JP3456516B2 - Method for manufacturing piezoelectric vibrator unit for inkjet recording head - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure generating chamber having one surface sealed with a vibrating plate, and the vibrating plate being pressed by a piezoelectric vibrator in a longitudinal vibration mode. The present invention relates to a method for manufacturing a piezoelectric vibrator unit suitable for an ink jet recording head that generates ink droplets from nozzle openings by expanding and contracting a generation chamber. 2. Description of the Related Art For example, when a piezoelectric vibrator in a longitudinal vibration mode as disclosed in Japanese Patent Application Laid-Open No. 5-104715 is used for driving an ink jet recording head, the piezoelectric vibrator and the vibrating plate may be in contact with each other. Since the contact area can be made extremely small, a resolution of 180 DPI or more per unit can be realized. As shown in FIG. 8, a piezoelectric vibrator A in a longitudinal vibration mode has an internal electrode B serving as one pole and an internal electrode C serving as the other pole laminated in a sandwich manner via a piezoelectric material D. One internal electrode B is exposed on the front end side, and the other internal electrode C is exposed on the rear end side, and is configured as having a piezoelectric constant d31 connected to the segment electrode E and the common electrode F at each end face, It is arranged and fixed at a fixed pitch on the fixed substrate G, and is configured to supply a signal from an external drive circuit by connecting the conductive pattern of the flexible cable H to the segment electrode E and the common electrode F. . [0004] Since the driving current of all the piezoelectric vibrators A flows through the common electrode F formed on the rear end side, the resistance of the common electrode F is reduced as much as possible. The conductive layers F1 to F3 are provided on the upper surface, the rear end surface, and the back surface of the piezoelectric vibrator A.
F3 is formed, and is divided into comb teeth so as to leave a part of the rear end side to secure a conductive path. In addition,
Reference numeral J in the figure denotes a flow path unit that receives ink pressurization by the piezoelectric vibrator A and discharges ink droplets. For this reason,
Electrode layers for external connection are required on the four surfaces of the front end surface, the rear end surface, and the front and back surfaces of the piezoelectric vibrator A, and these external electrode layers are intended to ensure corrosion resistance to ink and ease of soldering. Gold is used in. For this reason, if an attempt is made to form a thick electrode layer to reduce the resistance of the electrode layer to enable high-speed driving, there is a problem in that the formation of the electrode is costly. The present invention was made in view of such problems, a manufacturing method of piezoelectric vibrator unit for an ink jet recording head capable of reducing the charge for high valence electrode material and its object the it is to <br/> proposed. [0005] In order to solve such a problem, in the present invention, an internal electrode serving as one of the poles is provided.
The other internal electrode and the piezoelectric material are alternately stacked
And only one end of each internal electrode is exposed at the front and rear ends.
The piezoelectric vibrating plates laminated so as to be
Lay them together and share them with the front and back segment electrodes.
The mask material is fixed to the boundary area between the
A step of depositing a pole forming material;
The diaphragm is separated, and the mask material is removed.
Adhesive area to at least a fixed substrate with conductive surface
And fixing at least from the free end side tip
Forming a slit up to the rear end of the segment electrode;
Was prepared. A thickened common electrode is provided on the rear end face of the piezoelectric vibrator.
