Piezoelectric vibration device

Abstract

The inspection terminals for testing the characteristics of the piezoelectric vibration device are exposed on the side end face of the molded resin at the boundary between the insulating substrate and the molded resin, allowing for easy inspection of the piezoelectric vibrator without causing a short circuit at the inspection terminals. [Solution] The piezoelectric vibrator-side conductor plates 8a and 8b are positioned so as not to overlap with the external connection terminals on the lower surface of the insulating substrate 2. The piezoelectric vibrator-side conductor plates 8a and 8b are connected to the piezoelectric vibrator 3 via a group of wiring patterns on the upper surface 2a of the insulating substrate 2. The side end faces of the piezoelectric vibrator-side conductor plates 8a and 8b are exposed to the outside from the boundary between the insulating substrate 2 and the molded resin 5. This allows the characteristics of the piezoelectric vibrator 3 to be tested using the exposed piezoelectric vibrator-side conductor plates 8a and 8b.

Description

Technical Field

[0001] The present invention relates to a piezoelectric vibration device including an insulating substrate, a piezoelectric vibrator and an integrated circuit element mounted on one main surface of the insulating substrate, and a molding resin covering the piezoelectric vibrator and the 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 conduction means that conducts to the electrode pad and conducts between the inner surface and the outer surface of the package. A wiring pattern that can be cut is used to connect an adjustment terminal provided on the outer surface of the package to the conduction means.

[0003] Also, the piezoelectric vibration device described in Patent Document 2 has 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 connected to the wiring pattern and 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 molding portion so as to include at least the piezoelectric vibrator. 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. During inspection, the insulating resin in the insulating region covering the inspection terminal is peeled off 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] However, since the adjustment terminals and wiring patterns in the configuration described in Patent Document 1 remain as they are, adjustment terminals and wiring patterns unrelated to the original operation of the piezoelectric vibration device remain on the package surface. This raises the risk of short-circuiting the adjustment terminals when the piezoelectric vibration device is mounted and connected to an external wiring board, which could adversely affect the device's performance. Furthermore, while these adjustment terminals can be used, for example, as test terminals for characteristic testing of the piezoelectric vibration device, they also remain on the package surface when used as test terminals, thus posing the same risk of short-circuiting as described above.

[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 mold 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 mold 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 and joined to an external wiring board, and there is a problem that this may adversely affect the performance of the piezoelectric vibration device, similar to the technology described in Patent Document 1.

[0007] The present invention has been made in view of the above problems, and its first objective is to make it possible to easily inspect a piezoelectric vibrator without causing a short circuit of the inspection terminal, by exposing the inspection terminal for inspecting the characteristics of a piezoelectric vibration device at the side end surface of the molded resin, at the boundary between the insulating substrate and the molded resin.

[0008] Furthermore, a second objective of the present invention is to expose terminals, which can be used for adjusting or writing data to integrated circuit elements of a piezoelectric vibration device, on the side end face of the molded resin at the boundary between the insulating substrate and the molded resin, thereby facilitating adjustment of the oscillation characteristics of integrated circuit elements and / or data writing without causing short circuits of these terminals. [Means for solving the problem]

[0009] To achieve the first objective described above, the piezoelectric vibration device according to the present invention comprises an insulating substrate, a piezoelectric vibrator and an integrated circuit element mounted on one main surface of the insulating substrate, and a molded resin covering the piezoelectric vibrator and the integrated circuit element, wherein the piezoelectric vibrator comprises a piezoelectric vibration element having a pair of excitation electrodes and a sealing member for sealing the piezoelectric vibration element in an airtight 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, the insulating substrate comprises one main surface and the other main surface on which external connection terminals are provided, and a connecting conductor plate connected to the piezoelectric vibrator and / or the integrated circuit element is arranged at a position on the one main surface of the insulating substrate that does not overlap with the external connection terminals and is embedded in the molded resin, and the side end surface of the connecting conductor plate is exposed to the outside from the boundary portion between the insulating substrate and the molded resin.

[0010] With this configuration, the connecting conductor plate is positioned so as not to overlap with the external connection terminals on the other main surface of the insulating substrate, and the side end face of the connecting conductor plate is exposed to the outside from the boundary between the insulating substrate and the molded resin. Therefore, the exposed connecting conductor plate can be used to perform characteristic testing of the piezoelectric vibrator and / or adjustment and data writing of integrated circuit elements.

[0011] In this configuration, since the connecting conductor plate does not overlap with the external connection terminals of the insulating substrate, there is no risk of electrical short circuits occurring between the connecting conductor plate and the external connection terminals when the piezoelectric vibration device is mounted and joined to the external wiring board. Furthermore, because the connecting conductor plate is exposed to the outside from the boundary between the insulating substrate and the molded resin, there is no need to separately provide external connection terminals on the underside of the piezoelectric vibration device for characteristic testing of the piezoelectric vibrator and / or adjustment of integrated circuit elements or data writing, thereby preventing the piezoelectric vibration device from becoming larger.

