JP2003068900A - Package for housing electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that after a metal cover is welded to a metal frame brazed to a sealing metallized layer, the frame might be released from the sealing metallized layer so that the hermetically sealing reliability of a package is low. SOLUTION: A package for housing an electronic component comprises an insulating base 1 having the component 5 mounted on an upper surface thereof, a rectangular frame-like sealing metallized layer 2 having a roundness 10 on an outer periphery of a corner covered so as to surround the mounting part on an upper surface of the base 1, a rectangular frame-like metal frame 3 having a roundness 9 on an outer periphery of a corner connected to the upper surface of the layer 2 via a brazing material, and a cover 4 mounted on an upper surface of the frame 3 in such a manner that a radius of curvature of the roundness 9 of the outer periphery of the corner of the frame 3 is larger than that of the roundness 10 of the outer periphery of the corner of the layer 2. Thus, the frame 3 is rigidly connected to the layer 2 via a brazing material reservoir 8 of a sufficient size at the respective corners.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component storage package for storing electronic components such as semiconductor devices, piezoelectric vibrators, surface acoustic wave devices and the like.

[0002]

2. Description of the Related Art Conventionally, a small electronic component storing package for storing electronic components such as semiconductor elements and piezoelectric vibrators is shown in FIG. 3 in a plan view with a lid removed, and in FIG. 4 as a side view. In order to mount the electronic component 21 in the center of the top surface, it is made of an electrically insulating material such as aluminum oxide sintered body, aluminum nitride sintered body, mullite sintered body, glass ceramics sintered body, etc. Of the insulating base 24 having the concave mounting portion 22 and a plurality of wiring conductors 23 extending from the inside of the mounting portion 22 to the outer periphery of the lower surface, and tungsten deposited on the upper surface of the insulating base 24 so as to surround the mounting portion 22. And a sealing metallization layer 25 in the shape of a substantially rectangular frame made of metal powder metallization such as molybdenum and molybdenum.
A metal frame 26 having a substantially rectangular frame shape and made of a metal such as an iron-nickel-cobalt alloy bonded to the upper part of the mounting portion 22 through a brazing material such as silver-copper brazing, and the metal frame. A metal lid 27 made of a metal such as an iron-nickel-cobalt alloy that is attached to the upper surface of the body 26 by welding such as the seam weld method or by brazing with a brazing material such as gold-tin 27.
It consists of and.

According to this conventional electronic component storing package, the electronic component 21 is provided on the bottom surface of the mounting portion 22 of the insulating substrate 24.
In addition to mounting the
It is electrically connected to the inner wiring conductor 23 via an electrical connecting means composed of, for example, solder or conductive resin / bonding wire, and then the metal lid 27 is attached to the upper surface of the metal frame 26 by the seam weld method or the like. Insulating substrate by attaching by welding or by brazing through a brazing material such as gold-tin
The electronic component 21 is hermetically sealed inside a container made up of 24, the sealing metallization 25, the metal frame 26, and the metal lid 27 to form an electronic device.

The metal frame 26 is manufactured by punching a plate material of iron-nickel-cobalt alloy with a punching die, and usually the outer peripheral corners are rounded.
28 are formed. Further, the radius of curvature of the roundness 28 at the outer circumference of each corner of the metal frame 26 is formed to be substantially the same as the radius of curvature of the roundness 29 at the outer circumference of each corner of the sealing metallization layer 25. There is.

[0005]

By the way, in such a conventional package for storing electronic parts, there has been a rapid downsizing in response to the recent demand for downsizing of electronic devices. Set the width of the stop metallization layer 25 to 0.
The width of the metal frame 26 is narrow as about 0.20 mm to 0.45 mm while the width is about 35 mm to 0.6 mm. Further, the radius of curvature of the roundness 29 at each corner of the outer periphery of the sealing metallized layer 25 and the radius of curvature of the roundness 28 at each corner of the outer periphery of the metal frame 26 are made as small as about 0.2 mm to 0.5 mm.

