JPS6273648A - Hermetic glass terminal - Google Patents

Abstract

PURPOSE:To improve the hermetic properties and the heat dissipating properties, by sealing an eyelet with glass through an iron oxide produced on a metal coating film. CONSTITUTION:A coating film 22 of a metal which can produce an iron oxide, for example an iron plated film, an iron-nickel-cobalt alloy plated film or an iron-cobalt alloy plated film is formed on the surface of an eyelet 10 which is to be sealed with hard glass 14. After the coating film 22 is heated in the atmosphere of an oxide to produce an iron oxide on the film 22, the eyelet is sealed with the hard glass 14. A lead line 12 and an earth lead line 16 which are also sealed with the hard glass 14 are also coated previously with a metal oxide film by means of the oxidation. The eyelet 10 is formed of copper-tungsten alloy, which has a rate of thermal expansion relatively close to that of the hard glass 14. Further, the adhesion properties between the glass 14 and the iron oxide is extremely high. Accordingly, desirable hermetic properties and desirable heat dissipating properties can be obtained even after the heating treatment.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a hermetic glass terminal.

(Prior Art) An airtight glass terminal for a semiconductor device mounting an optical element such as a semiconductor laser element is required to have excellent airtightness and heat dissipation properties in order to satisfy the characteristics of the optical element. In particular, in recent years, with the miniaturization of airtight glass terminals and the increase in the output of mounted elements, excellent heat dissipation properties are particularly required.

By the way, there are generally two types of airtight glass terminals: matt type and compression type.

In general, a matted type airtight glass terminal uses an iron-niso-cobalt alloy as the material for both the eyelet (metallic outer ring) and the lead wire, and hard glass is used for the glass that fixes the lead wire.

In addition, the compression type airtight glass terminal uses soft steel for the eyelet and 5270I (iron-nickel alloy) for the lead wire.
, and soft glass is used for the glass that fixes the lead wires.

Among these, the matt type airtight glass terminal has an eyelet made of an iron-nickel-cohard alloy, and a metal oxide film (Fo: +04 or Coo, FezO*, etc.) is formed on the lead wire to improve the wettability of the glass. Since it is welded, it has excellent airtight properties.

However, the optical element is fixed on the eyelet via a copper heat sink or directly, and heat dissipation is achieved through the copper heat sink and eyelet, but the material of the matte type eyelet is The thermal conductivity of iron-Nisokeru-Cohardt alloy is 0.04 cal/se
The thermal conductivity of mild steel, which is the material of the compression type eyelet, is as low as c - cm = deg, and is 0.18c.
Since the al/sec-cm-deg is low, there is a problem that the heat dissipation property is poor.

In order to improve this heat dissipation, we used a copper-tungsten alloy with high thermal conductivity (thermal conductivity of 0.5~
0.7 cal/sec-cm-deg) is known (Japanese Patent Application Laid-Open No. 60-868).
No. 78).

However, when using copper-tungsten alloy for the eyelet, iron-nickel-cobalt alloy for the lead wire, and hard glass for the glass, this copper-tungsten alloy is made of iron or iron-based Unlike alloys, it cannot form a high-quality metal oxide film that improves the wettability of glass.

Therefore, since the adhesion between the glass and Aireno [. There is a problem.

Aireno is also a type similar to the so-called compression type!・Copper-tungsten alloy, iron lead wire
When using nickel alloy and soft glass,
t] 4-Since the coefficient of thermal expansion of tungsten alloy is smaller than that of soft glass, airtightness is achieved by compressive stress.
This is extremely difficult.

Therefore, when a copper-tungsten alloy is used for the eyelet, the airtightness between the eyelet and the glass is affected by the thermal expansion caused by heating (approximately 400 to 450°C) when the optical element is fixed to the eyelet or heat sink. Significantly inhibited.

The present invention has been made in view of the above problems, and its purpose is to provide an airtight glass terminal that has excellent airtightness and heat dissipation properties even after heating to over 400°C when fixing an optical element. It is in.

(Summary of the Invention) In order to achieve the above object, the present invention includes the following configuration.

