JP5672285B2 - Piezoelectric element and manufacturing method thereof - Google Patents

Description

  The present invention relates to a piezoelectric element and a method for manufacturing the same.

  A piezoelectric element having a pair of main surfaces facing each other and a side surface extending in a facing direction of the pair of main surfaces so as to connect the pair of main surfaces, and a piezoelectric body made of a piezoelectric ceramic material, and the piezoelectric body And a pair of electrodes respectively disposed on a pair of main surfaces are generally known.

  A hard disk drive (HDD) head suspension using the above-described piezoelectric element as an actuator for driving a slider is known.

  Patent Document 1 listed below discloses a technique for suppressing the separation of piezoelectric ceramic particles (generation of particles) from the side surface of such an HDD head suspension by coating a resin on the side surface of the piezoelectric element of the piezoelectric element. Has been.

International Publication No. 2011/16994

  However, in the HDD head suspension mounted with the piezoelectric element whose side surface of the piezoelectric body is coated with resin, the displacement (expansion / contraction) of the piezoelectric element may be hindered by the influence of the resin coated on the side surface. .

  That is, in order to accurately transmit the displacement of the piezoelectric element, a resin with a high Young's modulus having high rigidity has been adopted as the resin for coating the side surfaces.

  However, when the entire side surface is coated with a resin having a high Young's modulus, the displacement to be transmitted to the suspension is hindered. As described above, a technique for efficiently displacing a piezoelectric element has been conventionally required even when a resin is coated on the side surface of a piezoelectric body in order to suppress the generation of particles.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a piezoelectric element that can be displaced efficiently and a method for manufacturing the same.

  The piezoelectric element according to the present invention includes a pair of main surfaces facing each other, a first pair of side surfaces extending so as to connect the pair of main surfaces and facing each other in the first displacement direction, and the pair of main surfaces. A piezoelectric body having a second pair of side surfaces facing each other in a second displacement direction orthogonal to the first displacement direction, a resin covering the first side pair of the piezoelectric body, and a second A resin having a resin that covers a pair of side surfaces, wherein the resin that covers the first pair of side surfaces and the resin that covers the second pair of side surfaces have different Young's moduli.

  In this piezoelectric element, each side surface is covered with resin so that the Young's modulus of the resin covering the first side pair of the piezoelectric body and the Young's modulus of the resin covering the second side pair are different. . Accordingly, the side surface of the piezoelectric body that requires rigidity can be coated with a resin having a high Young's modulus, and the side surface of a piezoelectric body that requires stretchability can be coated with a resin having a low Young's modulus. That is, the piezoelectric element according to the present invention can be efficiently displaced even when a resin is coated on the side surface of the piezoelectric body in order to suppress the generation of particles.

  Further, in the piezoelectric element according to the present invention, the pair of main surfaces are rectangular, the first displacement direction is the short direction in the pair of main surfaces, the second displacement direction is the longitudinal direction in the pair of main surfaces, The resin that covers the second side pair preferably has a higher Young's modulus than the resin that covers the first side pair.

  When the main surface is rectangular, the Young's modulus of the resin on the side facing in the longitudinal direction that contacts the suspension and transmitting the displacement of the piezoelectric body is increased, and the Young's modulus of the resin on the side facing in the short direction where the displacement is large Can be lowered. That is, in the piezoelectric element according to the present invention, the Young's modulus of the resin covering the side surface of the piezoelectric body can be made appropriate according to the role of the side surface, and can be efficiently displaced.

  In the method for manufacturing a piezoelectric element according to the present invention, a plurality of first grooves arranged in parallel is provided in a first direction on the surface of the piezoelectric substrate, and the first resin is filled in the plurality of first grooves and cured. Providing a plurality of second grooves arranged in parallel in a step and a second direction that intersects the first direction on the surface of the piezoelectric substrate, and filling the plurality of second grooves with a second resin; A step of curing, cutting the portion filled with the first resin along the first direction, and cutting the portion filled with the second resin along the second direction; A piezoelectric body having a first side pair corresponding to the inner side surface of the groove and a second side pair corresponding to the inner side surface of the second groove, and covering the first side pair And the second resin covering the second side surface pair have different Young's moduli.

