JP2015091100A - Surface acoustic wave device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface acoustic wave device in which the possibility that a signal output becomes unstable can be reduced by reducing an influence upon curing of an adhesive agent.SOLUTION: A surface acoustic wave device comprises: a package constituted of a flat plate portion and a frame portion provided along an outer peripheral edge of an upper surface of the flat plate portion; a pedestal portion being the upper surface of the flat plate portion and provided in the frame portion; a surface acoustic wave element constituted of a piezoelectric substrate, a comb-shaped electrode provided on an upper surface of the piezoelectric substrate and a connection terminal being the upper surface of the piezoelectric substrate and electrically connected to the comb-shaped electrode; an adhesive agent which is provided between a lower surface of the piezoelectric substrate and the pedestal portion, causes the lower surface of the piezoelectric substrate to adhere to the pedestal portion to fasten the surface acoustic wave element to the pedestal portion and to hold the surface acoustic wave element; a first groove portion which is an upper surface of the pedestal portion, extends to contours of the pedestal portion and is provided between a portion adhering thereto by the adhesive agent and the comb-shaped electrode as viewed in a plan view; and a lid member which adheres to an upper surface of the frame portion and hermetically seals the inside of the frame portion.

Description

  The present invention relates to a surface acoustic wave device used as a reference frequency source for electronic equipment, a frequency selector in a transmission circuit, or the like.

  As the surface acoustic wave device, there is a surface acoustic wave oscillator in which a surface acoustic wave element and an integrated circuit element having a function of an oscillation circuit for oscillating the surface acoustic wave element are mounted on a package. Therefore, in such a surface acoustic wave device, the surface acoustic wave element and the integrated circuit element are mounted in the same package. At this time, the surface acoustic wave element is mounted on the package with an adhesive.

  A surface acoustic wave element used in such a surface acoustic wave device includes at least a piezoelectric substrate and a pair of comb-shaped electrodes on the upper surface of the piezoelectric substrate. The pair of comb electrodes are provided on the upper surface of the piezoelectric substrate so as to face each other in a non-contact state. In addition, the pair of comb electrodes are configured such that when a voltage is applied, the upper surface of the piezoelectric substrate and the vicinity of the upper surface vibrate at a predetermined frequency due to the piezoelectric effect and the inverse piezoelectric effect. In addition, the surface acoustic wave element has a property that the frequency of vibration when a voltage is applied depends on the temperature of the piezoelectric substrate.

  Therefore, in the surface acoustic wave device, a pedestal portion is provided in the package in order to reduce frequency fluctuation due to heat generated in the integrated circuit element moving to the surface acoustic wave element. In such a surface acoustic wave device, a pedestal portion is provided inside a package, and the upper surface of the pedestal portion and the lower surface of the piezoelectric substrate of the surface acoustic wave element are bonded with an adhesive (for example, see Patent Document 1).

JP 2003-298388 A

  In the conventional surface acoustic wave device, the upper surface of the pedestal portion and the lower surface of the piezoelectric substrate are adhered by an adhesive, and the surface acoustic wave element is placed after the adhesive is applied to the upper surface of the pedestal portion. It is cured in a state. For this reason, in the conventional surface acoustic wave device, when the surface acoustic wave element is mounted, the adhesive spreads between the upper surface of the pedestal portion and the lower surface of the piezoelectric substrate, and adheres with the adhesive in plan view. The portion may overlap the comb electrode of the surface acoustic wave element. If the adhesive is cured in such a state, stress is applied to the portion of the piezoelectric substrate that is in contact with the adhesive due to the shrinkage of the adhesive, and the comb electrodes provided on the upper surface of the piezoelectric substrate are distorted. Therefore, there is a possibility that the frequency fluctuates with respect to a predetermined frequency and the output signal becomes unstable.

  An object of the present invention is to provide a surface acoustic wave device capable of reducing the instability of an output signal while suppressing the influence when the adhesive is cured.

