JP2012160963A - Saw oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve productivity and reliability by reducing a frequency deviation between before and after seam welding.SOLUTION: A SAW oscillator includes: an element mounting member 10 comprising a flat substrate part 11, a frame part 12 disposed on one principal surface of the substrate part 11 to form a recessed region, a mounting part 13 disposed on the substrate part 11 within the recessed region, and a cushioning part 14a disposed on the substrate part 11 within the recessed region; a surface acoustic wave element 30 disposed on the mounting part 13; an integrated circuit element 20 mounted on the element mounting member 10; and a lid member 40 closing the recessed region. The surface acoustic wave element 30 is cantilevered over the substrate part 11 within the recessed region. The cushioning part 14a is disposed in the position where a first centerline CL1 passing the center of a principal surface of the mounting part 13 facing the lid member and parallel to one longer side over the principal surface of the substrate part 11 within the recessed region intersects a second centerline CL2 passing the middles of two longer sides over the principal surface of the substrate part 11 within the recessed region.

Description

  The present invention relates to a SAW oscillator used in electronic equipment.

Conventionally, piezoelectric oscillators have been widely used as timing devices incorporated in electronic equipment.
Here, a SAW oscillator which is one of electronic devices will be described.

  For example, a SAW oscillator includes a flat plate-shaped substrate portion, a frame portion in which a concave portion provided on one main surface of the substrate portion is formed, and a bonding metal layer is formed on the main surface facing the substrate portion side. An element mounting member comprising: a mounting portion provided on the substrate portion exposed to the inside of the concave portion; and a buffer portion provided on the substrate portion exposed to the inner side of the concave portion; and conductive adhesion on the mounting portion A rectangular surface acoustic wave element provided via an agent, an integrated circuit element mounted on the element mounting member, and a lid member that closes the recess. The surface acoustic wave device is mounted in a cantilever state on the mounting portion. At this time, the surface acoustic wave element has a comb-like electrode pattern on one main surface and a grid-like reflective electrode pattern on both sides so as to sandwich the electrode pattern, and the free end side of the other main surface is a buffer portion In contact with.

JP-A-6-291593

  However, in the conventional SAW oscillator, the element mounting member on which the surface acoustic wave element is mounted and the lid member are sealed by seam welding via a joining metal layer provided on a frame portion of the element mounting member. By stopping, warpage occurs in the longitudinal direction of the element mounting member. This warp pushes up the buffer portion provided in the element mounting member, and applies stress to the surface acoustic wave device in contact with the buffer portion. Here, using a graph in which the difference between the frequency after seam welding (hereinafter referred to as frequency deviation) with the frequency before seam welding as a reference in such a SAW oscillator is used as a frequency value on the vertical axis and the measurement item on the horizontal axis. explain. In addition, for example, the upper limit frequency fluctuation value (hereinafter referred to as the upper limit value) on the graph is based on the frequency before seam welding and the difference from the frequency after seam welding is maximum in the plus direction. It is the value that became. Further, the lower limit frequency fluctuation value (hereinafter referred to as the lower limit value) on the graph is a value in which the difference from the frequency after seam welding is minimized from the upper limit value based on the frequency before seam welding. At this time, the frequency deviation at the position of the conventional buffer portion is from the upper limit value + 7.0E × −06 to the lower limit value −19.0E × −06, and the range between the upper limit value and the lower limit value is large, and the productivity of the SAW oscillator is increased. And may reduce reliability.

  Accordingly, an object of the present invention is to provide a SAW oscillator that solves the above-described problems, has a small frequency deviation, and has improved productivity and reliability.

  In order to solve the above-mentioned problems, the present invention provides a flat plate-like substrate portion, a concave portion provided on one main surface of the substrate portion, and a metal layer for bonding on the main surface facing the substrate portion side. Formed on the substrate portion inside the recess, a buffer portion provided on the substrate portion inside the recess, and an element mounting member configured on the mounting portion. A surface acoustic wave element having a rectangular shape provided with a conductive adhesive, an integrated circuit element mounted on the element mounting member, and a lid member that closes the recess, and the surface acoustic wave element is cantilevered Supported and provided on the substrate portion inside the recess. For example, the buffer part passes through the center of the main surface facing the lid member side of the mounting part, passes through the center of the main part of the substrate part of the concave part and is parallel to one long side, and the substrate of the concave part It is provided in the position which cross | intersects with the 2nd centerline which passes along the center of two long sides on the main surface of a part.

