JP2000340687A - Package for storing semiconductor elements - Google Patents

Abstract

(57) Abstract: A conductive adhesive for bonding an insulating substrate and a metal lid is likely to be separated from the insulating substrate. SOLUTION: A mounting portion 1a of a semiconductor element 3, a frame-shaped sealing region 1b surrounding the mounting portion 1a, and a metallized conductor layer for grounding provided in a part of the sealing region 1b are provided on an upper surface of an insulating base 1 made of ceramics. 5a, a metal lid 2 is bonded by a sealing region 1b by a conductive adhesive 6, and seals the semiconductor element 3 and a metallized conductor layer 5 for grounding.
and a narrow portion 7a on a top surface of the sealing region 1b for exposing a part of the ground metallized conductor layer 5a into the sealing region 1b.
Alternatively, a frame-shaped ceramic thick film 7 having an opening 7b is applied. The insulating base 1 and the lid 2 can be firmly joined by the ceramic thick film 7, and the ground metallized conductor layer 5a and the lid 2 can be electrically connected well.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device housing package for housing a semiconductor device.

[0002]

2. Description of the Related Art FIG. 4 is a perspective view showing a conventional semiconductor device housing package for housing a semiconductor device.
As shown in the cross-sectional view of FIG. 1, the upper surface has a mounting portion 11a on which the semiconductor element 13 is mounted, and is led out from the periphery of the mounting portion 11a to the lower surface via a via hole. And an insulating substrate 11 having a plurality of metallized conductor layers 15 extending on the side surfaces.
There is known a semiconductor element housing package including a metal lid 12 bonded to the upper surface of the insulating base 11 and sealing the semiconductor element 13.

In such a package for housing a semiconductor element, a frame-shaped sealing region 11b is provided on the upper surface of the insulating base 11 so as to surround the mounting portion 11a. Metallized metal layer 17 is applied. Then, the insulating base 11 and the lid 12 are joined by brazing the metal lid 12 to the metallized metal layer 17 for sealing via a low melting point brazing material 16 such as a gold-tin alloy.

[0004] Of the metallized conductor layers 15, a metallized conductor layer 15a for grounding is electrically connected to the metallized metal layer 17, so that the lid 12 is connected to the metallized metal layer 17 via the brazing material 16. , The lid 12 is connected to the ground potential, and functions as an electromagnetic shield for the semiconductor element 13.

[0005]

However, the brazing material made of a gold-tin alloy contains about 80% by weight of gold and is expensive, and its melting temperature is as high as about 280 ° C. There is a problem that a large heat load is applied to the semiconductor element inside the package when the cover and the lid are joined.

Therefore, instead of the brazing material made of a gold-tin alloy, a metallized metal layer and a metal cover, which are applied to the sealing region of the insulating substrate with a conductive adhesive such as silver-epoxy resin, are used. Can be joined. According to this conductive adhesive, silver is less expensive than gold, and epoxy resin is thermoset at a temperature of about 100 to 150 ° C.,
There is an advantage that the thermal load on the semiconductor element inside the package is small when the insulating base and the lid are joined.

However, the metallized metal layer applied to the sealing region of the insulating substrate is generally provided with a nickel plating layer and a gold plating layer on the surface in order to prevent oxidative corrosion. Since the epoxy resin has poor adhesion to a metallized metal layer having a nickel plating layer and a gold plating layer adhered to the surface thereof, heat generated during operation of the semiconductor element is reduced by an insulating substrate and a metal lid. When applied to both, a thermal stress is generated due to the difference in the coefficient of thermal expansion between the two, and when this is repeatedly applied between the two, a conductive adhesive made of silver-epoxy resin and a metallized metal layer Separation occurs between the
The semiconductor element is incompletely sealed, which causes a problem that the semiconductor element housed therein cannot be operated stably and normally for a long period of time.

The present invention has been devised in view of the conventional problems, and has as its object to seal an insulating base and a metal lid at a low cost and at a low temperature with silver-epoxy resin or the like. An object of the present invention is to provide a package for housing a semiconductor element, which can be firmly joined by using a conductive adhesive and can electrically connect a metalized conductor layer for grounding and a metal lid well.

[0009]

According to the present invention, there is provided a package for accommodating a semiconductor device, comprising: a mounting portion on which a semiconductor device is mounted; a frame-shaped sealing region surrounding the mounting portion; A metal lid having a ground metallization conductor layer disposed in a part of the sealing region, wherein a metal lid is bonded to the sealing region with a conductive adhesive so as to cover the semiconductor element; And a semiconductor element housing package electrically connected to the grounded metallized conductor layer, wherein a part of the grounded metallized conductor layer is formed on the upper surface of the sealing region in the sealing region. A ceramic thick film in the form of a frame provided with a narrow portion or an opening to be exposed on the substrate.

