JP2007311433A - Stem for electronic device, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stem for electronic devices for preventing glass cracks and glass hemispherical sections from falling off due to the operation of shear stress to stand-off glass. <P>SOLUTION: A through-hole 1a provided at a base 1 has the stand-off glass 3. The stand-off glass 3 has a glass columnar section 3b inside the through-hole 1a, and the glass hemispherical section 3a projecting hemispherically from the main surface of the base 1. The glass columnar section 3b and the glass hemispherical section 3a continue essentially in the same outer diameter shape; thus preventing shear stress from operating on one portion of the stand-off glass 3 concentrically, and preventing the cracks and glass hemispherical section 3a from falling to the stand-off glass 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a stem for an electronic device and a manufacturing method thereof, and particularly relates to a technology for a stem for an electronic device having a stand-off glass.

  2. Description of the Related Art Conventionally, some electronic device stems used for a base portion of an electronic device have a standoff glass. This is formed by projecting standoff glass on the lower surface (mounting substrate side) of the base of the stem for the electronic device, and when the electronic device is mounted on the mounting substrate or the like, the standoff glass is brought into contact with the mounting substrate. Thus, the base of the stem for the electronic device is mounted at a certain distance from the mounting substrate so that the base portion of the electronic device does not directly contact the mounting substrate.

  Conventional stems for electronic devices include those disclosed in Patent Document 1 and Patent Document 2, for example. FIG. 3 is a cross-sectional view showing an example of a conventional stem for an electronic device, wherein 100 is a base, 100a is a through hole, 101 is a stand-off glass, 101a is a glass hemispherical part, 101b is a glass corner part, and 101c is a glass columnar part. Respectively.

  As shown in FIG. 3, the standoff glass 101 is disposed by sealing in the through hole 100 a of the base 100, and the glass hemispherical portion 101 a of the standoff glass 101 protrudes to the outer surface (mounting substrate side) of the base 100. Is formed. The glass hemisphere 101a swells to an outer diameter larger than the inner diameter of the through hole 100a.

  According to this configuration, the glass hemispherical portion 101a protruding from the base 100 contacts the mounting substrate (not shown), so that the base 100 maintains a gap corresponding to the glass hemispherical portion 101a between the mounting substrate and the mounting substrate. To be implemented.

  Here, a method of sealing the standoff glass 101 in the through hole 100a of the base 100 will be described. The base 100 is made of an iron-based alloy such as iron-nickel. The base 100 is assembled in a jig with a soft glass tablet inserted into the through hole 100a of the base 100.

  Next, the base 100 together with the jig is passed through a sealing furnace to heat the base 100 and the glass tablet. The melted glass fills the through hole 100a of the base 100 and rises hemispherically on the substrate mounting surface side of the base 100 to form a glass hemispherical portion 101a.

  When the temperature drops after passing through the sealing furnace, the glass is solidified to form the stand-off glass 101, and the base 100 clamps the stand-off glass 101 due to the difference in thermal expansion coefficient between the glass and the metal. The force acts, and the stand-off glass 101 is sealed in the through hole 100a by a so-called compression type mechanical stress. The base 100 is usually plated with nickel having a thickness of about 1 to 5 μm for the purpose of preserving.

  In the electronic device stem described above, the glass hemispherical portion 101 a of the stand-off glass 101 has an outer diameter larger than the inner diameter of the through hole 100 a of the base 100. Therefore, a glass corner portion 101b is formed at the boundary between the glass columnar portion 101c that seals the stand through hole 100a and the glass hemispherical portion 101a of the standoff glass 101 along the opening edge of the through hole 100a.

  The mechanical stress concentration described above occurs on the glass corner portion 101b, and cracks are generated from the glass corner portion 101b as a starting point due to shear stress. In the worst case, the glass hemispherical portion 101a of the stand-off glass 101 is glass. The columnar part 101c may be sheared and dropped off.

In order to solve this problem, there has been a device in which the shape of the base is devised in order to alleviate the stress concentration on the stand-off glass. This configuration is shown in FIG.
As shown in FIG. 2A, the base 100 is provided with a protruding peripheral edge portion 100b around the opening of the through hole 100a. The protruding peripheral edge portion 100b is formed as a ring-shaped protrusion on the outer surface (mounting board side) of the base 100 so as to surround the opening of the through hole 100a.

  The protruding peripheral edge portion 100b was formed so that the outer peripheral diameter (ridge line portion) thereof matched the outer diameter size of the glass hemispherical portion 101a. Further, the corner portion 100c of the inner wall surface of the projecting peripheral edge portion 100b is chamfered.