  In the present invention, a flat substrate portion and a concave portion are formed on one main surface of the substrate portion, and a bonding metal layer is formed on the main surface facing the substrate portion side. An element mounting member comprising a frame, a mounting portion provided on the substrate portion inside the recess, and a buffer portion provided on the substrate portion inside the recess, and a conductive adhesive on the mounting portion A surface acoustic wave element having a quadrangular shape, an integrated circuit element mounted on the element mounting member, and a lid member that closes the recess, the surface acoustic wave element being cantilevered, and the recess It is provided on the inner substrate portion. The buffer portion passes through the center of the main surface facing the lid member side of the mounting portion, passes through the center of the main surface of the substrate portion of the recess and is parallel to one long side, and the substrate portion of the recess 8% of the long side dimension of the substrate portion of the recess from the position where the second center line passing through the center of the two long sides intersects the free end of the surface acoustic wave element. It is in the position.

  In the present invention, a flat substrate portion and a concave portion are formed on one main surface of the substrate portion, and a bonding metal layer is formed on the main surface facing the substrate portion side. An element mounting member comprising a frame, a mounting portion provided on the substrate portion inside the recess, and a buffer portion provided on the substrate portion inside the recess, and a conductive adhesive on the mounting portion A surface acoustic wave element having a quadrangular shape, an integrated circuit element mounted on the element mounting member, and a lid member that closes the recess, the surface acoustic wave element being cantilevered, and the recess It is provided on the inner substrate portion. The buffer portion passes through the center of the main surface facing the lid member side of the mounting portion, passes through the center of the main surface of the substrate portion of the recess and is parallel to one long side, and the substrate portion of the recess 16% of the long side dimension of the substrate portion of the concave portion from the position where the second center line passing through the center of the two long sides intersects the free end of the surface acoustic wave element. It is in the position.

  In the present invention, a flat substrate portion and a concave portion are formed on one main surface of the substrate portion, and a bonding metal layer is formed on the main surface facing the substrate portion side. An element mounting member comprising a frame, a mounting portion provided on the substrate portion inside the recess, and a buffer portion provided on the substrate portion inside the recess, and a conductive adhesive on the mounting portion A surface acoustic wave element having a quadrangular shape, an integrated circuit element mounted on the element mounting member, and a lid member that closes the recess, the surface acoustic wave element being cantilevered, and the recess It is provided on the inner substrate portion. The buffer portion passes through the center of the main surface facing the lid member side of the mounting portion, passes through the center of the main surface of the substrate portion of the recess and is parallel to one long side, and the substrate portion of the recess 16% of the long side dimension of the substrate portion of the recess is shifted from the position where the second center line passing through the center of the two long sides intersects the free end of the surface acoustic wave device. It is characterized by being in position.

  According to such a SAW oscillator of the present invention, the surface acoustic wave element is formed by seam welding the element mounting member and the lid member via the joining metal layer provided on the frame portion of the element mounting member. By sealing, the lid member is heated and the joining metal layer provided on the frame portion of the lid member and the element mounting member is melted and joined. At this time, when the heat of the heated and melted metal portion cools, the metal contracts and warps in the longitudinal direction of the element mounting member. This warping pushes up the buffer portion provided in the element mounting member, but the position of the buffer portion passes through the center of the main surface facing the lid member side of the mounting portion and is on the main surface of the substrate portion of the recess. The first center line that is parallel to one long side and the second center line that passes through the center of the two long sides on the main surface of the substrate portion of the recess are provided at a position where they intersect. Therefore, it is possible to make it difficult for the buffer portion to push up the surface acoustic wave element. Therefore, the SAW oscillator of the present invention can reduce the frequency deviation after seam welding, and can improve productivity and reliability.

  According to the SAW oscillator of the present invention, the surface acoustic wave element is formed by seam welding of the element mounting member and the lid member via the metal layer for bonding provided on the frame portion of the element mounting member. By sealing, the lid member is heated, and the joining metal layer provided on the lid member and the frame portion of the element mounting member is melted and joined. At this time, when the heat of the heated and melted metal portion cools, the metal contracts and warps in the longitudinal direction of the element mounting member. This warping pushes up the buffer portion provided in the element mounting member, but the position of the buffer portion passes through the center of the main surface facing the lid member side of the mounting portion and is on the main surface of the substrate portion of the recess. The surface acoustic wave from a position where a first center line parallel to one long side and a second center line passing through the center of the two long sides on the main surface of the substrate portion of the recess intersect. Since it is provided at a position shifted by 8% of the long side dimension of the substrate portion of the concave portion toward the free end side of the device, the buffer portion can make it difficult to push up the surface acoustic wave device. Therefore, the SAW oscillator of the present invention can reduce the frequency deviation after seam welding, and can improve productivity and reliability.

