JP2005241490A - Oscillator support structure and package for oscillator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily cope with the detection axes of various directions without changing the oscillation mode of the oscillator regarding the constitution for mounting an oscillator corresponding to prescribed detection axis on the mounting surface of a substrate for package. <P>SOLUTION: The support structure includes the substrate 31 for package; the support substrate 3 fixed on the mounting surface 31a of the substrate 31 for package; and the oscillator 1 corresponding to the prescribed detection axis Z. The supporting substrate 3 is extending to the direction C crossing with an angle θ to the mounting surface 31a. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a support structure for a vibrator such as a vibratory gyroscope and a vibrator package.

Patent Document 1 describes a multi-axis detection type vibration gyroscope capable of detecting rotational angular velocities in multi-axis directions. According to this document, three vibration gyro sensor modules are connected via a flexible substrate, then the flexible substrate is bent, and each sensor module is oriented in three different axial directions.
Japanese Patent Laid-Open No. 7-306047

  However, in the method described in Patent Document 1, it is necessary to attach a special connector or process the substrate on which the sensor module is mounted. In addition, it is difficult to perform a process for mounting the vibrator on the substrate.

  An object of the present invention is a structure for mounting a vibrator related to a predetermined detection axis on a mounting surface of a package substrate, and changing a vibration mode of the vibrator with respect to a detection axis in various directions. It is to be able to easily cope without doing.

The present invention includes a package substrate, a support substrate fixed to the mounting surface of the package substrate, and a vibrator supported on the support substrate and corresponding to a predetermined detection axis. Extends in a direction intersecting with the mounting surface, according to the vibrator support structure.
The present invention also relates to a vibrator package comprising the support structure and a lid combined with the package substrate.

With reference to FIGS. 1A to 1C, the function and effect of the present invention will be further described.
In the present invention, the vibrator 1 is fixed on the surface 3 a of the support substrate 3 by, for example, the bonding wire 2. The detection axis of the vibrator 1 is assumed to be Z. In the state of FIG. 1A, the plane of the vibrator 1 and the surface 3a of the support substrate 3 are substantially parallel, and the detection axis Z and the surface 3a are substantially perpendicular.

  The support substrate 3 is bent as shown in FIG. 1B to produce a support portion 3a for supporting the vibrator 1 and a fixing portion 3b for the package substrate. For example, 3a and 3b are made vertical. Next, the fixing portion 3b of the support substrate 3A is fixed on the mounting surface 31a of the package substrate 31 as shown in FIG. Thereby, the detection axis Z of the vibrator 1 can be made substantially parallel to the direction A of the mounting surface 31a. By changing the bending angle θ, various angles formed by the detection axis Z and the mounting surface 31a can be changed.

  Thus, according to the present invention, by changing the shape of the support substrate 3, the angle of the detection axis Z relative to the mounting surface 31a can be variously changed without changing the vibration mode (detection axis) of the vibrator 1. . Therefore, it is possible to orient the direction of the detection axis Z of the vibrator in the package in a desired direction while using the same type of package and using the same type of vibrator. Moreover, such a mounting process can be easily carried out by diverting a conventional mounting method by simply changing and adjusting the shape of the support substrate 3.

  In a preferred embodiment, the vibrator is held so as not to contact the support substrate. Thereby, when an impact is applied to the package, a change in the vibration state of the vibrator can be minimized, and damage to the vibrator can be prevented.

  In a preferred embodiment, the vibrator is supported on the support substrate by a bonding wire. In this case, the vibration state of the vibrator is hardly affected by the support. Particularly preferably, the bonding wire also serves as an electric wire for supplying power to the terminals of the vibrator.

  In a preferred embodiment, the support substrate is made by deformation of a flat plate, and includes a fixing portion that is bonded to the mounting surface of the package substrate. When positioning and supporting the vibrator on the flat plate, the positioning of the vibrator is relatively easy. Then, the step of forming the fixing portion by bending the support substrate after fixing the vibrator on the support substrate can be easily performed.

