JP2008219835A - Piezoelectric device manufacturing method, piezoelectric device, and electronic apparatus - Google Patents

Abstract

A method for manufacturing a piezoelectric device, a piezoelectric device, and an electronic apparatus that reliably connect a piezoelectric vibrator and a connection member are provided.
A piezoelectric device includes a substrate. An electronic component 24 is disposed on one surface of the substrate 12 and is electrically connected to the external terminal 20 provided on the other surface of the substrate 12. Further, a connection member 28 is provided on one surface of the substrate 12 and is electrically connected to the electronic component 24 via the conduction means 26. A resin mold 30 is provided on one surface of the substrate 12. The resin mold 30 covers the electronic component 24 and the conduction means 26 and covers the lower end side and the center portion of the connection member 28. For this reason, the upper end side of the connection member 28 protrudes from the upper surface of the resin mold 30. The piezoelectric vibrator 40 is disposed on the resin mold 30. At this time, since the upper end side of the connection member 28 protrudes from the resin mold 30, the connection member 28 can be electrically connected to the vibrator terminal 52 of the piezoelectric vibrator 40.
[Selection] Figure 1

Description

  The present invention relates to a piezoelectric device in which a piezoelectric vibrator is disposed above and integrated with an electronic component, a method for manufacturing the same, and an electronic apparatus including the piezoelectric device.

Some piezoelectric devices have a piezoelectric vibrator and an oscillation circuit arranged in a two-story structure. There exists patent document 1 in what disclosed about such a piezoelectric device. The piezoelectric oscillator disclosed in Patent Document 1 includes an integrated circuit element, a piezoelectric vibrator, and an oscillation circuit substrate. The integrated circuit element is disposed on the oscillation circuit substrate together with the spherical solder, and is electrically connected to the spherical solder through the wiring pattern. This integrated circuit element is covered with a sealing material. In addition, the outer part of the spherical solder is covered with a non-conductive resin or the like, or is covered with a sealing material. The piezoelectric vibrator is fixed on the spherical solder, and is electrically connected to the integrated circuit element through the solder.
Japanese Patent Laying-Open No. 2004-180012 (pages 9-16, FIGS. 2 and 12)

  Some of the piezoelectric oscillators described above have a configuration in which a piezoelectric vibrator is mounted on an oscillation circuit substrate via a spherical solder, and then the oscillation circuit element and the spherical solder are covered with a sealing material or the like. The piezoelectric oscillator having such a configuration can seal the oscillation circuit element and the spherical solder in one filling operation of the sealing material. Before this sealing process, the piezoelectric vibrator is turned into the spherical solder. Since the connecting step is performed, problems such as the wire being eroded by the solder applied to the spherical solder and the wiring pattern on the oscillation circuit board being short-circuited occur.

Further, since the piezoelectric oscillator described above is filled with a sealing material using a dispenser, a filling operation must be performed for each integrated circuit element. This leads to a long lead time. Further, this piezoelectric oscillator has a configuration in which spherical solder is protected by a resin. In this configuration, a filling work of a sealing material and a resin coating work are required. Therefore, a total of two resin sealing steps are required for each product.
It is an object of the present invention to provide a method for manufacturing a piezoelectric device, a piezoelectric device, and an electronic apparatus that reliably connect a piezoelectric vibrator and a connection member.

  The method for manufacturing a piezoelectric device according to the present invention includes a step of arranging an electronic component and a connection member for each of a plurality of device formation regions on a sheet substrate, a resin mold formed on the sheet substrate to cover the electronic component, and a connection A step of forming the upper surface of the resin mold at a position lower than the top of the member, and a step of fixing the piezoelectric vibrator on the resin mold and conducting the connection member and the piezoelectric vibrator protruding from the upper surface of the resin mold. It is characterized by performing in order.