According to the package for accommodating a semiconductor element of the present invention, a frame-shaped ceramic thick film is formed on the upper surface of the sealing region, and a narrow portion or opening for exposing a part of the ground metallized conductor layer in the sealing region. The ceramic thick film and the lid can be bonded very firmly with a conductive adhesive because the ceramic thick film and the lid are attached to the metallized conductor layer for grounding exposed in the sealing region. Can be electrically connected favorably by the conductive adhesive.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The package for accommodating a semiconductor device according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view showing an example of an embodiment of a semiconductor device housing package according to the present invention, and FIG.
FIG. 3 is a cross-sectional view of the semiconductor device storage package shown in FIG. The package for accommodating a semiconductor element according to the present invention is mainly composed of an insulating base 1 and a metal lid 2, and the semiconductor element 3 is sealed therebetween.

The insulating substrate 1 is made of a ceramic material such as a sintered body of aluminum oxide, a sintered body of aluminum nitride, a sintered body of mullite, a sintered body of silicon carbide, a sintered body of silicon nitride, and a glass ceramic. It is a substantially rectangular flat plate,
It functions as a support member for supporting the semiconductor element 3 to be mounted.

When the insulating substrate 1 is made of, for example, an aluminum oxide sintered body, a suitable organic binder and a solvent are added to a raw material powder such as aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, etc. and mixed. A ceramic green sheet is obtained by forming a sheet and adopting a conventionally known doctor blade method, and a ceramic green sheet is subjected to an appropriate punching process and a plurality of sheets are laminated as necessary. A green ceramic laminate is manufactured by finally firing the green ceramic body at a temperature of about 1600 ° C. in a reducing atmosphere.

A semiconductor element 3 is provided at the center of the upper surface of the insulating base 1.
The mounting part 1a for mounting is formed. A metallized metal layer 4 is adhered to the mounting portion 1a, and a semiconductor element 3 is bonded and fixed on the metallized metal layer 4 via a conductive adhesive (not shown) such as silver-epoxy resin. Is done.

The metallized metal layer 4 is provided for connecting the lower surface of the semiconductor element 3 to a predetermined ground potential. Of the metallized wiring conductors 5 described later, a through hole is formed in the metallized wiring conductor 5a for grounding. And via holes or other through conductors.

A plurality of metallized conductor layers 5 electrically connected to the respective electrodes (ground electrode, power supply electrode, signal electrode) of the semiconductor element 3 are led out around the mounting portion 1a of the insulating base 1. Each electrode of the semiconductor element 3 is connected to the metallized conductor layer 5 via a bonding wire 8.

The metallized conductor layer 5 functions as a conductive path for connecting the electrodes of the semiconductor element 3 to an external electric circuit, and a through conductor (not shown) penetrating vertically through the insulating base 1 from around the mounting portion 1a. ), Is led out to the lower surface of the insulating base 1 and extends therefrom to the side surface of the insulating base 1.
Then, the lower surface portion and the side surface portion of the insulating base 1 of the metallized conductor layer 5 function as terminals for external connection, and are electrically connected to wiring conductors of the external electric circuit board via, for example, solder.

Each of the metallized metal layer 4 and the metallized conductor layer 5 is made of tungsten or molybdenum.
It is made of metal powder such as copper, silver, silver-palladium, molybdenum-manganese, etc. For example, when it is made of tungsten metallization, a metal paste obtained by adding and mixing an appropriate organic binder and solvent to tungsten powder is used as an insulating substrate. By applying a conventionally known screen printing method to a ceramic green sheet to be printed in a predetermined pattern and firing it together with the ceramic green sheet, a predetermined pattern is formed on a predetermined position of the insulating substrate 1. Is done.

The exposed surfaces of the metallized metal layer 4 and the metallized conductor layer 5 are preferably coated with a nickel plating layer and a gold plating layer sequentially. Thereby, oxidation corrosion of the metallized metal layer 4 and the metallized conductor layer 5 is effectively prevented, and the metallized conductor layer 5
And the bonding wires 8 and the metallized conductor layer 5 and the wiring conductor of the external electric circuit board can be easily and firmly connected.

A rectangular frame-shaped sealing region 1b having a width of about 0.5 to 5 mm is provided on the outer peripheral portion of the upper surface of the insulating base 1 so as to surround the mounting portion 1a.

The sealing region 1b is a region for joining the lid 2 to the insulating base 1, and the metal lid 2 is joined on the sealing region 1b via the conductive adhesive 6. .

The metallized conductor layer 5a for grounding is provided on a part of the sealing region 1b so as to extend therefrom, and a frame-shaped ceramic thick film 7 is further applied thereon.

