JP2006128287A - Electronic component and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic component which provides stable characteristics even if a brazing material for bonding a seam ring and a solvent remaining in the brazing material are remelted, and to provide its manufacturing method. <P>SOLUTION: In the electronic component where an electronic component element 2 is mounted on the upper surface of a substrate 1, the seam ring 3 is bonded to the upper surface of the substrate 1 with the brazing material 5 so as to surround the electronic component element 2, and a metal cover 4 is joined with the upper part of the seam ring 3 by welding to hermetically seal the electronic component element 2, a groove 6 surrounding the lower surface of the seam ring 3 is formed and the brazing material 5 is formed in a region outside the groove 6. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electronic component in which an electronic component element such as a piezoelectric element is hermetically sealed and a method for manufacturing the same.

  Conventionally, an electronic component in which an electronic component element such as a piezoelectric element is hermetically sealed has been used in many applications.

  For example, as shown in FIG. 4, such a conventional electronic component has an electronic component element 52 mounted on the upper surface of a substrate 51, and a seam ring 53 is placed on the upper surface of the substrate 51 with a brazing material 55 so as to surround the electronic component element 52. The electronic component element 52 is hermetically sealed by welding a metal lid 54 to the upper part of the seam ring 53 (see, for example, Patent Document 1).

  The electronic component is manufactured by a manufacturing method including the following steps.

First, the substrate 51 and the seam ring 53 are prepared, and the upper surface of the substrate 51 and the lower surface of the seam ring 53 are joined by the brazing material 55. Next, after the electronic component element 52 is mounted on a region surrounded by the seam ring 53 on the upper surface of the substrate 51, the metal lid 54 is placed on the seam ring 53, and the metal lid 54, the seam ring 53, Are welded to hermetically seal the electronic component element 52 to obtain the conventional electronic component.
Japanese Patent Laying-Open No. 2001-77660 (FIG. 9)

  However, in the above-described conventional electronic component, when the electronic component is mounted on the circuit wiring board, the brazing material 55 and the brazing material which join the seam ring 53 and the substrate 51 when heated in a process such as reflow. The solvent remaining in 55 may reach the electronic component element 52 by being remelted by heat. The brazing material 55 in contact with the electronic component element 52 and the solvent remaining in the brazing material 55 fluctuate the characteristics of the electronic component element 52 and consequently the characteristics of the electronic component.

  Also in the above-described conventional method of manufacturing an electronic component, when the metal lid 54 and the seam ring 53 are welded, the heat applied to the seam ring 53 remelts the brazing material 55 and remelts the brazing material 55. In addition, the solvent remaining in the brazing material 55 may come into contact with the electronic component element 52.

  The present invention has been devised in view of the above-mentioned drawbacks, and the object thereof is an electronic component and an electronic component in which stable characteristics can be obtained even when a solvent remaining in the brazing material and a solder remaining in the brazing material are remelted. It is in providing the manufacturing method of.

  The electronic component of the present invention has an electronic component element mounted on the upper surface of the substrate, a seam ring is joined to the upper surface of the substrate with a brazing material so as to surround the electronic component element, and a metal lid is formed on the upper portion of the seam ring. In an electronic component formed by welding the body and hermetically sealing the electronic component element, a groove portion is formed around the lower surface of the seam ring, and the brazing material is formed in a region outside the groove portion. It is characterized by this.

  The electronic component according to the present invention is characterized in that the groove is formed closer to the inner periphery of the seam ring.

  Furthermore, the electronic component of the present invention is characterized in that a groove on the upper surface side that is plane-symmetric with the groove is formed on the upper surface of the seam ring.

  Furthermore, the method of manufacturing an electronic component according to the present invention includes a step of preparing a substrate and a seam ring in which a groove portion that circulates at least on the lower surface, an upper surface of the substrate, and a region outside the groove portion on the lower surface of the seam ring. Bonding with a brazing material, mounting the electronic component element on a region surrounded by the seam ring on the upper surface of the substrate, and placing the metal lid on the seam ring, the metal lid Welding a body and the seam ring to hermetically seal the electronic component element. A seam ring in which a groove on the upper surface side that is plane-symmetric with the groove may be used on the upper surface.

  According to the electronic component of the present invention, a groove is formed on the lower surface of the seam ring, and the substrate and the seam ring are joined in a region outside the groove, so that the brazing material is not formed near the inner periphery of the seam ring. Therefore, since the solvent remaining in the remelted brazing material when heated by reflowing or the like is less likely to move inward from the groove, the electronic component element is in contact with the brazing material and the solvent remaining in the brazing material. The characteristics are stable without any problem.

  Further, according to the electronic component of the present invention, since the groove portion is set closer to the inner periphery and the area of the joint portion is increased, the joint strength between the substrate and the seam ring is high.