  Electronic parts and the like disposed in the resin mold are not exposed to the outside of the resin mold. For this reason, even if the piezoelectric vibrator is arranged on the resin mold, the portion where the piezoelectric vibrator and the connection member are electrically connected to the electronic component or the like passes through the wiring pattern provided on one surface of the sheet substrate. Without being short-circuited. In addition, since the resin mold is formed on the sheet substrate having a plurality of device forming regions, a plurality of device forming regions including the conduction means and the electronic components can be collectively molded. For this reason, lead time can be shortened.

  The method for manufacturing a piezoelectric device according to the present invention includes joining a conduction means to an electronic component, conducting the electronic component and the connection member via the conduction means, and selecting the highest part of the conduction means and the top surface of the electronic component. The upper surface of the resin mold is formed between the higher one of these and the top of the connecting member. Electronic components and conduction means can be arranged in the resin mold, and they are not exposed to the outside of the resin mold. On the other hand, the upper end side of the connection member protrudes outside the resin mold. As a result, even if the piezoelectric vibrator is disposed on the resin mold, the wiring pattern provided on one surface of the sheet substrate is connected to the portion where the piezoelectric vibrator and the connection member are electrically connected to the electronic component or the conductive means. Short-circuiting can be prevented without intervening.

  In addition, the piezoelectric device manufacturing method according to the present invention is characterized in that after a sheet substrate on which a resin mold is formed is separated into individual device forming regions, a piezoelectric vibrator is fixed to the upper surface of the resin mold. This can prevent the side surfaces of the piezoelectric vibrator from being cut when the sheet substrate is separated.

  In addition, the piezoelectric device according to the present invention has an electronic component disposed on one surface of the substrate, is electrically connected to an external terminal provided on the other surface of the substrate, and the connection member that is electrically connected to the electronic component is connected to one surface of the substrate. The resin member is provided around the central portion and the lower end side of the connecting member while the upper end side of the connecting member is exposed to the outside, the resin mold is provided around the electronic component, and the piezoelectric vibrator is provided on the resin mold. It is characterized in that the piezoelectric vibrator is bonded to the upper end side of the connecting member protruding from the upper surface of the resin mold. Electronic parts and the like disposed in the resin mold are not exposed to the outside of the resin mold. For this reason, even if the piezoelectric vibrator is arranged on the resin mold, the portion where the piezoelectric vibrator and the connection member are conducted is not connected to the wiring pattern provided on one surface of the sheet substrate, and the electronic component. And short-circuiting with wires can be prevented.

  The electronic component described above is electrically connected to the connection member and the external terminal through the wire, and the upper surface of the resin mold is located higher than the highest point of the wire loop. Electronic components and wires can be arranged in the resin mold, and they are not exposed to the outside of the resin mold. As a result, even if the piezoelectric vibrator is disposed on the resin mold, the wiring pattern provided on one surface of the sheet substrate is connected to the portion where the piezoelectric vibrator and the connection member are electrically connected to the electronic component or the conductive means. Short-circuiting can be prevented without intervening.

  An electronic apparatus according to the present invention is characterized by mounting the above-described piezoelectric device. The piezoelectric device has high reliability because there is no poor conduction between the connecting member and the piezoelectric vibrator. For this reason, the reliability of an electronic device can also be improved.

  Embodiments of a piezoelectric device manufacturing method, a piezoelectric device, and an electronic apparatus according to the present invention will be described below. First, the first embodiment will be described. FIG. 1 is a cross-sectional view of a piezoelectric device. The piezoelectric device 10 has a substrate 12, and an external terminal 20 is provided on the other surface of the substrate 12. An electronic component 24 is fixed to one surface of the substrate 12. A plurality of bonding electrodes 14 are provided on one surface of the substrate 12, and the bonding electrodes 14 are electrically connected to the electronic component 24 through conductive means 26 bonded thereon. For example, the conduction means 26 may be a wire when the electronic component 24 is mounted face-up, and may be a flip chip when the electronic component 24 is mounted face-down. In this embodiment, a wire is used as the conduction means 26. Then, the active surface of the electronic component 24, that is, the surface provided with the electronic component side pad (not shown) to which the wire is bonded is directed to the opposite side of the substrate 12, and the electronic component 24 is mounted face up on the substrate 12. The wire is bonded to the electronic component side pad and the bonding electrode 14.

  A part of the plurality of bonding electrodes 14 is electrically connected to a connection member arrangement electrode 16 provided on one surface of the substrate 12 through a wiring pattern (not shown). The other bonding electrode 14 is electrically connected to the external terminal 20 through a conductive portion 18 provided through the substrate 12. The conductive portion 18 may be a via hole, for example. Accordingly, the electronic component 24 is electrically connected to the connection member arranging electrode 16 and is electrically connected to the external terminal 20. A connection member 28 is provided on the connection member arrangement electrode 16. The connection member 28 has conductivity, and may be a metal ball, for example. The connecting member 28 may be a core formed by copper balls or the like and solder-plated.

  As described above, the resin mold 30 is provided on one surface of the substrate 12 on which the electronic component 24, the connection member 28, the conduction means 26, and the like are disposed. The resin mold 30 covers the center portion and the lower end side of the connection member 28 while exposing the upper end side (top side) of the connection member 28 to the outside. The resin mold 30 covers the electronic component 24 and the conduction means 26. When the conducting means 26 is a wire, the upper surface of the resin mold 30 is at a position higher than the highest point of the loop. That is, the upper surface of the resin mold 30 is at a position higher than the highest point of the loop of the wire and lower than the upper end (top) which is the highest position of the connecting member 28. When the conduction means 26 is a flip chip, the upper surface of the resin mold 30 is located higher than the upper surface of the electronic component 24. That is, the upper surface of the resin mold 30 is at a position higher than the upper surface of the electronic component 24 and lower than the upper end of the connection member 28.

  A piezoelectric vibrator 40 is provided on such a resin mold 30. The piezoelectric vibrator 40 includes a package 42 and a piezoelectric vibrating piece 56. The package 42 includes a package base 44 having a recess 46 and a lid 48 joined to the upper surface of the package base 44. The recessed portion 46 is hermetically sealed by the lid 48. The package base 44 includes a mount electrode 50 on the bottom surface (the bottom surface of the recessed portion 46) and a transducer terminal 52 on the back surface, and the mount electrode 50 and the transducer terminal 52 are electrically connected to each other. Yes. A conductive adhesive 54 is provided on the mount electrode 50, and the piezoelectric vibrating piece 56 is electrically and mechanically connected by the conductive adhesive 54. The piezoelectric vibrating piece 56 may be a piezoelectric vibrating piece using an AT-cut piezoelectric element plate, a tuning fork type piezoelectric vibrating piece, a surface acoustic wave element piece, or the like. Since the conductive bonding material 32 is provided on the upper end side of the connection member 28 protruding from the upper surface of the resin mold 30, the piezoelectric vibrator 40 is disposed on the resin mold 30, and the conductive bonding material 32 is attached. Thus, the transducer terminal 52 and the connection member 28 are electrically connected. Thus, the piezoelectric device 10 has a configuration in which the electronic component 24 and the piezoelectric vibrator 40 are arranged in the stacking direction.

  The manufacturing method of such a piezoelectric device 10 is as follows. FIG. 2 is an explanatory diagram of the manufacturing process of the piezoelectric device. First, as shown in FIG. 2A, an insulating sheet substrate 12a is prepared. The sheet substrate 12a has a plurality of device formation regions A. On one surface of the sheet substrate 12a, the connection member placement electrode 16, the bonding electrode 14, the wiring pattern, and the like are provided for each device formation region A. Further, an external terminal 20 is provided for each device formation region A on the other surface of the sheet substrate 12a. The sheet substrate 12a becomes the substrate 12 when it is cut for each device formation region A in order to separate the piezoelectric device 10 into individual pieces.

