JP2015126534A - Piezoelectric oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric oscillator which can be reduced in size.SOLUTION: An oscillator 1 includes a substrate 5, a vibration element 7 mounted on the substrate 5, and an integrated circuit element 9 that is mounted on the substrate 5 and includes an oscillation circuit. The substrate 5 is a single-layer substrate, and includes: an insulating substrate 13; external terminals 3A to 3D provided on the insulating substrate 13; a second interconnection that is provided in a layered state on a first main surface 13a of the insulating substrate 13 and connects the integrated circuit element 9 and the vibration element 7; an insulating layer partly covering the second interconnection; and a first interconnection that is provided in a layered state astride the first main surface 13a of the insulating substrate 13 and the insulating layer, three-dimensionally intersects with the second interconnection with the insulating layer interposed therebetween, and connects the external terminals 3A to 3D with the integrated circuit element 9.

Description

  The present invention relates to a piezoelectric oscillator.

  A piezoelectric oscillator having a substrate, a vibration element mounted on one main surface of the substrate, and an integrated circuit element mounted on the one main surface is known (for example, Patent Document 1). The board | substrate of patent document 1 is comprised by the ceramic multilayer substrate. The external terminal, the vibration element, and the integrated circuit element of the substrate are connected to each other by an outer layer conductor, an inner layer conductor, a via conductor, and the like of the ceramic multilayer substrate.

JP 2011-199577 A

  Piezoelectric oscillators are required to be further miniaturized, and it is desirable to provide a piezoelectric oscillator that can meet such demands.

  The piezoelectric oscillator of the present invention includes a substrate, a vibration element mounted on the substrate, and an integrated circuit element including an oscillation circuit mounted on the substrate, and the substrate is a single layer substrate, An insulating substrate; an external terminal provided on the insulating substrate; and a layer formed on a main surface of the insulating substrate to connect the external terminal and the integrated circuit element, or the integrated circuit element and the vibration element. A lower wiring that connects the lower wiring, an insulating layer that partially covers the lower wiring, a main surface of the insulating substrate, and a layer straddling the insulating layer, and the lower wiring via the insulating layer And an upper wiring that crosses the side wiring and connects the external terminal and the integrated circuit element, or connects the integrated circuit element and the vibration element.

  Preferably, the lower wiring is a wiring that connects the integrated circuit element and the vibration element, and the upper wiring is a wiring that connects the external terminal and the integrated circuit element.

  Preferably, the oscillator includes a cap that is disposed on a main surface of the substrate and seals the vibration element, and the lower wiring extends inside and outside the cap, and the insulating layer Is also interposed between the lower wiring and the cap.

  Preferably, the oscillator includes a cap that is disposed on a main surface of the substrate and seals the vibration element, and the insulating layer is formed on the outside of the cap and on the integrated circuit element of the lower wiring. Covers more than half of the non-overlapping parts.

  Preferably, the one upper wiring is three-dimensionally crossed with respect to the two lower wirings to form two three-dimensional intersections, and the insulating layer includes the two three-dimensional intersections and the space therebetween. The one upper wiring is overlapped with the two three-dimensional intersections and the insulating layer therebetween.

  Preferably, the substrate further includes a front and back connection conductor provided on an outer peripheral surface of the insulating substrate and extending from one main surface to the other main surface, and the insulating layer also covers the front and back connection conductors. .

  Preferably, the insulating layer is made of glass.

  According to said structure, size reduction of a piezoelectric oscillator is realizable.

The perspective view which shows the structure of the piezoelectric oscillator which concerns on embodiment of this invention. The disassembled perspective view of the piezoelectric oscillator of FIG. Sectional drawing of the piezoelectric oscillator in the III-III line | wire of FIG. The figure which shows the lower wiring layer of the board | substrate of the piezoelectric oscillator of FIG. The figure which shows an insulating layer in addition to FIG. The figure which shows an upper side wiring layer in addition to FIG. The figure which shows the upper surface of the board | substrate of the piezoelectric oscillator of FIG. 8A to 8C are cross-sectional views taken along lines VIIIa-VIIIa, VIIIb-VIIIb, and VIIIc-VIIIc in FIG. 3 is a flowchart illustrating an example of a procedure of a method for manufacturing the piezoelectric oscillator of FIG. 1. FIG. 10A is a perspective view showing a corner portion of the substrate according to the modified example, and FIGS. 10B and 10C are sectional views of the corner portion of the substrate according to the modified example of FIG.

  Hereinafter, an oscillator according to an embodiment of the present invention will be described with reference to the drawings. Note that the drawings used in the following description are schematic, and the dimensional ratios and the like on the drawings do not necessarily match the actual ones.

