JP3235467B2 - Electronic components - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to electronic components, mainly to surface-mounted electronic components.

[0002]

2. Description of the Related Art Piezoelectric components as shown in FIGS. 1 and 2 have been proposed as surface-mounted electronic components. This piezoelectric component includes an element 4 using piezoelectric vibration. Here, a piezoelectric element having electrodes 4a and 4b formed on the front and back surfaces is used, and the element 4 uses a length vibration mode. Electrodes 2 and 3 are formed in a pattern on the substrate 1 on which the piezoelectric element 4 is mounted, and a back side electrode 4 b of the piezoelectric element 4 is connected and fixed on one of the electrodes 2 by a conductive adhesive 5. The surface side electrode 4 a of the piezoelectric element 4 is connected to the other electrode 3 by a wire 6. A cap 7 covering the piezoelectric element 4 is bonded and sealed on the substrate 1 with an adhesive 8.

[0003]

In the case of the above-mentioned piezoelectric component, the front side electrode 4a of the piezoelectric element 4 and the electrode 3 of the substrate 1 are connected by a wire bonding method.
Since the heights of both connection points are different, it has been difficult to find appropriate conditions. Further, when the capillary is moved while being connected to one connection point, it is necessary to adjust the feed amount of the wire 6 to an appropriate length. For example, when the feeding amount of the wire 6 is short, as shown in FIG.
In the case where the amount of wire 6 to be sent out is long, the wire 6 falls down as shown in FIG. 4 and comes into contact with the piezoelectric element 4 to hinder the electrical property of the piezoelectric element 4. There was such a problem. For the above reasons, in the case of electronic components using wires, there is a problem that the quality is not stable and mass production is difficult. Further, since a wiring space for the wires 6 needs to be secured in the substrate 1 and the cap 7 in order to connect the front-side electrode 4a of the piezoelectric element 4 and the electrode 3 of the substrate 1, the electronic component becomes large. was there.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electronic component in which the electrical connection between a circuit element and an electrode pattern on a substrate is simple, the cost is low, the quality can be stabilized, and the size can be reduced. It is in.

[0005]

In order to achieve the above object, according to the first aspect of the present invention, a circuit element is mounted on an insulating substrate provided with an electrode pattern, and a cap covering the circuit element is adhered to the substrate. in sealed electronic component, at least the inner surface of the cap conductive portion is formed, electrostatic the calibration <br/> Tsu conductive portion or the electrically conductive portion of the flop and the counter circuit elements
One end of a conductive wire that is bent in a substantially U-shape at one of the poles
Is fixed, and the center of the wire is connected to the conductive part of the cap.
Or electrically connected to the other electrode of the circuit element,
Conductive part of the cap is connected with the electrode pattern on the substrate, the electrode and the substrate electrode pattern and the sum of the circuit element
It is characterized by being electrically conductive through the conductive portions of the ear and the cap. The invention according to claim 2 has at least a surface.
Also, a substrate on which the first and second electrodes are formed, and electrodes on the front and back surfaces
And a circuit element mounted on the substrate, and a circuit element
And a cap that is adhesively sealed on the substrate to cover the
And the back side electrode of the circuit element is in direct contact with the first electrode of the substrate.
In the continued electronic component, at least
A conductive portion is formed on the inner surface, and the conductive portion of the cap or
Is one of the surface-side electrodes of the circuit element facing this conductive part
In addition, both ends of the conductive wire that is bent in a substantially U shape are fixed.
The center of the wire is the conductive part of the cap or circuit.
It is electrically connected to the other electrode on the front side of the
The conductive portion of the tip is also connected to the second electrode on the substrate,
The surface side electrode of the circuit element and the second electrode of the substrate
And conductive through the conductive part of the cap
And

In order to connect an electrode of a circuit element to an electrode pattern of a substrate, the present invention employs a cap and a substantially U-shaped wire.
And are used. That is, by using the cap as a part of the wiring, the connection between the circuit element and the electrode pattern of the substrate can be simplified, the cost can be reduced, and the quality can be stabilized as compared with the connection by the conventional wire bonding method. be able to. In addition, since it is not necessary to secure a wiring space for wires for connecting the surface-side electrode of the circuit element and the electrode of the substrate inside the cap, the size of the cap can be reduced.

As the conductive portion of the cap, the cap itself may be formed of a metal material such as aluminum or copper, or the cap may be formed of an insulating material such as ceramics or resin, and a conductive film may be formed on at least the inner surface by sputtering.
It may be formed by a technique such as vapor deposition or printing.