The metal frame 26 is placed on the upper surface of the sealing metallization layer 25 with a brazing material so that the inner peripheral surface of the metallizing layer 25 for sealing and the inner peripheral surface of the metal frame 26 are aligned with each other. It is joined. At this time, since the width of the sealing metallization layer 25 is wider than the width of the metal frame 26, a region where the metal frame 26 does not overlap is formed on the outer peripheral side of the sealing metallization layer 25, and the metal frame 26 is formed in the region. A brazing filler metal reservoir 30 for joining the outer peripheral surface of the and the surface of the sealing metallization layer 25 is formed.

However, the region on the outer peripheral side of the encapsulating metallization layer 25 in which the brazing filler metal reservoir 30 is formed is rapidly narrowed due to the recent demand for miniaturization of electronic devices. Therefore, it becomes difficult to form a brazing filler metal reservoir 30 having a sufficient size for joining the sealing metallization layer 25 and the metal frame 26, and the brazing filler metal is used for the sealing metallization layer 25 and the metal frame 26. It is difficult to obtain sufficient strength when joining via.

Therefore, according to such an electronic component storing package, after the electronic component 21 is mounted on the mounting portion 22 of the insulating base 24, the metal lid 27 is mounted on the upper surface of the metal frame 26 by the seam weld method or the like. When attached by welding or by brazing via a brazing material such as gold-tin, the metal frame 26 and the metal lid 27, which have undergone large thermal expansion due to the heat during attachment, largely contract in the cooling process after welding. As a result, a large thermal stress is applied to the sealing metallization layer 25 so as to pull it inward. In the miniaturized package as described above, since the width of the sealing metallization layer 25 is narrow, the brazing filler metal reservoir 30 having a sufficient size cannot be formed. The metallization layer 25 for use may peel off. In particular, at each corner located in the diagonal direction, the shrinkage amount of the metal frame body 26 and the metal lid body 27 becomes larger than that of the other parts, so that heat is applied to the outer periphery of the sealing metallization layer 25 at each corner. The stress is largely concentrated, and the tendency that the metal frame 26 and the sealing metallization layer 25 are easily peeled off due to the large concentrated thermal stress becomes remarkable. Therefore, there has been a problem that the airtight reliability of the electronic device using this conventional package for storing electronic components is greatly impaired.

The present invention has been devised in view of the above problems of the prior art, and an object thereof is to weld a metal lid to a metal frame by welding such as the seam weld method or to use gold-tin or the like. The metal frame and the metallizing layer for sealing do not separate even if a thermal stress generated by thermal contraction of the metal frame and the metal lid is applied after the attachment by brazing with a brazing material. , It is to provide a small package for storing electronic components, which is highly airtight and highly reliable.

[0010]

An electronic component storing package of the present invention comprises a substantially rectangular plate-like body, and a mounting portion on which an electronic component is mounted and an electrode of the electronic component near the mounting portion. An insulating base having a wiring conductor to be electrically connected, and a square frame-shaped sealing metallizing layer having a rounded outer periphery of a corner portion attached to the upper surface of the insulating base so as to surround the mounting portion, A rectangular frame-shaped metal frame body having a rounded outer periphery of a corner portion joined to the upper surface of the sealing metallization layer via a brazing material, and the electronic device mounted on the mounting portion on the upper surface of the metal frame body. A lid attached so as to cover the component, the outer periphery of the corner of the metal frame is located inside the outer periphery of the corner of the sealing metallization layer, and the corner of the metal frame is The radius of curvature of the outer periphery of the metallization layer for sealing It is characterized in that it has greater than the radius of curvature of the outer periphery of the rounded corners.

Further, in the electronic component storage package of the present invention having the above-mentioned structure, the radius of curvature of the roundness of the outer periphery of the corner of the metal frame is smaller than the radius of curvature of the outer periphery of the corner of the metallizing layer for sealing. Is also characterized by being larger by 0.05 to 0.50 mm.

