Piezoelectric vibration device

Abstract

This allows for easy inspection of piezoelectric vibrators and prevents electrical short circuits at the inspection terminals caused by external factors when mounting the piezoelectric vibration device to an external circuit after inspection. [Solution] A pair of inspection terminals 26a, 26b and a pair of common wiring sections 27a, 27b are provided on the lower surface 2b of the insulating substrate 2 in a position that does not overlap with the external connection terminals 25a to 25d. Both inspection terminals 26a, 26b are connected to a pair of excitation electrodes of a piezoelectric vibrator mounted on the upper surface of the insulating substrate 2, and both common wiring sections 27a, 27b are connected to the third and first external connection terminals 25c, 25a, respectively. The upper and lower surfaces 2b of the insulating substrate 2, including the inspection terminals 26a, 26b and the common wiring sections 27a, 27b, are covered with an insulating base material film 7. After characteristic testing of the device using the third and first external connection terminals 25c, 25a, both common wiring sections 27a, 27b are cut off together with the base material film 7 by the divided sections Da, Db.

Description

Technical Field

[0001] The present invention relates to a piezoelectric vibration device including an insulating substrate, a piezoelectric vibrator mounted on one main surface of the insulating substrate, and an integrated circuit element.

Background Art

[0002] As a piezoelectric vibration device, for example, there is a device disclosed in Patent Document 1. This piezoelectric vibration device further includes a storage unit having an electrode pad for inputting information inside a package that houses a piezoelectric vibration piece and an integrated circuit, and is provided with conduction means that conducts to the electrode pad and conducts between the inner surface and the outer surface of the package, and connects an adjustment terminal provided on the outer surface of the package to the conduction means by a cutable wiring pattern.

[0003] Also, the piezoelectric vibration device described in Patent Document 2 is provided with a component mounting surface having a wiring pattern including a plurality of pads on one main surface of a resin substrate, and a mounting surface having external connection terminals that are connected to the wiring pattern and used for connection to an external substrate on the other main surface. At least the piezoelectric vibrator is mounted on the component mounting surface of the resin substrate in a state of being connected to a plurality of pads, and at least a part of the component mounting surface is covered with a resin mold part so as to include at least the piezoelectric vibrator. Then, in order to be able to confirm the characteristics of the piezoelectric vibrator, an inspection terminal is formed that is connected to the piezoelectric vibrator via a connection terminal on the component mounting surface side without passing through the external connection terminal on the mounting surface side of the resin substrate, and the insulating resin in the insulating region covering the inspection terminal can be peeled off during inspection so that the inspection terminal can be exposed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

[0005] Incidentally, the adjustment terminal in the configuration described in Patent Document 1 above can also be used, for example, as an inspection terminal for characteristic testing of a piezoelectric vibration device. However, if it is used as an inspection terminal, the inspection terminal and wiring pattern for adjusting the piezoelectric vibration device will remain as they are. As a result, wiring patterns and inspection terminals unrelated to the original operation of the piezoelectric vibration device will remain on the package surface, and there is a risk that the inspection terminal may short-circuit when the piezoelectric vibration device is mounted and joined to an external circuit board, which could adversely affect the performance of the device.

[0006] On the other hand, the configuration described in Patent Document 2 has the advantage that the characteristics of the piezoelectric vibrator can be checked without removing the molding resin and while suppressing the effects of parasitic capacitance, because the inspection terminals are formed in a simple path on the mounting surface of the resin substrate and do not overlap with the external connection terminals, and the inspection terminals are not molded with molding resin. However, since the inspection terminals that are exposed during inspection remain exposed even after the inspection is completed, there is a risk that the inspection terminals may short-circuit when the piezoelectric vibration device is mounted on an external circuit board and joined, which, like the technology described in Patent Document 1, may adversely affect the performance of the piezoelectric vibration device.

