JP4545004B2 - Piezoelectric oscillator - Google Patents

Description

  The present invention relates to a piezoelectric oscillator used in an electronic device such as a portable communication device.

  Conventionally, a piezoelectric oscillator such as a temperature-compensated crystal oscillator (TCXO) has been widely used as a timing device incorporated in an electronic device such as a portable communication device.

  As such a conventional piezoelectric oscillator, for example, as shown in FIG. 10, a first container body 21 in which a crystal vibration element (piezoelectric vibration element) is accommodated in a recess opened upward, and a plurality of external terminals are provided on the lower surface. There is a known structure in which a structure is mounted and fixed on a second container body 23 that houses an oscillation IC 22 for controlling the oscillation output of a crystal resonator element in a recess that is open at the top (for example, , See Patent Document 1).

  A plurality of connection electrodes 24 are provided around the opening of the second container body 23, and connection electrodes (not shown) corresponding to the connection electrodes 24 on the lower surface of the first container body 21. The first container body 21 is fixed on the second container body 23 by joining the two together via a brazing material such as solder.

  After the assembly is completed, the opening of the first container body 21 is closed by joining a metal lid 25 by a well-known seam welding (resistance welding) or the like. The receiving area is hermetically sealed.

In addition, as a method of manufacturing such a conventional piezoelectric oscillator, usually, only the first container body 21 and the second container body 23 are manufactured by the “multiple picking” technique, and the individual pieces obtained after the division are obtained. The crystal resonator element and the oscillation IC 22 are individually mounted on the (first container body 21 and second container body 23), and both are joined to assemble the product.
JP-A-10-98151

  However, the above-described conventional piezoelectric oscillator is assembled by vertically stacking the first container body 21 in which the crystal resonator element is accommodated and the second container body 23 in which the oscillation IC 22 is accommodated. The overall structure will become taller. Therefore, it has a drawback that it is difficult to reduce the thickness (thinner) of the piezoelectric oscillator.

  Further, in the above-described manufacturing method, when the second container body 23 is divided into individual pieces and the oscillation IC 22 and the first container body 21 are mounted on the second container body 23, the operation is completed. In the meantime, it is necessary to hold the second container body 23 individually with a carrier member or the like, and the assembly work is complicated, and additional manufacturing equipment for the carrier member or the like is required. There was a disadvantage that the productivity of the temperature compensated crystal oscillator was lowered.

  The present invention has been devised in view of the above-described drawbacks, and an object thereof is to provide a piezoelectric oscillator having a structure optimal for reducing the height.

In the piezoelectric oscillator of the present invention, the upper surface of the support substrate and the lower surface of the oscillation IC are joined with a sealing member so as to form a sealed space therebetween, and the oscillation IC and the electrical circuit are electrically connected in the sealed space. In the piezoelectric oscillator that accommodates the piezoelectric vibration elements connected to each other, the upper surface of the support substrate and the lower surface of the oscillation IC are planar, and are in contact with the support substrate and the oscillation IC. with suppressing the spacer member varies in the sealed space is provided, the connection pad before Symbol supporting substrate at the inside of the sealed space and the electrode pads on the oscillation IC via a conductive bonding material connected, the piezoelectric vibrating element is being mounted on the supporting substrate or the oscillation IC via a conductive adhesive, it characterized that you have to use the conductive adhesive as the spacer member.

  The piezoelectric vibration element is mounted on the lower surface of the oscillation IC.

  The sealing member is made of a brazing material.

  The sealing member and the conductive bonding material are made of the same metal material.

  The sealing member is formed of a metal material, and the sealing member is electrically connected to a ground terminal on the lower surface of the support substrate.

  A shield layer is deposited on the upper surface of the oscillation IC.

  An end portion of the shield layer is extended to the sealing member along a side surface of the oscillation IC.

  A radio wave absorber layer is deposited on the upper surface of the oscillation IC.