According to the package for storing electronic parts of the present invention, the outer periphery of the corner of the metal frame is located inside the outer periphery of the corner of the metallizing layer for sealing, and the outer periphery of the corner of the metal frame is Since the radius of curvature of the roundness is made larger than the radius of curvature of the outer periphery of the corner of the sealing metallization layer, the area where the brazing filler metal is formed is widened on the outer periphery of the corner of the sealing metallization layer. Therefore, it becomes possible to form a brazing filler metal pool having a sufficient size. Therefore, when the metal frame is joined to the metallizing layer for sealing through the brazing filler metal, a brazing filler metal reservoir having a sufficient size is formed,
The bonding strength between the metal frame and the metallizing layer for sealing becomes stronger. Thereby, after the metal lid is attached to the metal frame by welding such as the seam weld method or by brazing with a brazing material such as gold-tin, thermal stress is applied to the outer peripheral corners of the metal frame. However, it is possible to prevent the metal frame body from peeling off from the sealing metallization layer.

[0013]

DETAILED DESCRIPTION OF THE INVENTION The present invention will now be described with reference to the accompanying drawings. FIG. 1 is a plan view showing an example of an embodiment of an electronic component storing package of the present invention with a lid removed, and FIG. 2 is a side view with a lid attached. In these figures, 1 is an insulating substrate, 2 is a metallizing layer for sealing, 3 is a metal frame, and 4 is a metal lid. A container for housing the electronic component 5 in an airtight manner is mainly configured by these.

The insulating substrate 1 has a substantially quadrangular shape having a side length of about 2 to 10 mm and a thickness of about 0.5 to 2 mm, and has a substantially quadrangular concave mounting portion 6 for mounting the electronic component 5 in the center of the upper surface thereof. Is provided. The electronic component 5 is mounted and fixed on the mounting portion 6.

The insulating substrate 1 is made of an electrically insulating material such as an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, a glass ceramic sintered body, and the like. If it is composed of a body, it is made into a sludge by adding and mixing an appropriate organic binder and solvent to raw material powder such as aluminum oxide, silicon oxide, calcium oxide, magnesium oxide, etc. To obtain a plurality of ceramic green sheets by making a sheet shape, and then after performing a predetermined punching process on each of these ceramic green sheets and stacking them on top of each other, a temperature of about 1600 ° C It is manufactured by firing at.

On the insulating base 1, a plurality of wiring conductors 7 extending from the bottom surface of the mounting portion 6 to the lower surface via the side surface of the insulating base 1 are adhered. The wiring conductor 7 is mounted on the mounting portion 6.
Functions as a conductive path for electrically connecting each electrode of the electronic component 5 mounted on the board to an external electric circuit, and each electrode of the electronic component 5 is soldered to a portion located on the bottom surface of the mounting portion 6 thereof. It is electrically connected via an electrical connecting means such as a conductive resin or a bonding wire, and the portion led out to the lower surface of the insulating base 1 is connected to an external electric circuit via an electrical connecting means made of solder or the like. .

The wiring conductor 7 is made of metal powder metallization of tungsten, molybdenum, copper, silver or the like.
A metal paste obtained by adding and mixing a suitable organic binder or solvent to a metal powder such as tungsten is printed and applied in a predetermined pattern on a ceramic green sheet for the insulating substrate 1 by a screen printing method or the like, and this is used for the insulating substrate 1. By being fired together with the ceramic green sheet laminated body of (1), it is adhered and formed so as to extend from the bottom surface of the mounting portion 6 of the insulating base body 1 to the lower surface via the side surface of the insulating base body 1.

On the surface of the wiring conductor 7, the wiring conductor 7
Effectively prevents the metal from being oxidized and corroded and the wiring conductor 7
In order to improve the connectivity between the electrical connection means and the electrical connection means, a nickel plating layer having a thickness of about 1 to 10 μm and a gold plating layer having a thickness of about 0.1 to 3.0 μm are usually used for the well-known electrolysis. It is sequentially deposited by a plating method or an electroless plating method.