  According to the SAW oscillator of the present invention, the surface acoustic wave element is formed by seam welding of the element mounting member and the lid member via the metal layer for bonding provided on the frame portion of the element mounting member. By sealing, the lid member is heated, and the joining metal layer provided on the lid member and the frame portion of the element mounting member is melted and joined. At this time, when the heat of the heated and melted metal portion cools, the metal contracts and warps in the longitudinal direction of the element mounting member. This warping pushes up the buffer portion provided in the element mounting member, but the position of the buffer portion passes through the center of the main surface facing the lid member side of the mounting portion and is on the main surface of the substrate portion of the recess. The surface acoustic wave from a position where a first center line parallel to one long side and a second center line passing through the center of the two long sides on the main surface of the substrate portion of the recess intersect. Since it is provided at a position shifted toward the free end side of the element by 16% of the long side dimension of the substrate portion of the concave portion, the buffer portion can make it difficult to push up the surface acoustic wave element. Therefore, the SAW oscillator of the present invention can reduce the frequency deviation after seam welding, and can improve productivity and reliability.

  According to the SAW oscillator of the present invention, the surface acoustic wave element is formed by seam welding of the element mounting member and the lid member via the metal layer for bonding provided on the frame portion of the element mounting member. By sealing, the lid member is heated, and the joining metal layer provided on the lid member and the frame portion of the element mounting member is melted and joined. At this time, when the heat of the heated and melted metal portion cools, the metal contracts and warps in the longitudinal direction of the element mounting member. This warping pushes up the buffer portion provided in the element mounting member, but the position of the buffer portion passes through the center of the main surface facing the lid member side of the mounting portion and is on the main surface of the substrate portion of the recess. The surface acoustic wave from a position where a first center line parallel to one long side and a second center line passing through the center of the two long sides on the main surface of the substrate portion of the recess intersect. Since it is provided on the free end side of the element up to a position shifted by 16% of the long side dimension of the substrate portion of the concave portion, the buffer portion can make it difficult to push up the surface acoustic wave element. Therefore, the SAW oscillator of the present invention can reduce the frequency deviation after seam welding, and can improve productivity and reliability.

1 is an exploded perspective view showing an example of a SAW oscillator according to a first embodiment of the present invention. It is a schematic diagram of the element mounting member used for the SAW oscillator which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows an example of the SAW oscillator which concerns on embodiment of this invention. It is a schematic diagram of the element mounting member used for the SAW oscillator which concerns on the 2nd Embodiment of this invention. It is a schematic diagram of the element mounting member used for the SAW oscillator which concerns on the 3rd Embodiment of this invention. It is a graph of the difference of the frequency before seam welding and the frequency after seam welding in a SAW oscillator, (a) is a graph of the frequency deviation in 1st Embodiment, (b) is the frequency deviation in 2nd Embodiment. It is a graph, (c) is a graph of the frequency deviation in 3rd Embodiment. An example of a conventional SAW oscillator is shown, (a) is a sectional view of the SAW oscillator, (b) is a schematic plan view of an element mounting member in the SAW oscillator, and (c) is a frequency deviation at a conventional position. It is a graph of.

  The best mode for carrying out the present invention (hereinafter referred to as “embodiment”) will be described in detail with reference to the drawings as appropriate. Note that each component is exaggerated for easy understanding of the state.

(First embodiment)
As shown in FIGS. 1 and 2, the SAW oscillator 100 according to the first embodiment of the present invention includes an element mounting member 10 having a recess and a buffer portion 14a formed inside the recess, and the element mounting member. The surface acoustic wave element 30 mounted inside the concave portion 10, the integrated circuit element 20 mounted inside the concave portion of the element mounting member 10, and the lid member 40 that closes the concave portion.

  The element mounting member 10 includes a flat substrate portion 11, a frame portion 12 provided on one main surface of the substrate portion 11 to form a recess, a mounting portion 13 provided on the substrate portion inside the recess, And a buffer portion 14a provided on the substrate portion inside the recess.

  The substrate portion 11 is made of, for example, a ceramic material such as alumina ceramics. An integrated circuit element mounting pad (not shown) formed on one main surface of the substrate portion 11 and a predetermined wiring conductor are formed inside the substrate. An external terminal (not shown) is formed on the other main surface.

  The frame portion 12 is made of a ceramic material such as alumina ceramics like the substrate portion 11 and is provided on one main surface of the substrate portion 11 to form a recess. Further, the frame portion 12 has a metal layer 16 for bonding formed on the main surface facing the substrate portion side.

  The mounting portion 13 is made of a ceramic material such as alumina ceramic, and is located at a predetermined corner on the substrate portion inside the recess. Further, the mounting portion 13 is formed in, for example, a quadrangular shape in plan view, and has a predetermined thickness. The mounting portion 13 is used for mounting the surface acoustic wave element 30.