  In order to solve the above-described problems, a surface acoustic wave device according to the present invention includes a package including a flat plate portion and a frame portion provided along the outer peripheral edge of the upper surface of the flat plate portion, and a flat plate portion. A pedestal portion provided in the frame portion on the upper surface, an electrode pad provided on the flat plate portion and provided in the frame portion, a comb electrode and a piezoelectric substrate provided on the piezoelectric substrate and the upper surface of the piezoelectric substrate A connection pattern having one end connected to the comb-shaped electrode and an electrode terminal connected to the upper end of the piezoelectric substrate and the other end of the connection pattern. A surface acoustic wave element that is electrically connected to the electrode terminal, an adhesive that adheres the lower surface of the piezoelectric substrate and the pedestal, and holds the surface acoustic wave element to the pedestal, and an upper surface of the pedestal And extended to the outer shape of the pedestal A first groove portion located between the portion bonded with the adhesive and the comb electrode in a plan view and a lid member that is joined to the upper surface of the frame portion and hermetically seals the inside of the frame portion. It is characterized by.

  In the surface acoustic wave device according to the embodiment of the present invention, the first groove portion extends to the outer shape of the pedestal portion, and is positioned between the comb-shaped electrode and the portion bonded with the adhesive in a plan view. Is provided. For this reason, in the surface acoustic wave device according to the embodiment of the present invention, the adhesive sandwiched between the lower surface of the piezoelectric substrate and the pedestal portion when the surface acoustic wave element is placed by applying an adhesive to the upper surface of the pedestal portion. Will flow into the first groove, and when cured as it is, it becomes possible to limit the portion where the lower surface of the piezoelectric substrate and the pedestal are bonded by the adhesive. Therefore, in the surface acoustic wave device according to the embodiment of the present invention, since the planar electrode and the portion bonded by the adhesive do not overlap each other, the adhesive is applied when the applied adhesive is cured. As a result of the shrinkage, a strain is generated in the piezoelectric substrate due to the stress applied to the piezoelectric substrate, and the strain generated in the comb electrode due to this strain can be reduced. For this reason, in the surface acoustic wave device according to the embodiment of the present invention, it is possible to reduce the output signal from becoming unstable while suppressing the fluctuation of the frequency due to the distortion of the comb electrode. Become.

1 is a plan view showing an example of a surface acoustic wave device according to an embodiment of the present invention in which a lid member is not provided. It is sectional drawing which shows the state of the cross section in AA of FIG. It is a perspective view which shows an example of the state of the package of the surface acoustic wave device which concerns on embodiment of this invention. It is a perspective view which shows an example of the state of the surface acoustic wave element of the surface acoustic wave device which concerns on embodiment of this invention. It is a perspective view which shows an example of the state of the package of the surface acoustic wave device which concerns on another Example.

  The surface acoustic wave device according to the embodiment of the present invention includes a package 110, a pedestal 120, a first groove 121, a surface acoustic wave element 130, as shown in FIGS. The adhesive 140 includes an integrated circuit element 150, a wire portion 160, a lid member 170, and a joining member 180. Such a surface acoustic wave device is used to output a reference signal used in an electronic apparatus.

  The package 110 includes a flat plate portion 110a, a frame portion 110b provided along the outer periphery of the upper surface of the flat plate portion 110a, and a step portion 111 provided on the flat plate portion 110a and in the frame portion 110b. ing. Therefore, the package 110 is formed with a recessed space surrounded by the upper surface of the flat plate portion 110a and the inner peripheral surface of the frame portion 110b. And two level | step-difference parts 111 are provided in the recessed part space.

  Here, according to the drawing, the surface of the flat plate portion 110a in contact with the frame portion 110b is the upper surface of the flat plate portion 110a, and the surface of the flat plate portion 110a opposite to the upper surface of the flat plate portion 110a is the lower surface of the flat plate portion 110a. The surface of the frame portion 110b in contact with the flat plate portion 110a is the lower surface of the frame portion 110b, and the surface of the frame portion 110b opposite to the lower surface of the frame portion 110b is the upper surface of the frame portion 110b.

  The flat plate portion 110a has a rectangular shape. The flat plate portion 110a functions as a mounting member for mounting the surface acoustic wave element 130, and a pedestal portion 120 for mounting the surface acoustic wave element 130 is provided on the upper surface of the flat plate portion 110a. The flat plate portion 110a functions as a mounting member for mounting the integrated circuit element 150. The flat plate portion 110a is provided with an external terminal 114 on the lower surface. The flat plate portion 110a is made of ceramics, for example.