  The support substrate is formed of a ceramic material, the sealing member is formed of a metal material, and an end portion of the radio wave absorber layer extends to the support substrate and / or the sealing member along a side surface of the oscillation IC. It was made to be characterized.

According to the piezoelectric oscillator of the present invention, the upper surface of the support substrate and the lower surface of the oscillation IC are planar, and the accommodation area of the piezoelectric vibration element disposed on the support substrate is closed with the oscillation IC. Compared to the example, the entire structure can be formed thin, and the piezoelectric oscillator can be reduced in height.

Further, in the inside of the sealed space, since it was set to the connection pads on the supporting substrate and the electrode pads on the oscillation IC is connected via a conductive bonding material, between the oscillation IC- support substrate Since the sealing state can be easily confirmed by visual inspection or the like, the workability required for the inspection of the product is improved. In addition, a spacer member is provided that is brought into contact with the support substrate and the oscillation IC to suppress variation in the sealing space, and the piezoelectric vibration element is mounted on the support substrate or the oscillation IC via a conductive adhesive. It has been, a conductive adhesive since you are used as a spacer member, separately without the need of providing a region for forming the spacer member to the supporting substrate and the oscillation IC, the sealing member or the conductive during the reflow process It is possible to suppress the bonding material from being softened and the sealing space from fluctuating.

  Furthermore, if the piezoelectric vibration element is mounted on the lower surface of the oscillation IC, the vibration electrode of the piezoelectric vibration element is directly connected to the electrode pad of the oscillation IC, so the oscillation IC is mounted on the support substrate side. Compared with the case where the piezoelectric vibration element and the electronic circuit of the oscillation IC are connected, the length of the wiring is shortened to effectively prevent the generation of capacitance due to the wiring resistance, and the oscillation characteristics close to the design value. Can be obtained.

  Furthermore, by forming the sealing member with a brazing material, the bonding strength between the support substrate and the oscillation IC can be increased, and the sealing portion or connection caused by the thermal stress between the support substrate and the oscillation IC can be increased. It becomes possible to effectively prevent the breakage of the portion and improve the productivity and reliability of the piezoelectric oscillator. In particular, if the sealing member and the conductive bonding material are formed of the same brazing material, both can be formed in the same process and then brazed in the same process, which increases the productivity of the piezoelectric oscillator. Can be improved.

  Furthermore, the sealing member is formed of a metal material, and the sealing member is electrically connected to the ground terminal on the lower surface of the support substrate, so that the piezoelectric vibration element is accommodated when the piezoelectric oscillator is used. Since the sealing space and the circuit forming surface of the oscillation IC (the lower surface of the oscillation IC) are surrounded by the sealing member held at the ground potential, the external space is about to enter the sealing space. A part of noise is shielded by the sealing member, and the oscillation IC and the piezoelectric vibration element in the sealing space can be operated more stably. The sealing member is electrically connected to the ground terminal via a wiring pattern formed between the plurality of insulating layers constituting the support substrate, a via hole conductor formed so as to penetrate the insulating layer, and the like. It ’s fine.

  Furthermore, if a shield layer is deposited on the upper surface of the oscillation IC, noise from the outside can be well shielded by the shield layer, thereby maintaining high operational reliability of the piezoelectric oscillator. . In particular, in this case, if the end of the shield layer extends to the sealing member along the side surface of the oscillation IC, noise from the outside can be better shielded. The operation reliability can be kept high.

  Furthermore, if a radio wave absorber is attached to the upper surface of the oscillation IC, noise from the outside is satisfactorily absorbed by the radio wave absorber when the piezoelectric oscillator is used, and the noise from the outside is sealed. It is possible to effectively prevent the user from entering the inside. Therefore, even in such a case, the piezoelectric vibration element and the oscillation IC can be stably operated when the piezoelectric oscillator is used. In particular, if the support substrate is made of a ceramic material, the sealing member is made of a metal material, and the end of the radio wave absorber layer extends to the support substrate and / or the sealing member along the side surface of the oscillation IC. The heat energy generated by absorbing noise from the outside can be dissipated well to the outside through the support substrate, and various kinds of heat energy caused by the accumulation inside the piezoelectric oscillator This inconvenience can be effectively prevented.