Further, on the upper surface of the insulating substrate 1, a metal plate layer 2 for sealing, which is formed of metal powder metallization of tungsten, molybdenum, copper, silver or the like and has a substantially rectangular frame shape, is formed so as to surround the mounting portion 6. ing. The metallizing layer 2 for sealing has a thickness of about 10 to 20 μm and a width of each side of 0.35 to 0.
It has a roundness 10 of about 6 mm and a radius of curvature of 0.2 to 0.5 mm at each corner of its outer periphery, and functions as a base metal for joining the metal frame 3 to the insulating base 1.
A metal frame 3 having a substantially rectangular frame shape surrounding the mounting portion 6 is brazed to the upper surface of the sealing metallization layer 2 through a brazing material such as silver-copper brazing.

When the metal frame 3 is brazed to the sealing metallization layer 2, the concave inner peripheral surface of the mounting portion 6, the inner peripheral surface of the sealing metallizing layer 2 and the inner peripheral surface of the metal frame 3 are brazed. Match the surfaces and join them. As a result, the metal frame body 3 comes to be located at the central portion of the sealing metallization layer 2, and the outer periphery of the corner portion of the metal frame body 3 is located inside the outer periphery of the corner portion of the sealing metallization layer 2. , Metallization layer 2 for sealing
The width of the portion where the brazing material pool is formed is the same at each corner.

The metallizing layer 2 for sealing as described above is prepared by screen-printing a metal paste obtained by adding and mixing an appropriate organic binder or solvent to a metal powder such as tungsten on a ceramic green sheet for the insulating substrate 1. Then, a predetermined pattern is printed and applied, and this is baked together with the ceramic green sheet laminated body for the insulating base 1, so that the mounting portion 6 is attached and formed on the upper surface of the insulating base 1.

The surface of the sealing metallization layer 2 is
In order to improve the wettability between the sealing metallization layer 2 and the brazing material, a nickel plating layer having a thickness of about 0.5 to 5 μm is usually pre-deposited before brazing.

The metal frame 3 brazed to the sealing metallization layer 2 via a brazing material such as silver-copper brazing is made of a metal such as an iron-nickel alloy or an iron-nickel-cobalt alloy. , Functions as a base metal member for attaching the metal lid 4 to the insulating base 1. This metal frame 3 is
The inner peripheral surface is the opening of the recess 6 and the sealing metallization layer 2
It is about the same size as the inner peripheral surface of and has a thickness of 0.1 to 0.25 mm.
The width of each side is about 0.20 to 0.45 mm. And
The radius of curvature of the outer circumference of each corner 9 is 0.05 to 0.50 m than the radius of curvature of the outer circumference of the sealing metallization layer 2.
It is formed as a large m.

The radius of curvature of the roundness 10 at each corner of the outer periphery of the encapsulating metallization layer 2 differs depending on the size of the insulating substrate 1, and normally the insulating substrate 1 has a size of 2 to 3 m.
If it is about m, the radius of curvature of the roundness 10 of the outer periphery of the corner portion of the sealing metallization layer 2 is about 0.2 mm, and the insulating substrate 1
If the size is about 5 to 10 mm, the radius of curvature of the roundness 10 at the outer periphery of the corner portion of the sealing metallization layer 2 is about 0.5 mm. Therefore, if the radius of curvature 10 of the outer circumference of each corner of the metallizing layer 2 for sealing is 0.2 mm, the radius of curvature 9 of the outer circumference of each corner of the metal frame 3 should be 0.25 to 0.70 mm. Good. Also, the roundness of the outer periphery of each corner of the sealing metallization layer 2
When the radius of curvature of 10 is 0.5 mm, the radius of curvature of the roundness 9 on the outer periphery of each corner of the metal frame 3 may be 0.55 to 1.0 mm.

Then, a metal lid 4 is placed on the metal frame 3.
And the metal lid 4 is attached to the metal frame 3 by welding such as the seam weld method or by brazing with a brazing material such as gold-tin.

