JP2010245933A - Piezoelectric resonance component and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric resonance component capable of improving the fixing strength of a metal cap and to provide a method for manufacturing the piezoelectric resonance component. <P>SOLUTION: The piezoelectric resonance component includes: a substrate 11 which forms terminal electrodes 16a at least on an upper surface and is composed of an insulating material; a piezoelectric element 13 mounted on the upper surface of the substrate 11; and a metal cap 15 fixed on the upper surface of the substrate 11 through seal resin 14 so as to seal off the piezoelectric element 13. The metal cap 15 is formed by half-etching a metal plate and has a bottom face of the same plane, so that the metal cap 15 and the capacity substrate 11 are mutually connected through the seal resin 14 on the whole bottom face of the metal cap. Consequently an adhesive area between the metal cap 15 and the seal resin 14 is increased and the fixing strength of the metal cap 15 can be improved. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a piezoelectric resonant component including a piezoelectric resonant element on a capacitive substrate represented by, for example, a piezoelectric oscillator.

  In recent years, with the downsizing, low profile, high accuracy, and low price of electronic devices, the demand for smaller and more accurate piezoelectric oscillators used in electronic devices has increased. Instead, surface mount type piezoelectric resonant components are widely used. A piezoelectric oscillator is known as an example of a surface-mount type piezoelectric resonant component. The piezoelectric resonator includes a capacitive substrate having a rectangular internal electrode layer, a piezoelectric resonant element mounted on the capacitive substrate via a conductive adhesive, and sealed on the capacitive substrate so as to seal the piezoelectric resonant element. An alumina cap fixed through a stop resin is provided as a package. As described above, a ceramic cap such as alumina or a resin cap is generally used as a package of a surface mount type piezoelectric resonant component. In some cases, it was bulky and could not satisfy the demands for small size and low profile. Therefore, in order to reduce the product height, a package that uses a metal cap has been proposed.

  And, for example, in Patent Document 1, after drawing a thin metal plate so that a flange is formed on the outer periphery of the opening of the metal cap, the flange is positioned near the outer surface of the cap and the outer surface. A piezoelectric component is disclosed in which an opening of a metal cap is bonded and sealed in a substantially line contact state with a substrate by cutting in parallel.

JP-A-8-111627

  However, when the metal cap and the upper surface of the capacitor substrate are connected via the sealing resin, there is a problem that the bonding strength between the metal cap and the sealing resin is small, so that the fixing strength of the metal cap is weak.

  The present invention solves the above-described problems, and an object of the present invention is to provide a piezoelectric resonant component and a method for manufacturing the piezoelectric resonant component that improve the fixing strength of a metal cap.

  In order to achieve the above object, a piezoelectric resonant component of the present invention seals a substrate made of an insulating material having terminal electrodes formed on at least an upper surface, a piezoelectric element mounted on the upper surface of the substrate, and the piezoelectric element. And a metal cap fixed to the upper surface of the substrate through a sealing resin. The metal cap is formed by half-etching a metal plate and has a bottom surface on the same plane.

  The method for manufacturing a piezoelectric resonant component according to the present invention includes a step of mounting a piezoelectric element on a substrate made of an insulating material having a terminal electrode formed on at least the upper surface, and sealing the piezoelectric element on the upper surface of the substrate. And a step of fixing the metal cap via a stop resin, wherein the metal cap is formed by half-etching a metal plate.

  According to the piezoelectric resonant component of the present invention, since the metal cap and the capacitor substrate are connected via the sealing resin on the entire bottom surface of the metal cap, the bonding area between the metal cap and the sealing resin increases, Fixing strength can be improved.

  In addition, according to the method for manufacturing a piezoelectric resonant component of the present invention, the metal cap is manufactured by half-etching the metal plate. Therefore, the metal cap having the same bottom surface can be easily manufactured. Moreover, the metal cap whose surface roughness of the inner surface of the metal cap is rougher than the surface roughness of the bottom surface of the metal cap can be easily manufactured. Therefore, the metal cap and the capacitor substrate are connected through the sealing resin on the entire bottom surface of the metal cap, and the wettability of the sealing resin to the inner surface of the metal cap when the sealing resin is applied to the metal cap is improved. Therefore, the bonding area between the metal cap and the sealing resin is increased, and a piezoelectric resonant component having a strong fixing strength of the metal cap can be obtained.

