JP2019145732A - Device manufacturing method, piezoelectric device manufacturing method, and electrode pad manufacturing method - Google Patents

Abstract

To manufacture a device while guaranteeing good bond strength in wire bonding, and reducing man-hours.SOLUTION: A device manufacturing method includes a removal process (S11-S14) for removing a second electrode layer 122 from a layer structure member 15, where the second electrode layer 122 is provided while sandwiching a piezoelectric layer 121 between a first electrode layer 112 and the second electrode layer, while leaving a device part 12 and an electrode pad 13 separated from the device part 12, and an electrification process (S15-S17) for electrifying a first electrode layer 112 and the second electrode layer 122 in the electrode pad 13.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a device manufacturing method, a piezoelectric device manufacturing method, and an electrode pad manufacturing method.

  Conventionally, a piezoelectric device that generates a driving force using a piezoelectric body is known. In such a piezoelectric device, a first electrode layer and a second electrode layer are formed with a piezoelectric layer interposed therebetween. By applying a drive signal to the piezoelectric layer through these electrode layers, the piezoelectric layer is configured to expand and contract to generate a driving force. A metal layer such as gold or platinum is used as the electrode layer as described above (for example, see Patent Document 1).

  Here, wire bonding may be used for wiring to the electrode layer in the piezoelectric device. At this time, in order to facilitate wire bonding, an island-shaped device in which a second electrode layer is formed on a widely formed first electrode layer with a piezoelectric layer interposed between the first electrode layer and the first electrode layer. Part may be formed. According to such a configuration, it is possible to perform wire bonding from the same direction on the second electrode layer in the device portion and the first electrode layer extending from the device portion, which is convenient.

  From the viewpoint of wire bonding strength in wire bonding, it is desirable that the electrode layer to be bonded is formed of a metal that is easily compatible with the wire, such as gold. In the case of the piezoelectric device as described above, the second electrode layer formed on the piezoelectric layer has a high degree of freedom in forming material, and can be formed of the above-described desirable metal. On the other hand, the first electrode layer, which is the lower layer of the piezoelectric layer, must be formed of a metal that is not easily compatible with wires in wire bonding, such as platinum, in order to satisfactorily form the piezoelectric layer. You may not get. In such a case, an electrode pad is formed on the first electrode layer with a metal that is easily compatible with the wire. By providing such an electrode pad, good bonding strength can be obtained also for the first electrode layer.

JP 2017-108125 A

  However, in the piezoelectric device in which the electrode pad is formed on the first electrode layer as described above, the process for forming the electrode pad is necessary separately from the process for forming the device portion in the manufacture thereof, and the man-hours correspondingly. Will increase.

  Heretofore, the situation that man-hours are increased by separately forming electrode pads for wire bonding has been described by taking a piezoelectric device as an example. However, such a situation is not limited to a piezoelectric device, and generally occurs in a device having a device portion in which an electrically driven element layer is sandwiched between a first electrode layer and a second electrode layer. obtain. More generally, this is also the case with electrode pads that apply drive signals to such device portions.

  Accordingly, an object of the present invention is to provide a device manufacturing method, a piezoelectric device manufacturing method, and an electrode pad manufacturing method that can be manufactured with a reduced man-hour while ensuring good bonding strength for wire bonding. Is given as an example.

  In order to solve the above-mentioned problems and achieve the object, the device manufacturing method according to claim 1 includes a second electrode layer sandwiching an electrically driven element layer between the second electrode layer and the first electrode layer. Removing the second electrode layer from the layer structure member provided with a predetermined device portion and an electrode pad spaced apart from the device portion, and removing the second electrode layer from the first electrode layer and the electrode pad. And an energization step of energizing the second electrode layer.

1 is a schematic diagram illustrating a piezoelectric device according to a first embodiment of the present invention. 2 is a manufacturing flow schematically showing a piezoelectric device manufacturing method for manufacturing the piezoelectric device shown in FIG. 1. It is a schematic diagram which shows the modification of 1st Example demonstrated with reference to FIG.1 and FIG.2. It is a schematic diagram which shows the piezoelectric device which concerns on 2nd Example of this invention. It is a figure which shows the comparative example for comparing with both the piezoelectric device of 1st Example shown by FIG. 1, and the piezoelectric device of 2nd Example shown by FIG.

