JP3456515B2 - 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 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 made of gold for the purpose of ensuring easy soldering. I have. 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 has been made in view of such a problem,
Vibration piezoelectric inkjet type recording head has as its object can be to reduce the amount of high-cost electrode materials
The manufacturing method of Doko unit is to propose. [0005] In order to solve such a problem, according to the present invention, a semiconductor device is formed so as to be exposed from one end.
The first internal electrode, which is one of the electrodes, is exposed from the other end.
And the second internal electrode, which is the other pole formed
Alternately with an electrical material and embedded in the piezoelectric material on the surface.
An electrode made of the same material as the internal electrode
The formed piezoelectric vibrating plate is embedded in the piezoelectric material and shaped.
An electrode made of the same material as the internal electrode
Two sheets are superimposed and share 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;
Formed by separating the diaphragm and embedding it in the piezoelectric material
At least the surface leads an electrode made of the same material as the internal electrode.
A process of fixing with an adhesive to a fixed substrate having electrical conductivity;
Slit at least in the range of the active area from the tip on the end side
Forming step. A common electrode is connected in parallel to a fixed substrate having conductivity through an exposed internal electrode to reduce the electric resistance, so that the common electrode formed on the piezoelectric vibrator is formed on only two surfaces. Make it possible to shape. 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 vicinity of the front end to the rear end, and an internal electrode 21 serving as the other pole extending from the front end side to a position short of a fixing region with the fixed substrate 16. The electrodes 22 are laminated in a sandwich manner via a piezoelectric material 23, one internal electrode 21 is exposed at the rear end side, and the other internal electrode 22 is exposed at the front end side to have a piezoelectric constant d31. ing. The internal electrode 21 serving as one pole is formed by a common electrode 24 having a conductive layer formed so as to extend from the rear end surface to the center of the piezoelectric vibrator 9. It is connected to a segment electrode 26 formed by forming a conductive layer so as to have a certain distance 25 from the tip surface to the tip side of the common electrode 24. On the surface of the piezoelectric vibrator 9 facing the fixed substrate 16, an internal electrode 21 serving as one pole is provided.
An electrode layer 27 having the same shape as that of the internal electrode 21 and made of the same material as the internal electrode 21 is formed so as to have a conductive relationship with the common electrode 24. The fixed substrate 16 is formed by forming a metal layer on the surface of a conductive material, for example, rustless steel or ceramics, and the piezoelectric vibrators 9 are arranged on the surface of the metal layer so as to match the arrangement pitch of the pressure generating chambers 4. At the same time, the rear end face 24 a of the common electrode 24 of the piezoelectric vibrator 9 is electrically connected to the fixed substrate 16 via the electrode 27. At least one end of the row of the piezoelectric vibrators 9 has the same structure as the piezoelectric vibrator 9 as shown in FIGS. 3 and 4, ie, one pole extending from the vicinity of the front end to the rear end. And the fixed substrate 16 from the tip side.
And an internal electrode 22 serving as the other pole extending to a position just before the fixed region with the other electrode in a sandwich shape via a piezoelectric material 23. One internal electrode 21 is exposed at the rear end side, and the other internal electrode 22 is It is exposed on the front end side, and one internal electrode 21 has a constant distance 25 from the rear end surface to the center of the piezoelectric vibrator 9, and the other internal electrode 22 has a fixed distance 25 from the front end surface to the front end side of the common electrode 24. A dummy piezoelectric vibrator 9 ′ which is connected to a segment electrode 26 having a conductive layer formed thereon and is formed to be slightly wider than the piezoelectric vibrator 9 is fixed. Then, similarly to the piezoelectric vibrator 9, the fixed substrate 16
An electrode layer 27 having the same shape as the internal electrode 21 serving as one of the poles and made of the same material as the internal electrode 21 is formed on the surface facing the common electrode 24 so as to have a conductive relationship with the common electrode 24. The common electrode 24 and the segment 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 26 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 26. To the internal electrode 22 serving as the other electrode, the ground conductive pattern 31, the fixed substrate 16, the electrode layer 2
7 and one internal electrode 2 via the common electrode 24
1 receives a drive signal, and causes an ink droplet to be ejected from the nozzle opening 2 by displacement caused by the piezoelectric constant D31. As described above, each of the piezoelectric vibrators 9 has the common electrode 24 of the fixed substrate 1 having conductivity by the electrode layer 27.