  The piezoelectric elements manufactured in this method of manufacturing a piezoelectric element are configured so that the Young's modulus of the resin covering the first side surface pair of the piezoelectric body and the Young's modulus of the resin covering the second side surface pair are different from each other. The side of is covered with resin. Accordingly, the side surface of the piezoelectric body that requires rigidity can be coated with a resin having a high Young's modulus, and the side surface of a piezoelectric body that requires stretchability can be coated with a resin having a low Young's modulus. That is, according to the piezoelectric element manufacturing method of the present invention, it is possible to obtain a piezoelectric element that can be displaced efficiently even when a resin is coated on the side surface of the piezoelectric body in order to suppress the generation of particles. it can. In addition, since the first resin is cured by providing the first groove and the second resin is cured by providing the second groove in different steps, the resin covering the different side pairs Young's modulus can be determined freely.

  In the method for manufacturing a piezoelectric element according to the present invention, it is preferable that the first resin and the second resin are the same component. By using resins of the same component, it is not necessary to prepare a plurality of resins, and the resin filling operation can be simplified.

  In the method for manufacturing a piezoelectric element according to the present invention, the first resin and the second resin are preferably different components. By using resins having different components, it is not necessary to change the environment (temperature, etc.) when the first resin is cured and the second resin is cured, and the resin curing operation can be simplified.

  ADVANTAGE OF THE INVENTION According to this invention, the piezoelectric element which can be displaced efficiently, and its manufacturing method can be provided.

1 is a schematic plan view showing a suspension according to an embodiment of the present invention. It is a top view of the base plate shown in FIG. It is a top view of the hinge components shown in FIG. It is a disassembled perspective view of the piezoelectric element mounted in the suspension of FIG. FIG. 5 is a cross-sectional view of the piezoelectric element mounted on the suspension of FIG. 1 taken along the line VV. It is the figure which showed 1 process at the time of producing the piezoelectric element of FIG. It is the figure which showed 1 process at the time of producing the piezoelectric element of FIG. It is the figure which showed 1 process at the time of producing the piezoelectric element of FIG. It is the figure which showed 1 process at the time of producing the piezoelectric element of FIG. It is the figure which showed 1 process at the time of producing the piezoelectric element of FIG.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted.

  A disk apparatus suspension 10 according to an embodiment of the present invention will be described below with reference to FIGS.

  The dual actuator type suspension 10 shown in FIG. 1 includes a load beam 11, a microactuator unit 12, a base plate 13, and a hinge member 14.

  The load beam 11 is made of a metal plate having a spring property with a thickness of, for example, about 100 μm, and a flexure 15 is attached to the load beam 11 at the tip thereof. The flexure 15 is made of a thin plate spring made of metal that is thinner than the load beam 11. A slider 16 constituting a magnetic head is provided at the front end of the flexure 15.

  As shown in FIG. 2, a circular boss hole 21 is formed in the base portion 20 of the base plate 13. Between the base portion 20 and the front end portion 22 of the base plate 13, a pair of openings 23 having a size capable of accommodating a piezoelectric element 40 described later is formed. Between the pair of openings 23, a band-shaped connecting portion 24 is provided that extends in the front-rear direction of the base plate 13 (in the axial direction of the suspension 10). The connecting portion 24 can be bent to some extent in the width direction of the base plate 13 (sway direction indicated by arrow S in FIG. 1).

  A base portion 20 of the base plate 13 is fixed to a tip end portion of an actuator arm driven by a voice coil motor (not shown), and is turned by a voice coil motor. The base plate 13 is made of a metal plate such as stainless steel having a thickness of about 200 μm, for example. In the case of the present embodiment, the actuator base 25 is configured by the base plate 13 and the hinge member 14.