  In a preferred embodiment, the angle formed by the support substrate with respect to the mounting surface is 15 ° to 90 °, more preferably 30 ° or more. Particularly preferably, the support substrate is substantially perpendicular to the mounting surface.

  In a preferred embodiment, the detection axis Z of the vibrator is substantially parallel to the mounting surface 31 a of the package substrate 31. In another preferred embodiment, the vibrator extends planarly, and the plane B of the vibrator is substantially perpendicular to the mounting surface 31a. In a preferred embodiment, the vibrator extends in a plane, and the plane B of the vibrator is substantially parallel to the surface 3a of the support substrate 3A.

  The object to be measured by the vibrator of the present invention is, for example, a rotational speed and a rotational angular speed about a predetermined detection axis. In a preferred embodiment, the vibrator is a vibrator for a vibratory gyroscope.

  The material of the vibrator is not limited, but a piezoelectric single crystal is preferable. Crystal, lithium niobate single crystal, lithium tantalate single crystal, lithium niobate-lithium tantalate solid solution single crystal, lithium borate single crystal, langasite single crystal A piezoelectric single crystal made of, for example, is particularly preferable.

  The dimensions of the vibrator are not limited. However, if the weight and dimensions of the vibrator are large, gravity applied to the bonding wire increases, and the bonding wire may be deformed after a long period of time. For this reason, from the viewpoint of suppressing the influence on the vibration due to the deformation of the bonding wire, the width of the vibrator is preferably 10 mm or less, and more preferably 5 mm or less. From the same viewpoint, the weight of the vibrator is preferably 5 mg or less, and more preferably 1 mg or less. Further, the thickness of the vibrator is preferably 0.3 mm or less, more preferably 0.2 mm or less.

  The material of the support substrate is not particularly limited, and insulating materials used for so-called package applications such as ceramics, glass, and resin can be used.

The bonding method of the bonding wire to the vibrator is not limited, but ultrasonic bonding, spot welding, conductive adhesive, and soldering are preferable.
The material of the bonding wire is not particularly limited, but it needs to be a conductive material, and is preferably a material having flexibility or flexibility. From this viewpoint, copper with gold plating, nickel with gold plating, nickel, and aluminum are preferable.

The upper surface of the vibrator can be supported by the bonding wire. In this case, the vibrator is suspended downward from the end of the bonding wire. This form is suitable from the viewpoint of reducing the thickness of the entire support structure.
Alternatively, the lower surface of the vibrator can be supported by a bonding wire. This form is suitable from the viewpoint of stably supporting the vibrator for a long period of time.

Electronic components can be mounted on the package substrate. The type of electronic component is not particularly limited, but examples include a resistor, a capacitor, and a semiconductor integrated circuit chip. The type of chip is not particularly limited, but is preferably a semiconductor integrated circuit that processes the output signal of the angular velocity sensor. For example, an operational amplifier that constitutes a filter, an analog / digital converter that digitizes an analog output, Is preferably a serial communication driver that outputs the data to the outside via serial communication. When there is a terminal that can be directly connected to the vibrator from the outside of the angular velocity sensor, it is preferably a semiconductor integrated circuit chip that controls the drive signal and the detection signal of the vibrator.
Integrated Circuit: an application specific integrated circuit) is preferable.

The method for sealing the vibrator into the package is not limited, and examples thereof include the following methods.
(1) The sealing means is a semiconductor chip package. Examples of such packages include a QFP (Quad Flat Package) package and a QFN (Quad Flat No-lead) package.
(2) The sealing means is a resin mold material. Examples of the resin molding material include epoxy resin, silicone resin, polyimide resin, and urethane resin.
(3) The sealing means is a ceramic package. The cover is preferably seam welded or solder welded or gold soldered.
(4) The sealing means is a metal package. An example of the material is Kovar.
(5) The sealing means is a metal bent casing. Although it is not hermetically sealed, it is effective as an electromagnetic shield. Examples of the material include galvanized steel sheets and stainless steel.