When the circuit element is an element utilizing piezoelectric vibration with electrodes formed on the front and back surfaces, it is desirable to connect the vicinity of the node of the front surface side electrode of the element to the conductive portion of the cap. In this case, the conductive material for connecting the conductive portion of the cap and the surface side electrode of the piezoelectric element adheres to the vicinity of the node point, that is, to the non-vibration portion, so that the vibration of the piezoelectric element is not hindered,
It does not impair its electrical properties. The piezoelectric vibration mode includes a length vibration mode and a spreading vibration mode, and the like.
Each element has a node point at the center of the front and back surfaces of the piezoelectric ceramic substrate. Therefore, it is desirable to fix the center of the back surface of these piezoelectric elements to the substrate and connect the center of the front surface to the inner surface of the cap.

[0009]

5 and 6 show an example of an electronic component which is a premise of the present invention . This electronic component includes a substrate 10, a piezoelectric element 20, and a cap 30 as in the case of FIG.

The substrate 10 is a rectangular thin plate made of alumina ceramic, glass epoxy resin or the like, and two pattern electrodes 11 and 12 are formed on the upper surface of the substrate 10 by a known method such as sputtering, vapor deposition, and printing. ing. One of the electrodes 11 is connected to the external connection portion 11a.
Are formed in a strip shape along one short side of the substrate 10, and the internal connection portion 11 b extends in a direction perpendicular to the central portion of the substrate 10 from the external connection portion 11 a. The other electrode 12 is formed in a band along the other short side of the substrate 10.

On the upper surface of the substrate 10, the electrodes 11, 12
A frame-shaped insulating layer 13 such as an insulating resist pattern is formed thereon by a printing method. In the central space of the insulating layer 13, the internal connection portion 11b of one of the pattern electrodes 11 is exposed. This insulating layer 13 prevents short circuit between the pattern electrode 11 of the substrate 10 and the metal cap 30 and prevents the electrode 1
It has a function of alleviating irregularities on the surface of the substrate 10 due to the thicknesses of the caps 1 and 12 and preventing poor sealing of the cap 30.

The piezoelectric element 20 is, for example, a piezoelectric filter or a piezoelectric oscillator using a length vibration mode, and has electrodes 22 and 2 on the entire front and back surfaces of a rectangular piezoelectric ceramic substrate.
1 is formed. The central part of the back electrode 21 of the piezoelectric element 20 is exposed by the conductive adhesive 23 to the internal connection part 11 of the pattern electrode 11 exposed from the central space of the insulating layer 13.
b. After the conductive adhesive 23 is applied by a dispenser or printing, the element 20
The conductive adhesive 23 is cured by, for example, heating at 150 ° C. for 30 minutes. Thus, the substrate 10 and the element 20 are fixed, and the electrode 11 of the substrate 10 and the back electrode 21 of the element 20 are electrically connected. Note that a slight gap is provided between the element 20 and the insulating layer 13 so that both ends of the element 20 do not contact the insulating layer 13.

A metal cap 30 covering the element 20 is adhesively sealed on the substrate 10. Cap 30
The sealing adhesive 31 is applied in advance to the opening with a uniform thickness by transfer or the like. Further, a conductive adhesive 32 is applied by a dispenser on the surface electrode 22 of the element 20, particularly on the central part of the surface electrode 22 at the node point and its vicinity. The application amount of the conductive adhesive 32 is
In consideration of the clearance between the zero surface electrode 22 and the inner surface of the cap 30, it is necessary to adjust the adhesive 32 to such an amount that the adhesive 32 does not spread on the element 20 more than necessary. And cap 3
0 on the substrate 10, the opening of the cap 30 is in close contact with the insulating layer 13 of the substrate 10, and the cap 3
The inner surface of the conductive adhesive 32 is applied to the surface electrode 22 of the element 20.
Contact through. In this state, for example, at 150 ° C. for 30 minutes
If heated for a minute, the sealing adhesive 31 and the conductive adhesive 32
And hardens. As a result, the cap 30 is bonded and sealed to the substrate 10, and the surface electrode 22 of the element 20 and the cap 30 are sealed.
Electrical connection with the Since the sealing adhesive 31 of this embodiment is insulative and the insulating layer 13 is formed on the cap bonding portion of the substrate 10, the insulating property between the cap 30 and the electrode 11 of the substrate 10 is Is secured. Note that the sealing adhesive 31 may be a conductive adhesive.

