JP2000117973A - Piezoelectric vibrator unit and ink jet recording head - Google Patents

Abstract

(57) [Problem] Even if the width of a piezoelectric vibrator is reduced, conduction between an electrode on the piezoelectric vibrator side and a conductive pattern of a flexible tape is ensured, and a short circuit due to excess solder does not occur. To do. SOLUTION: A pattern width PW of a conductive pattern 26a is provided.
To the piezoelectric vibrator 11 (the width W of the segment external electrode 24).
A relatively long linear inclined portion 3 having a length L and a swing width D is provided at a connection portion 26a 'of the conductive pattern.
1 is included. By setting the swing width of the inclined portion larger than the width W of the segment external electrode, the effective conduction width is increased. Further, the non-overlapping region 33 not covered with the conductive pattern is formed on the segment external electrode by the inclined portion, and the surplus portion of the molten solder 34 escapes to the non-overlapping region.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording head (hereinafter, referred to as a recording head) for discharging ink droplets from nozzle openings by deformation of a piezoelectric vibrator.
The present invention relates to a piezoelectric vibrator unit used for the recording head, and more particularly to a technique for connecting a flexible tape to the piezoelectric vibrator.

[0002]

2. Description of the Related Art A piezoelectric vibrator used in an ink jet recording head is, for example, formed by alternately laminating a segment internal electrode as one pole and a common internal electrode as the other pole with a piezoelectric body interposed therebetween. It is formed by cutting the formed vibrator plate into a comb shape. On one side of this comb-shaped vibrator group, a segment external electrode electrically connected to the segment internal electrode is formed for each piezoelectric vibrator, and the segment external electrode is included so that a flexible tape for supplying a drive signal is provided. Are provided.

At this joint, each of the conductive patterns of the flexible tape is aligned so as to overlap with each of the piezoelectric vibrators.
The solder is melted in the matching state to electrically connect the conductor pattern of the flexible tape to the segment external electrodes provided on the piezoelectric vibrator.

The connection between the segment external electrode and each conductive pattern is usually performed by a soldering method using cream solder. This is because the width of the piezoelectric vibrator is, for example, 80 μm, and the width of the conductive pattern is, for example, 50 μm.
This is because such piezoelectric vibrators are arranged very densely.

[0005] By the way, it is required to reduce the power consumption of this type of recording head, and attempts have been made to reduce the width of the piezoelectric vibrator from this flow.

For example, if the width of the piezoelectric vibrator (corresponding to the width of the segment electrode) can be reduced from 80 μm to 50 μm, the displacement of the piezoelectric vibrator is reduced and the capacity of the piezoelectric vibrator is reduced by nearly 40%. be able to.

However, there are the following problems. That is, the above-mentioned alignment work usually involves matching the electrodes on one side and the electrodes on the other side of the segment external electrodes with the patterns on the one side and the other side in the conductive pattern of the flexible tape, respectively. It is done in. Moreover,
This work utilizes a technique in which the material of the flexible tape is a transparent polyimide resin, and is visually aligned through the top.

For this reason, when the width of the piezoelectric vibrator is reduced as described above, when the flexible tape and the piezoelectric vibrator are aligned with each other due to the component tolerance of the flexible tape, the cut position tolerance of the piezoelectric vibrator, and the like. In addition, there is a possibility that a positional error may occur in some of a large number of segment electrodes (piezoelectric vibrators), and if the positional error increases,
In some cases, a conductive pattern may be formed in a non-conducting state without riding on the segment external electrode.

In view of this, in order to correct the displacement, as shown in FIG. 13, the width of the piezoelectric vibrator 1 (corresponding to the width of the segment external electrode 2) X1 is changed to the conductive pattern 3 of the flexible tape. Was attempted to make the pattern width X2 sufficiently wide.

[0010]

However, as described above, the pattern width X2 of the conductive pattern 3 of the flexible tape is thus reduced.
Is simply made larger than the width X1 of the piezoelectric vibrator 1, the misalignment for the alignment is absorbed and the electric conduction is ensured, but on the other hand, the excess solder 4
Flows out from the side edge of the segment external electrode 2 to the side surface of the piezoelectric vibrator 1 (the side surface facing the adjacent vibrator), and short-circuits between the segment internal electrode 5 and the common internal electrode 6 of the piezoelectric vibrator 1. It turns out.

Therefore, an object of the present invention is to solve the above-mentioned problems and to ensure that the electrodes on the piezoelectric vibrator side and the conductive pattern of the flexible tape are electrically connected even when the width of the piezoelectric vibrator is reduced to, for example, 50 μm. Another object of the present invention is to provide a piezoelectric vibrator unit in which excess solder does not flow out to the side surface of the piezoelectric vibrator and short-circuit of the piezoelectric vibrator does not occur.

