JP4524659B2 - Surface mount type piezoelectric module package and surface mount type piezoelectric module - Google Patents

Description

  The present invention relates to an improvement of a package structure in a surface-mount type piezoelectric oscillator in which an IC component is incorporated on the bottom surface of a package of a piezoelectric vibrator, and in particular, by reducing the package area without reducing the size of the mounted IC component. The present invention relates to a surface-mount piezoelectric oscillator package and a surface-mount piezoelectric oscillator that can be reduced in size.

In the mobile communications market, an increasing number of manufacturers are promoting modularization of parts groups for each function, taking into account the mounting properties, maintenance and handling characteristics of various electrical components, and the commonality of parts between devices. . Further, along with modularization, there is a strong demand for downsizing and cost reduction.
In particular, there is an increasing tendency toward modularization of circuit components that have established functions and hardware configurations, such as a reference oscillation circuit, a PLL circuit, and a synthesizer circuit, and that require high stability and high performance. Furthermore, there is an advantage that a shield structure can be easily established by packaging these component groups as modules.
Examples of surface mount IC components constructed by modularizing and packaging a plurality of related components include piezoelectric vibrators, piezoelectric oscillators, SAW devices, etc., but these functions are maintained at a high level. However, in order to further reduce the size, for example, a two-story module as shown in FIG. 4 is employed.

4 (a), 4 (b) and 4 (c) are longitudinal sectional views showing a conventional configuration of a surface mount type piezoelectric oscillator (crystal oscillator) as a two-story structure type (H type) module, a state before mounting an IC component. FIG. 2 is a bottom perspective view showing the IC component mounting state.
This piezoelectric oscillator has a configuration in which a piezoelectric vibration element 110 and an IC component 115 are mounted in recesses 102 and 103 provided on the upper surface and the lower surface of the package 100, respectively.
The piezoelectric oscillator package 100 has an insulating container 101 having a substantially H-shaped longitudinal section having recesses 102 and 103 on the upper surface and the lower surface, and two opposing sides of the rectangular annular outer bottom surface of the insulating container. Two mounting terminals 105 arranged on the bottom surface of each projecting stepped portion 114, and each mounting terminal 105 and each excitation electrode of the piezoelectric vibration element 110 are electrically connected in the upper surface side recess 102. Two upper side pads 102a provided, an oscillation circuit (amplification circuit for amplifying the excitation signal of the piezoelectric vibration element for oscillation), a temperature compensation circuit (circuit for compensating the frequency-temperature characteristics of the piezoelectric vibration element) In order to mount an IC component 115 including an integrated circuit such as a lower surface side internal pad 103a disposed on the ceiling surface of the lower surface side recess 103, each mounting terminal 105, an upper surface side internal pad 102a, and a lower surface side internal The conductor 106 to conduct between the head 103a, and a. The piezoelectric oscillator connects and fixes the piezoelectric vibration element 110 to the upper surface side internal pad 102a of the package 100 and seals the upper surface side recess 102 with the metal lid 120, and connects and fixes the IC component 115 to the lower surface side internal pad 103a. (Japanese Unexamined Patent Application Publication No. 2002-329839).
When this piezoelectric oscillator is mounted on a printed circuit board, soldering is performed using mounting terminals 105 provided on the bottom surface of each stepped portion 114.
In such a piezoelectric oscillator, a narrow protrusion-like step 114 is formed only along two opposing sides of the outer bottom surface of the insulating container 101, and the other two opposing sides are flat. Therefore, the entire flat surface of the outer bottom surface of the insulating container including the flat area A can be utilized as an IC component mounting space. Therefore, the size of the IC component that can be mounted can be increased as compared with the type in which the four sides of the outer bottom surface of the insulating container are surrounded by the stepped portion, and the gap between the edge of the IC component and the area A is shown in FIG. When the surplus space S is formed as shown in (c), the insulating container can be shortened and reduced in size by the width of the surplus space S in advance.

