JP2002158305A - Electronic component storage package - Google Patents

Abstract

(57) [Summary] [Problem] After welding a metal lid body to a metal frame brazed to a brazing metallization layer, peeling occurs in the brazing metallization layer, so that the hermetic reliability of the package is low. . SOLUTION: A mounting section 1 on which an electronic component 4 is mounted on an upper surface.
a metal frame 2 having a substantially square frame shape with rounded corners on the inner and outer peripheral surfaces is attached to the upper surface of the insulating base 1 having a. In the electronic component storage package in which the metal lid 3 is joined to the metal cover 2, the radius of curvature of the outer peripheral surface roundness R1 at each corner is smaller than the radius of curvature of the inner peripheral surface roundness R2. Is also big.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a package for accommodating electronic components such as a semiconductor device, a piezoelectric vibrator, and a surface acoustic wave device.

[0002]

2. Description of the Related Art Conventionally, a compact package for accommodating electronic components such as a semiconductor element and a piezoelectric vibrator has been known, as shown in a perspective view in FIG. Sintered body, mullite sintered body,
It is made of an electrically insulating material such as glass-ceramics, and has a concave mounting part for mounting the electronic component 16
An insulating substrate 11 having a plurality of metallized wiring conductors 14 extending from the inside of the mounting portion 11a to the outer peripheral portion of the lower surface and a brazing metallization layer 15 attached on the upper surface so as to surround the mounting portion 11a; An approximately square frame-shaped metal frame made of a metal such as an iron-nickel-cobalt alloy joined to the brazing metallization layer 15 via a brazing material such as silver-copper brazing so as to surround the mounting portion 11a. It comprises a body 12 and a metal lid 13 made of a metal such as an iron-nickel-cobalt alloy joined to the upper surface of the metal frame 12 by a seam welding method or the like.

According to the conventional package for storing electronic components, the electronic component is mounted on the bottom of the mounting portion 11a of the insulating base 11.
16 and the electrodes of this electronic component 16
a, and electrically connected to the metallized wiring conductor 14 in FIG. 1A through an electrical connection means such as solder, conductive resin, bonding wire, or the like. The electronic component 16 is hermetically sealed inside a container including the insulating base 11, the metal frame 12, and the metal lid 13 by welding by a method, thereby forming an electronic device as a product.

[0004] The metal frame 12 is manufactured by punching an iron-nickel-cobalt alloy plate using a punching die. Usually, the inner peripheral surface and the outer peripheral surface have substantially the same corners. The radius of curvature is rounded.

[0005]

However, in such a conventional package for storing electronic parts, rapid downsizing has been promoted in accordance with recent demands for downsizing of electronic devices. The width of the metallization layer 15 for attachment is made as narrow as about 0.2 to 0.3 mm, and the radius of curvature at each corner of the inner peripheral surface and the outer peripheral surface of the metal frame 12 is made as small as about 0.2 to 0.3 mm. . In this way, the width of the brazing metallization layer 15 is made as narrow as about 0.2 to 0.3 mm, and the radius of curvature of each corner of the inner and outer peripheral surfaces of the metal frame 12 is made as small as about 0.2 to 0.3 mm. By doing so, the space for accommodating the electronic component 16 is made as large as possible and the outer shape is made as small as possible.

However, according to such an electronic component storage package, after the electronic component 16 is mounted and fixed on the mounting portion 11a of the insulating base 11, the metal cover 13 is placed on the upper surface of the metal frame 12.
Is welded by the seam welding method or the like, the metal frame 12 and the metal lid 13 that have expanded significantly due to the heat of the welding pull the brazing metallized layer 15 inward by undergoing a large thermal contraction during the cooling process after welding. Large thermal stress is applied. And in the package miniaturized as described above, the width of the brazing metallization layer 15 is 0.
Since the thermal stress applied per unit area of the brazing metallization layer 15 is large because it is as narrow as about 2 to 0.3 mm,
In addition, since the radius of curvature of the roundness formed at each corner of the inner and outer peripheral surfaces of the metal frame 12 is as small as about 0.2 to 0.3 mm, heat is particularly applied to the outer peripheral corner of the metallized layer 15 corresponding to each corner of the outer peripheral surface. The stress is largely concentrated, and the tendency that the outer peripheral corner of the brazing metallization layer 15 is liable to be peeled by the greatly concentrated thermal stress becomes remarkable. For this reason, there has been a problem that the hermetic reliability of an electronic device using the conventional electronic component storage package is greatly impaired.

