JPH044603A - Chip type piezoelectric component - Google Patents

Abstract

PURPOSE:To miniaturize a piezoelectric component by employing a chip type piezoelectric component laminated and sealed by a protection base to form for at least one piezoelectric resonator formed with a couple of opposite electrodes on a piezoelectric substrate. CONSTITUTION:Two piezoelectric resonators 1a, 1b are formed to have an identical electrode structure. Only a couple of opposite electrodes 3a, 3b are formed to a piezoelectric substrate 2 in the piezoelectric resonators 1a, 1b constituted of such the electrode structure, so the size is smaller than a conventional piezoelectric resonator, e.g. nearly 1mm in the thickness and 5mm in the length is required for formation. An intermediate protection base 7 with a recessed part 8 for space forming formed thereto is interposed between the two piezoelectric resonators 1a, 1b of the structure above and the two piezoelectric resonators 1a, 1b and three protection bases 7, 9, 11 are sequentially laminated. Thus, without cascade connection of plural pairs of opposite electrodes to a long piezoelectric substrate, plural numbers of small piezoelectric resonators 1a, 1b are employed to constitute a filter having a same equivalent circuit as that of a conventional filter.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a chip-type piezoelectric component useful as a filter, trap, or discriminator.

[Prior Art and Problems to be Solved by the Invention] Conventionally, piezoelectric components shown in FIGS. 7 and 8 have been known as filters that utilize the thickness shear vibration mode. FIG. 7 is an exploded perspective view of a conventional piezoelectric component, and FIG. 8 is a sectional view of the piezoelectric component of FIG.

The piezoelectric resonator of the thickness-shear vibration mote includes a long flat piezoelectric substrate (72), a plurality of pairs of opposing electrode portions (73a) (73b) formed on one surface of the piezoelectric substrate (72), An input extraction electrode part (74) and an output extraction electrode part (75) extending from the opposite electrode parts (73a) at both ends, and the opposite electrode part (73) on the other surface of the piezoelectric substrate (72).
It is configured with a grounding common electrode portion (76) formed at a location corresponding to a) (73b). The size of the piezoelectric resonator (71) having the above electrode structure is the same as that of the piezoelectric substrate (72).
) Plural pairs of opposing electrode portions (73a) (73
b), so the thickness is usually about 1.2 mm and the length is about 8 mm.

Such a piezoelectric resonator (71) is mounted on mounting step portions (79) formed at both ends of the four housing portions (78) of the lower case (77).
It is placed and housed in. An input/output lead electrode part (74) is located on the end surface of the lower case (77) from the mounting stage part (79).
(75) and connection electrode portions (80) and (81) conductive to each other.
) is formed. A convex portion (82) that contacts the common electrode portion (76) is formed in the housing recess (78). A connecting electrode portion (83) is formed on the convex portion (82) and extends to the end face of the lower case (77>) and is electrically connected to the external earthing electrode (76).

The piezoelectric resonator (71) accommodated in the accommodation recess (78) of the lower case (77) is sealed with a flat protective substrate (84).

Further, the connection electrode portions (80) and (81) are, respectively,
The external electrodes for human power (85) and the external electrodes for output (86) on both sides of the lower case (77) and the protection board (84) are electrically connected.

Further, a connection electrode portion (83) extending from the convex portion (82)
is electrically connected to the grounding external electrode part (87) formed between the input/output external electrodes (85) (ge).

Such a piezoelectric component has connection electrode parts (80) (81,)
Since it is connected to the input/output external electrode (85) (8B) or the plurality of counter electrode parts (73a) (B3b) through the Can be configured. However, in order to improve filter characteristics, it is necessary to form a plurality of opposing electrode portions (73a) (73b) in series on a long piezoelectric substrate (72). In addition, a long piezoelectric resonator (7
1) is accommodated in the accommodation recess (78) of the lower case (77),
Since it is sealed with a protective substrate (84), the piezoelectric component becomes even larger, for example, 4 mm x 10 mm x 1, 8 m.
The size is about m. Furthermore, as piezoelectric components become larger, carrier tapes with larger widths are required.

Therefore, an object of the present invention is to provide a chip-type piezoelectric component that can be miniaturized using a piezoelectric resonator in the thickness-shear vibration mode.

