JP2750256B2 - 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 a semiconductor device housing package for housing a semiconductor device.

[0002]

2. Description of the Related Art Conventionally, a package for accommodating a semiconductor element, especially a semiconductor integrated circuit element such as an LSI is made of an electrically insulating material such as alumina ceramics, and a semiconductor integrated circuit element is provided substantially at the center of the upper surface thereof. An insulating base having a metallized wiring layer made of a refractory metal powder of tungsten, molybdenum, manganese or the like led out from the periphery of the recess to the outside, and a semiconductor integrated circuit element having an external electric circuit. An external lead terminal attached to the metallized wiring layer via a brazing material such as silver brazing for electrical connection to the metallized wiring layer, and a lid made of an electrically insulating material such as alumina ceramics. The semiconductor integrated circuit device is bonded and fixed to the bottom surface of the concave portion with an adhesive, and each electrode of the semiconductor integrated circuit device and the metallized wiring layer It is electrically connected via bonding wires and the lid is joined to the upper surface of the insulating base with a sealing material made of solder, and the semiconductor integrated circuit element is hermetically sealed inside a container consisting of the insulating base and the lid. By doing so, it becomes a semiconductor device as a product.

In such a conventional package for housing a semiconductor element, a metal layer made of silver-palladium is previously applied to the main surfaces of the insulating substrate and the lid which are opposed to each other by joining the lid to the insulating substrate. It is performed by bonding a metal layer adhered to each of the base and the lid via solder.

[0004]

However, in this conventional package for housing a semiconductor element, the metal layer attached to the lid or the like is made of silver-palladium, and the surface of the silver-palladium is easily oxidized. When an oxide film is formed on the surface, the wettability with the solder is greatly deteriorated, and the bonding strength between the metal layer applied to the insulating base and the lid and the solder as a sealing material is reduced, and finally, Has a disadvantage that it is difficult to firmly join the lid to the insulating base.

In the conventional package for accommodating a semiconductor element, the sealing material for joining the lid to the insulating base is usually made of solder, and its melting point is as high as 295 ° C., so that the insulating base is interposed through the sealing material. When the heat is applied to the semiconductor integrated circuit element housed therein to heat and melt the encapsulant when the cover and the lid are joined, the heat may cause thermal destruction of the semiconductor integrated circuit element, or may cause thermal damage to the characteristics. It also has the disadvantage of causing change.

[0006]

SUMMARY OF THE INVENTION The present invention has been devised in view of the above-mentioned drawbacks, and has as its object the purpose of firmly joining a lid to an insulating base via a sealing material and providing the lid inside a container comprising the insulating base and the lid. An object of the present invention is to provide a package for housing a semiconductor element capable of operating the semiconductor integrated circuit element normally and stably for a long period of time by hermetically sealing the semiconductor integrated circuit element.

[0007]

SUMMARY OF THE INVENTION The present invention comprises an insulating base and a lid, and joins a metal layer adhered to the insulating base and a metal layer adhered to the lid via a sealing material. A semiconductor element housing package for hermetically sealing a semiconductor element therein, wherein at least the metal layer applied to the lid is made of silver-platinum, and the sealing material is tin 2.0 to 6.0.
Wt%, bismuth 2.0 to 10.0 wt%, indium 1.5
Less than 1.5% by weight of silver and less than 1.5% by weight of silver, with the balance being a lead alloy.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 shows an embodiment of a package for housing a semiconductor element according to the present invention, wherein 1 is an insulating base made of an electrically insulating material, and 2 is a lid made of the same electrically insulating material. This insulating substrate
The container 1 for accommodating the semiconductor integrated circuit element 4 is composed of the lid 1 and the lid 2.

The insulating base 1 is provided with a stepped recess 1a at the center of the upper surface thereof to form a space for accommodating the semiconductor element 4, and the semiconductor integrated circuit element 4 is made of glass, It is bonded and fixed via an adhesive such as resin or brazing material.

A plurality of metallized wiring layers 5 are formed on the insulating base 1 so as to extend from the stepped periphery of the concave portion 1a to the outside of the container 3. The metallized wiring layer 5 has a stepped peripheral portion of the concave portion 1a. Each electrode of the semiconductor integrated circuit device 4 is electrically connected via a bonding wire 6 and
An external lead terminal 7 connected to an external electric circuit is attached to a portion led out of 3 through a brazing material 8 such as silver brazing.

The insulating substrate 1 is made of, for example, an electrically insulating material such as alumina ceramics, and is made of alumina (Al ