JP5804762B2 - Piezoelectric device - Google Patents

Description

The present invention relates to a piezoelectric device having a piezoelectric element such as a piezoelectric vibration element.

Conventionally, piezoelectric devices have been used in electronic devices such as portable communication devices. As shown in FIGS. 4 and 5, such a conventional piezoelectric device 200 mainly includes an element mounting member 210, an integrated circuit element 220, a piezoelectric element 230, and a lid member 240 as an example.

As shown in FIG. 4, the element mounting member 210 is mainly configured by a substrate portion 211 and two wall portions 212 and 213. In the element mounting member 210, a wall portion 212 is provided on one main surface of the substrate portion 211 to form a recessed space K1, and a wall portion 213 is provided on the other main surface of the substrate portion 211, so that the recessed space K2 is formed. It is formed. As shown in FIG. 4, a pair of excitations electrically connected to the piezoelectric element mounting pad 215 via a conductive adhesive 232 are formed on one main surface of the substrate portion 211 exposed in the recessed space K1. A piezoelectric element 230 having electrodes for the front and back main surfaces is accommodated. The top surface of the wall portion 212 of the element mounting member 210 surrounding the piezoelectric element 230 is covered with a metal lid member 240 and joined. Thereby, the recessed space K1 is hermetically sealed.

  Also, as shown in FIG. 5, a plurality of integrated circuit element mounting pads 218 and a pair of piezoelectric element measurement pads 214 are provided on the other main surface of the substrate portion 211 exposed in the recessed space K2. . On the plurality of integrated circuit element mounting pads 218, an integrated circuit element 220 connected to the substrate portion 211 via a conductive bonding material 222 such as solder is mounted. For example, as shown in FIG. 4, the piezoelectric device 200 is generally filled with a filling member 250 between the other main surface of the substrate portion 211 and the circuit formation surface of the integrated circuit element 220 (for example, Patent Document 1).

  Here, since the integrated circuit element 220 is attached to the element mounting member 210 with the circuit formation surface facing the substrate portion 211, the filling member 250 is filled between the integrated circuit element 220 and the element mounting member 210. Thus, the circuit forming surface is protected. The piezoelectric device 200 is mounted on an external wiring board such as a motherboard, and the external connection terminals 216 provided on the lower surface of the element mounting member 210 are solder-bonded to the wiring of the external wiring board. Connected on the external wiring board.

The element mounting member 210 is usually made of a ceramic material, and a wiring conductor is formed inside or on the surface of the element mounting member 210. The element mounting member 210 is manufactured by employing a conventionally known ceramic green sheet lamination method or the like.

JP 2005-6171 A

However, when the integrated circuit element 220 is disposed in the recessed space K2 of the element mounting member 210, the conventional piezoelectric device 200 described above is integrated with the wall portion 213 of the element mounting member 210 as the piezoelectric device 200 is downsized. The gap between the circuit elements 220 is narrowed, and the tip of the filling nozzle for filling the filling member 250 cannot be inserted into the gap. As a result, in the conventional piezoelectric device 200, the filling member 250 does not sufficiently enter between the integrated circuit element 220 and the substrate portion 211 of the element mounting member 210, and the opposite surface (lower surface) of the circuit formation surface of the integrated circuit element 220. The filling member 250 has a drawback that it adheres.

Accordingly, the present invention provides a piezoelectric device that solves the above-described problems and that has a sufficient filling member between the integrated circuit element and the substrate portion of the element mounting member, and has improved reliability. Let it be an issue.

A piezoelectric device according to one aspect of the present invention includes:
An element mounting member having a substrate portion and two wall portions provided on both main surfaces of the substrate portion;
A piezoelectric element mounted on one main surface of the substrate portion of the element mounting member;
An integrated circuit element provided on the other main surface of the substrate portion;
Equipped with a filling member that is provided between the other main surface and the integrated circuit element of the substrate section,
The element mounting member has a convex portion protruding in the direction of the integrated circuit element from the wall portion provided on the other main surface of the substrate portion ,
The height of the convex portion from the other main surface of the substrate portion is
Higher than the height from the other main surface of the substrate portion of the integrated circuit element;
The wall portion provided on the other main surface of the substrate portion is formed to be lower than a height from the other main surface of the substrate portion .