[0012]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and the present invention is directed to a segment internal electrode serving as one pole and a common internal electrode serving as the other pole. A piezoelectric vibrator formed by interposing a piezoelectric body between the piezoelectric vibrator and the piezoelectric vibrator is formed in a comb-like shape, and a connection portion with a flexible tape is provided on one side of the piezoelectric vibrator, and the connection portion is connected to a segment internal electrode. In a piezoelectric vibrator unit configured to dispose an external electrode and join a conductive pattern of a flexible tape and a segment external electrode by soldering, the conductive effective width of the conductive pattern at a connection portion of the flexible tape is determined by a piezoelectric vibrator. And a non-polymerized area that does not overlap with the conductive pattern is provided at the connection part of the piezoelectric vibrator. Characterized in that the solder of the surplus was formed so as to release the unpolymerized areas.

Here, "to form the piezoelectric vibrator in a comb-teeth shape" means that one piezoelectric vibrator plate is cut off in a comb-teeth shape by providing an uncut portion on the base end side. Of a single piezoelectric vibrator plate joined to a base (for example, a fixed plate) such that the edges of adjacent piezoelectric vibrators are cut off, etc., to form a comb-teeth shape including the base. Including both.

The "conducting effective width" means an effective width of a conductive pattern which can be conducted to a connection portion. For example, when the conductive pattern is meandered in the width direction of the piezoelectric vibrator at the connection portion, the interval between the meandering left and right ends corresponds to the conductive effective width of the conductive pattern.

According to a second aspect of the present invention, the pattern width of the conductive pattern is set to be equal to or less than the width of the segment external electrode of the piezoelectric vibrator, and the conductive pattern is bent in the width direction so that a part thereof protrudes from the piezoelectric vibrator. The piezoelectric vibrator unit according to claim 1, wherein the conductive effective width is made larger than the width of the piezoelectric vibrator, and a non-overlapping region is formed at a connection portion of the piezoelectric vibrator.

Here, the "pattern width of the conductive pattern" means the width of the stripe of the conductive pattern.

According to a third aspect of the present invention, the pattern width of the conductive pattern is set to be equal to or less than the width of the segment external electrode of the piezoelectric vibrator, and one edge of the conductive pattern is positioned with respect to one edge of the piezoelectric vibrator. Included in the conductive pattern is an inclined portion that crosses obliquely, so that the effective conduction width is wider than the width of the piezoelectric vibrator and a non-overlapping region is formed at the connection portion of the piezoelectric vibrator. A piezoelectric vibrator unit according to claim 1.

According to a fourth aspect of the present invention, the conductive effective width is made larger than the width of the piezoelectric vibrator by meandering the conductive pattern so as to have an amplitude larger than the width of the piezoelectric vibrator. The piezoelectric vibrator unit according to claim 1, wherein a non-overlapping region is formed at a connection portion of the element.

Here, "meandering" means to bend alternately in the left-right direction. Therefore, in addition to the S-shaped joints and undulations, there are also those that are bent in a crank shape and those that are bent in a saw-tooth shape.

According to a fifth aspect of the present invention, in the piezoelectric vibrator unit according to the fourth aspect, the conductive pattern is meandered so as to have a swell having an amplitude larger than the width of the piezoelectric vibrator. is there.

The piezoelectric vibrator unit according to claim 4, wherein the conductive pattern is meandering in a crank shape so as to have an amplitude larger than the width of the piezoelectric vibrator. It is.

According to a seventh aspect of the present invention, the conductive pattern includes a bulged portion wider than the width of the piezoelectric vibrator and a narrow portion narrower than the width of the piezoelectric vibrator. 2. The piezoelectric vibrator unit according to claim 1, wherein the width is wider than the width of the piezoelectric vibrator, and a non-overlapping region is formed at a connection portion of the piezoelectric vibrator.

According to another aspect of the present invention, the swollen portion and the narrow portion are alternately arranged with the center in the width direction of the swollen portion and the center in the width direction of the narrow portion arranged in the same row. The piezoelectric vibrator unit according to claim 7, wherein:

According to a ninth aspect of the present invention, a comb-shaped portion is formed by electrically connecting one end in the width direction between adjacent bulging portions by a narrow portion. It is a piezoelectric vibrator unit of the description.

According to a tenth aspect of the present invention, the length from the other end in the width direction of the narrow portion to the other end in the width direction of the bulging portion is set longer than the width of the piezoelectric vibrator. The connecting portion of the piezoelectric vibrator and the conductive pattern are configured to be connectable at the toothed portion of the swelling portion existing in the range from the other end edge of the swelling portion to the other end edge of the swelling portion. 9. The piezoelectric vibrator unit according to item 9.

[0026] According to an eleventh aspect of the present invention, the piezoelectric vibrator is formed by alternately stacking segment internal electrodes and common internal electrodes with a piezoelectric body interposed therebetween. Item 11. The piezoelectric vibrator unit according to any one of Items 10.

According to a twelfth aspect of the present invention, there is provided a pressure chamber which is partially defined by an elastic sheet and is in communication with a nozzle opening, and which comes into contact with the elastic sheet.
1. The pressure of the ink filled in the pressure chamber is changed by transmitting the deformation of the piezoelectric vibrator constituting the piezoelectric vibrator unit to the elastic sheet. An ink jet recording head characterized in that an ink droplet is ejected from a nozzle opening by utilizing a change in the ink jet recording head.

