JP4847735B2 - Method for manufacturing piezoelectric device - Google Patents

Description

The present invention relates to a method for manufacturing a piezoelectric device such as a crystal resonator used in an electronic device such as a portable communication device or an electronic computer.

      Conventionally, piezoelectric components have been used to generate reference signals for electronic devices such as portable communication devices. As such a conventional piezoelectric component, a seal ring is attached on a base made of a ceramic material or the like, and a quartz crystal vibration element as a piezoelectric vibration element is provided on the upper surface of the base located inside the previous seal ring. There is known a structure in which a quartz vibrating element is hermetically sealed by mounting and fixing a metal lid on the seal ring and holding the metal lid on the seal ring (for example, Patent Documents) 1).

      In the piezoelectric device, a plurality of insulating bases 51 manufactured by batch processing are arranged vertically and horizontally on a tray-like transport jig with the cavities facing upward, and crystal resonator elements 52 are mounted on the individual insulating bases. Then, it is manufactured by the procedure of hermetically sealing with the lid 53. Two mounting electrodes are arranged on the inner bottom surface of the cavity of the insulating base 51, and the crystal resonator element 52 is mounted on the mounting electrode of the insulating base 51. As a method of hermetically sealing the insulating base 51 and the lid 53, there is a method of melting a gold tin (Au—Sn) brazing material as a bonding material. As melting means, there are known a method of heating in a vacuum atmosphere while being stored in a carbon jig, and a method of melting and bonding a bonding material with a halogen beam.

JP 2002-111435 A (Page 5-6, FIG. 2) Japanese Unexamined Patent Publication No. 2000-22013 (page 7, figure 3) Japanese Patent Laid-Open No. 9-246414

      In addition, the applicant did not find any prior art documents related to the present invention by the time of filing of the present application other than the prior art documents specified by the above prior art document information.

      However, in the above-described conventional piezoelectric device, the sealing material is hermetically sealed by melting the bonding material. However, the bonding material is wet because the gap between the lid and the insulating base is slightly spaced at the time of sealing. It has the disadvantages that sealing does not spread and the lid body may be displaced and bonded.

      Also, when assembling a piezoelectric device after preparing the individual insulating base and the individual lid in advance, it is necessary to hold the plurality of insulating bases individually on the carrier, and the carrier is held on the carrier. The lids had to be individually aligned and mounted on the individual insulating substrates, and this also had the disadvantage that the assembly process of the crystal resonator was complicated.

The present invention has been devised in view of the aforementioned drawbacks, and its object is adapted to stably bond the lid and the insulating substrate, a manufacturing how the piezoelectric device having improved significantly the productivity There is to do.

The method for manufacturing a piezoelectric device according to the present invention includes a step A of placing an insulating base provided with a sealing conductor pattern on a sealing device including a pedestal portion and a heating source, and a piezoelectric vibration element on the insulating base. And mounting the lid body on the sealing conductor pattern of the insulating base so that a sealing material provided on the lid body is in contact with the sealing conductor pattern ; and When the sealing material is melted by being irradiated with heat rays from a heating source part and joined to the sealing conductor pattern of the insulating base , the lid is removed by an electromagnet provided on the base part of the sealing device. A process of joining the sealing material and the sealing conductor pattern while applying vibration to the pedestal portion by attracting it to the pedestal portion side so as to be in close contact with the insulating base and repeating ON / OFF of the electromagnet. Characterized by comprising C Than is.

      According to the method for manufacturing a piezoelectric device of the present invention, the lid is bonded to the sealing conductor pattern of the insulating base, and the lid is brought into close contact with the insulating base at the time of bonding, thereby sealing to the sealing conductor pattern. It becomes possible to promote the wetting and spreading of the material.

      According to the method for manufacturing a piezoelectric device of the present invention, in step C, the bottom surface side or the lid side of the insulating base is fixed by magnetic force by using an electromagnet. It is possible to prevent the positional deviation at.

      Further, according to the method for manufacturing a piezoelectric device of the present invention, in step C, vibration is applied to the bottom surface side or the lid body side of the insulating base by using the vibration device. It is possible to promote the wetting and spreading of the sealing material to the conductive pattern for sealing by bringing the pattern into close contact.