Thus, a piezoelectric device according to one aspect of the invention is
An element mounting member having a substrate portion and two wall portions provided on both main surfaces of the substrate portion;
A piezoelectric element mounted on one main surface of the substrate portion of the element mounting member;
An integrated circuit element provided on the other main surface of the substrate portion;
Equipped with a filling member that is provided between the other main surface and the integrated circuit element of the substrate section,
The element mounting member has a convex portion protruding in the direction of the integrated circuit element from the wall portion provided on the other main surface of the substrate portion ,
The height of the convex portion from the other main surface of the substrate portion is
Higher than the height from the other main surface of the substrate portion of the integrated circuit element;
The wall portion provided on the other main surface of the substrate portion is formed lower than the height of the substrate portion from the other main surface .
As a result, the piezoelectric device of the present invention has a filling member not attached to the opposite surface (lower surface) of the circuit formation surface of the integrated circuit element,
The capillarity of the filling member between the integrated circuit element and the convex portion provided between the wall portion,
The filling member can be allowed to flow between the integrated circuit element and the other main surface of the substrate portion.
Therefore, in the piezoelectric device according to one aspect of the present invention, the filling member is sufficiently provided between the integrated circuit element and the other main surface of the substrate portion of the element mounting member,
Reliability can be improved.

It is sectional drawing which showed an example of the piezoelectric device which concerns on embodiment of this invention. It is a top view which shows the other main surface of the board | substrate part of the element mounting member which comprises the piezoelectric device of this invention. It is the fragmentary sectional view showing an example of the piezoelectric device concerning the embodiment of the present invention. It is sectional drawing which showed an example of the conventional piezoelectric device. It is a top view which shows the other main surface of the board | substrate part of the element mounting member which comprises the conventional piezoelectric device.

  Hereinafter, a piezoelectric device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Note that each component is exaggerated for easy understanding of the state. A sectional view showing an example of the piezoelectric device of the present invention is shown in FIG. Moreover, the top view which shows the other main surface of the board | substrate part of the element mounting member which comprises the piezoelectric device of this invention is shown in FIG. Moreover, the fragmentary sectional view which shows an example of the piezoelectric device of this invention is shown in FIG. As shown in FIG. 1, the piezoelectric device 100 of the present invention mainly includes an element mounting member 110, an integrated circuit element 120, a piezoelectric element 130, and a lid member 140.

  As shown in FIG. 1, the element mounting member 110 mainly includes a substrate part 111 and two wall parts 112 and 113. In this element mounting member 110, a wall portion 112 is provided on one main surface of the substrate portion 111 to form a recessed space K1, and a wall portion 113 is provided on the other main surface of the substrate portion 111 to provide a recessed space K2. It is formed. The element mounting member 110 is usually formed of a ceramic material, and a wiring conductor is formed inside or on the surface thereof, and is manufactured by a ceramic green sheet laminating method or the like.

  As shown in FIG. 1, a pair of excitations that are electrically connected to the piezoelectric element mounting pad 115 via a conductive adhesive 132 are formed on one main surface of the substrate 111 exposed in the recessed space K1. A piezoelectric element 130 having main electrodes (not shown) on the front and back main surfaces is accommodated. The top surface of the wall portion 112 of the element mounting member 110 surrounding the piezoelectric element 130 is covered with and bonded to a metal lid member 140. Thereby, the recessed space K1 is hermetically sealed.

  As shown in FIGS. 1 and 2, a plurality of integrated circuit element mounting pads 118 and a pair of piezoelectric element measurement pads 114 are provided on the other main surface of the substrate portion 111 exposed in the recessed space K2. It has been. On the plurality of integrated circuit element mounting pads 118, the integrated circuit element 120 connected via a conductive bonding material 122 such as solder is mounted.

As shown in FIGS. 1 and 2, in the piezoelectric device 100 of the present invention, a convex portion 117 protruding from the wall portion 113 toward the integrated circuit element 120 is formed between the integrated circuit element 120 and the wall portion 113. ing. An external connection terminal 116 is provided on the end surface of the wall 113. The external connection terminal 116 is a terminal for connecting the piezoelectric device 100 to a wiring of an external wiring board such as a mother board. For connection between the external connection terminal 116 and the external wiring board, for example, a conductive bonding material such as solder is used. The piezoelectric device 100 is filled with a filling member 150 between the other main surface of the substrate portion 111 and the circuit forming surface of the integrated circuit element 120.