[0028]

Embodiments of the present invention will be described below with reference to the drawings. Here, FIG. 1A is a perspective view of the piezoelectric vibrator unit 10, and FIG. 2 is a diagram illustrating an overall configuration of the piezoelectric vibrator unit 10.

The illustrated piezoelectric vibrator unit 10 is generally constituted by a piezoelectric vibrator 11, a fixing plate 12, and a flexible tape 13.

The piezoelectric vibrators 11 are formed by dividing the vibrator plate into comb teeth so that each piezoelectric vibrator 11 has a width of about 50 μm. This piezoelectric vibrator 11
Are arranged in rows between the dummy vibrators 14 located at both ends to form a vibrator group 15.

Each piezoelectric vibrator 11 includes a segment internal electrode 21 serving as one pole and a common internal electrode 22 serving as the other pole, as shown in an enlarged cross section in FIG. It is configured so that it is sandwiched and stacked alternately. Also,
A segment external electrode 24 is provided on one surface (upper surface in an enlarged view) of the piezoelectric vibrator 11, and a common external electrode 25 is provided on the other surface (same lower surface). The segment external electrode 24 is an electrode electrically connected to the segment internal electrode 21, and the common external electrode 25 is an electrode electrically connected to the common internal electrode 22. These segment external electrodes 2
4 and the common external electrode 25 are electrodes provided to supply a drive signal from the conductive pattern 26 of the flexible tape 13 to the segment internal electrode 21 and the common internal electrode 22.

The piezoelectric vibrator 11 of the present embodiment is
It is constituted by a so-called longitudinal vibration mode piezoelectric vibrator 11 in which the lamination direction of the electrodes is orthogonal to the expansion and contraction direction of the piezoelectric vibrator 11. When the piezoelectric vibrator 11 in such a longitudinal vibration mode is used for driving an ink jet recording head, the contact area between the piezoelectric vibrator 11 and the diaphragm can be extremely reduced, so that high resolution and high-speed driving can be achieved. Become.

The dummy vibrator 14 is a vibrator that does not participate in the ejection of ink droplets, and is provided wider than the piezoelectric vibrator 11. A common external electrode 25 is provided on the surface of the dummy vibrator 14. The common external electrode 25 is provided in series with the common external electrode 25 provided on the other surface of the piezoelectric vibrator 11 and is electrically connected to each other.

The fixing plate 12 is a member for fixing the piezoelectric vibrator unit 10 to the case of the recording head, and is made of, for example, a plate-like stainless material. The fixed plate 12 is used as a common external electrode 2 in the piezoelectric vibrator 11.
5, the piezoelectric vibrator 11 is joined so as to leave a free end portion. Note that the fixed plate 12 is joined to the vibrator plate before the splitting, and the vibrator plate is cut into a comb-like shape while being joined to the fixed plate 12.

As shown in FIGS. 2B and 2C, the flexible tape 13 is made of a flexible film such as a polyimide resin as a base material 13a, and a copper foil or the like is etched on the surface thereof to form a conductive pattern 26. Is formed.
As shown in FIG. 2A, the conductive pattern 26 includes a conductive pattern 26a for connecting a segment electrode and a conductive pattern 26b for connecting a common electrode.

Conductive pattern 26 for connecting segment electrodes
a is formed at a pitch substantially corresponding to the pitch of the segment external electrodes 24 of the piezoelectric vibrator 11, and each pattern width is equal to the width of each segment external electrode 2 which is the width of the piezoelectric vibrator 11.
4 is formed to have a width that is equal to or slightly smaller than the width of 4. In this embodiment, the width of the segment external electrode 24 is set to 5
It has a width of 0 μm.

The tip of the conductive pattern 26a is formed as a connection portion 26a 'having a solder plating layer 27. Connection part 26a 'of this conductive pattern 26a
Is a connection portion 11a on the piezoelectric vibrator 11 side, that is, a portion connected to the base end portion on the surface on which the segment external electrode 24 is formed. The connection portion 26a 'of the conductive pattern 26a is connected to the connection portion on the piezoelectric vibrator 11 side. In the state polymerized to 11a,
By reflowing the solder plating layer 27, the conductive pattern 26a and the segment external electrode 24 are joined in a conductive state.

The conductive pattern 26a closer to the base end than the connection portion 26a 'is formed of a resist layer 13 for preventing short circuit.
b.

Then, the connection portion 2 of the conductive pattern 26a
The conductive effective width in 6 a ′ is set wider than the width of the piezoelectric vibrator 11, and the conductive pattern is formed such that a non-polymerized region that does not overlap with the conductive pattern 26 a is formed at the connection portion of the piezoelectric vibrator 11. The direction of 26a and the dimension of the pattern width are selected. This non-polymerized area is the conductive pattern 2
This is an area for releasing excess solder melted at the time of joining 6a. The specific configuration of this part will be described later in detail.