  Furthermore, if the oscillation IC and the support substrate are set to be substantially the same in plan view, the impact applied to the piezoelectric oscillator from the side surface can be reduced by both the oscillation IC and the support substrate. It becomes.

Hereinafter, an embodiment of a piezoelectric oscillator of the present invention will be described in detail with reference to the accompanying drawings.

Figure 1 is an exploded perspective view showing an example of applying the pressure electrostatic oscillator as a reference example the crystal oscillator of the surface mount, FIG. 2 is a sectional view of the crystal oscillator of FIG. 1, FIG. 3 is used in the crystal oscillator of FIG. 1 FIG. 4 is a plan view of the supporting substrate viewed from above, and FIG. 4 is a plan view of the oscillation IC used in the crystal oscillator of FIG. 1 viewed from below.

  The crystal oscillators shown in these drawings are generally composed of a support substrate 1, an oscillation IC 2, and a crystal resonator element 3 as a piezoelectric resonator element. The IC 2 and the support substrate 1 are set to be substantially the same in plan view.

  The support substrate 1 is formed, for example, by laminating a frame-like insulating layer 1b on a flat insulating layer 1a, and has a structure having a recess 6 in the central region on the upper surface side. The support substrate 1 has a predetermined wiring conductor formed on the surface or between adjacent insulating layers, and a via-hole conductor 4 or the like for electrically connecting the wiring conductors is embedded therein. A plurality of external terminal electrodes 5 are provided on the lower surface of the support substrate 1. In the present embodiment, four external terminal electrodes 5 are provided at the four corners of the lower surface of the support substrate 1, and function as a power supply voltage terminal, a ground terminal, an oscillation output terminal, and an oscillation control terminal, respectively. These external terminal electrodes 5 are electrically connected to the circuit wiring of the external electric circuit by soldering or the like when the crystal oscillator is mounted on an external electric circuit such as a mother board (not shown).

  The insulating layers 1a and 1b are made of, for example, a ceramic material such as glass-ceramic or alumina ceramic, or an organic material such as resin.

  In addition, the crystal resonator element 3 is accommodated in the recess 6 provided on the upper surface side of the support substrate 1. In this embodiment, the crystal resonator element 3 is housed in the recess 6 in a state of being mounted on the lower surface of the oscillation IC 2, and the corresponding vibration electrode of the crystal resonator element 3 is mounted on the mounting pad provided on the lower surface of the oscillation IC 2. It is electrically connected via a conductive adhesive.

  Furthermore, as shown in FIG. 3, a plurality of connection pads 10 are attached to the upper surface of the frame-like insulating layer 1b, and a substrate-side sealing conductor 12 is formed on the outer peripheral side.

  When the support substrate 1 is made of alumina ceramic, for example, an appropriate organic solvent or the like is added to and mixed with the raw material powder of alumina ceramic, and then formed into a predetermined shape by a conventionally known doctor blade method or the like. A ceramic green sheet is obtained, and a conductive paste serving as a wiring conductor is applied to a surface of the ceramic green sheet in a predetermined pattern, a plurality of these are laminated, press-molded, and then fired at a high temperature. The recess 6 is formed by forming a rectangular through-hole in the central region of the ceramic green sheet disposed in the upper region of the ceramic green sheet used for manufacturing the support substrate 1.

  On the support substrate 1, a flip-chip type oscillation IC 2 is arranged. A crystal resonator element 3 is mounted on the lower surface of the oscillation IC 2, and the crystal resonator element 3 is formed by attaching and forming a pair of vibration electrodes on both main surfaces of a crystal piece cut along a predetermined crystal axis. Thus, when an externally varying voltage is applied to the crystal piece via a pair of vibrating electrodes, thickness-shear vibration is caused at a predetermined frequency.