Alternatively, as shown in FIG. 2B, there is one in which a thin protruding peripheral portion 100 b is formed by forming a concave groove 100 d around the opening of the through hole 100 a of the base 100.
2A and 2B, since the protruding peripheral edge portion 100b is formed with a thin metal thickness, the base 100 is stand-off at the corner portion 100c of the through hole 100a. The shear stress applied to the glass 101 can be relaxed. For this reason, the single unit of the stem for the electronic device was able to obtain a certain effect in preventing cracks and dropout of the glass hemispherical portion 101a.
JP-A-5-62518 Japanese Patent No. 2658886

  However, with the conventional configuration described above, the concentration of compression stress cannot be completely eliminated, and it is completely possible to prevent the standoff glass from cracking and the glass hemisphere from falling off. There was still a challenge that could not be done.

Moreover, since additional processing was required for the base 100 which is a constituent member, there was a problem that the versatility of a member that could be adopted was lacking.
SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and ensures the versatility of the constituent members, while preventing the occurrence of cracks and glass hemispherical dropouts due to the concentration of shear stress. It aims at providing the manufacturing method.

  In order to solve the above-described problem, the stem for an electronic device according to the present invention includes a standoff glass in a through hole provided in a base, and the standoff glass is formed from a glass columnar portion in the through hole and a main surface of the base. A glass hemispherical portion protruding in a hemispherical shape is provided, and the glass columnar portion and the glass hemispherical portion are substantially continuous with the same outer diameter.

  With the configuration described above, the portion where the stress concentration occurs is formed by the opening edge of the through hole of the base facing the stand-off glass at the portion where the glass columnar portion and the glass hemisphere portion are substantially continuous with the same outer diameter. Does not exist as an element.

  For this reason, the compression stress that the base exerts on the stand-off glass is dispersed without concentrating on a part of the stand-off glass, so that the glass does not cause glass cracks or glass hemisphere dropout due to the concentration of shear stress. It becomes the stem for the device. Since the base does not need to be specially processed, it becomes a stem for an electronic device that does not impair versatility as a constituent member.

Further, the base is made of a metal containing iron, and the base is provided with at least a plating layer of a nickel plating film on the entire surface including the inner surface of the through hole.
The thickness of the nickel plating film is 5 to 20 μm.

  In the method for manufacturing a stem for an electronic device according to the present invention, a nickel plating film is formed on the entire surface of the base including the inner surface of the through hole formed in the base made of a metal containing iron, and the glass powder and the binder are compressed to temporarily. The fired glass tablet is inserted into the through-hole of the base and the base is assembled in an assembly jig, the base is passed through a sealing furnace together with the assembly jig, and the base and the glass tablet are heated. The glass melted by heating is sealed in the through hole.

  According to the above-described configuration, the iron component is thermally diffused into the nickel plating film layer from the base heated in the sealing furnace. However, the iron component does not reach the surface of the nickel plating film, and iron oxide having high affinity with glass is not distributed on the surface of the nickel plating film.

  For this reason, when the glass tablet is melted and sealed to the base as a stand-off glass, the glass hemisphere may stay inside the through-hole of the base and flow out and spread to the outer surface (wiring board mounting surface) of the base. Absent. As a result, the stand-off glass has a glass hemispherical portion that is substantially concentric and has the same diameter as the through hole of the base.

  Further, the nickel plating film is formed to have a thickness of 5 to 20 μm.

  As described above, according to the present invention, there is no cause of stress concentration in the stand-off glass, cracks can be generated in the stand-off glass, and the glass hemisphere portion of the stand-off glass can be prevented from falling off due to shear. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a stem for an electronic device according to an embodiment of the present invention. In FIG. 1, 1 is a base, 1a is a through hole, 2 is a nickel plating film, 2a is a nickel plating film, 2b is a copper plating film, 3 is a stand-off glass, 3a is a glass hemispherical part, and 3b is a glass columnar part. Show.

  As shown in FIG. 1A, a base 1 made of an alloy containing iron such as iron-nickel has a through hole 1a, and a nickel plating film 2 is applied to the entire surface of the base 1 including the inner surface of the through hole 1a. ing. A stand-off glass 3 is sealed in the through-hole 1a, and the stand-off glass 3 is hemispherical from the glass-like column portion 3b that seals the through-hole 1a and the lower surface (wiring board mounting side) that forms the main surface of the base 1. And a glass hemispherical portion 3a protruding in the direction. In the stand-off glass 3, the glass hemisphere portion 3a and the glass columnar portion 3b are substantially continuous with the same outer diameter.