  Moreover, the same code | symbol may be attached | subjected about the same or similar structure. In this case, the same or similar configurations may be distinguished from each other by adding capital letters to the reference numerals such as “external terminal 3” as “external terminal 3A” and “external terminal 3B”.

  FIG. 1 is a perspective view showing a configuration of an oscillator 1 according to an embodiment of the present invention. In FIG. 1, a part of the configuration on the upper side of the oscillator 1 is indicated by a dotted line, and the inside of the oscillator 1 is indicated by a solid line.

  Note that the oscillator 1 may have either direction upward or downward, but in the following embodiments, for convenience, the orthogonal coordinate system xyz is defined and the positive side in the z direction is defined as the upward direction. , Upper surface, lower surface, etc. may be used.

  For example, the oscillator 1 is generally formed in a thin, rectangular parallelepiped shape as a whole. A plurality (four in this embodiment) of external terminals 3 are exposed on the lower surface (see also FIG. 2). The oscillator 1 is mounted on a circuit board, for example, with a lower surface facing a circuit board (not shown) and pads provided on the circuit board and four external terminals 3 are fixed by soldering or the like.

  Three of the four external terminals 3 are generated by, for example, a GND terminal to which a reference potential is applied, a Vcc terminal to which a drive potential is applied (a terminal to which DC power is supplied by a potential difference from the reference potential), and an oscillator 1 An output terminal for outputting an oscillation signal to be output. The remaining one is, for example, an E / D terminal to which a signal for controlling the output and stop of the oscillation signal from the oscillator 1 is input, or a Vcon terminal to which a frequency adjustment signal for controlling the frequency of the oscillation signal is input. It is.

  As described above, all the external terminals 3 are used for inputting or outputting signals (potentials) necessary for the operation of the oscillator 1 as a product. That is, the oscillator 1 does not have an external terminal that is used only in the manufacturing process. The specific arrangement and shape of the external terminal 3 will be described later.

  Note that any function terminal may be assigned to any external terminal 3, but as an example, the external terminal 3A is a Vcon terminal, the external terminal 3B is a GND terminal, the external terminal 3C is an output terminal, and the external terminal 3D is Vcc. Terminal.

  2 is an exploded perspective view of the oscillator 1 (however, some members are omitted), and FIG. 3 is a cross-sectional view of the oscillator 1 taken along line III-III in FIG.

  As shown in FIGS. 1 to 3, the oscillator 1 includes, for example, a substrate 5, a vibration element 7 (FIGS. 2 and 3) mounted on the substrate 5, an integrated circuit element 9 mounted on the substrate 5, A cap 11 covering the vibration element 7 and a sealing resin 12 (shown by dotted lines in FIGS. 1 and 3) for sealing the integrated circuit element 9 and the like are provided.

  The external terminal 3 described above is provided on the substrate 5 and connected to the integrated circuit element 9. The integrated circuit element 9 is connected to the vibration element 7 via the substrate 5, and generates an oscillation signal by applying a voltage to the vibration element 7. The cap 11 seals the vibration element 7, and the sealing resin 12 seals the cap 11 and the integrated circuit element 7 sealing the vibration element 7. Specific configurations of these members are as follows.

  The substrate 5 is configured by a so-called single layer substrate. Here, the single-layer substrate has a conductive layer parallel to these principal surfaces only on one principal surface or both principal surfaces of the insulation substrate, and the insulation substrate has a conductive layer parallel to the principal surface. The one that does not have a layer. The single-layer substrate may have a conductor (which may be a conductive layer) extending in the thickness direction of the insulating substrate on the side surface or inside of the insulating substrate in order to connect the conductive layers on both main surfaces to each other. For this reason, since it is not necessary to provide a conductive layer parallel to the main surface inside the substrate 5, the substrate 5 can be thinned for the thickness of the conductive layer.

  In the present embodiment, as particularly shown in FIGS. 1 and 2, the substrate 5 includes an insulating substrate 13 and a first conductive surface provided on one main surface (first main surface 13 a) of the insulating substrate 13. A plurality of layers (this embodiment) connecting the layer 15A, the second conductive layer 15B provided on the other main surface (second main surface 13b) of the insulating substrate 13, and the first conductive layer 15A and the second conductive layer 15B. 4) front and back connection conductors 17 are provided.

  The insulating substrate 13 does not have flexibility, for example. That is, the substrate 5 is a so-called rigid circuit substrate. The material of the insulating substrate 13 is mainly ceramic or resin, for example. The planar shape of the insulating substrate 13 may be set as appropriate, but is, for example, generally rectangular.