  Embodiments of the present invention will be described below. A device manufacturing method according to an embodiment of the present invention includes a removal step and an energization step. The removing step includes a predetermined device portion and an electrode pad spaced apart from the device portion from the layer structure member provided with the second electrode layer with the electrically driven element layer sandwiched between the first electrode layer , Leaving the second electrode layer. The energizing step is a step of energizing the first electrode layer and the second electrode layer in the electrode pad.

  According to the device manufacturing method of the present embodiment, the electrode pad in the manufactured device has a laminated structure equivalent to the device portion. For this reason, the wire bonding to the electrode pad is performed on the second electrode layer located in the upper layer, similarly to the wire bonding to the device portion. Since the second electrode layer is energized to the first electrode layer, wire bonding to the electrode pad as described above has substantially the same electrical effect as wire bonding to the first electrode layer. At this time, since the second electrode layer has a higher degree of freedom in forming material than the first electrode located in the lower layer of the element layer, it is possible to obtain good bonding strength. And since an electrode pad is formed together with a device part through the above-mentioned removal process and energization process, it becomes possible to suppress a man-hour. As described above, according to the device manufacturing method of the present embodiment, it is possible to manufacture a device with a reduced man-hour while ensuring good bonding strength for wire bonding.

  Here, in the device manufacturing method of the present embodiment, the energization step may be a step of removing the element layer so that a part of the second electrode layer hangs down to reach the first electrode layer with respect to the electrode pad. According to this, since the current-carrying portion can be formed together with the electrode pad, the device can be manufactured with further reduced man-hours.

  Further, in the device manufacturing method of the present embodiment, the energization step includes the step of removing the element layer corresponding to the second electrode layer removed in the removal step, and the second electrode layer and the first electrode layer in the electrode pad. And a step of applying a conductive adhesive. According to this, since the current-carrying part can be formed by a simple method of applying a conductive adhesive, it is possible to manufacture a device while suppressing a decrease in yield.

  Moreover, the piezoelectric device manufacturing method which concerns on embodiment of this invention is equipped with a layer structure formation process, a removal process, and an electricity supply process. In the layer structure forming step, the second electrode layer is sandwiched between the first electrode layer and the substrate having the plate-like substrate and the first electrode layer formed on the surface of the substrate. It is the process of forming the layer structure member provided with. The removing step is a step of removing the second electrode layer from the layer structure member leaving a predetermined device portion and an electrode pad spaced apart from the device portion. The energizing step is a step of energizing the second electrode layer in the electrode pad and the first electrode layer in the substrate.

  According to the piezoelectric device manufacturing method of the present embodiment, since the electrode pad having a laminated structure equivalent to the device portion is formed together with the device portion, man-hours can be reduced while ensuring good bonding strength for wire bonding. A device can be manufactured while suppressing.

  In addition, the electrode pad manufacturing method according to the embodiment of the present invention includes a step of forming a second electrode layer with an electrically driven element layer sandwiched between the first electrode layer on the substrate and the second electrode. Energizing the layer and the first electrode layer.

  According to the electrode pad manufacturing method of the present embodiment, the manufactured electrode pad has a laminated structure in which the second electrode layer is formed with the element layer interposed between the electrode pad and the first electrode layer. For this reason, wire bonding to the manufactured electrode pad is performed on the second electrode layer located in the upper layer. Since the second electrode layer is energized to the first electrode layer, wire bonding to the electrode pad as described above means wire bonding to the first electrode layer. At this time, since the second electrode layer has a higher degree of freedom in forming material than the first electrode located in the lower layer of the element layer, it is possible to obtain good bonding strength. Since the electrode pad has the above laminated structure, for example, in manufacturing a device in which this electrode pad is combined with a device part having a laminated structure equivalent to this electrode pad, the electrode pad is combined with the device part. This makes it possible to reduce the man-hours. As described above, according to the electrode pad manufacturing method of the present embodiment, it is possible to manufacture with a reduced man-hour while ensuring good bonding strength for wire bonding.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. First, the first embodiment will be described.