In the package for storing electronic parts according to the present invention, the radius of curvature of the outer roundness 9 at each corner of the metal frame 3 is smaller than the radius of curvature of the outer roundness 10 at each corner of the sealing metallization layer 2. When the size is also increased by 0.05 to 0.50 mm, the area where the brazing filler metal reservoir 8 is formed in each corner portion is widened without unnecessarily increasing the encapsulation metallization layer 2 and the package is downsized. The brazing material reservoir 8 having a sufficient size can be formed, and the bonding strength between the metal frame body 3 and the sealing metallization layer 2 becomes strong.

Therefore, the metal lid 4 is provided on the upper surface of the metal frame 3.
After being attached by welding such as the seam weld method or by brazing with a brazing material such as gold-tin, the metal frame 3
And even if the thermal stress generated by the thermal contraction of the metal lid 4 is applied to the outer peripheral corners of the sealing metallization layer 2,
It is possible to prevent the metal frame body 3 from peeling from the sealing metallization layer 2. Therefore, according to the electronic component storage package of the present invention, it is possible to obtain an electronic device having excellent airtightness and reliability.

The radius of curvature of the outer roundness 9 at each corner of the metal frame 3 is greater than the radius of curvature of the outer roundness 10 at each corner of the sealing metallization layer 2 by 0.05 mm. If it is less than the above range, it becomes difficult to sufficiently secure the region where the brazing material reservoir 8 is formed on the outer peripheral side of each corner of the sealing metallization layer 2. for that reason,
It is difficult to obtain sufficient bonding strength between the sealing metallization layer 2 and the metal frame 3 at each corner without forming the brazing filler metal reservoir 8 having a sufficient size. Thereby, after the metal lid 4 is attached to the upper surface of the metal frame 3 by welding such as the seam weld method or by brazing with a brazing material such as gold-tin, the metal frame 3 and the metal lid 4 are attached. The metal frame 3 may be peeled off from the sealing metallization layer 2 due to the thermal stress generated by the thermal contraction of the above, and the airtight reliability of the electronic component storage package will be deteriorated.

Further, the radius of curvature of the outer roundness 9 at each corner of the metal frame 3 exceeds the radius of curvature of the outer roundness 10 at each corner of the sealing metallization layer 2 by more than 0.50 mm. In that case, the width of the metal frame body 3 at each corner is narrow. Therefore, the sealing width when the metal frame body 3 and the metal lid body 4 are attached to each other is narrow, so that there is a large risk that the airtightness and reliability of the package is deteriorated.

Therefore, in order to form a brazing filler metal reservoir 8 of a sufficient size on each corner of the sealing metallization layer 2 and to secure a sealing width at each corner of the metal frame body 3, The radius of curvature of the roundness 9 on the outer periphery of each corner of the frame 3 is
It is preferable that the radius of curvature of the roundness 10 on the outer periphery of each corner of the sealing metallization layer 2 is larger by 0.05 to 0.50 mm.

The metal frame 3 as described above is manufactured in a predetermined frame shape by punching a plate material made of an iron-nickel alloy, an iron-nickel-cobalt alloy or the like with a press machine.

The metallization layer 2 for sealing the metal frame 3 is also provided.
Brazing to the metallizing layer for sealing is performed by, for example, placing a foil-shaped brazing material having a thickness of 10 to 50 μm on the sealing metallizing layer 2 and then heating and melting the brazing material. 2 and the metal frame 3 are brazed.

The sealing metallization layer 2 after brazing is used.
The sealing metallization layer 2 and the metal frame 3 are provided on the exposed surface of the metal frame 3 and the exposed surface of the metal frame 3.
In order to effectively prevent the oxidative corrosion of the brazing material, a nickel plating layer having a thickness of 0.5 to 5 μm and a gold plating layer having a thickness of about 0.1 to 3.0 μm are usually provided by a conventionally known electrolytic plating method or It is sequentially deposited by the electrolytic plating method.