  The frame portion 110b is disposed on the upper surface of the flat plate portion 110a, and is for forming a recessed space on the upper surface of the flat plate portion 110a. The frame portion 110b is made of, for example, ceramics and is formed integrally with the flat plate portion 110a.

  The step portion 111 is for forming an accommodation space for accommodating the integrated circuit element 150. The integrated circuit element 150 is mounted on the upper surface of the flat plate portion 110a in the storage space. The stepped portion 111 is composed of a first stepped portion 111a and a second stepped portion 111b, and is arranged on the upper surface of the flat plate portion 110a and in the frame portion 110b with a gap.

  The first step portion 111a is provided with an electrode pad 112 and a connection pad 113 on the upper surface. A connection pad 113 is provided on the upper surface of the second stepped portion 111b. The second stepped portion 111b is provided in a state spaced from the first stepped portion 111a. The first step portion 111a and the second step portion 111b are made of, for example, ceramics and are formed integrally with the flat plate portion 110a and the frame portion 110b.

  The first stepped portion 111a and the second stepped portion 111b have the same height as the upper surface of the connection terminal 151 of the integrated circuit element 150 when the integrated circuit element 150 is mounted on the flat plate portion 110a. Yes. For this reason, when the connection pad 113 and the connection terminal 151 are electrically connected by the wire portion 160, the bonding between the wire portion 160 and the connection pad 113 and the bonding between the wire portion 160 and the connection terminal 151 can be easily performed. It becomes possible. Moreover, the force applied to each from the wire part 160 can be equalized, and it becomes possible to ensure joint strength.

  The electrode pad 112 is for electrically connecting to the electrode terminal 133 of the surface acoustic wave element 130. The electrode pad 112 is provided on the upper surface of the first step portion 111 a and is electrically connected to the electrode terminal 133 of the surface acoustic wave element 130 by the wire portion 160.

  The connection pad 113 is for electrically connecting to the connection terminal 151. Therefore, the connection pads 113 correspond to the number of connection terminals 151. The connection pad 113 is provided on the upper surface of the step portion 111. For example, six connection pads 113 are provided, and three connection pads 113 are arranged side by side on the first step portion 111a and the second step portion 111b. Two of the connection pads 113 are electrically connected to the electrode pads 112 by wiring patterns. Four of the connection pads 113 are electrically connected to external terminals 114 provided on the lower surface of the flat plate portion 110a by internal wiring (not shown) provided in the stepped portion 111 and the flat plate portion 110a. Yes.

  The external terminal 114 is for mounting on a mounting board such as an electronic device. Further, for example, four external terminals 114 are provided, one at each of the four corners of the lower surface of the flat plate portion 110a, and predetermined four are provided by the internal wiring provided in the step portion 111 and the flat plate portion 110a. The two connection pads 113 are electrically connected.

  Such a package is provided with a base 120. The pedestal 120 is for mounting the surface acoustic wave element 130 on the package 110. The pedestal portion 120 is provided on the upper surface of the flat plate portion 110a, and is provided on the upper surface of the flat plate portion 110a and along the inner peripheral edge of the frame portion 110b.

  The pedestal portion 120 plays a role of reducing the influence of heat generated when the integrated circuit element 150 operates. The pedestal portion 120 is provided between the flat plate portion 110a and the adhesive 140 that holds the surface acoustic wave element 130 firmly. For this reason, the heat generated when the integrated circuit element 150 is operated first moves to the flat plate portion 110a, moves from the flat plate portion 110a to the adhesive 140 via the pedestal portion 120, and then the surface acoustic wave device 130. Will be moved to. Therefore, by providing the pedestal portion 120, the speed of heat transfer from the integrated circuit element 150 to the surface acoustic wave element 130 can be reduced as compared with the conventional case, and the influence of the heat of the integrated circuit element 150 can be reduced. .