A frame can be interposed on the support substrate, and the vibrator can be supported on the frame.
This frame may be made of an insulating material. In this case, each bonding wire can be directly fixed to the frame. Although the material of such a frame is not particularly limited, resin, insulating ceramics, and glass are preferable, and specifically, polyimide, quartz glass, and alumina ceramic are preferable. Moreover, the bonding method of the bonding wire to the frame includes, for example, adhesion, fitting, crimping, and caulking.

  This frame can be formed of a conductive material. Examples of this material include metals, conductive plastics, and metal plating resins. In particular, when the frame body is made of metal, the shape stability of the frame body is further increased, thereby further increasing the accuracy during alignment of the bonding wires. Examples of the metal include stainless steel, copper, nickel, aluminum, and brass.

  However, when the frame is formed of a conductive material, it is necessary to provide an insulator between the frame and each bonding wire to insulate the bonding wire from the frame. As such an insulator, polyimide resin, epoxy resin, and silicon resin are preferable. The form of the insulator is not particularly limited, but is preferably a film or sheet.

2 to 14 are views showing a support structure according to a preferred embodiment of the present invention.
FIG. 2 is a plan view showing the support substrate 4 used in this example. The support substrate 4 is provided with through holes 4a for bonding wires and a plurality of circular holes 4d.
FIG. 3 is a plan view showing the frame 7 used in this example. FIG. 4 is a plan view showing the bonding wire 9 used in this example. A pad 8 that is electrically connected to a terminal of the vibrator is formed at the tip of each bonding wire.

5 is a plan view showing a state in which the vibrator 11, the bonding wire 8, the support substrate 4 and the frame body 7 are laminated and integrated, and FIG. 6 is a sectional view taken along the line VI-VI of the assembly shown in FIG. FIG. 7 is a cross-sectional view of the assembly of FIG. 5 taken along the line VII-VII.
An insulating frame 7 is joined to the back side of the support substrate 4, and an end of the bonding wire 9 is joined to the surface of the frame 7. The bonding wire is bent and passes through the through hole 4 a, and the tip 8 of the bonding wire 9 is bonded to the terminal 21 of the vibrator 11.

  In this example, the vibrator 11 includes a central base portion 12, a pair of elongated support pieces 13 protruding from the base portion 12, a pair of drive vibration pieces 14 protruding from the tips of the support pieces 13, and the drive vibration pieces. A wide portion 15 provided at each tip is provided. Further, a pair of elongated detection vibrating pieces 16 protrude from the periphery of the base portion 12, and a wide portion 17 is provided at each tip of each detection vibrating piece 16. Each drive vibration piece 14 is provided with a drive electrode 18, and each detection vibration piece 16 is provided with a detection electrode 19. Each electrode 18, 19 is connected to a terminal 21 in the base 12.

  Next, the support substrate 4 of the assembly shown in FIGS. 5 to 7 is bent to obtain an assembly 33 of the form shown in FIGS. Here, as shown in FIG. 8, the end portion of the support substrate 4 is bent, and is divided into a fixing portion 4c to be fixed to the package substrate mounting surface and a support portion 4b on which the vibrator 11 is supported. ing. 9 is a plan view of FIG. 8 viewed from the arrow IX side (upper side), and FIG. 10 is a side view of FIG. 8 viewed from the arrow X side. In this example, the fixed portion 4c and the support portion 4b are bent substantially vertically, but the preferred range of this angle has been described above.

  Next, as shown in FIGS. 11A and 11B, the assembly 33 is placed and fixed on the package substrate 25 and covered with a lid 28 to obtain a package 29. In this example, the package substrate 25 includes a side wall 25b, and the electronic component 26 is accommodated in the accommodation hole 25a at the bottom. Further, the fixing portion 4 b is installed and fixed on the mounting surface 25 c of the substrate 25, whereby the vibrator 11 and its supporting portion 4 c stand in the package internal space 27. A lid 28 is placed on the upper surface of the side wall 25b and sealed.