By the way, in order to further reduce the area of the piezoelectric oscillator, there is only a method for reducing the size of the IC component itself, but in that case, it is necessary to spend enormous development time and development cost. It is difficult to reduce the size and price.
For example, if the area B in which the mounting terminal 105 is not formed on the upper surface of the stepped portion 114 in FIG. 4C can be used as an IC component mounting area, the package area can be reduced. As long as the portion 114 exists, it is impossible to mount an IC component using the area B.
Therefore, as long as the above package structure is adopted, there is a limit to reducing the area of the piezoelectric oscillator, and in order to reduce the size, there has been no choice but to develop a small IC component with the above-mentioned problems.
JP 2002-329839 A

  The present invention has been made in view of the above, and has a piezoelectric vibration element mounted on an internal pad in a recess on the upper surface side of an insulating container for airtight storage, and a surface on which an IC component is mounted on the outer bottom surface of the insulating container. In the mounting type piezoelectric oscillator package, by arranging the four mounting terminals for surface mounting in a line along one side of the outer bottom surface of the insulating container, the space for mounting IC components on the outer bottom surface of the insulating container is expanded, and the package An object of the present invention is to provide a surface-mount type piezoelectric oscillator package and a surface-mount type piezoelectric oscillator capable of reducing the area.

In order to achieve the above object, a surface-mount type piezoelectric module package according to the present invention is electrically connected to an insulating container having a recess on the upper surface and each excitation electrode of the piezoelectric vibration element disposed in the recess. An inner pad, a mounting terminal disposed along one side of the outer bottom surface of the insulating container, a bottom pad disposed on the outer bottom surface of the insulating container for mounting an IC component, the mounting terminal, and the inner pads. And a conductor conducting between the bottom surface pad and the mounting pad, wherein the mounting terminal is disposed on a bottom surface of a stepped portion projecting along one side of the outer bottom surface of the insulating container.
The surface mount type piezoelectric module package of the present invention includes an insulating container having a recess on the upper surface, an internal pad disposed in the recess and electrically connected to each excitation electrode of the piezoelectric vibration element, and the insulation A mounting terminal disposed along one side of the outer bottom surface of the container, a bottom pad disposed on the outer bottom surface of the insulating container for mounting the IC component, and between the mounting terminal, each of the internal pads, and the bottom pad. , And a convex terminal member is electrically and mechanically fixed to the mounting terminal.
The surface mount type piezoelectric module package of the present invention includes an insulating container having a recess on the upper surface, an internal pad disposed in the recess and electrically connected to each excitation electrode of the piezoelectric vibration element, and the insulation A mounting pad disposed along one side of the outer bottom surface of the container, a bottom pad disposed on the outer bottom surface of the insulating container for mounting the IC component, and between the mounting pad , each of the internal pads, and the bottom surface pad. A single columnar terminal member is joined across the mounting pad at a position along the one side of the outer bottom surface of the insulating container, and the columnar terminal member is an insulating base. And a back electrode formed on the back surface of the insulating base and electrically connected to the mounting pad, and a mounting terminal electrically connected to the back electrode and exposed on the bottom surface of the insulating base. It is characterized by.
The surface-mount type piezoelectric module of the present invention is a surface-mount type piezoelectric module configured by using the surface-mount type piezoelectric module package according to the present invention, wherein each excitation electrode of the piezoelectric vibration element is electrically connected to the internal pad. In a connected state, the recess is hermetically sealed with a metal lid, and an IC component is mounted on the bottom pad.
The surface mount type piezoelectric module of the present invention is characterized in that the IC component is integrated with the outer bottom surface of the insulating container by coating with a molding resin.