The ground metallized conductor layer 5a disposed in the sealing region 1b is for connecting the lid 2 joined to the sealing region 1b via the conductive adhesive 6 to a predetermined ground potential. And a part thereof is exposed on the surface of the sealing region 1b without being covered with the ceramic thick film 7. As described above, since a part of the ground metallized conductor layer 5a extending to the sealing region 1b is exposed to the sealing region 1b without being covered by the ceramic thick film 7, the lid 2 is electrically conductively bonded. When bonding to the sealing region 1b via the agent 6, the conductive adhesive 6 bonded to the sealing region 1b and the metallized conductor layer 5a for grounding come into electrical contact, thereby setting the lid 2 to the ground potential. It becomes possible.

The width and length of the exposed metallized conductor layer 5a in the sealing region 1b are each 0.1 mm.
It is preferable that it is above. Ground metallized conductor layer 5
a is exposed to the sealing region 1b and the width and length are each
When the thickness is less than 1 mm, when the lid 2 is bonded to the sealing region 1b via the conductive adhesive 6, the conductive adhesive 6 and the ground metallized conductor layer 5a do not make good contact with each other and the ground metallization There is a large risk that the conductor layer 5a and the lid 2 cannot be electrically connected well.

The ceramic thick film 7 is made of a ceramic such as an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, a silicon carbide sintered body, a silicon nitride sintered body, a glass ceramic or the like. And has substantially the same width as the sealing region 1b except for a part thereof. And its thickness is about 10 to 100 μm.

The ceramic thick film 7 functions as a joining strength improving member for firmly joining the sealing region 1b and the conductive adhesive 6, and the ceramic forming the same is made of epoxy resin or the like as compared with metal. Since it is firmly bonded to the adhesive, it is strongly bonded to the conductive adhesive 6 made of silver-epoxy resin or the like.

When the center line average roughness (Ra) of the upper surface of the ceramic thick film 7 is set to Ra ≧ 0.65 μm,
The irregularities on the surface of the ceramic coating 7 and the conductive adhesive 6 are engaged with each other, so that they can be more firmly joined. Therefore, it is preferable that the center line average roughness (Ra) of the upper surface of the ceramic film 7 be set to Ra ≧ 0.65 μm.

Further, the ceramic thick film 7 is formed on the insulating substrate 1.
If the insulating substrate 1 and the ceramic thick film 7 are formed of a ceramic material having substantially the same composition as the above, the thermal expansion coefficients of the insulating substrate 1 and the ceramic thick film 7 become substantially the same, and for example, the semiconductor element 3 operates on the insulating substrate 1 and the ceramic thick film 7. Even if the heat generated occasionally is repeatedly applied, no thermal stress is generated between the two due to the difference in the thermal expansion coefficient, and it is possible to effectively prevent the ceramic thick film 7 from peeling or cracking. Therefore, it is preferable that the ceramic thick film 7 is formed of a ceramic material having substantially the same composition as the insulating base 1.

Further, the sealing region 1 is formed on the ceramic thick film 7.
A part of the grounded metallized conductor layer 5a extending to the portion b is exposed to the sealing region 1b. For example, a notch-shaped narrow portion 7a is provided on the inner peripheral side.

The ceramic thick film 7 forms a part of the metallized conductor layer 5a for grounding disposed in the sealing region 1b with the sealing region 1b.
When the metal lid 2 is joined to the sealing region 1b by the conductive adhesive 6, the metallized conductor layer 5a for grounding, the metal lid 2 Are electrically connected to each other through the conductive adhesive 6 in the narrow portion 7a. Thus, the metal lid 2 can be set at the ground potential, and the lid 2 can function as an electromagnetic shield for the semiconductor element 3.

The width of the ceramic thick film 7 covering the ground metallized conductor layer 5a in the sealing region 1b is 0.1 m.
m or more. The width of the ceramic thick film 7 covering the ground metallized conductor layer 5a in the sealing region 1b is
If the thickness is less than 0.1 mm, when the lid 2 is bonded to the sealing region 1b with the conductive adhesive 6, the adhesion between the sealing region 1b and the conductive adhesive 6 in this portion is weak, and The danger that the lid 2 cannot be firmly joined becomes large.

When the ceramic thick film 7 is made of, for example, an aluminum oxide sintered body, a suitable organic binder and a solvent are added to a raw material powder such as aluminum oxide, silicon oxide, calcium oxide, and magnesium oxide. The obtained ceramic paste is printed in a frame shape on a ceramic green sheet serving as the insulating substrate 1 by employing a conventionally known screen printing method, and is fired together with the ceramic green sheet to form a sealing region 1b on the upper surface of the insulating substrate 1.
Is formed in a predetermined frame shape.

