JP3158110B2 - Electronic device manufacturing 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 an electronic component such as a piezoelectric vibrator or a semiconductor element in a container formed of an insulating base such as ceramics and a metal cover in an airtight manner. Things.

[0002]

2. Description of the Related Art Electronic components such as a piezoelectric vibrator and a semiconductor element are hermetically sealed in a container for accommodating the electronic components, thereby forming an electronic device as a product.

[0003] Among such electronic devices, the most reliable one is an insulating base made of ceramics such as an aluminum oxide sintered body and having a mounting portion in the center of the upper surface on which electronic components are mounted. A metal frame made of an iron-nickel alloy or an iron-nickel-cobalt alloy attached to the upper surface of the insulating base so as to surround the mounting portion; an iron-nickel alloy joined to the metal frame by seam welding; This is a type in which electronic components are hermetically sealed in a container made of a metal lid made of an iron-nickel-cobalt alloy.

In the case of this type of electronic device, an electronic component is mounted on a mounting portion of the insulating base, and a metal lid is mounted on a metal frame attached to the insulating base, and the metal cover is mounted on the metal frame. Rolled while contacting a pair of roller electrodes of a seam welding machine with the outer peripheral edge of the lid, and a large current for welding is passed between these roller electrodes to seam weld the metal lid to the metal frame. You.

[0005] In the electronic device of the type described above, the metal frame attached to the insulating base is provided with a frame-shaped metallized metal layer on the upper surface of the insulating base so as to surround the mounting portion. After a nickel plating layer is deposited on the metallized metal layer, the nickel plating layer is attached to the deposited metallized metal layer by brazing a metal frame through a brazing material such as silver brazing. .

However, this type of electronic device is
After the electronic component is mounted on the mounting portion of the insulating substrate, when the metal lid is seam-welded to the metal frame attached to the insulating substrate, the moving speed of the roller electrode of the seam welding machine is at most 3 mm.
Per second, so that it takes a long time of several seconds to seam weld a metal cover of, for example, 3 mm square to a metal frame brazed to an insulating base, and there is a problem of low productivity. .

Further, a metal frame is required as a base metal for seam welding the metal lid to the insulating base, and the height of the electronic device is increased by the amount of the metal frame and it is expensive. There was also a problem that would be.

Accordingly, a mounting portion for mounting an electronic component is provided at the center of the upper surface and an aluminum oxide sintered body having a metallized metal layer having a thickness of about 10 to 20 μm surrounding the mounting portion at the outer peripheral portion of the upper surface. Prepare a container comprising an insulating base made of ceramics and a metal lid made of iron-nickel alloy or iron-nickel-cobalt alloy,
After mounting the electronic component on the mounting portion of the insulating base, the metal lid is electron-beam-welded to the metallized metal layer of the insulating base via a brazing filler metal, so that the inside of the container consisting of the insulating base and the metal lid is formed. Electronic devices in which electronic components are hermetically sealed have been proposed.

An electronic device of a type in which electronic components are hermetically sealed inside a container in which a metal lid is joined to a metallized metal layer of the insulating base by an electron beam welding with a brazing material therebetween is used as the insulating base. Nickel plating is applied to the metallized metal layer to a thickness of 2 to 5 μm, and a metal lid is placed on the metallized metal layer to which the nickel plating is applied with a brazing material interposed therebetween. The electron beam is continuously irradiated on the upper surface of the metal lid while moving at least one round along the frame-shaped metallized metal layer by a magnetic field, and the heat energy of the irradiated electron beam corresponds to the portion irradiated with the electron beam. The metal lid and the insulating base are joined by melting the brazing material.

According to an electronic device of the type in which electronic components are hermetically sealed inside a container in which a metal lid is joined to the metallized metal layer of the insulating base by a beam brazing material via an electron beam welding, the electron beam is sealed. Since the irradiation is performed while moving by the magnetic field, the metal cover can be moved at a high speed of about 300 mm / sec or more. The layers can be welded, which results in extremely high productivity. Further, since a metal frame is not required as a base metal for welding, the height can be reduced accordingly and the cost is low.