According to the present invention, a piezoelectric vibration element is mounted on an internal pad in a recess on the upper surface side of an insulating container to be hermetically stored, and an IC component is mounted on a flat outer bottom surface of the insulating container. In the package, since the four mounting terminals for surface mounting are arranged in a line along one side of the outer bottom surface of the insulating container, the IC component mounting space on the outer bottom surface of the insulating container can be expanded to reduce the area of the package. .
In addition, since the piezoelectric oscillator is cantilevered on the mother printed board using the mounting terminals, durability against mechanical shock can be enhanced.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.
FIG. 1A is a longitudinal sectional view of a crystal oscillator as an example of a surface-mount piezoelectric oscillator having a package structure according to an embodiment of the present invention, and FIG. 1B is a bottom perspective view showing an exploded state before mounting an IC component. FIG. 4C is a bottom perspective view in a state where an IC component is mounted.
This crystal oscillator 1 has a configuration in which a crystal resonator element 20 is mounted in a recess 3 provided on the upper surface of the package 2 and hermetically sealed with a metal lid 10, and an IC component 25 is mounted on the outer bottom surface of the package 2. Have.
The package 2 includes an insulating container 4 made of ceramic or the like having a recess 3 on the upper surface, and two internal pads 5 disposed in the recess 3 and electrically connected to each excitation electrode of the crystal resonator element 20. , At least four mounting terminals 6 arranged in a line along one side of the outer bottom surface of the insulating container, and a bottom surface pad 8 disposed on the outer bottom surface 7 of the insulating container for mounting the IC component 25 constituting the oscillation circuit. In addition, a conductor 9 that conducts between each mounting terminal 6, each internal pad 5, and the bottom pad 8, and two internal pads 5 provided in the recess 3 are connected to two on the crystal vibration element (piezoelectric vibration element) 20. And a metal lid 10 for hermetically sealing the recess 3 in a state where the excitation electrodes are electrically connected to each other.
Each mounting terminal 6 includes, for example, a drive power supply mounting terminal (Vcc terminal), a control voltage application mounting terminal (Vcon terminal), and a signal output mounting terminal (Out terminal) that are electrically connected to each terminal on the crystal resonator element side. It consists of four mounting terminals, which are ground mounting terminals (Gnd terminals) for conducting with the ground circuit, and these are arranged in a line along the flat bottom surface of the step portion 11 projecting along one side of the outer bottom surface 7 of the insulating container. They are spaced apart.

The step portion 11 is manufactured at the same time when the insulating container 4 is manufactured through a process of laminating a plurality of ceramic sheets, firing and curing, and has a quadrangular prism shape.
The quartz resonator element 20 has a configuration in which excitation electrodes and lead electrodes extending from the excitation electrodes to the edge of the substrate are formed on both front and back surfaces of the quartz substrate. The two internal pads 5 are connected to the two lead electrodes on the crystal resonator element 20 by a conductive adhesive 21 in a one-to-one relationship.
The IC component 25 includes integrated circuits such as an oscillation circuit (amplification circuit for amplifying the excitation signal of the piezoelectric vibration element for oscillation) and a temperature compensation circuit (circuit for compensating the frequency temperature characteristic of the piezoelectric vibration element). IC chip.
Further, if necessary, a resin (mold resin) 26 as an underfill is filled to cover the IC component 25.
The package 2 (insulating container 4) according to this embodiment has a rectangular planar shape, a substantially L-shaped cross section, and a bottom surface pad 8 for mounting an IC component on an outer bottom surface 7 having a large area. Since the mounting terminals 6 for surface mounting are spaced apart from each other at a predetermined interval on the bottom surface of the step portion 11 projecting along one side of the outer bottom surface 7, the other side facing the one side on which the step portion 11 is formed is a flat surface. Thus, in the conventional type in which two stepped portions are arranged opposite to each other as shown in the conventional example, a space for mounting IC components can be secured on the outer bottom surface 7 by removing one stepped portion. . Therefore, the crystal oscillator can be reduced in size and price.

