JPH06298551A - Sealing structure - Google Patents

Abstract

PURPOSE:To enable low-pressure sealing bond of copper, to simplify a process, to prevent environmental pollution and to lighten a member by specifying materials of both metals to be sealed and using lead-based glass as sealing glass. CONSTITUTION:Doughnut low-melting sealing glass 3 having a hole 3a composed of lead (Pb0)-based glass having <=700 deg.C sealing temperature is set on a hole 1a of a base plate 1 of a first metal constituted of any of copper, nickel, metal plated with nickel and a nickel alloy having plural holes 1a to seal a lead pin 2 and the lead pin 2 of a second metal made of any of the same material as that of the first metal is set on the hole 3a. Al is laid as a bonding pad for wire bonding of gold, etc., for electrically connecting the lead pin 2 to another part in the interior of the base plate 1 on the top of the lead pin 2. Airtight sealing is carried out by taking advantage of thermal expansion of both the metals in an atmosphere of N2 containing <=1.0ppm oxygen at 500 deg.C for 20 minutes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called hermetic seal in which a metal-to-metal seal is sealed with a glass for sealing, and in particular, an electronic part or an electric part is hermetically sealed.
Metal that maintains insulation between metal terminals, lead pins, etc. and surroundings
Regarding glass bonding.

[0002]

2. Description of the Related Art Conventionally, a glass for sealing has been used for hermetically sealing metal parts (metal case, metal terminal, etc.) such as electronic parts and electric parts, and in particular, a metal base plate. A hermetic seal, in which a metal lead pin is sealed in the through hole formed in the above through the sealing glass, is widely used for metal package of semiconductors and airtight terminal parts such as current terminal outlet of vacuum equipment. It's being used. As the metal material of the member to be sealed which is the airtight terminal component, SPC steel plate, SOS304, Kovar (Fe-Ni-Co alloy) or the like has been used. Further, as the glass for sealing, for example, as disclosed in Japanese Patent Laid-Open No. 3-106077, soda lime type, soda barium type, glass powder of borosilicate etc. is added to some binder to form a granular powder. The high melting point glass is used as a doublet by press-molding and removing the binder, sintering and heat treatment, and the sealing temperature is about 800 to 1200 ° C.

[0003]

When performing hermetic sealing between the metal members to be sealed using the glass for sealing, corrosion resistance when using iron-based materials such as SPC steel plate, SOS304, etc. Since it is necessary to perform nickel (Ni) plating on the surface for the purpose of improvement and protection of the metal surface, the manufacturing process was very complicated. Kovar is also expensive in terms of cost, and has a problem in cost when mass-produced. Also,
When exposed to a high sealing temperature, an oxide is generated on the metal surface, which interferes with solder coating, wire bonding, plating, etc. after sealing. , Alkali etc.) had to be removed. The waste generated by this chemical treatment or the heavy metal components contained in the wastewater are not preferable from the viewpoint of global environmental pollution, and it was necessary to reduce this chemical treatment as much as possible.

From this, it is advisable to use a material other than iron-based material, but even if a material other than iron-based material is used, the high melting point glass is used in the conventional manufacturing process. The sealing temperature is as high as about 1000 ° C., for example, copper having a melting point of about 1065 ° C. cannot be used as a sealing material, and there is a problem that the common materials are limited depending on the sealing temperature.

[0005]

According to the present invention, in a seal structure in which a first metal and a second metal are sealed with a glass for sealing, the two metals are copper (Cu), nickel and nickel. A lead (Pbo) -based glass having a sealing temperature of 700 ° C. or lower was used as the sealing glass, which was either a plated metal or a nickel alloy.

Further, in the seal structure in which the first metal and the second metal are sealed by the glass for sealing, the thermal expansion of the metal material is utilized to hermetically seal the seal. .

[0007]

[Operation] By using a low melting point glass, it is possible to seal at a low temperature, and a copper seal which has been impossible in the past can be obtained. Further, copper has extremely good corrosion resistance as compared with iron-based materials. , Plating for surface protection is unnecessary.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of carrying out the hermetic sealing of the present invention will be described with reference to the embodiments shown in the accompanying drawings. In the following, an example of sealing the base plate (first metal) and the lead pin (second metal) in the pressure sensor and the acceleration sensor is shown.

The base plate 1 which is the member to be sealed is copper.
This base plate 1 is a reel which is another member to be sealed which will be described later.
It has a plurality of holes 1a for sealing the pin 2.

Lead pin 2 is nickel-plated 50
A metal such as a Ni-Fe alloy, a 42Ni-Fe alloy, or Kovar is set in the hole 1a of the base plate 1 through a sealing glass 3 described later.

The glass 3 for sealing is a donut-shaped formed body made of lead glass and having holes 3a, and the holes 1 of the base plate 1 are formed.
The sealing glass 3 is set in a, and the lead pin 2 is set in the hole 3a of the sealing glass 3.

With this structure, the base plate 1 and the lead pin 2 can be sealed with the glass 3 for sealing.
In this case, glass with low melting and softening points (low melting glass)
Since the sealing temperature can be significantly reduced compared to the conventional method (about 500 ° C in the current process),
Copper that could not be used as a sealed member (melting point of about 10
65 ℃) is now available.

