JP2685883B2 - Method for forming encapsulating metallization layer in ceramic package - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is to solder a lid made of ceramics or glass to a package made of ceramics or glass in which LSIs, ICs, sensors, devices (elements), etc. are mounted. The present invention relates to a method of forming a sealing metallization layer on a package and a lid in order to improve wettability with solder when sealing.

(Prior Art) Conventionally, as shown in FIG. 7, a package 2 made of ceramics (or glass) in which a component 1 such as an LSI, an IC, a sensor, and a device (element) is mounted in a ceramic substrate in a vacuum or an inert gas atmosphere. When sealing with the lid 3 (or glass substrate), solder that releases less gas is used as a sealing material.

However, since solder has poor wettability with ceramics and glass, various measures have been taken.

For example, as shown in FIG. 8a, a Cr film 4 is formed on the lid 3 of the ceramic substrate (or glass substrate) by vapor deposition or sputtering.
And Au film 5 are formed, a resist is applied to this and dried, a pattern is printed by alignment, developed, etched, and resist is peeled off to achieve the required sealing as shown in FIG. 8b. The metallized layer 6 is formed, and the lid 3 having the metallized layer 6 for sealing is attached to the upper edge of the peripheral wall as shown in FIG.
A film 5'is formed and soldered in a vacuum or an inert gas atmosphere to a package 2 made of ceramics (or glass) in which a component 1 having a frame-shaped solder plate 7 punched thereon is mounted. The package 2 was sealed. In some cases, molten solder may be applied on the Au film 5'instead of the frame-shaped solder plate 7.

(Problems to be Solved by the Invention) However, according to the above-mentioned method for sealing the ceramic package, the Cr film 4 is provided on the lid 3 of the ceramic substrate or the glass substrate.
A lot of man-hours are required to form the sealing pattern 6 for the Au film 5, and similarly, to form the Cr film 4'and the Au film 5'on the upper edge of the peripheral wall of the package 2 made of ceramics or glass. However, a lot of man-hours are required, and therefore, preparation of package encapsulation requires a lot of time and cost, productivity of encapsulation products is poor, and cost is high.

In view of the above, the present invention provides a sealing metallization for improving the wettability of solder to the mutual sealing joint surface between the package of ceramics or glass and the lid so that preparation for package sealing does not take much time and cost. An object of the present invention is to provide a method capable of forming a layer easily with a small number of steps and efficiently.

(Means for Solving the Problems) One of the methods for forming the sealing metallization layer in the ceramic package of the present invention for solving the above problems is to seal the package and the lid made of ceramics or glass with each other. One of water platinum, water gold, and water silver is applied and printed on the joint surface by a screen printing method, and dried and baked to form a metal film.

Another method of forming a sealing metallization layer in a ceramics package of the present invention is that a package and a lid made of ceramics or glass are bonded to each other at a sealing joint surface.
It is characterized in that water platinum is applied and printed by the screen printing method, dried and baked to form a platinum film, and then water gold is applied and printed by the screen printing method and dried and baked to form a gold film. It is what

Still another method of forming the sealing metallization layer in the ceramic package of the present invention is to mix water platinum and water gold on the mutual sealing joint surface of the package and the lid made of ceramics or glass by a screen printing method. It is characterized in that a platinum-gold alloy film is formed by coating and printing a liquid, drying and baking.

(Operation) As described above, in the method for forming the sealing metallization layer of the present invention, the sealing metallization layer is formed on the mutual sealing joint surface between the ceramic or glass package and the lid.
Since the number of steps such as screen printing, drying and baking is small, it is efficient and easy.

(Embodiment) An embodiment of a method for forming a sealing metallization layer in a ceramic package of the present invention will be described with reference to the drawings. As shown in FIG. 1a, an alumina substrate having a length of 5 mm, a width of 10 mm, and a thickness of 1 mm is formed. On the sealing joint surface 3a having a width of 1 mm around the lid 3, water platinum is applied and printed by a screen printing method using a screen having a predetermined pattern, dried and sintered to form a 1 μm film as shown in FIG. 1b. A platinum film 10 is formed, and water gold is applied and dried on the platinum film 10 by a screen printing method using a screen having a predetermined pattern as well. After drying, the gold film 11 having a thickness of 1 μm is formed as shown in FIG. 1c. After formation, a metallizing layer 12 for sealing was obtained. Similarly, as shown in FIG. 2a, a screen having a predetermined pattern is used for the sealing joint surface 2a, which is the upper edge of the peripheral wall of the package 2 made of alumina and having a length of 5 mm, a width of 10 mm, a height of 4 mm, and a wall thickness of 1 mm. Water platinum is applied and printed by a screen printing method, dried and sintered to form a platinum film 10 having a thickness of 1 μm as shown in FIG. 2b, and a screen having a predetermined pattern is also used on the platinum film 10 to perform a screen printing method. Water gold was applied and dried, and after drying, it was sintered to form a 1 μm gold film 11 as shown in FIG. 2c to obtain a metallizing layer 12 for sealing.