On the other hand, the conductive pattern 26 for connecting the common electrode
“b” is formed to have substantially the same width as the width of the dummy vibrator 14, and a solder plating layer is provided at a tip portion thereof. Then, the leading end portion of the conductive pattern 26b for connecting the common electrode is superimposed on the common external electrode 25 of the dummy vibrator 14, and the solder plating layer is reflowed in this superposed state, so that the common external electrode 25 and the conductive pattern 26b Are connected in a conductive state.

In the piezoelectric vibrator unit 10 having such a configuration, the driving signal for each piezoelectric vibrator 11 is supplied from the conductive pattern 26a for connecting the segment electrodes of the flexible tape 13, and the conductive signal for connecting the common electrode is supplied. The pattern 26b is set to a ground (GND) potential. Therefore, in each of the piezoelectric vibrators 11, a potential difference is generated between the segment internal electrode 21 and the common internal electrode 22 by the supply of the drive signal, and the piezoelectric vibrators 11
Expands and contracts in the longitudinal direction of the vibrator. Then, ink droplets are ejected by utilizing the expansion and contraction of the vibrator in the longitudinal direction.

That is, in a state where the recording head is assembled,
As shown in FIG. 1B, the piezoelectric vibrator 11 is
The distal end 11b is brought into contact with the elastic sheet 29 that defines a part of 8A. The elastic sheet 29 is deformed as the piezoelectric vibrator 11 expands and contracts in the vibrator longitudinal direction, and the pressure chamber 2
The pressure of the ink filled in 8A is changed. Then, by the change in the ink pressure, an ink droplet is ejected from the nozzle opening 30a communicating with the pressure chamber 28A.

The pressure chamber 28A includes a spacer member 28, an elastic sheet 29 and a nozzle plate 30. That is, the pressure chamber 28A is
A nozzle plate 30 having a nozzle opening 30a is arranged on the front surface of the spacer member 28, and an island portion 29a with which the tip 11b of the piezoelectric vibrator 11 contacts is provided on the back surface of the spacer member 28. A pressure chamber 28A defined by the elastic sheet 29 and the nozzle plate 30 is formed by disposing the elastic sheet 29 and integrating these members by bonding or the like.

Next, the piezoelectric vibrator 11 in the present embodiment
The specific configuration of the connection portion 11a of the first embodiment and the connection portion 26a 'of the conductive pattern 26a for connecting the segment electrodes (hereinafter simply referred to as the conductive pattern 26a) will be described in detail.

FIG. 3 shows the conductive pattern 26 a of the flexible tape 13 on the segment external electrode 24 of the piezoelectric vibrator 11.
FIG. 4 is a partially enlarged view of FIG. 4, and FIG. 5 is a view illustrating a joining portion between the segment external electrode 24 and the conductive pattern 26a.

In the present embodiment, the conductive pattern 26a is bent in the width direction so that a part of the conductive pattern 26a (connection portion 26a ') protrudes from the piezoelectric vibrator 11 in a connected portion. Specifically, the conductive pattern 26a
Is equal to or slightly smaller than the width W of the piezoelectric vibrator 11 (that is, the width W of the segment external electrode 24), and the connection portion 26a 'of the conductive pattern 26a is formed.
And a relatively long linear inclined portion 31 having a length L and a swing width D. Due to this inclined portion 31, the edge of one side of the conductive pattern 26a is
Is obliquely intersected with the edge on one side.

By providing such an inclined portion 31, the swing width D of the conductive pattern 26a (that is, the connection portion 26a ') is larger than the width W of the segment external electrode 24. Therefore, when viewed in the longitudinal direction of the segment external electrode 24, a portion that protrudes from the edge of the segment external electrode 24 in the width direction is formed in the conductive pattern 26a. In other words, the arrangement area of the conductive pattern 26a as viewed in the longitudinal direction of the segment external electrode 24 is expanded in the width direction of the segment external electrode 24. The protruding portion can increase the width in which the conductive pattern 26a and the segment external electrode 24 can conduct, that is, the effective conduction width (corresponding to the swing width D).

Since the effective conduction width is expanded, in this configuration, the conductive patterns 26a, 26a at both ends are formed.
a and the segment external electrodes 24, 24 at both ends are merely overlapped, and all the conductive patterns 26
and the segment external electrodes 24 can be reliably conducted. In other words, even if the accuracy of matching between the conductive pattern 26a and the segment external electrode 24 is roughened (the dimensional tolerance is roughened), the conductive pattern 26a and the segment external electrode 24 can be reliably conducted.

Further, the opaque flexible tape 13
2, visible windows 32, 32 are provided at both ends of the flexible tape 13 as shown by the dashed lines in FIG. 2, and the conductive patterns 26 a, 26 a at both ends are provided through these visible windows 32, 32. Segment external electrodes 24, 24
, And all of the segment conductive patterns 26a.
Can be reliably conducted.