1 is an exploded perspective view of a piezoelectric resonator according to a first embodiment of the present invention. Sectional drawing of the AA surface of the piezoelectric oscillator in Embodiment 1 of this invention Sectional drawing of the BB surface of the piezoelectric oscillator in Embodiment 1 of this invention The bottom view of the metal cap in Embodiment 1 of this invention Sectional drawing of the piezoelectric oscillator in Embodiment 2 of this invention Cross-sectional view of a piezoelectric resonator in a comparative example Sectional drawing for demonstrating the manufacturing method of the metal cap in Embodiment 2 of this invention

(Embodiment 1)
Hereinafter, a piezoelectric resonator component and a method for manufacturing the same according to the first embodiment will be described with reference to the drawings by taking a piezoelectric resonator as one of the piezoelectric resonator components as an example.

  FIG. 1 is an exploded perspective view of the piezoelectric oscillator according to the first embodiment of the present invention, and FIG. 2 is a cross-sectional view of the AA plane of the piezoelectric oscillator according to the first embodiment of the present invention.

  As shown in FIGS. 1 and 2, the piezoelectric resonator according to the first embodiment of the present invention includes a piezoelectric resonance element 13 having a vibration confinement electrode 18 mounted on a capacitor substrate 11 via a conductive adhesive 12. And a metal cap 15 fixed on the capacitor substrate 11 via a sealing resin 14 so as to seal the piezoelectric resonant element 13. The metal cap 15 has a coplanar metal cap bottom surface 15a and a metal cap inner side surface 15b formed by half-etching from a metal plate. The surface roughness of the metal cap inner side surface 15b is equal to that of the metal cap bottom surface 15a. It is rougher than the surface roughness. The metal cap bottom surface 15a, a part of the inner surface 15b of the metal cap, and a part of the outer surface 15c of the metal cap are bonded to the sealing resin 14.

  As described above, the piezoelectric resonator according to the present invention has the metal cap bottom surface 15a on the same plane, and the metal cap 15 and the capacitor substrate 11 are connected to each other through the sealing resin 14 over the entire metal cap bottom surface 15a. Therefore, the adhesion area between the metal cap 15 and the sealing resin 14 is increased, and the fixing strength of the metal cap 15 can be improved.

  Further, by making the surface roughness of the inner surface 15b of the metal cap rougher than the surface roughness of the bottom surface 15a of the metal cap, the sealing resin 14 on the inner surface 15b of the metal cap when the sealing resin 14 is applied to the metal cap 15 is obtained. Therefore, the adhesion area between the inner surface 15b of the metal cap and the sealing resin 14 is increased, and the fixing strength of the metal cap 15 can be further improved.

  Here, the reason why the surface roughness of the metal cap inner side surface 15b is made rougher than the surface roughness of the metal cap bottom surface 15a is that the surface roughness of the metal cap bottom surface 15a is reduced and the surface of the metal cap inner side surface 15b is made. This is because by increasing the roughness, it is possible to maintain the insulation between the metal cap 15 and the terminal electrode 16a on the upper surface of the substrate, and to improve the fixing strength of the metal cap 15.

  In addition, since the metal cap 15 has the bottom surface 15a in the same plane, a pressing force when a load is applied to the metal cap 15 is received by the plane, so that the pressing force does not concentrate on the local area and the metal cap shown in FIG. Since the distance between the bottom surface 15a and the terminal electrode 16a on the upper surface of the substrate can be maintained, insulation between the metal cap bottom surface 15a and the terminal electrode 16a on the upper surface of the substrate can be ensured.

  Furthermore, by using stainless steel as the material of the metal cap, corrosion of the metal cap can be suppressed and a strong piezoelectric oscillator can be obtained.

  Next, a method for manufacturing the piezoelectric resonator according to the first embodiment of the present invention will be described.

  First, a method for manufacturing the capacitor substrate 11 will be described with reference to FIGS.