  The crystal resonator element 3 is mounted on the lower surface of the oscillation IC 2 by electrically connecting a pair of vibration electrodes to a corresponding mounting pad 15 provided on the lower surface of the oscillation IC 2 via a conductive adhesive. It arrange | positions in the recessed part 6 of the support substrate 1 in this state.

If the crystal resonator element 3 is mounted on the lower surface of the oscillation IC 2 in this way, the vibration electrode of the crystal resonator element 3 is directly connected to the mounting pad 15 of the oscillation IC 2. Compared with mounting on the support substrate 1 side, the length of the wiring connecting the crystal resonator element 3 and the electronic circuit of the oscillation IC 2 is remarkably shortened, and it is possible to effectively prevent the generation of capacitance due to the wiring resistance. it can. Thereby, an oscillation characteristic close to the design value can be obtained.

  On the lower surface of the oscillation IC 2, as shown in FIG. 4, a crystal resonator element 3 is mounted in the central region, and a plurality of electronic circuits and mounting pads 15 that are electrically connected to the periphery of the oscillation circuit 2. A number of electrode pads 9 are formed. The IC-side sealing conductor 13 is provided so as to surround the crystal resonator element 3 and to be formed substantially in the same shape as the substrate-side sealing conductor 12 outside the mounting pad 15. .

  A shield layer 16 is attached to the upper surface of the oscillation IC 2. The shield layer 16 can shield external noise satisfactorily and maintain high operational reliability of the crystal oscillator. As a material of such a shield layer 16, for example, an epoxy resin containing metal particles such as Ag is used. As shown in FIG. 8, if the end portion of the shield layer 16 is extended to the sealing member 11 along the side surface of the oscillation IC 2, noise from the outside can be shielded better, thereby The operation reliability of the piezoelectric oscillator can be maintained high.

  The oscillation IC 2 stores temperature compensation data for compensating the temperature characteristics of the temperature sensing element (thermistor) for detecting the ambient temperature state and the crystal oscillation element 3 on the lower surface of the substrate made of single crystal silicon or the like, and the temperature compensation. An electronic circuit such as a temperature compensation circuit that corrects the vibration characteristics of the crystal resonator element 3 according to a temperature change based on data and an oscillation circuit that is connected to the temperature compensation circuit and generates a predetermined oscillation output is provided. The oscillation output generated by the oscillation circuit described above is output to the outside and then used as a reference signal such as a clock signal.

  Then, the IC-side sealing conductor 13 formed on the lower surface of the oscillation IC 2 and the substrate-side sealing conductor 12 formed on the upper surface of the support substrate 1 are connected via the sealing member 8 to oscillate. The storage space of the crystal resonator element 3 surrounded by the sealing space 11 provided between the IC 2 for use and the support substrate 1, that is, the lower surface of the oscillation IC 2 and the inner surface of the recess 6 is hermetically sealed.

  In addition, a conductive bonding material 7 is disposed on the inner side of the sealing member 8. The conductive bonding material 7 is formed on the upper surface of the insulating layer 1 b and the electrode pad 9 formed on the lower surface of the oscillation IC 2. The connection pad 10 is electrically and mechanically connected.

  In this way, by configuring the accommodation area of the crystal resonator element 3 disposed on the support substrate 1 with the oscillation IC 2, the overall structure can be formed thinner than in the conventional example. It becomes possible to use for low profile.

  In addition, the sealing member 8 that connects the IC-side sealing conductor 13 formed on the lower surface of the oscillation IC 2 and the substrate-side sealing conductor 12 formed on the upper surface of the support substrate 1 is connected to the conductive bonding material 7. In addition, since the sealing state between the oscillation IC and the support substrate can be confirmed very easily by visual observation or the like, the workability for product inspection and the like is improved.

  The oscillation IC 2 is obtained by slicing a single crystal silicon ingot to a predetermined thickness to obtain a silicon wafer, and adopting a well-known semiconductor manufacturing technique on one main surface thereof, an electronic circuit such as an oscillation circuit, electrode pads, bonding It is obtained by dividing an IC wafer manufactured by forming a conductor layer for use.