[0007] The present invention has been made in view of the above problems, and aims to facilitate the inspection of piezoelectric vibrators and to prevent electrical short circuits caused by external factors from occurring at the inspection terminals when the piezoelectric vibrator is mounted and joined to an external circuit board after the inspection is completed. [Means for solving the problem]

[0008] To achieve the above objectives, the piezoelectric vibration device according to the present invention comprises an insulating substrate and a piezoelectric vibrator and an integrated circuit element mounted on one main surface of the insulating substrate, wherein the piezoelectric vibrator comprises a piezoelectric vibration element having a pair of excitation electrodes and a sealing member that seals the piezoelectric vibration element in an hermetically sealed state, the integrated circuit element comprises an oscillation amplification circuit to which input terminals and output terminals are connected to the input side and output side of the pair of excitation electrodes of the piezoelectric vibration element, respectively, and the insulating substrate comprises the one main surface and the other main surface provided with at least a pair of external connection terminals connected to the integrated circuit element The device comprises a surface, at least a pair of inspection terminals provided on the other main surface in a position not overlapping with the pair of external connection terminals and connected to the pair of excitation electrodes of the piezoelectric vibrator, at least a pair of common wiring sections provided on the other main surface in a position not overlapping with the pair of external connection terminals and connecting the pair of inspection terminals to the pair of external connection terminals, respectively, and an insulating base material film covering the surfaces of both main surfaces, including the pair of inspection terminals and the pair of common wiring sections, except for a portion of both main surfaces, wherein the pair of common wiring sections are provided with a divided portion that is cut off together with the base material film at at least one location.

[0009] In this configuration, a pair of inspection terminals and a pair of common wiring sections are provided on the other main surface of the insulating substrate in a position that does not overlap with a pair of external connection terminals. These inspection terminals and common wiring sections connect a pair of excitation electrodes of a piezoelectric vibrator on one main surface of the insulating substrate to a pair of external connection terminals. The surfaces of both main surfaces of the insulating substrate, including the pair of inspection terminals and the pair of common wiring sections, are covered with an insulating base film. After the inspection is completed, at least one of the pair of common wiring sections is cut off together with the base film, forming a divided section.

[0010] Therefore, the piezoelectric vibrator can be inspected using a pair of external connection terminals, and after the inspection is complete, the pair of external connection terminals can be electrically disconnected from the piezoelectric vibrator by partially cutting off each of the pair of common wiring sections to form a disconnected section. This prevents the inspection terminals from being electrically short-circuited due to external factors, as can occur in conventional methods, when the piezoelectric vibration device is mounted and joined to an external circuit board. In this case, since the pair of common wiring sections are located on the other side of the insulating substrate in an area that does not overlap with the external connection terminals on the main surface, a portion of each of the pair of common wiring sections can be easily cut off to form a disconnected section, and there is no risk of damaging the external connection terminals during the cutting process.

[0011] Furthermore, since there is no need to form large inspection terminals, this does not hinder the miniaturization of piezoelectric vibration devices. In addition, since the common wiring section other than the inspection terminals and the divided section is covered with an insulating substrate film, when mounting the piezoelectric vibration device on an external circuit board, the inspection terminals will not be exposed as in conventional designs, thus preventing accidental short circuits of the inspection terminals. [Effects of the Invention]

[0012] According to the present invention, it is possible to easily inspect a piezoelectric vibrator, and when the piezoelectric vibrator is mounted and joined to an external circuit board after the inspection is completed, it is possible to prevent electrical short circuits caused by external factors from occurring at the inspection terminals. [Brief explanation of the drawing]

[0013] [Figure 1] This is a cross-sectional view of a piezoelectric vibration device according to the first embodiment of the present invention, along the line L1-L1. [Figure 2] This is a plan view of the piezoelectric vibration device in Figure 1 with the molding resin removed. [Figure 3] Figure 1 is a bottom view of the insulating substrate. [Figure 4] Figure 1 is a cross-sectional view of the piezoelectric vibration device along the line L2-L2. [Figure 5]It is a bottom view of an insulating substrate in a state where a part of each of a pair of common wiring portions of the piezoelectric vibration device of FIG. 1 is cut off. [Figure 6] It is a cross-sectional view taken along the line L2-L2 of the piezoelectric vibrator device of FIG. 5. [Figure 7] It is a circuit connection diagram of the piezoelectric vibration device of FIG. 1. [Figure 8] It is a circuit connection diagram after forming a dividing portion in the piezoelectric vibration device of FIG. 1. [Figure 9] It is a cross-sectional view of a piezoelectric vibration device according to a second embodiment of the present invention.