  Furthermore, according to the electronic component of the present invention, since the groove portions are formed on both the upper surface and the lower surface of the seam ring, it is not necessary to check the vertical position of the seam ring during the process.

  Furthermore, according to the method for manufacturing an electronic component of the present invention, since the electronic component element is mounted on the substrate on which the brazing material is not formed near the inner periphery of the seam ring, reflow or the like is performed in the step of mounting the electronic component element. Even when heat is applied, the brazing material and the solvent remaining in the brazing material are remelted, making it difficult to reach the electronic component element. Also, in the process of welding the metal lid, the seam ring and the substrate are joined. The solvent remaining in the brazing material is less likely to remelt by heat and reach the electronic component element, thereby stabilizing the characteristics of the electronic component element.

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

  FIG. 1 is an exploded perspective view of an electronic component according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the electronic component according to an embodiment of the present invention, and FIG. The electronic component shown in FIG. 1 has a structure generally composed of an electronic component element 2, a substrate 1, a seam ring 3, and a metal lid 4.

  The electronic component element 2 is, for example, a piezoelectric element such as a surface acoustic wave element or a quartz crystal vibration element, a semiconductor element, or the like. A fine wiring is formed on the surface of the substrate and has specific characteristics / functions.

  A substrate 1 on which an electronic component element 2 is mounted has a structure in which a plurality of insulating layers are laminated. A conductor pattern 1c is formed on the upper surface so as to circulate, and a recess is formed on the inner side. 1a is formed, and a cavity 10a having a smaller opening is formed in the recess 1a. A conductor pattern 1b whose end is in contact with the opening of the cavity 10a is formed on the opening surface of the cavity 10a, and a conductor pattern 1d is formed on the bottom of the cavity 10a so that a part of the outer peripheral portion is in contact with the inner wall of the cavity 10a. Is formed.

  As the material of the insulating layer constituting the substrate 1, for example, a ceramic material having excellent airtightness such as alumina, mullite, and glass ceramic is used. For the conductor patterns 1b, 1c, and 1d, for example, a metal material such as W or Mo is used. It is done. Note that a plating film such as Au is formed on the surface of the conductor patterns 1b, 1c, and 1d for the purpose of preventing surface oxidation, and an Ni plating film is used as an intermediate layer for the purpose of improving solder heat resistance and wire bonding properties. Is formed. The Au plating film is set to 0.1 to 0.6 μm, and the Ni plating film is set to 1 to 6 μm.

  The electronic component element 2 is accommodated in the cavity 10a with respect to the substrate 1, the lower surface is fixed to the conductor pattern 1d of the substrate 1 using a conductive resin or the like, and the electrode pad formed on the upper surface of the electronic component element 2 2a and the conductor pattern 1b of the board | substrate 1 have the structure bonded by wire bonding.

  The electronic component element 2 is formed by the substrate 1, a seam ring 3 joined to the upper surface of the substrate 1 so as to surround the electronic component element 2, and a metal lid 4 welded and joined to the upper part of the seam ring 3. In a sealed space.

  As the material of the seam ring 3, for example, Kovar is used. Ni plating is formed on the surface by 1 to 6 μm, and Au plating is further formed on the surface by 0.1 to 0.6 μm. For example, Kovar is used as the material of the metal lid 4, and Ni plating is formed on the surface of 1 to 6 μm.

  For joining the substrate 1 and the seam ring 3, a brazing material 5 is used. The brazing material 5 is made of, for example, silver solder or the like, and is formed in a thin layer of, for example, 5 to 30 μm between the conductor pattern 1 c formed on the upper surface of the substrate 1 and the lower surface of the seam ring 3.

  In the electronic component of the present embodiment, the brazing material 5 is formed in a region outside the groove 6 formed so as to circulate on the lower surface of the seam ring 3.

  Further, on the upper surface of the seam ring 3, an upper surface side groove portion 7 (hereinafter simply referred to as a groove portion) 7, which is symmetrical with the lower surface side groove portion 6, is formed.

  As described above, since the substrate 1 and the seam ring 3 are joined in the region outside the groove portion 6 so that the brazing material 5 is not formed in the vicinity of the inner periphery of the seam ring 3, when heated by reflow or the like, The remelted brazing material 5 and the solvent remaining in the brazing material 5 are less likely to move inward from the groove 6, and the electronic component element 2 is not in contact with the solvent remaining in the brazing material 5. Becomes stable.

  Since the groove 6 also has a role of storing the remelted brazing material 5 and the solvent remaining in the brazing material 5, the depth is preferably 10 μm or more and the width is preferably 20 μm or more.

  Further, in the present embodiment, the groove 6 is set inward from the center in the width direction crossing the seam ring 3 to increase the area of the joint, so that the joint strength between the substrate 1 and the seam ring 3 is increased. I made it.