  The first groove 121 is for reducing the adhesive 140 from overlapping the comb-shaped electrode 132a of the surface acoustic wave element 130 in plan view. The first groove portion 121 is provided on the upper surface of the pedestal portion 120 and extends to the outer periphery of the pedestal portion 120 in plan view. Thereby, when the adhesive 140 more than the capacity | capacitance of the 1st groove part 121 flows into the 1st groove part 121, since the adhesive agent 140 passes along the 1st groove part 121 and pushes to the outer periphery of the base part 120, the adhesive agent 140 becomes the 1st groove part. It is possible to suppress overflowing beyond 121 and to reduce the overlap between the comb-shaped electrode 132a and the adhesive 140 in a plan view.

  In the surface acoustic wave element 130, a comb electrode 132 a, a reflective electrode 132 b, an electrode terminal 133, and a connection pattern 134 are provided on the upper surface of the piezoelectric substrate 131. Further, the surface acoustic wave element 130 has a property that when the voltage is applied to the comb-shaped electrode 132a, the upper surface of the piezoelectric substrate 131 and the vicinity of the upper surface of the piezoelectric substrate 131 vibrate at a predetermined frequency. It can obtain mechanical vibration and plays a role of transmitting a reference signal of an electronic machine or the like.

  The piezoelectric substrate 131 is for vibrating the upper surface of the piezoelectric substrate 131 on which the comb-shaped electrode 132a is formed and the vicinity of the upper surface at a predetermined frequency when a voltage is applied to the comb-shaped electrode 132a. The piezoelectric substrate 131 uses a quartz member and has a rectangular flat plate shape. The piezoelectric substrate 131 has a bonding region 131a and a vibration region 131b.

  The bonding region 131 a is a region where the piezoelectric substrate 131 is bonded by the adhesive 140. Here, the bonding region 131a is located on the lower surface of the piezoelectric substrate 131 and on one end side. Specifically, as shown in FIG. 4, the bonding region 131a is located on the left side of the two-dot chain line between the comb electrode 132a and the reflective electrode 132b.

  The vibration region 131 b is a region where the comb-shaped electrode 132 a is formed on the upper surface of the piezoelectric substrate 131 and the piezoelectric substrate 131 is vibrated. Here, the vibration region 131b is located on the upper surface of the piezoelectric substrate 131 and in the vicinity of the upper surface, at the center of the upper surface of the piezoelectric substrate 131, near the center, and on the other end side. Specifically, as shown in FIG. 4, the vibration region 131b is located on the right side of the two-dot chain line between the comb electrode 132a and the reflective electrode 132b.

  The comb electrode 132 a is provided on the upper surface of the vibration region 131 b of the piezoelectric substrate 131 and is used to apply a voltage to the piezoelectric substrate 131. Further, the comb electrodes 132a are paired and are provided so as to face each other in a non-contact state.

  The reflective electrode 132b is for reflecting and amplifying the vibration generated by the voltage applied to the comb electrode 132a. For example, two reflective electrodes 132b are provided, one of the reflective electrodes 132b is provided on the upper surface of the vibration region 131b of the piezoelectric substrate 131, and the other of the reflective electrodes 132b is a bonding region 131a of the piezoelectric substrate 131. It is provided on the upper surface. That is, the reflective electrode 132b is provided so as to sandwich the comb-shaped electrode 132a in plan view.

  The electrode terminal 133 is used when a voltage is applied to the comb electrode 132a. In addition, the electrode terminal 133 is electrically connected to the comb electrode 132 a by the connection pattern 134. Therefore, it is possible to apply a voltage to the comb-shaped electrode 132a by applying a voltage to the connection terminal 133. The electrode terminal 133 is provided on the upper surface of the bonding region 131 a of the piezoelectric substrate 131.

  Further, the electrode terminal 133 has the same height as the electrode pad 112 provided in the first step portion 111a when the surface acoustic wave element 130 is mounted. For this reason, when the electrode terminal 133 and the electrode pad 112 are electrically connected by the wire portion 160, the bonding of the wire portion 160 and the electrode terminal 133 and the bonding of the wire portion 150 and the electrode pad 112 are performed by the surface acoustic wave element 130. As compared with the case where the is mounted obliquely, it can be easily performed. Moreover, the force applied to each from the wire part 160 can be made equal, and it becomes possible to ensure joint strength.