  FIG. 1 is a schematic view showing a piezoelectric device according to a first embodiment of the present invention. The top view of FIG. 1 shows a plan view of the piezoelectric device 1, and the bottom row shows a cross-sectional view of the piezoelectric device 1 along the line V11-V11.

  A piezoelectric device 1 shown in FIG. 1 generates a driving force using a piezoelectric body, and includes a substrate 11, a device unit 12, an electrode pad 13, and a current-carrying unit 14.

  The substrate 11 includes a plate-like base 111 made of silicon, and a first electrode layer 112 made of platinum on an oxide film 111a on the surface of the base 111.

  The device unit 12 is formed by forming a second electrode layer 122 of gold on a substrate 11 with a piezoelectric layer 121 serving as an electrically driven element layer between the first electrode layer 112 and the first electrode layer 112. It is. In the present embodiment, as shown in the upper plan view of FIG. 1, the device portion 12 is formed so that the piezoelectric layer 121 is wider than the second electrode layer 122 in the plan view. Then, the first wire BW1 is bonded to the second electrode layer 122, which is located above the piezoelectric layer 121 in the device portion 12 and formed of gold, by wire bonding.

  The electrode pad 13 is a rectangular island-like portion formed on the substrate 11 so as to be separated from the device portion 12 in a plan view, and has a laminated structure equivalent to the device portion 12. That is, similarly to the device portion 12, the electrode pad 13 has a second electrode layer 122 made of gold with a piezoelectric layer 121 sandwiched between the electrode layer 13 and the first electrode layer 112. Then, the second wire BW2 is bonded to the second electrode layer 122, which is located above the piezoelectric layer 121 in the electrode pad 13 and formed of gold, by wire bonding.

  The energization unit 14 energizes the second electrode layer 122 in the electrode pad 13 and the first electrode layer 112 in the substrate 11. In the present embodiment, the energization unit 14 reaches the first electrode layer 112 by a part of the second electrode layer 122 in the electrode pad 13 extending and hanging down over the entire outer periphery of the rectangular plan view outline. It has become a thing. Since the second electrode layer 122 in the electrode pad 13 is energized to the first electrode layer 112 by the energization portion 14, the wire bonding to the electrode pad 13 as described above is the same as the wire bonding to the first electrode layer 112 and the electric bonding. The effect is almost the same.

  In the piezoelectric device 1 described above, a drive signal is applied to the piezoelectric layer 121 by wire bonding to the second electrode layer 122 in the device portion 12 and wire bonding to the second electrode layer 122 in the electrode pad 13. Wiring for this purpose is performed.

  FIG. 2 is a manufacturing flow schematically showing a piezoelectric device manufacturing method for manufacturing the piezoelectric device shown in FIG. In FIG. 2, each stage in the manufacturing flow is shown in a cross-sectional view corresponding to the cross-sectional view of the piezoelectric device 1 shown in the lower part of FIG.

  The first step (S11) of the manufacturing flow is as follows, on the substrate 11 on which the first electrode layer 112 is formed of platinum on the oxide film 111a on the surface of the plate-like substrate 111 made of silicon. This is a layer structure forming step for forming the layer structure member 15. The layer structure member 15 is configured such that the second electrode layer 122 is formed of gold with the piezoelectric layer 121 interposed between the first electrode layer 112 and the first electrode layer 112.

  The second step (S12), the third step (S13), and the fourth step (S14) following the first step (S11) are the following removal steps. The removing step is a step of removing the second electrode layer 122 from the layer structure member 15 while leaving the device portion 12 and the electrode pad 13 shown in FIG.

  First, in the second step (S12), a resist mask 16 is formed so as to mask the device portion 12 and the electrode pad 13. In the next third step (S13), an etching process is performed, and the second electrode layer 122 is removed leaving the region where the resist mask 16 is formed. In the fourth step (S14), the resist mask 16 is removed.