  Moreover, as the conductive bonding material 7 and the sealing member 8 described above, for example, a brazing material made of metal such as Au, Au—Sn alloy, or solder is preferably used. The sealing member 8 is a wiring conductor of the support substrate 1. Etc., and electrically connected to the ground terminal 5 on the lower surface of the support substrate. If the sealing member 8 is electrically connected to the ground terminal 5 in this way, when the crystal oscillator is used, the sealing space 11 in which the crystal resonator element 3 is accommodated and the circuit forming surface (oscillation IC 2). Since the lower surface of the IC 2 is surrounded by the sealing member 8 held at the ground potential GND, a part of the external noise that tries to enter the sealing space 11 is removed by the sealing member 8. Therefore, the oscillation IC 2 and the crystal resonator element 3 in the sealed space 11 can be operated more stably.

In the crystal oscillator as described above, the crystal resonator element 3 is first mounted on the bottom surface of the oscillation IC 2, and then the crystal resonator element 3 having the oscillator IC 2 mounted on the bottom surface is disposed in the recess 6 of the support substrate 1. Then, it is placed on the support substrate 1 via the conductive bonding material 7 and the sealing member 8, and thereafter, this is maintained in an inert gas atmosphere such as N ₂ gas or Ar gas or at a predetermined degree of vacuum. Then, heat treatment is performed in a vacuum, and the conductive bonding material 7 and the sealing member 8 are bonded to the upper surface of the support substrate 1 and the lower surface of the oscillation IC 2, respectively.

  Here, if the sealing member 8 is formed of a brazing material, the bonding strength between the support substrate 1 and the oscillation IC 2 is increased. Therefore, the sealing portion caused by the thermal stress between the support substrate 1 and the oscillation IC 2 is obtained. As a result, breakage of the connection portion and the like can be effectively prevented, and the productivity and reliability of the crystal oscillator can be improved. In this case, if the sealing member 8 and the conductive bonding material 7 are formed of the same brazing material, both can be formed in the same process and brazed in the same process. There is also an advantage that the productivity of the oscillator can be maintained high.

  In the assembly process described above, the oscillation IC 2 is bonded to the support substrate 1 in an inert gas atmosphere by filling the sealing space 11 in which the crystal resonator element 3 is accommodated with an inert gas. This is to stabilize the electrical characteristics of the crystal resonator element 3 and the like. Further, when the oscillation IC 2 is joined in a vacuum, the electrical characteristics of the crystal resonator element 3 can be stabilized and the crystal impedance of the crystal resonator element 3 can be kept low.

  When solder is used as the conductive bonding material 7 or the sealing member 8, it is preferable to employ a conventionally known hydrogen reduction method in order to remove the oxide film satisfactorily without using contaminants such as flux. .

  Finally, the probe needle of the temperature compensation data writing device is applied to a writing control terminal (not shown) provided on the outer surface of the support substrate 1, and the temperature characteristic of the crystal resonator element 3 measured in advance is determined. The temperature compensation data is stored in the memory of the oscillation IC 2 by writing the temperature compensation data.

  Thus, the above-described crystal oscillator is mounted on an external wiring board such as a mother board by soldering or the like, and the resonance frequency of the crystal resonator element 3 is corrected while correcting the oscillation output by the temperature compensation circuit of the oscillation IC 2 according to the temperature state. It functions as a crystal oscillator by outputting a predetermined oscillation signal according to the above.

  Next, a manufacturing method of the above-described crystal oscillator (piezoelectric oscillator) will be described with reference to FIGS.

(Process A)
First, an IC wafer 18 as shown in FIG. 5A is prepared.

  The IC wafer 18 is obtained by slicing a single crystal silicon ingot to a predetermined thickness to obtain a silicon wafer, and adopting a well-known semiconductor manufacturing technique on one main surface thereof, an electronic circuit such as an oscillation circuit, an electrode pad, and a bonding conductor It is manufactured by forming a layer or the like.