First, an organic binder, a plasticizer, an organic solvent and, if necessary, a dispersing agent are mixed with a dielectric powder mainly composed of CaTiO ₃ to prepare a ceramic slurry, and this ceramic slurry is formed into a sheet by a doctor blade method or the like. Mold to obtain a green sheet. Next, a Pd paste is screen-printed on the green sheet to form a conductor layer pattern that becomes the internal electrode 17. Further, a Pd paste is screen-printed on another green sheet to form a conductor layer pattern that becomes the terminal electrode 16c on the lower surface of the substrate. Then, after laminating a plurality of these green sheets, a conductor layer pattern to be the terminal electrode 16a on the upper surface of the substrate is formed by transfer to obtain a laminate. And this laminated body is cut | disconnected and the laminated body of an individual piece is obtained.

  Next, in order to remove the plasticizer and the organic binder, the individual laminate is fired at a temperature of 1200 to 1400 ° C. for about 2 hours to obtain a sintered body.

  Next, Ag paste is applied to a predetermined position on the side surface where the internal electrode is exposed, dried, and then baked at a temperature of 700 to 900 ° C. to form the terminal electrode 16b on the side surface of the substrate. Next, Ni plating and Au plating are performed on the surface of the terminal electrode 16 to obtain the capacitor substrate 11 shown in FIG. The dimensions of the capacitive substrate 11 obtained as described above were 3.2 mm in length, 1.3 mm in width, and 0.3 mm in thickness. Further, the surface roughness Ra of the terminal electrode 16a on the upper surface of the substrate after Au plating was 1.0 μm. The surface roughness was measured using a contact type surface roughness meter.

  Next, a method for manufacturing the piezoelectric resonance element 13 will be described with reference to FIGS.

First, an Ag paste is applied to the front and back surfaces of a thick plate-like sintered body block made of a piezoelectric ceramic material containing PbTiZrO ₃ as a main component, dried, and then baked at 750 ° C. to form a polarization electrode. The sintered body block on which the electrode for polarization is formed is polarized by applying a DC voltage in the thickness direction of the sintered body block.

  Next, this sintered body block is cut with a dicing saw to form a rectangular thin plate. Then, the thickness direction of the rectangular thin plate is precisely polished so that a predetermined resonance frequency as a piezoelectric resonance element is obtained. Thereafter, the vibration confinement electrode 18 is formed by sputtering in the order of Cr, Cu, and Ag on the front surface, the back surface, and one end surface of the rectangular thin plate. Thereafter, a rectangular thin plate on which the vibration confinement electrode 18 is formed is cut out by a dicing saw so that the width dimension is 0.38 mm, and the piezoelectric resonant element 13 having a length of 2.0 mm, a width of 0.38 mm, and a thickness of about 160 μm is obtained. obtain.

  Then, the manufacturing method of the metal cap 15 is demonstrated using FIG. 2, FIG.

  First, a metal plate having an outer shape of 100 mm × 100 mm and a thickness of 0.4 mm is prepared using SUS304, which is a type of stainless steel. Next, the metal plate is later cut in the vertical direction and the horizontal direction to perform masking and half-etching so that a large number of metal caps can be obtained. Here, half etching refers to etching that is performed from one side and does not penetrate through the other side. A method of masking the metal plate and performing half etching will be described in detail below.

  First, a portion of the metal plate that becomes the metal cap bottom surface 15a is masked using a resist to prevent corrosion by the etching solution. The other surface is masked over the entire surface using a resist. Next, half etching is performed by applying an etching solution to the masked metal plate. A ferric chloride solution was used as an etching solution when performing half-etching. In this half etching, it is preferable that the thickness C of the central portion of the metal cap upper surface 15d is 5 to 50% of the thickness of the metal plate.

  Next, the half-etched metal plate is cut into individual pieces so as to have a predetermined size using a processing machine such as a laser processing machine or a dicing saw to obtain the metal cap 15 of the first embodiment. Here, the outer dimension of the obtained metal cap 15 is 3.0 mm × 1.0 mm × 0.4 mm. The vertical width D of the metal cap bottom surface 15a was 0.2 mm, the horizontal width E was 0.1 mm, and the thickness C of the central portion of the metal cap upper surface 15d was 0.1 mm. Further, the surface roughness Ra of the inner side surface 15b of the metal cap is 10 μm, the surface roughness Ra of the metal cap bottom surface 15a is about 0.1 μm, and the surface roughness Ra of the inner side surface 15b of the metal cap is set to that of the metal cap bottom surface 15a. It was made rougher than the surface roughness Ra.