Mode for Carrying Out the Invention

[0014] <First Embodiment> The piezoelectric vibration device according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 8. Note that the A1-A2 axis and the B1-B2 axis in FIGS. 3 to 5 represent the same coordinate axes.

[0015] (Configuration) As shown in FIG. 1, the piezoelectric vibration device 1 includes an insulating substrate (corresponding to the “insulating substrate” of the present invention) 2, a piezoelectric vibrator (corresponding to the “piezoelectric vibrator” of the present invention) 3 and an IC chip (corresponding to the “integrated circuit element” of the present invention) 4 mounted on the upper surface (corresponding to the “one main surface” of the present invention) 2a of the insulating substrate 2, and a molded resin layer 5 molded on the upper surface 2a side of the insulating substrate 2 so as to cover the piezoelectric vibrator 3 and the IC chip 4. Here, the insulating substrate 2 is composed of a single insulating substrate formed with a metal foil pattern on a glass epoxy substrate, and the metal foil pattern will be described in detail later. Note that the molded resin layer 5 is preferably formed of a thermosetting resin such as an epoxy resin.

[0016] As shown in FIG. 1, the piezoelectric vibrator 3 includes a piezoelectric vibrating plate 31 having a substantially rectangular shape, a first sealing member 32, and a second sealing member 33. In the piezoelectric vibrator 3, the piezoelectric vibrating plate 31 and the first sealing member 32 are joined, and the piezoelectric vibrating plate 31 and the second sealing member 33 are joined to form a package having a substantially rectangular parallelepiped sandwich structure. That is, in the piezoelectric vibrator 3, the first sealing member 32 and the second sealing member 33 are joined to each of the main surfaces of the piezoelectric vibrating plate 31, so that an internal space S of the package shown by a dashed rectangle in FIG. 2 is formed, and the piezoelectric vibrating portion (not shown) of the piezoelectric vibrating plate 31 is sealed in this internal space in an airtight state. Then, the piezoelectric vibrator 3 and the IC chip 4 are mechanically joined to the upper surface 2a of the insulating substrate 2 by an insulating bonding material 6 such as an epoxy resin.

[0017] The piezoelectric vibrating plate 31 constituting the piezoelectric vibrator 3 is formed of a substantially rectangular parallelepiped-shaped AT-cut quartz plate formed from a single quartz plate and performing thickness-shear vibration, and includes a substantially rectangular vibrating portion in which a first excitation electrode and a second excitation electrode are formed at opposing positions on the first main surface on the upper surface side and the second main surface on the lower surface side, respectively. The vibrating portion of the piezoelectric vibrating plate 31 is surrounded by a thick outer frame portion with a gap formed by cutting, and the vibrating portion and the outer frame portion are connected by a connecting portion.

[0018] The first sealing member 32 has a substantially rectangular parallelepiped shape formed from a single quartz plate, like the piezoelectric vibrating plate 31, and the surface on the side joined to the piezoelectric vibrating plate 31 is formed as a flat and smooth surface (mirror finish), and an AT-cut quartz plate is used. Also, the second sealing member 33 has a substantially rectangular parallelepiped shape formed from a single quartz plate, like the first sealing member 32, and the surface on the side joined to the piezoelectric vibrating plate 31 is formed as a flat and smooth surface (mirror finish) and an AT-cut quartz plate is used.

[0019] As shown in Figures 1 and 2, the piezoelectric diaphragm 31 and the first sealing member 32 are stacked on top of each other, and the piezoelectric diaphragm 31 and the second sealing member 33 are also stacked on top of each other and diffusion-bonded to form the first and second seal paths 34a and 34b. The first and second seal paths 34a and 34b are formed in annular shape in plan view, and an internal space S is formed in which the vibrating portion of the piezoelectric diaphragm 31, including the first and second excitation electrodes, is hermetically sealed. This produces the sandwich-structure package shown in Figures 1 and 2.