That is, in an airtight glass terminal in which a lead wire is sealed to an eyelet using glass, the eyelet is made of copper.
Tungsten alloy is used for the surface that comes into contact with the glass.
A metal film on which iron oxide can be formed is formed on the surface of iron plating, iron-nickel alloy plating, etc., and the glass is sealed via the iron oxide formed on the metal film. Features.

(Example) Hereinafter, preferred embodiments embodying the present invention will be described in detail based on the accompanying drawings.

In FIG. 1(a), 10 is an eyelet, and copper-
Tungsten alloy is used.

Reference numeral 12 denotes a glued wire made of an iron-nisogel-cobalt alloy, which is electrically insulated and sealed to the eyelet 10 by a hard glass 14.

Reference numeral 16 denotes a ground wire made of an iron-cobalt alloy, which is electrically connected to and fixed to the eye μ node 10.

An optical element 18 is fixed on the eyelet 10 with a gold-silicon eutectic alloy or the like, and is connected to the tip of the lead cotton 12 by a metal wire 20. Furthermore, eyelet 1
A suitable cap, optical connector, etc. (not shown) are fixed on the 0.

FIG. 1(b) shows another embodiment in which the shape of the eyelet is different.

A characteristic feature of the present invention is that the sealing surface of the eyelet 10 with the hard glass 14 is coated with a metal coating that can generate iron oxides, such as iron plating, iron-nisokeru-cohard alloy plating, iron-cohard alloy plating, etc. 22 is formed, heated in an oxidizing atmosphere (oxidation treatment) to form iron oxide on the metal film 22, and then sealed with hard glass 14.

The sealing with the hard glass 14 is preferably performed in a neutral atmosphere at 1000°C.

Note that it is natural to apply a metal oxide film on the lead wire 12 and the ground wire 16 which are sealed to the hard glass 14 by oxidation treatment in advance.

In addition to the above-mentioned metal coating, as shown in Fig. 2, iron plating 24 is used.
Two-layer plating with and nickel plating 26, or three-layer plating with iron plating 24, Ni-Nokel plating 26, and cobalt plating 28 as shown in Figure 3, or iron plating 24 and cobalt plating 28 as shown in Figure 4. It may also be multilayer plating containing iron, such as two-layer plating. In this case, even if iron plating is present in the lower layer, the heating during the oxidation treatment will partially diffuse the iron component to the surface, making it possible to form high-quality iron oxide.

Note that the metal film may be formed by plating, sputtering, etc. in addition to being formed by plating.

The coefficients of thermal expansion of the copper-tungsten alloy that is the material of the eyelet 10, the iron-Nisokeru-Cohardt alloy that is the material of the lead wire 12 and the ground lead wire 16, and the hard glass 14 are relatively close to each other. Since the adhesion with the oxide is extremely strong, the airtightness is maintained extremely well even after heating when fixing the optical element.

Of course, as mentioned above, copper-tungsten alloy has a much higher thermal conductivity than conventional soft steel or iron-nickel-cohard alloy, so it is at least 2 to 5
An airtight terminal with twice as good heat dissipation properties was obtained.

It should be noted that the present invention is not limited to applications for optical devices, but can of course be applied to airtight glass terminals that particularly require 3" dissipation properties.

(Effects of the Invention) As described above, the airtight glass terminal according to the present invention has
It has the remarkable effect of maintaining both airtightness and heat dissipation properties even after undergoing a thermal history due to heating.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an example of an airtight glass terminal according to the present invention, and FIGS. 2 to 4 are explanatory cross-sectional views showing other examples of the plating film formed on the eyelet surface. IO...eyelet, 12...lead wire,
14...Hard glass, 16...Earth lead cotton, I8...Optical element, 20...Metal wire, 22...Metal coating, 24...Iron plating,
26...Nickel plating, 28...Cobalt plating.

Claims (1)

[Claims] 1. In an airtight glass terminal in which a lead wire is sealed to an eyelet using glass, the eyelet is made of a copper-tungsten alloy, and the surface in close contact with the glass is coated with iron plating or iron-tungsten alloy. An airtight glass characterized in that a metal film on which iron oxide can be formed is formed on the surface of nickel alloy plating, etc., and the glass is sealed via the iron oxide formed on the metal film. terminal.