The connection member 28 and the electronic component 24 are disposed on one surface of the sheet substrate 12a. The connection member 28 is arranged on the connection member arrangement electrode 16. The electronic component 24 is fixed to a predetermined position on the sheet substrate 12a. The electronic component 24 may be provided with a circuit (oscillation circuit) that supplies an electric signal to the piezoelectric vibrator 40 to oscillate and amplify it, and is an integrated circuit (IC) chip. The electronic component 24 may include a voltage control circuit that changes the oscillation frequency according to a control voltage input from the outside, and a temperature compensation circuit that corrects the oscillation frequency according to the ambient temperature of the piezoelectric vibrating piece 56. In this embodiment, since the wire is used as the conduction means 26, the wire is bonded to the electronic component 24 and the bonding electrode 14 by wire bonding, and these are electrically connected.

  Thereafter, the resin mold 30 is formed on one surface of the sheet substrate 12a. This can be done by printing. Through this mold forming step, the electronic component 24 and the conduction means 26 are covered with the resin mold 30, and the lower end side and the central portion of the connection member 28 are covered with the resin mold 30. Thereby, the upper end side of the connection member 28 protrudes from the upper surface of the resin mold 30.

  Thereafter, the sheet substrate 12a is separated into pieces for each device formation region A. Then, as shown in FIG. 2B, a conductive bonding material 32 is applied on the connecting member 28 protruding from the upper surface of the resin mold 30. The conductive bonding material 32 may be, for example, solder or a conductive adhesive. In some embodiments, the conductive bonding material 32 may be applied to the vibrator terminal 52. Then, the piezoelectric vibrator 40 is placed on the resin mold 30. At this time, as shown in FIG. 2C, the piezoelectric vibrator 40 is disposed so that the vibrator terminal 52 and the conductive bonding material 32 are joined, and the vibrator terminal 52 and the connection member 28 are made conductive. As a result, the piezoelectric device 10 having a two-story structure in which the piezoelectric vibrator 40 is mounted on the resin mold 30 is obtained.

In addition, after mounting the piezoelectric vibrator 40 on the resin mold 30, an underfill material may be put in a gap formed between the piezoelectric vibrator 40 and the resin mold 30. By injecting an underfill material, it is possible to prevent the conductive bonding material 32 from melting and the piezoelectric vibrator 40 from rotating during reflow at the customer after the piezoelectric device 10 is shipped.
In some embodiments, the piezoelectric vibrator 40 may be mounted on the resin mold 30 before cutting the sheet substrate 12a, and then the sheet substrate 12a and the like may be cut.

  According to the piezoelectric device 10 and the manufacturing method thereof, since the conduction means 26 and the electronic component 24 are covered with the resin mold 30, they are not exposed to the outside of the resin mold 30. And after covering this conduction | electrical_connection means 26 grade | etc. With the resin mold 30, since the electroconductive joining material 32 is apply | coated to the upper end side of the connection member 28 which protrudes from the upper surface of the resin mold 30, it flows out from this apply | coated location. Further, the conductive bonding material 32 can be prevented from coming into contact with the conduction means 26, the electronic component 24, and the like. That is, the conductive bonding material 32 can prevent the conductive means 26 from being eroded, and the conductive bonding material 32 and the electronic component 24 or the wiring pattern can be prevented from being short-circuited. Conduction can be performed reliably.

  When the connection member 28, the electronic component 24, and the conduction means 26 are covered with the resin mold 30, a plurality of device formation regions A can be molded together by a printing method. For this reason, lead time can be shortened.

  As described with reference to FIG. 2, before mounting the piezoelectric vibrator 40, the sheet substrate 12 a on which the resin mold 30 is formed is cut for each device formation region A, and then the piezoelectric vibrator 40 is attached to the resin. If mounted on the upper surface of the mold 30, it is possible to prevent the side surface (side wall) of the piezoelectric vibrator 40 from being cut during dicing.

  In some embodiments, the connection member 28 and the piezoelectric vibrator 40 can be bonded without using the conductive bonding material 32. That is, a non-conductive paste (NCP) can be used. As a result, the connection member 28 and the vibrator terminal 52 are in direct contact with each other, so that they can be more reliably conducted.

