JP3269664B2 - Metal member sealing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for sealing metal members. More specifically, the present invention relates to a method of sealing a metal member used for a hermetic seal portion of an electronic component, a sealing portion of a liquid crystal glass, a sealing portion of a laser cap, and the like.

[0002]

2. Description of the Related Art Conventionally, a technique of sealing and sealing electronic parts when manufacturing them is to protect the electronic parts from moisture, outside air, dust, etc., and to secure the reliability of the electronic parts for a long period of time. It has become an indispensable and important technology.

In the above sealing and sealing techniques, a sealing method using low melting point glass is used in various fields such as hermetic sealing, sealing of liquid crystal glass, and sealing of a laser cap.

[0004] As a sealing method using the low melting point glass, the following method can be cited. First, as a normal pre-oxidation step, a metal member such as Kovar is heated in a wet hydrogen atmosphere at 700 to 900 ° C. for 10 to 30 minutes in a furnace so that the weight gain of oxidation is about 0.3 mg / cm ^3. Is performed to form an oxide film. Next, the metal member on which the oxide film is formed and the glass member are assembled via low-melting glass,
Heat treatment at ~ 700 ° C and seal with low melting glass. Thereafter, the oxide film formed by the preliminary oxidation is washed with an acid such as sulfuric acid to remove the oxide film, and then plated to complete the sealing step.

[0005]

In the above-mentioned conventional method, there is a problem that a continuous furnace capable of forming a wet hydrogen atmosphere is required for performing pre-oxidation, and equipment costs are high.

In addition, a low-melting glass or glass member made of a material that can withstand acid cleaning for removing an oxide film is required.
If the material cost is high, and if a material having insufficient corrosion resistance is used, there is a problem that the yield is reduced due to a decrease in sealing property, and the manufacturing cost is increased.

[0007] Furthermore, if the cleaning is insufficient, there is a problem that the yield is reduced due to dirt or the like due to residual cleaning and the manufacturing cost is increased.

[0008] In order to avoid the above-mentioned problem of pre-oxidation, there is a method in which plating of nickel or the like is performed without pre-oxidation, and then sealing is performed with low-melting glass. Wearing is weak and confidentiality cannot be maintained.

On the other hand, for example, there is a method in which the sealing portion is masked and plated, and then the masking member is removed and sealing is performed, but this is not practical because the process becomes complicated.

[0010]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in order to solve the above-mentioned problems, and as a result, it has been found that plating is difficult to be formed on a metal portion in which a concave portion is formed, and a thin mottled plating film having many pinholes. It is found that after plating is performed so that the plating film is hardly adhered to the sealed portion, oxidation of the sealed portion and fusion of the low-melting glass are simultaneously performed.

That is, a method for sealing a metal member according to the present invention is a method for sealing a metal member and a glass plate with a low-melting glass, wherein a concave portion is formed at a sealing portion of the metal member. Forming, plating the metal member with the concave portion formed thereon, disposing a low melting point glass and a glass plate in the concave portion,
Welding is performed in an inert gas atmosphere containing a small amount of oxygen.

According to a second aspect of the present invention, there is provided a method for sealing metal members, wherein the metal members are sealed with a low melting point glass. After each of the recesses is formed, plating is performed on the metal member, and the sealed portions of the two metal members are joined via a low-melting glass, and welded in an inert gas atmosphere containing a small amount of oxygen. And

[0013]

According to the method of sealing a metal member of the present invention, plating is performed after forming a concave portion in the sealed portion of the metal member, so that the sealed portion of the metal member has a mottled plating film having many pinholes. Then, the portion where the plating film is not adhered is oxidized and welded to the low melting point glass. Further, a portion other than the concave portion which is a sealing portion is covered with a uniform plating film on the flat portion, and an oxide film is not formed with a small amount of oxygen at the time of welding, so that there is no need to perform an acid treatment after welding. .

[0014]

Next, the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a manufacturing process of welding a metal member and a glass plate with low melting glass, and FIG. 2 is a diagram showing a manufacturing process of welding a metal member and a metal member with low melting glass.