Further, as shown in FIGS. 4 and 5, a portion protruding from one side in the width direction of the segment external electrode 24 is formed in the conductive pattern 26a. Conductive pattern 26 on the side
A non-polymerized area 33 not covered with a is formed.

The non-polymerized area 33 is formed by the conductive pattern 26
a (the connecting portion 26a ') functions as a region where the excess of the melted solder 34 escapes. Then, as a result of the surplus amount of the solder 34 melted on the non-polymerized region 33 escaping, the solder 3 escaping on the non-polymerized region 33 by the action of surface tension.
The surplus of 4 remains on the non-polymerized region 33, that is, on the segment external electrode 24.

Accordingly, it is possible to reliably prevent an accident that the segment internal electrode 21 and the common internal electrode 22 of the piezoelectric vibrator 11 are short-circuited by the solder flowing out between the conductive pattern 26a and the segment external electrode 24. Thus, the production yield can be improved.

It is to be noted that the above-mentioned inclined portion 31 may be provided such that the edges on both sides of the conductive pattern 26a obliquely intersect with the edges on one side of the segment external electrode 24 by further increasing the inclination.

In the above-described embodiment, the inclined portion 3 is bent so that a part thereof protrudes from the piezoelectric vibrator 11.
1 is included in the connection portion 26a 'of the conductive pattern 26a, but the present invention is not limited to this configuration.

For example, the connection portion 2 of the conductive pattern 26a
6a 'is meandered so as to have an amplitude larger than the width W of the piezoelectric vibrator 11, and the meandering makes the effective conduction width larger than the width W of the piezoelectric vibrator 11;
Can also be formed.

Hereinafter, an embodiment in which the conductive pattern 26a is meandered will be described.

FIG. 6 is a view for explaining a state in which the conductive pattern 26a of the flexible tape 13 is overlaid on the segment external electrode 24 in this embodiment.
Is a partially enlarged view of FIG.

As shown in these figures, in the present embodiment, the pattern width PW of the conductive pattern 26a is set to be equal to or smaller than the width of the segment external electrode 24 of the piezoelectric vibrator 11, and the conductor for connecting the segment is formed. Pattern 26a
, That is, the tip side portion 35 of the connection portion 26a '
The segment external electrode 24 is meandering in a substantially S-shape so as to have a swell having a swing width D larger than the width W of the segment external electrode 24.

More specifically, the conductive pattern 2 is formed from one side edge and the other side edge of the segment external electrode 24 of the piezoelectric vibrator 11.
The leading end portion 35 of the conductive pattern 26a is meandering in the width direction so that 6a partially protrudes alternately and in parallel with the edge of the segment external electrode 24.

In this embodiment, as in the first embodiment described above, the swing width (effective conduction width) D, which is the distance between the meandering left and right ends of the conductive pattern 26a, is equal to the width of the segment external electrode 24. Wider than W. As a result, the width that can be used for conduction is widened, so that the conduction between the conductive pattern 26a and the segment external electrodes 24 can be ensured even if the accuracy of the matching is roughened.

When the conductive pattern 26a and the segment external electrode 24 are joined within the swing width D of the conductive pattern 26a, a region (overlapping region) 36 covered with the conductive pattern 26a is formed on the segment external electrode 24. Area (non-polymerized area) 33 not covered with conductive pattern 26a
Is formed. For this reason, the surplus amount of the solder 34 that has melted when the conductive pattern 26a is joined escapes to the non-overlapping region 33 that is not covered with the conductive pattern 26a. Then, the escaped surplus solder 34 remains on the non-polymerized region 33 (that is, on the segment external electrode 24) due to surface tension. Therefore, it is possible to prevent the solder 34 from flowing out to the side surface of the piezoelectric vibrator 11 (the side surface facing the adjacent vibrator), and it is possible to reliably prevent a short circuit between the segment internal electrode 21 and the common internal electrode 22.

The meandering of the conductive pattern 26a is not limited to the S-shaped undulation, and may be, for example, a crank-shaped meandering or a serrated meandering. Hereinafter, an embodiment that is meandering in a crank shape will be described.

FIG. 8 is a view for explaining an embodiment in which the crankshaft is meandered. As shown in the figure, the crank portion 37 of the illustrated conductive pattern 26a (connection portion 26a ')
Are bent so that the ends in the width direction alternately protrude from one side edge and the other side edge of the width W of the segment external electrode 24 and substantially parallel to the edge of the segment external electrode 24.

More specifically, the crank portion 37 has a crossing portion 37 a crossing the segment external electrode 24 in the width direction.
And parallel portions 37b along the longitudinal direction. The parallel portions 37b are alternately arranged on one side and the other side in the width direction of the segment external electrode 24, and the parallel portions 37b
Are connected by crossing portions 37a.