The surface roughness of the upper surface of the ceramic thick film 7 obtained by printing and applying a ceramic paste by screen printing and firing the ceramic paste is as follows.
Compared to the insulating substrate 1 obtained by firing the ceramic green sheet, the substrate tends to be rough, and a surface roughness satisfying Ra ≧ 0.65 μm in center line average roughness (Ra) can be easily obtained.

On the other hand, the metal lid 2 joined to the sealing region 1b is formed by pressing a plate of, for example, an iron-nickel-cobalt alloy or an iron-nickel alloy into a bowl shape.
A flange is formed in the opening. Then, by joining this flange portion to the sealing region 1b via the conductive adhesive 6, the lid 2 is joined to the insulating base 1 and is also electrically connected to the ground metallized conductor layer 5a.

Thus, according to the package for accommodating a semiconductor element of the present invention, the semiconductor element 3 is bonded and fixed to the mounting portion 1a of the insulating base 1, and each electrode of the semiconductor element 3 is electrically connected to the corresponding metallized conductor layer 5 respectively. And finally bonding the lid 2 to the sealing region 1b of the insulating base 1 via the conductive adhesive 6, so that the lid 2 is firmly bonded to the insulating base 1 and Grounded metallized conductor layer 5a is electrically connected.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention. For example, in one example of the above-described embodiment, a part of the metallized conductor layer 5a for grounding is provided in the sealing region 1b by providing the narrow portion 7a in which the inner peripheral side of the ceramic thick film 7 is cut out. However, a part of the ground metallized conductor layer 5a is exposed in the sealing region 1b by providing the narrow width portion 7a by removing the outer peripheral side of the ceramic thick film 7 in a notch shape. You may. Alternatively, as shown in a perspective view in FIG. 3, by providing an opening 7b between the inner periphery and the outer periphery of the ceramic thick film 7, a part of the ground metallized conductor layer 5a is exposed in the sealing region 1b. It may be.

Further, in the above-described embodiment, the ground metallized conductor layer 5a is provided so as to extend from the side surface of the insulating base to the sealing region 1b. Similarly, as shown in FIG. 3, the sealing region 1b
The metallized metal layer 4 may extend from the grounded metallized conductor layer 5a located inside the metallized metal to the sealing region 1b, or the metallized metal layer 4 may be electrically connected to the grounded metallized conductor layer 5a. Layer 4 to sealing region 1b
It may be disposed so as to extend to the outside. Further, by connecting to a through conductor led into the sealing region 1b from a grounding conductor layer provided inside or on the back side of the insulating base 1,
It may be formed in a pad shape and arranged.

[0039]

According to the semiconductor device housing package of the present invention, a frame-shaped ceramic thick film is formed on the upper surface of the sealing region, and a part of the metallized conductor layer for grounding disposed in a part of the sealing region. The ceramic thick film and the conductive adhesive can be bonded very firmly because they are applied so as to be exposed in the sealing region, and the metallized conductor for grounding exposed in the sealing region A semiconductor element having high sealing reliability and excellent electromagnetic shielding properties by using a metal lid because the layer and the metal lid can be electrically connected well via a conductive adhesive. A storage package can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of an embodiment of a semiconductor device housing package of the present invention.

FIG. 2 is a cross-sectional view of the package for housing a semiconductor element shown in FIG. 1;

FIG. 3 is a perspective view showing an insulating base in another embodiment of the semiconductor element housing package of the present invention.

FIG. 4 is a perspective view showing a conventional semiconductor element storage package.

5 is a cross-sectional view of the package for housing a semiconductor element shown in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Insulating base 1a ... Mounting part 1b ... Sealed area 2 ... Metal cover 3 ... Semiconductor element 5 ... Metallized conductor layer 5a ... Metallized conductor layer for grounding 6 ... Conductive adhesive 7 ... Ceramic thick film 7a ... Narrow Width portion 7b ... opening

Claims (2)

[Claims] 1. A mounting portion on which a semiconductor element is mounted, a frame-shaped sealing region surrounding the mounting portion, and a ground metallization disposed in a part of the sealing region on an upper surface of an insulating base made of ceramics. A conductive lid, and a metal lid is bonded to the sealing region with a conductive adhesive so as to cover the semiconductor element, and seals the semiconductor element and electrically connects the grounded metallized conductive layer. A package having a narrow portion or an opening provided on the upper surface of the sealing region to expose a part of the metallized conductor layer for grounding in the sealing region. A semiconductor element storage package characterized by having a ceramic thick film applied thereon. 2. The ceramic thick film is made of substantially the same material as the insulating substrate, and has an upper surface having a center line average roughness (Ra) of Ra ≧ 0.65 μm. The package for housing a semiconductor element according to the above.