  The buffer portion 14a is made of, for example, a silicon-based material, and is provided on the substrate portion 11 inside the recess. For example, the buffer portion 14a includes a first center line CL1 passing through the center of the main surface facing the lid member side of the mounting portion 13 and parallel to one long side on the main surface of the substrate portion 11 of the recess, On the main surface of the substrate portion 11 of the recess, the second center line CL2 passing through the center of the long side in the two recesses is provided at a position where it intersects.

  The surface acoustic wave element 30 includes a piezoelectric element, an electrode pattern formed on one main surface of the piezoelectric element, and a reflective electrode pattern formed on the same plane as the electrode pattern. The electrode pattern and the reflective electrode pattern are not formed on the other main surface of the piezoelectric element. The surface acoustic wave element 30 is mechanically cantilevered on the mounting portion 13 with the other main surface facing the mounting portion 13 via a conductive adhesive 15. The electrode pattern is formed in a comb shape at the center on one main surface of the piezoelectric element. In addition, the reflective electrode pattern is formed in a lattice shape on both sides so as to sandwich the electrode pattern on the same surface on which the electrode pattern is formed. At this time, when the surface acoustic wave element 30 is mounted on the mounting portion 13, one main surface of the surface acoustic wave element 30 faces the buffer portion 14 a.

  The integrated circuit element 20 is provided at a position facing the surface acoustic wave element 30 on the substrate portion inside the recess. The integrated circuit element 20 is electrically connected to the surface acoustic wave element 30 by wire bonding, and is electrically connected to an integrated circuit element mounting pad formed on one main surface of the substrate portion 11 (not shown). It is connected to the. The integrated circuit element 20 controls the transmission output based on the vibration of the surface acoustic wave element 30 (not shown). Further, the integrated circuit element 20 is provided on the substrate portion 11 on the substrate portion 11 inside the recess, and both the surface acoustic wave element 30 and the mounting portion 13 are provided on the substrate portion 11.

  The lid member 40 is made of, for example, a metal material and is formed of a square metal. The lid member 40 is joined by seam welding through the element mounting member 10 and the joining metal layer 16 provided on the frame portion 12 of the element mounting member 10.

  Seam welding is a welding method in which a large current is passed through a welded portion to heat the welded portion and apply pressure.

  As shown in FIGS. 2 and 3, by seam welding the element mounting member 10 and the lid member 40 via a joining metal layer 16 provided on the frame portion 12 of the element mounting member 10, The lid member 40 is heated and the joining metal layer 16 provided on the frame portion 12 of the element mounting member 10 is melted and joined. At this time, when the heat of the heated and melted metal portion cools, the metal contracts and warps in the longitudinal direction of the element mounting member 10. This warp pushes up the buffer portion 14a provided in the element mounting member 10, but passes through the center of the main surface facing the lid member side of the mounting portion 13 and is on the main surface of the substrate portion 11 of the recess. The first center line CL1 that is parallel to the long side and the second center line CL2 that passes through the center of the two long sides on the main surface of the substrate portion 11 of the recess are provided at a position where they intersect. Therefore, the surface acoustic wave element 30 is less likely to receive stress due to the buffer portion 14a.

  In the graph of FIG. 6A, the difference between the frequency after seam welding (hereinafter referred to as the frequency deviation) with the frequency before seam welding of the SAW oscillator in the first embodiment as a reference, and the frequency on the vertical axis. It is a graph with a value and a measurement item on the horizontal axis. Further, for example, the upper limit frequency fluctuation value (hereinafter referred to as the upper limit value) on the graph is a value in which the difference from the frequency after seam welding is maximized in the positive direction with reference to the frequency before seam welding. Further, the lower limit frequency fluctuation value (hereinafter referred to as the lower limit value) on the graph is a value in which the difference from the frequency after seam welding is minimized from the upper limit value based on the frequency before seam welding. At this time, as shown in FIG. 6A, the frequency deviation is from the upper limit value + 7.0E × −06 to the lower limit value + 0.5E × −06, and at the conventional buffer portion position 214 of FIG. 7B. When compared with the upper limit value + 7.0E × −06, which is a frequency deviation of the above, from the lower limit value −19.0E × −06, the range of the upper limit value and the lower limit value at the position of the first embodiment is The width at the position of the first embodiment is smaller than the width between the upper limit value and the lower limit value. Therefore, the first embodiment can improve the productivity and reliability of the SAW oscillator.