Thus, according to the electronic component storage package of the present invention, after the electronic component 5 is mounted and fixed on the mounting portion 6 of the insulating substrate 1, each electrode thereof is connected to the wiring conductor 7 through the electrical connecting means. By attaching the metal lid body 4 to the metal frame body 3 by welding such as the seam weld method or by brazing with a brazing material such as gold-tin, and hermetically sealing the electronic component 5 inside, It is possible to provide an electronic device that is highly airtight and reliable.

It should be noted that the present invention is not limited to the examples of the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

[0036]

According to the package for storing electronic parts of the present invention, the outer periphery of the corner of the metal frame is located inside the outer periphery of the corner of the metallizing layer for sealing, and each corner of the metal frame is located. Since the radius of curvature of the roundness of the outer periphery of the sealing metallization layer is made larger than the radius of curvature of the roundness of the outer periphery of each corner of the metallizing layer for sealing, a brazing filler metal deposit is formed on the outer peripheral side of each corner of the metalizing layer for sealing. Area becomes wider, a brazing filler metal reservoir of a sufficient size is formed between the metal frame and the metallizing layer for sealing, and the metal frame and the metallizing layer for sealing are firmly joined. Become so. Therefore, after the metal lid is attached to the metal frame by welding by the seam weld method or by brazing with a brazing material such as gold-tin, the metal lid and the metal frame are thermally shrunk to cause thermal stress. Even if occurs, the metal frame does not peel off from the sealing metallization layer, and it is possible to provide a package for storing electronic components having excellent airtightness and reliability.

Further, when the radius of curvature of the roundness of the outer circumference at each corner of the metal frame is 0.05 to 0.50 mm larger than the radius of curvature of the roundness of the outer circumference at each corner of the metallizing layer for sealing, the sealing is performed. The area where the brazing filler metal is formed in each corner portion is increased without unnecessarily increasing the metallization layer for use, and it is possible to form a brazing filler metal reservoir having a sufficient size while achieving miniaturization of the package, The bonding strength between the metal frame body and the sealing metallization layer is increased.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of an embodiment of an electronic component storing package according to the present invention, with a lid removed.

FIG. 2 is a side view showing an example of an embodiment of a package for housing an electronic component of the present invention.

FIG. 3 is a plan view showing an example of a conventional electronic component storage package with a lid removed.

FIG. 4 is a side view showing an example of a conventional electronic component storage package.

[Explanation of symbols]

1 ... Insulating substrate 2 ... Metallization layer for sealing 3 ... Metal frame 4 ... Lid 5 ... Electronic parts 6 ... Mounting part 7 ... Wiring conductor 9 ... Roundness of the outer periphery of the corner of the metal frame 10 ... Roundness of the outer periphery of the corner of the metallizing layer for sealing

Claims (2)

[Claims] 1. An insulating substrate comprising a substantially quadrangular plate-shaped body, having a mounting portion on which an electronic component is mounted and a wiring conductor electrically connected to an electrode of the electronic component in the vicinity of the mounting portion. A square frame-shaped sealing metallization layer having a rounded outer periphery of a corner portion attached to the upper surface of the insulating base so as to surround the mounting portion, and a brazing material on the upper surface of the sealing metallization layer. A square frame-shaped metal frame body having a rounded outer periphery of the corner portions joined together, and a lid body attached to the upper surface of the metal frame body so as to cover the electronic component mounted on the mounting portion. And the radius of curvature of the roundness of the outer periphery of the corner of the metal frame is determined by positioning the outer periphery of the corner of the metal frame inside the outer periphery of the corner of the metallizing layer for sealing. It is characterized in that it is made larger than the radius of curvature of the roundness of the outer periphery of the corner of the layer Package for storing electronic components. 2. The radius of curvature of the roundness of the outer periphery of the corner of the metal frame is 0.05 to 0.50 mm larger than the radius of curvature of the roundness of the outer periphery of the corner of the metallizing layer for sealing. Package for storing electronic components described in 1.