The present invention has been devised in view of such a conventional problem, and has as its object to weld a metal lid to a metal frame by a seam welding method or the like, and then to form the metal frame and the metal lid. It is an object of the present invention to provide a small-sized electronic component housing package having high hermetic reliability in which a metallizing layer for brazing does not peel off from an insulating substrate even when a thermal stress generated by thermal shrinkage is applied.

[0008]

According to the present invention, there is provided an electronic component storage package comprising: a mounting portion on which an electronic component is mounted; and a substantially rectangular frame-shaped brazing metallization layer surrounding the mounting portion. For brazing metallization layer,
A substantially rectangular frame-shaped metal frame having rounded corners on the inner and outer peripheral surfaces is attached so as to surround the mounting portion, and the metal lid is joined to the metal frame. In the electronic component storage package, the metal frame is characterized in that the radius of curvature of the outer peripheral surface is larger than the radius of curvature of the inner peripheral surface.

According to the electronic component housing package of the present invention, the radius of curvature of the outer peripheral surface at each corner of the metal frame is made larger than the radius of curvature of the inner peripheral surface.
After welding the metal lid to the metal frame by the seam welding method etc., the thermal stress applied to the outer corner of the brazing metallized layer is well dispersed by the roundness of the outer corner of the metal frame having a large radius of curvature. As a result, it is possible to effectively prevent peeling from occurring at the outer corner of the brazing metallization layer. Further, since the radius of curvature of the rounded corner portion is small on the inner peripheral side of the metal frame, the space formed inside the metal frame can be made large.

[0010]

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

FIG. 1 is a perspective view showing an embodiment of an electronic component storage package according to the present invention. In FIG. 1, reference numeral 1 denotes an insulating base, 2 denotes a metal frame, and 3 denotes a metal lid. These mainly constitute a container for housing the electronic component 4 in an airtight manner.

The insulating base 1 has a substantially square shape with a side length of about 2 to 20 mm and a thickness of about 0.5 to 3 mm, and a substantially square concave mounting portion for mounting the electronic component 6 at the center of the upper surface thereof. 1a is provided. The electronic component 6 is mounted and fixed on the mounting portion 1a.

The insulating substrate 1 is made of an electrically insulating material such as a sintered body of aluminum oxide, a sintered body of aluminum nitride, a sintered body of mullite, and a glass-ceramic. If it is, aluminum oxide, silicon oxide, calcium oxide,
Organic binder suitable for raw material powder such as magnesium oxide
A plurality of ceramic green sheets are obtained by adding a solvent and mixing to form a slurry, and forming the sheet into a sheet by employing a conventionally known doctor blade method or the like. Applying appropriate punching and laminating these up and down,
It is manufactured by firing at a temperature of about 1600 ° C.

Further, a plurality of metallized wiring conductors 4 extending from the bottom surface of the mounting portion 1a to the lower surface via the side surface are formed on the insulating substrate 1. Metallized wiring conductor 4
Functions as a conductive path for electrically connecting each electrode of the electronic component 6 mounted on the mounting portion 1a to an external electric circuit, and each electrode of the electronic component 6 is soldered on the bottom surface of the mounting portion 1a. And a portion led out to the lower surface of the insulating base 1 is connected to an external electric circuit through an electrical connection means made of solder or the like. You.

The metallized wiring conductor 4 is made of metallized metal powder such as tungsten, molybdenum, copper, silver, etc., and insulates a metal paste obtained by adding a suitable organic binder and solvent to a metal powder such as tungsten. The ceramic green sheet for the base 1 is printed and applied in a predetermined pattern by a screen printing method, and is fired together with the ceramic green sheet laminate for the insulating base 1 to thereby mount the lower surface of the mounting portion 1a of the insulating base 1 from the bottom to the side. Is formed.

