JP2813074B2 - Package for storing semiconductor elements - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Conventionally, a semiconductor element housing package for housing a semiconductor element, particularly a semiconductor integrated circuit element such as an LSI, is generally made of an electrically insulating material such as alumina ceramics, and has a semiconductor integrated circuit located substantially at the center of its upper surface. Has a recess for accommodating the element, and tungsten (W) on the upper surface
An insulating base having a metallized wiring layer made of a high melting point metal powder such as molybdenum (Mo), and a brazing material such as silver braze in the metallized wiring layer for electrically connecting a semiconductor integrated circuit element to an external electric circuit. A semiconductor integrated circuit element is mounted on the bottom surface of the concave portion of the insulating base, and comprises an external lead terminal attached through the outer lead terminal and a metal lid made of metal such as Kovar metal or 42 alloy. Each electrode of the element and the metallized wiring layer are connected via a bonding wire, and a metal lid is joined to the upper surface of the insulating substrate with a sealing material made of a gold-tin alloy (Au-Sn alloy) or the like. A semiconductor device as a final product is obtained by hermetically sealing a semiconductor integrated circuit element inside a container formed of a metal lid and a metal lid.

In recent years, however, the size of semiconductor integrated circuit devices and the speed of signal propagation have rapidly increased, and when the semiconductor integrated circuit devices are housed in the conventional semiconductor device housing package, the following will be described. It has disadvantages.

That is, (1) the coefficient of thermal expansion of silicon constituting a semiconductor integrated circuit element and the coefficient of thermal expansion of alumina ceramic constituting an insulating base of a package are 3.0 to 3.5 × 10 ^-6 /
℃, 6.0 to 7.5 × 10 ^-6 / ℃, greatly different from the heat generated when operating the semiconductor integrated circuit element and the like is applied to both, a large thermal stress occurs between the two,
The thermal stress damages the semiconductor integrated circuit element or peels off from the insulating base to cause the semiconductor device to lose its function as a semiconductor device.

(2) Since the dielectric constant of alumina ceramic constituting the insulating base of the package is as high as 9 to 10 (room temperature 1 MHz), the propagation speed of the signal transmitted through the metallized wiring layer provided on the insulating base is slow, and A semiconductor integrated circuit element that requires high-speed propagation has a drawback that it cannot be mounted and accommodated.

Therefore, in order to solve the above-mentioned drawback, the thermal expansion coefficient of the silicon constituting the semiconductor integrated circuit device (3.0 to 3.5 × 10 ^-6 / ° C.) is approximated by replacing the insulating base of the semiconductor device housing package with alumina ceramics. Thermal expansion coefficient 4.
Use of a mullite sintered body having a temperature of 0 to 4.5 × 10 ⁻⁶ / ° C. and a low dielectric constant of 6.3 has been studied.

[0007]

However, when the mullite sintered body is used as an insulating base of a package, the metal cover is bonded to the insulating base via a sealing material such as a gold-tin alloy. The coefficient of thermal expansion of the substrate (mullite sintered body) and the metal lid (Kovar metal or 42 alloy) are different from 4.0 to 4.5 × 10 ^-6 / ° C and 5.2 to 6.0 × 10 ^-6 / ° C, respectively. From the thermal stress due to the difference in the coefficient of thermal expansion of the two is inherent in the joint, as a result, even if a small external force is applied to the metal lid, the external force increases rapidly with the intrinsic stress, metal There has been a problem that the lid body is peeled off from the insulating base.

[0008]

According to the present invention, there is provided a semiconductor element housing package comprising a metal lid and an insulating base having a concave portion for housing a semiconductor element, wherein the insulating base is formed of a mullite sintered body. A metal cover is provided on the outer surface of the core made of copper with a coating layer made of an alloy of 28.5 to 29.5% by weight of nickel, 15.5 to 16.5% by weight of cobalt, and 54.0 to 56.0% by weight of iron. It is characterized by being formed of a metal body adhered so that the area is 7.2 to 8.8 times the cross-sectional area of the core body.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the embodiments shown in the accompanying drawings.

FIG. 1 is a sectional view showing one embodiment of a package for housing a semiconductor element according to the present invention, wherein 1 is an insulating base, and 2 is a metal lid. A container 3 for accommodating the semiconductor integrated circuit device 4 with the insulating base 1 and the metal lid 2.
Is configured.

The insulating substrate 1 is provided with a stepped recess A for forming a space for accommodating the semiconductor integrated circuit element 4 at the center of the upper surface thereof, and the semiconductor integrated circuit element 4 is adhered to the bottom of the recess A. It is attached via materials.

The insulating substrate 1 is made of a mullite sintered body, and the mullite sintered body has a thermal expansion coefficient of 4.0 to 4.5.
× 10 ⁻⁶ / ° C., which is close to the coefficient of thermal expansion (3.0 to 3.5 × 10 ⁻⁶ / ° C.) of the silicon constituting the semiconductor integrated circuit element 4.
Even if heat generated when the semiconductor integrated circuit element 4 is operated is applied to both of them after mounting and housing 4, no large thermal stress is generated between the two. The integrated circuit element 4 is not damaged or peeled from the insulating base 1.