Since it is formed, the surface of the fixed substrate facing the common electrode
Connected in parallel. Therefore, the two sides of the piezoelectric vibrator
Even if a conductive layer serving as a common electrode is formed only
Can be reduced to minutes . 1 and 2 show one embodiment of an ink jet recording head according to the present invention. In a flow passage unit 1, nozzle openings 2 are formed at a constant pitch. A nozzle plate 3, a pressure generating chamber 4 communicating with the nozzle opening 2, a flow path forming substrate 7 having a reservoir 6 for supplying ink to the pressure generating chamber 4 through an ink supply port 5, and a longitudinal vibration mode of the piezoelectric vibration unit 8. An elastic plate 10 that abuts on the tip of each piezoelectric vibrator 9 to expand and reduce the volume of the pressure generating chamber 4 is integrally laminated. The flow path unit 1 is connected to an opening surface 12 of a holder 11 formed by injection molding of a polymer material or the like, and the piezoelectric vibration unit 8 is connected to a flexible cable 13 for transmitting an external drive signal. The recording head is housed in the housing chamber 14, and the contact surface with each holder 11 is fixed by an adhesive, and a frame 15 also serving as a shield material is inserted into the nozzle plate side. The piezoelectric vibrator 9 in the longitudinal vibration mode has an internal electrode 21 serving as one pole extending from the front end side to a position short of a fixed region with the fixed substrate 16 and an internal electrode 21 serving as the other pole extending from the vicinity of the front end to the rear end. The electrodes 22 are laminated in a sandwich manner with a piezoelectric material 23 interposed therebetween, and one of the internal electrodes 21 is exposed on the front end side and the other internal electrode 22 is exposed on the rear end side, so as to have a piezoelectric constant d31. I have. One internal electrode 21 is provided on a segment electrode 24 having a conductive layer formed from the front end face to the vicinity of the center of the piezoelectric vibrator 9, and the other internal electrode 22 is provided on the center of the piezoelectric vibrator 9 from the rear end face. And is connected to a common electrode 26 having a conductive layer formed so as to have a certain distance 25 from the rear end side of the segment electrode 24. On the other hand, the fixed substrate 16 is formed by forming a metal layer on the surface of a conductive material, for example, rustless steel or ceramics. The piezoelectric vibrator 9 is fixedly aligned and is conductively connected to a conductive surface 26b formed so as to extend from the rear end surface 26a of the common electrode 26 of the piezoelectric vibrator 9 to the fixed substrate 16 side. At least one end of the row of the piezoelectric vibrators 9 has the same structure as that of the piezoelectric vibrator 9 as shown in FIGS. An internal electrode 21 which is one pole extending to the front
And an internal electrode 22 serving as the other pole extending from the vicinity of the front end to the rear end, are laminated in a sandwich shape via a piezoelectric material 23, and one internal electrode 21 is on the front end side and the other internal electrode 22 is on the rear end. The inner electrode 21 is further exposed to the segment electrode 24 having a conductive layer formed from the tip end face to the vicinity of the center of the piezoelectric vibrator 9, and the other internal electrode 22 is formed.
Is connected to a common electrode 26 having a conductive layer formed so as to have a fixed distance 25 from the rear end face to the center of the piezoelectric vibrator 9 and to the rear end side of the segment electrode 24. Also, a dummy piezoelectric vibrator 9 'formed slightly wider is fixed. The segment electrode 24 and the common electrode 26 of each piezoelectric vibrator 9 of the vibrator unit 8 are connected to the conductive pattern of the flexible cable 13 via solder layers 28 and 29. As shown in FIG. 5, the flexible cable 13 has a grounding conductive pattern 3 corresponding to the width of the dummy piezoelectric vibrators 9 ', 9' at both ends of the vibrator unit 8.
1, 31 and conductive patterns 32 for supplying drive signals corresponding to the segment electrodes 24 of the piezoelectric vibrators 9, 9, 9 #,
32, 32,... Are formed on the base material 33. In this embodiment, when a drive signal is supplied from an external drive circuit via the flexible cable 13, the piezoelectric vibrator 9 for ejecting ink droplets passes through the conductive pattern 32 of the flexible cable 13 and the segment electrode 24. A drive signal is received by the internal electrode 21 serving as one pole, and the internal electrode 22 serving as the other pole via the conductive pattern for ground 31, the fixed substrate 16, and the common electrode 26, and the nozzle is displaced by the piezoelectric constant d31. Opening 2
To eject ink droplets. As described above, in each of the piezoelectric vibrators 9, the common electrode 26 is connected in parallel to the fixed substrate 16 by the conductive surface 26b formed by increasing the thickness of the opposing surface of the fixed substrate 16. Therefore, the flexible cable 16 is connected to the ground conductive pattern 31 with a small resistance. Next, a method of manufacturing the above-described piezoelectric vibrator unit 8 will be described with reference to FIGS. A conductive material 41 serving as an internal electrode serving as one pole extending from the front end to the terminal end side of the active region and a conductive material 42 serving as an internal electrode serving as the other pole extending from the rear end to the vicinity of the front end are sandwiched between piezoelectric materials 43. Piezoelectric vibrating plate 4 formed by laminating, drying and firing
4 and 44 are prepared (FIG. 6 (I)). The piezoelectric vibrating plates 44, 44 are opposed to each other with two spacers 45, 45 therebetween so as to form an interval L such that the electrode forming material for external connection can wrap around slightly during vapor deposition. The mask members 46, 46 are fixed to the exposed front and rear surfaces of the plates 44, 44 at the boundary regions between the segment electrodes and the common electrode (FIG. 6 (II)), and the external connection electrode forming material is applied to the entire periphery. The electrode layers 47 and 48 are formed by vapor deposition. In the course of this vapor deposition, the external connection electrode forming material slightly wraps around by the distance L between the two piezoelectric vibration plates 44, 44, and the flat surfaces 44a of the piezoelectric vibration plates 44, 44
Layers 47a and 48a slightly exposed from 44a are formed (FIG. 6 (III)). When the two piezoelectric vibrating plates 44, 44 are separated and the mask members 46, 46 are removed at the stage when the vapor deposition has been completed, the piezoelectric vibrating plates 44, 44 slightly protrude toward the front end surface, one surface, the rear end surface, and the opposing surface side. Two piezoelectric vibrating plates 50, 50 having conductive layers 47, 48 formed substantially only on three surfaces can be obtained (FIG. 6 (IV)). A region where only the other internal electrode 52 is formed, that is, an inactive region is positioned on a metal or a fixed substrate 53 having a conductive layer formed on a fixed surface (FIG. 7 (I)).