The surface of the metallized wiring conductor 4 is
In order to effectively prevent the metallized wiring conductor 4 from being oxidized and corroded and to improve the connectivity between the metallized wiring conductor 4 and the electrical connection means, it is usual to use nickel having a thickness of about 1 to 10 μm. 0.1 plating layer and thickness
A gold plating layer having a thickness of about 3.0 μm is sequentially applied by a conventionally well-known electrolytic plating method or electroless plating method.

Further, on the upper surface of the insulating base 1, a mounting portion 1 is provided.
A substantially square frame-shaped brazing metallization layer 5 made of metal powder of metal such as tungsten, molybdenum, copper or silver is formed so as to surround a. The brazing metallization layer 5 has a thickness of about 10 to 20 μm and a width of each side of about 0.2 to 0.3 mm, and functions as a base metal for joining the metal frame 2 to the insulating base 1. And
The mounting portion 1a is provided on the upper surface of the brazing metallization layer 5.
Is surrounded by a brazing material such as silver brazing. Such a metallized layer 5 for brazing is formed by adding a suitable organic binder and a solvent to a metal powder such as tungsten and mixing the metal paste to a ceramic green sheet for the insulating substrate 1 in a predetermined pattern by a screen printing method. By printing and applying this and baking it together with the ceramic green sheet laminate for the insulating substrate 1, it is adhered and formed on the upper surface of the insulating substrate 1 so as to surround the mounting portion 1a.

In order to improve the wettability between the brazing metallization layer 5 and the brazing material, the surface of the brazing metallization layer 5 is usually nickel-plated with a thickness of about 0.5 to 5 μm. The layers are pre-applied before brazing.

The metal frame 2 brazed to the brazing metallization layer 5 via a brazing material such as silver brazing is made of a metal such as an iron-nickel alloy or an iron-nickel-cobalt alloy. The lid 3 functions as a base metal member for welding to the insulating base 1. As shown in the top view of the insulating base 1 and the metal frame 2 in FIG. 2, the metal frame 2 has an inner periphery substantially the same size as the opening of the concave portion 1a.
Thickness is about 0.1-0.25mm, width of each side is 0.15-0.25mm
It is about. Further, each corner of the outer peripheral surface has a radius R1 with a radius of curvature of 0.4 to 0.6 mm, and each corner of the inner peripheral surface has a radius R2 with a radius of curvature of 0.2 to 0.3 mm. Then, the metal lid 3 is placed on the metal frame 2, and the metal lid 3 is joined to the metal frame 2 by welding them by, for example, a seam welding method.

In the electronic component storage package of the present invention, it is important that the radius of curvature of the outer peripheral surface roundness R1 at each corner of the metal frame 2 is larger than the radius of curvature of the inner peripheral surface roundness R2. is there. As described above, since the radius of curvature of the radius R1 of the outer peripheral surface at each corner of the metal frame 2 is larger than the radius of curvature of the radius R2 of the inner peripheral surface, the metal lid 3 is seamed on the upper surface of the metal frame 2. The thermal stress generated by the thermal contraction of the metal frame 2 and the metal lid 3 after welding and joining by a welding method or the like is favorably dispersed by the roundness R1 of the outer peripheral corner of the metal frame 2 having a large radius of curvature. As a result, it is possible to effectively prevent the occurrence of peeling at the outer corner of the brazing metallized layer 7. Therefore, according to the electronic component storage package of the present invention, it is possible to obtain an electronic device having excellent airtight reliability. Further, since the radius of curvature of the corner roundness R2 is small on the inner peripheral side of the metal frame 2, the space formed inside the metal frame 2 can be made large.

If the radius of curvature of the roundness R1 of the outer peripheral surface at each corner of the metal frame 2 is less than 0.4 mm, the metal cover 3 is welded to the upper surface of the metal frame 2 by a seam welding method or the like. There is a tendency that it is difficult to satisfactorily disperse the thermal stress generated by the metal frame 2 and the metal lid 3 being thermally contracted after joining. Therefore, the radius of curvature of the roundness R1 of the outer peripheral surface at each corner of the metal frame 2 is 0.4 m.
m or more.