[0020] As shown in Figure 2, L-shaped first to fourth external connection electrodes 32a, 32b, 32c, and 32d are formed in a counterclockwise direction in plan view at the four corners of the upper surface of the piezoelectric vibrator 3, i.e., the upper surface of the first sealing member 32. These external connection electrodes are, for example, the first external connection electrode 32a which is the output terminal of the piezoelectric vibrator 3, the third external connection electrode 32c which is the input terminal of the piezoelectric vibrator 3, and the second external connection electrode 32b and the fourth external connection electrode 32d which are the ground terminals.

[0021] Furthermore, an insulating base material film 7 is applied to the upper surface 2a and the lower surface (corresponding to the "other main surface" of the present invention) 2b of the insulating substrate 2, respectively. As shown in Figure 2, at the four corners of the upper surface 2a of the insulating substrate 2, the base material film 7 is peeled off and the surface of the insulating substrate 2 is cut out in a rectangular concave shape to form recesses 21a, 21b, 21c, and 21d. Furthermore, as shown in Figure 3, at the four corners of the lower surface 2b of the insulating substrate 2, the base material film 7 is peeled off and the surface of the insulating substrate 2 is cut out in a rectangular concave shape to form recesses 22a, 22b, 22c, and 22d. Here, for example, a highly transparent epoxy resin can be used as the base material film 7. Note that the base material film 7 may also be semi-transparent, as long as the inside of the base material film 7 on the lower surface 2b can be seen from the outside.

[0022] As shown in Figure 2, first and second piezoelectric vibrator mounting pads 23a and 23b are formed in the recesses 21a and 21b on the A2 side of the upper surface 2a of the insulating substrate 2, respectively. The first external connection electrode 32a, which is the output terminal of the piezoelectric vibrator 3 on the upper surface of the first sealing member 32, and the first piezoelectric vibrator mounting pad 23a are electrically connected by a wire W, and the third external connection electrode 32c, which is the input terminal of the piezoelectric vibrator 3 on the upper surface of the first sealing member 32, and the second piezoelectric vibrator mounting pad 23b are electrically connected by a wire W.

[0023] Pads 24a, 24b, and 24c for mounting the first to third ICs are formed in the recess 21d on the A1-B1 side of the upper surface 2a of the insulating substrate 2, and pads 24d, 24e, and 24f for mounting the fourth to sixth ICs are formed in the recess 21c on the A1-B2 side. These pads 24a to 24f for mounting the first to sixth ICs are, for example, the following terminals. Pad 24a for mounting the first IC is the oscillation input terminal on the input side of the excitation electrode, and the first external connection terminal 4a of the IC chip 4 is electrically connected by wire W. Pad 24b for mounting the second IC is the power supply terminal, and the second external connection terminal 4b of the IC chip 4 is electrically connected by wire W. Pad 24c for mounting the third IC is the output terminal, and the third external connection terminal 4c of the IC chip 4 is electrically connected by wire W. Pad 24d for mounting the fourth IC is the oscillation output terminal on the output side of the excitation electrode, and the fourth external connection terminal 4d of the IC chip 4 is electrically connected by wire W. Pad 24e for mounting the 5th IC is an output enable terminal, and the 5th external connection terminal 4e of the IC chip 4 is electrically connected by wire W. Pad 24f for mounting the 6th IC is a ground terminal, and the 6th external connection terminal 4f of the IC chip 4 is electrically connected by wire W.

[0024] As shown in Figure 3, rectangular first to fourth external connection terminals 25a, 25b, 25c, and 25d are formed in the recesses 22a to 22d at the four corners of the lower surface 2b of the insulating substrate 2. These first to fourth external connection terminals 25a to 25d are used when mounting the piezoelectric vibration device 1 to other equipment (such as a wiring board), and are, for example, the following terminals: the first external connection terminal 25a is a power terminal, the third external connection terminal 25c is a ground terminal, the second external connection terminal 25b is an output enable terminal, and the fourth external connection terminal 25d is an output terminal. These external connection terminals 25a to 25d and each pad 23a, 23b, 24a to 24f of the insulating substrate 2 are formed by copper plating on copper foil, nickel plating on top of that, palladium plating on top of that, and gold plating on the top.