      Further, according to the method for manufacturing a piezoelectric device of the present invention, by using a master substrate on which a plurality of insulating bases are formed, the master substrate itself functions as a carrier when the piezoelectric device is assembled. The complicated work of holding the individual pieces divided from the master substrate individually on the carrier or attaching the lid to each individual piece becomes unnecessary. As a result, the assembly process of the piezoelectric device is greatly simplified, and it is possible to improve the productivity of the piezoelectric device.

      In addition, according to the method for manufacturing a piezoelectric device of the present invention, the lid and the insulating substrate sealing conductor pattern are in close contact with the insulating base on the side of the insulating base that is not suitable for the heating means. Therefore, it becomes possible to promote the wetting and spreading of the sealing material to the sealing conductor pattern.

      Further, according to the method for manufacturing a piezoelectric device of the present invention, the bottom surface side or the lid body side of the insulating base is fixed by magnetic force by using the electromagnet that closely attaches the lid to the insulating base. It is possible to prevent the positional deviation at the time of joining.

      Further, according to the method for manufacturing a piezoelectric device of the present invention, since the vibrating device is used as means for bringing the lid into close contact with the insulating base, the sealing conductor pattern of the lid and insulating base is brought into close contact. It becomes possible to promote the wetting and spreading of the sealing material to the conductor pattern.

      Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic exploded perspective view of a crystal resonator viewed obliquely from above when the manufacturing method of the present invention is applied to the manufacture of a crystal resonator. The crystal resonator shown in FIG. 1 is generally composed of an insulating base 1, a crystal resonator element 2 as a piezoelectric resonator element, and a lid 3.

      The insulating substrate 1 is formed by laminating an insulating layer made of a ceramic material such as glass-ceramic or alumina ceramic, and surrounds a mounting area for the pair of mounting pads 6 and the crystal resonator element 2 on the upper surface thereof. A sealing conductor pattern 4 is provided, and an external terminal 5 such as an input terminal, an output terminal, and a ground terminal is provided on the lower surface.

      The pair of mounting pads 6 provided on the insulating base 1 are electrically connected to the vibrating electrodes of the crystal resonator element 2 on the upper surface side via a conductive adhesive, and the conductors on the insulating base 1 on the lower surface side. It is electrically connected to an input / output terminal (input terminal, output terminal) on the lower surface of the insulating substrate via a pattern, a via conductor inside the insulating substrate, or the like.

      The sealing conductor pattern 4 on the upper surface of the insulating base is formed by sequentially depositing a nickel (Ni) layer and a gold (Au) layer on the surface of a base layer made of, for example, tungsten (W), molybdenum (Mo) or the like. Thus, the inner peripheral portion extends to the inner wall surface of the recess 7 and the outer peripheral portion extends to the outer surface of the base body 1. The sealing conductor pattern 4 is for bonding a lid 3 to be described later to the upper surface of the insulating substrate 1 through a bonding material 8, and the sealing conductor pattern 4 is, as described above, By adopting a structure in which a Ni layer and an Au layer are sequentially deposited on the surface of a base layer made of W or Mo, the wettability of the bonding material 8 to the sealing conductor pattern 4 is improved, and the reliability and production of the piezoelectric device Property can be remarkably improved. The external terminal 5 described above is electrically connected to the circuit wiring of the external electric circuit via a conductive adhesive such as solder when the crystal resonator is mounted on an external electric circuit such as a mother board. .

      Further, the crystal resonator element 2 mounted on the upper surface of the insulating base 1 described above has a pair of vibration electrodes (not shown) on both main surfaces of a crystal piece having a thickness of approximately 30 μm to 160 μm cut along a predetermined crystal axis. ), And when a variable voltage from the outside is applied to the crystal piece via a pair of vibrating electrodes, thickness shear vibration is caused at a predetermined frequency. Such a quartz crystal resonator element 2 is electrically and mechanically connected via a conductive adhesive 9 to the vibrating electrodes attached to both main surfaces thereof and the corresponding mounting pads 6 on the upper surface of the insulating substrate. Is mounted at a predetermined position on the upper surface of the insulating substrate.

      The lid 3 is manufactured by adopting a conventionally known metal processing method and molding a metal such as 42 alloy into a predetermined shape. A nickel (Ni) layer is formed on the upper surface of the lid 3, and a clad gold-tin (Au—Sn) layer as the sealing material 8 is further formed on the upper surface of the nickel (Ni) layer. The The thickness of the clad gold-tin (Au—Sn) layer is 10 μm to 30 μm. For example, the component ratio is 80% gold and 20% tin.