  As shown in FIG. 3, the hinge member 14 includes a base portion 30 that is fixed over the base portion 20 of the base plate 13, a band-shaped bridge portion 31 that is formed at a position corresponding to the connecting portion 24 of the base plate 13, and the base plate 13. It has an intermediate portion 32 formed at a position corresponding to the front end portion 22, a pair of flexible hinge portions 33 that can be elastically deformed in the thickness direction, a tip portion 34 fixed to the load beam 11, and the like. ing. The hinge member 14 is made of a metal plate having a spring property with a plate thickness of, for example, about 50 μm.

  The microactuator unit 12 is mounted with a pair of piezoelectric elements 40 as piezoelectric actuators. Each of the piezoelectric elements 40 has a rectangular flat plate shape, and is housed in the opening 23 of the actuator base 25 so that the longitudinal direction thereof is substantially parallel to the longitudinal direction of the base plate 13 (the axial direction of the suspension 10). Yes.

  Here, the configuration of the piezoelectric element 40 will be described with reference to FIG. For convenience of explanation, the longitudinal direction of the piezoelectric element 40 will be described as the X direction, the lateral direction as the Y direction, and the thickness direction as the Z direction as appropriate.

  The piezoelectric element 40 includes an element body 41 and a pair of electrodes 42A and 42B that cover the element body 41 from the thickness direction (Z direction).

  The element body 41 includes a piezoelectric body 43 and a resin 44.

  The piezoelectric body 43 has a rectangular flat plate shape and is made of a piezoelectric material such as PZT. That is, the piezoelectric body 43 includes an upper surface 43a and a lower surface 43b (a pair of main surfaces) facing each other in the Z direction and four side surfaces (end surfaces) 43c, 43d extending in the Z direction so as to connect the upper surface 43a and the lower surface 43b. 43e, 43f. The four side surfaces 43c, 43d, 43e, and 43f can be distinguished into a first side surface pair 43c and 43d that face each other in the Y direction and a second side surface pair 43e and 43f that face each other in the X direction. it can.

  The resin 44 entirely covers the four side surfaces 43c, 43d, 43e, and 43f of the piezoelectric body 43 so as to surround it. The resin 44 includes a resin 45A that covers end faces 43c and 43d orthogonal to the short direction (Y direction) of the piezoelectric body 43, and a resin 45B that covers end faces 43e and 43f orthogonal to the longitudinal direction (X direction) of the piezoelectric body 43. It consists of The resin 45A and the resin 45B are formed at different timings as described in the manufacturing method described later. The resin 45A and the resin 45B are made of, for example, an epoxy resin, and the material of the resin 45A and the material of the resin 45B may be the same or different. When the resin 45A or the resin 45B is made of an epoxy resin, for example, a bisphenol A type epoxy resin or the like can be adopted as the epoxy resin.

  The resin of the resin 45A covering the first side pair 43c, 43d and the resin of the resin 45B covering the second side pair 43e, 43f are different in Young's modulus.

  The Young's modulus of the resin 45A and the resin 45B is determined according to the roles of the first side surface pair 43c and 43d and the second side surface pair 43e and 43f. Although details will be described later, as shown in FIG. 5, the piezoelectric element 40 is accommodated in the opening 23 of the base plate 13 so that the longitudinal direction thereof is along the front-rear direction of the base plate 13. In this case, the first side surface pair 43 c and 43 d plays a role of accurately transmitting the displacement of the piezoelectric element 40 to the suspension 10. On the other hand, the second side surface pair 43e and 43f greatly expands and contracts when a voltage is applied, and plays a role of displacing the piezoelectric element 40.