[0025] A feature of the present invention is that, as shown in Figure 3, a pair of rectangular inspection terminals 26a, 26b and a pair of common wiring sections 27a, 27b are provided on the lower surface (the other main surface) 2b of the insulating substrate 2 at a position that does not overlap with the external connection terminals 25a to 25d. One inspection terminal 26a is connected to a third external connection terminal 25c, which is an earth terminal, via one of the common wiring sections 27a, and the other inspection terminal 26b is connected to a first external connection terminal 25a, which is a power supply terminal, via the other common wiring section 27b. The lower ends of vias 28a, 28b, which are formed by filling through holes that penetrate the insulating substrate 2 vertically with conductors, are connected to both inspection terminals 26a, 26b, respectively. Alternatively, through holes with conductors attached to their interiors may be formed instead of vias 28a, 28b.

[0026] Furthermore, as shown in Figure 2, on the upper surface (one main surface) 2a of the insulating substrate 2, the pad for mounting the fourth IC 24d, which is the oscillation output terminal on the output side of the excitation electrode, and the pad for mounting the second piezoelectric vibrator 23b are connected by a first connection wiring section 29a extending in the A1-A2 direction. The pad for mounting the second piezoelectric vibrator 23b is connected to the third external connection electrode 32c, which is the input terminal of the piezoelectric vibrator 3, by a wire W. Thus, the pad for mounting the fourth IC 24d and the third external connection electrode 32c are connected via the first connection wiring section 29a, the pad for mounting the second piezoelectric vibrator 23b, and the wire W.

[0027] Furthermore, on the upper surface (one main surface) 2a of the insulating substrate 2, the first IC mounting pad 24a, which is the oscillation input terminal on the input side of the excitation electrode, and the first piezoelectric vibrator mounting pad 23a are connected by a second connection wiring section 29b extending in the A1-A2 direction, and the first piezoelectric vibrator mounting pad 23a is connected to the first external connection electrode 32a, which is the output terminal of the piezoelectric vibrator 3, by a wire W. Thus, the first IC mounting pad 24a and the first external connection electrode 32a are connected via the second connection wiring section 29b, the first piezoelectric vibrator mounting pad 23a, and the wire W.

[0028] Furthermore, as shown in Figures 3 and 4, the upper end of via 28a is connected to an extension extending in the direction B1 from the middle of the first connection wiring section 29a, and the upper end of via 28b is connected to an extension extending in the direction B2 from the middle of the second connection wiring section 29b. As a result, the third external connection terminal 25c on the lower surface 2b side of the insulating substrate 2 is connected to the third external connection electrode 32c via one common wiring section 27a, one inspection terminal 26a, via 28a, the first connection wiring section 29a on the upper surface 2a side of the insulating substrate 2, the second piezoelectric vibrator mounting pad 23b, and wire W. Also, the first external connection terminal 25a on the lower surface 2b side of the insulating substrate 2 is connected to the first external connection electrode 32a via the other common wiring section 27b, the other inspection terminal 26b, via 28b, the second connection wiring section 29b on the upper surface 2a side of the insulating substrate 2, the first piezoelectric vibrator mounting pad 23a, and wire W.

[0029] At this time, the upper ends of the first and second connection wiring sections 29a, 29b and vias 28a, 28b on the upper surface 2a side of the insulating substrate 2, and the lower ends of the vias 28a, 28b, inspection terminals 26a, 26b and common wiring sections 27a, 27b on the lower surface 2b side of the insulating substrate 2 are covered by the base material film 7.