Also in this embodiment, the swing width (effective conduction width) D is larger than the width W of the segment external electrode 24, similarly to the above-described embodiment.
4 and the conductive pattern 26a can be reliably conducted. Also,
Since the overlap region 36 covered with the conductive pattern 26a and the non-overlap region 33 not covered with the conductive pattern 26a are formed in the region of the width W of the segment external electrode 24, the surplus portion in the non-overlap region 33 is formed. Solder 34 escaped, Solder 3
4 can be prevented from flowing to the side face of the vibrator, and a short circuit between the segment internal electrode 21 and the common internal electrode 22 can be reliably prevented.

In each of the above embodiments, the conductive effective width is increased and the non-overlapping region 3 is formed by bending or winding the conductive pattern 26a in an oblique direction.
3, the present invention is not limited to these configurations.

For example, a protruding portion wider than the width of the segment external electrode 24 (ie, the width of the piezoelectric vibrator 11) and a narrow portion narrower than the width of the segment external electrode 24 are connected to the connecting portion of the conductive pattern 26a. 26a ', the effective conduction width may be increased, and the non-overlapping region 33 may be provided.

Hereinafter, an embodiment in which a bulging portion and a narrow portion are provided will be described.

First, a description will be given of an embodiment in which the swollen portions and the narrow portions are alternately arranged in a state where the center in the width direction of the swollen portion and the center in the width direction of the narrow portion are arranged on the same row.
Here, FIG. 9 is a view for explaining a state in which the conductive pattern 26a of the flexible tape 13 is overlaid on the segment external electrodes 24, and FIG. 10 is a partially enlarged view thereof.

As shown in these figures, the conductive pattern 26a of this embodiment has a bulging portion 40 formed at a tip end portion of a connecting portion 26a 'and having a width DW larger than the width W of the piezoelectric vibrator 11. A narrow portion 41 formed to have a width T smaller than the width of the piezoelectric vibrator 11 is included.

The center DW /
2 and the center T / 2 in the width direction of the narrow portion 41 are arranged in the same row, more specifically, in a state where the centers in the width direction are substantially aligned with each other, the bulging portion 40 and the narrow portion 41 are Are alternately arranged along the longitudinal direction of the segment external electrodes 24. In other words, the bulging portions 40 and the narrow portions 41 are alternately arranged along the longitudinal direction of the conductive pattern 26a so as to have a line-symmetric relationship with respect to the center line CL passing through the center in the width direction. I have.

In this embodiment, the width DW of the bulging portion 40 is
Is the effective conduction width, and since the effective conduction width is set to be wider than the width W of the segment external electrode 24 (piezoelectric vibrator 11), the segment external electrode 24 and the conductive pattern 26a
Can be reliably conducted.

Since the width T of the narrow portion 41 is smaller than the width W of the segment external electrode 24, the non-overlapping region 33 not covered with the conductive pattern 26a is formed on the side of the narrow portion 41. Is formed. For this reason, the surplus solder 34 escapes to the non-overlapping area 33, and the outflow of the solder 34 to the side surface of the vibrator can be prevented, and the short circuit between the segment internal electrode 21 and the common internal electrode 22 can be reliably prevented.

Next, a description will be given of an embodiment in which a bulge portion and a narrow portion constitute a comb-like portion.

As shown in FIG. 11, in this embodiment,
One end in the width direction between the adjacent bulging portions 40, 40, for example, the left half portions of the bulging portions 40, 40 are connected to the narrow width portion 41.
The bulging portions 40 and the narrow portions 41 are alternately arranged along the longitudinal direction of the conductive pattern 26a to form a comb-like portion.

Also in this embodiment, the width DW of the bulging portion 40 is
Is the effective conduction width, and conduction between the segment external electrode 24 and the conductive pattern 26a can be reliably performed.

Since the width T of the narrow portion 41 is smaller than the width W of the segment external electrode 24, the non-overlapping region 33 not covered with the conductive pattern 26a is formed on the side of the narrow portion 41. Is formed, the solder 34 can escape to the non-overlapping region 33, and the outflow of the solder 34 to the side face of the vibrator can be prevented.

Further, since the narrow portion 41 is provided so as to join the left half portions of the bulging portions 40, 40, the area per one of the non-polymerized regions 33 to be formed can be increased. The solder 34 can surely escape to the non-overlapping area 33.

In the embodiment shown in FIG. 12, one end in the width direction of the adjacent bulging portions 40, 40 is connected to the narrow portion 41.
In this configuration, the distance from the other end in the width direction of the narrow portion 41 to the other end in the width direction of the bulging portion 40 is longer than the width of the piezoelectric vibrator. It is set.

In this embodiment, as shown in the figure, the left end portions of adjacent bulging portions 40, 40 are joined to each other by a narrow width portion 41, and the bulging portion 40 and the narrow width portion 41 are joined together.
Are alternately arranged along the longitudinal direction of the conductive pattern 26a to form a comb-like portion. In this comb-like portion, the bulging portion 40 extends from the right edge 41 a of the narrow portion 41.
Is set to be longer than the width W of the segment external electrode 24, that is, the length S to the right edge 40a of the swelling portion 40, that is, the length of the tooth portion 40b of the bulging portion 40.