  From the roles of the first pair of side surfaces 43c and 43d and the second pair of side surfaces 43e and 43f, a resin having a relatively low Young's modulus is adopted as the resin 45A covering the first pair of side surfaces 43c and 43d. A resin having a relatively high Young's modulus is used as the resin 45B covering the side surface pairs 43e and 43f, and the Young's modulus of the resin 45B covering the second side surface pair 43e and 43f is set to be the resin covering the first side surface pair 43c and 43d. The Young's modulus is higher than 45A.

  In order to make the Young's modulus of the resin 45A and the resin 45B different, the components of the resin 45A and the resin 45B (the type of epoxy resin and the type of curing agent) may be different. In addition, the components of the resin 45A and the resin 45B are the same, and the Young's modulus of the resin 45A and the resin 45B may be made different by changing the temperature at the time of curing. For example, when bisphenol A epoxy resin is cured with an aliphatic polyamine curing agent, the Young's modulus of the cured resin can be 2 GPa when the temperature at curing is 80 ° C., and the cured temperature when the temperature at curing is 120 ° C. The Young's modulus of the resin can be 4 GPa.

  Examples of the resin having a relatively high Young's modulus include epoxy resin, acrylic resin, urethane resin, polyamide, and polyimide. In order to increase the Young's modulus, an inorganic filler such as silica may be added.

  The pair of electrodes 42A and 42B is made of a conductive material such as metal. Each electrode 42A, 42B is formed so as to cover, for example, the upper and lower surfaces of the element body 41 (that is, the upper and lower surfaces of the piezoelectric body 43 and the upper and lower surfaces of the resin 44). As the electrode material, metals such as Au, Ag, Cu, Pt, Cr, Ni, and W can be used.

  According to such a piezoelectric element 40, by applying a voltage between the pair of electrodes 42A and 42B, the piezoelectric body 43 expands and contracts in the longitudinal direction (X direction) and the short direction (Y direction). The entire piezoelectric element 40 expands and contracts in the longitudinal direction (X direction) and the lateral direction (Y direction).

  Next, how the piezoelectric element 40 is mounted on the suspension 10 will be described with reference to FIG.

  When the piezoelectric element 40 is mounted on the suspension 10, the piezoelectric element 40 is accommodated in the opening 23 of the base plate 13 such that the longitudinal direction (X direction) of the piezoelectric element 40 is along the longitudinal direction of the base plate 13 (the axial direction of the suspension 10). . At this time, the front end portion of the piezoelectric element 40 is bonded and fixed by the adhesive 50 so as to be supported by the intermediate portion 32 of the hinge member 14. Similarly, the rear end portion of the piezoelectric element 40 is fixed to the base portion 30 of the hinge member 14. It is fixed with an adhesive 50 so as to be supported.

  In order to apply a voltage between the electrodes 42A and 42B of the piezoelectric element 40, electric wirings (not shown) are provided on the electrodes 42A and 42B, respectively. Note that a conductive adhesive may be used as the adhesive 50 described above, and the adhesive 50 may be used as part of the electrical wiring.

  When the pair of piezoelectric elements 40 are mounted on the suspension 10, the voltage applied to the pair of piezoelectric elements 40 is controlled to expand one piezoelectric element 40 by a predetermined length in the longitudinal direction and the other piezoelectric element 40 can be contracted by a predetermined length in the longitudinal direction. Thus, in the suspension 10, the load beam 11 side can be displaced by a desired amount in the width direction (sway direction S) by controlling the expansion and contraction of each of the pair of piezoelectric elements 40.

  Next, a procedure for manufacturing the piezoelectric element 40 will be described with reference to FIGS.

  When the piezoelectric element 40 is manufactured, first, a piezoelectric substrate 62 to be the piezoelectric body 43 is held on a plate-like or tape-like substrate 60, and as shown in FIG. A plurality of first grooves 62a arranged in parallel at the same interval G1 are formed. The extending direction of the plurality of first grooves 62a corresponds to the longitudinal direction (X direction) of the piezoelectric element 40 to be manufactured, and the interval G1 between the plurality of first grooves 62a is the short direction length of the piezoelectric body 43. It corresponds to (Y direction length). A generally used cutting tool (such as a dicing saw) can be used to form the plurality of first grooves 62 a, and the first groove 62 a is cut to a depth that does not reach the lower surface of the piezoelectric substrate 62.