The connecting member 28 described above has a spherical shape. However, the connecting member 28 used in the present invention does not have to be spherical in shape, and may be a cylinder, a prism, or the like. If the shape of the upper end side of the connecting member is a flat surface, the area where the flat portion and the vibrator terminal 52 of the piezoelectric vibrator 40 are electrically and mechanically connected can be increased. Accordingly, the connection between the connecting member and the piezoelectric vibrator 40 can be reliably performed, and the bonding strength between them can be increased.

  Next, a second embodiment will be described. In the second embodiment, an example of an electronic apparatus (digital mobile phone) on which the above-described piezoelectric device 10 is mounted will be described. FIG. 3 is a schematic configuration diagram of a digital mobile phone. The digital cellular phone 60 includes a transmission / reception signal transmission unit 62 and a reception unit 64, and a central processing unit (CPU) 66 that controls them is connected to the transmission unit 62 and the reception unit 64. In addition to modulation and demodulation of transmission / reception signals, the CPU 66 controls an information input / output unit 68 including a display unit and operation keys for inputting information, and a memory 70 including a RAM and a ROM. For this reason, a piezoelectric oscillator 72 is attached to the CPU 66, and its output frequency is used as a clock signal suitable for the control content by a predetermined frequency dividing circuit (not shown) incorporated in the CPU 66. The CPU 66 is connected to a temperature compensated piezoelectric oscillator 74, and the temperature compensated piezoelectric oscillator 74 is connected to the transmitter 62 and the receiver 64. Thus, even if the basic clock from the CPU 66 fluctuates when the environmental temperature changes, it is corrected by the temperature compensated piezoelectric oscillator 74 and supplied to the transmitter 62 and the receiver 64. The piezoelectric device 10 described in the above-described embodiment can be applied to, for example, the piezoelectric oscillator 72 and the temperature compensated piezoelectric oscillator 74.

It is sectional drawing of a piezoelectric device. It is explanatory drawing of the manufacturing process of a piezoelectric device. It is a schematic block diagram of a digital mobile phone.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Piezoelectric device, 12 ... Board | substrate, 12a ... Sheet substrate, 20 ... External terminal, 24 ... Electronic component, 26 ... Conducting means, 28 ... Connection member, 30 ... Resin mold, 32 ... Conductive bonding material, 40 ... Piezoelectric vibration Child, 52 ... vibrator terminal, A ... device formation region.

Claims (6)

Arranging electronic components and connection members for each of a plurality of device forming regions on the sheet substrate;
Forming a resin mold on the sheet substrate to cover the electronic component, and forming an upper surface of the resin mold at a position lower than the top of the connection member;
Fixing the piezoelectric vibrator on the resin mold and conducting the connection member and the piezoelectric vibrator coming out from the upper surface of the resin mold;
A method for manufacturing a piezoelectric device, wherein the steps are performed in order. Bonding a conduction means to the electronic component, conducting the electronic component and the connection member through the conduction means,
The upper surface of the resin mold is formed between the highest part of the conduction means and the upper surface of the upper surface of the electronic component and the top of the connection member.
The method for manufacturing a piezoelectric device according to claim 1.   3. The piezoelectric device according to claim 1, wherein the piezoelectric vibrator is fixed to an upper surface of the resin mold after the sheet substrate on which the resin mold is formed is separated into pieces for each device forming region. Manufacturing method. An electronic component is disposed on one surface of the substrate, and is electrically connected to an external terminal provided on the other surface of the substrate.
A connection member that is electrically connected to the electronic component is provided on one surface of the substrate,
While providing the resin mold around the central portion and the lower end side of the connection member while exposing the upper end side of the connection member to the outside, providing the resin mold around the electronic component,
The piezoelectric vibrator is disposed on the resin mold, and the upper end side of the connection member protruding from the upper surface of the resin mold and the piezoelectric vibrator are joined.
A piezoelectric device characterized by that. The electronic component is electrically connected to the connection member and the external terminal through a wire,
The upper surface of the resin mold is higher than the highest point of the loop of the wire;
The piezoelectric device according to claim 4.   An electronic apparatus comprising the piezoelectric device according to claim 4.

Images