[0012] Furthermore, the connecting conductor plate may include two piezoelectric vibrator-side conductor plates that are connected to the pair of excitation electrodes of the piezoelectric vibrator via a wiring pattern formed on one of the main surfaces of the insulating substrate. Furthermore, the connecting conductor plate may include two integrated circuit element-side conductor plates that are connected to the adjustment terminal and / or data writing terminal of the integrated circuit element via a wiring pattern formed on one of the main surfaces of the insulating substrate.

[0013] With this configuration, the characteristics of the piezoelectric oscillator and / or the adjustment and data writing of integrated circuit elements can be performed using the exposed connecting conductor plate.

[0014] Furthermore, the connecting conductor plate is preferably made of metal with a thickness of 100 μm or more.

[0015] This design allows for the use of a metal conductor plate with a thickness of 100 μm or more, making it easier to procure conductor materials and simplifying processing. The thickness of 100 μm or more ensures reliable electrical contact with the conductor plate. Furthermore, because it is made of metal, burrs are generated on the conductor plate during processing to expose it, increasing the contact area with the conductor plate and enabling more reliable contact.

[0016] Furthermore, the connecting conductor plate may have, in the portion embedded in the molded resin, a narrow region in the width direction and / or a thin region in the thickness direction.

[0017] With this configuration, the molding resin is interlocked with the thin portion of the connecting conductor plate during molding, thus preventing the connecting conductor plate from coming loose from the molding resin.

[0018] Furthermore, the insulating substrate is provided with two piezoelectric vibrator-side conductor plates, which serve as connecting conductor plates connected to a pair of excitation electrodes of the piezoelectric vibrator, and two integrated circuit element-side conductor plates, which serve as connecting conductor plates connected to the adjustment terminals and / or data writing terminals of the integrated circuit element, at positions on one of the main surfaces of the insulating substrate that do not overlap with the external connection terminals. The insulating substrate is substantially rectangular, and the piezoelectric vibrator-side conductor plates and the integrated circuit element-side conductor plates are preferably arranged symmetrically with respect to a line connecting the centers of a pair of long sides in the rectangle of the insulating substrate.

[0019] This configuration allows for the simultaneous formation of multiple piezoelectric vibrator-side conductor plates and integrated circuit element-side conductor plates on a single insulating substrate. When these plates are then separated into individual piezoelectric vibration devices, the piezoelectric vibrator-side conductor plates and integrated circuit element-side conductor plates can be easily exposed on the sides of the molded resin, resulting in excellent mass productivity.

[0020] Furthermore, the method for manufacturing a piezoelectric vibration device according to the present invention includes the steps of preparing to arrange a plurality of sets of piezoelectric vibrators, each comprising a piezoelectric vibrator having a pair of excitation electrodes and a sealing member for sealing the piezoelectric vibrator, and an integrated circuit element comprising an oscillation amplification circuit, in at least one row on one main surface of a single insulating substrate; connecting the piezoelectric vibrator and integrated circuit element of the set to a wiring pattern including a plurality of pads provided on the one main surface of the insulating substrate for each set of piezoelectric vibrator and integrated circuit element, thereby connecting the integrated circuit element of the set to an external connection terminal provided on the other main surface of the insulating substrate for each set, and connecting the integrated circuit element of the set to the input and output sides of the pair of excitation electrodes of the piezoelectric vibrator of the set; and placing the piezoelectric vibrator of the set in a predetermined region on the insulating substrate between the piezoelectric vibrator of the set and the integrated circuit element of the set adjacent to the piezoelectric vibrator, at a position that does not overlap with the external connection terminal on the one main surface, and in that region. The present invention is characterized by comprising the steps of: arranging a plurality of conductive members, each having both ends electrically and mechanically joined, on the upper surface of the wiring pattern connected to the vibrator and on the upper surface of the wiring pattern connected to a set of integrated circuit elements adjacent to the piezoelectric vibrator; covering one main surface of the insulating substrate, each set of piezoelectric vibrators and integrated circuit elements, and the plurality of conductive plates with a molding resin, with each set of piezoelectric vibrators and integrated circuit elements connected to the wiring pattern of each set of the insulating substrate; and cutting the insulating substrate and the molding resin at a cutting surface that overlaps with the conductive member between the piezoelectric vibrator of the set and the integrated circuit element of the set adjacent to the piezoelectric vibrator, thereby separating the piezoelectric vibration device, on which the piezoelectric vibrator and integrated circuit element are mounted on the insulating substrate, into individual pieces for each set, and exposing the side end faces of the conductive members at both cutting surfaces of the individualized piezoelectric vibration device.

