JPH05335871A - Electronic component - Google Patents

Abstract

PURPOSE:To obtain the electronic component with high electric connection reliability for an external electrode and an internal electrode against an external stress. CONSTITUTION:Throughholes 27a, 28a connecting electrically auxiliary electrodes 11a, 11b provided to a vibration base 29 and external electrodes 30, 31 provided to an end of a laminator 29 are provided to an end of the laminator 29. The external electrodes 30, 31 are connected respectively to auxiliary electrodes 11a, 11b at the end face of the laminator 29 and connected respectively via the throughholes 27a, 28a. After the piezoelectric component is mounted on a printed circuit board, a strong external stress is applied, the external electrodes 30, 31 are exfoliated from the end face of the laminator 29 and the electric connection between the external electrodes 30, 31 and the auxiliary electrodes 11a, 11b is lost, the electric connection between the external electrodes 30, 31 and the auxiliary electrodes 11a, 11b is compensated by the throughholes 27a, 28a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to electronic parts, especially ICs.
The present invention relates to a thin piezoelectric component used for a card oscillator or the like.

[0002]

2. Description of the Related Art For example, a piezoelectric component used for an oscillator of an IC card is composed of a piezoelectric member having vibrating electrodes on the front and back surfaces and an insulating holding member for holding the piezoelectric member from both sides. It is known that the vibrating substrate is formed, and the vibrating substrate is sandwiched between insulating sealing substrates to form a laminated body. External electrodes are formed on both ends of the laminate by thin film forming means such as sputtering or vapor deposition. The external electrode is electrically connected to the internal electrode exposed on the end surface of the laminated body.

By the way, this type of piezoelectric component has a small thickness and is apt to bend due to external stress. The printed wiring board on which this piezoelectric component is mounted is also usually set to have a small thickness. Therefore, when a strong external stress is applied to the printed wiring board on which the piezoelectric component is mounted, the piezoelectric component and the printed wiring board are bent, and mechanical stress is applied to the external electrodes of the piezoelectric component soldered to the printed wiring board. Due to this mechanical stress, there is a risk that a gap is created at the connecting portion between the external electrode and the internal electrode on the end surface of the laminate, and the electrical connection between the external electrode and the internal electrode is lost.

Therefore, an object of the present invention is to provide an electronic component having high reliability of electrical connection between an external electrode and an internal electrode against external stress.

[0005]

In order to solve the above problems, an electronic component according to the present invention is provided with (a) a laminate comprising at least an insulating member and (b) an end portion of the laminate. An external electrode that is provided; (c) an internal electrode that is disposed inside the laminate and that is electrically connected to the external electrode at an end face of the laminate; and (d) that is provided in the laminate, A through hole electrically connected to the external electrode and the internal electrode.

Since the through hole is strong against mechanical stress, it is not easily deformed even when a strong external stress is applied to the piezoelectric component or the printed wiring board, and peeling does not easily occur at the connection portion with the external electrode or the internal electrode. Therefore, even if external stress is applied to the printed wiring board on which the electronic components are mounted and a gap is created in the connection portion between the external electrode and the internal electrode on the end face of the laminate, the electrical connection between the external electrode and the internal electrode is compensated by the through hole. It