[0011]

However, according to such an electronic device, when an electron beam is welded between a metal cover and a metallized metal layer of an insulating substrate via a brazing material, heat generated by the electron beam is used. A large amount of gas contained in the brazing material is released into the container, and this gas remains in the container and adversely affects the normal operation of the electronic components housed in the container. Had.

The present invention has been devised in view of such a conventional problem, and has as its object to perform electron beam welding between a metal cover and a metallized metal layer of an insulating base via a brazing material between the metal cover and the metallized metal layer. It is an object of the present invention to provide a method of manufacturing an electronic device that does not cause a large amount of unnecessary gas to remain inside a container and can normally operate electronic components housed inside the container.

[0013]

According to a method of manufacturing an electronic device of the present invention, an electronic component is mounted inside a frame-shaped metallized metal layer adhered on an insulating substrate, and then, the electronic component is mounted on the metallized metal layer. Placing a metal lid across the material, intermittently irradiating the metal lid with an electron beam moving along the metallized metal layer to melt the brazing material, Forming a mark by irradiating an electron beam on an upper surface of the metal cover, providing a discontinuous portion between the metal cover and the metal cover, Exhausting the inside of the body, irradiating the metal cover with an electron beam along the discontinuous portion to melt the brazing material, eliminating the discontinuous portion, removing the metallized metal layer and the metal cover And before Is characterized in that sequentially carried out and bonding with the brazing material.

According to the method of manufacturing an electronic device of the present invention, the joining of the metallized metal layer and the metal cover by the irradiation of the electron beam is performed by first forming a discontinuous portion on a part of the entire circumference of the metal cover. It is performed by intermittently irradiating the electron beam along the metallized metal layer in such a manner that the mark is formed by irradiating the upper surface of the metal lid with the electron beam, and then from the discontinuity. After exhausting the gas inside the metal lid, the metal lid is irradiated with an electron beam along the discontinuous part to eliminate the discontinuous part and join the metallized metal layer and the metal lid with a brazing material,
Most of the gas generated from the brazing material melted by the heat of the electron beam is exhausted from the discontinuous part. Very little gas evolved remains. Furthermore, when the upper surface of the metal lid is irradiated with an electron beam to form a marker on the surface of the metal lid, the metal lid is bonded and fixed to the metallized metal layer over substantially the entire circumference thereof. Deformation such as warpage of the metal lid is hardly caused by the heat of the electron beam applied to form the mark, and gas generated from the brazing material by the heat of the electron beam applied to form the mark is not affected. Since it is discharged from the continuous portion, there is no adverse effect on the electronic components inside the container.

[0015]

Next, the present invention will be described with reference to the accompanying drawings.

FIG. 2 is a sectional view showing an example of an embodiment of an electronic device obtained by the method of manufacturing an electronic device according to the present invention, wherein 1 is an electronic component, 2 is an insulating base, and 3 is a metal cover. is there. Then, an electronic component 1 such as a piezoelectric vibrator or a semiconductor element is placed inside a container including the insulating base 2 and the metal lid 3.
Is hermetically sealed to constitute an electronic device.

The electronic component 1 is, for example, a piezoelectric vibrator or a semiconductor element, and has a plurality of electrodes (not shown) on its lower surface.

The insulating base 2 is a support for supporting the electronic component 1, and is made of, for example, a ceramic such as a sintered body of aluminum oxide or a sintered body of aluminum nitride. To form a concave portion A. A mounting portion 2a for mounting the electronic component 1 is formed on the bottom surface of the concave portion A, and the electronic component 1 is mounted on the mounting portion 2a.

Further, a metallized wiring layer 4 made of metal powder of metal such as tungsten or molybdenum, which extends from the upper surface of the mounting portion 2a to the lower surface of the insulating substrate 2, is formed on the insulating substrate 2.

The metallized wiring layer 4 functions as a conductive path for electrically leading each electrode of the electronic component 1 to the outside.
Electrodes of the electronic component 1 are electrically connected to a portion on the upper surface of the mounting portion 2a via, for example, a conductive adhesive. The portion of the metallized wiring layer 4 extending to the lower surface of the insulating base 2 is electrically connected to a wiring conductor of an external electric circuit board (not shown) via, for example, solder.