  Then, one crystal resonator element 3 is mounted on each oscillation IC 2 of the IC wafer 18, and a vibration electrode (not shown) of the crystal resonator element 3 and a mounting pad on the upper surface of the IC wafer 18 are interposed via a conductive adhesive. Connected electrically and mechanically.

  In the present embodiment, a predetermined separation area is provided between the oscillation ICs 2 arranged vertically and horizontally (in a matrix).

(Process B)
Next, a mother board 17 as shown in FIG.

  The mother substrate 17 is formed by laminating three layers of the same flat plate substrate made of the same material as the above-described support substrate 1, that is, a ceramic material such as glass-ceramic and alumina ceramic, and further in a matrix form made of a ceramic material, It is formed by laminating substrates having a large number of rectangular holes arranged in a matrix of vertical m columns × horizontal n rows (m and n are natural numbers of 2 or more). In the substrate region 19, a pair of connection pads on the bottom surface of the cavity and a bonding conductor layer surrounding the periphery of the opening are deposited and formed on the upper surface side, and external terminals such as input / output terminals and ground terminals are formed on the lower surface side. Deposited and formed.

  Such a mother substrate 17 becomes, for example, a connection pad, an external terminal, a conductor pattern, etc. on the surface of a ceramic green sheet obtained by adding and mixing a suitable organic solvent or the like to a ceramic material powder made of alumina ceramic or the like. The conductor paste is printed and applied in a predetermined pattern, and a plurality of the pastes are laminated and press-molded, and then fired at a high temperature.

  Then, as shown in FIG. 5C, the sealing member 8 that hermetically seals the crystal resonator element 3 on the mother substrate 17 having the plurality of substrate regions 19 is mounted on the IC wafer 18 on which the crystal resonator element 3 is mounted. The collective piezoelectric oscillator is formed by bonding via the.

Here, the crystal resonator element 3 is configured such that a pair of vibration electrodes is electrically connected to a corresponding mounting pad 15 provided on the lower surface of each oscillation IC 2 of the IC wafer 18 through a conductive adhesive, thereby causing the oscillation IC 2. is mounted in the lower surface, it remains thus mounted state, is arranged in the recess 6 that are provided at each support substrate of the mother substrate 17.

  Further, a plurality of conductive materials for electrically connecting the electronic circuit of the oscillation IC 2 and the connection pads of the substrate region 19 are provided between the oscillation ICs 2 of the IC wafer 18 and the substrate regions 19 of the mother substrate 17. In the bonding material 7, an annular sealing member 8 is interposed outside the conductive bonding material 7, and the sealing member 8 is a sealing space provided between the oscillation IC 2 and the substrate region 19. 11. More specifically, hermetic sealing is performed by surrounding the storage area of the crystal resonator element 3 surrounded by the lower surface of the oscillation IC 2, the inner surface of the recess 6, and the like.

(Process C)
Then, as shown in FIG. 5-4, the mother substrate 17 and the IC wafer 18 of the obtained collective piezoelectric oscillator are cut with a dicer or the like along the outer periphery of each substrate region 19 and the oscillation IC 2. A piezoelectric oscillator can be obtained.

  According to the manufacturing method as described above, since the IC wafer 18 functions as a carrier member in the manufacturing process, a separate carrier member is prepared, and the individual oscillation ICs 2 obtained by dividing the IC wafer 18 into the carrier member are obtained. No complicated work such as mounting is required, and the productivity of the piezoelectric oscillator can be dramatically improved. In addition, since it is bonded to the IC wafer 18 in the state of the mother board 17, the work of mounting the supporting board 1 individually becomes unnecessary.

  Further, it is preferable that the connection pad 10 on the support substrate 1 and the electrode pad 9 on the oscillation IC 2 are connected to each other via the conductive bonding material 7 inside the sealing space 11. In addition, since the sealing state between the oscillation IC and the support substrate can be easily confirmed by visual observation or the like, the workability required for the inspection of the product is improved.

