JP3979121B2 - Manufacturing method of electronic parts - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention, for example, relates to a process for the production of electronic components for electronic component element is accommodated in a package consisting of a case substrate and the cap, such as a piezoelectric resonator, and more particularly, the structure of the portion where the electrodes are provided on the case substrate the method for producing an improved electronic components.
[0002]
[Prior art]
Conventionally, various electronic components having a structure in which an electronic component element is mounted on a case substrate and the electronic component element is surrounded by a conductive cap have been proposed.
[0003]
For example, Japanese Utility Model Laid-Open No. 5-33536 discloses an electronic component 101 shown in FIG. The electronic component 101 includes a substrate 102 and a conductive cap 103. On the substrate 102, terminal electrodes 104, 105, and 106 are formed for electrical connection with the outside.
[0004]
In the conductive cap 103, electronic component elements (not shown) electrically connected to the terminal electrodes 104 to 106 are accommodated. The electronic component element is electrically connected to the terminal electrodes 104 to 106 and fixed on the substrate 102.
[0005]
The conductive cap 103 is provided not only for protecting the electronic component element but also for electromagnetically shielding the electronic component element. The conductive cap 103 is bonded to the upper surface of the substrate 102 by the insulating adhesive 107, but it is necessary to prevent a short circuit between the conductive cap 103 and the terminal electrodes 104 to 106.
[0006]
Therefore, in the electronic component 101, notches 103a to 103c are formed at the lower end edge of the conductive cap 103, and the terminal electrodes 104 to 106 pass through the notches 103a to 103c.
[0007]
[Problems to be solved by the invention]
In the electronic component 101, a short circuit between the conductive cap 103 and the terminal electrodes 104 to 106 is prevented by the notches 103 a to 103 c provided in the conductive cap 103. However, in order to prevent a short circuit between the conductive cap 103 and the terminal electrodes 104 to 106 with such a structure, a conductive cap having a notch corresponding to the position of the terminal electrode must be prepared for each electronic component. In other words, the manufacturing cost has been high.
[0008]
In addition, when the conductive cap 103 is bonded to the upper surface of the substrate 102, the bonding operation must be performed so that the notches 103a to 103c are accurately aligned with the positions where the terminal electrodes 104 to 106 are formed. It was. Therefore, the process of attaching the conductive cap 103 to the substrate 102 is complicated.
[0009]
Not only that, but with the progress of miniaturization of electronic components, the size of the conductive cap 103 is also decreasing. Accordingly, the plurality of notches 103a to 103c must be formed in the small conductive cap 103 with high accuracy without contact with each other. Therefore, it has been difficult to cope with downsizing of electronic components.
[0010]
The object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, to easily and reliably prevent a short circuit between the conductive cap and the terminal electrode on the substrate, and to be easy to manufacture and downsize. corresponding also to provide a method of manufacturing easy electronic components.
[0011]
[Means for Solving the Problems]
[0014]
The method of manufacturing an electronic component according to the present invention includes a step of preparing a case substrate in which a plurality of recesses are formed so as to cross the upper surface, and an electrode having a height lower than the upper surface is formed in the plurality of recesses. And mounting an electronic component element on the case substrate, and bonding a conductive cap to the upper surface of the substrate so as to surround the electronic component element and straddle the recess , The step of preparing the case substrate includes a step of preparing a laminate formed by laminating a plurality of ceramic green sheets, a step of forming the electrode on the upper surface of the laminate, and a laminate having the electrode formed thereon. Pressing in the thickness direction and embedding the electrode on the upper surface of the laminate so that the upper surface of the electrode is exposed; and firing the laminate after the pressing step. Accordingly, since the amount of shrinkage of ceramic during firing is greater than the electrode, Ru can be easily top to place an electrode to be lower than the case the upper surface of the substrate.
[0016]
In another specific aspect of the manufacturing method according to the present invention, the step of mounting the electronic component element on the case substrate joins the electronic component element to the electrode of the case substrate using a conductive bonding agent, and This is done by electrical connection.
[0017]
In still another specific aspect of the manufacturing method according to the present invention, a piezoelectric resonator is used as the electronic component element.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be clarified by describing specific embodiments of the present invention.
[0019]
FIG. 1 is an exploded perspective view of an electronic component according to an embodiment of the present invention. FIG. 2 (a) is a front sectional view and FIG. 2 (b) is a front view.
The electronic component 1 includes a case substrate 2, an electronic component element 3, and a conductive cap 4.
[0020]
In this embodiment, the case substrate 2 is configured by a rectangular plate-shaped ceramic substrate. A plurality of recesses 2 b and 2 c are formed on the upper surface 2 a of the case substrate 2. The recesses 2b and 2c are formed so as to reach both ends of the case substrate 2 in the width direction.