(Second Embodiment)
As shown in FIGS. 1 and 4, the SAW oscillator 100 according to the second embodiment of the present invention includes an element mounting member 10 having a recess and a buffer portion 14b formed inside the recess, and the element mounting member. The surface acoustic wave element 30 mounted inside the concave portion 10, the integrated circuit element 20 mounted inside the concave portion of the element mounting member 10, and the lid member 40 that closes the concave portion.

  The element mounting member 10 includes a flat substrate portion 11, a frame portion 12 provided on one main surface of the substrate portion 11 to form a recess, a mounting portion 13 provided on the substrate portion inside the recess, The buffer part 14b provided on the board | substrate part inside a recessed part is formed.

  The substrate portion 11 is made of, for example, a ceramic material such as alumina ceramics. An integrated circuit element mounting pad (not shown) formed on one main surface of the substrate portion 11 and a predetermined wiring conductor are formed inside the substrate. An external terminal (not shown) is formed on the other main surface.

  The frame portion 12 is made of a ceramic material such as alumina ceramics like the substrate portion 11 and is provided on one main surface of the substrate portion 11 to form a recess. Further, the frame portion 12 has a metal layer 16 for bonding formed on the main surface facing the substrate portion side.

  The mounting portion 13 is made of a ceramic material such as alumina ceramic, and is located at a predetermined corner on the substrate portion inside the recess. Further, the mounting portion 13 is formed in, for example, a quadrangular shape in plan view, and has a predetermined thickness. The mounting portion 13 is used for mounting the surface acoustic wave element 30.

  The buffer portion 14b is made of, for example, a silicon-based material, and is provided on the substrate portion 11 inside the recess. For example, the buffer portion 14b passes through the center of the main surface facing the lid member side of the mounting portion 13 and passes through the center of the main surface of the substrate portion 11 of the recess and is parallel to one long side, From the position where the second center line CL2 passing through the center of the long side in the two recesses on the main surface of the substrate portion 11 of the recess crosses toward the free end of the surface acoustic wave element 30, the recess In the substrate portion 11, the position is shifted by 8% of the long side dimension.

  The surface acoustic wave element 30 includes a piezoelectric element, an electrode pattern formed on one main surface of the piezoelectric element, and a reflective electrode pattern formed on the same plane as the electrode pattern. The electrode pattern and the reflective electrode pattern are not formed on the other main surface of the piezoelectric element. The surface acoustic wave element 30 is mechanically cantilevered on the mounting portion 13 with the other main surface facing the mounting portion 13 via a conductive adhesive 15. The electrode pattern is formed in a comb shape at the center on one main surface of the piezoelectric element. In addition, the reflective electrode pattern is formed in a lattice shape on both sides so as to sandwich the electrode pattern on the same surface on which the electrode pattern is formed. At this time, when the surface acoustic wave element 30 is mounted on the mounting portion 13, one main surface of the surface acoustic wave element 30 is opposed to the buffer portion 14b.

  The integrated circuit element 20 is provided at a position facing the surface acoustic wave element 30 on the substrate portion inside the recess. The integrated circuit element 20 is electrically connected to the surface acoustic wave element 30 by wire bonding, and is electrically connected to an integrated circuit element mounting pad formed on one main surface of the substrate portion 11 (not shown). It is connected to the. The integrated circuit element 20 controls the transmission output based on the vibration of the surface acoustic wave element 30 (not shown). Further, the integrated circuit element 20 is provided on the substrate portion 11 on the substrate portion 11 inside the recess, and both the surface acoustic wave element 30 and the mounting portion 13 are provided on the substrate portion 11.

  The lid member 40 is made of, for example, a metal material and is formed of a square metal. The lid member 40 is joined by seam welding through the element mounting member 10 and the joining metal layer 16 provided on the frame portion 12 of the element mounting member 10.

  Seam welding is a welding method in which a large current is passed through a welded portion to heat the welded portion and apply pressure.

  As shown in FIGS. 3 and 4, by seam welding the element mounting member 10 and the lid member 40 through a metal layer 16 for bonding provided on the frame portion 12 of the element mounting member 10, The lid member 40 is heated and the joining metal layer 16 provided on the frame portion 12 of the element mounting member 10 is melted and joined. At this time, when the heat of the heated and melted metal portion cools, the metal contracts and warps in the longitudinal direction of the element mounting member 10. This warp pushes up the buffer portion 14b provided in the element mounting member 10, but passes through the center of the main surface facing the lid member side of the mounting portion 13 and is on the main surface of the substrate portion 11 of the recess. The surface acoustic wave from a position where the first center line CL1 parallel to the long side and the second center line CL2 passing through the center of the two long sides on the main surface of the substrate portion 11 of the recess intersect. The surface acoustic wave element 30 is less likely to be stressed by the buffer portion 14b because it faces the free end of the element 30 and is displaced by 8% of the long side dimension of the substrate portion 11 of the recess.