Next, a manufacturing method of the above-described piezoelectric device will be described with reference to FIG. Here, FIGS. 3A to 3C are perspective views as seen from obliquely above for explaining the manufacturing method of the present invention.
(Process A)
As shown in FIG. 3A, the master substrate 10 is formed by laminating two layers of rectangular flat plates made of a ceramic material such as glass-ceramic and alumina ceramic, and in a matrix shape made of a ceramic material. Each substrate region is formed by laminating a plurality of substrates having a plurality of rectangular holes arranged in a matrix of m columns × n rows, and having the holes arranged in a matrix at the center. A pair of mounting pads 6 on the bottom surface of the recess and a sealing conductor pattern 4 surrounding the periphery of the opening are deposited and formed on the upper surface side, and external terminals 5 such as input / output terminals and ground terminals are deposited on the lower surface side.・ It is formed. In addition, a predetermined margin area is provided between the substrate areas arranged in a matrix. Such a master substrate 10 includes, for example, a mounting pad 6, an external terminal 5, and a sealing material on the surface of a ceramic green sheet obtained by adding and mixing a suitable organic solvent to a ceramic material powder made of alumina ceramic or the like. It is manufactured by printing and applying a conductor paste to be a conductor pattern 4 or the like in a predetermined pattern, laminating a plurality of these, press molding, and firing at a high temperature.

(Process B)
The master substrate 10 is formed by arranging a plurality of rectangular substrate regions adjacent to each other, and the crystal resonator element 2 is mounted on one main surface side thereof. The quartz resonator element 2 is formed by depositing and forming a pair of vibrating electrodes on both main surfaces of a quartz piece cut along a predetermined crystal axis, and an external fluctuation voltage is applied to the quartz piece via the pair of vibrating electrodes. Then, thickness shear vibration is caused at a predetermined frequency. Further, one crystal resonator element 2 is mounted on the bottom surface of the concave portion of each substrate region of the master substrate 10, and the vibration electrode of the crystal resonator element 2 and the mounting pad 6 on the upper surface of the master substrate are interposed via the conductive adhesive 9. Electrically and mechanically connected.

      Next, the lid 3 is sealed so that the crystal resonator element 2 is sealed in correspondence with the sealing conductor pattern 4 formed on the upper surface of the substrate region of the master substrate on which the crystal resonator element 2 is mounted. , Place and join. The lid 3 is manufactured by adopting a conventionally known metal processing method and molding a metal such as 42 alloy into a predetermined shape. A nickel (Ni) layer is formed on the upper surface of the lid 3, and a clad gold-tin (Au—Sn) layer as a sealing material is further formed on the upper surface of the nickel (Ni) layer. The thickness of the clad gold-tin (Au—Sn) layer is 10 μm to 30 μm. For example, the component ratio is 80% gold and 20% tin.

(Process C)
Here, although not shown, the sealing device is configured by a pedestal portion 11 for placing and fixing the master substrate 10 and an irradiation portion for irradiating a light beam such as a xenon lamp and a halogen lamp. ing. The lid 3 is irradiated on the lid 3 and the sealing material 8 is melted to seal the lid 3 to the substrate region of the master substrate 10. At this time, a plurality can be sealed simultaneously. A xenon lamp is a bulb in which a cathode and an anode are arranged inside. The xenon lamp condenses the position of the highest luminance of the light emitting part at the focal point of the condensing mirror and emits it to the focal point from the exit end of the optical fiber. is there. Similarly, the halogen lamp is provided with a tungsten filament in a bulb and sealed with a halogen gas. When this tungsten filament is energized and heated, it reacts with the halogen gas to produce a tungsten-halogen compound. Tungsten-halogen compounds generate a light beam by repeating a halogen cycle in which tungsten-halogen compounds are transported to the vicinity of the filament by convection in the bulb, decomposed into tungsten and halogen gas at a high temperature, and tungsten precipitates in the filament. To do. That is, in this process C, when the lid 3 is irradiated with the above-described light beam and the sealing material (bonding material 8) is melted and bonded to the sealing conductor pattern 4 of the insulating base 1, the pedestal 11 The sealing material (bonding material 8), which has started melting, is accelerated and shocked, and the melting is started and the lid 3 is bonded to the insulating base 1 in close contact.