  Further, if a spacer member that contacts the IC wafer 18 and the mother substrate 17 is provided outside the region corresponding to the oscillation IC 2 and the substrate region 19 in the process B, a sealing member or the like in the manufacturing process such as a reflow process. Softening and fluctuations in the sealing space can be easily suppressed.

  For example, in the above-described embodiment, the crystal resonator element 3 is mounted on the lower surface of the oscillation IC 2. Instead, as shown in FIG. You may make it mount in a bottom face.

In the above-described embodiment, but so as to accommodate the quartz crystal vibrating element 3 into the recess 6 of the support substrate 1, as shown in FIG. 7, the present invention is the upper and lower surfaces of the oscillation IC2 of the support substrate 1 ' Is mounted on the support substrate 1 ′ or the oscillation IC 2 via the conductive adhesive 14, and the connection pads 10 on the support substrate 1 ′ and the oscillation pads are inward of the sealing space. The electrode pad 9 on the IC 2 is connected via the conductive bonding material 7, and the conductive adhesive 14 is in contact with the support substrate 1 ′ and the oscillation IC 2 as a spacer member. . The quartz crystal resonator element 3, the upper surface by mounting on a supporting substrate 1 'is planar, conductive bonding material 7 and the sealing member 8 functions as a spacer for forming a sealing space 11, these A space corresponding to the thickness is formed between the oscillation IC 2 and the support substrate 1.

As shown in FIG. 7B, it is important that the conductive adhesive 14 used for mounting the crystal resonator element 3 on the support substrate 1 ′ or the oscillation IC 2 is used as a spacer member. Thus the support substrate 1 'and on the oscillation IC2 spacer member is required separately rather names that provide a region for forming the sealing member 8 and the like during the reflow process to change the sealing space 11 is softened It becomes possible to suppress.

  Further, in the above-described embodiment, noise from the outside is shielded by attaching the shield layer 16 to the upper surface of the oscillation IC 2, but instead of this, as shown in FIG. The radio wave absorber layer 20 may be deposited on the upper surface. When such a radio wave absorber layer 20 is applied, when the crystal oscillator is used, external noise is absorbed well by the radio wave absorber layer 20 and the external noise enters the sealed space 11. This effectively prevents the crystal oscillation element 3 and the oscillation IC 2 from operating stably. In particular, if the support substrate 1 is formed of a ceramic material and the end of the radio wave absorber layer 20 extends to the support substrate 1 along the side surface of the oscillation IC 2, the noise is generated by absorbing noise from the outside. The heat energy can be dissipated well through the support substrate 1, and various inconveniences caused by the accumulation of such heat energy inside the crystal oscillator can be effectively prevented. It becomes. In addition, ceramics, glass ceramics, LTCC (Low Temperature Co-fired Ceramics), etc. are used as the ceramic material, and as a material of the radio wave absorber layer 20, a resin such as urethane foam or styrene is impregnated with carbon. A resistor type or a sintered ferrite type utilizing the magnetic loss of sintered ferrite is used.

  Further, in the above-described embodiment, the IC wafer 18 is used as a carrier member. Alternatively, the mother board 17 may be used as a carrier member. In this case, a carrier member is separately prepared, The troublesome work of mounting individual support substrates 1 obtained by dividing the mother substrate 17 on the carrier member is not required, and the productivity of the piezoelectric oscillator can be dramatically improved. In addition, since the IC wafer 18 is bonded to the mother board 17, the operation of individually mounting the oscillation IC 2 can be eliminated.

  Further, in the above-described embodiment, the surface-mount type crystal oscillator using a crystal resonator element as the piezoelectric resonator element 3 has been described as an example, but instead, a surface acoustic wave (SAW) filter or the like is used as the piezoelectric resonator element. The present invention can also be applied when other piezoelectric vibration elements are used.

