JP2009264845A - Structure of gyro package and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gyro package which prevents contact between a stem body and a cap upon sealing a metal stem with the cap, and prevents occurrence of a spark and the like, and thereby does not influence components therein. <P>SOLUTION: The gyro package has a structure in which a metal stem 10 having a gyro component mounted thereon is sealed with a position determined metal cap 20. In the gyro package, the metal stem has a tapered stem body 11, and a flange part 22 of the metal cap and a flange part 12 of the metal stem are joined by electric welding. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a structure of a gyro package and a manufacturing method thereof, and more particularly to a structure and a method of hermetically sealing a cap of a gyro package by positioning the cap on a metal stem.

  A gyro that detects an angular velocity generated when a moving object rotates, for example, uses a piezoelectric element as a vibrator, is widely used as a navigation device for all moving objects such as automobiles, airplanes, and ships. In recent years, a more precise gyro for correcting the position of a moving body in units of 1 m has been demanded. Thus, in a gyro using a piezoelectric element, an electrode and a circuit portion for electrically extracting the piezoelectric element and its vibration are mounted on a metal stem and sealed with a cap to constitute a gyro package. Therefore, when manufacturing such a gyro package, the precision required for each component and the accuracy of work management in manufacturing are required in order to measure the delicate movement of the internal vibrator.

  Conventionally, a structure for positioning and sealingly bonding a metal cap of a gyro package to a metal stem has been as follows. That is, as shown in FIGS. 1 and 2, the metal stem 10 has a stem body portion 11 ′ and its flange 12 integrally formed, and the stem body portion 11 ′ is formed with respect to the upper surface of the flange 12. It has a structure that stands almost vertically. On the other hand, the cap 20 is integrally formed with a peripheral flange 22 and a cap main body 21 that rises substantially perpendicularly from the periphery of the flange and covers components such as electrodes and piezoelectric elements mounted on the upper surface of the stem body 11 ′. It is configured. Then, the cap 20 is positioned on the stem 10, and electric welding is performed between the flange 12 of the stem 10 and the flange 22 of the cap 20 to join the cap 20 to the stem 10. 1 and 2, illustration of components such as electrodes and piezoelectric elements mounted on the upper surface of the stem body 11 'is omitted.

  FIG. 3 shows a schematic appearance of a gyro package including a vibrator 13 made of a piezoelectric material, a ceramic 14 for supporting the vibrator 13 and the like. The vibrator 13 is mounted at the center of the rotation axis O inclined by a predetermined angle θ with respect to the vertical axis Z, and the angular velocity of the vibrator 13 with respect to the rotation axis O is detected.

  In the gyro package having such a structure, the positioning of the metal cap 20 on the metal stem 10 is determined by the dimensional accuracy of the product and the electrode guide. Further, the inner diameter dimensions of the body 11 ′ of the metal stem 10 and the cap 20 are designed so that they do not contact each other even when both of them swing to the maximum or minimum due to errors.

  As related prior art, there is Patent Document 1 (Japanese Patent Laid-Open No. 5-102332). In this document, in a semiconductor device such as a semiconductor laser, a metal stem and a cap are sealed by electric welding. It is an object of the present invention to obtain a highly accurate semiconductor device that does not cause a deviation of the center positions of the stem and the cap without using a complicated sealing device. According to this, by providing a tapered protrusion on the upper surface of the stem that is the same as or larger than the inner diameter of the cap, the cap is placed on the stem while being guided by the protrusion. And the stem are electrically welded. Therefore, variations in the center positions of the cap and the stem, and hence variations in laser output, are reduced.