  The connection pattern 134 is for electrically connecting the comb-shaped electrode 132a and the electrode terminal 133. One end is connected to the comb-shaped electrode 132a and the other end is connected to the electrode terminal 133. It is provided on the upper surface of the piezoelectric substrate 131 in a state. By applying a voltage to the electrode terminal 133 by the connection pattern 134, it is possible to apply a voltage to the comb electrode 132a.

  The surface acoustic wave element 130 is mounted on the package 110 with the lower surface of the piezoelectric substrate 131 fixed and held by the pedestal 120 and the adhesive 140. At this time, the first groove 121 is provided at a position that does not overlap with the comb-shaped electrode 132a in plan view, and is provided between the portion bonded by the adhesive 140 and the comb-shaped electrode 132a. ing. That is, the first groove 121 is provided on the boundary between the bonding region 131a and the vibration region 131b of the piezoelectric substrate 131 in plan view. Thereby, in a plan view, the comb electrode 132a and the portion bonded by the adhesive 140 can be prevented from overlapping each other, so even if stress occurs when the adhesive 140 is cured, the comb electrode 132a is It is possible to reduce the occurrence of distortion.

  The adhesive 140 is for fixing and holding the pedestal part 120 and the surface acoustic wave element 130. The adhesive 140 is provided on one end side of the piezoelectric substrate 131 and between the lower surface of the bonding region 131 a of the piezoelectric substrate 131 and the upper surface of the pedestal portion 120. The adhesive 140 is a thermoplastic adhesive, for example, an epoxy adhesive. Such an adhesive 140 is first applied to the upper surface of the pedestal 120, and the applied adhesive 140 is placed between the lower surface of the piezoelectric substrate 131 and the upper surface of the pedestal 120, and is cured. Is provided. When sandwiched between the lower surface of the piezoelectric substrate 131 and the upper surface of the pedestal portion 120, the adhesive 140 spreads over the upper surface of the pedestal portion 120, and the portion to be bonded spreads, but flows to the first groove portion 121 when it extends to the first groove portion 121. It will be tough. For this reason, it can reduce that the part adhere | attached with the adhesive agent 140 by the 1st groove part 121 spreads to the vibration area | region 131b in planar view.

  The integrated circuit element 150 has a function of an oscillation circuit, and is used to oscillate the surface acoustic wave element 130. Further, the integrated circuit element 150 is mounted and fixedly held so as to be accommodated in an accommodating space formed between the first stepped portion 111a and the second stepped portion 111b, and is mounted on the package 110. The integrated circuit element 150 is provided with six connection terminals 151, and three connection terminals 151 are provided side by side on the upper surface of the integrated circuit element 150.

  The wire part 160 is for joining both ends and electrically connecting the joined parts. For the wire part 160, for example, a gold wire is used, and both ends thereof are joined by wire bonding joining.

  One end of the wire portion 160 is joined to the electrode terminal 133 of the surface acoustic wave element 130, and the other end is joined to the electrode pad 112 provided in the first step portion 111a. The pad 112 is electrically connected. At this time, since the height from the upper surface of the flat plate portion 110a to the electrode terminal 133 is the same as the height from the upper surface of the flat plate portion 110a to the electrode pad 112, both ends of the wire portion 160 are joined by wire bonding bonding. It becomes possible to join easily. Moreover, the force applied to each from the wire part 160 can be made equal, and joining strength can be ensured.

  Another wire portion 160 has one end joined to the connection terminal 151 of the integrated circuit element 150 and the other end joined to the connection pad 113, thereby electrically connecting the connection terminal 151 and the connection pad 113. Connected. At this time, since the vertical height from the upper surface of the flat plate portion 110a to the connection terminal 151 is the same as the vertical height from the upper surface of the flat plate portion 110a to the connection pad 113, both ends of the wire portion 160 are wired. When joining by bonding joining, it becomes possible to join easily. In addition, the force applied to each of the wire portions 160 can be made uniform, and the bonding strength can be ensured.