  Next, as shown in FIG. 7, the upper surface of the piezoelectric substrate 62 is covered with a thermosetting first resin 64 to be the resin 45A by a printing method or the like. Thereby, the first resin 64 is filled in each of the plurality of first grooves 62 a formed on the upper surface of the piezoelectric substrate 62. After filling, the first resin 64 is cured by heating at a predetermined thermosetting temperature (for example, 80 ° C.).

  Subsequently, as shown in FIG. 8, along the direction (Y direction) orthogonal to the extending direction of the plurality of first grooves 62 a on the upper surface of the piezoelectric substrate 62 covered with the first resin 64. A plurality of second grooves 62b arranged in parallel at the same interval G2 are formed. The extending direction of the plurality of second grooves 62b corresponds to the short direction (Y direction) of the piezoelectric element 40 to be manufactured, and the interval G2 between the plurality of second grooves 62b is the length in the longitudinal direction of the piezoelectric body 43. This corresponds to (length in the X direction). As with the formation of the plurality of first grooves 62a, a generally used cutting tool can be used to form the plurality of second grooves 62b, and cutting is performed to substantially the same depth as the plurality of first grooves 62a. At that time, as shown in FIG. 8, the piezoelectric substrate 62 and the resin 64 are integrally cut.

  Then, as shown in FIG. 9, the upper surface of the piezoelectric substrate 62 covered with the first resin 64 is covered with a thermosetting second resin 66 that should become the resin 45B by a printing method or the like. Thereby, the second resin 66 is filled in each of the plurality of second grooves 62b described above. After filling, the second resin 66 is cured by heating at a predetermined thermosetting temperature (for example, 80 ° C.).

  As described above, the first resin 64 (resin 45A) after curing and the second resin 66 (resin 45B) have different Young's moduli. In order to make the Young's modulus of the first resin 64 and the second resin 66 different, the components of the first resin 64 and the second resin 66 (kind of epoxy resin and kind of curing agent) are different. You can do it. Similarly, the components of the first resin 64 and the second resin 66 may be made different by changing the Young's modulus of the first resin 64 and the second resin 66 by, for example, different temperatures during curing. good.

  Further, the piezoelectric substrate 62 is thinned along a plane (XY plane) orthogonal to the thickness direction, for example, by polishing, and a thin plate 68 having a thickness D shown in FIG. 10 is taken out. The thickness D of the thin plate 68 obtained at this time corresponds to the thickness of the piezoelectric body 43 of the manufactured piezoelectric element 40. Since the thin plate 68 is taken out at a position shallower than the grooves 62 a and 62 b formed in the piezoelectric substrate 62, the piezoelectric substrate 62 is partitioned by the resin 64 and the resin 66 in a lattice shape in the thin plate 68.

  Thereafter, electrode films (not shown) to be the electrodes 42A and 42B are formed on the upper and lower surfaces of the thin film 68 by sputtering or plating, and along the intermediate line L1 of the resin 64 and the intermediate line L2 of the resin 66. Cut into a grid to make chips. Thereby, the piezoelectric element 40 shown in FIG. 4 is obtained. After the electrode is formed, it is polarized. For electrode formation, a method such as sputtering, plating, or baking is appropriately selected. Depending on the application, it may be a piezoelectric element array.