  In the graph of FIG. 6B, the difference between the frequency after seam welding (hereinafter, referred to as frequency deviation) with the frequency before seam welding of the SAW oscillator in the second embodiment as a reference, and the frequency on the vertical axis. It is a graph with a value and a measurement item on the horizontal axis. Further, for example, the upper limit frequency fluctuation value (hereinafter referred to as the upper limit value) on the graph is a value in which the difference from the frequency after seam welding is maximized in the positive direction with reference to the frequency before seam welding. Further, the lower limit frequency fluctuation value (hereinafter referred to as the lower limit value) on the graph is a value in which the difference from the frequency after seam welding is minimized from the upper limit value based on the frequency before seam welding. At this time, as shown in FIG. 6B, the frequency deviation is from the upper limit value + 5.0E × −06 to the lower limit value −1.5E × −06, and the conventional buffer portion position 214 of FIG. As compared with the upper limit value + 7.0E × −06, which is a frequency deviation at the lower limit value −19.0E × −06, the range of the upper limit value and the lower limit value in the second embodiment position is the same as that in the conventional buffer portion position. The width at the position of the second embodiment is smaller than the width between the upper limit value and the lower limit value. Therefore, the second embodiment can improve the productivity and reliability of the SAW oscillator.

  Thus, also in the position of the buffer part 14b which concerns on the 2nd Embodiment of this invention, there exists an effect equivalent to 1st Embodiment.

(Third embodiment)
As shown in FIGS. 1 and 5, a SAW oscillator 100 according to a third embodiment of the present invention includes an element mounting member 10 having a recess and a buffer portion 14 c formed inside the recess, and the element mounting member. The surface acoustic wave element 30 mounted inside the concave portion 10, the integrated circuit element 20 mounted inside the concave portion of the element mounting member 10, and the lid member 40 that closes the concave portion.

  The element mounting member 10 includes a flat substrate portion 11, a frame portion 12 provided on one main surface of the substrate portion 11 to form a recess, a mounting portion 13 provided on the substrate portion inside the recess, The buffer part 14c provided on the board | substrate part inside a recessed part is formed.

  The substrate portion 11 is made of, for example, a ceramic material such as alumina ceramics. An integrated circuit element mounting pad (not shown) formed on one main surface of the substrate portion 11 and a predetermined wiring conductor are formed inside the substrate. An external terminal (not shown) is formed on the other main surface.

  The frame portion 12 is made of a ceramic material such as alumina ceramics like the substrate portion 11 and is provided on one main surface of the substrate portion 11 to form a recess. Further, the frame portion 12 has a metal layer 16 for bonding formed on the main surface facing the substrate portion side.

  The mounting portion 13 is made of a ceramic material such as alumina ceramic, and is located at a predetermined corner on the substrate portion inside the recess. Further, the mounting portion 13 is formed in, for example, a quadrangular shape in plan view, and has a predetermined thickness. The mounting portion 13 is used for mounting the surface acoustic wave element 30.

  The buffer portion 14c is made of, for example, a silicon-based material and is provided on the substrate portion 11 inside the recess. For example, the buffer portion 14c passes through the center of the main surface facing the lid member side of the mounting portion 13 and passes through the center of the main surface of the substrate portion 11 of the recess and is parallel to one long side, From the position where the second center line CL2 passing through the center of the long side in the two recesses on the main surface of the substrate portion 11 of the recess crosses toward the free end of the surface acoustic wave element 30, the recess In the substrate portion 11, the position is shifted by 16% of the long side dimension.

The surface acoustic wave element 30 includes a piezoelectric element, an electrode pattern formed on one main surface of the piezoelectric element, and a reflective electrode pattern formed on the same plane as the electrode pattern. The electrode pattern and the reflective electrode pattern are not formed on the other main surface of the piezoelectric element. The surface acoustic wave element 30 is mechanically cantilevered on the mounting portion 13 with the other main surface facing the mounting portion 13 via a conductive adhesive 15. The electrode pattern is formed in a comb shape at the center on one main surface of the piezoelectric element.
In addition, the reflective electrode pattern is formed in a lattice shape on both sides so as to sandwich the electrode pattern on the same surface on which the electrode pattern is formed. At this time, when the surface acoustic wave element 30 is mounted on the mounting portion 13, one main surface of the surface acoustic wave element 30 faces the buffer portion 14 c.