  The lid member 170 is joined by the frame portion 110b and the joining member 180 to hermetically seal the inside of the recessed space formed by the upper surface of the flat plate portion 110a and the inner peripheral surface of the frame portion 110b. The lid member 170 has a rectangular shape, and the size of the main surface is the same as that of the flat plate portion 110a. The lid member 170 is made of an alloy containing at least one of iron, nickel, and cobalt.

  The joining member 180 is for joining the lid member 170 and the frame part 110b to hermetically seal the inside of the space formed by the package 110 and the lid member 170. The joining member 180 is provided between the upper surface of the frame part 110b and the lid member 170.

  As the bonding member 180, an insulating member is used, and for example, glass is used. In the case of glass, it is a glass that melts at 300 to 400 degrees, and is made of, for example, low-melting glass or lead oxide glass containing vanadium. The glass is pasty with a binder and a solvent added, and is melted and then solidified to adhere to other members. The joining member 180 is provided by, for example, applying glass frit paste to the upper surface of the frame portion 110b or the lower surface of the lid member 170 by a screen printing method and drying. The composition of the lead oxide glass is composed of lead oxide, lead fluoride, titanium dioxide, niobium oxide, bismuth oxide, boron oxide, zinc oxide, ferric oxide, copper oxide and calcium oxide.

  In the surface acoustic wave device according to the embodiment of the present invention configured as described above, the first groove portion 121 extends to the outer shape of the pedestal portion 120 and is bonded to the adhesive 140 in plan view. It is provided so as to be positioned between the comb electrodes 132a. For this reason, in the surface acoustic wave device according to the embodiment of the present invention, when the surface acoustic wave element 130 is placed by applying the adhesive 140 on the upper surface of the pedestal portion 120, the lower surface of the piezoelectric substrate 131 and the pedestal portion 120 The sandwiched adhesive 140 flows into the first groove 121, and when it is cured as it is, it is possible to limit the portion where the lower surface of the piezoelectric substrate 131 and the pedestal 120 are bonded by the adhesive 140. Therefore, in the surface acoustic wave device according to the embodiment of the present invention, since the first groove 121 is provided between the bonded portion of the adhesive 140 and the comb-shaped electrode 132a in plan view, the applied adhesive 140 is applied. When the adhesive 140 contracts when the adhesive 140 is cured, stress is generated in the piezoelectric substrate 131, and distortion in the comb-shaped electrode 132a provided on the piezoelectric substrate 131 can be reduced. On the other hand, it is possible to reduce the instability of the output signal due to the fluctuation of the frequency.

  In the surface acoustic wave device according to the embodiment of the present invention, the first groove 121 provided in the pedestal portion 120 is provided so as to extend to the outer shape of the pedestal portion 120. For this reason, when the adhesive 140 is applied too much on the upper surface of the pedestal portion 120, the adhesive 140 flows through the first groove portion 121 to the outer periphery of the pedestal portion 120. That is, when the first groove 121 extends to the outer shape of the pedestal 120, the adhesive 140 overflows beyond the first groove 121, and a portion bonded by the adhesive 140 in a plan view is a comb-shaped electrode. Overlapping with 132a can be reduced.

  In the surface acoustic wave device according to the embodiment of the present invention, the integrated circuit element 150 is mounted on the upper surface of the flat plate portion 110a, and the pedestal portion 120 provided with the surface acoustic wave element 130 on the upper surface of the flat plate portion 110a. Are fixedly held by an adhesive 140. Therefore, in the surface acoustic wave device according to the embodiment of the present invention, when the integrated circuit element 150 operates, the heat generated in the integrated circuit element 150 moves to the flat plate portion 110a and then moves to the pedestal portion 120. Furthermore, it finally moves from the pedestal 120 to the surface acoustic wave element 130 via the adhesive 140. Therefore, in the surface acoustic wave device according to the embodiment of the present invention, the time required for the heat of the integrated circuit element 150 to move to the surface acoustic wave element 130 can be delayed as compared with the surface acoustic wave device not provided with the pedestal 120. Therefore, frequency fluctuation due to heat generated in the integrated circuit element 150 moving to the surface acoustic wave element 130 can be reduced.