  Next, a method for manufacturing a piezoelectric resonator using the capacitor substrate 11, the piezoelectric resonator 13, the metal cap 15, the conductive adhesive 12, and the sealing resin 14 obtained above will be described with reference to FIGS. 1 and 2. explain.

  First, the conductive adhesive 12 is formed on the terminal electrode 16a on the upper surface of the capacitor substrate 11 by screen printing. Thereafter, the piezoelectric resonant element 13 having the vibration confinement electrode 18 is mounted and pressed and fixed, and then the conductive adhesive 12 is cured at a temperature of 70 to 250 ° C., and the piezoelectric resonant element 13 is mounted and fixed on the capacitor substrate 11. At the same time, the vibration confinement electrode 18 of the piezoelectric resonance element 13 is electrically connected to the terminal electrode 16a on the upper surface of the substrate.

Next, a metal cap 15 shown in FIG. 1 is prepared, and a paste-like sealing resin 14 is applied to the metal cap bottom surface 15a, a part of the metal cap inner side surface 15b, and a part of the metal cap outer side surface 15c. After coating, the metal cap 15 is mounted on the capacitor substrate 11. As the sealing resin 14, an epoxy resin containing an insulating filler is used, and an insulating filler using SiO ₂ powder is used. The insulating filler content is 70 wt%, and the average particle diameter of the insulating filler. Was 5 μm and spherical. Here, the average particle diameter was measured based on an electron microscope image of a cross section of the cured sealing resin.

  Next, the sealing resin 14 is cured at a temperature of 185 ° C. while applying a load of about 100 gf to the metal cap 15, and the capacitor substrate 11 and the metal cap 15 are connected to obtain the piezoelectric oscillator of the first embodiment. .

  On the other hand, the structure and manufacturing method of the piezoelectric resonator of the comparative example were as follows.

  The piezoelectric resonator according to the comparative example is different from the piezoelectric resonator according to the first embodiment in the shape of the metal cap 35 and the connection between the metal cap 35 and the capacitor substrate 11 via the sealing resin 14. It is the same as that of the piezoelectric oscillator of the form 1.

  That is, in the piezoelectric resonator of the comparative example, as shown in FIG. 6, the shape of the opening of the metal cap 35 is a shape in which the flange portion is cut without having a bottom surface on the same plane. The opening of the cap 35 and the capacitor substrate 11 are connected.

  The piezoelectric oscillator manufacturing method of the comparative example includes the manufacturing method of the metal cap 35 and the connecting method of the metal cap 35 and the capacitor substrate 11 via the sealing resin 14. Other than this manufacturing method, the other processes are the same as the manufacturing method of the piezoelectric resonator according to the first embodiment.

  Details of the method for manufacturing the piezoelectric resonator of the comparative example will be described below.

  As shown in FIG. 6, after drawing a 0.1 mm thin metal plate so that a flange is formed on the outer periphery of the opening of the metal cap 35, the flange is positioned near the outer surface of the metal cap and The metal cap 35 is produced by cutting parallel to the outer surface. Then, the sealing resin 14 is applied to the opening of the metal cap 35, and the metal cap 35 is mounted on the capacitor substrate 11. Next, as in the first embodiment, the sealing resin 14 is cured at a temperature of 185 ° C. while applying a load of about 100 gf to the metal cap 35, and the capacitor substrate 11 and the metal cap 35 are connected to each other. The piezoelectric oscillator of is obtained. Here, the outer dimensions of the metal cap 35 are the same as those of the metal cap 15 of the first embodiment.

  And about the piezoelectric oscillator of this Embodiment 1 and a comparative example, the fixing strength of a metal cap was measured 30 each for each sample, and the average value was calculated | required and evaluated. The fixing strength was measured by pressing the metal cap from the direction G shown in FIG. The evaluation results are shown in (Table 1).

  As is apparent from the results of (Table 1), in the piezoelectric resonator of the first embodiment, the fixing strength of the metal cap is larger than that of the comparative example.

  As described above, in the method for manufacturing a piezoelectric resonator according to the present invention, a metal cap is manufactured by half-etching a metal plate. Therefore, a metal cap having a bottom surface on the same plane can be easily manufactured. Moreover, the metal cap whose surface roughness of the inner surface of the metal cap is rougher than the surface roughness of the bottom surface of the metal cap can be easily manufactured. Therefore, the metal cap and the capacitor substrate are connected through the sealing resin on the entire bottom surface of the metal cap, and the wettability of the sealing resin to the inner surface of the metal cap when the sealing resin is applied to the metal cap is improved. Therefore, the bonding area between the metal cap and the sealing resin is increased, and a piezoelectric oscillator having a strong fixing strength of the metal cap can be obtained.