[0021] According to such a configuration, a plurality of piezoelectric vibrators and integrated circuit elements are arranged in a row on one insulating substrate, a plurality of conductive members are formed, and after being molded with a mold resin, the mold resin is cut at a predetermined cut surface to individualize the piezoelectric vibration device. On the cut surfaces on both sides of the individualized piezoelectric vibration device, a piezoelectric vibrator side conductor plate and an integrated circuit element side conductor plate formed by cutting one conductive member can be respectively exposed.

Advantages of the Invention

[0022] According to the present invention, an inspection terminal for inspecting the characteristics of a piezoelectric vibration device is exposed at a side end surface of the mold resin at a boundary portion between the insulating substrate and the mold resin, and the inspection of the piezoelectric vibrator can be easily performed without causing a short circuit of the inspection terminal. Further, terminals that can be used for adjustment or data writing of, for example, an integrated circuit element of the piezoelectric vibration device are exposed at a side end surface of the mold resin at a boundary portion between the insulating substrate and the mold resin, and adjustment of the oscillation characteristics of the integrated circuit element and data writing can be easily performed without causing a short circuit of these terminals.

Brief Description of the Drawings

[0023] [Figure 1] It is a cross-sectional view of the piezoelectric vibration device according to the first embodiment of the present invention taken along line L1-L1. [Figure 2] It is a plan view of the piezoelectric vibration device of FIG. 1 in a state where the mold resin is removed. [Figure 3] It is a bottom view of the insulating substrate of FIG. 1. [Figure 4] It is a left side view of the piezoelectric vibration device of FIG. 1. [Figure 5] It is a right side view of the piezoelectric vibration device of FIG. 1. [Figure 6] (a) and (b) are a plan view and a front view in different states during the manufacture of the piezoelectric vibrator device of FIG. 1. [Figure 7] It is a view showing the conductive member used in FIG. 6. [Figure 8] It is a partial enlarged view of FIG. 4. [Modes for carrying out the invention]

[0024] A piezoelectric vibration device according to one embodiment of the present invention will be described with reference to Figures 1 to 8. Figure 1 is a cross-sectional view along the line L1-L1 in Figure 2, and the A1-A2 axis and B1-B2 axis in Figures 2 and 3 represent the same coordinate axes.

[0025] (composition) As shown in Figure 1, the piezoelectric vibration device 1 comprises 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 5 that molds 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 made of a single insulating substrate in which a metal foil pattern is formed on a glass epoxy substrate, and the metal foil pattern will be described in detail later. It is preferable that the molded resin 5 be formed from a thermosetting resin such as epoxy resin.

[0026] As shown in Figure 1, the piezoelectric vibrator 3 comprises a piezoelectric diaphragm (corresponding to the "piezoelectric vibration element" in this invention) 31, each having a substantially rectangular shape, a first sealing member 32, and a second sealing member 33. In the piezoelectric vibrator 3, the piezoelectric diaphragm 31 and the first sealing member 32 are joined together, and the piezoelectric diaphragm 31 and the second sealing member 33 are joined together to form a substantially rectangular parallelepiped sandwich structure package. That is, in the piezoelectric vibrator 3, the first sealing member 32 and the second sealing member 33 are joined to each of the two main surfaces of the piezoelectric diaphragm 31, forming an internal space S of the package shown by the dashed rectangle in Figure 2, and the piezoelectric vibrating portion (not shown) of the piezoelectric diaphragm 31 is sealed in an airtight state within this internal space. The piezoelectric vibrator 3 and the IC chip 4 are then mechanically joined to the upper surface 2a of the insulating substrate 2 by an insulating bonding material 6, such as epoxy resin. The first and second sealing members 32 and 33 correspond to the "sealing members" in the present invention.

[0027] The piezoelectric vibrator 3 comprises a piezoelectric diaphragm 31, which is made of an AT-cut quartz plate formed from a single quartz plate and has a roughly rectangular parallelepiped shape that performs thickness-sliding vibration. It has a roughly rectangular vibrating section in which a first excitation electrode and a second excitation electrode are formed at opposing positions on the upper and lower main surfaces. The vibrating section of the piezoelectric diaphragm 31 is surrounded by a thick outer frame with a gap created by a cutout, and the vibrating section and the outer frame are connected by a connecting section. Here, the first and second excitation electrodes correspond to the "pair of excitation electrodes" of the present invention.

[0028] The first sealing member 32, like the piezoelectric diaphragm 31, has a substantially rectangular parallelepiped shape formed from a single quartz plate, and the side that is joined to the piezoelectric diaphragm 31 is formed as a flat, smooth surface (mirror finish), and an AT-cut quartz plate is used. The second sealing member 33, like the first sealing member 32, has a substantially rectangular parallelepiped shape formed from a single quartz plate, and the side that is joined to the piezoelectric diaphragm 31 is formed as a flat, smooth surface (mirror finish), and an AT-cut quartz plate is used.