  As shown particularly in FIG. 2, the first conductive layer 15A includes a plurality of (four in the present embodiment) to which the pair of vibration element pads 19 on which the vibration element 7 is mounted and the integrated circuit element 9 are connected. A first integrated circuit element pad 21, a pair of second integrated circuit element pads 23, and a plurality of wirings connecting the pads and the front and back connection conductors 17. Specific positions and shapes of these pads and wiring will be described later.

  The second conductive layer 15B includes the plurality of external terminals 3B described above.

  The plurality of front and back connecting conductors 17 are formed, for example, on the inner surface of a groove (castellation) extending in the thickness direction of the substrate 5 formed on the outer peripheral surface of the substrate 5 (more specifically, the corner in this embodiment). It is composed of a conductive layer.

  The first conductive layer 15A, the second conductive layer 15B, and the front / back connection conductor 17 are made of, for example, a metal such as Cu or Al. These may be formed of materials and thicknesses different from each other. Further, the material and thickness may be different between the pad and the wiring in the first conductive layer 15A. For example, the wiring may be formed of a Cu layer, and the pad may be configured by performing nickel plating and gold plating on the Cu layer.

  The configuration of the vibration element 7 may be a known configuration. For example, as shown in FIGS. 2 and 3, the vibration element 7 includes a piezoelectric body 25 formed in a flat plate shape and a pair of excitation electrodes 27 (FIG. 2. One side) provided on both main surfaces of the piezoelectric body 25. The excitation electrode 27 includes a pair of extraction electrodes 29 connected to the pair of excitation electrodes 27 (not shown) hidden behind the piezoelectric body 25.

  The piezoelectric body 25 is made of, for example, quartz, and its planar shape is rectangular. The pair of excitation electrodes 27 are layered electrodes that cover a relatively wide range of the main surface of the piezoelectric body 25, and the planar shape thereof is rectangular. For example, the pair of extraction electrodes 29 are provided side by side in the lateral direction at one end in the longitudinal direction of the piezoelectric body 25.

  For example, the vibration element 7 is mounted on the substrate 5 by fixing the pair of extraction electrodes 29 and the pair of vibration element pads 19 by the conductive adhesive 31 (FIG. 3). The vibration element 7 has, for example, a direction (y direction) in which the end portion on the side where the pair of extraction electrodes 29 is provided intersects (more specifically, intersects) the arrangement direction of the vibration element 7 and the integrated circuit element 9. Placed towards the.

  The integrated circuit element 9 operates by being supplied with DC power from the GND terminal and the Vcc terminal (external terminal 3). Further, the integrated circuit element 9 outputs an oscillation signal having a predetermined frequency generated by applying a voltage to the vibration element 7 from the Output terminal (external terminal 3). Further, the integrated circuit element 9 allows or prohibits the output of the oscillation signal from the Output terminal based on the signal from the E / D terminal (external terminal 3), or uses the signal from the Vcon terminal (external terminal 3) as a signal. Based on this, the frequency of the oscillation signal is adjusted.

  The configuration of the integrated circuit element 9 may be a known configuration including the configuration of the oscillation circuit. The integrated circuit element 9 may be a so-called bare chip or a packaged one.

  For example, the integrated circuit element 9 is formed in a substantially rectangular parallelepiped shape, and has a plurality of connection pads 33 (FIG. 3) on its lower surface. The plurality of connection pads 33 are connected to and fixed to the plurality of integrated circuit element pads (21 and 23) by a plurality of bumps 35 (FIG. 3). An underfill 36 (FIGS. 1 and 3) is filled in the gap between the integrated circuit element 9 and the substrate 5, which is configured by the thickness of the bumps 35 and the like.

  The bump 35 is made of, for example, solder (including lead-free solder) or a conductive adhesive. The underfill 36 is mainly made of resin, for example. The underfill 36 may include a filler made of an inorganic material.

  The cap 11 is formed, for example, in a substantially box shape, and is placed on the first main surface 13 a of the substrate 5 so as to cover the vibration element 7. For example, the cap 11 and the first main surface 13 a are fixed by the adhesive layer 14 (FIGS. 1 and 3) over the entire circumference of the lower end of the cap 11. Thereby, the vibration element 7 is sealed. The cap 11 is made of, for example, a metal, and thereby the thickness is reduced while ensuring the strength.

  The sealing resin 12 covers, for example, the first main surface 13a, the cap 11, and the integrated circuit element 9. The shape of the outer surface of the sealing resin 12 may be set as appropriate. For example, it is a thin rectangular parallelepiped shape having an area equivalent to that of the substrate 5. The sealing resin 12 may include a filler made of an inorganic material.