  The integrated circuit element 120 is attached to the element mounting member 110 with the circuit formation surface facing the surface side of the element mounting member 110. Therefore, a filling member 150 is filled between the integrated circuit element 120 and the element mounting member 110 to protect the circuit formation surface. In addition, the integrated circuit element 120 is formed on one main surface of a silicon wafer obtained by slicing a single crystal silicon ingot to a predetermined thickness, for example, an electronic circuit such as an oscillation circuit, an electrode pad, or the like by a conventionally well-known semiconductor manufacturing technique. It is manufactured by forming.

  Further, as shown in FIG. 1, the convex portion 117 protruding from the wall portion 112 of the piezoelectric device 100 of the present invention toward the integrated circuit element 120 has a height from the main surface of the substrate portion 111 so that the integrated circuit element has a height. The height of 120 from the main surface of the substrate portion 111 is higher than the height of the wall 113 from the main surface of the substrate portion 111. That is, as shown in FIG. 3, when the height from the main surface of the substrate portion 111 to the wall portion 113 is KB and the height from the main surface of the substrate portion 111 to the integrated circuit element 120 is IC, the convex portion 117. The height H is higher than the height IC of the integrated circuit element 120 and is lower than the height KB of the wall 113. Further, the convex portion 117 is formed of a ceramic material similarly to the element mounting member 110, and is manufactured by a ceramic green sheet laminating method or the like.

The filling member 150 is made of an epoxy resin or the like, and is filled between the integrated circuit element 120 and the element mounting member 110 and covers the circuit formation surface (upper surface) of the integrated circuit element 120 as shown in FIG. Yes. Thereby, it is possible to effectively prevent the circuit formation surface (upper surface) of the integrated circuit element 120 from being corroded by moisture in the atmosphere by the filling member 150. Further, in the piezoelectric device 100 of the present invention, the attachment strength of the integrated circuit element 120 to the element mounting member 110 that houses the integrated circuit element 120 is improved.

A filling method of the filling member 150 of the piezoelectric device 100 will be described. FIG. 3 is a partial sectional view showing an example of the piezoelectric device 100 according to the embodiment of the present invention. For example, the piezoelectric device 100 of the present invention has outer dimensions of 2520 type (2.5 * 2.0 mm) or less and a height of about 1.0 mm. Further, as shown in FIG. 3, the filling nozzle 160 for filling the filling member 150 has a nozzle diameter D1 of about 0.45 mm in diameter and a nozzle diameter D2 of the nozzle tip portion of about 0.23 mm.

  In addition, the 2520 type (2.5 * 2.0 mm) piezoelectric device 100 has a chip size of the integrated circuit element 120 of about 1.4 * 1.2 mm and a thickness of the wall 113 of about 0.2 to 0.3 mm. Become. From the above dimensions, in the 2520 type piezoelectric device 100, the distance between the integrated circuit element 120 and the wall 113 is about 0.1 to 0.2 mm, and the tip D2 (0.23 mm) of the filling nozzle 160 is connected to the integrated circuit. It becomes impossible to put between the element 120 and the wall 113.

Therefore, in the small piezoelectric device 100 of the 2520 type (2.5 * 2.0 mm) or less, the filling member 150 is partially filled from the upper surface of the integrated circuit element 120. At that time, as shown in FIG. 3, the piezoelectric device 100 of the present invention is provided with a convex portion 117 protruding from the wall 113 toward the integrated circuit element 120 between the integrated circuit element 120 and the wall 113. Thus, the interval between the integrated circuit element 120 and the convex portion 117 is narrow. Accordingly, in the piezoelectric device 100 of the present invention, the filling member 150 is transmitted from the upper surface to the side surface of the convex portion 117 due to a capillary phenomenon, and enters between the integrated circuit element 120 and the element mounting member 110. Therefore, the piezoelectric device 100 of the present invention can easily and reliably fill the filling member 150. Here, in the piezoelectric device 100 of the present invention, the width of the convex portion 117 protruding in the direction of the integrated circuit element 120 from the wall portion 113 is about 0.05 to 0.1 mm, and the integrated circuit element 120 and the convex portion 117 The interval W is about 0.05 to 0.1 mm.

Thus, in the conventional piezoelectric device 200, the tip D2 (0.23 mm) of the filling nozzle 160 does not enter between the integrated circuit element 220 and the wall portion 213, and it takes time to fill the filling member 250. . On the other hand, the piezoelectric device 100 according to the embodiment of the present invention can easily fill the filling member 150 due to the capillary phenomenon of the filling member 150 due to a narrow interval between the integrated circuit element 120 and the convex portion 117. it can.