  Further, since the metal cap is produced by half-etching the metal plate, the dimensional accuracy is good and it is advantageous for miniaturization.

  As shown in FIG. 4, in the first embodiment, the vertical width D at the bottom surface of the metal cap is 0.2 mm and the lateral width E is 0.1 mm. The width D and the width E in the horizontal direction are 0.05 mm or more, and a large fixing strength can be obtained as compared with the comparative example.

  Further, as shown in FIG. 2, since the thickness of the upper surface 15d of the metal cap is configured so as to increase from the vicinity of the center toward the peripheral portion, the compressive strength of the piezoelectric oscillator itself is also increased. When the strength at which the metal cap is deformed by pressing from the upper surface of the metal cap using a push-pull gauge was measured, the piezoelectric oscillator of the comparative example started to deform from 4 kgf, whereas the piezoelectric oscillator of the first embodiment was The deformation started from 3 times 12kgf. For this reason, the piezoelectric oscillator of the first embodiment has higher compressive strength than the piezoelectric oscillator of the comparative example. The deformation of the metal cap is not preferable because it causes a decrease in oscillation performance due to contact of the metal cap with the piezoelectric resonator element or peeling of the piezoelectric resonator element. It is also effective in that such problems can be suppressed.

  Moreover, as shown in FIG. 4, it produced so that the thickness F of the corner part of the metal cap bottom face 15a might become thicker than the width D of the vertical direction, and the width E of the horizontal direction. Thereby, the adhesion strength of the metal cap can be further improved.

(Embodiment 2)
Hereinafter, a piezoelectric resonant component and a method for manufacturing the same according to the second embodiment will be described with reference to the drawings by taking a piezoelectric resonator as one of the piezoelectric resonant components as an example. FIG. 5 is a cross-sectional view of the piezoelectric resonator according to the second embodiment of the present invention.

  The piezoelectric resonator according to the second embodiment of the present invention is different from the piezoelectric resonator according to the first embodiment in the shape of the metal cap 25 and the connection between the metal cap 25 and the capacitor substrate 11 via the sealing resin 14. Other than that, the piezoelectric resonator is the same as that of the first embodiment.

  That is, as shown in FIG. 5, the piezoelectric resonator according to the second embodiment has a metal cap outer surface 25e formed by half-etching the metal cap 25, and the surface roughness of the outer surface 25e of the metal cap. Is rougher than the surface roughness of the metal cap bottom surface 25a. The metal cap bottom surface 25a and a part of the inner surface 25b of the metal cap and a part of the metal cap outer surface 25e and the metal cap outer surface 25c formed by half etching are bonded to the sealing resin 14, The metal cap 25 and the capacitor substrate 11 are connected via the sealing resin 14.

  As described above, the piezoelectric resonator according to the present invention has at least a part of the surface roughness to which the sealing resin 14 on the outer surface of the metal cap 25 adheres to be rougher than the surface roughness of the metal cap bottom surface 25a. When the sealing resin 14 is applied to the metal cap 25, the wettability of the sealing resin 14 to the metal cap outer surface 15e formed by etching is improved. Therefore, the metal cap outer surface 15e and the sealing resin are improved. The adhesion area with 14 is increased, and the fixing strength of the metal cap 15 can be further improved.

  Here, the reason that the surface roughness of the metal cap outer surface 25e formed by half-etching is rougher than the surface roughness of the metal cap bottom surface 25a is to reduce the surface roughness of the metal cap bottom surface 25a, and Further, by roughening the surface roughness of the metal cap outer surface 25e formed by half-etching, the insulation between the metal cap 25 and the terminal electrode 16a on the upper surface of the substrate is maintained, and the metal cap 25 is fixed. This is because the strength can be improved.

  Next, a method for manufacturing the piezoelectric resonator according to the second embodiment of the present invention will be described.