  The fifth step (S15), the sixth step (S16), and the seventh step (S17) following the fourth step (S14) are the following energization steps. The energizing step is a step of energizing the second electrode layer 122 in the electrode pad 13 and the first electrode layer 112 in the substrate 11. Here, in this embodiment, this energization step is a step of removing the piezoelectric layer 121 so that part of the second electrode layer 122 hangs down to reach the first electrode layer 122 with respect to the electrode pad 13. .

  First, in the fifth step (S15), the resist mask 17 is formed so as to leave the piezoelectric layer 121 that becomes a part of the electrode pad 13 and the piezoelectric layer 121 that becomes a part of the device unit 12. The resist mask 17 at this time covers the second electrode layer 122 left in the fourth step (S14), and is formed so as to slightly protrude from the outer periphery of the second electrode layer 122 on the device portion 12 side. The

  In the next sixth step (S16), an etching process is performed to remove the piezoelectric layer 121. The etching at this time is performed over an etching time such that the inner part of the portion covered with the resist mask 17 is eroded to some extent. As a result of the etching, the rectangular block-shaped piezoelectric layer 121 is left on the electrode pad 13 side so that the second electrode layer 122 that hangs down as the energizing portion 14 is projected to the periphery as described later.

  On the device portion 12 side, the piezoelectric layer 121 corresponding to the lower portion of the resist mask 17 protruding as described above is removed. With this removal, as shown in FIG. 1, a piezoelectric layer 121 slightly wider than the second electrode layer 122 in the plan view is formed in the device portion 12.

  The etching time in the sixth step (S16) is the time for the second electrode layer 122 of the electrode pad to have a shape that protrudes from the piezoelectric layer 121 in a subsequent step and is wide enough to form the energizing portion 14. Is set to At this time, the same amount of the piezoelectric layer 121 as that on the electrode pad side is also removed on the device unit 12 side. In the fifth step (S15), the piezoelectric layer 121 of the device unit 12 is removed at this time so that the second electrode layer 122 of the device unit 12 does not hang down toward the first electrode layer 112. On the device portion 12 side, the resist mask 17 is formed to be wide in the shape of overhanging as described above.

  Finally, in the seventh step (S17), the resist mask 17 is removed. The removal of the resist mask 17 at this time is performed by a wet method using a solvent. As a result, the second electrode layer 122 on the electrode pad 13 side protruding from the piezoelectric layer 121 hangs downward. Then, the rectangular block-shaped piezoelectric layer 121 is firmly attached to the first electrode layer 112 from the four side surfaces by surface tension. The energization part 14 is formed by this sticking.

  In the present embodiment, in the removal process from the second step (S12) to the fourth step (S14), the second electrode layer is widened on the electrode pad 13 side, including the portion that functions as the energizing portion 14. A resist mask 16 is formed so as to leave 122.

  By the seventh step (S17), the device portion 12 having the piezoelectric layer 121 and the second electrode layer 122 on the substrate 11, the electrode pad 13 having the same laminated structure, and the electrode pad 13 The energization unit 14 for energizing the first electrode layer 112 through the two-electrode layer 122 is completed. That is, the seventh step (S17) completes the piezoelectric device 1 shown in FIG. 1, and the piezoelectric device manufacturing method in the present embodiment is completed.

  Next, a modification of the first embodiment described with reference to FIGS. 1 and 2 will be described. In this modification, the shape of the energization portion is different from the shape of the energization portion 14 in the first embodiment.

  FIG. 3 is a schematic diagram showing a modification of the first embodiment described with reference to FIGS. 1 and 2. FIG. 3 shows the energization unit 141 in the modification by showing three steps corresponding to the energization process from the fifth step (S15) to the seventh step (S17) shown in FIG. ing.

  First, in the removing step up to the fifth modified step (S151), the second electrode layer 122 is formed on the side of the electrode pad 131 from the rectangular region to be wire-bonded so as to function as the energization unit 141. The second electrode layer 122 extending in a shape and the piezoelectric layer 121 therebelow are left. In the fifth modified step (S151), a resist mask 171 is formed so as to cover the remaining second electrode layer 122, and subsequently, the piezoelectric layer 121 is etched. FIG. 3 shows a state in which the piezoelectric layer 121 is removed until the portion immediately below the resist mask 171 remains in the fifth modified step (S151).