  As described above in detail, the piezoelectric element 40 according to the present embodiment connects the pair of main surfaces (the upper surface 43a and the lower surface 43b) facing each other and the pair of main surfaces (the upper surface 43a and the lower surface 43b). And a pair of main surfaces (upper surface 43a and lower surface 43b) and a pair of main surfaces (upper surface 43a and lower surface 43b) are connected to each other in the Y direction (first displacement direction) and with respect to the first displacement direction. A piezoelectric body 43 having a second pair of side faces 43e and 43f facing each other in the orthogonal X direction (second displacement direction), and a resin 45A and a second cover 45A covering the first pair of side faces 43c and 43d of the piezoelectric body 43. A resin 44 having a resin 45B covering the side pairs 43e and 43f of the piezoelectric element 40, wherein the resin 45A covering the first side pair and the resin 45B covering the second side pair have a Young's modulus. Is different.

  In the piezoelectric element 40, the Young's modulus of the resin 45A covering the first side pair 43c, 43d of the piezoelectric body 43 and the Young's modulus of the resin 45B covering the second side pair 43e, 43f are made different. Each side is covered with resin. Accordingly, the first side surface pair 43c and 43d of the piezoelectric body 43 for which rigidity is required is coated with a resin having a high Young's modulus, and the second side surface pair 43e and 43f for which stretchability is required has a low Young's modulus. Can be coated with resin. That is, the piezoelectric element 40 according to the present invention can be efficiently displaced even when a resin is coated on the side surface of the piezoelectric body 43 in order to suppress the generation of particles.

  In the piezoelectric element 40 according to the present embodiment, the pair of main surfaces (the upper surface 43a and the lower surface 43b) are rectangular, and the first displacement direction is the short direction and the second displacement direction of the pair of main surfaces. Is the longitudinal direction of the pair of main surfaces, and the resin 45B covering the second side surface pair 43e, 43f preferably has a higher Young's modulus than the resin 45A covering the first side surface pair 43c, 43d.

  When the main surfaces (the upper surface 43a and the lower surface 43b) are rectangular, the Young's modulus of the resin 45B of the second pair of side surfaces 43e and 43f that are in contact with the suspension 10 and face each other in the longitudinal direction for transmitting the displacement of the piezoelectric body 43 is high. In addition, the Young's modulus of the resin of the first pair of side surfaces 43c and 43d facing each other in the lateral direction with a large displacement can be reduced. That is, in the piezoelectric element 40 according to the present invention, the Young's modulus of the resin covering the side surface of the piezoelectric body 43 can be made appropriate according to the role of the side surface, and can be displaced efficiently.

  In addition, in the method for manufacturing the piezoelectric element 40 according to the present embodiment, a plurality of first grooves 62a arranged in parallel are provided in the first direction on the surface of the piezoelectric substrate 62, and the first grooves 62a are arranged in the first direction. A plurality of second grooves 62b arranged in parallel are provided in the second direction, which is a direction intersecting the first direction on the surface of the piezoelectric substrate 62, and a step of filling and curing the resin 64, and a plurality of second grooves 62b. The step of filling the groove 62b with the second resin 66 and curing, cutting the portion filled with the first resin 64 along the first direction, and the portion filled with the second resin 66 Cutting along the second direction to obtain a piezoelectric body 43 having a first side surface pair 43c, 43d and a second side surface pair 43e, 43f corresponding to the inner surface of the first groove 62a; And the first resin 64 covering the first pair of side surfaces 43c and 43d A second side-to-43e, the Young's modulus of the second resin 66 covering the 43f different.

  The piezoelectric element 40 manufactured by this piezoelectric element manufacturing method includes a Young's modulus of the resin 45A covering the first side pair 43c, 43d of the piezoelectric body 43 and a Young's modulus of the resin 45B covering the second side pair 43e, 43f. Each side is covered with resin so that the rate is different. Accordingly, the first side surface pair 43c and 43d of the piezoelectric body 43 for which rigidity is required is coated with a resin having a high Young's modulus, and the second side surface pair 43e and 43f for which stretchability is required has a low Young's modulus. Can be coated with resin. That is, the piezoelectric element 40 according to the present invention can be efficiently displaced even when a resin is coated on the side surface of the piezoelectric body 43 in order to suppress the generation of particles. Further, since the curing of the first resin 64 by providing the first groove 62a and the curing of the second resin 66 by providing the second groove 62b are performed in different steps, different side pairs are used. The Young's modulus of the resin covering can be freely determined.