  The integrated circuit element 20 is provided at a position facing the surface acoustic wave element 30 on the substrate portion inside the recess. The integrated circuit element 20 is electrically connected to the surface acoustic wave element 30 by wire bonding, and is electrically connected to an integrated circuit element mounting pad formed on one main surface of the substrate portion 11 (not shown). It is connected to the. The integrated circuit element 20 controls the transmission output based on the vibration of the surface acoustic wave element 30 (not shown). Further, the integrated circuit element 20 is provided on the substrate portion 11 on the substrate portion 11 inside the recess, and both the surface acoustic wave element 30 and the mounting portion 13 are provided on the substrate portion 11.

  The lid member 40 is made of, for example, a metal material and is formed of a square metal. The lid member 40 is joined by seam welding through the element mounting member 10 and the joining metal layer 16 provided on the frame portion 12 of the element mounting member 10.

  Seam welding is a welding method in which a large current is passed through a welded portion to heat the welded portion and apply pressure.

  As shown in FIG. 3 and FIG. 5, by seam welding the element mounting member 10 and the lid member 40 via a metal layer 16 for bonding provided on the frame portion 12 of the element mounting member 10, The lid member 40 is heated and the joining metal layer 16 provided on the frame portion 12 of the element mounting member 10 is melted and joined. At this time, when the heat of the heated and melted metal portion cools, the metal contracts and warps in the longitudinal direction of the element mounting member 10. This warp pushes up the buffer portion 14c provided on the element mounting member 10, but passes through the center of the main surface facing the lid member side of the mounting portion 13 and is on the main surface of the substrate portion 11 of the recess. The surface acoustic wave from a position where the first center line CL1 parallel to the long side and the second center line CL2 passing through the center of the two long sides on the main surface of the substrate portion 11 of the recess intersect. The surface acoustic wave element 30 is less likely to be stressed by the buffer portion 14c because it faces the free end of the element 30 and is displaced by 16% of the long side dimension of the substrate portion 11 of the recess. When the buffer portion 14c is positioned on the free end side exceeding 16% of the long side dimension of the substrate portion 11 of the recess, the buffer portion 14c is pushed up by the warp in the longitudinal direction of the element mounting member 10, and the buffer A stress is applied to the surface acoustic wave element 30 in contact with the portion 14c.

  Further, the graph of FIG. 6C shows the difference between the frequency after seam welding (hereinafter referred to as frequency deviation) with the frequency before the seam welding of the SAW oscillator in the third embodiment as a reference, and the frequency on the vertical axis. It is a graph with a value and a measurement item on the horizontal axis. Further, for example, the upper limit frequency fluctuation value (hereinafter referred to as the upper limit value) on the graph is a value in which the difference from the frequency after seam welding is maximized in the positive direction with reference to the frequency before seam welding. Further, the lower limit frequency fluctuation value (hereinafter referred to as the lower limit value) on the graph is a value in which the difference from the frequency after seam welding is minimized from the upper limit value based on the frequency before seam welding. At this time, as shown in FIG. 6C, the frequency deviation is from the upper limit value + 6.0E × −06 to the lower limit value −2.5E × −06, and the conventional buffer portion position 214 in FIG. When compared with the upper limit value + 7.0E × −06, which is a frequency deviation at the lower limit value −19.0E × −06, the range of the upper limit value and the lower limit value in the third embodiment position is the same as that in the conventional buffer portion position. The width at the position of the third embodiment is smaller than the width between the upper limit value and the lower limit value. Therefore, the third embodiment can improve the productivity and reliability of the SAW oscillator.

  Thus, also in the position of the buffer part 14c which concerns on the 3rd Embodiment of this invention, there exists an effect equivalent to 1st Embodiment.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment. For example, in this embodiment, an integrated circuit element (IC) that controls the transmission output based on the vibration of the surface acoustic wave element is mounted. Moreover, although this invention demonstrated by seam welding, the same effect is acquired also by the sealing method which heats and joins junction parts, such as glass sealing and laser sealing, for example.

