JPS5976689A - Airtight sealing method of aluminum package - Google Patents

Abstract

PURPOSE:To obtain a weld zone having high airtightness without generation of any weld crack by performing preheating and afterheating in the weld zone by a continuously oscillated laser having a low output, and performing regular welding by using said laser in conjunction with a pulse laser having a large output. CONSTITUTION:The laser beam 9 from a laser system 8 which oscillates continuously the laser having a low output is condensed by a half mirror 7 and a lens system 5. The condensed laser is irradiated to the weld zone 6 of a package consisting of a case 1 and a cover 2, whereby the weld zone is subjected to preheating and afterheating. On the other hand, the laser beam 10 from a laser system 34 which oscillates a pulse laser having a large output is irradiated likewise to the weld zone 6 whereby regular welding is performed. The case for generating the weld crack in the aluminum package is thus eliminated and the stable airtight welding is accomplished. This method is used for airtight sealing of the package of a GaAs semiconductor module for microwave, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Branch Field of the Invention The present invention relates to hermetic sealing of packages such as micro-liquid uaAe semiconductor modules, and in particular to hermetic sealing of packages such as micro-liquid uaAe semiconductor modules. Concerning the method of ceasing publication.

(2) Background of the Japanese Literature Conventional packages are mainly made of iron-based materials, mainly stainless steel, but they suffer from poor heat conduction. For this reason, there is a strong demand for an aluminum package that is lightweight and has good thermal conductivity to withstand the heat generation that accompanies the increased output of amplifiers in recent years and demands for lighter weight amplifiers.

(3) Prior art and problems The most important point when using Cf as an aluminum or nickel-gold package is the hermetic sealing method. In other words, since the semi-integrated circuit board (il-JIi) is mounted, exposing the whole bar to high temperatures such as in a wax tank will cause deterioration of the element and cannot be adopted. However, because the sled power was too low and aluminum's heat dissipation was too strong, the molten coal turned into a waste and eventually became an electron beam.

A welding method that can locally apply large amounts of power using Rede is used.

Figure 1 shows an aluminum computer case A box consisting of case 1 and cover 2. These shrines A are made of an alloy of pure aluminum and have no particular problems as merepo containers.

However, in welding where the thickness is locally increased by -4, the cooling rate of the bath welding part is extremely fast, so cracks mainly occur in the bath weld bead, and sufficient airtightness cannot be maintained. is the current situation.

Figure 2 shows a schematic diagram of a 6-bath vessel using a conventional high-output pulse laser. A laser beam from a high-output laser 4 is focused on a welding gap 6 of the package A by a gold lens system 5, and melts at the corresponding location.

In this case, when the high-output laser 4 is cut, the above-mentioned twisted rack exists, and sufficient airtightness cannot be maintained.

(4) Purpose of the Invention The purpose of the present invention is to provide a complete method for airtightly sealing an aluminum package without causing cracks in the welded area using a radar. It is very special.

(5) Structure of the Invention The present invention uses a low-output continuous -#3 laser laser and a Hatake output pulsed laser metal, and performs preheating of 16 points with the low-output laser and "annealing after #3". Yes, the actual welding was accomplished using a high-output pulsed laser.

(6) Implementation sequence of the invention Hereinafter, the invention method will be explained with reference to the drawings.

FIG. 3 shows the hermetic seal welding method according to the present invention.

First, a low-power laser beam 9 from a first generation continuous wave laser 7 and a stem 8 is applied to the bath contact part 6 through a half-mirror 7° lens thread 5.
Turn on the valve and irradiate to preheat.

At two intervals, the human power pulsed laser beam 10 from the high-output Valsleg @Fumi 7 stem 34 is irradiated to the same region. At this time, you can irradiate 9 laser beams and cut it off even if it is dangerous. Book-1! In Kin, low power continuous wave laser 7 stem 8
Laser beam 9 from 100W average output beam 4
The laser beam 10 from the high output pulse laser system 34 is emitted as u 5wa, 4msQ1g, 25P.
Irradiated as p8.380i111. Note that the laser beam 9 remained irradiated even during the irradiation of the high-power pulsed laser beam lOff:jffl.

Under these conditions, the welded parts 6 of the irradiated metal material, the case 1, and the cover 2 were melt-welded. At Konin, we developed the first Yag Laser Kumquat as a low-power continuous laser system.

In addition, a second Yag laser kumquat was used as a high-output pulse laser oscillation system. Incidentally, as a Tani Radhe system, a combination of an argon laser, a carbon dioxide laser, and a glass laser #ff can be used for IIg of Segley ν'. On the arrow, the laser is placed at all ψ positions and low output is continuously @ shake - The Beam 9
By doing this, the welded part was subjected to intense cooling and annealing, so that a welded part with no cracks and no residual strain was formed.

! 1', the width of the welding pitch 11 was 6M, and the penetration depth was 1.0 mm.

When the airtightness of the aluminum package sealed with Am according to the present invention was examined using a helium leak detector, it was confirmed that the package had a high airtightness of 10" 1 Ltln-QC18 or higher, and had no practical problems.

(7) Effects of the invention According to the present invention, the output element can be mounted on the tower (good heat dissipation), and the quality of the aluminum package ((j
The sealing capacity is easily 6J.

[Brief explanation of the drawing]

The phase 1 diagram shows the g of the aluminum package.
Figure 3 shows the welding process using a laser beam.
FIG. 3 is a diagram showing a welding method using a laser. l: case, 2=cover, 3: input/output terminal. 42 high output lasers, 6: lens system, 6: welding part. 7: Herno mirror, 8: Continuous wave laser output.

Claims (3)

[Claims] (1) In a package consisting of an aluminum base alloy case and cover, when the case and cover are hermetically sealed by laser welding, a low-power continuous wave laser is used to
Heat it up and then weld it with an output pulse laser!
Features a hermetic sealing method for aluminum packages. (2) The method for hermetically sealing an aluminum package according to claim 1, wherein the 1°C output continuous wave laser is a YAG laser, an argon laser, or a carbon dioxide laser. (3) The upper St high-power pulse laser is
) A method for sealing an aluminum package according to item 1 of the patent Hfi ice, characterized in that the laser or carbon dioxide laser is used.