  Etching of the piezoelectric layer 121 is continued in the sixth modified step (S161) following the fifth modified step (S151). The etching here is performed until the piezoelectric layer 121 under the second electrode layer 122 extending in a branch shape is removed. The degree of such etching is controlled by appropriately adjusting the etching time.

  Finally, in a modified seventh step (S171), the resist mask 17 is removed by a wet method using a solvent. Through the above steps, the branch-like portion of the second electrode layer 122 hangs downward from the rectangular block-shaped piezoelectric layer 121 and sticks to the first electrode layer 112 as described above. The branching portion of the second electrode layer 122 is attached until the first electrode layer 112 is reached, and the energization portion 114 is reliably formed.

  Next, a second embodiment will be described. In the second embodiment, the energization portion is different from the first embodiment and the modification described above. Hereinafter, the second embodiment will be described by paying attention to the energizing portion that is different from the first embodiment.

  FIG. 4 is a schematic view showing a piezoelectric device according to a second embodiment of the present invention. The top view of FIG. 4 shows a plan view of the piezoelectric device 2, and the bottom row shows a cross-sectional view of the piezoelectric device 2 along the line V21-V21. In FIG. 4, the same components as those of the piezoelectric device 1 of the first embodiment shown in FIG. 1 are denoted by the same reference numerals as those in FIG. A duplicate description of the components is omitted.

  The piezoelectric device 2 shown in FIG. 4 includes a substrate 11 in which a platinum first electrode layer 112 is formed on an oxide film 111a of a silicon base 111, as in the first embodiment. ing. The device part 22, the electrode pad 23, and the energizing part 24 are formed on the first electrode layer 112 in the substrate 11.

  Here, in this embodiment, the piezoelectric layer 221 and the second electrode layer 222 in the device portion 22 are formed in the same shape in plan view. Similarly, the piezoelectric layer 221 and the second electrode layer 222 in the electrode pad 23 are also formed in the same shape in plan view. The first wire BW1 is bonded to the second electrode layer 222, which is located above the piezoelectric layer 221 in the device portion 22 and formed of gold, by wire bonding. In addition, the second wire BW2 is bonded to the second electrode layer 222, which is located above the piezoelectric layer 221 in the electrode pad 23 and made of gold, by wire bonding.

  The energizing portion 24 is a conductive adhesive applied across the second electrode layer 222 in the electrode pad 23 and the first electrode layer 112 in the substrate 11.

  In the present embodiment, the current-carrying portion 14 is not formed by hanging the second electrode layer 122 in the electrode pad 13 as in the first embodiment described above. There is no need to leave the second electrode layer 122 to be formed. For this reason, in this embodiment, as described above, the piezoelectric layer 221 and the second electrode layer 222 are formed in the same shape in plan view in each of the device portion 22 and the electrode pad 23. .

  The piezoelectric device manufacturing method in this embodiment is basically the same as the piezoelectric device manufacturing method in the first embodiment shown in FIG. 2 except that the range of the resist mask for leaving the second electrode layer 122 is different as described above. The same. However, in this embodiment, it is not necessary to form the energization portion 14 with the second electrode layer 122 as in the seventh step (S17) of the first embodiment. In the present embodiment, in the process up to the removal of the resist mask 17, the piezoelectric layer 221 corresponding to the remaining second electrode layer 222 is simply removed. Thereafter, an energization process is performed in which a conductive adhesive is applied to form the energization portion 24 over the second electrode layer 222 in the electrode pad 23 and the first electrode layer 112 in the substrate 11. With the formation of the energization portion 24, the piezoelectric device 2 of FIG. 4 is completed.

  FIG. 5 compares the piezoelectric device of the first embodiment shown in FIG. 1 and the piezoelectric device of the second embodiment shown in FIG. 4 with the piezoelectric device without using the present invention. It is a figure which shows the comparative example for this.