  4 to 6 are top views showing the configuration of the first conductive layer 15A. As shown in FIG. 4, a lower wiring layer 51 is first provided on the first major surface 13a. Next, as shown in FIG. 5, an insulating layer 53 that partially covers the lower wiring layer 51 is provided. Thereafter, as shown in FIG. 6, the upper wiring layer 55 is provided on the first main surface 13 a and the insulating layer 53. The lower wiring layer 51 and the upper wiring layer 55 constitute a first conductive layer 15A. And since the insulating layer 53 is interposed between the lower wiring layer 51 and the upper wiring layer 55, they can be three-dimensionally crossed.

  The lower wiring layer 51 and the upper wiring layer 55 are made of, for example, a metal such as Cu or Al. Both may be the same material or different materials. Further, both may have the same thickness or may have different thicknesses. Since the upper wiring layer 55 is provided across the step formed by the thickness of the lower wiring layer 51 and the insulating layer 53, the upper wiring layer 55 is formed thicker than the lower wiring layer 51 so as not to be disconnected by this step, etc. It is preferable to form it relatively thick.

  The insulating layer 53 is made of, for example, glass (glass coat layer). The glass contains, for example, borosilicate glass as a main component. The thickness of the insulating layer 53 may be an appropriate thickness as long as the lower wiring layer 51 and the upper wiring layer 55 can be insulated.

  FIG. 7 is a view showing the upper surface of the substrate 5. In FIG. 7, the outer shape of the vibration element 7, the outer shape of the integrated circuit element 9, and the lower surface outer shape of the cap 11 are indicated by two-dot chain lines. Further, a portion of the lower wiring layer 51 covered with the insulating layer 53 is indicated by a dotted line.

  As described above, the plurality of external terminals 3 are connected to the integrated circuit element 9. Between the plurality of external terminals 3 and the integrated circuit element 9, a plurality of front and back connection conductors 17, a plurality of first wirings 37, and a plurality of first integrated circuit element pads 21 are sequentially disposed. Note that these are the same number (four in this embodiment).

  The integrated circuit element 9 is connected to the vibration element 7. Between the integrated circuit element 9 and the vibration element 7, a pair of second integrated circuit element pads 23, a pair of second wirings 39, and a pair of vibration element pads 19 are sequentially disposed.

  Further, in the manufacturing process of the oscillator 1, two of the plurality of external terminals 3 are also connected to the vibration element 7 by a pair of cutting patterns 41. This cutting pattern 41 is cut before the oscillator 1 is completed. 7 shows a state after cutting, and FIGS. 2 and 4 to 6 show a state before cutting.

  Specifically, for example, the cutting pattern 41A extends from the first integrated circuit element pad 21A to the second integrated circuit element pad 23A. Thereby, the external terminal 3A and the vibration element pad 19A are connected. For example, the cutting pattern 41B extends from the first wiring 37C to the second wiring 39B. Thereby, the external terminal 3C and the vibration element pad 19B are connected.

  As described above, the substrate 5 is composed of a single-layer substrate that does not have a conductive layer parallel to the main surface. The wirings (first wiring 37 and the like) for connecting the front and back connection conductors 17, the first integrated circuit element pads 21, the second integrated circuit element pads 23, and the vibration element pads 19 to each other are all first main surfaces. 13a.

  Specifically, the first wiring 37 extends from the front / back connection conductor 17 to the first integrated circuit element pad 21 on the first main surface 13a. The second wiring 39 extends from the second integrated circuit element pad 23 to the vibration element pad 19 on the first main surface 13a. The cutting pattern 41 also extends on the first main surface as described above.

  The relationship between the various pads and wirings and the above-described lower wiring layer 51 and upper wiring layer 55 is, for example, as follows.

  The first wirings 37 </ b> A and 37 </ b> C, the pair of second wirings 39, the pair of vibration element pads 19, and the pair of cutting patterns 41 are configured by the lower wiring layer 51. On the other hand, the first wirings 37 </ b> B and 37 </ b> D, the four first integrated circuit element pads 21, and the pair of second integrated circuit element pads 23 are configured by an upper wiring layer 55.

  The second wiring 39 </ b> B of the lower wiring layer 51 and the first wiring 37 </ b> D of the upper wiring layer 55 cross three-dimensionally through the insulating layer 53. The second wiring 39 </ b> A of the lower wiring layer 51 and the first wiring 37 </ b> B of the upper wiring layer 55 cross three-dimensionally through the insulating layer 53. The first wiring 37 </ b> A of the lower wiring layer 51 and the first wiring 37 </ b> B of the upper wiring layer 55 cross three-dimensionally through the insulating layer 53.

