the conductor patterns 15a and 15b is applied to the sealing substrate 10, leaving a portion 20a of the electrodes 14a to 14h.
(In Figure 1, the shaded area is the resin film 2.)
0).

FIG. 2 is a perspective view showing the appearance of the ladder type filter after lamination. Edge electrodes 2 are applied to the front and rear end surfaces of the filter by sputtering, vapor deposition, plating, etc.
5 is provided. Each end face electrode 25 is in contact with a portion 20a where the resin film 20 is not formed. This results in
Each end face electrode 25 is electrically connected to the electrodes 14a to 14h, respectively. Further, the end surface electrode 25 provided on the front end surface of the filter is electrically connected to the lead electrode 2a of the piezoelectric substrate 1, and the end surface electrode 25 provided on the back end surface of the filter is also electrically connected to the lead electrode 2a of the piezoelectric substrate 1. It is electrically connected to 3a. Therefore, electrodes 14a to 14d and electrodes 14e to 1
4h are electrically connected to the vibrating electrodes 3 and 2, respectively.

[0010] In the thus obtained filter, since the piezoelectric substrate is placed horizontally and vertically, the mounting area per piezoelectric substrate is small, and the space required for mounting on a printed wiring board is small. . FIG. 3 shows an equivalent electrical circuit diagram of the filter. Electrode 14a functions as an input electrode, electrodes 14c and 14d function as output electrodes, and electrodes 14f and 14h function as ground electrodes. Each piezoelectric resonator constitutes a ladder type circuit.

[Second Embodiment, FIGS. 4 and 5] In the second embodiment, the conductor patterns 15a and 15b provided on the sealing substrate 10 in the first embodiment are changed as shown in FIG. . FIG. 5 shows an equivalent electrical circuit diagram of this filter. The electrode 14a functions as an input electrode, and the electrode 14a functions as an input electrode.
h and 14g function as output electrodes, and electrodes 14f and 14c function as ground electrodes.

[Third Embodiment, FIGS. 6 and 7] In the third embodiment, one piezoelectric substrate 1 provided with vibrating electrodes 2 and 3 is added to the first embodiment, and five piezoelectric substrates 1 are added. It is a ladder type filter equipped with a piezoelectric resonator. As shown in FIG. 6, electrodes 31a, 31b, 31c, 3
1d, 31e, 31f, 31g, 31h, 31i, 31
j are provided, among which electrodes 31b, 31f, 31h
and conductor patterns 3 on 31e, 31d, and 31j, respectively.
2a and 32b are connected.

FIG. 7 shows an equivalent electrical circuit diagram of the filter. Electrode 31a functions as input power, and electrode 3
1e functions as an output electrode, and 31g and 31i function as ground electrodes. Each piezoelectric resonator constitutes a ladder type circuit. [Fourth embodiment, FIGS. 8 and 9] The fourth embodiment has the conductor patterns 32a and 32 provided on the sealing substrate in the third embodiment.
b is modified as shown in FIG. FIG. 9 shows an equivalent electrical circuit diagram of the filter. Electrode 31a functions as an input electrode, electrode 31e functions as an output electrode, and electrodes 31c and 31i function as ground electrodes. Each piezoelectric resonator constitutes a ladder type circuit.

[Fifth Embodiment, FIGS. 10 to 12] In the fifth embodiment, a conductor pattern constituting a ladder type circuit is provided on the surface of a composite substrate. In FIG. 10, a composite substrate 40 is sandwiched between sealing substrates 50 from above and below. FIG. 11 is a plan view of the composite substrate 40. Vibration electrodes 42, 4 on the front and back surfaces
The piezoelectric substrate 41 provided with the vibrating electrodes 42, 4
Vibration in the energy trap type thickness shear vibration mode occurs in the portion where the electrodes 3 and 43 face each other and the portion where the vibrating electrodes 44 and 43 face each other. One end of each of the vibrating electrodes 42 and 44 and the center of the vibrating electrode 43 are lead electrodes 42a and 44.
a and 43a.

The insulating holding members 45, 46 have vibration space forming notches 45a, 45b and 46a, 46b, respectively.
, 46c, 46d are provided, and the front and back surfaces of both ends and the center of the piezoelectric substrate 41 are fixed from both sides with an adhesive,
keeping. Each piezoelectric substrate 41 is connected by the insulating holding members 45 and 46 to form one composite substrate 40. Conductive patterns 47a, 47b, 47c for electrically connecting the vibrating electrodes 42, 43, 44 of the piezoelectric substrate 41 to the upper surface of this composite substrate 40 to configure a ladder type circuit.
, 47d are provided. Further, electrodes 48a, 48b, 48c, 4 are provided on the rear and front end surfaces of the composite substrate 40.
8d, 48e, and 48f are provided (see Figure 10)
. The conductor patterns 47a, 47c, and 47d are electrically connected to electrodes 48a, 48e, 48c, and 48f, respectively.

On the other hand, the sealing substrate 50 has a recess 51 on the surface on which the vibration space is formed. The vibrating portion of the piezoelectric substrate 41 is formed by the notches 45a, 45b of the protection members 45, 46,
46a to 46d and the recess 51 of the sealing substrate 50 ensure a vibration space. In the laminated ladder filter, the electrodes 48a to 48f provided on the composite substrate 40 correspond to the electrodes 52a to 52f provided on the sealing substrate 50, respectively.
End surface electrodes (not shown) are provided on the rear and front end surfaces of the filter for electrical connection. Therefore, the electrode 52a is electrically connected to the vibrating electrode 42, and the electrode 52c
and 52f are electrically connected to the vibrating electrode 44, and the electrode 52
e is electrically connected to the vibrating electrode 43.