Further, by providing the through hole in the laminated body, the mechanical strength of the electronic component itself is increased, and the electronic component itself is less likely to bend against external stress. Further, if one end of the through hole provided in the laminated body is exposed to the laminated body mounting surface, the internal electrode provided in the electronic component and the conductor provided in the printed wiring board are provided. The conduction path through the through hole is short, so that it is less likely to be affected by external stress.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of electronic parts according to the present invention will be described below with reference to the accompanying drawings. In each embodiment, a piezoelectric component will be described as an example of the electronic component. Further, in each embodiment, the same parts and the same parts are designated by the same reference numerals. [First Embodiment, FIGS. 1 to 6] As shown in FIG. 1, the piezoelectric component of the first embodiment includes a piezoelectric substrate 1 having vibrating electrodes 2 and 3 on the front and back surfaces, and the piezoelectric substrate 1. A single vibrating substrate 12 is composed of insulating holding members 5 and 7 for holding
Further, the vibration substrate 12 is sandwiched between the insulating sealing substrates 20,
It is of a laminated structure type with a closed vibration space. The piezoelectric substrate 1 is made of a ceramic material such as PZT,
The vibrating electrodes 2 and 3 are made of Ag or the like. The holding members 5 and 7 are provided with vibration space forming recesses 6 and 8, respectively. The piezoelectric substrate 1 and the holding members 5 and 7 are integrally fixed to each other via an adhesive to form a vibration substrate 12. Vibration board 1
Auxiliary electrodes 11 a and 11 b electrically connected to the vibrating electrodes 2 and 3 are provided on the upper surface of 2. The sealing substrate 20 is fixed to the upper and lower sides of the vibrating substrate 12 with an adhesive to form a laminated body 29 having a sealed vibrating space.
The vibrating electrodes 2, 3 and the auxiliary electrode 11 are provided on the end surface of the laminated body 29.
One end of a and 11b is exposed. Sealing substrate 20
Has a recess 20a on the surface on which the vibration space is formed, and conductors 21a and 21b on the surface on the reflection side.

Next, as shown in FIG.
Through holes 25a, 25b at both ends of
26a and 26b are formed. Further, as shown in FIG. 3, external electrodes 30 and 31 are formed on both ends of the laminated body 29 by thin film forming means such as sputtering or vapor deposition.
At this time, the external electrodes 30 and 31 are the vibrating electrodes 2 and 3 and the auxiliary electrodes 11a and 11b exposed on the end faces of the laminated body 29.
Are electrically connected to each other and cover the conductors 21a and 21b provided on the sealing substrate 20. After that, by filling the through holes 25a to 26b with a conductive material, through holes 27a, 27b, 28a, for improving the electrical connection reliability between the auxiliary electrodes 11a, 11b and the external electrodes 30, 31 are formed. 28b is formed. The lower ends of the through holes 27a to 28b are exposed on the mounting surface of the laminated body 29, and are further exposed on the surfaces of the external electrodes 30 and 31.

FIG. 4 is a vertical sectional view of the piezoelectric component thus obtained. Through holes 27a, 27b, 28a, 2
8b are auxiliary electrodes 11a and 11b and an external electrode 3 respectively.
It is electrically connected to 0 and 31. As shown in FIG. 5, this piezoelectric component is mounted on conductors 35a and 35b provided on the surface of the printed wiring board 34 via solders 36a and 36b. When strong external stress is applied after the piezoelectric component is mounted on the printed wiring board 34, as shown in FIG.
4, the external electrodes 30 and 31 of the piezoelectric component are mechanically stressed and the external electrodes 30 and 31 are deformed, and a gap 38 is formed at the interface between the external electrodes 30 and 31 and the end surface of the laminate 29.
a, 38b may occur. In this case, there is no electrical connection between the external electrodes 30, 31 and the auxiliary electrodes 11a, 11b and the vibrating electrodes 2, 3 on the end faces of the laminate. However, since the through holes 27a to 28b are strong against mechanical stress, they are unlikely to be deformed even when a strong external stress is applied,
Peeling does not easily occur at the connection portions with the external electrodes 30 and 31 and the auxiliary electrodes 11a and 11b. On the other hand, since the electric connection between the vibrating electrodes 2 and 3 and the auxiliary electrodes 11a and 11b is made inside the laminated body 29, even if a strong external stress is applied, it is hardly affected. Therefore, the external electrodes 30, 31
The electrical connection between the auxiliary electrodes 11a and 11b and the auxiliary electrodes 11a and 11b, that is, the electrical connection between the external electrodes 30 and 31 and the vibrating electrodes 2 and 3 is compensated by the through holes 27a to 28b. As a result, it is possible to obtain a piezoelectric component having excellent connection reliability between the external electrodes 30 and 31 and the vibrating electrodes 2 and 3.