Therefore, in this embodiment, the bulging portion 40
The joint 40 between the segment external electrode 24 and the conductive pattern 26a can be formed by the toothed portion 40b. That is, the segment external electrode 24 and the conductive pattern 26a can be joined without joining the narrow portion 41 to the segment external electrode 24.

When the bonding is performed at the toothed portion 40b, the segment external electrode 24 and the conductive pattern 26a are laid in a state where the toothed portion 40b crosses over the segment external electrode 24.
Can be joined, and the area of the non-polymerized region 33 can be further increased. Therefore, the outflow of the solder 34 to the side surface of the vibrator can be more reliably prevented.

In this configuration, since the non-overlapping region 33 can be reliably formed, when the width W of the segment external electrode 24 (piezoelectric vibrator 11) is further reduced (for example, the width W
Is formed to about 30 μm).

In the above description, the lamination direction of the segment internal electrode 21 and the common internal electrode 22 is
Although the piezoelectric vibrator 11 in the vertical vibration mode perpendicular to the expansion and contraction direction of the piezoelectric vibrator 1 is illustrated, the present invention relates to a piezoelectric vibrator in a flexural vibration mode in which the lamination direction of the segment internal electrode and the common internal electrode is parallel to the expansion and contraction direction of the piezoelectric vibrator. It can also be used for a vibrator.

[0085]

As described above, the present invention has the following effects.

That is, since the effective conduction width of the conductive pattern is provided wider than the width of the piezoelectric vibrator, a portion where the segment external electrode of the piezoelectric vibrator and the conductive pattern can be overlapped when viewed in the longitudinal direction of the piezoelectric vibrator. Becomes wider. Thus, even if the accuracy of matching between the conductive pattern and the segment external electrode is somewhat roughened, both can be reliably conducted.

Thus, by simply aligning the conductive patterns at both ends and the segment external electrodes, all the conductive patterns existing therebetween and the segment external electrodes can be electrically connected, and the segment external electrodes of the piezoelectric vibrator can be electrically connected. Joining work with the conductive pattern of the flexible tape becomes very easy. Furthermore, since the joining operation does not require skill, the production yield can be improved.

Since the dimensional tolerance can be made rougher than before, the production yield can be improved also in this respect.

Further, since a non-polymerized region which does not overlap with the conductive pattern is provided at the connection portion of the piezoelectric vibrator, an excess portion of the melted solder is removed when joining the conductive pattern and the segment external electrode. Flee inside. The surplus solder that escapes into the non-polymerized region is subjected to surface tension, so that the solder remains on the segment external electrodes. Therefore, it is possible to prevent an accident that the segment internal electrode and the common internal electrode of the piezoelectric vibrator are short-circuited by the leaked solder, thereby improving the production yield.

[Brief description of the drawings]

FIG. 1A is a perspective view of a piezoelectric vibrator unit, and FIG.
FIG. 3 is an enlarged view of the vicinity of a pressure chamber in the recording head.

FIG. 2A is a plan view of a piezoelectric vibrator unit, and FIG.
(C) is a partially enlarged view of the flexible tape.

FIG. 3 is a diagram illustrating an electrical connection portion between a piezoelectric vibrator and a flexible tape in an embodiment in which a conductive pattern is bent in a width direction.

FIG. 4 is a partially enlarged view of FIG. 3;

FIG. 5A is a partially enlarged cross-sectional view illustrating an electrical connection portion between a piezoelectric vibrator and a flexible tape, and FIG. 5B is a partially enlarged view illustrating a non-polymerized region.

FIG. 6 is a diagram illustrating an electrical connection portion between a piezoelectric vibrator and a flexible tape in an embodiment in which a conductive pattern meanders in an S shape.

FIG. 7 is a partially enlarged view of FIG. 6;

FIG. 8 is a partially enlarged view of the embodiment in which the conductive pattern is meandering in a crank shape.

FIG. 9 is a diagram illustrating an electrical connection portion between a piezoelectric vibrator and a flexible tape in an embodiment in which a bulging portion and a narrow portion are provided.

FIG. 10 is a partially enlarged view of FIG. 9;

FIG. 11 is a partially enlarged view of an embodiment in which a comb-shaped portion is formed by a bulging portion and a narrow portion.

FIG. 12 is a partially enlarged view of another embodiment in which comb-shaped portions are formed.