The filter thus obtained has a composite substrate 4
Since fine and complicated wiring can be formed on the surface of the 0, miniaturization is possible. For example, in the case of the piezoelectric substrate 41 provided with electrodes for thickness-shear vibration mode as in this embodiment, the thickness of the composite substrate 40 can be set to 0.1 mm or less. FIG. 12 shows an equivalent electrical circuit diagram of the filter. Electrodes 52a and 48a function as input electrodes, and electrodes 52a and 48a function as input electrodes.
c, 48c, 52f, 48f function as output electrodes,
Electrodes 52e and 48e function as ground electrodes. Each piezoelectric resonator constitutes a ladder type circuit.

[Other Embodiments] Note that the ladder-type piezoelectric component according to the present invention is not limited to the above embodiments, and can be modified in various ways within the scope of the gist. The vibration mode of the piezoelectric substrate is not limited to the thickness shear vibration mode, and may be other vibration modes, such as a thickness longitudinal vibration mode or a tuning fork vibration mode. In the case of the piezoelectric substrate 35 provided with the vibrating electrode 36 in the thickness longitudinal vibration mode as shown in FIGS. 13 and 14, the vibrating electrode 3 in the tuning fork vibration mode is
The case of a piezoelectric substrate 38 provided with 9 is shown.

Further, the conductor pattern provided on the sealing substrate 10 may be provided on the surface facing the vibration space, or may be provided on the two upper and lower sealing substrates 10, 10 divided into two. Furthermore, the sealing member can be set to any shape according to the specifications of the piezoelectric component,
For example, it may be box-shaped or cylindrical. In this case, after the piezoelectric substrate is housed in the sealing member,
It will be sealed with a lid or the like.

[0020]

Effects of the Invention As is clear from the above explanation, the ladder-type piezoelectric component of the present invention connects piezoelectric substrates by an insulating holding member and connects the piezoelectric substrates in a direction perpendicular to the thickness direction of the piezoelectric substrates. The piezoelectric component is printed because the conductive pattern provided on the surface of at least one of the sealing member and the composite substrate electrically connects the vibrating electrodes provided on the piezoelectric substrate. When attached to a wiring board, the piezoelectric substrate can be placed horizontally and vertically with respect to the printed wiring board, resulting in a ladder-type piezoelectric component that requires only a small component mounting space.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing a first embodiment of a ladder-type piezoelectric component according to the present invention.

FIG. 2 is a perspective view showing the appearance of the ladder-type piezoelectric component of the first embodiment.

FIG. 3 is an equivalent electrical circuit diagram of the ladder-type piezoelectric component of the first embodiment.

FIG. 4 is a plan view of a sealing substrate used in a second embodiment of the ladder-type piezoelectric component according to the present invention.

FIG. 5 is an equivalent electric circuit diagram of the ladder-type piezoelectric component of the second embodiment.

FIG. 6 is a plan view of a sealing substrate used in a third embodiment of the ladder-type piezoelectric component according to the present invention.

FIG. 7 is an equivalent electrical circuit diagram of a ladder-type piezoelectric component according to a third embodiment.

FIG. 8 is a plan view of a sealing substrate used in a fourth embodiment of the ladder-type piezoelectric component according to the present invention.

FIG. 9 is an equivalent electrical circuit diagram of a ladder-type piezoelectric component according to a fourth embodiment.

FIG. 10 is an exploded perspective view showing a fifth embodiment of the ladder-type piezoelectric component according to the present invention.

FIG. 11 is a plan view of a composite substrate used in the ladder-type piezoelectric component shown in FIG. 10.

[Fig. 12] Equivalent electrical circuit diagram of the ladder-type piezoelectric component of the fifth embodiment

FIG. 13 is a partially exploded perspective view showing a modification of the composite substrate of the ladder-type piezoelectric component according to the present invention.

FIG. 14 is a partially exploded perspective view showing another modification of the composite substrate of the ladder-type piezoelectric component according to the present invention.

[Explanation of symbols]

1... Piezoelectric substrates 2, 3... Vibration electrodes 5, 6... Insulating holding members 5a, 6a, 6b... Vibration space forming notches 9... Composite substrate 10... Sealing substrate (sealing member) 11... Recesses 15a, 15b, 16a, 16b...conductor pattern 25...
End surface electrode 30... Sealing substrate (sealing member) 32a, 32b, 33a, 33b... Conductor pattern 35,
38... Piezoelectric substrates 36, 39... Vibrating electrodes 40... Composite substrate 41... Piezoelectric substrates 42, 43, 44... Vibrating electrodes 45, 46... Insulating holding members 45a, 45b, 46a, 46b, 46c, 46d... Vibration space Forming notches 47a, 47b, 47c, 47d...conductor pattern 50...
Sealing substrate (sealing member) 51... recess

Claims (1)

[Claims] 1. A piezoelectric substrate with vibrating electrodes provided on the front and back surfaces, the piezoelectric substrate being held from both sides in the thickness direction, and the piezoelectric substrates being connected to each other in the thickness direction of the piezoelectric substrate. An insulating holding member constituting a composite substrate having a plate thickness in a vertical direction, and a sealing member joining the composite substrate to form a vibration space, and electrically connecting the vibrating electrode provided on the piezoelectric substrate. 1. A ladder-type piezoelectric component, characterized in that a conductor pattern connected to the substrate to form a ladder-type circuit is provided on at least one surface of the sealing member or the composite substrate.