Next, FIGS. 2A and 2B are a longitudinal sectional view and a bottom perspective view of a crystal oscillator as an example of a surface-mount piezoelectric oscillator having a package structure according to a second embodiment of the present invention. .
This crystal oscillator 1 has a configuration in which a crystal resonator element 20 is mounted in a recess 3 provided on the upper surface of the package 2 and hermetically sealed with a metal lid 10, and an IC component 25 is mounted on the outer bottom surface of the package 2. Have.
The package 2 of the crystal oscillator 1 according to this embodiment includes an insulating container 4 having a recess 3 on the upper surface, and an interior disposed in the recess 3 and electrically connected to each excitation electrode of the crystal resonator element 20. In order to mount the pad 5, at least four mounting terminals 6 arranged in a line along one side (flat surface) of the entire flat outer bottom surface 7 of the insulating container 4, and the IC component 25 constituting the oscillation circuit A bottom surface pad 8 disposed on the outer bottom surface 7 of the insulating container, and a conductor 9 that conducts between each mounting terminal 6, each internal pad 5, and the bottom surface pad 8 are provided. Further, a metal ball as the convex terminal member 30 is electrically and mechanically fixed to the mounting terminal 6.
After the convex terminal member 30 is fixed to each mounting terminal 6 by thermocompression bonding or soldering, the entire surface of the IC component 25 and a part of the convex terminal member 30 are covered with the mold resin 26.
The package 2 (insulating container 4) according to this embodiment is a flat plate having a rectangular planar shape, and there are no protrusions or the like that hinder the mounting of IC components on the entire flat outer bottom surface. Since a bottom surface pad 8 for mounting an IC component is formed on the entire flat outer bottom surface 7, and the mounting terminals 6 for surface mounting are spaced apart in a row at a predetermined interval along one side of the outer bottom surface 7, As compared with the conventional type in which two stepped portions are arranged to face each other as shown in the example, a space for mounting IC components can be secured on the outer bottom surface 7 by removing one stepped portion. Therefore, the crystal oscillator can be reduced in size and price.

Next, FIGS. 3A and 3B are a longitudinal sectional view and a bottom perspective view of a crystal oscillator as an example of a surface mount piezoelectric oscillator having a package structure according to a third embodiment of the present invention. .
This crystal oscillator 1 has a configuration in which a crystal resonator element 20 is mounted in a recess 3 provided on the upper surface of a package 2 and sealed with a metal lid 10, and an IC component 25 is mounted on the outer bottom surface of the package 2. is doing.
The package 2 of the crystal oscillator 1 according to this embodiment includes an insulating container 4 having a recess 3 on the upper surface, and an interior disposed in the recess 3 and electrically connected to each excitation electrode of the crystal resonator element 20. The bottom surface disposed on the outer bottom surface 7 of the insulating container for mounting the pad 5, at least four mounting pads 35 arranged in a line along one side of the outer bottom surface of the insulating container 4, and the IC component 25 constituting the oscillation circuit. A pad 8 and a conductor 9 that conducts between each mounting pad 35, each internal pad 5, and the bottom surface pad 8 are provided.
Furthermore, a single columnar terminal member 40 is joined across each mounting pad 35 at a position along one side of the insulating container outer bottom surface 7. The columnar terminal member 40 includes a rectangular columnar insulating base 41 made of an insulating material, a back electrode 42 formed on the back surface of the insulating base 41 and individually connected to each mounting pad 35, and individually connected to each back electrode 42. And mounting terminals 43 exposed on the bottom surface of the insulating base.
In this embodiment, the insulating container outer bottom surface 7 is entirely flat, and the columnar terminal members 40 are joined and integrated on the four mounting pads 35 arranged in a line along one edge of the outer bottom surface 7. Accordingly, surface mounting using the mounting terminals 43 provided on the bottom surface of the columnar terminal member 40 is possible.
After fixing the IC component 25 and the columnar terminal member 40 to the outer bottom surface 7 of the insulating container, the IC component 25 is covered and integrated with the mold resin 26.

The package 2 (insulating container 4) according to this embodiment is a flat plate having a rectangular planar shape, and there are no protrusions or the like that hinder the mounting of IC components on the entire flat outer bottom surface. A bottom pad 8 for mounting an IC component is formed on the outer flat surface 7 that is flat on the entire surface, and mounting pads 35 are spaced apart in a row along one side of the outer bottom surface 7. In addition, since the columnar terminal member 40 having the mounting terminal 43 is joined to the bottom surface, it is removed by removing one step portion as compared with the conventional type in which the two step portions are opposed to each other as shown in the conventional example. A wide space for mounting IC components can be secured on the bottom surface 7. Therefore, the crystal oscillator can be reduced in size and price.
The piezoelectric oscillator according to the present invention is mounted in a cantilevered manner on the mother printed circuit board by mounting terminals 6 and 43 provided along one side of the outer bottom surface of the package. Can be made to have a structure with better mechanical shock resistance than when rigidly mounted.
In the above embodiment, a crystal oscillator is illustrated as a typical example of a piezoelectric oscillator. However, the present invention can be applied to an oscillator using a piezoelectric vibration element made of a piezoelectric material.