[Means for Solving the Problems] The present invention provides a piezoelectric resonator in a thickness shear vibration mode in which a counter electrode is formed on a piezoelectric substrate, and a piezoelectric resonator in which the piezoelectric resonator is sealed,
The piezoelectric component has a protective substrate on which an external electrode is formed in conduction with the counter electrode, and at least one piezoelectric resonator in which a pair of counter electrodes are formed on the piezoelectric substrate is laminated with the protection substrate. The above problem is solved by a sealed chip-type piezoelectric component.

[Function] In the present invention, since a pair of opposing electrodes are formed on the piezoelectric substrate, the length of the piezoelectric resonator can be reduced. Further, since the piezoelectric resonator having a small length is laminated and sealed with a protective substrate, the protective substrate only needs to have a size suitable for the piezoelectric resonator. Therefore, the size of the protective substrate can be made smaller than that of a conventional protective substrate having a housing recess.

Furthermore, even in the case of a piezoelectric resonator having a pair of opposing electrode parts, it is possible to sequentially laminate and seal a plurality of piezoelectric resonators and a protective substrate, and connect the opposing electrodes of the plurality of piezoelectric resonators sequentially via the electrodes. By connecting them, it is possible to configure an equivalent circuit similar to the case where a plurality of pairs of opposing electrode portions are formed on a piezoelectric substrate.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is an exploded perspective view showing a chip-type piezoelectric component as an embodiment of the present invention, FIG. 2 is a sectional view showing the chip-type piezoelectric component shown in FIG. 1, and FIG. - It is an exploded perspective view showing a knob-shaped piezoelectric component. In this example, two piezoelectric resonators (
A filter using (lb) is shown.

The two piezoelectric resonators (la) and (lb) are each formed with the same electrode structure. That is, the two piezoelectric resonators (la) and (lb) include a piezoelectric substrate (2) and a pair of opposing electrode portions (3a) and (3b) formed opposite to one surface of this piezoelectric substrate (2). and a pair of opposing electrodes (
3a) An input extraction electrode part (4a) and an output extraction electrode part (4b) extending from (3b) to both ends, and the pair of opposing electrode parts (3a) on the other surface of the piezoelectric substrate (2). (
3b), and a grounding lead electrode part (6) extending from the common electrode part (5) to one end.

A piezoelectric resonator (Ia) (lb) with such an electrode structure is
A pair of opposing electrode parts (3a) (3b) on the piezoelectric substrate (2)
Since the piezoelectric resonator is not formed with L, .
It can be formed to about mm.

In this example, two piezoelectric resonators (1a) (1
An intermediate protective substrate (7) formed with four space-forming parts (8) is interposed between b). Moreover, the two piezoelectric resonators (Ia) (Ib) have opposing electrode parts (3a) (3b)
An input extraction electrode part (4a) and an output extraction electrode part (4b) extending from the input electrode part (4b) are arranged so as to face each other on both sides. Furthermore, two piezoelectric resonators (la) (lb
) are provided with upper and lower protective substrates (9) on which four parts (10) and (12) for space formation are formed respectively on the surface of the common electrode part (5).
(11) are stacked. That is, two piezoelectric resonators (la) (lb) and three protection substrates (7) (9) (
11) are sequentially laminated.

And, on one side of the lower protection board (9), a first
An input external electrode part (13) electrically connected to the input extraction electrode part (4a) of the first piezoelectric resonator (1a) is formed on the other side, and a grounding part of the first piezoelectric resonator (1a) is formed on the other side. A grounding external electrode part (14) electrically connected to the extraction electrode part (6) is formed. Further, on one side surface of the intermediate protection substrate (7), the output lead electrode part (4b) of the first piezoelectric resonator (1a) and the input lead electrode part of the second piezoelectric resonator (1b) are provided. Connection external electrode part (15) electrically connected to the electrode part (4a)
is formed. Further, on one side surface of the upper protection substrate (11), an output external electrode part (16
) is formed, and a second piezoelectric resonator ( ) is formed on the other side surface.
A grounding external electrode part (17) electrically connected to the grounding extraction electrode part (6) of 1b) is formed.