  In order to obtain a piezoelectric element 40 coated with a pair of side surfaces with a high Young's modulus resin and another pair of side surfaces with a low Young's modulus resin, a dispenser or the like is used for the individualized piezoelectric elements 40. It is conceivable that coating and curing are repeated for each side. However, this method has a problem that the coating time per piezoelectric element is enormous and the coating state is not uniform. On the other hand, in the manufacturing method according to the present embodiment, by providing the grooves in the piezoelectric substrate 62 before being individualized, different Young's modulus resins are coated on different pairs of side surfaces, and the coating time, It is significant in terms of coating uniformity.

  Moreover, in the manufacturing method of the piezoelectric element 40 according to the present embodiment, since the first resin 64 and the second resin 66 are the same component, it is not necessary to prepare a plurality of resins, and the resin filling operation is performed. It can be simplified.

  Further, in the method for manufacturing the piezoelectric element 40 according to the present embodiment, the first resin 64 and the second resin 66 are different components, so that the first resin 64 and the second resin 66 are cured. It is not necessary to change the environment (temperature etc.) at the time of performing, and the hardening operation | work of resin can be simplified.

  The present invention is not limited to the above-described embodiment, and various modifications can be made.

  For example, when the resin 45A or the resin 45B is an epoxy resin, a bisphenol A type epoxy resin or the like can be used as the epoxy resin. However, the present invention is not limited to this. Use other epoxy resins that have two or more epoxy groups per molecule and can be cured, for example, bisphenol F epoxy resin, bisphenol AD epoxy resin, alicyclic epoxy resin, etc. You can also.

  The epoxy resin that is the resin 45A and the resin 45B may be one cured by an imidazole curing agent (for example, 2ethyl 4-methylimidazole, 2methylimidazole, etc.). In this case, the generation of particles is suppressed.

  Examples of the production method of the present invention will be described below. The present invention is not limited to these examples.

[Example 1]
A piezoelectric substrate 62 (PZT substrate) having a thickness of 0.1 mm and 50 × 50 mm, on which Au electrodes are formed on the upper and lower surfaces and subjected to polarization treatment, is attached to a dicing tape. In order to form the first grooves 62a parallel at a pitch of 1.05 mm, the piezoelectric substrate 62 is cut with a blade having a thickness of 0.1 mm. Then, the first groove 62a is filled with a flexible one-part epoxy resin (AE-400 manufactured by Ajinomoto Fine Techno Co.) with a dispenser. Perform heat curing. The Young's modulus of the cured resin is 8 MPa.

  Next, the piezoelectric substrate 62 is cut with a blade having a thickness of 0.1 mm in order to form a second groove 62b that is orthogonal to the first groove 62a and parallel at a pitch of 1.55 mm (gap G1 = 1.55 mm). To do. Then, the second groove 62b is filled with a bisphenol A epoxy liquid resin mixed with an amine curing agent with a dispenser. Perform heat curing. The Young's modulus of the cured resin is 4 GPa. Then, the filled resin is diced with a blade having a thickness of 0.05 mm, and the piezoelectric resin whose side surface is coated with a resin having a different Young's modulus having a thickness of 0.1 mm and a thickness of 1.0 mm × 1.5 mm. An element is obtained.

[Example 2]
A piezoelectric substrate 62 (PZT substrate) having a thickness of 0.5 mm and 50 × 50 mm is attached to a dicing tape. In order to form the first grooves 62a parallel at a pitch of 1.05 mm, the piezoelectric substrate 62 is cut with a blade having a thickness of 0.1 mm. At this time, a groove is formed leaving 0.3 mm in the thickness direction. Then, the first groove 62a is filled with a flexible one-part epoxy resin (AE-400 manufactured by Ajinomoto Fine Techno Co.) with a dispenser. Perform heat curing. The Young's modulus of the cured resin is 8 MPa.