[0029] 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.

[0030] 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. Of these external connection electrodes 32a to 32d, for example, the first external connection electrode 32a is the output terminal of the piezoelectric vibrator 3, the third external connection electrode 32c is the input terminal of the piezoelectric vibrator 3, and the second external connection electrode 32b and the fourth external connection electrode 32d are ground terminals.

[0031] 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. 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.

[0032] 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.

[0033] Pads 24a, 24b, 24c, and 24d for mounting the first to fourth ICs are formed in the recess 21d on the A1-B1 side of the upper surface 2a of the insulating substrate 2, and pads 24e, 24f, 24g, and 24h for mounting the fifth to eighth ICs are formed in the recess 21c on the A1-B2 side. These pads 24a to 24h for mounting the first to eighth 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 data writing terminal, and the fourth external connection terminal 4d of the IC chip 4 is electrically connected by wire W. The fifth IC mounting pad 24e is the oscillation output terminal on the output side of the excitation electrode, and the fifth external connection terminal 4e of the IC chip 4 is electrically connected by wire W. The sixth IC mounting pad 24f is the output enable terminal, and the sixth external connection terminal 4f of the IC chip 4 is electrically connected by wire W. The seventh IC mounting pad 24g is a ground terminal that is not used for any purpose, and the seventh external connection terminal 4g of the IC chip 4 is electrically connected by wire W. The eighth IC mounting pad 24h is an adjustment terminal for characteristic adjustment, and the eighth external connection terminal 4h of the IC chip 4 is electrically connected by wire W.

[0034] 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 an external 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 24h 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.

[0035] A feature of the present invention is that, as shown in Figure 2, on the upper surface (one main surface) 2a of the insulating substrate 2, rectangular first and second joining wiring sections 26a and 26b are provided side by side from the B2 side to the B1 side along the short side on the A2 side of the rectangle of the insulating substrate 2, and rectangular third and fourth joining wiring sections 26c and 26d are provided side by side from the B2 side to the B1 side along the short side on the A1 side. Here, the first joining wiring section 26a and the second joining wiring section 26b are arranged approximately symmetrically with respect to a line connecting the centers of opposing short sides of the rectangle of the insulating substrate 2, and similarly, the third joining wiring section 26c and the fourth joining wiring section 26d are also arranged approximately symmetrically with respect to a line connecting the centers of opposing short sides of the rectangle of the insulating substrate 2, and furthermore, the first and second joining wiring sections 26a and 26b and the third and fourth joining wiring sections 26c and 26d are arranged approximately symmetrically with respect to a line connecting the centers of opposing long sides of the rectangle of the insulating substrate 2.

[0036] Furthermore, as shown in Figure 2, on the upper surface (one main surface) 2a of the insulating substrate 2, the fifth IC mounting pad 24e, which is the oscillation output terminal on the output side of the excitation electrode, and the second piezoelectric vibrator mounting pad 23b are connected by a first connection wiring section 27a that extends in the A1-A2 direction along the long side of the insulating substrate 2 on the B2 side. The fifth IC mounting pad 24e and the third external connection electrode 32c of the piezoelectric vibrator 3 are connected via the first connection wiring section 27a, the second piezoelectric vibrator mounting pad 23b, and the wire W.

[0037] Furthermore, as shown in Figure 2, on the upper surface (one main surface) 2a of the insulating substrate 2, the first IC mounting pad 24a and the first piezoelectric vibrator mounting pad 23a, which are oscillation input terminals on the input side of the excitation electrode, are connected by a second connection wiring section 27b that extends in the A1-A2 direction along the long side of the insulating substrate 2 on the B1 side. The first IC mounting pad 24a and the first external connection electrode 32a of the piezoelectric vibrator 3 are connected via the second connection wiring section 27b, the first piezoelectric vibrator mounting pad 23a, and the wire W.

[0038] Furthermore, the A2-side end of the first connecting wiring section 27a extends in the A2 direction, and this extended portion is connected to the first joining wiring section 26a. Similarly, the A2-side end of the second connecting wiring section 27b extends in the A2 direction and is connected to the second joining wiring section 26b.

[0039] Furthermore, as shown in Figure 2, on the upper surface (one main surface) 2a of the insulating substrate 2, the eighth IC mounting pad 24h and the third bonding wiring section 26c are connected via a short third connection wiring section 27c in the B1-B2 direction, and the third bonding wiring section 26c and the eighth external connection terminal 4h of the IC chip 4 are connected via the third connection wiring section 27c, the eighth IC mounting pad 24h, and the wire W.