[0013] The insulating substrate 1 made of the mullite sintered body, for example, mullite _{(3 Al 2 O 3 · 2SiO} 2), silica (SiO _2), magnesia (MgO), raw material powders such as calcia (CaO) An appropriate organic solvent and a solvent are added and mixed to form a slurry, and this is formed into a ceramic green sheet (ceramic green sheet) by employing a doctor blade method. Thereafter, the ceramic green sheet is appropriately punched. Applying processing and laminating multiple sheets,
It is manufactured by firing at a high temperature (1400-1800 ° C).

A metallized wiring layer 5 is formed on the insulating base 1 from the periphery of the concave portion A to the outside of the container 3, and each electrode of the semiconductor integrated circuit element 4 is formed around the concave portion A of the metallized wiring layer 5. Are electrically connected via bonding wires 6, and external lead terminals 7 connected to an external electric circuit are attached to a portion led out of the container 3 via a brazing material 8 such as silver brazing. .

The metallized wiring layer 5 is made of tungsten,
It is made of a high melting point metal powder such as molybdenum, and is formed so as to be led out of the container 3 from the periphery of the concave portion A of the insulating substrate 1 by employing a conventionally known thick film method such as a screen printing method.

Since the metallized wiring layer 5 has a low dielectric constant of 6.3, which is a mullite sintered body constituting the insulating substrate 1, it is possible to make the propagation speed of an electric signal transmitted through the metallized wiring layer extremely high. It is also possible to accommodate therein a semiconductor integrated circuit element 4 that performs high-speed driving with a high signal propagation speed.

An external lead terminal 7 brazed to the metallized wiring layer 5 serves to connect the semiconductor integrated circuit element 4 housed therein to an external electric circuit, and connects the external lead terminal 7 to the external electric circuit. As a result, the semiconductor integrated circuit element 4 accommodated inside is
In addition, it is electrically connected to an external electric circuit via the external lead terminal 7.

The external lead terminal 7 is made of Kovar metal or 42
Ingots made of metals such as Alloy and Kovar metals
(Lump) is formed into a predetermined plate shape by employing a conventionally known rolling method.

On the upper surface of the insulating substrate 1, a metallized metal layer 9 is adhered. On the metallized metal layer 9, a metal cover 2 is provided with a sealing material 10 such as a gold-tin alloy. Are joined through.

The metallized metal layer 9 on the upper surface of the insulating substrate 1
Is made of a high melting point metal powder such as tungsten or molybdenum, and a metal paste obtained by adding and mixing an appropriate organic solvent and a solvent to the tungsten powder or the like is printed and applied on the upper surface of the insulating substrate 1 by a conventionally known screen printing method. At the same time, by baking this at a high temperature, it is formed on the upper surface of the insulating substrate 1.

The metal cover 2 bonded to the metallized metal layer 9 has a nickel core 28.5 on the outer surface of a copper core.
~ 29.5 wt%, cobalt 15.5 ~ 16.5 wt%, iron 54.0
A metal layer having a cross-sectional area of 7.20 to 8.8 times the cross-sectional area of the core body, and a coefficient of thermal expansion of 4.7 to 4.9. × 1
0 ^-6 / ° C.

The metal lid 2 has a thermal expansion coefficient of 4.7.
4.9 × 10 ⁻⁶ / ° C., which is close to the coefficient of thermal expansion of the mullite sintered body composing the insulating substrate 1, so that the metalized metal layer 9 applied to the insulating substrate 1 2 are bonded via the sealing material, the insulating base 1 and the metal lid 2
No large thermal stress due to the difference in the coefficient of thermal expansion between the two occurs, and no large stress is inherent in the joint between the two. Therefore, after joining, the metal lid 2
Even if an external force is applied to the metal cover, the external force becomes large rapidly with the stress existing in the joint, and the metal cover 2 does not peel off from the insulating base 1.

The metal lid 2 has, for example, 28.5 to 29.5% by weight of nickel and 15.5 to 29.5% by weight of cobalt on the outer surface of a copper material.
A nickel-cobalt-iron alloy alloyed by heating and melting 16.5% by weight and 54.0 to 56.0% by weight of iron is brought into contact with the alloy and then rolled by a rolling roller.

When the amount of nickel, cobalt and iron and the ratio of the cross-sectional area of the core to the cross-sectional area of the coating layer are out of the above-mentioned ranges, the coefficient of thermal expansion of the metal lid 2 becomes insulated. It becomes too large for the mullite sintered body constituting the base 1, and as a result, the metal lid 2 cannot be firmly attached to the insulating base 1. Therefore, the metal lid 2 is formed of nickel 28.5 to 28.5 on the outer surface of the copper core.
9.5% by weight, cobalt 15.5 to 16.5% by weight, iron 54.0 to 5
It is specified that a coating layer made of a 6.0% by weight alloy is formed of a metal body applied so that the cross-sectional area of the coating layer is 7.2 to 8.8 times the cross-sectional area of the core body.