6 is connected in parallel with the ground conductive pattern of the flexible cable 16 with a small resistance. In addition, the outermost piezoelectric material 23 'can also contribute to the displacement, and the displacement efficiency can be increased. 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 rear end to the vicinity of the front end
Is exposed from the surface, and thereafter, a conductive material 41 serving as an internal electrode serving as one pole and a conductive material 42 serving as an internal electrode serving as the other pole extending from the front end to the end side of the active region are sandwiched by a piezoelectric material 43. Two piezoelectric vibrating plates 44, 44 formed by laminating while drying and firing after drying are prepared (FIG. 6).
(I)). The two piezoelectric vibrating plates 44, 44 are overlapped so that the exposed conductive material 41 'is on the inside, and a mask is formed on the exposed front and back surfaces of the boundary region between the segment electrode and the common electrode. The members 45, 45 are fixed (see FIG. 4 (I
I)), an electrode forming material for external connection is vapor-deposited over the entire periphery to form electrode layers 46 and 47 (FIG. 4 (III)). When the two piezoelectric vibrating plates 44, 44 are separated and the mask materials 45, 45 are removed at the stage when the vapor deposition is completed, the conductive layer is formed only on the three surfaces of the front surface, the rear surface, and one surface. Are formed, and two piezoelectric vibrating plates 5 whose rear ends of the exposed conductive material 41 'are electrically connected to the conductive layer are formed.
0 and 50 can be obtained (FIG. 4 (IV)). A region in which only one internal electrode 51 is formed, ie, an inactive region, is fixed with a metal or a fixed substrate 53 having a conductive layer formed on the surface (FIG. 7I) with an adhesive. (FIG. 7 (II)). As a result, the exposed conductive layer 41 'forms a conductive relationship with the fixed substrate 53. Next, slits 56, 56, 56,... Are formed from the tip on the free end side to at least the conductive layer 47 to be a segment electrode and the rear end side of the conductive material 41 by a dicing saw or wire saw cutting tool 55. Then, 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 (FIG. 7 (III)). 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 47 in a continuous state helps to reduce the electric resistance of the common electrode. As described above, according to the present invention ,
Is the same material as the internal electrode formed by embedding in the piezoelectric material?
Electrodes on the surface to form a conductive fixed substrate
Piezoelectric vibrator unit with reduced electrical resistance by connecting more in parallel
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 24 common electrode 26 segment electrode 27 conductive layer

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-181869 (JP, A) JP-A-6-320726 (JP, A) JP-A-5-84907 (JP, A) JP-A-4-184 368852 (JP, A) (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] A first internal electrode which is formed to be exposed from one end and serves as one pole, and a first internal electrode which is formed to be exposed from the other end and serves as a second electrode. 2, an internal electrode and a piezoelectric material are alternately overlapped, and a piezoelectric vibrating plate having an electrode made of the same material as the internal electrode formed on the surface of the piezoelectric material is formed by embedding the piezoelectric material in the piezoelectric material. Depositing two electrodes made of the same material as the internal electrodes facing each other, fixing the mask material in the boundary region between the segment electrode and the common electrode on the front and back surfaces, and depositing the external connection electrode forming material. Separating the two piezoelectric vibrating plates after vapor deposition, and fixing an electrode made of the same material as the internal electrode formed by embedding the piezoelectric material to a fixed substrate having at least a surface having conductivity with an adhesive; Free end side Process and method for manufacturing a piezoelectric vibrator unit for an ink jet recording head consisting of forming a slit in the range of at least the active region from the edge.