  The manufacturing method of the piezoelectric resonator according to the second embodiment of the present invention includes a manufacturing method of the metal cap 25 and a method of connecting the metal cap 25 and the capacitor substrate 11 via the sealing resin 14 according to the first embodiment. Unlike the method for manufacturing the piezoelectric oscillator, the other processes are the same as those of the method for manufacturing the piezoelectric oscillator of the first embodiment.

  Details of the method of manufacturing the piezoelectric resonator according to the second embodiment will be described below.

  First, the manufacturing method of a metal cap is demonstrated below using FIG. 5, FIG.

  A metal plate having an outer shape of 100 mm × 100 mm and a thickness of 0.4 mm is prepared from SUS304, which is a type of stainless steel. Next, the metal plate is later cut in the vertical direction and the horizontal direction to perform masking and half-etching so that a large number of metal caps can be obtained. A method of masking the metal plate and performing half etching will be described in detail below.

  First, in order to produce the groove 20 used when the metal plate is cut into individual pieces, masking is performed using a resist on portions that do not become the groove 20 on the front surface and the back surface to prevent corrosion by the etching solution. Next, half etching is performed on the masked metal plate by applying an etching solution, and grooves 20 used when the metal plate is cut into individual pieces are formed on the front and back surfaces of the metal plate. Here, the width of the manufactured groove 20 was 100 μm, the width of the cutting margin was 50 μm, and the width of the groove 20 was larger than the width of the cutting margin 21. Thereafter, the resist on the front surface and the back surface is removed. Next, half-etching is performed on one surface of the metal plate in the same manner as in the first embodiment to produce a half-etched metal plate 19 as shown in FIG. Note that the same etchant as that in Embodiment 1 was used for half etching. Next, in order to divide the half-etched metal plate 19 into pieces of metal caps of a predetermined size, the width of the groove 20 formed on the front and back surfaces using a processing machine such as a laser processing machine or a dicing saw. The metal cap 25 of Embodiment 2 shown in FIG. The outer dimensions of the obtained metal cap 25 are 3.0 mm × 1.0 mm × 0.4 mm, the vertical width on the bottom surface of the metal cap is 0.175 mm, and the horizontal width is 0.075 mm. It was.

  Further, as shown in FIG. 7, when the half-etched metal plate 19 is cut into individual pieces, the portion of the groove 20 formed in advance is cut with a width of the cutting allowance 21 narrower than the groove 20. A region having a rough surface can be formed on the outer surface of the cap by half etching.

  Further, the surface roughness Ra of the outer surface 25e of the metal cap formed by half-etching with the inner surface 25b of the metal cap is 10 μm, and the surface roughness Ra of the metal cap bottom surface 25a is about 0.1 μm. The surface roughness of the side surface 25b and the surface roughness of the outer surface 25e of the metal cap formed by half-etching were made rougher than the surface roughness of the metal cap bottom surface 25a.

  Next, a method for connecting the metal cap and the capacitor substrate via the sealing resin will be described. The paste-like sealing resin 14 is applied to the outer surface 25e of the metal cap and a part of the outer surface 25c of the metal cap formed by half-etching the metal cap bottom surface 25a and the metal cap inner surface 25b of the metal cap 25. After coating, the metal cap 25 is mounted on the capacitor substrate 11. Here, the same sealing resin 14 as in the first embodiment was used.

  Next, the sealing resin 14 is cured at a temperature of 185 ° C. while applying a load of about 100 gf to the metal cap 25, and the capacitor substrate 11 and the metal cap 25 are connected to obtain the piezoelectric oscillator in the second embodiment. .

  And about the piezoelectric oscillator of this Embodiment 2, the fixing strength of a metal cap was measured 30 each for each sample similarly to this Embodiment 1, and the average value was calculated | required and evaluated. The evaluation results are shown in (Table 2).

  As is clear from the results of (Table 2), in the piezoelectric resonator of the second embodiment, the fixing strength of the metal cap is larger than that of the piezoelectric resonator of the first embodiment.

  As described above, in the method for manufacturing a piezoelectric resonator according to the present invention, the sealing resin on the outer surface of the metal cap is bonded to each other by forming a groove by half-etching in the cut portion when the metal plate is cut into pieces. Since the surface roughness of at least a part of the surface of the metal cap can be made larger than the surface roughness of the bottom surface of the metal cap, the sealing to the outer surface of the metal cap formed by etching when the sealing resin is applied to the metal cap. The wettability of the stop resin is improved, so that a bonding area between the outer surface of the metal cap and the sealing resin is increased, and a piezoelectric oscillator having a high adhesion strength of the metal cap can be obtained.