      As shown in FIG. 4 (a), although not shown in FIG. 4 (a), an electromagnet is embedded in the pedestal 11 of the sealing device, and ON / OFF is performed based on the control signal. OFF-controlled. When the sealing material 8 reaches the melting point, the control signal is turned ON so that the lid 3 and the sealing conductor pattern 4 of the insulating base 1 are attracted by the magnetic force generated from the electromagnet and are brought into close contact with each other. be able to. At this time, the melting of the sealing material 8 that has started melting is accelerated by the vibration of the pedestal portion 11 that is generated by repeatedly turning on and off the control signal. As a result, the sealing material 8 It becomes possible to promote the wetting and spreading to the conductor pattern 4 for sealing. At this time, the lid 3 is attracted in the direction of the arrow shown in the figure and is brought into close contact therewith.

      Further, as shown in FIG. 4B, the bottom surface of the insulating base 1 is directed to the heat source side, the lid side is brought into contact with the pedestal portion 11 of the sealing device, and the electromagnet embedded in the pedestal portion 11 is controlled. It is also possible to perform hermetic sealing while performing ON / OFF control based on the signal. At this time, the insulating substrate 1 is attracted in the direction of the arrow shown in the figure and is brought into close contact therewith.

      Finally, as shown in FIG. 3C, the substrate is cut and divided along each substrate region of the master substrate 10 and the outer periphery of the substrate region. The master substrate 10 is cut by a dicing apparatus using a dicer or the like, and each piezoelectric device can be obtained by dividing the master substrate 10 into individual substrate regions through the cutting process.

      In addition, this invention is not limited to the above-mentioned embodiment, A various change, improvement, etc. are possible in the range which does not deviate from the summary of this invention. In the above-described embodiment, the crystal resonator is configured by using a crystal resonator element as an electronic component element. However, other electronic devices, for example, an IC element or another piezoelectric element is used as the electronic component element. The present invention can also be applied to such an electronic device, and it goes without saying that these are also included in the technical scope of the present invention.

      Further, FIG. 5 shows a state in which the master substrate 10 is brought into contact with the pedestal portion 11 of the sealing device.

      Further, in the above-described embodiment of the present invention, the halogen lamp and the xenon lamp are shown as the heat source of the sealing device. However, it may be sealed using another heating source such as a carbon jig. Needless to say, such a case is included in the technical scope of the present invention.

      In the above-described embodiment of the present invention, a heating device may be provided on the base 11 of the sealing device, and the insulating base 1 may be preheated. By performing the preheating, there is no sudden temperature change in the insulating base 1, so that the effect of preventing cracking of the insulating base 1 due to thermal stress is achieved.

It is the outline exploded perspective view which looked at the crystal oscillator (piezoelectric device) manufactured with the manufacturing method of the present invention from the slanting upper part. 1 is a schematic side cross-sectional view of a crystal resonator (piezoelectric device) manufactured by a manufacturing method of the present invention as viewed from the side. BRIEF DESCRIPTION OF THE DRAWINGS (a) thru | or (c) are the outline external perspective views seen from diagonally upward for demonstrating the manufacturing method concerning one Embodiment of this invention. (A) And (b) is the schematic sectional side view seen from the side direction, respectively for demonstrating the manufacturing method of the piezoelectric device concerning one Embodiment of this invention. It is the schematic perspective view seen from diagonally upward for demonstrating the manufacturing method at the time of using the master board | substrate concerning one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Insulation base | substrate 2 ... Crystal oscillation element (piezoelectric oscillation element)
DESCRIPTION OF SYMBOLS 3 ... Cover body 4 ... Conductive pattern for sealing 5 ... External terminal 6 ... Mounting pad 7 ... Recessed part 8 ... Sealing material 9 ... Conductive adhesive material 10 ... Master board 11 ... Pedestal part

Claims (1)

Placing the insulating substrate provided with the sealing conductor pattern on a sealing device comprising a pedestal part and a heating source part; and
A step of mounting the piezoelectric vibration element on the insulating base and disposing the lid on the sealing conductor pattern of the insulating base so that the sealing material provided on the lid is in contact with the sealing conductor pattern B and
Said been irradiated heat rays from the heating source portion is melted the sealant to the lid member, when joined to the sealing conductor pattern of the insulating substrate, by an electromagnet provided in the base portion of the sealing device The sealing member and the sealing conductor pattern are applied while the lid is attracted to the pedestal portion side to be brought into close contact with the insulating base and vibration is applied to the pedestal portion by repeating ON / OFF of the electromagnet. step C of bonding the bets
A method for manufacturing a piezoelectric device comprising:

Images