After the sealing and sealing of the cap 30, the cap 30
Electrically conductive adhesive 33 on the outer surface of
Is applied with a dispenser and cured by heating under the same conditions as described above, so that the electrode 1 on the cap 30 and the substrate 10
2 are electrically connected. The conductive adhesive 33 is applied before the sealing adhesive 31 and the conductive adhesive 32 are cured by heating, and the heating and curing of the conductive adhesive 33 is performed by the sealing adhesive 31 and the conductive adhesive. 32 may be performed simultaneously with the heat curing.

As described above, the back electrode 21 of the piezoelectric element 20 is electrically connected to the pattern electrode 11 of the substrate 10 via the conductive adhesive 23, and the front electrode 22 is formed of the conductive adhesive 32 and the cap 30. Is electrically connected to the pattern electrode 12 of the substrate 10 via the conductive adhesive 33. Thus, a surface-mount type piezoelectric component is completed. As described above, since the connection between the piezoelectric element 20 and the pattern electrode 12 of the substrate 10 is performed by applying the conductive adhesive 32, multi-processing is possible, and the application of the conductive adhesive 32 is performed by wire bonding. As described above, since a large impact force is not applied to the element 20, the processing capability of the conductive connection can be increased without damaging the element 20. Also,
Since the wire drawing shape does not vary, the quality is stable and the wire drawing portion can be eliminated, so that there is an effect that a small electronic component can be obtained.

[0016]

[0017]

FIG . 7 shows a first embodiment of the present invention . The same parts as those in FIG. In this embodiment, both ends of the U-shaped conductive wire 37 are welded and fixed to the inner surface of the central portion of the metal cap 30, and the central portion of the wire 37 is pressed against the central portion of the surface electrode 22 of the piezoelectric element 20. It is made conductive. The wire 37 may be fixed to the inner surface of the cap 30 by a known means such as a wire bonder. In the above embodiment, the piezoelectric element 20
Heat treatment is required for electrical connection between
In addition, the influence of the heat treatment on the element 20 can be reduced. Ma
In addition, a clear run between the piezoelectric element 20 and the inner surface of the cap 30 is performed.
Can be absorbed by the deflection of the wire 37.
The tolerance of the dimensional accuracy of the cap 30 is wide. Note that the cap
In order to connect the pattern electrode 12 with the
The conductive tape 36 may be used instead of the adhesive.

[0019]

FIG . 8 shows a second embodiment of the present invention, and the same parts as those in FIG. In this embodiment, both ends of the U-shaped wire 39 are fixed to the upper surface of the central portion of the surface electrode 22 of the piezoelectric element 20 by a wire bonder. On the other hand, a conductive adhesive 40 is applied to the inner surface of the central portion of the metal cap 30 with a dispenser or the like so that the conductive adhesive 40 contacts only the wires 39 when the cap 30 is mounted on the substrate 10. After the cap 30 is mounted on the substrate 10, the conductive adhesive 40 is cured by heating, for example, by heating at 150 ° C. for 30 minutes. As a result, the cap 30 and the surface electrode 22 of the piezoelectric element 20 conduct through the wire 39 and the conductive adhesive 40.
The heat curing of the conductive adhesive 40 is performed by using the sealing adhesive 3.
Of course, it may be performed simultaneously with the heat curing of the conductive adhesive 33 and the conductive adhesive 33.

In this embodiment, since the conductive adhesive 40 does not adhere to the piezoelectric element 20, the electrical characteristics of the piezoelectric element 20 are not deteriorated. Also, when fixing the wire 39,
Since both ends are at the same height, they can be easily fixed by a wire bonder. Furthermore, by using the wire 39 and the conductive adhesive 40 together, the electrical connection becomes more reliable than when only the wire 39 is used. Since the heat of the conductive adhesive 40 during the heat treatment is not directly transmitted to the piezoelectric element 20, the effect of the heat of the piezoelectric element 20 can be reduced.

[0022]

[0023]

[0024]

[0025]

[0026]

The present invention is not limited to the above embodiment. For example, in the above embodiment, a metal cap is used as the cap.
Although a cap was used, the inner surface of the insulating cap
The conductive part that continues to the end
It may be formed by a known method. In the above embodiment, a single circuit element and a cap (conductive portion) are connected. However, a plurality of circuit elements are mounted on a substrate, and electrodes of the circuit elements are connected to each other by a wire or the like. The wire may be connected to the conductive portion of the cap or connected by a conductive adhesive or the like. Further, the electrode of the circuit element connected to the pattern electrode of the substrate via the conductive portion of the cap may be an input electrode, an output electrode or an earth electrode. In the case of a ground electrode, the use of a metal cap also performs the function of an electromagnetic shield. The number of electrode patterns formed on the substrate is not limited to two, and may be three or more. The circuit element of the present invention is not limited to a piezoelectric element such as a filter or an oscillator, but may be a capacitor element or a circuit module.

