JP3467579B2 - Manufacturing method of piezoelectric vibrator unit - 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 used in 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 has been made in view of such a problem, and an object of the present invention is to provide an ink jet type that can reduce the use fee of expensive electrode materials by using three electrode layers for external connection. Recording head pressure
It is to propose a method for producing a photoelectric transducer unit. [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.
Two piezoelectric vibrating plates stacked in
Boundary area between segment electrode and common electrode on front and back
The mask material is fixed on the substrate and the electrode forming material for external connection is deposited.
And separating the two piezoelectric vibrating plates after vapor deposition.
The inactive region is removed at least from the surface by removing the mask material
A step of fixing with an adhesive to a fixed substrate having conductivity,
Conductive connection between fixed end face and fixed substrate by conductive bonding
And at least the segment from the free end.
Yusuke forming a slit to the rear end of the cement electrodes, the
You. The common electrode of the piezoelectric vibrator is formed by connecting the common electrode formed on the piezoelectric vibrator by reducing the electrical resistance by connecting the common electrode of the piezoelectric vibrator in parallel to a conductive fixed substrate by conductive bonding means. It is possible to form only on the surface. 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. In addition to being fixed so as to coincide with each other, the rear end face 26a of the common electrode 26 of the piezoelectric vibrator 9 is conductively connected to the rear end surface 26a of the piezoelectric vibrator 9 by a conductive bonding portion 27 of a conductive adhesive or a solder paste. 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. The drive signal is received by the internal electrode 21 serving as one of the electrodes, and the internal electrode 22 serving as the other electrode via the ground conductive pattern 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, since each of the piezoelectric vibrators 9 has its common electrode 26 connected to the fixed substrate 16 having conductivity by the conductive bonding portion 27 of the solder paste and is connected in parallel, the piezoelectric vibrator 9 is flexible with a small resistance. It will be connected to the ground conductive pattern of the cable 16. 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 end side of the active region and a conductive material serving as an internal electrode serving as the other pole extending from the rear end to the vicinity of the tip are sandwiched between piezoelectric materials 43. Two piezoelectric vibrating plates 44, 44 formed by laminating, drying and firing are prepared (FIG. 6 (I)). The two piezoelectric vibrating plates 44 are overlapped with each other, and the mask members 45, 45 are fixed to the exposed front and rear surfaces in the boundary region between the segment electrode and the common electrode (FIG. 4).
(II)), an electrode forming material for external connection is vapor-deposited over the entire circumference to form electrode layers 46 and 47 (FIG. 4 (III)). When the two piezoelectric vibrating plates 44, 44 are separated and the mask members 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. Can be obtained (FIG. 4 (IV)). A region in which only the other internal electrode 52 is formed, that is, an inactive region, is fixed to a metal or a fixed substrate 53 having a conductive layer formed on a fixed surface (FIG. 7 (I)). Then, the end face 50a of the piezoelectric vibrating plate 50 and the fixed substrate 53 are conductively connected by a conductive adhesive or a solder paste 54. Then, slits 56, 56, 56,... Are formed from the tip on the free end side to at least the conductive layer 46 serving as a 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 47 in a continuous state helps to reduce the electric resistance of the common electrode. The above, according to the present invention Oite to the present invention as described
Is that at least the fixed surface of the piezoelectric vibrator on the fixed substrate is conductive
And is bonded to the front end face of the piezoelectric vibrator and the fixed substrate.
Electrically independent of adjacent piezoelectric vibrator
The segment electrode is at a fixed distance from the segment electrode
On the surface that is not bonded to the fixed substrate and the rear end surface
A common electrode is formed and fixed to the common electrode formed on the rear end face.
Since the conductive substrate and the fixed substrate are electrically connected by the conductive bonding means , the common electrode of the piezoelectric vibrator can be connected in parallel to the conductive fixed substrate by the conductive bonding means to reduce the electric resistance.
With only two common electrodes formed on the piezoelectric vibrator, the area for forming the external connection electrodes can be reduced to reduce the cost.

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 Segment electrode 26 Common electrode 27 Conductive joint 27

──────────────────────────────────────────────────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, and a mask material is fixed to the boundary region between the segment electrode and the common electrode on the front surface and the back surface, and the electrode forming material for external connection is deposited. A step of separating the two piezoelectric vibrating plates after vapor deposition, removing the mask material, and fixing an inactive region to a fixed substrate having at least a surface having conductivity by an adhesive; A step of conductively connecting the substrate and the fixed substrate by conductive bonding, and a step of forming a slit from a free end side end to at least a rear end of the segment electrode.