  In the surface acoustic wave device according to the embodiment of the present invention, the surface acoustic wave element 130 is fixedly held by the adhesive 140 on the upper surface of the pedestal portion 120. At this time, the piezoelectric substrate 131 of the surface acoustic wave element 130 is placed so that it is as parallel as possible to the upper surface of the flat plate portion 110a. For this reason, compared with the case where the surface acoustic wave element 130 is mounted obliquely, when the connection terminal 133 and the electrode pad 111 are electrically connected by the wire portion 160, the bonding is performed by wire bonding bonding. Can be easily. Moreover, since it can join in the stable state, it becomes possible to maintain joining strength.

(Modification)
Hereinafter, a surface acoustic wave device according to a modification of the present embodiment will be described. Note that, in the surface acoustic wave device according to the present embodiment, portions similar to those of the surface acoustic wave device described above are given the same reference numerals, and description thereof is omitted as appropriate. As shown in FIG. 5, the surface acoustic wave device according to the modification of the present embodiment is implemented in that the first groove portion 221, the second groove portion 222, and the third groove portion 223 are provided in the pedestal portion 220. Different from form.

  The pedestal portion 220 is for mounting the surface acoustic wave element 130 on the package 110. The pedestal portion 220 is provided on the upper surface of the flat plate portion 110a, and is provided on the upper surface of the flat plate portion 110a and along the inner peripheral edge of the frame portion 110b.

  The pedestal 220 plays a role of reducing the influence of heat generated when the integrated circuit element 150 operates. The pedestal portion 220 is provided between the flat plate portion 110a and the adhesive 140 that holds the surface acoustic wave element 130 firmly. For this reason, the heat generated when the integrated circuit element 150 operates first moves to the flat plate portion 110a, then moves from the flat plate portion 110a to the adhesive 140 via the pedestal portion 220, and then the surface acoustic wave device 130. Will be moved to. Therefore, by providing the pedestal portion 220, the speed of heat transfer from the integrated circuit element 150 to the surface acoustic wave element 130 can be reduced as compared with the conventional case, and the influence of the heat of the integrated circuit element 150 can be reduced. .

  The first groove portion 221 is for preventing the comb-shaped electrode 132a and the adhesive portion due to the adhesive 140 from overlapping each other in plan view, and between the comb-shaped electrode 132a and the adhesive portion due to the adhesive 140. Is provided. That is, the first groove 221 is located at the boundary between the bonding region 131a and the vibration region 131b of the piezoelectric substrate 131. Further, the first groove portion 221 extends to the outer shape of the pedestal portion 220 in plan view. For this reason, even if the amount of the adhesive 140 exceeding the capacity of the first groove 221 flows, the adhesive 140 is pushed out to the outer shape of the pedestal 220, so that the adhesive 140 overflows beyond the first groove 221 and the adhesive 140 is combed in plan view. Overlap with the shaped electrode 132a can be reduced.

  The second groove portion 222 rises up to the upper surface of the piezoelectric substrate 131 when the applied adhesive 140 is sandwiched between the upper surface of the pedestal portion 220 and the surface acoustic wave element 130, and the adhesive 140 is applied to the upper surface of the piezoelectric substrate 131. This is to prevent adhesion. The second groove 222 is located below the bonding region 131 a of the piezoelectric substrate 131. Further, the second groove portion 222 is provided along one side of the pedestal portion 220 while being connected to the first groove portion 221 in a plan view. The second groove part 222 is provided so as to be orthogonal to the first groove part 221 in a plan view, for example. Further, the second groove portion 222 extends to the outer shape of the pedestal portion 220 in the direction opposite to the comb-shaped electrode 132a in plan view. For this reason, even if the adhesive 140 exceeding the capacity of the second groove portion 222 flows, the adhesive 140 is pushed out to the outer shape of the pedestal portion 220, so that the adhesive 140 overflows beyond the second groove portion 222, and the adhesive 140 flows onto the upper surface of the piezoelectric substrate 131. As a result, the adhesion to the upper surface of the piezoelectric substrate 131 can be reduced.