  In addition, by forming the grooves used when cutting the metal plate into pieces by half etching, the thickness of the metal plate when cutting into pieces can be reduced, and the load on the equipment can be reduced. Thus, it is possible to obtain a piezoelectric resonator with a higher accuracy of the outer dimensions as compared with the first embodiment.

  In the above embodiment, the surface roughness Ra of the inner surface of the metal cap and the surface roughness Ra of the outer surface of the metal cap formed by half-etching are 10 μm. However, the surface roughness of the inner surface of the metal cap is 10 μm. The surface roughness Ra of the outer surface of the metal cap formed by Ra and half-etching is 1 μm or more, and the sealing resin to the inner surface of the metal cap and the outer surface of the metal cap when the sealing resin is applied to the metal cap Therefore, the surface roughness Ra of the inner surface of the metal cap and the surface roughness Ra of the outer surface of the metal cap formed by half-etching are preferably 1 μm or more.

  Further, in the above embodiment, the dimensions of the capacitor substrate are 3.2 mm in length and 1.3 mm in width, and the dimensions of the metal cap corresponding to this are mentioned, but the piezoelectric oscillation using metal caps of other sizes Similar effects can be obtained in the child.

  In the above embodiment, stainless steel is used as the material of the metal cap. However, even if a metal cap mainly composed of aluminum, iron-nickel alloy, copper, or the like is used, the effect that the fixing strength can be increased is obtained. The same effect can be obtained by using a metal cap that has been subjected to a surface treatment such as forming a film on the surface.

  In the above embodiment, the piezoelectric oscillator has been described as an example. However, the same effect can be obtained in a piezoelectric resonant component such as a piezoelectric filter.

  According to the piezoelectric resonant component and the manufacturing method thereof according to the present invention, the fixing strength of the metal cap can be improved, which is particularly useful for manufacturing a piezoelectric resonant component such as a piezoelectric oscillator and a piezoelectric filter.

DESCRIPTION OF SYMBOLS 11 Capacitance board | substrate 12 Conductive adhesive 13 Piezoelectric resonance element 14 Sealing resin 15 Metal cap 15a Metal cap bottom surface 15b Metal cap inner side surface 15c Metal cap outer side surface 15d Metal cap upper surface 16 Terminal electrode 16a Terminal electrode 16b of substrate upper surface 16b Terminal electrode 16c Terminal electrode on the lower surface of the substrate 17 Internal electrode 18 Vibration confining electrode 19 Half-etched metal plate 20 Groove 21 Cutting allowance 25 Metal cap 25a Metal cap bottom surface 25b Metal cap inner side surface 25c Metal cap outer surface 25d Metal cap upper surface 25e Etching Metal cap outer surface formed by performing 35 metal cap

Claims (6)

A substrate made of an insulating material having terminal electrodes formed on at least the upper surface, a piezoelectric element mounted on the upper surface of the substrate, and a metal fixed to the upper surface of the substrate via a sealing resin so as to seal the piezoelectric element A piezoelectric resonant component comprising: a cap, wherein the metal cap is formed by half-etching a metal plate and has a bottom surface on the same plane. 2. The piezoelectric resonant component according to claim 1, wherein the surface roughness of the inner surface of the metal cap is rougher than the surface roughness of the bottom surface of the metal cap. 3. The piezoelectric resonant component according to claim 2, wherein the surface roughness of at least a portion to which the sealing resin on the outer surface of the metal cap adheres is rougher than the surface roughness of the metal cap bottom surface. The piezoelectric resonant component according to any one of claims 1 to 3, wherein the metal cap is made of stainless steel. Mounting a piezoelectric element on a substrate made of an insulating material having at least a terminal electrode formed on the upper surface, and fixing a metal cap on the upper surface of the substrate with a sealing resin so as to seal the piezoelectric element. And the metal cap is manufactured by half-etching a metal plate. The metal cap is manufactured by half-etching a metal plate and cutting it into individual pieces. A groove formed by half-etching is formed in a cut portion when the metal plate is cut into individual pieces. A method for manufacturing a piezoelectric resonant component according to claim 5.

Images