In addition, the piezoelectric resonators (la) (lb) and each protection board (7)
(9) The contact part with (11) is the external electrode part (13) (
14), (15) (1B) They are joined and sealed by a conductive adhesive (18) that is electrically connected to (17). Piezoelectric resonators (Ia) (lb) and each protection board (force (9) (11)
Filler such as silicone resin (19
) is filled.

Further, as shown in FIG. 1 and FIG.
) are sealed with protective substrates (20) and (21). An input electrode part (24) electrically connected to the external electrode part (13) for human power is provided at a part of the corner of the protection board (20) (21).
), the output electrode part (
25), and the external earth electrode part (14) (1, 7)
A ground electrode portion (2B) (27) electrically connected to the ground electrode portion (2B) (27) is formed.

Therefore, the input electrode part (24) of the protection board (20) (21)
) to the input/output extraction electrodes (4a) (4b) of the first piezoelectric resonator (1a), and the intermediate protection substrate (7).
) is formed on one side surface of the connecting external electrode part (15
), the input/output extraction electrode part of the second piezoelectric resonator (1b) (
4a) After passing through (4b), the protective board (20) (21)
can be output from the output electrode section (25). Also, the earth electrode part (2B) (2
7), it is possible to ground the grounding lead electrode part (6) of the first piezoelectric resonator (1a) and the grounding lead electrode part (6) of the second piezoelectric resonator (1b). .

In a chip-type piezoelectric component having such a structure, a pair of opposing electrode sections (3a) (3
b) A small piezoelectric resonator (], a) (l
By using a plurality of items b), a filter having the same equivalent circuit as the conventional one can be constructed. In addition, due to the laminated structure, multiple piezoelectric resonators (la) (lb) are connected to the protective substrate (7) (9
) (11), the chip-type piezoelectric component can be downsized to, for example, about 3 mm x 5 mm x 2 mm.

In the above embodiment, two piezoelectric resonators (Ia) (Ib)
However, a trap or a discriminator may be constructed using one piezoelectric resonator.

FIG. 4 is an exploded perspective view of essential parts showing another embodiment of the chip mold press and mold parts of the present invention. Note that the same elements as in the chip-type piezoelectric component shown in FIGS. 1 to 3 are given the same reference numerals.

In this example, by stacking the upper and lower protective substrates (9) and (11), both sides of one piezoelectric resonator (1) having the same electrode structure as above are sealed, thereby forming a discriminator. . That is, the piezoelectric resonator (1) in the thickness shear vibration mode includes a piezoelectric substrate (2), a pair of opposing electrode parts (3a) (3b), and an input/output extraction electrode part (4a) ( 4b), a common electrode part (5), and a grounding extraction electrode part (6). Upper and lower protective substrates (9) are laminated and sealed on both sides of this piezoelectric resonator (1).
On one side of the piezoelectric resonator (1), there is an external electrode section for human power (13
) is formed. Further, on the other side of the upper protection substrate (11), an output extraction electrode part (
4b) is formed, and the other side of the lower protection board (11) is formed with an output external electrode part (I6) electrically connected to the grounding lead electrode part (6) of the piezoelectric resonator (1). A grounding external electrode section (14) is formed.

The chip-type piezoelectric component of this embodiment has one piezoelectric resonator (1) in addition to the effects of the chip-type piezoelectric component of the previous embodiment.
and the two protective substrates (9) and (11) are stacked, so the height can be reduced and the size can be reduced.

Note that the electrode structure is not particularly limited as long as the vibration mode of the piezoelectric resonator is the thickness shear vibration mode.

FIG. 5(A) is a perspective view showing one side of a piezoelectric resonator in another embodiment of the present invention, and FIG. 5(B) is a perspective view of FIG. 5(A).
FIG. 3 is a perspective view showing the other surface of the piezoelectric resonator.

The piezoelectric resonator (31) includes a piezoelectric substrate (32), a pair of opposing electrode portions (33a) (33b) on both sides of the piezoelectric substrate (32), and a pair of opposing electrode portions (33a) (33b) that face each other across the thickness of the piezoelectric substrate (32). The input electrode part (34a) and the output electrode part (34a) extend in opposite directions from the opposing electrode parts (33a) and (33b), respectively.