[0030] In a piezoelectric vibration device 1 having such a configuration, when inspecting the characteristics of the piezoelectric vibrator 3 before actually using the piezoelectric vibration device 1, the piezoelectric vibrator 3 can be inspected via the first and third external connection terminals 25a and 25c shown in Figure 3, which are exposed on the lower surface 2b of the insulating substrate 2. At this time, the first and third external connection terminals 25a and 25c are power terminals and ground terminals, respectively, and are unrelated to the fifth IC mounting pad 24e, which is an output terminal of the IC chip 4. Therefore, the characteristics of the piezoelectric vibrator 3 can be inspected without being affected by output noise generated from the IC chip 4 during the inspection.

[0031] Then, once the characteristic testing of the piezoelectric vibrator 3 is complete, as shown in Figures 5 and 6, the first and third external connection terminals 25a and 25c can be electrically isolated from the piezoelectric vibrator 3 by cutting off a portion of the common wiring sections 27a and 27b together with the substrate film 7 using laser irradiation, thereby forming the separated sections Da and Db. Since the piezoelectric vibrator 3 and IC chip 4 are not placed (not superimposed) on the upper surface 2a, which is the main surface of the insulating substrate 2 opposite to the separated sections Da and Db, the thermal shock caused by the laser irradiation for forming the separated sections Da and Db does not directly affect the mounted components.

[0032] Incidentally, the circuit diagram of the piezoelectric vibration device 1 is as shown in Figures 7 and 8. Figure 7 shows the wiring state before the formation of the divided sections Da and Db, and Figure 8 shows the wiring state after the formation of the divided sections Da and Db. In Figures 7 and 8, C1 and C2 are capacitors provided between the input and output sides of the piezoelectric vibrator 3 and ground, respectively. AMP1 is an inverter amplifier connected in parallel to the series circuit of the limiting resistor RD and the piezoelectric vibrator 3. AMP2 is an inverter amplifier connected in series to amplifier AMP1. RF is a feedback resistor connected in parallel to amplifier AMP1. OUT is the output terminal of amplifier AMP2. Vd is the power supply. Here, excluding the piezoelectric vibrator 3, the oscillation amplification circuit including inverter amplifiers AMP1 and AMP2, resistors RD and RF, and load capacitors C1 and C2 is composed of an IC chip 4.

[0033] At this time, as shown in Figure 7, the input terminal of the piezoelectric vibrator 3 is connected to the power supply, and the output terminal of the piezoelectric vibrator 3 is connected to ground (earth). After the inspection is completed, when the separation sections Da and Db are formed by laser light irradiation, as shown in Figure 8, the output terminal of the piezoelectric vibrator 3 and the first external connection terminal 25a are electrically isolated, and the input terminal of the piezoelectric vibrator 3 and the third external connection terminal 25c are electrically isolated. Therefore, when the piezoelectric vibration device 1 is mounted on an external circuit board and joined, it is possible to prevent the inspection terminals 26a and 26b from being electrically short-circuited due to external factors. If the characteristics of the piezoelectric vibrator 3 are not to be inspected, a portion of both common wiring sections 27a and 27b is cut off together with the base film 7 to form the separation sections Da and Db.

[0034] Therefore, according to the first embodiment described above, the first and third external connection terminals 25a and 25c exposed on the lower surface of the insulating substrate 2 can be used to inspect the characteristics of the piezoelectric vibrator 3. After the inspection is completed, the first and third external connection terminals 25a and 25c can be electrically disconnected from the piezoelectric vibrator 3 by partially cutting off a pair of common wiring sections 27a and 27b on the lower surface of the insulating substrate 2 by laser irradiation or the like to form separated sections Da and Db. This prevents the inspection terminals from being electrically short-circuited due to external factors when the piezoelectric vibration device 1 is mounted and joined to an external circuit board.

[0035] Furthermore, since the pair of common wiring sections 27a and 27b are located in an area of ​​the lower surface 2b of the insulating substrate that does not overlap with the respective external connection terminals 25a to 25d, a portion of both common wiring sections 27a and 27b can be easily cut to form divided sections Da and Db, and there is no risk of damaging the external connection terminals 25a to 25d during the cutting process.

[0036] Furthermore, the first and third external connection terminals 25a and 25c, which connect the pair of common wiring sections 27a and 27b, are power terminals and ground terminals, respectively, and are unrelated to the fifth IC mounting pad 24e, which is the output terminal of the IC chip 4. Therefore, the DLD characteristics of the piezoelectric vibrator 3 can be tested without being affected by output noise generated from the IC chip 4.