Further, a frame-shaped metallized metal layer 5 made of metal powder such as tungsten or molybdenum and having a width of about 0.4 mm is coated on the outer peripheral portion of the upper surface of the insulating base 2 so as to surround the mounting portion 2a. It is formed.
In this metallized metal layer 5, a metal cover 3 is interposed with brazing material 6 therebetween.
Through electron beam welding.

The metal lid 3 joined to the metallized metal layer 5 of the insulating substrate 2 by means of electron beam welding via a brazing material 6 is made of, for example, an iron-nickel alloy or an iron-nickel-cobalt alloy. It is joined to the metallized metal layer 5 of the insulating substrate 2 by electron beam welding via the brazing material 6 to form a container with the insulating substrate 2 and hermetically seal the electronic component 1 inside the container. are doing.

The brazing material 6 disposed between the metal cover 3 and the metallized metal layer 5 is made of a silver-copper alloy or a lead-tin alloy.
It is made of a gold-tin alloy, aluminum-silicon alloy, copper-zinc alloy, silver-copper-phosphorus alloy, silver-indium-tin alloy, or the like, and functions as a bonding material for bonding the metal cover 3 to the metallized metal layer 5.

Next, in the above-described electronic device, the insulating substrate 2
FIGS. 1A to 1D show an example of an embodiment of manufacturing an electronic device of the present invention in which an electronic component 1 is hermetically sealed in a container formed of a metal cover 3 and a metal cover 3. Description will be given based on a perspective view.

First, as shown in a perspective view in FIG.
An electronic component 1, an insulating base 2, and a metal lid 3 are prepared.

The electronic component 1 is, for example, a piezoelectric vibrator or a semiconductor element, and has a plurality of electrodes (not shown) on its lower surface.

As described above, the insulating base 2 has a mounting portion 2a on which the electronic component 1 is mounted, and a frame-shaped metallized metal layer 5 is provided so as to surround the mounting portion 2a. Is being worn.

If the insulating substrate 2 is made of, for example, an aluminum oxide sintered body, a suitable organic binder and a solvent are added to and mixed with aluminum oxide and raw material powders such as silicon oxide, magnesium oxide and calcium oxide. A plurality of ceramic green sheets are obtained by forming the ceramic slurry in the form of a slurry into a sheet by employing a conventionally known doctor blade method or calendar roll method, and these are appropriately punched, and thereafter, A metal paste for forming the metallized wiring conductor 4 and the metallized metal layer 5 is printed and applied on these ceramic green sheets in a predetermined pattern, and is laminated on the upper and lower sides. Produced by

The metal paste for forming the metallized wiring conductor 4 and the metallized metal layer 5 is obtained by adding an appropriate organic binder and a solvent to a metal powder such as tungsten, for example, and adopts a conventionally known screen printing method. By doing so, the ceramic green sheet is printed and applied in a predetermined pattern.

The metallized wiring layer 4 and the metallized metal layer 5 adhered to the insulating substrate 2 are plated with a metal having excellent corrosion resistance such as nickel or gold and excellent wettability with solder on the exposed surface. If the metallized wiring layer 4 and the metallized metal layer 5 can be effectively prevented from being oxidized and corroded, the metallized wiring layer 4 and the electrodes of the electronic component 1 and the external electric circuit can be effectively prevented. The connection with the wiring conductor of the substrate and the joining by the electron beam welding between the metallized metal layer 5 and the metal lid 3 via the brazing material 6 can be made strong. Therefore, on the surfaces of the metallized wiring layer 4 and the metallized metal layer 5, a metal having excellent corrosion resistance, such as nickel or gold, and having excellent wettability with solder or the like is formed by plating to a thickness of 1 to 20 μm.
m.

The metal cover 3 is a substantially flat plate made of an iron-nickel alloy, an iron-nickel-cobalt alloy, or the like, and a brazing material 6 is previously applied to the entire lower surface thereof.