Further, the through hole 27 is provided at the end of the laminated body 29.
By providing a to 28b, the mechanical strength of the piezoelectric component itself is increased, and the piezoelectric component itself is less likely to bend against external stress. Second Embodiment, FIGS. 7 and 8 As shown in FIGS. 7 and 8, the piezoelectric component of the second embodiment is an auxiliary electrode electrically connected to the vibrating electrodes 2 and 3 on the lower surface of the vibrating substrate 12. 13a, 13
b is provided. Then, through holes 40a, 40b, 41a, 4 are previously formed at both ends of the lower sealing substrate 20.
1b is provided.

The sealing substrates 20 are fixed to the upper and lower sides of the vibration substrate 12 with an adhesive to form a laminated body 29 having a closed vibration space. One end of each of the vibrating electrodes 2 and 3 and the auxiliary electrodes 13a and 13b is exposed on the end surface of the laminated body 29, and is electrically connected to the external electrodes 30 and 31. In the laminated state, the through holes 40a to 41b are respectively the auxiliary electrodes 13a,
13b and the external electrodes 30 and 31 are electrically connected.
The lower ends of the through holes 40a to 41b are exposed on the mounting surface of the laminated body 29 and covered with the external electrodes 30 and 31.

The piezoelectric component thus obtained has the same operation and effect as the piezoelectric component of the first embodiment. [Third Embodiment, FIGS. 9 and 10] As shown in FIGS. 9 and 10, the piezoelectric component of the third embodiment is an auxiliary device electrically connected to the vibrating electrodes 2 and 3 on the upper and lower surfaces of the vibrating substrate 12. Electrode 14
a and 14b are provided. Through holes 42a, 42b, 43a, 4 are previously formed at both ends of the lower sealing substrate 20.
3b is provided. Further, in the vibration substrate 12, through holes 44a and 44b are provided at the positions of the auxiliary electrodes 14b provided on the upper surface.

By fixing the sealing substrates 20 above and below the vibrating substrate 12 with an adhesive, a laminated body 29 having a sealed vibrating space is formed. In the stacked state, the through holes 43a and 44a and 43b and 44b are electrically connected to form an integral through hole, and are electrically connected to the external electrode 31 and the auxiliary electrode 14b. Through hole 4
2a and 42b are electrically connected to the external electrode 30 and the auxiliary electrode 14a. Through holes 42a, 42b and 43
The lower end portions of a and 43b are exposed on the mounting surface of the laminated body 29 and covered with the external electrodes 30 and 31.

The piezoelectric component thus obtained has the same operation and effect as the piezoelectric component of the first embodiment. [Fourth Embodiment, FIGS. 11 and 12] As shown in FIGS. 11 and 12, the piezoelectric component of the fourth embodiment has auxiliary electrodes 15 electrically connected to the vibrating electrodes on the upper and lower surfaces of the vibrating substrate 12.
a and 15b are provided. The through holes 45a, 4 are previously formed at the positions of the conductors 21a provided on the lower sealing substrate 20.
5b is provided. Through holes 46a and 46b are also provided in advance at the position of the conductor 21b provided on the upper sealing substrate 20.

By fixing the sealing substrates 20 above and below the vibrating substrate 12 with an adhesive, a laminated body 29 having a sealed vibrating space is formed. In the stacked state, the through holes 45a and 45b are electrically connected to the external electrode 30 and the auxiliary electrode 15a. The through holes 46a and 46b are electrically connected to the external electrode 31 and the auxiliary electrode 15b. The lower ends of the through holes 45a and 45b are the laminated body 29.
Of the through-holes 46a and 46b are exposed on the mounting surface and are covered with the external electrodes 30, and the upper ends of the through holes 46a and 46b are exposed on the upper surface of the laminated body 29 and are covered with the external electrodes 31.

The piezoelectric component thus obtained has the same action and effect as the piezoelectric component of the first embodiment. [Fifth Embodiment, FIG. 13] As shown in FIG. 13, the piezoelectric component of the fifth embodiment has a piezoelectric substrate 51 having vibrating electrodes 52a and 52b on the front and back surfaces, and a piezoelectric substrate 51 for accommodating the piezoelectric substrate 51. It is composed of an insulating case 55 having a recess 55a and an insulating sealing lid 56. The piezoelectric substrate 51 is horizontally housed in the recess 55 a of the insulating case 55, and
The a and 52b are connected to the extraction electrodes 53a and 53b formed on the insulating case 55 via solder 54.
The sealing lid 56 is fixed to the opening end of the insulating case 55 with an adhesive, and is a laminated body 59 having a vibration space that is sealed together with the insulating case 55 and the piezoelectric substrate 51.
One end of each of the extraction electrodes 53a and 53b is exposed on both end surfaces of the laminated body 59 and is electrically connected to the external electrodes 61 and 62 provided at the end of the laminated body 59, respectively.