[0021]
Terminal electrodes 5 and 6 are formed in the recesses 2b and 2c. The upper surfaces of the terminal electrodes 5 and 6 are set lower than the upper surface 2 a of the case substrate 2. The terminal electrodes 5 and 6 are formed not only in the recesses 2b and 2c but also on the pair of side surfaces 2d and 2e of the case substrate 2 to reach the lower surface 2f of the case substrate 2. As shown in the perspective view seen from the lower surface side in FIG. 3, the terminal electrodes 5 and 6 are formed so as to cross the lower surface 2 f of the case substrate 2. Accordingly, the terminal electrodes 5 and 6 are configured to wind the case substrate 2 and are disposed in the recesses 2b and 2c only on the upper surface 2a.
[0022]
However, the recesses 2b and 2c may be formed so as to reach the side surfaces 2d and 2e and the lower surface 2f of the case substrate 2.
Further, the recesses similar to the recesses 2b and 2c may be formed on the lower surface 2f of the case substrate 2 so as to face the recesses 2b and 2c. Can be eliminated.
[0023]
The terminal electrodes 5 and 6 are formed by applying and baking a conductive paste. But you may form with the electrically conductive film formed by metal foil or thin film formation methods, such as vapor deposition or plating.
[0024]
The electronic component element 3 is an energy confinement type piezoelectric resonator using a thickness shear mode. The electronic component element 3 has an elongated rectangular plate-like piezoelectric plate 7. The piezoelectric plate 7 is made of piezoelectric ceramic and is polarized in the length direction. Vibrating electrodes 8 and 9 are formed on the upper and lower surfaces of the piezoelectric plate 7. The vibration electrodes 8 and 9 are opposed to each other via the piezoelectric plate 7 in the center in the length direction of the piezoelectric plate 7. The vibration electrode 8 is extended to the one end surface 7 a side of the piezoelectric plate 7 and has an electrode extension 8 a that reaches the lower surface of the piezoelectric plate 7. The vibration electrode 9 is extended on the lower surface of the piezoelectric plate 7 so as to reach the end surface 7b side opposite to the end surface 7a.
[0025]
The electronic component element 3 is bonded to the terminal electrodes 5 and 6 of the case substrate 2 by the conductive bonding materials 10 and 11. The vibration electrodes 8 and 9 are electrically connected to the terminal electrodes 5 and 6 by the conductive bonding materials 10 and 11, respectively.
[0026]
The conductive bonding materials 10 and 11 are configured to have a certain thickness so as to provide a gap between the upper surface 2a of the case substrate 2 so as not to hinder the vibration of the piezoelectric vibration portion of the electronic component element. . That is, as shown in FIG. 2A, the gap A is provided between the upper surface 2 a of the piezoelectric substrate 2 and the electronic component element 3 in a state where the electronic component element 3 is mounted on the case substrate 2. .
[0027]
In this embodiment, the conductive cap 4 is made of a metal material such as aluminum or copper. But the electroconductive cap 4 may consist of insulating materials, such as ceramics and plastics, and the electrically conductive film may be formed in the surface.
[0028]
The conductive cap 4 is bonded onto the case substrate 2 with an adhesive 12 shown in FIG. The conductive cap 4 has an opening on the lower side, and the lower opening edge 4a is joined to the upper surface 2a of the case substrate 2, but the terminal electrodes 5 and 6 are located above the upper surface 2a of the case substrate 2. Located below. Therefore, conduction between the terminal electrodes 5 and 6 and the conductive cap 4 can be reliably prevented.
[0029]
In addition, as the conductive cap 4, a conventionally used conductive cap having no notch or the like can be used. In addition, when the conductive cap 4 is joined to the case substrate 2, it is only necessary to arrange the conductive cap 4 on the upper surface 2a so that the electronic component element 3 can be securely stored. do not need.
[0030]
In addition, even when downsizing of the electronic component 1 is promoted, it is not necessary to provide a plurality of notches in the conductive cap 4, and therefore it is possible to easily cope with downsizing.
As the adhesive 12, it is preferable to use a thermosetting adhesive having a viscosity at 25 ° C. of 100 Pa · s or less, whereby the conductive cap 4, the upper surface 2 a of the case substrate 2, and the terminal electrode 5 are used. , 6 can be reliably sealed with the insulating adhesive 12.
[0031]
As described above, according to the electronic component 1 of the present embodiment, when the conductive cap 4 is joined to the case substrate 2, the terminal electrodes 5 and 6 and the conductive cap 4 can be easily and reliably insulated. Can do. By the way, the method for manufacturing the case substrate 2 is not particularly limited, but the manufacturing method shown in FIGS. 4 and 5 is preferably used.
[0032]
That is, as shown in FIG. 4A, a mother laminate 21 in which a plurality of ceramic green sheets are laminated is prepared. As the ceramic green sheet constituting the mother laminate 21, a lath ceramic sheet that can be fired at a low temperature of 1000 ° C. or lower is preferably used. As a result, the case substrate can be obtained by low-temperature firing, and since the shrinkage amount upon firing is large as described later, the terminal electrodes 5 and 6 can be more reliably positioned below the upper surface of the case substrate. it can.