(Modification)
In the SAW oscillator 100 according to the first to third embodiments of the present invention, the buffer portion 14a passes through the center of the main surface facing the lid member side of the mounting portion 13, and the main portion of the substrate portion 11 of the concave portion. A position where a first center line CL1 parallel to one long side on the surface and a second center line CL2 passing through the center of the two long sides on the main surface of the substrate portion 11 of the recess intersect. 1 to the free end side of the surface acoustic wave element 30 up to a position shifted by 16% of the long side dimension of the substrate portion 11 of the concave portion. The same effect as the embodiment can be obtained.
That is, according to the SAW oscillator 100 of the present invention, the surface acoustic wave element 30 includes the element mounting member 10 and the lid member 40 via the bonding metal layer provided on the frame portion of the element mounting member 10. By sealing with seam welding, the lid member 40 is heated, and the metal layer for joining provided on the lid member 40 and the frame portion of the element mounting member 10 is melted and joined. At this time, when the heat of the heated and melted metal portion cools, the metal contracts and warps in the longitudinal direction of the element mounting member 10. This warping pushes up the buffer portion 14a provided in the element mounting member 10, but the position of the buffer portion passes through the center of the main surface facing the lid member side of the mounting portion 13 and the substrate portion of the concave portion. A position where a first center line CL1 parallel to one long side on the main surface and a second center line CL2 passing through the center of the two long sides on the main surface of the substrate portion of the recess intersect. To the free end side of the surface acoustic wave element 30 up to a position shifted by 16% of the long side dimension of the substrate portion of the recess, the buffer portion 14a makes it difficult to push up the surface acoustic wave element. be able to. Therefore, the SAW oscillator of the present invention can reduce the frequency deviation after seam welding, and can improve productivity and reliability.

100, 200 SAW oscillator 10, 210 Element mounting member 11, 211 Substrate part 12, 212 Frame part 13, 213 Mounting part 15, 215 Conductive adhesive 16, 216 Metal layer for bonding 20, 220 Integrated circuit element 30, 230 Surface acoustic wave device 40, 240 Lid member 14a First embodiment 14b Second embodiment 14c Third embodiment 214 Conventional position
CL1, CL2 center line

Claims (4)

  A flat substrate portion, a frame portion provided on one main surface of the substrate portion to form a recess, a mounting portion provided on the substrate portion inside the recess, and a substrate portion inside the recess An element mounting member including a buffer portion; a square surface acoustic wave device provided on the mounting portion via a conductive adhesive; an integrated circuit element mounted on the element mounting member; And the surface acoustic wave element is cantilevered on the substrate portion inside the recess, and the buffer portion passes through the center of the main surface facing the lid member side of the mounting portion, and the substrate of the recess A position where a first center line parallel to one long side on the principal surface of the portion intersects with a second center line passing through the center of the two long sides on the principal surface of the substrate portion of the recess. A SAW oscillator provided in the above.   A flat substrate portion, a frame portion provided on one main surface of the substrate portion to form a recess, a mounting portion provided on the substrate portion inside the recess, and a substrate portion inside the recess An element mounting member including a buffer portion; a square surface acoustic wave device provided on the mounting portion via a conductive adhesive; an integrated circuit element mounted on the element mounting member; And the surface acoustic wave element is cantilevered on the substrate portion inside the recess, and the buffer portion passes through the center of the main surface facing the lid member side of the mounting portion, and the substrate of the recess A position where a first center line parallel to one long side on the principal surface of the portion intersects with a second center line passing through the center of the two long sides on the principal surface of the substrate portion of the recess. More toward the free end side of the surface acoustic wave element, the longer side dimension of the substrate portion of the recess % Offset SAW oscillator according to claim 1, characterized in that in position.   A flat substrate portion, a frame portion provided on one main surface of the substrate portion to form a recess, a mounting portion provided on the substrate portion inside the recess, and a substrate portion inside the recess An element mounting member including a buffer portion; a square surface acoustic wave device provided on the mounting portion via a conductive adhesive; an integrated circuit element mounted on the element mounting member; And the surface acoustic wave element is cantilevered on the substrate portion inside the recess, and the buffer portion passes through the center of the main surface facing the lid member side of the mounting portion, and the substrate of the recess A position where a first center line parallel to one long side on the principal surface of the portion intersects with a second center line passing through the center of the two long sides on the principal surface of the substrate portion of the recess. More toward the free end side of the surface acoustic wave element, the longer side dimension of the substrate portion of the recess SAW oscillator according to claim 1, characterized in that 6% offset position.   A flat substrate portion, a frame portion provided on one main surface of the substrate portion to form a recess, a mounting portion provided on the substrate portion inside the recess, and a substrate portion inside the recess An element mounting member including a buffer portion; a square surface acoustic wave device provided on the mounting portion via a conductive adhesive; an integrated circuit element mounted on the element mounting member; And the surface acoustic wave element is cantilevered on the substrate portion inside the recess, and the buffer portion passes through the center of the main surface facing the lid member side of the mounting portion, and the substrate of the recess A position where a first center line parallel to one long side on the principal surface of the portion intersects with a second center line passing through the center of the two long sides on the principal surface of the substrate portion of the recess. 16% of the long side dimension of the substrate portion of the recess from the free end side of the surface acoustic wave element to SAW oscillator according to claim 1, characterized in that in the up position.

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