  Next, the piezoelectric substrate 62 is cut with a blade having a thickness of 0.1 mm in order to form a second groove 62b that is orthogonal to the first groove 62a and is parallel at a pitch of 1.55 mm (gap G2 = 1.55 mm). To do. At this time, a groove is formed leaving 0.2 mm in the thickness direction. Then, the second groove 62b is filled with a bisphenol A epoxy liquid resin mixed with an amine curing agent with a dispenser. Perform heat curing. Then, the upper surface is polished by 0.1 mm and the lower surface is polished by 0.3 mm, and the remaining portion of the PZT substrate is removed. Au is sputtered on the upper and lower surfaces to form electrodes, and polarization treatment is performed. The Young's modulus of the cured resin is 4 GPa. Then, the filled resin is diced with a blade having a thickness of 0.05 mm, and the piezoelectric resin whose side surface is coated with a resin having a different Young's modulus having a thickness of 0.1 mm and a thickness of 1.0 mm × 1.5 mm. An element is obtained.

DESCRIPTION OF SYMBOLS 10 ... Suspension, 40 ... Piezoelectric element, 42A, 42B ... Electrode, 43 ... Piezoelectric body, 43a ... Upper surface, 43b ... Lower surface, 43c, 43d, 43e, 43f ... Side surface, 44, 45A, 45B ... Resin, 62 ... Piezoelectric substrate 62a, first groove, 62b, second groove, 64, first resin, 66, second resin.

Claims (6)

A pair of main surfaces facing each other, a first side surface pair extending in a first displacement direction and facing each other in the first displacement direction, and connecting the pair of main surfaces and the first A piezoelectric body having a second pair of side surfaces facing each other in a second displacement direction orthogonal to the one displacement direction;
A resin having a resin covering the first side surface pair of the piezoelectric body and a resin covering the second side surface pair;
A piezoelectric element comprising:
The resin that covers the second side pair, which requires rigidity compared to the first side pair, is younger than the resin that covers the first side pair, which requires stretchability compared to the second side pair. Piezoelectric element with high rate . The pair of main surfaces are rectangular,
It said first lateral direction in the pair of main surfaces and a displacement direction, said second longitudinal direction in the pair of main surfaces and displacement direction, Ru der piezoelectric element according to claim 1. Providing a plurality of parallel first grooves in a first direction on the surface of the piezoelectric substrate, filling the plurality of first grooves with a first resin, and curing the first resin;
A plurality of second grooves arranged in parallel is provided in a second direction that is a direction intersecting the first direction on the surface of the piezoelectric substrate, and the second resin is filled in the plurality of second grooves and cured. A process of
Cutting the portion filled with the first resin along the first direction, and cutting the portion filled with the second resin along the second direction, thereby Obtaining a piezoelectric body having a first side pair corresponding to the inner side surface of the groove and a second side pair corresponding to the inner side surface of the second groove,
The second resin that covers the second side pair that is required to have rigidity compared to the first side pair covers the first side pair that is required to be stretchable compared to the second side pair. A method for manufacturing a piezoelectric element, wherein the Young's modulus is higher than that of the first resin .   The method for manufacturing a piezoelectric element according to claim 3, wherein the first resin and the second resin are the same component.   The method for manufacturing a piezoelectric element according to claim 3, wherein the first resin and the second resin are different components. The piezoelectric body is formed with a pair of main surfaces facing each other so as to be connected to the first side surface pair and the second side surface pair,
The pair of main surfaces are rectangular,
The piezoelectric element according to any one of claims 3 to 5, wherein the first direction is a longitudinal direction of the pair of main surfaces, and the second direction is a short direction of the pair of main surfaces. Manufacturing method.

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