[0037] Furthermore, since there is no need to form particularly large inspection terminals 26a and 26b, this does not hinder the miniaturization of the piezoelectric vibration device 1. In addition, since the common wiring sections 27a and 27b other than both inspection terminals 26a and 26b and the divided sections Da and Db are covered with an insulating base material film 7, the risk of accidental short circuits of the inspection terminals can be prevented.

[0038] Furthermore, since the molded resin layer 5 covers the piezoelectric vibrator 3 and the IC chip 4, the piezoelectric vibrator 3 and the IC chip 4 can be protected.

[0039] Furthermore, by providing first to fourth external connection terminals 25a to 25d connected only to the IC chip at the four corners of the insulating substrate 2, it is possible to miniaturize the device without increasing the number of external connection terminals, while securing the large-area external connection terminals essential for the piezoelectric vibration device 1, and eliminating the risk of short circuits between external connection terminals. <Second Embodiment> A piezoelectric vibration device 1A according to a second embodiment of the present invention will be described with reference to Figure 9. In Figure 9, the same reference numerals as in Figure 1 indicate the same or equivalent components. Furthermore, the following description will also refer to Figures 1 to 6.

[0040] The piezoelectric vibration device 1A according to the second embodiment differs from the first embodiment in that, instead of the piezoelectric vibrator 3 having a three-layer stacked structure in which piezoelectric vibration elements are mounted on a substrate 2 as in the first embodiment, as shown in Figure 9, a piezoelectric vibrator having a pair of excitation electrodes is housed in a ceramic package 36, and the opening surface of the package 36 is sealed with a lid member 37 to form a piezoelectric vibrator 3A, and this piezoelectric vibrator 3A is mounted on the upper surface 2a, which is one of the main surfaces of the insulating substrate 2, with the lid member 37 of the piezoelectric vibrator 3A facing downwards. Note that 38 in Figure 9 are four external connection electrodes of the piezoelectric vibrator 3A provided on the side of the package 36 opposite to the lid member 37.

[0041] Here, although not shown in Figure 9, in the piezoelectric vibration device 1A of the second embodiment, similar to the first embodiment, a pair of inspection terminals and a pair of common wiring sections are provided on the lower surface (the other main surface) 2b of the insulating substrate in a position that does not overlap with the external connection terminals 25a to 25d. The pair of common wiring sections are connected to a pair of excitation electrodes of a piezoelectric vibrator mounted on the upper surface (the other main surface) 2a of the insulating substrate 2, and the pair of inspection terminals are connected to the external connection terminals 25a and 25c, respectively. The substrate film 7 covers both surfaces 2a and 2b of the insulating substrate 2, including both inspection terminals and both common wiring sections.

[0042] Furthermore, two of the four external connection electrodes 38 are connected by wires W to the first and second piezoelectric vibrator mounting pads 23a and 23b on the insulating substrate 2, similar to the first and third external connection electrodes 32a and 32c in the first embodiment. They are further connected to the first and third external connection terminals 25a and 25c on the lower surface 2b side of the insulating substrate 2 via connection wiring sections 29a and 29b, vias 28a and 28b, inspection terminals 26a and 26b, and common wiring sections 27a and 27b. After the characteristics of the piezoelectric vibrator 3A are tested, a portion of each of the pair of common wiring sections 27a and 27b is cut off together with the base film 7 to form separated sections Da and Db. This disconnects the electrical connection between the first and third external connection terminals 25a and 25c and the external connection electrodes 38 of the piezoelectric vibrator 3A, preventing the inspection terminals from being electrically short-circuited due to external factors when the piezoelectric vibration device 1A is mounted and bonded to the external circuit board.

[0043] Therefore, according to the second embodiment, even if the piezoelectric vibration device 1A is a surface-mount type in a ceramic package, the same effects as those of the first embodiment described above can be obtained.