  The comparative piezoelectric device 5 shown in FIG. 5 has the same configuration as the piezoelectric device 2 of the second embodiment shown in FIG. 4 except for the electrode pads 53. In FIG. 5, components equivalent to those of the piezoelectric device 2 of the second embodiment shown in FIG. 4 are denoted by the same reference numerals as those in FIG. 4. A duplicate description of elements is omitted.

  The piezoelectric device 5 of this comparative example also includes a substrate 11 in which a first electrode layer 112 made of platinum is formed on an oxide film 111a of a base 111 made of silicon. Then, on the first electrode layer 112 in the substrate 11, the device portion 22 having the piezoelectric layer 221 and the second electrode layer 222 formed in the same shape in plan view, and the electrode pad 53 are formed. ing.

  Here, in the piezoelectric device 5 of this comparative example, the single-layer electrode pad 53 is formed of gold on the first electrode layer 112 of the substrate 11. The electrode pad 53 obtains a bonding strength equivalent to that of the first wire BW1 by wire bonding to the second electrode layer 222 of the device portion 22 for bonding of the second wire BW2 to the first electrode layer 112 by wire bonding. Is for.

  In the manufacture of the piezoelectric device 5 of this comparative example, it is necessary to form the single-layer electrode pad 53 separately from the device portion 222, and the man-hour is increased accordingly.

  On the other hand, according to the piezoelectric devices 1 and 2 of the first embodiment, the modified example, and the second embodiment described above, the electrode pads 13, 23, and 131 are equivalent to the device portions 12 and 22. It has a laminated structure. Wire bonding to the electrode pads 13, 23, 131 is performed on the second electrode layers 122, 222 located in the upper layer, similarly to wire bonding to the device portions 12, 22. Since the second electrode layers 122 and 222 are energized to the first electrode layer 112 by the energizing portions 14, 24, and 141, wire bonding to the electrode pads 13, 23, and 131 is performed on the first electrode layer 112. It has almost the same electrical effect as wire bonding. At this time, since the second electrode layers 122 and 222 have a higher degree of freedom of the forming material than the first electrode layer 112 located below the piezoelectric layers 121 and 221, the second electrode layers 122 and 222 are made of gold to obtain good bonding strength. It is formed with. Since the electrode pads 13, 23, 131 have the same laminated structure as the device portions 12, 22, when manufacturing the piezoelectric devices 1, 2, in the manufacturing process of the device portions 12, 22, , 23 and 131 can be formed simultaneously to reduce the number of manufacturing steps. As described above, according to the piezoelectric devices 1 and 2 of the first embodiment, the modified example thereof, and the second embodiment, it is possible to manufacture while keeping good bonding strength for wire bonding while reducing the man-hours. it can.

  Here, in the piezoelectric device 1 of the first embodiment and its modification, the energization portions 14 and 141 extend until a part of the second electrode layer 122 in the electrode pads 13 and 131 reaches the first electrode layer 112. It has become. According to this, in the manufacturing process of the electrode pads 13 and 131, the current-carrying portions 14 and 141 can be formed at the same time, so that the device can be manufactured with further reduced man-hours.

  Further, in the piezoelectric device 2 of the second embodiment, the energization portion 24 is a conductive adhesive applied across the second electrode layer 222 in the electrode pad 23 and the first electrode layer 112 in the substrate 11. ing. According to this, since the energization part 24 can be formed by a simple method of applying a conductive adhesive, the piezoelectric device 2 can be manufactured while suppressing a decrease in yield.

  Further, when the above-described first embodiment, its modification, and the second embodiment are viewed with respect to the electrode pads 13, 23, 131 employed in the piezoelectric devices 1, 2, the following can be said. .