Layer 48 exposed from the end surface of piezoelectric vibrating plate 50 to the opposing surface
a is fixed with an adhesive so that a contacts the fixed substrate 53. Then, slits 56, 56, 56,... Are formed from the free end side tip to at least the conductive layer 47 to be the segment electrode and the rear end side of the conductive material 41 by a cutting tool 55 for dicing saw or wire saw. When the vibration region as the piezoelectric vibrator 9 and the region serving as the segment electrode are cut into a comb shape, a piezoelectric vibrator unit is completed. When forming the slits 56, 56, 56,..., Both ends are cut out slightly wide to form slightly wide dummy piezoelectric vibrators 9 ', 9' which are not involved in vibration. Leaving 48 in a continuous state helps to reduce the electrical resistance of the common electrode. According to the present invention as described above,
Parallel to the fixed substrate in the area where the common electrode of the piezoelectric vibrator is thickened
A piezoelectric vibrator unit that can be connected to reduce electrical resistance
It can be manufactured efficiently .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an assembled perspective view showing one embodiment of an ink jet recording head of the present invention. FIG. 2 is a diagram showing a cross-sectional structure of the device. FIG. 3 is a cross-sectional view showing a connection structure between a dummy piezoelectric vibrator of the recording head and a flexible cable. FIGS. 4 (a) and 4 (b) are perspective views showing one embodiment of a piezoelectric vibration unit used for the recording head. FIG. 5 is a diagram showing one embodiment of a flexible cable. FIGS. 6 (I) to (IV) are diagrams showing an electrode forming step in the manufacturing steps of the vibrator unit used for the recording head, respectively. FIGS. 7 (I) to (III) are diagrams showing the steps up to the division step in the manufacturing process of the vibrator unit used for the recording head. FIG. 8 is a sectional view showing an example of a conventional ink jet recording head using a piezoelectric vibrator having a piezoelectric constant d31. [Description of Signs] 1 Flow path unit 8 Vibrator unit 9 Piezoelectric vibrator 9 'Dummy piezoelectric vibrator 13 Flexible cable 16 Fixed substrate 25 Segment electrode 26 Common electrode 26b Conductive surface formed by increasing the end face of the common electrode

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B41J 2/045 B41J 2/055 B41J 2/16 H01L 41/09

Claims (1)

(57) [Claim 1] An internal electrode serving as one of the electrodes, an internal electrode serving as the other of the electrodes, and a piezoelectric material are alternately overlapped, and only one end of each of the internal electrodes is on the tip side, and Two piezoelectric vibrating plates laminated so as to be exposed on the rear end side are overlapped with a spacer interposed therebetween, and a mask material is fixed to a boundary region between the segment electrode and the common electrode on the front surface and the rear surface, and an external connection electrode is formed. A step of depositing a forming material, and a step of separating the two piezoelectric vibrating plates after the deposition, removing the mask material, and fixing an inactive region to a fixed substrate having at least a surface having conductivity by an adhesive. Forming a slit from a free end side tip to at least a rear end of the segment electrode; and a method of manufacturing a piezoelectric vibrator unit for an ink jet recording head.