  As described above, in the present embodiment, the pair of second wirings 39 connected to the vibration element 7 includes only the lower wiring layer 51, and the upper wiring layer 55 is integrated with the external terminal 3. This is used to configure at least a part of the first wiring 37 that connects the circuit element 9. Compared with the lower wiring layer 51, the upper wiring layer 55 has a high probability of being formed thick so as not to be disconnected at a step, and errors in thickness and shape are likely to occur due to variations in the step. Therefore, by configuring the second wiring 39 with only the lower wiring layer 51, the influence of the second wiring 39 on the electrical characteristics of the vibration element 7 can be reduced.

  In this embodiment, the vibration element pad 19 is constituted by the lower wiring layer 51, and the first integrated circuit element pad 21 and the second integrated circuit element pad 23 are constituted by the upper wiring layer 55. However, since these pads basically do not cross three-dimensionally, they may be constituted by any wiring layer or may be constituted by the same wiring layer.

  The second wiring 39 extends in and out of the cap 11, and the insulating layer 53 is also interposed between the second wiring 39 and the cap 11 (an adhesive region with respect to the substrate 5). Therefore, for example, the electrical characteristics of the second wiring 39 and the vibration element 7 are suppressed from being changed before and after the cap 11 is attached. As a result, for example, the measurement result of the electrical characteristics of the vibration element 7 before the cap 11 is attached can be appropriately used for a finished product.

  The insulating layer 53 covers more than half of the second wiring 39 outside the cap 11 and not overlapping the integrated circuit element 9. Therefore, for example, the possibility that dust or the like adheres to the second wiring 39 in the manufacturing process is reduced. As a result, for example, the electrical characteristics of the second wiring 39 and the vibration element 7 are suppressed from changing in the manufacturing process, and as a result, the measurement result of the electrical characteristics of the vibration element 7 in the manufacturing process is appropriately used for the finished product. it can.

  In the present embodiment, the first wiring 37B crosses not only the second wiring 39A but also the first wiring 37A. That is, one wiring of the upper wiring layer 55 crosses three wirings of the lower wiring layer 51 three-dimensionally. The insulating layer 53 extends between the two three-dimensional intersections and between them, and the first wiring 37B overlaps the two three-dimensional intersections and the insulating layer 53 between them.

  Therefore, for example, the insulating layer 53 does not constitute a step between the two three-dimensional intersections. As a result, the level difference between the first wirings 37B overlaid on the insulating layer 53 is reduced, and the risk of disconnection of the first wirings 37B is reduced.

  The insulating layers 53 are also provided at the four corners of the first main surface 13a. That is, it covers the periphery of a groove (castellation) for providing the front and back connecting conductors 17 in the first main surface 13a. Therefore, for example, the strength of the substrate 5 is reinforced at a position where stress concentration is likely to occur, and disconnection or the like due to cracks is suppressed.

  Fig.8 (a) is sectional drawing of the VIIIa-VIIIa line | wire of FIG.

  As described above, the lower wiring layer 51, the insulating layer 53, and the upper wiring layer 55 are stacked in order from the bottom on the first main surface 13a. FIG. 8A is a cross section at a position where the adhesive layer 14 does not adhere to the first main surface 13a. The thickness of the adhesive layer 14 from the first main surface 13a is as follows: the lower wiring layer 51, the insulating layer 53, and It is thicker than the total thickness of the upper wiring layer 55. The adhesive layer 14 includes the first main surface 13a, the insulating layer 53 or the upper wiring layer 55, and the lower surface of the cap 11 regardless of the steps due to the thicknesses of the lower wiring layer 51, the insulating layer 53, and the upper wiring layer 55. Is glued.

  8B is a cross-sectional view taken along line VIIIb-VIIIb in FIG. 7, and FIG. 8C is a cross-sectional view taken along line VIIIc-VIIIc in FIG.

  As described above, the insulating layer 53 covers the periphery of the groove (castellation) for providing the front and back connection conductors 17 on the first main surface 13a. The lower wiring layer 51 and the front / back connection conductor 17 are connected below the insulating layer 53, and the upper wiring layer 55 and the front / back connection conductor 17 are connected above the insulating layer 53.

  FIG. 9 is a flowchart showing an example of the procedure of the method for manufacturing the oscillator 1.