[0040] Similarly, as shown in Figure 2, on the upper surface (one main surface) 2a of the insulating substrate 2, the fourth IC mounting pad 24d and the fourth bonding wiring section 26d are connected via a short fourth connection wiring section 27d in the B1-B2 direction, and the fourth bonding wiring section 26d and the fourth external connection terminal 4d of the IC chip 4 are connected via the fourth connection wiring section 27d, the fourth IC mounting pad 24d, and the wire W. Here, the pads 23a and 23b for mounting the first and second piezoelectric vibrators, the first and second joining wiring sections 26a and 26b and the first and second connecting wiring sections 27a and 27b, the pads 24a to 24c for mounting the first to third ICs and the pads 24e to 24g for mounting the fifth to seventh ICs, the pad 24d for mounting the fourth IC, the pad 24h for mounting the eighth IC, the third and fourth joining wiring sections 26c and 26d and the third and fourth connecting wiring sections 27c and 27d correspond to the "wiring pattern" in the present invention.

[0041] Furthermore, as shown in Figure 2, rectangular piezoelectric vibrator-side conductor plates 8a and 8b made of metal such as copper are electrically and mechanically joined to the first and second joint wiring sections 26a and 26b using conductive adhesive 9, respectively. Similarly, rectangular metal (copper) IC chip-side conductor plates 10a and 10b are electrically and mechanically joined to the third and fourth joint wiring sections 26c and 26d using conductive adhesive 9. Here, the piezoelectric vibrator-side conductor plates 8a and 8b correspond to the "piezoelectric vibrator-side conductor plate" and "connecting conductive plate" in the present invention, and the IC chip-side conductor plates 10a and 10b correspond to the "integrated circuit element-side conductor plate" and "connecting conductive plate" in the present invention. At this time, the piezoelectric vibrator-side conductor plates 8a and 8b and the IC chip-side conductor plates 10a and 10b are positioned so as not to overlap with the external connection terminals 25a to 25d on the lower surface 2b side of the insulating substrate 2.

[0042] As shown in Figure 2, the first and second joint wiring sections 26a and 26b are located on the A2 side (left side) of the piezoelectric vibrator 3. The first and second joint wiring sections 26a and 26b and the conductive adhesive 9 are covered by the molded resin 5 so that the A2 side edge (left edge) of the first and second joint wiring sections 26a and 26b and the conductive adhesive 9 on top of them are not exposed from the left end surface of the molded resin 5. As shown in Figures 2 and 4, the piezoelectric vibrator side conductor plates 8a and 8b are positioned so that only they are exposed from the left end surface of the molded resin 5 on the A2 side.

[0043] Furthermore, as shown in Figure 2, the third and fourth joint wiring sections 26c and 26d are located on the A1 side (right side) of the IC chip 4. The third and fourth joint wiring sections 26c and 26d and the conductive adhesive 9 are covered by the mold resin 5 so that the A1 side edge (right edge) of the third and fourth joint wiring sections 26c and 26d and the conductive adhesive 9 on top of them are not exposed from the left end face of the mold resin 5. As shown in Figures 2 and 5, the IC chip side conductor plates 10a and 10b are positioned so that only they are exposed from the right end face of the mold resin 5.

[0044] Furthermore, when performing characteristic testing of the piezoelectric vibrator 3, the piezoelectric vibrator 3 can be tested via the piezoelectric vibrator-side conductor plates 8a and 8b exposed on the side of the molded resin 5 on the A2 side in Figure 2. In addition, when adjusting the characteristics of the IC chip 4 and / or writing data to it, an external device can be connected to the adjustment terminal and / or data writing terminal of the IC chip 4 via the IC chip-side conductor plate 10a and / or IC chip-side conductor plate 10b exposed on the side of the molded resin 5 on the A1 side in Figure 2, and the characteristics of the IC chip 4 and / or data writing can be adjusted.

[0045] (Device manufacturing method) By the way, the manufacturing method of the piezoelectric vibration device 1 having the above-described configuration will be explained with reference to Figure 6.

[0046] As a preparation step, as shown in Figure 6, a long insulating substrate 2 is prepared in one direction (corresponding to the A1-A2 direction in Figure 2), and multiple sets of piezoelectric vibrators 3 and IC chips 4 are arranged in a row on the upper surface 2a of the insulating substrate 2, so that multiple sets of piezoelectric vibrators 3 and IC chips 4 are placed on a single insulating substrate 2. Note that pads 23a, 23b, 24a-24h, joining wiring sections 26a-26d, and connection wiring sections 27a-27d are formed on the upper surface 2a of the insulating substrate 2, but these are omitted from the illustration in Figure 6.

[0047] In the subsequent connection process, as shown in Figure 6, the piezoelectric vibrator 3 and IC chip 4 of each pair are connected by wire W to the wiring pattern including pads 23a, 23b, 24a~24h provided on the upper surface 2a of the insulating substrate 2, thereby connecting the IC chip 4 of each pair to the external connection terminals 25a~25d provided on the lower surface 2b of the insulating substrate 2 for each pair, and also connecting the IC chip 4 of each pair to the input and output sides of the first and second excitation electrodes of the piezoelectric vibrator 3.