  The package shown in FIG. 12 is the same as the package shown in FIG. However, the angle θ between the support portion 4c of the support substrate 4A and the mounting surface 25c is smaller than 90 °. FIG. 13 is a perspective view showing a state of the internal space 27 of the package of FIG.

  In the packages shown in FIGS. 12 and 13, when the angle θ formed by the support portion 4c with the mounting surface changes, the detection axis of the vibrator is displaced from the target direction, and the measurement error increases. Therefore, it is possible to suppress the deformation of the support portion 4c by installing the spacer 31 on the back surface side of the support portion 4c shown in FIG. 14 and contacting and supporting the support portion 4c.

(A) is a front view which shows an assembly typically, (b) is a front view which shows the assembly produced by bending the support substrate 3 of the assembly 1 of (a), (c) is 2B is a front view schematically showing a state in which the assembly of (b) is fixed on the package substrate 4. FIG. It is a top view which shows the support substrate 4 used by one Embodiment. It is a front view which shows the insulator 7 fixed on the support substrate 4. FIG. 3 is a plan view showing a form of a bonding wire 9. FIG. It is a top view which shows the assembly body before bending. It is sectional drawing which shows the assembly body before bending (figure seen from the arrow VI-VI direction in FIG. 5). It is sectional drawing which shows the assembly body before bending (The figure seen from the arrow VII-VII direction in FIG. 6). It is a front view which shows the assembly produced by bending the support substrate 4 of the assembly of FIGS. It is the top view which looked at the assembly of FIG. 8 from the arrow IX direction. It is the side view which looked at the assembly of Drawing 8 from the arrow X direction. (A) is a top view which shows the state which accommodated the assembly 33 of FIGS. 8-10 in the package 25, (b) is sectional drawing of the package of (a). It is sectional drawing which shows the state which accommodated the assembly in the package, and angle (theta) which the support part 4c makes with respect to the mounting surface 25c is smaller than 90 degrees. It is a perspective view which shows the inside of the package of FIG. It is sectional drawing which shows the state which accommodated the assembly in the package, The angle (theta) which the support part 4c makes with respect to the mounting surface 25c is smaller than 90 degrees, and the spacer 31 is installed in the back surface side of the support part 4c. .

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 11 Vibrator 2, 9 Bonding wire 3, 4 Support substrate 3a, 4a Support part 3b, 4c Fixed part 7 Insulator 26 Electronic component 29 Package 31 Package substrate 31a Mounting surface of package substrate 31 Assembly assembly A Mounting A plane parallel to the surface 4a B A plane parallel to the transducer 1 C A plane parallel to the support portion 3a Z Detection axis

Claims (10)

  A package substrate, a support substrate fixed to the mounting surface of the package substrate, and a vibrator supported on the support substrate and corresponding to a predetermined detection axis, the support substrate being mounted A support structure for a vibrator, characterized by extending in a direction intersecting the surface.   The support structure according to claim 1, wherein the vibrator is held so as not to contact the support substrate.   The support structure according to claim 1, wherein the vibrator is supported on the support substrate by a bonding wire.   The said support substrate is produced by the deformation | transformation of the flat plate, and is provided with the fixing | fixed part joined with respect to the said mounting surface, The claim as described in any one of Claims 1-3 characterized by the above-mentioned. Support structure.   The support structure according to any one of claims 1 to 4, wherein an angle formed by the support substrate with respect to the mounting surface is 15 ° to 90 °.   The support structure according to any one of claims 1 to 5, wherein the detection axis of the vibrator is substantially parallel to the mounting surface.   The support structure according to any one of claims 1 to 6, wherein the vibrator extends in a plane, and the plane of the vibrator is substantially perpendicular to the mounting surface. .   8. The vibrator according to claim 1, wherein the vibrator extends in a plane, and the plane of the vibrator is substantially parallel to the surface of the support substrate. Support structure.   The support structure according to any one of claims 1 to 8, wherein the vibrator is a vibrator for a vibratory gyroscope for detecting a rotational angular velocity.   A vibrator package comprising the support structure according to any one of claims 1 to 9 and a lid combined with the package substrate.

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