Is an exploded perspective view showing an example of applying an embodiment of the pressure conductive oscillator as a reference example the crystal oscillator of the surface mount. It is sectional drawing of the crystal oscillator of FIG. It is the top view which looked at the support substrate used for the crystal oscillator of FIG. 1 from upper direction. It is the top view which looked at IC for oscillation used for the crystal oscillator of Drawing 1 from the lower part. Is a perspective view for explaining the IC wafer for use in the production method of the water crystal oscillator, is (a) is a view seen from the upper side, as viewed from (b) lower surface. Is a perspective view for explaining a mother substrate for use in the production method of the water crystal oscillator. Method for producing a water crystal oscillator is a perspective view for explaining, in particular those showing a collection piezoelectric oscillator. Method for producing a water crystal oscillator is a perspective view for explaining a shows a plurality of piezoelectric oscillators. It is sectional drawing of the piezoelectric oscillator which concerns on other embodiment as a reference example . (A) is a sectional view of the piezoelectric oscillator as a reference example, is a cross-sectional view of a piezoelectric oscillator according to Kazumi facilities form of (b) the present invention. It is sectional drawing of the piezoelectric oscillator which concerns on other embodiment as a reference example . It is sectional drawing of the piezoelectric oscillator which concerns on other embodiment as a reference example . It is a disassembled perspective view of the conventional piezoelectric oscillator.

Explanation of symbols

1 , 1 ′ , support substrate 2... IC for oscillation
3 ... Piezoelectric vibration element (crystal vibration element)
4 .... via-hole conductor 5 .... external terminal electrode 6 .... concave 7 .... conductive bonding material 8 .... sealing member 9 .... electrode pad 10 .... connection Pad 11 ... Sealing space 12 ... Substrate side sealing conductor 13 ... IC side sealing conductor 14 ... Conductive adhesive 15 ... Mounting pad 16 ... Shield layer 17 ..Mother substrate 18 ... IC wafer 19 ... Substrate area (support substrate)
20 ... Radio wave absorber layer

Claims (9)

Piezoelectric vibrations in which the upper surface of the support substrate and the lower surface of the oscillation IC are joined with a sealing member so as to form a sealed space therebetween, and are electrically connected to the oscillation IC in the sealed space. In a piezoelectric oscillator containing an element,
The upper surface of the support substrate and the lower surface of the oscillation IC are planar, and a spacer member is provided that abuts against the support substrate and the oscillation IC to suppress fluctuations in the sealing space. wherein the connection pads before Symbol supporting substrate at the inside of the sealed space and the electrode pads on the oscillation IC is connected via a conductive bonding material, said support said piezoelectric vibrating element through the conductive adhesive substrate or be mounted on the said oscillation IC, piezoelectric oscillator, characterized that you have to use the conductive adhesive as the spacer member.   The piezoelectric oscillator according to claim 1, wherein the piezoelectric vibration element is mounted on a lower surface of the oscillation IC.   The piezoelectric oscillator according to claim 1, wherein the sealing member is made of a brazing material.   The piezoelectric oscillator according to claim 1, wherein the sealing member and the conductive bonding material are made of the same metal material.   2. The piezoelectric oscillator according to claim 1, wherein the sealing member is made of a metal material, and the sealing member is electrically connected to a ground terminal on a lower surface of the support substrate.   The piezoelectric oscillator according to claim 1, wherein a shield layer is attached to an upper surface of the oscillation IC.   The piezoelectric oscillator according to claim 6, wherein an end portion of the shield layer extends to the sealing member along a side surface of the oscillation IC.   The piezoelectric oscillator according to claim 1, wherein a radio wave absorber layer is attached to an upper surface of the oscillation IC.   The support substrate is formed of a ceramic material, the sealing member is formed of a metal material, and an end portion of the radio wave absorber layer extends to the support substrate and / or the sealing member along a side surface of the oscillation IC. The piezoelectric oscillator according to claim 8, wherein

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