  First, the substrate 5, the vibration element 7 and the integrated circuit element 9 are prepared. The substrate 5 is in a state where the cutting pattern 41 has not been cut yet. The manufacturing method of the vibration element 7 and the integrated circuit element 9 may be the same as a known method.

  For example, when the insulating substrate 13 is made of ceramic, the substrate 5 has a conductive paste that becomes the lower wiring layer 51, a glass paste that becomes the insulating layer 53, an upper side of one surface of the ceramic green sheet that becomes the insulating substrate 13. A conductive paste for forming the wiring layer 55 is sequentially applied by screen printing or the like. In addition, by forming a hole to be a groove (castellation) on the ceramic green sheet at an appropriate time and performing screen printing while sucking the hole, the conductive paste to be the external terminal 3 is transferred to the other surface of the ceramic green sheet. In addition, a conductive paste to be the front and back connection conductor 17 is applied to the inner peripheral surface of the hole. Then, the ceramic green sheet coated with the conductive paste is fired. In addition, baking may be performed whenever it arrange | positions a conductive paste or a glass paste.

  Further, for example, when the insulating substrate 13 is made of a resin or the like, formation of a thin film, formation of a mask by photolithography, etching through the mask, and removal of the mask are repeated, and the lower wiring layer 51, the insulating layer 53, and the upper side are sequentially repeated. A wiring layer 55 is formed. The external terminal 3 is formed in the same manner. In addition, a hole to be a groove (castellation) is formed in the insulating substrate 13 at an appropriate time, and the front and back connection conductors 17 are formed on the inner peripheral surface thereof by plating or the like.

  Next, the vibration element 7 is mounted on the substrate 5 (step ST1). Specifically, for example, the conductive adhesive 31 is disposed on the pair of vibration element pads 19, and then the vibration element 7 is disposed so that the extraction electrode 29 contacts the conductive adhesive 31. . Then, the conductive adhesive 31 is heated and cured.

  Next, the frequency of the vibration element 7 is adjusted (step ST2). Specifically, for example, first, the substrate 5 on which the vibration element 7 is mounted is placed in a vacuum atmosphere. Further, the probe of the electrical characteristic test apparatus (not shown) is brought into contact with the external terminals 3A and 3C. That is, the electrical characteristic test apparatus and the vibration element 7 are connected via the external terminal 3. Then, the oscillation frequency of the vibration element 7 is measured, and the excitation electrode 27 is etched with a laser or the like based on the measurement result, or conversely, a metal is deposited on the piezoelectric body 25. Thus, the oscillation frequency of the vibration element 7 is adjusted.

  Next, the vibration element 7 is sealed (step ST3). Specifically, for example, a glass sealing material is applied to one of the substrate 5 and the cap 11. Then, the cap 11 is placed on the substrate 5 in a vacuum atmosphere. Then, the glass sealing material is heated and then cooled to join the cap 11 to the substrate 5 and seal the vibration element 7.

  Next, the characteristic inspection of the vibration element 7 is performed (step ST4). Specifically, for example, first, a probe of an electrical characteristic test apparatus (not shown) is brought into contact with the external terminals 3A and 3C. That is, the electrical characteristic test apparatus and the vibration element 7 are connected via the external terminal 3. Then, for example, the oscillation frequency and crystal impedance value (CI value) of the vibration element 7 are measured.

  In addition, compared with the measurement result at the time of the frequency adjustment in step ST2, the inspection result includes a characteristic change accompanying the attachment of the cap 11 in step ST3. However, as described above, since the insulating layer 53 is provided so as to cover a part of the second wiring 39, the influence of the cap 11 on the second wiring 39 is mitigated by the insulating layer 53. Dust adhesion to the second wiring 39 is also suppressed by the insulating layer 53. For this reason, it is possible to suppress a change in the oscillation frequency of the vibration element 7 transmitted through the second wiring 39 and measured by the external terminal 3 due to the adhesion of dust, or an increase in the crystal impedance value (CI value). The inspection result measured at the external terminal 3 is used for adjustment of the oscillation frequency by the integrated circuit element 9, for example. For example, the capacitance of the variable capacitance element included in the oscillation circuit of the integrated circuit element 9 is set based on the inspection result.

  Next, the pair of cutting patterns 41 are cut (step ST5). Specifically, for example, the cutting pattern 41 is cut by irradiating a laser beam. At this time, depending on the intensity of the laser beam or the irradiation time, not only the cutting pattern 41 but also a part of the surface of the substrate 5 is removed at the cutting position, and a recess is formed in the first main surface 13a. There is a case. This concave portion is evidence that the cutting pattern 41 exists in the oscillator 1 completed as a product.