Japanese Patent Laid-Open No. 5-102332

  An example of the conventional gyro package is shown in FIG. 1 and FIG. 2, but as an actual concrete aspect, a method of sealing the metal cap 20 with respect to the metal stem 10 and dimensions of the electrode guide Since the accuracy varies, basically, the contact between the cap 20 and the metal stem 10 is sealed only by the clearance between the stem body 11 of the metal stem 10 and the cap 20. There is a problem that cannot be prevented sufficiently. That is, no matter how much clearance is taken between the metal cap 20 and the metal stem 10, the guide property when guiding the electrode is poor, and as shown in FIG. When a misalignment occurs between the stem 10 and the metal cap 20, a contact occurs between the stem body 11 and the metal cap 20 at a position indicated by B in FIG.

  Also, when sealing the metal cap to the metal stem, if the stem body comes into contact with the inner diameter of the cap, the current will escape from the contact location or the voltage will be concentrated in one location. In some cases, welding may be poor at the location indicated by C in FIG. In addition, splashing or sparking may occur from contact points during electric welding, which may adversely affect the components mounted inside.

  In Patent Document 1, by providing a tapered protrusion on the top surface of the stem that is the same as or larger than the inner diameter of the cap, the cap is placed on the stem while being guided by the protrusion. Electrowel the cap and stem.

  However, Patent Document 1 is directed to a semiconductor laser device. A semiconductor chip is mounted on the stem, and a laser beam oscillated from the semiconductor chip (semiconductor laser) is placed on the cap. In order to position the center position of the cap with respect to the stem, the upper surface of the stem is provided with a tapered protrusion on the bottom that is the same as or larger than the inner diameter of the cap as described above. Then, the cap is placed on the stem while being guided by the protrusion, and the cap and the stem are electrically welded in this state.

  As described above, in Patent Document 1, since the cap must be accurately positioned at the center position with respect to the stem, the above-described structure is adopted. However, the positional relationship between the cap lens and the semiconductor chip is as follows. The mounting position of the semiconductor chip with respect to the stem, the mounting position of the lens with respect to the cap, the position of the tapered protrusion with respect to the stem, etc. must be precisely defined, and these errors are accumulated and the error in the position of the lens with respect to the semiconductor chip. Therefore, there is a problem in that accuracy management of each part and work management in manufacturing are complicated.

  Therefore, in the present invention, when the cap is sealed with a metal stem in the gyro package, the stem body and the cap are brought into contact with each other, causing splash, spark, etc., and affecting the internal components. We propose a structure of a gyro package that never happens.

  To achieve the above object, according to the present invention, in a vibration component mounting package having a structure in which a metal cap is positioned and sealed on a metal stem on which a vibration component is mounted, the stem barrel of the metal stem is provided. A structure of a package for mounting a vibration component is provided in which a portion is formed in a tapered shape and is joined by electric welding between a flange of a metal cap and a flange of a metal stem.

  According to the present invention, in the gyro package having a structure in which the metal cap is positioned and sealed on the metal stem on which the gyro component is mounted, the stem trunk portion of the metal stem is formed in a tapered shape, A gyro package structure is provided in which the flange of the cap and the flange of the metal stem are joined by electric welding.

  In these cases, a protrusion for electric welding is provided on at least one of the joint surfaces of the flange of the metal stem and the flange of the metal cap.

  According to the present invention, in the gyro package manufacturing method in which the metal cap is positioned and sealed on the metal stem on which the gyro component is mounted, the stem body of the metal stem is formed in a tapered shape, and the taper is formed. There is provided a method of manufacturing a gyro package characterized in that a metal cap is guided and positioned along a cylindrical stem body, and electric welding is performed between the flange of the metal cap and the flange of the metal stem. .

  In the present invention, since the stem trunk portion of the metal stem is formed in a taper shape, when the metal cap is joined to the metal stem, the inner peripheral wall of the metal cap becomes the tapered stem trunk portion of the metal stem. Even if a voltage is applied between the metal cap and the metal stem and an electric welding spark is generated at that time, the spark is blocked by the tapered stem body, The gyro parts accommodated therein are not affected, and electric welding can be appropriately performed at the joint surface between the flange of the metal stem and the flange of the metal cap.

  In this case, if an electric welding ridge is provided on at least one of the joint surfaces of the flange of the metal stem and the flange of the metal cap, the portion of the ridge is locally applied during the electric welding. The electric current is concentrated on the surface, and electric welding is performed along this protrusion.

  In addition, according to the gyro package manufacturing method of the present invention, since the stem trunk portion of the metal stem is formed in a tapered shape, an electric welding spark when the metal cap is joined to the metal stem is accommodated therein. The gyro parts are not affected, and a gyro package with good performance can be obtained.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  4 and 5 show the structure of the gyro package of the present invention. In the metal stem 10, the stem body 11 and the flange 12 thereof are integrally formed of, for example, an iron material by pressing or forging, and the surface thereof is plated with electrolytic or electroless nickel, or gold is electrolytically plated. It has been done. The stem body 11 has a structure in which the wall portion is inclined inwardly with respect to the upper surface of the surrounding flange 12. As described above, a gyro component (not shown) such as a vibrator made of a piezoelectric material and a ceramic that supports the vibrator is mounted on the upper surface of the stem body 11. Reference numeral 16 denotes an internal electrode connected to the internal gyro component, and reference numeral 17 denotes an external electrode extending to the outside of the stem 10.

  The metal cap 20 rises substantially vertically from the periphery of the peripheral flange 22 and the periphery of the flange, and the cap main body 21 covers the components (not shown) such as electrodes 16 and piezoelectric elements mounted on the upper surface of the stem body 11. Are integrally formed of an iron plate material by deep drawing of a press or the like, and the surface thereof is electrolessly plated with, for example, nickel or the like.

  The planar shape of the metallic stem 10 is rectangular or circular, and the metallic cap 20 also has a rectangular or circular shape corresponding to the shape of the metallic stem 10, and the inner diameter of the cap main body 21 of the metallic cap 20. These dimensions are slightly larger than the dimensions of the lower portion of the tapered stem body 11 of the metal stem 10. For example, the gap between the inner wall of the cap body 21 and the lower portion of the tapered stem body 11 is set to 0.5 μm or more. On the joint surface with the flange 22 of the metal cap 20, which is the upper surface of the flange 12 of the metal stem 10, a protrusion 15 at the time of electric welding of the flange 12 is formed. The ridge 5 is formed over the entire circumference of the flange 12.

  FIG. 6 shows a state in which the metal cap is guided and positioned on the metal stem, and electric welding is performed between the flange of the metal cap and the flange of the metal stem. The jig 30 that also serves as an upper electrode that holds the metal stem 10 has a guide groove 31 that guides and positions the periphery of the flange 12 of the metal stem 10, and the metal stem extends along the guide groove 31. Held in place. On the other hand, the metal cap 20 is held by a jig 40 that also serves as a lower electrode. When the metal cap 20 is sealed to the metal stem 10, the jigs 30 and 40 are moved up and down in a direction approaching each other, and the flange 22 of the metal cap 20 is moved to the flange 12 of the metal stem 10. Be joined. Simultaneously with the joining, a voltage is applied between the upper electrode 30 and the lower electrode 40, and electric welding is performed between them. At this time, current flows intensively on the ridge 15 provided on the flange 12 of the metal stem 10, and this portion melts locally, so that the sealing performance by electric welding between the flanges 12 and 22 is further improved. It will be solid.

  In the present invention, as described above, since the stem body portion 21 of the metal stem 10 is formed in a tapered shape, in the positioning when the electric welding is performed between the metal cap 20 and the metal stem 10, FIG. As shown by A, due to the accuracy of various parts, due to errors in work management, etc., or due to the difference in thermal expansion between the parts, the metal cap 20 is in relation to the metal stem 10. Even if there is a displacement in the horizontal direction from the normal position, the inner peripheral wall of the cap body 21 of the metal cap 20 is guided by the tapered stem body 11 of the metal stem 10 and along its slope. The metal cap 20 is corrected to a normal position in the horizontal direction with respect to the metal stem 10, and electric welding is performed at an appropriate position between the flange 11 of the metal stem 10 and the flange 21 of the metal cap 20.

  For example, when the flange 22 of the metal cap 20 contacts the tapered stem body 11 of the metal stem 10, a voltage is applied between the upper and lower electrodes 30, 40 to generate electric welding splash or spark. Even if it is assumed, since the electric spark generated at that time is blocked by the tapered stem body 11 and does not reach the inside of the gyro package, it affects the gyro parts (not shown) accommodated therein. Never give. In this way, the gyro package is hermetically sealed without causing poor welding between the flange 22 of the metal cap 20 and the flange 12 of the metal stem 10.

  Note that the inside of the gyro package hermetically sealed as described above is decompressed, and a rare inert gas such as nitrogen exists.

  Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above-described embodiments, and various forms, modifications, corrections, and the like are possible within the spirit and scope of the present invention. It is. For example, in the illustrated embodiment, the protrusion 15 for electric welding of the metal stem 10 is formed. Conversely, on the surface of the flange 22 of the metal cap 20 that is joined to the flange 12 of the metal stem 10, Alternatively, it is possible to form such ridges 15 on both sides of the metal stem 10 and the metal cap 20, or to form a plurality of such ridges 15 in any one of them.

  In the present invention, since the stem trunk portion of the metal stem is formed in a taper shape, when the metal cap is joined to the metal stem, the inner peripheral wall of the metal cap becomes the tapered stem trunk portion of the metal stem. It is guided and electric welding is performed at an appropriate position on the joint surface between the flange of the metal stem and the flange of the metal cap. Therefore, the present invention can be applied to a gyro package in a navigation device of any moving body such as an automobile, an aircraft, and a ship. The present invention is not limited to a gyro package, and can be applied to a package in which a metal cap is hermetically sealed with respect to a metal stem in any sensor or device having a vibrator inside.

FIG. 1 shows the structure of a conventional gyro package. FIG. 2 shows a conventional gyro package at the time of joining. FIG. 3 is a perspective view schematically showing the gyro package. FIG. 4 shows the structure of the gyro package according to the embodiment of the present invention. FIG. 5 shows a state in which the metal cap is joined to the metal stem in the gyro package of the present invention. FIG. 6 shows an outline of the configuration of an apparatus for joining a metal cap to a metal stem in the gyro package of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Metal stem 11 Stem trunk 12 Stem flange 15 Electric welding protrusion 20 Metal cap 21 Cap body 22 Cap flange 30, 40 Electrode 31 Guide groove

Claims (4)

  In a vibration component mounting package having a structure in which a metal cap is positioned and sealed on a metal stem on which the vibration component is mounted, the stem trunk portion of the metal stem is formed in a tapered shape, and the flange of the metal cap and the metal A structure of a vibration component mounting package characterized by being joined to a flange of a stem made by electric welding.   In a gyro package having a structure in which a metal cap is positioned and sealed on a metal stem on which a gyro component is mounted, the stem body of the metal stem is formed in a tapered shape, and the flange of the metal cap and the metal stem are A gyro package structure characterized by being joined to a flange by electric welding.   The structure of the package for mounting a vibration component according to claim 1 or 2, wherein a protrusion for electric welding is provided on at least one of the joint surfaces of the flange of the metal stem and the flange of the metal cap.   In a gyro package manufacturing method in which a metal cap is positioned and sealed on a metal stem on which a gyro component is mounted, the stem trunk portion of the metal stem is formed in a tapered shape, and the tapered stem barrel portion is formed along the tapered stem barrel portion. A method for producing a gyro package, characterized in that a metal cap is guided and positioned, and electric welding is performed between a flange of the metal cap and a flange of the metal stem.

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