PIEZOELECTRIC DEVICE

• US 20200136586A1
• Filed: 08/27/2019
• Published: 04/30/2020
• Est. Priority Date: 10/26/2018
• Status: Active Grant

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Corporation
• Inventors: TERAUCHI, Yuuki, ANDOU, Motoharu, YOKOO, Yoshiaki
• Granted Patent: US 11,251,768 B2
• Time in Patent Office: Days
• CPC Class Codes: H03H 9/02102 of temperature influence cutting angles H03H9/02015
• CPC Class Codes: H03H 9/0509 consisting of adhesive elements
• CPC Class Codes: H03H 9/0552 the device and the other elements being mounted on opposite sides of a common substrate
• CPC Class Codes: H03H 9/1021 the BAW device being of the cantilever type
• CPC Class Codes: H03H 9/19 consisting of quartz

Abstract

A piezoelectric device includes a piezoelectric element, a package, a temperature sensitive component and a conductive adhesive. The package includes a base body and a connection conductor. The base body has electric insulation and configures a space. The space is sealed and holds the piezoelectric element. The connection conductor is located on a predetermined surface of the base body. The predetermined surface is on an outer side relative to the space. The temperature sensitive component includes apart terminal and converts temperature to an electrical signal. The conductive adhesive is configured by a thermosetting resin containing a conductive filler and is bonded to the connection conductor and the part terminal.

Claims

1. A piezoelectric device comprising

a piezoelectric element,

a package which comprises

a base body having electric insulation and configuring a space which is sealed and holds the piezoelectric element and

a connection conductor located on a predetermined surface of the base body, the predetermined surface being on an outer side relative to the space,

a temperature sensitive component which comprises a part terminal and converts temperature to an electrical signal, and

a conductive adhesive which is configured by a thermosetting resin containing a conductive filler and is bonded to the connection conductor and the part terminal.

2. The piezoelectric device according to claim 1, wherein:

in a plan view of the predetermined surface, the part terminal and the connection conductor are separated from each other,

the conductive adhesive comprises

an element corresponding part which is bonded to the part terminal and

a wiring part which connects the element corresponding part and the connection conductor, and

the element corresponding part and the wiring part directly contact the predetermined surface having electric insulation.

3. The piezoelectric device according to claim 1, further comprising an underfill filled between the predetermined surface and the temperature sensitive component.

4. The piezoelectric device according to claim 1, further comprising a circuit board, wherein

the circuit board comprises

a first surface facing the predetermined surface,

a second surface on a back of the first surface,

an opening which penetrates from the first surface to the second surface and holds the temperature sensitive component,

a mounting pad which is located on the first surface, faces the connection conductor, and is bonded to it through a conductive bonding material, and

an external terminal which are located on the second surface and is electrically connected with the mounting pad.

5. The piezoelectric device according to claim 2, further comprising a circuit board, wherein

the circuit board comprises

a first surface facing the predetermined surface,

a second surface on a back of the first surface,

an opening which penetrates from the first surface to the second surface and holds the temperature sensitive component,

a mounting pad which is located on the first surface, faces the connection conductor, and is bonded to it through a conductive bonding material, and

an external terminal which are located on the second surface and is electrically connected with the mounting pad,

the temperature sensitive component comprises a pair of the part terminals,

the package comprises a pair of the connection conductors,

the piezoelectric device comprises a pair of the conductive adhesives which individually connect the pair of part terminals and the pair of connection conductors, and

the pair of conductive adhesives comprise mutually point symmetrical shapes relative to a geometric center of the opening in a region where they overlap the opening.

6. The piezoelectric device according to claim 4, wherein

the bonding material is made of metal and is bonded to the mounting pad between the mounting pad and the connection conductor, and

the conductive adhesive is interposed between at least a part of the connection conductor and the bonding material and is bonded to the two.

7. The piezoelectric device according to claim 4, wherein

the bonding material is bonded to the mounting pad between the mounting pad and the connection conductor,

the conductive adhesive comprises a first part which follow along at least a portion of a edge part of the connection conductor in a plan view of the predetermined surface, and

the bonding material is bonded to the connection conductor at a position being on an inner side of the connection conductor relative to the first part in a plan view of the predetermined surface.

8. The piezoelectric device according to claim 7, wherein

the package comprises a plurality of mounting terminals including the connection conductor on the predetermined surface, and

the first part follow along at least a part of a portion of an outer edge of the connection conductor, the portion of the outer edge being on a side of the other mounting terminal other than the connection conductor.

9. The piezoelectric device according to claim 8, wherein, in each of all of the mounting terminals, either of the first part of the conductive adhesive which is bonded to the part terminal or an other conductive adhesive which is not bonded to the part terminal is located following along at least a part of a portion of an outer edge of the mounting terminal, the portion of the outer edge being on a side of the other mounting terminal.