  Next, the integrated circuit element 9 is mounted on the substrate 5 (step ST6). Specifically, for example, solder that becomes the bumps 35 is disposed on the plurality of first integrated circuit element pads 21 and the pair of second integrated circuit element pads 23, and the integrated circuit element 9 is placed thereon. And transport to the reflow oven.

  Next, the underfill 36 is filled between the substrate 5 and the integrated circuit element 9 (step ST7). For filling, a known method such as a method using a capillary phenomenon (side fill method) may be used.

  Next, the sealing resin 12 is provided on the substrate 5 (step ST8). For example, the molten resin is placed on the substrate 5 and solidified by a known method such as a printing method or a dispenser method.

  Thereafter, an electrical characteristic inspection is performed (step ST9). Specifically, for example, first, a probe of an electrical characteristic inspection device (not shown) is brought into contact with the external terminal 3. That is, the electrical characteristic inspection apparatus is connected to the integrated circuit element 9 through the external terminal 3. Then, the oscillation frequency and the like are measured.

  As described above, the oscillator 1 according to this embodiment includes the substrate 5, the vibration element 7 mounted on the substrate 5, and the integrated circuit element 9 including the oscillation circuit mounted on the substrate 5. The substrate 5 is formed of a single layer substrate, and is provided in layers on the insulating substrate 13, the external terminals 3 provided on the insulating substrate 13, and the first main surface 13 a of the insulating substrate 13, and includes the integrated circuit element 9 and the vibration element 7. A second wiring 39 that connects the first wiring 39, an insulating layer 53 that partially covers the second wiring 39, a first main surface 13a of the insulating substrate 13 and an insulating layer 53. And a first wiring 37 that three-dimensionally intersects the second wiring 39 and connects the external terminal 3 and the integrated circuit element 9.

  Therefore, the thickness can be reduced by making the substrate a single layer. If a single layer is used, the wiring pattern may be complicated in order to avoid the intersection of the wiring. However, the degree of freedom of the wiring is improved by the three-dimensional intersection via the insulating layer 53, and thus the wiring pattern is simplified. Minimization is expected. By shortening the wiring pattern, it is expected that the signal coupling between the wirings is reduced and the electrical characteristics are stabilized. Further, since the degree of freedom of wiring is improved, it is easy to use the existing integrated circuit element 9 while complying with the specifications of the mounting board on which the oscillator 1 is mounted (specifications required for the external terminals 3). The That is, it is not necessary to set the role of the connection pad 33 of the integrated circuit element 9 according to the specifications of the external terminal 3 and redesign the integrated circuit element 9. As a result, cost reduction is achieved.

  FIG. 10A is a perspective view showing a modification in the vicinity of the front and back connection conductors 17, and FIGS. 10B and 10C show FIGS. 8B and 8C showing the modification. Is a cross-sectional view corresponding to FIG.

  In this modification, the insulating layer 53 also covers the front and back connection conductors 17. As shown in FIG. 10B, the lower wiring layer 51 and the front / back connection conductor 17 are connected, and the insulating layer 53 is covered from above. Further, as shown in FIG. 10C, the upper wiring layer 55 and the front / back connection conductor 17 are connected via the lower wiring layer 51, for example.

  In the manufacture of this modified example, for example, the front and back connection conductors 17 are formed before the insulating layer 53 is formed, and then screen printing is performed while sucking holes serving as grooves (castellations). Then, a glass paste that becomes the insulating layer 53 is applied to the inner peripheral surface of the hole, and then the upper wiring layer 55 is formed.

  In addition, it is good also as forming the insulating layer 53 which covers the front-and-back connection conductor 17 separately from the insulating layer 53 interposed between the lower wiring layer 51 and the upper wiring layer 55 for the three-dimensional intersection. For example, after forming the lower wiring layer 51, the insulating layer 53 and the upper wiring layer 55 partially covering the lower wiring layer 51, the front and back connection conductors 17 may be formed, and the insulating layer 53 covering the upper and lower connection layers 17 may be formed. In this case, the upper wiring layer 55 and the front / back connection conductor 17 are directly connected.

  As in this modification, the front and back connection conductors 17 are also covered with the insulating layer 53, so that, for example, when the oscillator 1 is mounted on the mounting board by solder, the solder travels along the front and back connection conductors 17 more than necessary. The flow toward the surface 13a is suppressed. As a result, for example, the amount of solder is stabilized, and as a result, the electrical characteristics are stabilized.