Further, since the sealing temperature is low, the other parts (not shown) arranged inside the base plate 1 and the reel are arranged.
Gold (Au) used to make electrical connection with the depin 2
For example, aluminum (Al) having a low melting point can be preliminarily provided on the upper surface of the lead pin 2 in the previous step of performing the sealing as a bonding pad for wire bonding, etc., and the manufacturing process is simplified as a whole. Can be converted.

Next, a specific example actually manufactured by the present invention will be described.

An example in which good results are obtained is shown below. The base plate 1 is a copper plate, and the lead pins 2 are nickel-plated 50 Ni-Fe alloy having a thickness of 5 to 10 μm by an electronickel plating method using a sulfamic acid bath. Glass for sealing 3
In order to give strength by removing the binder such as nitrocellulose and aromatic organic compounds added for pulling after cylindrical press molding of the lead-based glass powder,
The glass tablets (low melting point glass) sintered near the melting point of the sealing glass 3 were used. The sealing was performed at a temperature of 500 ° C. for 20 minutes in a nitrogen atmosphere containing oxygen of 1.0 ppm or less. In addition to this, only the base plate 1 was replaced with a nickel-plated SPC steel plate, and a similar seal was prepared.

For comparison with the examples, the base plate 1
As the conventional nickel-plated SPC steel plate, and the same combination as the lead pin 2 with the same nickel-plated 50Ni-Fe alloy, only the sealing glass 3 is the conventional soda barium (SiO2-BaO-Na2O). Instead of the high melting point glass of the system,
A comparative example (conventional example) was produced in the same atmosphere at a seal temperature of 1000 ° C. for 10 minutes.

As a result of examining the seal state between the manufactured example and the comparative example, the pull-out strength of the lead pin 2 was that the latter pulled out at a load of about 4 kgf. The former was about 4 to 5 kgf, which was equivalent to the strength of the comparative example. Further, even if only the base plate 1 was replaced with nickel-plated SPC steel plate and the pull-out strength was 13 kgf, the lead pin 2 did not pull out, and the seal part broke. In this way, the former pull-out strength is equivalent to the conventional example,
Or even better.

In order to clarify these causes, an attempt was made to observe the bonding interface between the former base plate 1 and the sealing glass 3, and as a result, a SP with nickel plating, which gave a high bonding strength, was obtained.
In the case of C steel sheet, a reaction layer (oxidation-reduction reaction between lead and nickel) is formed at the interface, and lead-based glass (low melting point glass) has a crystal structure that is not the same as before. In addition, SPC steel sheet has a higher coefficient of thermal expansion than that of Kovar, which is generally used as a metal material.
It is presumed to be due to the synergistic effect of a compression seal structure, which is: 40 × 1/10 ⁷ , SPC steel plate: 130 × 1/10 ⁷ ). In the case of copper, since no trace of the reaction layer is observed, it is considered that the reaction layer is mechanically bonded to the sealing glass 3 rather than chemically. That is, since the coefficient of thermal expansion of copper (180 × 1/10 ⁷ ) is larger than that of SPC steel plate, a large compressive force is applied to the sealing part to seal hermetically and a chemical reaction layer is formed. Although the bonding strength was smaller than that of the SPC steel plate with nickel plating by the amount that was not applied, it showed the same drawing strength (about 4 kgf) as the conventional example and there is no practical problem.

Since the sealing temperature is 700 ° C. or less, no scale (rust or oxide) is generated on the base plate 1 and the lead pin 2.

Further, the present invention can be variously modified within the scope of the gist thereof. For example, if the member to be sealed is copper, nickel, a metal plated with nickel, or a nickel alloy. It is possible to seal at a low temperature by using the glass 3 for sealing. It goes without saying that one metal may be copper and the other metal may be copper.

[0021]

The present invention has a seal structure in which a first metal and a second metal are sealed with a glass for sealing, wherein the two metals are copper, nickel and a nickel-plated metal,
It is any of nickel alloys, and the glass for sealing is made of lead-based glass having a sealing temperature of 700 ° C. or less. ) Is possible, and the metal surface treatment such as plating is unnecessary, and the manufacturing process can be greatly simplified. Further, since no oxide is generated in both metals after the sealing, there is no need to perform a chemical treatment, which is very useful in terms of preventing environmental pollution. In addition, the weight of the member to be sealed can be reduced.

[Brief description of drawings]

FIG. 1 is an exploded sectional view showing an embodiment of the present invention.

[Explanation of symbols]

 1 Base plate (first metal) 2 Lead pin (second metal) 3 Sealing glass

Claims (2)

[Claims] 1. In a seal structure in which a first metal and a second metal are sealed with a glass for sealing, the two metals are copper (Cu), nickel (Ni), and nickel plated. A seal structure characterized in that it is either a metal or a nickel alloy, and that the glass for sealing is a lead (Pbo) -based glass having a sealing temperature of 700 ° C. or less. 2. The seal structure according to claim 1, wherein:
A compression seal that hermetically seals by utilizing the thermal expansion of a metal material.
A seal structure characterized by having a seal structure.