The metal cover 3 is provided on the lower surface of a large-area plate-shaped base material made of an iron-nickel alloy, an iron-nickel-cobalt alloy, or the like, with a silver-copper alloy, a gold-tin alloy, a lead-tin alloy, A brazing material made of an aluminum-silicon alloy, a copper-zinc alloy, a silver-copper-phosphorus alloy, a silver-indium-tin alloy, or the like is clad to a predetermined thickness by a conventionally known rolling method, plating method, or the like. The base material on which the brazing material is clad is punched into a predetermined shape by a conventionally known punching method, whereby the brazing material 6 is manufactured so as to have the brazing material 6 on the entire lower surface.

Next, as shown in a perspective view in FIG.
The electronic component 1 is mounted on the mounting portion 2a of the insulating base 2, and the metal cover 3 is mounted on the metallized metal layer 5 of the insulating base 2 with the brazing material 6 interposed therebetween.

In order to mount the electronic component 1 on the mounting portion 2a of the insulating base 2, for example, the electrodes of the electronic component 1 and the wiring conductors 4 of the insulating base 1 are connected via a conductive adhesive such as silver-epoxy resin.
Can be employed.

Next, as shown in a perspective view in FIG. 1C, an electron beam 7 is applied to the upper surface of the metal cover 3 in a vacuum atmosphere, and a distance of 0.05 to 0.5 is applied to a part of the irradiation position P, for example. Irradiation is performed intermittently along the frame-shaped metallized metal layer 5 so that a discontinuous portion G of about mm is formed, and the brazing material 6 at a portion corresponding to the irradiation position P is melted according to the irradiation. As a result, the metal cover 3 and the metallized metal layer 5 are joined by forming a discontinuous portion G with the molten brazing material 6.

At this time, since the brazing material 6 does not melt at a portion where the electron beam corresponding to the discontinuous portion G is not irradiated, the metallized metal layer 5 and the brazing material 6 are not melted at this portion.
A gap is formed between the inside and outside of the container.

In this state, the gas generated from the brazing material 6 by the heat of the electron beam 7 is discharged to the outside of the container, for example, for about 0.1 second to 1 minute.
By leaving the metal lid for a while, the gas inside the metal lid is exhausted into the surrounding vacuum atmosphere through the gap formed at the portion corresponding to the discontinuous portion G.

Finally, as shown in a perspective view in FIG. 1D, a portion corresponding to the discontinuous portion G on the upper surface of the metal lid 3 is irradiated with an electron beam 7, and the discontinuous portion G is soldered. By melting the material 6 and closing the gap, the electronic component 1 is placed inside the container including the insulating base 2 and the metal lid 3.
Is hermetically sealed.

At this time, since the gas generated from another portion of the brazing material 6 has already been discharged to the outside, one of the gases generated from the brazing material 6 at the portion corresponding to the discontinuous portion G is inside the container. Only parts remain, and only a very small amount of gas remains. Therefore, the adverse effect on the electronic component 1 due to the gas remaining inside the container can be reduced to a negligible level, and as a result, an electronic device that can normally operate the electronic component 1 can be provided. .

When electronic components are sealed in accordance with this manufacturing method, a large number of containers are prepared side by side in a vacuum atmosphere, and the irradiation positions P are applied to the respective metal lids 3 of the large number of containers. Are successively irradiated with the electron beam 7 so that the discontinuous portions G are formed, and then, the discontinuous portions G of the metal lids 3 of these containers are successively irradiated with the electron beam 7 in the same order. By doing so, it is possible to efficiently provide time for discharging the gas inside the container between the first irradiation and the second irradiation of the electron beam 7 to the same container.

Thus, according to the method of manufacturing an electronic device of the present invention, the amount of gas remaining inside the container composed of the insulating base 2 and the metal lid 3 is extremely small, and the adverse effect of the gas is extremely small. An electronic device that can normally operate the electronic component 1 housed inside the container can be obtained.

The present invention is not limited to the above-described embodiment, and it goes without saying that various changes can be made without departing from the scope of the present invention.

For example, as shown in a perspective view in FIG. 3A, an electron beam 7a is applied to the upper surface of the metal cover 3 so that a discontinuous portion G is formed at a part of the irradiation position P, for example. The metal cover 3 and the metallized metal layer 5 are intermittently irradiated along the frame-shaped metallized metal layer 5 to melt the brazing material 6 at the position corresponding to the irradiation position P.
Are joined by providing a discontinuous portion G with a molten brazing material 6, and an electron beam 7 is provided at the center of the upper surface of the metal lid 3.
To form a mark M for indicating the manufacturer, product name, product number, etc. on the surface of the metal lid 3 and then exhaust the gas inside the container by exhausting the inside of the metal lid 3 , FIG.
As shown in a perspective view in (b), the discontinuous portion G may be irradiated with an electron beam 7 to hermetically seal the container.