FIG. 1 is a process diagram for forming a window member of a laser cap, for example, in order to shield a semiconductor laser chip disposed in a case from the outside air and emit a laser beam to be emitted to the outside. The transparent plate is sealed.

First, a concave portion 8 as shown in FIG. 1A is formed in a sealing portion 1d of a metal member made of Kovar material or the like. The recess 8 is for making plating less likely to occur. The smaller the diameter and the deeper it is, the better. However, it is determined in consideration of the purpose of the product. For example, a recess 8 having a diameter D of 3.5 mm and a depth H of 2.1 mm is formed in the metal member 1. Further, the sharper the edge portion a of the concave portion is, the less plating is applied, which is preferable. In the center of this recess, a through hole 1f (1.5 mm in diameter) for forming a window glass for emitting light is provided.
Are formed.

Next, the metal member 1 is subjected to, for example, electrolytic nickel plating. In this plating, when plating is performed on the metal member 1 in which the concave portions 8 are formed as described above, current does not easily flow in the concave portions 8 and the plating film in the concave portions 8 becomes mottled, and particularly, the edge portions a and the bottom portions are formed. In b, the plating film is not sufficiently formed, the number of pinholes increases, and a portion where the plating film is not formed occurs. In order to make it difficult to form the plating film in the concave portion 8, it is possible to form the concave shape and to further promote the plating condition.
That is, by increasing the current density, the deposition of the plating film is likely to be mottled. In particular, it is difficult for a sufficient current to flow in the concave portion 8, so that the plating film is less likely to be deposited. Although the degree to which the current density is increased is related to the size of the concave portion, the concave portion of the present embodiment has a current density of 4 to 12 / dm ² , more preferably 6 to 10 A / dm, compared to a normal current density of ² to 8 A / dm ^2.
Preferably it is ² .

As another plating condition, it is also effective to lower the pH of the plating solution. The reason for lowering the pH of the plating solution is the same as that for increasing the current density described above. In the present embodiment, it is usually preferable to change the plating solution having a pH of 4.5 to 5.5 to a pH of 4.2 to 4.8.

As another condition, it is preferable to shorten the plating time and reduce the thickness of the plating film. However, this plating film is for preventing a metal member other than the sealing portion from being oxidized and corroded later, and the projection c other than the sealing portion needs to have a coating thickness capable of preventing oxidation.

For example, the plating film of the projection c is 0.7 to 1.0 μm.
m is necessary, and the plating conditions are set so that the thickness of the plating film at the concave portion b at that time is a very thin film of 0 to 0.2 μm.

After that, as shown in FIG. 1B, the low-melting glass 2 and the glass plate 3 are arranged in the concave portion of the metal member 1. As the low-melting glass 2, for example, a PbO-based glass calcined in a ring shape is used.
For example, borosilicate glass or the like is used.

Next, the metal member 1 in which the low melting point glass 2 and the glass plate 3 are arranged in the concave portion is inserted into a jig 4 whose convex portion is made of carbon or alumina as shown in FIG. With a small amount of oxygen in the open state,
For example, the heat treatment is performed in an inert gas atmosphere such as nitrogen gas.

In the heating, the temperature is raised to 500 to 600 ° C. over 10 to 20 minutes, and the temperature is maintained for 10 to 30 minutes to melt. As the temperature raising condition, the temperature is raised for 10 to 20 minutes until the temperature is reached, an oxide film is formed on the sealing portion of the metal member before the glass is melted, and the glass is sealed. This is to make it easier.

A small amount of oxygen mixed in the nitrogen atmosphere forms an oxide film in the sealing portion, but prevents the oxide film from being formed in other portions. Not too small The concentration of oxygen to be mixed is preferably 5 ppm or less, and more preferably 1 pp.
m is preferable. That is, since the concave portion is formed in the sealing portion as described above and the plating is mottled,
The portion where the plating film is not applied is oxidized by a small amount of oxygen, while the portion where the plating film is sufficiently formed is not oxidized in a slight oxygen atmosphere. This small amount of oxygen enters from the space between the inner wall 1e of the metal member 1 formed with the concave portion 6 and the outer periphery of the glass plate 3 and oxidizes the sealed portion. Further, since the protruding portion c is in contact with the carbon jig 4, it does not directly come into contact with oxygen. Even if oxygen invades, it reacts with carbon to become CO ₂ and does not oxidize.