When using a piezoelectric resonator (31) having such an electrode structure, as in the above embodiment, a pair of opposing electrode portions (3a) (3b) are provided on the − side of the piezoelectric substrate (2). There is no need to form a piezoelectric resonator, and the counter electrode parts (33a) and (33b) can be opposed to each other through the thickness of the piezoelectric substrate (32), so the length of the piezoelectric resonator (31) can be further reduced.
Chip-type piezoelectric components can be further downsized.

The chip-type piezoelectric component of the present invention only needs to have at least one thickness-shear vibration mode piezoelectric resonator formed with a pair of opposing electrode parts, and by using a plurality of piezoelectric resonators, filter characteristics and trap characteristics can be obtained. can be increased.

Further, the protective substrate may be in the form of a flat plate without four parts for forming a space. Even when such a flat protective substrate is used, the space can be secured by the thickness of the conductive adhesive (18) that joins the abutting portions of the piezoelectric resonator and the protective substrate.

The chip-type piezoelectric component of the present invention can be manufactured, for example, as follows. FIG. 6 shows the manufacturing process of the chip-type piezoelectric component shown in FIGS. 1 to 3, FIG. 6(A) is an exploded perspective view showing the first lamination step, and FIG. 6(B) is FIG. 6(C) is a cross-sectional view showing the cutting process, FIG. 6(C) is a cross-sectional view showing the filling process, FIG. 6(D) is an exploded perspective view showing the second lamination process, and FIG. 6(E) is the electrode part formation. It is a perspective view showing a process.

The manufacturing method of this example includes two elongated piezoelectric resonators (41a
) (41b) and three long protective substrates (47) (4
9) A first lamination step (A) of laminating (51), a cutting step (B) of cutting the laminate (67) obtained in the first lamination step (^), and a cut chip piece. (68), a second lamination step (D) of laminating the protective substrate (20) (21) on the end face of the chip piece (68), and a second lamination step (D) of laminating the protective substrate (20) (21) on the end face of the chip piece (68); (21) and an electrode part forming step (E) of forming an electrode part on the end face.

The two piezoelectric resonators (41
a) (41b) are two long piezoelectric substrates (42a)
(42b) and these piezoelectric substrates (42a) (42
A pair of opposing electrode parts (43a) (43b) formed in the longitudinal direction of one surface of b) and an input/output extraction electrode part (4
4a) (44b) and piezoelectric substrates (42a) (42b)
) is formed in the longitudinal direction of the other surface of the common electrode part (45).
and a grounding lead electrode part (46).

Further, in the longitudinal direction of the elongated intermediate protection substrate (47), concave S (4g) for space formation is formed on both sides, and a space is formed in the longitudinal direction of the elongated upper and lower protection substrates (49) (51). Concave grooves (50) and (52) are also formed.

In the longitudinal direction of each protection board (47) (49) (51), an input/output external electrode part ( 53) (5B) and connection external electrode part (55
), and external earthing electrode parts (54) and (57) that are electrically connected to the earthing extraction electrode part (46) are formed. These input/output external electrode parts (53) (5B), connection external electrode parts (55), and grounding external electrode parts (54)
(57) is coated with a conductive adhesive (18). In order to prevent this conductive adhesive (18) from leaking inward due to capillary action and causing a short circuit, the conductive adhesive (18) is applied by curing the conductive adhesive applied once and then printing additional conductive adhesive. It is formed. In addition, as mentioned above, each protection board (47) (49) (51) has a concave groove (
48,) (50) (52) are formed, so
It is possible to reliably prevent short-circuit defects due to capillary phenomenon.

In the first lamination step (^), the two piezoelectric resonators (41a) (41b) and the upper and lower protective substrates (49) (51) are laminated with an intermediate protective substrate (47) interposed between them to form a laminate ( 6
7).

In the cutting step (B), a large number of chip pieces (68) are obtained by sequentially cutting the elongated laminate (67) in a direction perpendicular to the longitudinal direction.

In the filling step (C), the piezoelectric resonator (
418) (41b) and protective board (47) (49)
Filler (1) such as silicone resin in the space between (51)
9) Fill.

Since the chip piece (68) is thin, this filling operation can be performed by applying silicone resin or the like and curing it. Chip piece (68) filled with filler (19)
) has the cross-sectional structure shown in FIG. 3 above.