[0048] Then, as part of the arrangement process, as shown in Figure 6, for each set of piezoelectric vibrators 3 and IC chips 4, a plurality of conductive metal members 11, with both ends electrically and mechanically joined, are placed in a predetermined area on the insulating substrate 2 between the set of piezoelectric vibrators 3 and the set of IC chips 4 adjacent to the piezoelectric vibrator 3, at a position that does not overlap with the external connection terminals 25a to 25d of the insulating substrate 2. These members are placed on the upper surfaces of the first and second joining wiring sections 26a and 26b connected to the set of piezoelectric vibrators 3, and on the upper surfaces of the third and fourth joining wiring sections 26c and 26d connected to the set of IC chips 4 adjacent to the piezoelectric vibrator 3.

[0049] At this time, the conductive member 11 is made of a metal such as copper, and as shown in Figure 7, it is constructed by connecting three rectangular parallelepiped sections 11a, 11b, and 11c by narrow sections 11d and 11e, which are regions where the width direction of the insulating substrate 2 is narrower than other parts. In the cutting process described below, the middle rectangular parallelepiped section 11b is cut at its central cut surface C, thereby separating it into piezoelectric vibrator side conductor plates 8a, 8b and IC chip side conductor plates 10a, 10b. Instead of 1d and 11e, the insulating substrate 2 may be thin-walled regions that are thin in the thickness direction, and it may have both narrow and thin-walled regions.

[0050] Next, as a molding process, as shown in Figure 6(a), with the piezoelectric vibrators 3 and IC chips 4 for each set connected to the wiring patterns of each set of insulating substrate 2, as shown in Figure 6(b), the upper surface 2a of the insulating substrate 2, including each set of piezoelectric vibrators 3 and IC chips 4, and a plurality of conductive members 11, is covered with molding resin 5.

[0051] Next, in the cutting process, the insulating substrate 2 and the molded resin 5 are cut by the blade of the cutting device along the cutting surface C that overlaps with the conductive member 11 shown by the dashed line in Figures 6(a) and (b), between the set of piezoelectric vibrators 3 and the set of IC chips 4 adjacent to the piezoelectric vibrators 3, thereby separating the piezoelectric vibration device 1, which consists of piezoelectric vibrators 3 and IC chips 4 mounted on the insulating substrate 2, into individual pieces for each set, and separating the conductive member 11 into piezoelectric vibrator-side conductor plates 8a, 8b and IC chip-side conductor plates 10a, 10b, thereby exposing the end faces of the piezoelectric vibrator-side conductor plates 8a, 8b and IC chip-side conductor plates 10a, 10b on both cutting surfaces C of the individual pieces of the piezoelectric vibration device 1.

[0052] Furthermore, the insulating substrate 2 is not limited to being elongated in one direction as described above, but may also have a shape that is elongated in the B1-B2 direction in Figure 2, and the piezoelectric vibration device 1 may be formed by arranging multiple sets of one piezoelectric vibrator 3 and one IC chip 4 as one set in the vertical and horizontal directions in a matrix, and then cutting them vertically and horizontally to make individual pieces.

[0053] According to the first embodiment described above, the left end face (left side in Figure 2) of the piezoelectric vibrator-side conductor plates 8a and 8b is exposed to the outside from the boundary between the insulating substrate 2 and the molded resin 5. Therefore, the characteristics of the piezoelectric vibrator 3 can be easily inspected using the exposed piezoelectric vibrator-side conductor plates 8a and 8b.

[0054] Furthermore, since the right-side end faces (right side in Figure 2) of the IC chip-side conductor plates 10a and 10b are exposed to the outside from the boundary between the insulating substrate 2 and the molded resin 5, the exposed IC chip-side conductor plates 10a and 10b can be used to easily perform adjustments such as temperature control and data writing of the IC chip 4.

[0055] Furthermore, since the piezoelectric vibrator-side conductor plates 8a, 8b and the IC chip-side conductor plates 10a, 10b do not overlap with the external connection terminals 25a to 25d of the insulating substrate 2, there is no risk of electrical short circuits occurring between the piezoelectric vibrator-side conductor plates 8a, 8b and the IC chip-side conductor plates 10a, 10b and the external connection terminals 25a to 25d when the piezoelectric vibration device 1 is mounted and joined to the external wiring board. In addition, since the piezoelectric vibrator-side conductor plates 8a, 8b and the IC chip-side conductor plates 10a, 10b are exposed to the outside from the boundary between the insulating substrate 2 and the molded resin 5, there is no need to separately provide external connection terminals for characteristic testing on the underside of the piezoelectric vibration device 1, thereby preventing an increase in the size of the piezoelectric vibration device 1.