[0033]
As shown in FIG. 4A, terminal electrodes 5 and 6 are formed by screen printing a conductive paste on the upper surface of the mother laminate 21. Thereafter, as shown by an arrow in FIG. 4B, a pressing step of pressing the laminated body 21 in the thickness direction is performed. By this pressing step, the terminal electrodes 5 and 6 are embedded in the upper surface 21a of the multilayer body 21 so that the upper surfaces of the terminal electrodes 5 and 6 are exposed.
[0034]
Thereafter, the mother laminate 21 is cut into a laminate of two individual case substrates.
In this way, the laminate 22 of the case substrate 2 unit before firing shown in FIG. 5A is obtained. By firing the laminate 22, the case substrate 2 is obtained as shown in FIG. By firing, the conductive paste for constituting the laminate 22 and the terminal electrodes 5 and 6 contracts. However, the material of the multilayer body 22 and the conductive paste is selected so that the contraction amount of the multilayer body 22 is larger than the contraction amount of the conductive paste. Therefore, after firing, in the case substrate 2 having a reduced thickness, the recesses 2b and 2c are formed, and the upper surfaces of the terminal electrodes 5 and 6 are positioned below the upper surface 2a of the case substrate 2. . Thus, the terminal electrodes 5 and 6 in the position where the upper surface is lower than the upper surface 2a can be easily formed by using the ceramic laminated integrated firing technique.
[0035]
However, after the ceramic green sheet laminate 21 is prepared, grooves are formed by pressing or the like, and after the conductive paste is printed in the grooves, the case substrate 2 and the terminal electrodes 5 and 6 are formed by firing. May be.
[0036]
Further, after forming the recesses 2b and 2c by machining or the like on the upper surface of a flat case substrate made of sintered ceramics or made of an insulating material such as plastic, the terminal electrodes 5 and 6 may be formed. Good.
[0037]
In the above embodiment, the energy confining type piezoelectric resonator is used as the electronic component element. However, the electronic component element housed in the package constituted by the substrate and the conductive cap is other than the piezoelectric resonator. It may be an electronic component element.
[0038]
Further, in the above-described embodiment, the recesses 2b and 2c are formed so as to extend in the width direction of the rectangular plate-shaped case substrate 2. A recess may be formed across.
[0039]
【The invention's effect】
[0041]
In accordance with the present invention is formed with a plurality of recesses across the upper surface of the substrate, after preparing the case substrate upper surface height than the substrate is lower electrodes are formed in the recess An electronic component is mounted on the case substrate, and a conductive cap is bonded to the upper surface of the substrate so as to surround the electronic component element. Since the conductive cap has no notch and the electrode on the top surface of the case substrate is located lower than the top surface of the case substrate, the conductive cap is bonded to the top surface of the case substrate without performing a complicated positioning process. can do. Moreover, according to the present invention, it is possible to reliably prevent a short circuit between the conductive cap and the electrode on the upper surface of the case substrate.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of an electronic component according to an embodiment of the present invention.
FIGS. 2A and 2B are a front sectional view and a front view of an electronic component according to an embodiment of the present invention.
FIG. 3 is a perspective view of a case substrate used in an embodiment of the present invention as viewed from the lower surface side.
FIGS. 4A and 4B are cross-sectional views showing a process of forming a plurality of terminal electrodes on a laminated body of a mother ceramic green sheet and a mother laminated body in order to obtain a mother case substrate; Each front sectional drawing for demonstrating the process of embedding a terminal electrode in the upper surface of a laminated body by pressing.
FIGS. 5A and 5B are a front sectional view showing a laminated body of individual case substrate units obtained by cutting the laminated body in one embodiment of the present invention, and firing the laminated body. Front sectional drawing which shows the case board | substrate obtained by doing.
FIG. 6 is a partially cut perspective view for explaining an example of a conventional electronic component.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Electronic component 2 ... Case board | substrate 2a ... Upper surface 2b, 2c ... Recessed part 2d, 2e ... Side surface 2f ... Lower surface 3 ... Electronic component element 4 ... Conductive cap 5, 6 ... Terminal electrode 21 ... Laminated body 22 ... Laminated body

Claims (3)

Preparing a case substrate in which a plurality of recesses are formed so as to cross the upper surface, and an electrode having a lower height than the upper surface is formed in the plurality of recesses;
Mounting an electronic component element on the case substrate;
Bonding a conductive cap to the upper surface of the substrate so as to surround the electronic component element and straddle the recess ,
The step of preparing the case substrate includes a step of preparing a laminate formed by laminating a plurality of ceramic green sheets;
Forming the electrode on the top surface of the laminate;
A pressing step of pressing the laminated body in which the electrodes are formed in the thickness direction and embedding the electrodes on the upper surface of the laminated body so that the upper surface of the electrode is exposed;
Wherein after the pressing step, that having a the step of firing the laminate, the method of manufacturing an electronic component. Wherein the step of mounting the electronic component element to the case substrate, by using a conductive bonding agent to bond the electronic component element to the electrode of the case substrate, and is performed by electrically connecting, in claim 1 The manufacturing method of the electronic component of description. The piezoelectric resonator is used as an electronic component device, method for manufacturing the electronic component according to claim 1 or 2.

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