  In the piezoelectric device 100 of the present invention, as shown in FIGS. 1 and 3, the convex portion 117 is formed to be higher than the height from the main surface of the substrate portion 111 of the integrated circuit element 120. Thereby, in the piezoelectric device 100 of the present invention, the filling member 150 adheres to the surface opposite to the circuit formation surface (upper surface) of the integrated circuit element 120, that is, the outer surface (lower surface) of the integrated circuit element 120. Can be prevented. That is, in the piezoelectric device 100 of the present invention, when the filling member 150 is injected from the outer surface (lower surface) of the integrated circuit element 120, the filling member 150 has the convex portion 117 before touching the outer surface of the integrated circuit element 120. The top surface is touched and flows from the top surface to the side surface of the convex portion 117 and enters between the integrated circuit element 120 and the element mounting member 110, and adhesion of the filling member 150 to the outer surface of the integrated circuit element 120 can be prevented. .

Further, as shown in FIG. 2, the piezoelectric device 100 of the present invention includes an external connection terminal 116 on the end surface of the wall portion 113, and the convex portion 117 is connected to the external connection terminal 116 of the end surface of the wall portion 113. It is provided corresponding to the area not provided. That is, as shown in FIG. 2, assuming that the region where the external connection terminal 116 is not provided on the end surface of the wall 113 is T, and the region where the convex 117 is provided is L, the region L of the convex 117 is provided. Is provided in a range shorter than the region T where the external connection terminal 116 is not provided (L <T). Thereby, the piezoelectric device 100 of this invention can reduce possibility that the filling member 150 will adhere to the external connection terminal 116. FIG.

In the piezoelectric device of the present invention, as shown in FIG. 3, the height H of the convex portion 117 from the main surface of the substrate portion 111 is the height IC from the main surface of the substrate portion 111 of the integrated circuit element 120. Higher than the height KB from the main surface of the substrate portion 111 of the wall portion 113. Thereby, since the filling member 150 can be prevented from flowing from the upper surface of the convex portion 117 to the wall portion 113, the piezoelectric device 100 of the present invention may adhere to the end surface of the wall portion 113. Thus, it is possible to prevent a connection failure between the external connection terminal 116 and the external wiring board due to a conductive bonding material such as solder.

Therefore, the piezoelectric device 100 of the present invention is improved to the external wiring board for connecting and mounting various components performed thereafter while improving the reliability between the integrated circuit element 120 and the substrate portion 111 of the element mounting member 110. Therefore, it is possible to prevent connection failures of various devices.

In addition to the above-described embodiments, various changes and improvements can be made without departing from the scope of the present invention. For example, FIG. 1 shows the structure of the element mounting member 110 in which the integrated circuit element 120 and the piezoelectric element 130 and the wall portions 112 and 113 are formed on the upper and lower surfaces of the substrate portion 111. And the piezoelectric element 130 are formed on an element mounting member 110 composed of separate substrate portions 111 and one wall portion 112, and the element mounting members are stacked one above the other, or the wall portion 113 is a structure having only the lower surface, The sealing lid may be box-shaped. In the embodiment, the lower wall portion 113 has a frame shape. However, for example, a clog-like wall portion 113 in which the wall portions 123 are arranged in parallel may be used.

DESCRIPTION OF SYMBOLS 100 ... Piezoelectric device 110 ... Element mounting member 111 ... Substrate part 112 ... Wall part 113 ... Wall part 114 ... Piezoelectric element measurement pad 115 ... Piezoelectric element mounting pad 116- ..External connection terminals 117... Projection 118... Integrated circuit element mounting pad 120... Integrated circuit element 122... Conductive bonding material 130. ... Lid member 150 ... Filling member 160 ... Filling nozzle K1 ... Recessed space K2 ... Recessed space

Claims (1)

An element mounting member having a substrate portion and two wall portions provided on both main surfaces of the substrate portion;
A piezoelectric element mounted on one main surface of the substrate portion of the element mounting member;
An integrated circuit element provided on the other main surface of the substrate portion;
A filling member provided between the other main surface of the substrate portion and the integrated circuit element ;
With
The element mounting member has a convex portion protruding in the direction of the integrated circuit element from the wall portion provided on the other main surface of the substrate portion ,
The height of the convex portion from the other main surface of the substrate portion is higher than the height from the other main surface of the substrate portion of the integrated circuit element, and is provided on the other main surface of the substrate portion. The piezoelectric device , wherein the wall portion is formed to be lower than a height from the other main surface of the substrate portion .

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