[0028]

As is apparent from the above description, according to the present invention, since the cap is used as a part of the wiring, the electrical connection between the electrode of the circuit element and the electrode pattern of the substrate can be simplified, and a large quantity can be obtained. An electronic component that is easy to produce and has stable quality can be provided. In addition, the power of the substrate
Direct connection between the pole pattern and the electrodes of the circuit element by wires
Unlike things, since the cap interior surface and the circuit element may be contact <br/> connection with a wire, it is unnecessary to wire wiring space for connecting the front electrode and the substrate electrode of the device, the electronic component There is an advantage that can be reduced in size. In addition, the circuit
Check for variations in clearance between the element and the inner surface of the cap.
Capable of dimensional accuracy of the cap because it can be absorbed by the deformation of the ear.
Wide range.

[Brief description of the drawings]

FIG. 1 is a perspective view of an example of a conventional electronic component.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a diagram showing another example of a defective wire AA in FIG. 1;
It is a line sectional view.

FIG. 5 is a perspective view of an example of an electronic component on which the present invention is based .

FIG. 6 is a sectional view taken along line BB of FIG. 5;

FIG. 7 is a sectional view of a first embodiment of the electronic component according to the present invention.

FIG. 8 is a sectional view of a second embodiment of the electronic component according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Substrate 11, 12 Pattern electrode 20 Circuit element (piezoelectric element) 21 Back electrode 22 Surface electrode 23 Conductive adhesive 30 Cap 37, 39 Wire 40 Conductive adhesive

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Makoto Irie 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto Co., Ltd. Inside Murata Manufacturing Co., Ltd. (72) Hiroyuki Kawakami 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto Co., Ltd. Inside Murata Manufacturing Co., Ltd. (72) Inventor Choichiro Fujii 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto Pref. Murata Manufacturing Co., Ltd. (56) References JP-A-8-8683 (JP, A) JP-A-8 -8677 (JP, A) JP-A-7-249956 (JP, A) JP-A-5-23617 (JP, U) JP-A-5-20422 (JP, U) JP-A 63-68215 (JP, U) US Patent 5,250,870 (US, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H03H 9/00-9/215 H01L 23/02-23/10

Claims (4)

(57) [Claims] An electronic component in which a circuit element is mounted on an insulating substrate provided with an electrode pattern and a cap covering the circuit element is adhesively sealed on the substrate, wherein a conductive portion is formed on at least an inner surface of the cap. conductive portion or the electrically conductive portion of the cap opposite to the circuit
A conductive wire curved in a substantially U-shape on one of the electrodes of the element
Both ends of the wire are fixed, and the center of the wire is a conductive part of a cap or a circuit element.
The conductive part of the cap is also connected to the electrode pattern on the substrate, and the electrode of the circuit element and the electrode pattern of the substrate are connected to each other by wires and wires.
Electronic component, characterized in that conducting through a conductive portion of the cap and. 2. A substrate having at least first and second electrodes formed on the front surface, electrodes formed on the front and back surfaces, a circuit element mounted on the substrate, and a circuit element mounted on the substrate so as to cover the circuit element. and a cap sealed, the electronic component backside electrode is directly connected to the first electrode of the substrate of the circuit element, at least the inner surface of the cap conductive portion is formed, the conductive portion of the cap Or a circuit facing this conductive part
One of the electrodes on the front surface of the element
Both ends of the wire are fixed, and the center of the wire is a conductive part of the cap or a circuit element.
Is connected to the front electrode to the other electrically conductive portion of the cap is also connected to a second electrode on the substrate, the second electrode and the wire surface side electrode and the substrate of the circuit element
An electronic component, wherein the electronic component is electrically connected to the electronic component via a conductive portion of the housing and the cap. 3. Both ends of said wire are conductive portions of a cap or
Is fixed to one of the electrodes of the circuit element, and the center of the wire is a conductive adhesive
Or, it is fixed to the other electrode of the circuit element
The electronic component according to claim 1 or 2, wherein Wherein said circuit element is an element using a piezoelectric vibrating, to one of 3 claims 1, characterized in that the node point near the electrodes of the device were connected to the conductive portion of the cap
Electronic components as described .