In this way, the lid 3 of the alumina substrate provided with the encapsulating metallization layer 12 and the package 2 made of alumina have the components 1 such as LSI, IC, sensor, device (element) mounted in the package 2 as shown in FIG. Then, the solder plate 7 was interposed between the sealing metallization layers 12 in a vacuum or an inert gas atmosphere, and soldering was performed for sealing.

Next, another embodiment will be described. As shown in FIG. 4a, a predetermined pattern is formed on a sealing bonding surface 3a having a width of 1 mm around a lid 3 of a glass substrate having a length of 10 mm, a width of 20 mm and a thickness of 1 mm. A screen-printing method is used to coat and print a mixed solution of water platinum and water gold on the screen, and after drying and sintering, a platinum-gold alloy film 13 of 1 μm is formed as shown in FIG. Layer 14 was obtained. Similarly, as shown in FIG. 5a, a package 2 made of glass, 10 mm long, 20 mm wide, 9 mm high, and 1 mm thick.
On the sealing joint surface 2a, which is the upper edge of the peripheral edge, a mixture of water platinum and water gold is applied and printed by a screen printing method using a screen having a predetermined pattern, and after drying, sintering is performed, as shown in FIG. 5b. As shown, a 1 μm platinum-gold alloy film 13 was formed to obtain a sealing metallization layer 14.

In this way, the lid 3 of the glass substrate provided with the sealing metallization layer 14 and the package 2 made of glass are mounted with components 1 such as LSIs, ICs, sensors, devices (elements) in the package 2 as shown in FIG. After that, the molten solder is interposed between the sealing metallization layers 14 in a vacuum or an inert gas atmosphere,
Soldered and sealed.

Although water platinum and water gold were used to form the metallized layer in the above-mentioned examples, the present invention is not limited to this, and any one of water platinum, water gold, and water silver is used alone. You can do it.

(Effects of the Invention) As can be seen from the above description, in the method for forming the sealing metallization layer of the present invention, the sealing metallization layer is formed on the mutual sealing joint surfaces of the ceramic or glass package and the lid. However, the number of man-hours required for screen printing, drying, and baking is small, so that it is efficient and simple. Therefore, it is possible to save a lot of time and cost required for preparation for package encapsulation, improve the productivity of the encapsulation product, and reduce the cost.

[Brief description of the drawings]

1A, 1B, 1C show steps of applying one of the methods for forming a sealing metallization layer of the present invention to a lid of an alumina substrate, and FIGS. 2A, 2B and 2C show a package made of alumina. The figure which shows the process which applied one of the formation methods of the metallization layer for sealing of this invention, FIG. 3 is a cross section which shows the state which sealed the lid of FIG. 1c by the package of FIG. 2c by soldering. Figure,
FIGS. 4a and 4b are diagrams showing steps of applying another one of the methods for forming a metallizing layer for sealing of the present invention to a lid of a glass substrate,
5a and 5b are diagrams showing a process in which another method of forming the metallizing layer for sealing of the present invention is applied to a package made of glass, and FIG. 6 shows the lid of FIG. 4b. FIG. 7 is a cross-sectional view showing a state in which the package b is sealed by soldering, FIG. 7 is a diagram showing a conventional ceramic package sealing method,
8A and 8B are diagrams showing a process in which a conventional method for forming a metallizing layer for sealing is applied to a lid of a ceramic substrate, and FIG. 9 shows a metallizing layer for sealing similarly formed on the lid of the ceramic substrate. It is sectional drawing which shows the state which was soldered and sealed to a ceramics package.

Claims (3)

(57) [Claims] 1. A package and a lid made of ceramics or glass are coated and printed by a screen-printing method with any one of water platinum, water gold, and water silver on a mutual sealing joint surface, and dried and baked. A method for forming a sealing metallization layer in a ceramic package, which comprises forming a metal film. 2. A package made of ceramics or glass and a lid, which are sealed with each other, are coated and printed with water platinum by a screen printing method, dried and baked to form a platinum film, and the screen printing is also performed thereon. A method of forming a metallization layer for encapsulation in a ceramics package, which comprises applying and printing water gold by a method, followed by drying and baking to form a gold film. 3. A platinum-gold alloy film is formed by coating and printing a mixed liquid of water platinum and water gold on a mutual sealing joint surface of a package and a lid made of ceramics or glass by a screen printing method and drying and baking. A method for forming a metallizing layer for encapsulation in a ceramic package, which is characterized by being formed.