  According to the above configuration, the stand-off glass 3 has the glass hemisphere portion 3a and the glass column portion 3b that are substantially concentric with the through-hole 1a of the base 1 and are substantially continuous with the same outer diameter. A portion corresponding to the glass corner portion 101b shown in FIG. For this reason, since the compression stress which the base 1 exerts on the stand-off glass 3 is dispersed without concentrating on a part of the stand-off glass 3, the concentration of shear stress does not occur in the stand-off glass 3, and this is caused. The glass crack and the glass hemispherical portion 3a are not dropped off.

Moreover, since the base 1 does not require special processing, it can be a stem for an electronic device that does not impair versatility as a member.
A method for manufacturing the stem for the electronic device will be described below. The entire surface of the base 1 including the inner surface of the through hole 1 a of the base 1 is covered with the nickel plating film 2. The thickness of the nickel plating film 2 is about 5 to 20 μm, more preferably about 8 to 12 μm.

  Next, a glass tablet of a predetermined volume obtained by compressing and pre-baking glass powder and a binder is inserted into the through hole 1a of the base 1, and in this state, the base 1 is incorporated into an assembly jig made of carbon.

  Then, the base 1 together with the assembly jig is passed through a sealing furnace, the base 1 and the glass tablet are heated to about 1000 ° C., and the melted glass tablet is sealed in the through hole 1 a of the base 1.

  According to said structure, the iron component which the base 1 has is thermally diffused in the layer of the nickel plating film 2 by the heating in a sealing furnace. However, the iron component does not reach the surface of the nickel plating film 2, and iron oxide having high affinity with glass is not distributed on the surface of the nickel plating film 2.

  For this reason, when the glass tablet is melted and sealed to the base 1 as the standoff glass 3, the glass hemispherical portion 3a remains inside the through hole 1a of the base 1, and the outer surface of the base 1 (wiring board mounting surface). It does not flow out and spread. As a result, the stand-off glass 3 has a shape in which the glass hemisphere portion 3a and the glass-like column portion 3b are substantially concentric with the through-hole 1a of the base 1 and substantially have the same outer diameter.

  In the embodiment of the present invention, the plating film applied to the base 1 has been described as a single layer of the nickel plating film 2, but the present invention is not limited to this. For example, as shown in FIG. 1B, a copper plating film 2b and a nickel plating film 2a can be laminated and combined, or a plurality of plating films including the nickel plating film 2a may be used.

  The present invention is useful as a stem for an electronic device, and is particularly suitable for an electronic device stem having a stand-off glass.

Sectional drawing of the stem for electronic devices in embodiment of this invention Sectional view of a conventional stem for electronic devices Sectional view of a conventional stem for electronic devices

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base 1a Through-hole 2 Nickel plating film 2a Nickel plating film 2b Copper plating film 3 Stand-off glass 3a Glass hemisphere part 3b Glass columnar part 100 Base 100a Through-hole 100b Protruding peripheral part 100c Corner part 100d Concave groove 101 Stand-off glass 101a Glass hemisphere part 101b Glass corner part 101c Glass columnar part

Claims (6)

The through-hole provided in the base is provided with a stand-off glass, and the stand-off glass has a glass columnar part in the through-hole and a glass hemispherical part protruding in a hemispherical shape from the main surface of the base, and the glass columnar part, The stem for an electronic device, characterized in that the glass hemisphere portion is substantially continuous with the same outer diameter. 2. The stem for an electronic device according to claim 1, wherein the base is made of a metal containing iron, and the base is provided with at least a plating layer of a nickel plating film on the entire surface including the inner surface of the through hole. The stem for an electronic device according to claim 2, wherein the thickness of the nickel plating film is 5 to 20 µm. An electronic device using the stem for an electronic device according to claim 1. A nickel plating film is formed on the entire surface of the base including the inner surface of the through hole formed in the base made of a metal containing iron, and a glass tablet obtained by compressing and pre-baking glass powder and a binder is inserted into the through hole of the base. Then, the base is assembled into an assembly jig, the base together with the assembly jig is passed through a sealing furnace, the base and the glass tablet are heated, and the glass melted by the heating is sealed in the through hole. A method for manufacturing a stem for an electronic device. 6. The method for manufacturing a stem for an electronic device according to claim 5, wherein the nickel plating film is formed to have a thickness of 5 to 20 [mu] m.

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