In this case, when the mark 7 is formed on the surface of the metal cover 3 by irradiating the center of the upper surface of the metal cover 3 with the electron beam 7, the metal cover 3 is attached to the metallized metal layer 5.
Are fixed by bonding over substantially the entire circumference thereof, so that the electron beam 7 irradiated to form the mark M is formed.
The deformation of the metal lid 3 such as warpage hardly occurs due to the heat of the metal lid 3. Further, gas generated from the brazing material 6 due to the heat of the electron beam 7 irradiated to form the marker M is discharged from the discontinuous portion G before the container is hermetically sealed. There is no adverse effect on the electronic component 1.

The position at which the discontinuous portion G is provided is not limited to one position as shown in FIG. 1 or FIG. 3, but may be provided at several positions as needed by intermittently irradiating an electron beam. Needless to say.

[0046]

According to the electronic device manufacturing method of the present invention,
The joining of the metallized metal layer and the metal lid by the irradiation of the electron beam is performed by forming an electron beam along the metallized metal layer such that a discontinuous portion is formed at a desired portion of the entire circumference of the metal lid. Irradiation is performed intermittently, then the upper surface of the metal lid is irradiated with an electron beam to form a marker, and then the gas inside the metal lid is evacuated from the discontinuous portion, and then the discontinuous portion is formed. Irradiating the metal lid with an electron beam along to eliminate the discontinuity and join the metallized metal layer and the metal lid with the brazing material, the gas generated from the brazing material melted by the heat of the electron beam is Since most of the gas is exhausted from the discontinuous part, only a very small amount of gas generated from the brazing material at the part corresponding to the discontinuous part to be sealed last remains inside the metal lid. No. Furthermore, when the upper surface of the metal lid is irradiated with an electron beam to form a marker on the surface of the metal lid, the metal lid is bonded and fixed to the metallized metal layer over substantially the entire circumference thereof. Deformation such as warpage of the metal lid is hardly caused by the heat of the electron beam applied to form the mark, and gas generated from the brazing material by the heat of the electron beam applied to form the mark is not affected. Since it is discharged from the continuous portion, there is no adverse effect on the electronic components inside the container.

Therefore, a large amount of unnecessary gas does not remain inside the container, and the adverse effect on the electronic components due to the residual gas can be reduced to a negligible level. As a result, the electronic components operate normally. An electronic device capable of performing the above can be provided.

[Brief description of the drawings]

FIGS. 1A to 1D are perspective views for each step for explaining an example of an embodiment of a method of manufacturing an electronic device according to the present invention.

FIG. 2 is a sectional view showing an example of an embodiment of an electronic device manufactured by the manufacturing method of the present invention.

3A and 3B are perspective views for explaining another example of the embodiment of the method of manufacturing an electronic device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electronic component 2 ... Insulating base 2a ... Mounting part 3 ... Metal cover 5 ... Metallized metal layer 6 ... Brazing material 7 ····· Electron beam P ····· Irradiation position of electron beam 7 G ···· Discontinuous part formed at irradiation position P

Claims (1)

(57) [Claims] An electronic component is mounted inside a frame-shaped metallized metal layer attached on an insulating substrate, and then a metal lid is placed on the metallized metal layer with a brazing material interposed therebetween. The metal beam is intermittently irradiated while moving the electron beam along the metallized metal layer to melt the brazing material, and the metallized metal layer and the metal lid are provided with a discontinuous portion to provide a discontinuous portion. Joining with a brazing material, and irradiating the upper surface of the metal lid with an electron beam to obtain a target.
Forming a sense, exhausting the inside of the metal lid from the discontinuous portion, and irradiating the metal lid with an electron beam along the discontinuous portion to melt the brazing material, A step of joining the metallized metal layer and the metal lid with the brazing material in order to eliminate the discontinuous portion.