  That is, the electrode pads 13, 23, 131 of the first embodiment, the modified example, and the second embodiment have the piezoelectric layers 121, 221 sandwiched between the first electrode layers 112 and the second electrode layers 122, 222. Has a laminated structure. Therefore, wire bonding to the electrode pads 13, 23, 131 is performed on the second electrode layers 122, 222 located in the upper layer. Since the first electrode layer 112 is energized from the second electrode layers 122 and 222 through the energization portions 14 and 141, wire bonding to the electrode pads 13, 23, and 131 as described above is performed on the first electrode layer 112. It has almost the same electrical effect as wire bonding. At this time, since the second electrode layers 122 and 222 have a higher degree of freedom in forming material than the first electrode layer 112 located below the piezoelectric layer 121, the second electrode layers 122 and 222 are formed of gold in order to obtain good bonding strength. Has been. Since the electrode pads 13, 23, 131 have the above laminated structure, the electrode pads 13, 23, 131 are attached to the device portions 12, 22 having the same laminated structure as the electrode pads 13, 23, 131. When manufacturing the combined piezoelectric devices 1 and 2, it becomes possible to simultaneously form the electrode pads 13, 23, and 131 in the manufacturing process of the device portions 12 and 22 to reduce the number of steps. As described above, according to the electrode pads 13, 23, and 131 of the first embodiment, the modified example, and the second embodiment, it is possible to manufacture while keeping good bonding strength with respect to wire bonding and suppressing the man-hours. Can do.

  Further, the following can be said when the first embodiment, the modification thereof, and the second embodiment described above are viewed with respect to the piezoelectric device manufacturing method for manufacturing the piezoelectric devices 1 and 2.

  That is, according to the piezoelectric device manufacturing method of the first embodiment, the modified example, and the second embodiment, the electrode pads 13, 23, 131 in the manufactured piezoelectric devices 1, 2 are equivalent to the device portions 12, 22. It will have a structure. For this reason, wire bonding to the electrode pads 13, 23, 131 is performed on the second electrode layers 122, 222 located in the upper layer, similarly to wire bonding to the device portions 12, 22. Since the first electrode layer 112 is energized from the second electrode layers 122 and 222 through the energization portions 14 and 141, wire bonding to the electrode pads 13, 23, and 131 as described above is performed on the first electrode layer 112. It has almost the same electrical effect as wire bonding. At this time, since the second electrode layers 122 and 222 have a higher degree of freedom of forming material than the first electrode 112 positioned below the piezoelectric layers 121 and 221, the second electrode layers 122 and 222 are made of gold to obtain a good bonding strength. It is formed. Then, the electrode pads 13, 23 and 131 are formed simultaneously in the manufacturing process of the device portions 12 and 22 through the above-described removal process and energization process, so that the number of man-hours can be reduced. As described above, according to the piezoelectric device manufacturing method of the first embodiment, the modified example, and the second embodiment, it is possible to manufacture a device with a reduced man-hour while ensuring good bonding strength for wire bonding. it can.

  In the device manufacturing method of the first embodiment and its modification, the piezoelectric layer is such that the energization process hangs down until the electrode pads 13 and 131 partly reach the first electrode layer 112 of the second electrode layer 122. 121 is a process of removing. According to this, since the energization parts 14 and 141 can be simultaneously formed in the manufacturing process of the electrode pads 13 and 131, the device can be manufactured with further reduced man-hours.

  The following can also be said when the above-described first embodiment, its modifications, and the second embodiment are viewed with respect to the electrode pad manufacturing method employed in each piezoelectric device manufacturing method.

  That is, the electrode pad manufacturing method of the first embodiment, the modified example, and the second embodiment includes the following two steps. That is, a step of forming the second electrode layers 122 and 222 with the piezoelectric layers 121 and 221 sandwiched between the first electrode layer 112 and the first electrode layer 112 on the substrate 11, and the second electrode layers 122 and 222 and the first electrode layer 112, and a process of energizing 112. The former process corresponds to the first to fourth steps (S11 to S14) of FIG. 1, and the latter process corresponds to the fifth to seventh steps (S15 to S17) of FIG.