[0056] Furthermore, by making the piezoelectric vibrator-side conductor plates 8a, 8b and the IC chip-side conductor plates 10a, 10b from metal (copper) with a thickness of 100 μm or more, the procurement of conductive members 11 becomes easier and processing can be simplified. The thickness of 100 μm or more ensures reliable electrical contact with the piezoelectric vibrator-side conductor plates 8a, 8b and the IC chip-side conductor plates 10a, 10b. Moreover, because they are made of metal (copper), when processing to expose the piezoelectric vibrator-side conductor plates 8a, 8b and the IC chip-side conductor plates 10a, 10b, burrs B as shown in Figure 8 are generated on the piezoelectric vibrator-side conductor plates 8a, 8b and the IC chip-side conductor plates 10a, 10b. This increases the contact area with the piezoelectric vibrator-side conductor plates 8a, 8b and the IC chip-side conductor plates 10a, 10b, enabling more reliable contact.

[0057] Furthermore, since the piezoelectric vibrator-side conductor plates 8a, 8b and the IC chip-side conductor plates 10a, 10b have thin-walled portions 11d, 11e in the portion of the insulating substrate 2 that is thinner in the thickness direction than other parts, as shown in Figure 7, the piezoelectric vibrator-side conductor plates 8a, 8b and the IC chip-side conductor plates 10a, 10b are molded with the molding resin 5 gripping the thin-walled portions 11d, 11e of the piezoelectric vibrator-side conductor plates 8a, 8b and the IC chip-side conductor plates 10a, 10b, thus preventing the piezoelectric vibrator-side conductor plates 8a, 8b and the IC chip-side conductor plates 10a, 10b from coming loose from the molding resin 5.

[0058] Furthermore, by arranging the piezoelectric vibrator-side conductor plates 8a, 8b and the IC chip-side conductor plates 10a, 10b in positions symmetrical with respect to a straight line connecting the centers of a pair of long sides of the insulating substrate 2, multiple piezoelectric vibrator-side conductor plates 8a, 8b and IC chip-side conductor plates 10a, 10b can be simultaneously formed on a single insulating substrate 2 and molded with molding resin 5. After forming multiple piezoelectric vibration devices 1, the piezoelectric vibration devices 1 can be individually separated, resulting in excellent mass productivity.

[0059] Furthermore, since the piezoelectric vibrator 3 and IC chip 4 are covered by the molded resin 5, the piezoelectric vibrator 3 and IC chip 4 can be protected.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] In the above-described embodiment, the case in which piezoelectric vibrator-side conductor plates 8a, 8b and IC chip-side conductor plates 10a, 10b are provided was explained. However, a configuration in which only piezoelectric vibrator-side conductor plates 8a, 8b are provided is also possible, as is a configuration in which only IC chip-side conductor plates 10a, 10b are provided.

[0064] 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.

[0065] Furthermore, in the above-described embodiment, metals other than copper, such as nickel silver, Kovar, and 42 alloy, may be used as the material for the piezoelectric vibrator side conductor plates 8a and 8b and the IC chip side conductor plates 10a and 10b. The material is not limited to these metals, but a thick film of silver paste for conductive adhesive 9 may also be used to form the conductor plates.

[0066] Furthermore, in the above-described embodiment, the case in which each pad 23a, 23b, 24a~24h of the insulating substrate 2 is connected to the piezoelectric vibrator 3 and the IC chip 4 by wires W was explained, but they may also be connected by solder.

[0067] Furthermore, in the above-described embodiment, 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, a rectangular SC cut or a tuning fork shape may also be used.

[0068] Furthermore, the piezoelectric oscillator 3 may be of the CMOS type or a differential output type. In addition, the IC chip 4 may be equipped with a temperature compensation circuit.

[0069] Furthermore, the above-described embodiments are applicable to both VCXO (Voltage Controlled Crystal Oscillator) and TCXO (Temperature Compensated Crystal Oscillator).

[0070] 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.

[0071] The present invention is widely applicable to piezoelectric vibration devices comprising an insulating substrate, a piezoelectric vibrator and an integrated circuit element mounted on one main surface of the insulating substrate, and a molded resin covering the piezoelectric vibrator and the integrated circuit element. [Explanation of symbols]

[0072] 1: Piezoelectric vibration device 2: Insulating substrate 2a: Top surface (one of the main surfaces) 2b: Bottom surface (the other main surface) 3: Piezoelectric vibrator 4: IC chip (integrated circuit element) 5: Molding resin 7: Base film 8a, 8b: Conductor plates on the piezoelectric vibrator side (connecting conductor plates) 10a, 10b: IC chip side conductor board (conductor board for integrated circuit elements / conductor board for connections) 11: Conductive material 11d,11e: Narrow part 23a, 23b: Pads for mounting the first and second electro-vibrators (wiring patterns) 24a~24c: Pads (wiring patterns) for mounting the 1st to 3rd ICs 24e~24g: Pads (wiring patterns) for mounting ICs 5th to 7th 24d, 24h: Pads (wiring patterns) for mounting the 4th and 8th ICs. 25a~25d: External connection terminals 26a, 26b: First and second joint wiring sections (wiring patterns) 26c, 26d: Third and fourth joint wiring sections (wiring patterns) 27a, 27b: First and second connection wiring sections (wiring patterns) 27c, 27d: Third and fourth connection wiring sections (wiring patterns) 31: Piezoelectric diaphragm (piezoelectric vibrating element) 32: First sealing member (sealing member) 33: Second sealing member (sealing member) C: Cut surface