  The third groove 223 rises up to the upper surface of the piezoelectric substrate 131 when the applied adhesive 140 is sandwiched between the upper surface of the pedestal portion 220 and the surface acoustic wave element 130, and the adhesive 140 is applied to the upper surface of the piezoelectric substrate 131. This is to prevent adhesion. The third groove 223 is located on the lower surface of the bonding region 131 a of the piezoelectric substrate 131. The third groove 223 is provided in a state of being spaced apart from the second groove 222 along the second groove 222 in a plan view while being connected to the first groove 221. The third groove part 223 is provided so as to be orthogonal to the first groove part 221 in plan view, for example. The third groove portion 223 extends to the outer shape of the pedestal portion 220 in the direction opposite to the comb-shaped electrode 132a in plan view. The third groove 223 is provided so as to be parallel to the second groove 222 in plan view. For this reason, even if the adhesive 140 more than the capacity | capacitance of the 3rd groove part 223 flows in with the 2nd groove part 222 provided facing the one side of the base part 220 provided along the said 3rd groove part 223. Since it pushes out to the external shape of the base part 220, it can further reduce that the adhesive agent 140 overflows over the 3rd groove part 223, and the adhesive agent 140 crawls up to the upper surface of the piezoelectric substrate 131, and adheres to the upper surface of the piezoelectric substrate 131. .

  Therefore, in the surface acoustic wave device according to the modification of the present embodiment, a portion surrounded by the first groove portion 221, the second groove portion 222, the third groove portion 223, and the outer shape of the pedestal portion 220 in the plan view is the adhesive 140. It becomes a part to be adhered by. That is, in the surface acoustic wave device according to the modified example of the present embodiment, the first groove portion 221, the second groove portion 222, and the third groove portion 223 cause the portion bonded by the adhesive 140 to the vibration region 131b in plan view. Spreading can be reduced. As a result, in the surface acoustic wave device according to the modified example of the present embodiment, it is possible to make the bonding area between the surface acoustic wave element 130 and the pedestal portion 220 constant, thereby reducing variations between products, and producing It becomes possible to improve the property.

110: Package 110a ... Flat plate portion 110b ... Frame portion 111 ... Stepped portion 112 ... Electrode pads 120, 220 ... Base portions 121, 221 ... First groove portion 222 ... Second groove 223 ... Third groove 130 ... Surface acoustic wave element 131 ... Piezoelectric substrate 132a ... Comb electrode 133 ... Electrode terminal 134 ... Connection pattern 140 ... Adhesive 150 ... Integrated circuit element 170 ... Cover member

Claims (2)

A package composed of a flat plate portion and a frame portion provided along the outer peripheral edge of the upper surface of the flat plate portion;
A pedestal portion provided in the frame portion on the upper surface of the flat plate portion;
An electrode pad provided on the flat plate portion and in the frame portion;
A piezoelectric substrate, a comb electrode provided on the top surface of the piezoelectric substrate, a top surface of the piezoelectric substrate, a connection pattern having one end connected to the comb electrode, and a top surface of the piezoelectric substrate, A surface acoustic wave element comprising an electrode terminal to which the other end of the connection pattern is connected, and the electrode pad and the electrode terminal being electrically connected;
An adhesive that adheres the lower surface of the piezoelectric substrate and the pedestal portion, and holds the surface acoustic wave element to the pedestal portion;
A first groove portion that is an upper surface of the pedestal portion and extends to the outer shape of the pedestal portion, and is positioned between the comb-shaped electrode and the portion bonded by the adhesive in plan view;
A lid member that is bonded to the upper surface of the frame portion and hermetically seals the inside of the frame portion;
A surface acoustic wave device comprising: The surface acoustic wave device according to claim 1,
In plan view, provided along one side of the pedestal portion, a second groove portion having one end connected to the first groove portion and the other end extending to the outer shape of the pedestal portion;
In plan view, provided along one side facing the one side, a third groove part having one end connected to the first groove part and the other end extending to the outer shape of the pedestal part;
Have
The surface acoustic wave device, wherein the adhesive is located in a portion surrounded by the first groove portion, the second groove portion, and the third groove portion in plan view.

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