  In the above embodiment and the like, the oscillator 1 is an example of the piezoelectric oscillator of the present invention, the second wiring 39 and the first wiring 37A are examples of the lower wiring of the present invention, and the first wirings 37B and 37D are It is an example of the upper wiring of this invention.

  The present invention is not limited to the above embodiment, and may be implemented in various aspects.

  The number of external terminals, front and back connection conductors, first integrated circuit element pads, and first wirings is not limited to four. Since it is sufficient that the electrical characteristics of the vibration element can be measured via two external terminals, it is sufficient that the number of external terminals is two or more. For example, only the GND terminal and the Vcc terminal may be provided, and the oscillation signal may be output wirelessly from the integrated circuit element. For example, six external terminals may be provided. In this case, for example, two output terminals that output the same or different oscillation signals may be provided as external terminals, or a terminal that outputs the temperature around the oscillator may be provided.

  The direction of the vibration element is not limited to the direction in which the direction orthogonal to the arrangement direction of the vibration element and the integrated circuit element is the longitudinal direction of the vibration element. For example, the direction of the vibration element may be a direction in which the arrangement direction is the longitudinal direction of the vibration element.

  The front and back connection conductors are not limited to the conductive layer formed on the inner surface of the side groove. For example, the front and back connection conductors may be a conductive layer formed on the inner surface of a through hole (through hole) penetrating the insulating substrate or a conductor filled in the through hole.

  The integrated circuit element is not limited to that mounted on the integrated circuit element pad via the bump. For example, the integrated circuit element may be fixed to an area surrounded by the integrated circuit element pad by an adhesive or the like and connected to the integrated circuit element pad by wire bonding.

  The cutting pattern may not be provided. That is, an external terminal dedicated for inspection of the vibration element may be provided.

  In the embodiment, the three-dimensional intersection between the first wiring and the second wiring and the three-dimensional intersection between the second wirings are exemplified. However, the first wires may be three-dimensionally crossed. Further, the first wiring may be constituted by an upper wiring layer.

  DESCRIPTION OF SYMBOLS 1 ... Oscillator, 3 ... External terminal, 5 ... Board | substrate, 7 ... Vibration element, 9 ... Integrated circuit element, 13 ... Insulation board | substrate, 13a ... 1st main surface, 13b ... 2nd main surface, 17 ... Front and back connection conductor, 19 ... vibration element pad, 21 ... first integrated circuit element pad, 23 ... second integrated circuit element pad, 37B and 37D ... first wiring (upper wiring), 39 ... second wiring (lower wiring), 41 ... Cutting pattern, 51 ... Lower wiring layer, 53 ... Insulating layer, 55 ... Upper wiring layer.

Claims (7)

A substrate,
A vibration element mounted on the substrate;
An integrated circuit element including an oscillation circuit mounted on the substrate;
Have
The substrate comprises a single layer substrate,
An insulating substrate;
An external terminal provided on the insulating substrate;
Provided in a layered manner on the main surface of the insulating substrate, connecting the external terminal and the integrated circuit element, or a lower wiring connecting the integrated circuit element and the vibration element,
An insulating layer partially covering the lower wiring;
Provided in layers over the main surface of the insulating substrate and over the insulating layer, three-dimensionally intersect the lower wiring via the insulating layer, and connect the external terminal and the integrated circuit element, or An upper wiring connecting the integrated circuit element and the vibration element;
A piezoelectric oscillator. The lower wiring is a wiring for connecting the integrated circuit element and the vibration element,
The piezoelectric oscillator according to claim 1, wherein the upper wiring is a wiring that connects the external terminal and the integrated circuit element. A cap disposed on the main surface of the substrate and sealing the vibration element;
The lower wiring extends over the inside and outside of the cap,
The piezoelectric oscillator according to claim 2, wherein the insulating layer is also interposed between the lower wiring and the cap. A cap disposed on the main surface of the substrate and sealing the vibration element;
The piezoelectric oscillator according to claim 2, wherein the insulating layer covers more than half of the lower wiring outside the cap and not overlapping the integrated circuit element. One of the upper wirings is three-dimensionally crossed with respect to the two lower wirings to form two three-dimensional intersections,
The insulating layer extends between the two three-dimensional intersections and between them,
The piezoelectric oscillator according to any one of claims 1 to 4, wherein the one upper wiring overlaps the two three-dimensional intersections and the insulating layer therebetween. The substrate is further provided on the outer peripheral surface of the insulating substrate, and further has front and back connection conductors extending from one main surface to the other main surface,
The piezoelectric oscillator according to claim 1, wherein the insulating layer also covers the front and back connection conductors. The piezoelectric oscillator according to claim 1, wherein the insulating layer is made of glass.

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