(A) is a longitudinal sectional view of a crystal oscillator as an example of a surface-mount piezoelectric oscillator having a package structure according to an embodiment of the present invention, (b) is a bottom perspective view showing an exploded state before mounting an IC component, (C) is a bottom perspective view in a state where an IC component is mounted. (A) And (b) is a longitudinal cross-sectional view and bottom perspective view of a crystal oscillator as an example of a surface-mount piezoelectric oscillator having a package structure according to a second embodiment of the present invention. (A) And (b) is a longitudinal cross-sectional view and bottom perspective view of a crystal oscillator as an example of a surface mount piezoelectric oscillator having a package structure according to a third embodiment of the present invention. (A), (b) and (c) are longitudinal sectional views showing a conventional configuration of a surface-mount type piezoelectric oscillator (crystal oscillator) as a two-story structure type (H type) module, and a bottom perspective view showing a state before mounting an IC component. The bottom perspective view which shows a figure and an IC component mounting state.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Crystal oscillator, 2 ... Package, 3 ... Recess, 4 ... Insulation container, 5 ... Internal pad, 6 ... Mounting terminal, 7 ... Outer bottom surface, 8 ... Bottom pad, 9 ... Conductor, 10 ... Metal lid, 11 ... Step part 20 ... Quartz vibration element 21 ... Conductive adhesive 25 ... IC component 26 ... Mold resin 30 ... Convex terminal member 35 ... Mounting pad 40 ... Column terminal member 41 ... Insulating base 42 ... back electrode, 43 ... mounting terminal.

Claims (5)

An insulating container having a recess on the top surface, an internal pad disposed in the recess and electrically connected to each excitation electrode of the piezoelectric vibration element, and a mounting disposed along one side of the outer bottom surface of the insulating container A terminal, a bottom surface pad disposed on the outer bottom surface of the insulating container for mounting the IC component, and a conductor that conducts between the mounting terminal, each internal pad, and the bottom surface pad,
The surface-mount type piezoelectric module package according to claim 1, wherein the mounting terminal is disposed on a bottom surface of a stepped portion projecting along one side of the outer bottom surface of the insulating container. An insulating container having a recess on the top surface, an internal pad disposed in the recess and electrically connected to each excitation electrode of the piezoelectric vibration element, and a mounting disposed along one side of the outer bottom surface of the insulating container A terminal, a bottom surface pad disposed on the outer bottom surface of the insulating container for mounting the IC component, and a conductor that conducts between the mounting terminal, each internal pad, and the bottom surface pad,
A surface mount type piezoelectric module package, wherein a convex terminal member is electrically and mechanically fixed to the mounting terminal. An insulating container having a recess on the top surface, an internal pad disposed in the recess and electrically connected to each excitation electrode of the piezoelectric vibration element, and a mounting disposed along one side of the outer bottom surface of the insulating container A pad, a bottom surface pad disposed on the outer bottom surface of the insulating container for mounting an IC component, and a conductor that conducts between the mounting pad , each internal pad, and the bottom surface pad,
At a position along the one side of the outer bottom surface of the insulating container, a single columnar terminal member is joined across the mounting pad,
The columnar terminal member includes an insulating base, a back electrode formed on the back surface of the insulating base and individually connected to the mounting pad, and a mounting electrically connected to the back electrode and exposed on the bottom surface of the insulating base. And a surface mount type piezoelectric module package.   A surface mount type piezoelectric module configured using the surface mount type piezoelectric module package according to claim 1, 2, or 3, wherein each excitation electrode of a piezoelectric vibration element is electrically connected to the internal pad. The surface-mount type piezoelectric module is characterized in that the recess is hermetically sealed with a metal lid, and an IC component is mounted on the bottom pad.   The surface-mount type piezoelectric module according to claim 4, wherein the IC component is integrated with the outer bottom surface of the insulating container by covering with a molding resin.

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