  According to this electrode pad manufacturing method, the manufactured electrode pads 13, 23 are stacked structures in which the second electrode layers 122, 222 are formed with the piezoelectric layers 121, 221 sandwiched between the first electrode layers 112. It will have. For this reason, the wire bonding to the manufactured electrode pads 13 and 23 is performed on the second electrode layers 122 and 222 located in the upper layer. Since the first electrode layer 112 is energized from the second electrode layers 122 and 222 through the energization portions 14 and 141, the wire bonding to the electrode pads 13 and 23 as described above is the wire bonding to the first electrode layer 112. It becomes almost the same effect electrically. At this time, since the second electrode layers 122 and 222 have a higher degree of freedom of forming material than the first electrode 112 positioned below the piezoelectric layers 121 and 221, the second electrode layers 122 and 222 are made of gold to obtain a good bonding strength. Forming. Since the electrode pads 13 and 23 have the above-described laminated structure, the piezoelectric devices 1 and 22 are formed by combining the electrode pads 13 and 23 with the device portions 12 and 22 having a laminated structure equivalent to the electrode pads 13 and 23. In the manufacturing process 2, the electrode pads 13, 23, and 131 can be simultaneously formed in the manufacturing process of the device portions 12 and 22 to reduce the number of steps. As described above, according to the electrode pad manufacturing method of the first embodiment, the modified example, and the second embodiment, it is possible to manufacture the electrode pad while suppressing the man-hour while ensuring the good bonding strength for the wire bonding.

  The present invention is not limited to the embodiments described above, and includes other configurations and the like that can achieve the object of the present invention. The following modifications and the like are also included in the present invention.

  For example, in the first embodiment, the modified example, and the second embodiment described above, as an example of the device according to the present invention, the piezoelectric layer 121, between the first electrode layer 112 and the second electrode layers 122, 222, Piezoelectric devices 1 and 2 having device portions 12 and 22 sandwiching 221 are illustrated. However, the device referred to in the present invention is not limited to these, as long as it includes a device portion in which a second electrode layer is formed with an electrically driven element layer interposed between the device and the first electrode layer. The element layer sandwiched between the two electrode layers can be arbitrarily set.

  In the first embodiment, the modified example, and the second embodiment described above, examples of the device, the piezoelectric device, and the electrode pad according to the present invention are shown in FIGS. 1, 3, and 4. Shaped piezoelectric devices 1 and 2 and electrode pads 13 and 23 are illustrated. However, the devices, piezoelectric devices, and electrode pads referred to in the present invention are not limited to these, and the specific shapes thereof are not limited.

DESCRIPTION OF SYMBOLS 1, 2 Piezoelectric device 11 Board | substrate 12,22 Device part 13,23,131 Electrode pad 14,24,141 Current supply part 15 Layer structure member 16,17,171 Resist mask 111 Base body 111a Oxide film 112 1st electrode layer 121,221 Piezoelectric layer 122, 222 Second electrode layer BW1 First wire BW2 Second wire

Claims (5)

A predetermined device portion and an electrode pad spaced apart from the device portion are left from the layer structure member in which the second electrode layer is provided with the electrically driven element layer sandwiched between the first electrode layer and the first electrode layer. A removing step of removing the second electrode layer;
An energization step of energizing the first electrode layer and the second electrode layer in the electrode pad;
A device manufacturing method comprising:   2. The device according to claim 1, wherein the energizing step is a step of removing the element layer so that a part of the second electrode layer hangs down to reach the first electrode layer with respect to the electrode pad. Device manufacturing method. The energization process includes
Removing the element layer corresponding to the second electrode layer removed in the removing step;
Applying a conductive adhesive across the second electrode layer and the first electrode layer in the electrode pad;
The device manufacturing method according to claim 1, wherein: A layer in which a second electrode layer is provided on a substrate having a plate-like substrate and a first electrode layer formed on the surface of the substrate with a piezoelectric layer interposed therebetween. A layer structure forming step of forming a structural member;
A removal step of removing the second electrode layer from the layer structure member leaving a predetermined device portion and an electrode pad spaced apart from the device portion;
An energization step of energizing the second electrode layer in the electrode pad and the first electrode layer in the substrate;
A method for manufacturing a piezoelectric device, comprising: Forming a second electrode layer with an electrically driven element layer sandwiched between the first electrode layer on the substrate;
Energizing the second electrode layer and the first electrode layer;
An electrode pad manufacturing method comprising:

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