Through holes 57 and 58 are formed at both ends of the laminated body 59, respectively, and lead electrodes 53a and 53b are formed.
The electrical connection reliability between the external electrodes 61 and 62 is improved. The piezoelectric component thus obtained has the same operation and effect as the piezoelectric component of the first embodiment.

[Other Embodiments] The electronic component according to the present invention is not limited to the above-mentioned embodiments, but can be variously modified within the scope of the gist thereof. In particular, although the above embodiment has been described by taking the piezoelectric component as an example, the invention is not necessarily limited to this, and other types of electronic components may be used.

[0020]

As is apparent from the above description, according to the present invention, since the through hole electrically connected to the external electrode and the internal electrode is provided in the laminated body, the piezoelectric component is mounted. Even if a strong external stress is applied to the printed wiring board and the electrical connection between the external electrode and the internal electrode is lost at the end surface of the laminate, the electrical connection between the external electrode and the internal electrode is compensated by the through hole. As a result, an electronic component having excellent connection reliability between the external electrode and the internal electrode can be obtained. In addition, the through holes provided in the laminated body increase the mechanical strength of the electronic component itself, and it is possible to obtain the one that is not easily bent by external stress.

Further, if one end of the through hole provided in the laminated body is exposed on the laminated body mounting surface,
Since the conduction path through the through hole between the internal electrode provided on the electronic component and the conductor provided on the printed wiring board is short, it is less likely to be affected by external stress. The electrical connection reliability between the printed wiring board and the printed wiring board can be further improved.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a first embodiment of an electronic component according to the present invention.

FIG. 2 is a perspective view showing a state after stacking of the electronic component shown in FIG.

FIG. 3 is a perspective view showing the external appearance of the electronic component shown in FIG.

FIG. 4 is a vertical cross-sectional view taken along line X-X ′ of FIG.

5 is a vertical cross-sectional view showing a state in which the electronic component shown in FIG. 1 is mounted on a printed wiring board.

6 is a vertical cross-sectional view for explaining a state where external stress is applied to the printed wiring board on which the electronic component shown in FIG. 1 is mounted.

FIG. 7 is an exploded perspective view showing a second embodiment of the electronic component according to the present invention.

8 is a vertical cross-sectional view of the electronic component shown in FIG.

FIG. 9 is an exploded perspective view showing a third embodiment of the electronic component according to the present invention.

10 is a vertical cross-sectional view of the electronic component shown in FIG.

FIG. 11 is an exploded perspective view showing a fourth embodiment of the electronic component according to the present invention.

FIG. 12 is a vertical sectional view of the electronic component shown in FIG.

FIG. 13 is a vertical sectional view showing a fifth embodiment of the electronic component according to the present invention.

[Explanation of symbols]

11a, 11b, 13a, 13b, 14a, 14b, 1
5a, 15b ... Auxiliary electrodes (internal electrodes) 27a, 27b, 28a, 28b ... Through holes 29 ... Laminated bodies 30, 31 ... External electrodes 40a-46b ... Through holes 53a, 53b ... Lead-out electrodes (internal electrodes) 57, 58 ... Through hole 59 ... Laminated body 61, 62 ... External electrode

Claims (2)

[Claims] 1. A laminate comprising at least an insulating member, an external electrode provided at an end of the laminate, an electrical electrode provided inside the laminate and electrically connected to the external electrode at an end face of the laminate. An electronic component, comprising: an internal electrode connected to the external electrode; and a through hole provided in the laminated body and electrically connected to the external electrode and the internal electrode. 2. The electronic component according to claim 1, wherein one end of the through hole provided at the end of the laminated body is exposed on the mounting surface of the laminated body.