13A and 13B are diagrams illustrating the problem of the present invention, in which FIG. 13A illustrates a state in which solder has flowed out, and FIG. 13B illustrates a relationship between the width of the piezoelectric vibrator and the width of the conductive pattern. It is.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Piezoelectric vibrator unit 11 Piezoelectric vibrator 11a Connection part 12 Fixing plate 13 Flexible tape 14 Dummy vibrator 15 Vibrator group 21 Segment internal electrode 22 Common internal electrode 23 Piezoelectric body 24 Segment external electrode 25 Common external electrode 26 Conductive pattern 26a Segment Conductive pattern for electrode connection 26a 'Connection part 27 Solder plating layer 28 Spacer member 28A Pressure chamber 29 Elastic sheet 30 Nozzle plate 30a Nozzle opening 31 Inclined part 32 Viewing window part 33 Non-polymerized area 34 Excess solder 35 S-shaped in conductive pattern Meandering portion 36 overlapping region 37 crank portion 40 bulging portion 41 narrow width portion W width of piezoelectric vibrator (segment external electrode) D, DW Effective conduction width (fluctuation width of conductive pattern, width of bulging portion)

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Toshihisa Shinbo 3-3-5 Yamato, Suwa-shi, Nagano F-term in Seiko Epson Corporation (reference) 2C057 AF93 AG12 AG44 AG48 AG82 AG90 AG92 AG93 AG94 AP02 AP16 AP24 AP77 BA14

Claims (12)

[Claims] 1. A piezoelectric vibrator having a piezoelectric body sandwiched between a segment internal electrode serving as one pole and a common internal electrode serving as the other pole is formed in a comb-like shape, and is provided on one side surface of the piezoelectric vibrator. The piezoelectric tape is provided with a connection portion with a flexible tape, a segment external electrode electrically connected to the segment internal electrode is arranged at the connection portion, and the conductive pattern of the flexible tape and the segment external electrode are joined by soldering. In the vibrator unit, the conductive effective width of the conductive pattern at the connection portion of the flexible tape is provided to be wider than the width of the piezoelectric vibrator, and a non-polymerized region that does not overlap with the conductive pattern is provided at the connection portion of the piezoelectric vibrator. A piezoelectric vibrator unit characterized in that a surplus amount of solder melted at the time of pattern joining is released to a non-polymerized area. 2. The conductive effective width is set to be smaller than the width of the segment external electrode of the piezoelectric vibrator by bending the conductive pattern in the width direction so that a part thereof protrudes from the piezoelectric vibrator. 2. The piezoelectric vibrator unit according to claim 1, wherein a width of the vibrator is larger than a width of the vibrator and a non-overlapping region is formed at a connecting portion of the piezoelectric vibrator. 3. The pattern width of the conductive pattern is set to be equal to or less than the width of the segment external electrode of the piezoelectric vibrator, and an inclined portion where one edge of the conductive pattern obliquely intersects one edge of the piezoelectric vibrator is provided. 2. The piezoelectric device according to claim 1, wherein the effective width of conduction is made larger than the width of the piezoelectric vibrator and a non-overlapping region is formed at a connection portion of the piezoelectric vibrator by being included in the conductive pattern. Transducer unit. 4. The conductive pattern is meandered so as to have an amplitude larger than the width of the piezoelectric vibrator, so that the effective conduction width is larger than the width of the piezoelectric vibrator, and the connection portion of the piezoelectric vibrator is non-polymerized. The piezoelectric vibrator unit according to claim 1, wherein the region is formed. 5. The piezoelectric vibrator unit according to claim 4, wherein the conductive pattern is meandered so as to have undulation having an amplitude larger than the width of the piezoelectric vibrator. 6. The piezoelectric vibrator unit according to claim 4, wherein the conductive pattern is meandering in a crank shape so as to have an amplitude larger than the width of the piezoelectric vibrator. 7. A conductive effective width is reduced by including a bulged portion wider than the width of the piezoelectric vibrator and a narrow portion narrower than the width of the piezoelectric vibrator in the conductive pattern. 2. The piezoelectric vibrator unit according to claim 1, wherein the non-overlapping region is formed at a connection portion of the piezoelectric vibrator. 8. The swelling portion and the narrow portion are alternately arranged in a state where the center in the width direction of the swelling portion and the center in the width direction of the narrow portion are arranged on the same row. 4. The piezoelectric vibrator unit according to item 1. 9. The piezoelectric vibrator unit according to claim 7, wherein one end in the width direction between adjacent bulging portions is electrically connected to each other at a narrow width portion to form a comb-like portion. 10. The length from the other end in the width direction of the narrow portion to the other end in the width direction of the bulging portion is set to be longer than the width of the piezoelectric vibrator, and bulging from the other end edge of the narrow portion. The piezoelectric vibrator according to claim 9, wherein the connection portion of the piezoelectric vibrator and the conductive pattern are configured to be connectable at the tooth portion of the bulging portion existing in a range up to the other end edge of the portion. unit. 11. The piezoelectric vibrator according to claim 1, wherein the segmented internal electrodes and the common internal electrodes are alternately laminated with a piezoelectric body interposed therebetween. Piezoelectric vibrator unit. 12. A pressure chamber partly partitioned by an elastic sheet and communicating with a nozzle opening, and the piezoelectric vibrator unit according to claim 1 contacting the elastic sheet. By transmitting the deformation of the piezoelectric vibrator constituting the piezoelectric vibrator unit to the elastic sheet, the pressure of the ink filled in the pressure chamber is changed, and the ink droplet is ejected from the nozzle opening by utilizing the change of the ink pressure. An ink jet recording head, characterized in that the ink jet recording head is configured to be driven.