When the radius of curvature of the radius R2 of the inner peripheral surface at each corner of the metal frame 2 exceeds 0.3 mm, the space formed inside the metal frame 2 tends to be narrow. Therefore, the radius of curvature of the radius R2 of the inner peripheral surface at each corner of the metal frame 2 is preferably 0.3 mm or less.

Further, the width W at each corner of the metal frame 2 is
Is less than 0.15 mm, the sealing width at the four corners of the metal frame 2 becomes narrow, and the danger that the hermetic reliability of the package is reduced increases. Therefore, the width W at each corner of the metal frame 2 is preferably 0.15 mm or more.

Such a metal frame 2 is manufactured in a predetermined frame shape by punching out a plate material made of an iron-nickel alloy, an iron-nickel-cobalt alloy or the like by a press machine.

Further, the brazing of the metal frame 2 to the brazing metallization layer 5 is carried out by, for example, placing a foil brazing material having a thickness of 10 to 50 μm on the brazing metallization layer 5. Then, the brazing metallized layer 5 and the metal frame 2 are brazed by heating and melting the brazing material.

The exposed surface of the metallized layer 5 for brazing, the exposed surface of the metal frame 2 and the exposed surface of the brazing material after brazing are oxidized with the metallized layer 5 for brazing, the metal frame 2 and the brazing material. In order to effectively prevent corrosion, usually, 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 formed by a conventionally known electrolytic plating method or electroless plating method. Are sequentially applied.

Thus, according to the electronic component housing package of the present invention, the electronic component 6 is electrically connected to the mounting portion 1a of the insulating base 1 by connecting each electrode thereof to the metallized wiring conductor 4. After mounting and fixing via means
A metal lid 3 is welded to a metal frame 2 brazed to an insulating substrate 1 by a seam welding method or the like, and an electronic component 6 is hermetically sealed therein to provide an electronic device having excellent hermetic reliability. be able to.

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

[0029]

According to the electronic component storage package of the present invention, the radius of curvature of the outer peripheral surface at each corner of the metal frame is made larger than the radius of curvature of the inner peripheral surface. After the body is welded to the metal frame by the seam welding method, the thermal stress applied to the outer peripheral corner of the brazing metallization layer is well dispersed by the roundness of the outer peripheral corner of the metal frame having a large radius of curvature. As a result, peeling does not occur at the outer corner of the brazing metallization layer,
An electronic component storage package having excellent airtight reliability can be provided. Further, since the radius of curvature of the rounded corners is small on the inner peripheral surface of the metal frame, the space formed inside the metal frame can be made large.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of an embodiment of an electronic component storage package according to the present invention.

FIG. 2 is a top view of an insulating base 1 and a metal frame 2 of the electronic component storage package shown in FIG.

FIG. 3 is a perspective view showing a conventional electronic component storage package.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Insulating base 1a ... Mounting part 2 ... Metal frame R1 ... Roundness of the corner of the outer peripheral surface of metal frame 2 R2 ... Inner peripheral surface of metal frame 2 Roundness of corners W: Width of corners of metal frame 2 3: Metal lid 5: Metallized layer for brazing 6: Electronic components

Claims (3)

[Claims] An inner peripheral surface and an outer peripheral surface are formed on a brazing metallization layer of an insulating substrate having a mounting portion on which an electronic component is mounted on an upper surface and a substantially rectangular frame-shaped brazing metallization layer surrounding the mounting portion. A substantially rectangular frame-shaped metal frame having a rounded corner at each corner is attached so as to surround the mounting portion, and a metal lid is joined to the metal frame for electronic component storage. In the package, the metal frame body may have an outer peripheral surface having a radius of curvature larger than that of the inner peripheral surface. 2. The metal frame, wherein the radius of curvature of the outer peripheral surface is 0.4 mm or more, and the radius of curvature of the inner peripheral surface is 0.3 mm or less. The electronic component storage package according to claim 1. 3. The metal frame, wherein each of the corners has a width of 0.5 mm.
The electronic component storage package according to claim 1, wherein the package is 15 mm or more.