Claims

1. A piezoelectric vibration device comprising an insulating substrate, a piezoelectric vibrator and an integrated circuit element mounted on one main surface of the insulating substrate, and a molded resin covering the piezoelectric vibrator and the integrated circuit element, 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, It comprises the other main surface on which external connection terminals are provided, A connecting conductor plate connected to the piezoelectric vibrator and / or the integrated circuit element is placed on one of the main surfaces of the insulating substrate at a position that does not overlap with the external connection terminal and is embedded in the molded resin. The side end surface of the connecting conductor plate is exposed to the outside from the boundary between the insulating substrate and the molded resin. A piezoelectric vibration device characterized by the following features.

2. The piezoelectric vibration device according to claim 1, characterized in that the connecting conductor plate comprises two piezoelectric vibrator-side conductor plates, each connected to the pair of excitation electrodes of the piezoelectric vibrator via a wiring pattern formed on one main surface of the insulating substrate.

3. The piezoelectric vibration device according to claim 1, characterized in that the connecting conductor plate comprises two integrated circuit element side conductor plates connected to the adjustment terminal and / or data writing terminal of the integrated circuit element via a wiring pattern formed on one main surface of the insulating substrate.

4. The piezoelectric vibration device according to claim 1, characterized in that the connecting conductor plate is made of metal with a thickness of 100 μm or more.

5. The piezoelectric vibration device according to claim 1, characterized in that the connecting conductor plate has a portion in the molded resin where a part of the connecting conductor plate in the width direction is a narrow region and / or a portion of the connecting conductor plate in the thickness direction is a thin-walled region.

6. On one main surface of the insulating substrate, at a position not overlapping with the external connection terminal, are provided two piezoelectric vibrator-side conductor plates, which serve as connecting conductor plates connected to a pair of excitation electrodes of the piezoelectric vibrator, and two integrated circuit element-side conductor plates, which serve as connecting conductor plates connected to the adjustment terminal and / or data writing terminal of the integrated circuit element. The piezoelectric vibration device according to claim 1, characterized in that the insulating substrate has a substantially rectangular shape, and the piezoelectric vibrator-side conductor plate and the integrated circuit element-side conductor plate are arranged symmetrically with respect to a line connecting the centers of a pair of long sides in the rectangle of the insulating substrate.

7. The process involves preparing to arrange multiple sets of piezoelectric vibrators, each comprising a piezoelectric vibrator having a pair of excitation electrodes and a sealing member for sealing the piezoelectric vibrator, and an integrated circuit element comprising an oscillation amplification circuit, in at least one row on one main surface of a single insulating substrate. The process involves connecting the piezoelectric vibrator and the integrated circuit element of a set to a wiring pattern including a plurality of pads provided on one main surface of the insulating substrate for each set, thereby connecting the integrated circuit element of the set to an external connection terminal provided on the other main surface of the insulating substrate for each set, and connecting the integrated circuit element of the set to the input and output sides of the pair of excitation electrodes of the piezoelectric vibrator of the set. The steps include: arranging a plurality of conductive plates, each having both ends electrically and mechanically joined, in a predetermined region of the insulating substrate between the piezoelectric vibrator of that set and the integrated circuit element of the set adjacent to the piezoelectric vibrator, at a position on one of the main surfaces that does not overlap with the external connection terminal, on the upper surface of the wiring pattern connected to the piezoelectric vibrator of that set and on the upper surface of the wiring pattern connected to the integrated circuit element of the set adjacent to the piezoelectric vibrator; With the piezoelectric vibrators and integrated circuit elements for each set connected to the wiring patterns of each set of the insulating substrate, the process of covering one main surface of the insulating substrate, each set of piezoelectric vibrators and integrated circuit elements, and the plurality of conductive members with a molding resin, The process involves cutting the insulating substrate and the molded resin at a cut surface that overlaps with the conductive member between the piezoelectric vibrator of the set and the integrated circuit element of the set adjacent to the piezoelectric vibrator, thereby separating the piezoelectric vibration device, which consists of the piezoelectric vibrator and the integrated circuit element mounted on the insulating substrate, into individual pieces for each set, and exposing the side end faces of the conductive member at both cut surfaces of the individualized piezoelectric vibration device. A method for manufacturing a piezoelectric vibration device, characterized by comprising the above.

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