The metallized metal layer 9 and the metal lid 2 may be formed by plating a metal having excellent corrosion resistance, such as nickel or gold, to a thickness of 2.0 to 20.0 μm on the exposed outer surfaces thereof by plating. Metallized metal layer 9 and metal lid 2
Can be effectively prevented from oxidative corrosion and discoloration. Therefore, it is preferable to coat nickel, gold or the like on the exposed outer surfaces of the metallized metal layer 9 and the metal lid 2 to a thickness of 2.0 to 20.0 μm in order to effectively prevent discoloration due to oxidative corrosion.

Thus, according to the package for accommodating a semiconductor device of the present invention, the semiconductor integrated circuit device 4 is attached to the bottom surface of the concave portion A of the insulating base 1 via an adhesive, and each electrode of the semiconductor integrated circuit device 4 is connected to the metallized wiring layer 5. Then, a metal lid 2 is bonded to the upper surface of the insulating base 1 via a sealing material such as a gold-tin alloy, and the inside of the container 3 is hermetically sealed. By stopping, a semiconductor device as a product is obtained.

It should be noted that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention. For example, the external lead terminal 7 can be connected to the metal cover 2. 28.5% to 29.5% by weight of nickel and 15.5% to 1% of cobalt
A coating layer made of an alloy of 6.5% by weight and iron of 54.0 to 56.0% by weight is provided so that the cross-sectional area of the coating layer is 7.2 to 8.8 of the cross-sectional area of the core body.
The use of a metal body adhered so as to be twice as large makes the attachment of the external lead terminals 7 to the insulating base 1 extremely strong. Therefore, in order to attach the external lead terminal 7 to the insulating substrate 1 very firmly, the external lead terminal 7 is attached to the outer surface of the copper core by 28.5 to 29.5% by weight of nickel and 15.5% by weight of cobalt.
And a coating layer made of an alloy containing 54.0 to 56.0% by weight of iron and having a cross-sectional area of 7.2 to
It is preferable that the metal body is formed so as to be 8.8 times larger.

Further, a metal having excellent corrosion resistance and good conductivity, such as nickel or gold, may be plated on the exposed outer surface of the external lead terminal 7 to a thickness of 2.0 to 20.0 μm by plating. Can be effectively prevented from being oxidized and corroded and discolored, and the electrical connection between the external lead terminal 7 and the external electric circuit can be made extremely good. Accordingly, in order to effectively prevent discoloration of the external lead terminal 7 due to oxidative corrosion and to improve the electrical connection with an external electric circuit, nickel, gold or the like is coated on the exposed external surface of the external lead terminal 7 with 2.0 to 20.0%. It is preferable to coat the layer to a thickness of μm.

[0029]

According to the package for accommodating a semiconductor element of the present invention, since the insulating base is formed of a mullite sintered body, the thermal expansion coefficient of the insulating base can be approximated to the thermal expansion coefficient of the semiconductor integrated circuit element. As a result, even if heat generated when the semiconductor integrated circuit element is operated or the like is applied to both the insulating base and the semiconductor integrated circuit element after the semiconductor integrated circuit element is accommodated in the insulating container, the semiconductor integrated circuit element can be interposed between the two. Does not generate a large thermal stress, and the thermal stress does not damage the semiconductor integrated circuit element or peel off from the insulating base.

Further, since the insulating base made of a mullite sintered body has a low dielectric constant of 6.3, the propagation speed of an electric signal transmitted through the metallized wiring layer provided on the insulating base can be made extremely high. In addition, a semiconductor integrated circuit element that performs high-speed driving can be accommodated in the insulating container.

Further, a metal lid is formed on the outer surface of a core body made of copper at 28.5 to 29.5% by weight of nickel, and at 15.5 to 16.5% of cobalt.
% Of iron and 54.0 to 56.0% by weight of an alloy. The coating layer was formed of a metal body applied such that the cross-sectional area of the coating layer was 7.2 to 8.8 times the cross section of the core. The expansion coefficient can be approximated to that of the insulating base. As a result, when the metal lid is joined to the upper surface of the insulating base, the difference between the thermal expansion coefficient between the insulating base and the metal lid is caused by the difference between the two. Almost no thermal stress is generated, and the metal lid can be bonded very firmly to the upper surface of the insulating base, so that a highly reliable semiconductor element housing package can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of a semiconductor element storage package according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Insulating base 2 ... Metal lid 3 ... Container 5 ... Metallized wiring layer 7 ... External lead terminal 9 ... Metallized metal layer 10 ... Sealing material A ... Recess

Claims (1)

(57) [Claims] 1. A semiconductor element housing package comprising an insulating base having a recess for housing a semiconductor element and a metal lid, wherein the insulating base is formed of a mullite sintered body, and wherein the metal lid is provided. On the outer surface of a core made of copper, a coating layer made of an alloy of 28.5 to 29.5% by weight of nickel, 15.5 to 16.5% by weight of cobalt, and 54.0 to 56.0% by weight of iron, and the cross-sectional area of the coating layer is the cross-sectional area of the core. A package for accommodating a semiconductor element, which is formed of a metal body adhered so as to be 7.2 to 8.8 times as large as the above.