  The electronic component of this embodiment is manufactured by the following manufacturing method.

  (Step A) First, the seam ring 3 in which the substrate 1, the groove portion 6 that circulates on the upper surface and the lower surface, and the groove portion 7 on the upper surface side is prepared.

  The substrate 1 is manufactured, for example, by a conventionally known green sheet method. Specifically, holes corresponding to the cavity 1a are formed using a mold on a ceramic green sheet in which inorganic powder mainly composed of ceramic is dispersed in an organic binder, and the obtained ceramic green sheet is laminated. And then fired.

  Conductor patterns 1b, 1c, and 1d formed on the surface of the substrate 1 are obtained by dispersing metal powder such as W in a vehicle using a screen printing method or the like on a ceramic green sheet when the substrate 1 is manufactured. It is obtained by applying a conductive paste and forming a plating film of Au, Ni or the like on the surface of the metal metallized film formed by firing.

  If the groove portions 6 and 7 are formed on both the upper surface and the lower surface of the seam ring 3, it is not necessary to check the vertical position of the seam ring 3 during the process.

  (Step B) Next, a brazing material 5 such as silver brazing is formed on the upper surface of the substrate 1 on the conductive pattern 1c formed so as to circulate, and the seam ring 3 is placed thereon. The seam ring 3 is joined by heat treatment.

  In the present embodiment, the brazing material 5 is formed in the region of the conductor pattern 1 c corresponding to the region outside the groove 6 on the lower surface of the seam ring 3.

  (Step C) Next, the electronic component element 2 is mounted on a region surrounded by the seam ring 3 on the upper surface of the substrate 1.

  Since the electronic component element 2 is mounted on the substrate 1 on which the brazing material 5 is not formed in the vicinity of the inner periphery of the seam ring 3, the brazing material 5 is applied even when heat due to reflow or the like is applied in the step of mounting the electronic component element 2. In addition, the solvent remaining in the brazing material 5 is remelted and hardly reaches the electronic component element 2.

  (Step D) Then, after placing the metal lid 4 on the seam ring 3, the metal lid 4 and the seam ring 3 are welded to hermetically seal the electronic component element 2 to produce an electronic component. Is done.

  Also in this process, the brazing material 5 that joins the seam ring 3 and the substrate 1 and the solvent remaining in the brazing material 5 are less likely to re-melt by heat and reach the electronic component element 2. The characteristic of 2 is stable.

  Since the four corners of the seam ring 3 have a large amount of heat applied at the time of welding, it is particularly preferable that the groove 6 has a width wider than each side at the four corners of the seam ring 3. Thus, the excessively melted portion can be sufficiently accumulated.

  Thus, the electronic component of the present embodiment, for example, when a surface acoustic wave element is used as an electronic component element, a high frequency filter that selectively passes a specific frequency band when mounted on a circuit wiring board, or a predetermined frequency It functions as a resonator used in a circuit that oscillates.

  In addition, this invention is not limited to the above-mentioned embodiment, A various change and improvement are possible in the range which does not deviate from the summary of this invention.

  For example, in the above-described embodiment, the electronic component element 2 is housed in the cavity 10a formed in the recess 1a. However, the cavity 10a may not be formed, and the recess 1a may not be formed. It doesn't matter.

FIG. 1 is an exploded perspective view of an electronic component according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of an electronic component according to an embodiment of the present invention. FIG. 3 is an enlarged view of a main part of the circle region in FIG. It is sectional drawing of the conventional electronic component.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Board | substrate 1a ... Recessed part 10a ... Cavity 1b, 1c, 1d ... Conductor pattern 2 ... Electronic component element 2a ... Electrode pad 3 ... Seam ring 4 ... Metal lid Body 5 ... brazing material

Claims (4)

An electronic component element is mounted on the upper surface of the substrate, and a seam ring is bonded to the upper surface of the substrate with a brazing material so as to surround the electronic component element, and a metal lid is welded and bonded to the upper portion of the seam ring. In an electronic component formed by hermetically sealing an electronic component element,
An electronic component, wherein a groove portion is formed around the lower surface of the seam ring, and the brazing material is formed in a region outside the groove portion. The electronic component according to claim 1, wherein the groove is formed closer to an inner periphery of the seam ring. The electronic component according to claim 1, wherein an upper surface side groove portion that is plane-symmetric with the groove portion is formed on an upper surface of the seam ring. Preparing a seam ring formed with a substrate and at least a groove that circulates on the lower surface;
Bonding the upper surface of the substrate and the region outside the groove on the lower surface of the seam ring with a brazing material;
Mounting an electronic component element in a region surrounded by the seam ring on the upper surface of the substrate;
A step of hermetically sealing the electronic component element by welding the metal lid and the seam ring after placing the metal lid on the seam ring; and
A method for manufacturing an electronic component comprising:

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