[0044] It should be noted that the present invention is not limited to the above-described configuration, and various design modifications can be made within the scope of the matters described in the claims.

[0045] For example, in the embodiment described above, a case in which a glass epoxy substrate is used for the insulating substrate 2 was explained, but other materials other than glass epoxy may be used for the insulating substrate 2.

[0046] Furthermore, the insulating substrate 2 is not limited to a single-layer configuration as in the embodiment described above, but may also be configured by stacking multiple substrates. In this case, stacking the insulating substrates has the advantage of increasing the density of the wiring.

[0047] Furthermore, although the above-described embodiments described a case in which the piezoelectric vibrator 3 and IC chip 4 mounted on the insulating substrate 2 are molded by the molded resin layer 5, the present invention can be similarly applied to non-molded piezoelectric vibration devices to obtain the same effects as the above-described embodiments.

[0048] Furthermore, although the above-described embodiment described a case in which the piezoelectric vibrators 3 and 3A and the piezoelectric vibrator mounting pads 23a and 23b on the insulating substrate 2 are connected by wire W, they may also be connected by solder.

[0049] Furthermore, in the first embodiment described above, the shape of the vibrating part of the piezoelectric vibration element is a rectangular AT cut, but it is not limited to this, and for example, it may be a rectangular SC cut or a tuning fork shape.

[0050] Furthermore, the piezoelectric oscillators 3 and 3A may be CMOS type or differential output type. In addition, the IC chip 4 may be equipped with a temperature compensation circuit.

[0051] Furthermore, the above-described embodiments are applicable to both VCXO (Voltage Controlled Crystal Oscillator) and TCXO (Temperature Compensated Crystal Oscillator).

[0052] Furthermore, the present invention can be applied not only when four external connection terminals are provided on the lower surface 2b of the insulating substrate 2, as described above, but also when five or more external connection terminals are provided. In this case, the external connection terminals connecting the pair of common wiring sections 27a and 27b can be connected to the first and third external connection terminals 25a and 25c, which are the power terminal and ground terminal respectively, as described above, as well as to the other external connection terminals excluding the output terminals of the IC chip 4.

[0053] The present invention is widely applicable to piezoelectric vibration devices comprising an insulating substrate and a piezoelectric vibrator and integrated circuit elements mounted on the insulating substrate. [Explanation of symbols]

[0054] 1,1A: Piezoelectric vibration device 2: Insulating substrate 2a: Top surface (one of the main surfaces) 2b: Bottom surface (the other main surface) 3,3A: Piezoelectric vibrator 31: Piezoelectric vibration element 4: IC chip (integrated circuit element) 7: Base film 25a, 25b, 25c, 25d: External connection terminals 26a, 26b: Test terminals 27a, 27b: Common wiring section Da, Db: Divided section

Claims

[Claim 1] A piezoelectric vibration device comprising an insulating substrate and a piezoelectric vibrator and an integrated circuit element mounted on one main surface of the insulating substrate, The piezoelectric vibrator is, A piezoelectric vibrating element having a pair of excitation electrodes, The piezoelectric vibration element is enclosed by a sealing member that seals it in an airtight state, The aforementioned integrated circuit element is The piezoelectric vibration element comprises an oscillation amplification circuit to which the input terminal and output terminal are connected to the input side and output side, respectively, of the pair of excitation electrodes. The insulating substrate is The aforementioned one main surface and, The other main surface is provided with at least one pair of external connection terminals connected to the integrated circuit element, On the other main surface, at a position not overlapping with the pair of external connection terminals, at least a pair of inspection terminals are provided and connected to the pair of excitation electrodes of the piezoelectric vibrator, The other main surface is provided in a position that does not overlap with the pair of external connection terminals, and includes at least one pair of common wiring sections that connect the pair of test terminals to the pair of external connection terminals, An insulating substrate film covers the surface of each of the two main surfaces, including the pair of inspection terminals and the pair of common wiring sections, except for a portion of the two main surfaces. Equipped with, The pair of common wiring sections are, It comprises a segmented portion that is cut off together with the base film at at least one location. A piezoelectric vibration device characterized by the following features.

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