In the second lamination step (D), recesses (22) are formed on both end faces of the chip piece (68) obtained in the filling step (C), and the protective substrates (20) and (21) are laminated with an adhesive. .

In addition, on a part of the corner of the surface of each protective substrate (20) (21), by masking the area other than the corner part and forming a thin film by a thin film forming method such as sputtering, a base electrode part for input (24a) is formed. ), output base electrode part (25a) and ground base electrode part (26a) (2
7a) is formed.

In the electrode forming step (E), each base electrode is formed on the side end surface of the chip component obtained in the second lamination step (D), that is, on a part of the corner of the two protective substrates (20) and (21). Parts (24a) (25a) (26a) (27a)
The same masking and sputter link as described above is applied to the side end surfaces between the input base electrode part (24a), the output base electrode part (25a), and the ground base electrode part (26a).
) (27a) is formed. Next, the plating process is carried out.
Each base electrode part (24a) (25a) (26a) (
By forming the manual electrode part (24), the output electrode part (25), and the ground electrode parts (26) and (27) in 27a), the chip-type piezoelectric component shown in FIGS. 1 to 3 can be obtained.

Note that preferred embodiments of the present invention are as follows.

A piezoelectric component having a thickness-shear vibration mode piezoelectric resonator having a pair of opposing electrodes formed on a piezoelectric substrate, and a protective substrate sealing the piezoelectric resonator and having an external electrode electrically connected to the opposing electrode. The two piezoelectric resonators are laminated and sealed with a protective substrate via an intermediate protective substrate, and each protective substrate has an external electrode portion that is electrically connected to the opposing electrode portions of the two piezoelectric resonators. A chip-type piezoelectric component made of

[Effects of the Invention] As described above, according to the chip-type piezoelectric component of the present invention, at least one piezoelectric resonator on which a pair of opposing electrodes are formed is laminated and sealed with the protective substrate. Even piezoelectric resonators in thickness-shear vibration mode can be miniaturized.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing a chip-type piezoelectric component according to an embodiment of the present invention, FIG. 2 is a sectional view showing the chip-type piezoelectric component shown in FIG. 1, and FIG. 3 is a chip-type piezoelectric component shown in FIG. 1. FIG. 4 is an exploded perspective view showing the main parts of another embodiment of the chip-type piezoelectric component of the present invention. FIG. 5(A) is an exploded perspective view of the piezoelectric resonator in another embodiment of the present invention. A perspective view showing one side, FIG. 5(B) is a perspective view showing one side.
FIG. 6 is a perspective view showing the other side of the piezoelectric resonator, and FIG. 6 shows the manufacturing process of the chip-type piezoelectric component shown in FIGS. 1 to 3, and FIG. An exploded perspective view showing
FIG. 6(B) is a cross-sectional perspective view showing the cutting process, FIG. 6(C)
) shows a cross-sectional view showing the filling process, FIG. 6(D) shows an exploded perspective view showing the second lamination process, and FIG. 6(E) shows a perspective view showing the electrode part forming process. FIG. 7 is an exploded perspective view of a conventional piezoelectric component, and FIG. 8 is a sectional view of the piezoelectric component of FIG. (1) (la) (lb) - piezoelectric resonator, (2) -.
・Piezoelectric substrate, (3a) (3b)... Counter electrode, (7) (9) (11) (20) (21)... Protective substrate, (13) (+4) (15) (1B) (17) (2
4) (25) (2B) (27)... External electrode section patent applicant Representative Murata Manufacturing Co., Ltd. Attorney Patent attorney Hoe 1) Mitsuru! :l jcl jD Figure 3, Figure 4 Figure 5 (A) Figure 6 (A) Figure-1 (B) Figure 6-2 C)

Claims (1)

[Claims] A piezoelectric component comprising a thickness shear vibration mode piezoelectric resonator in which a counter electrode is formed on a piezoelectric substrate, and a protective substrate that seals the piezoelectric resonator and has an external electrode electrically connected to the counter electrode. . A chip-type piezoelectric component, wherein at least one piezoelectric resonator having a pair of opposing electrodes formed on the piezoelectric substrate is laminated and sealed with the protective substrate.