As described above, an oxide film is selectively formed on the portion where the plating film, which is the contact portion of the low melting point glass, is mottled. At this time, the low melting point glass softens and melts, The member 1 and the glass plate 3 are welded through the low-melting glass 2.

In the above embodiment, an example of forming a laser cap will be described, and a Kovar material is used as a metal member. However, for example, 42 alloy, iron, or the like can be used. Applicable to

The formation of the plating film is not limited to the electrolytic nickel plating, but may be plating of chromium, copper, or the like by another electrolytic plating method.

Further, as the atmosphere gas at the time of heating and melting, argon and the like can be used in addition to nitrogen.

Next, a method of sealing metal members with each other will be described. FIG. 2 shows a process diagram in which a first metal member 5 made of iron and a second metal member 6 made of a 42 alloy are sealed with a low melting point glass 2 as a stem member used for a laser diode.

First, as shown in FIG.
The concave portion 9 is formed in the sealing portion of the metal member, and the concave portion 10 is also formed in the sealing portion of the second metal member 6. These recesses 9 and 10
The formation of is intended to make it difficult for the plating film to adhere similarly to the above-described embodiment.

Next, when plating is performed on the first metal member 5 and the second metal member 6 under the same conditions as in the case of the above-described embodiment, the plating films are sufficiently formed in the concave portions 9 and 10. Without being deposited, a sufficient plating film is formed in other portions.

Next, as shown in FIG. 2B, the metal member is assembled with the low-melting glass 2 interposed therebetween, and a jig 7 made of carbon or alumina as shown in FIG. Inside. After that, by performing the melting process in the same atmosphere and temperature as in the above-described embodiment, the sealing between the metal members is completed.

The sealing of the metal members described above has been described using the example of the stem. However, the present invention is not limited to this example, and a concave portion can be formed in a metal member such as another module package. It can be applied to what can be welded through. Therefore, the material of the metal member can be applied to copper, 42 alloy, and the like in addition to iron.

[0034]

According to the method for sealing a metal member of the present invention,
In any of the method for sealing the metal member and the glass plate and the method for sealing the metal member and the metal member, after plating, formation and sealing of the metal oxide film can be performed simultaneously,
There is no need for expensive equipment for pre-oxidation, and the manufacturing process can be simplified. In addition, after sealing, no treatment such as removal of an oxide film is required, and there is no reduction in yield due to glass corrosion during the treatment, deterioration in sealing performance, dirt remaining after washing, etc., and a significant cost reduction can be achieved. it can. Further, since no acid treatment is performed after the sealing, a low-melting glass or a glass plate whose corrosion resistance is not so problematic can be used, which contributes to cost reduction.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a manufacturing process of an embodiment of a method for sealing a metal member and a glass plate.

FIG. 2 is a cross-sectional view illustrating a manufacturing process of one embodiment of a method for sealing a metal member and a metal member.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 metal member 2 low melting point glass 3 glass plate 4 jig 5 first metal member 6 second metal member 7 jig 8 recess 9, 10 recess

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-57-140341 (JP, A) JP-A-63-89438 (JP, A) JP-A-59-141179 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) C03C 27/00-29/00 H01L 23/02 H01R 9/16 101

Claims (2)

(57) [Claims] 1. A method of sealing a metal member to seal a metal member and a glass plate with low melting point glass, wherein a recess is formed in a sealing portion of the metal member, and the metal having the recess is formed. A method for sealing a metal member, comprising plating a member, placing a low-melting glass and a glass plate in this concave portion in this order, and welding them in an inert gas atmosphere containing a small amount of oxygen. 2. A method for sealing metal members, wherein the metal members are sealed with a low-melting glass, wherein a recess is formed in each of the sealing portions of the two metal members, and then the metal members are plated. A method for sealing metal members, comprising joining the two metal members to each other through a low-melting glass and welding them in an inert gas atmosphere containing a small amount of oxygen.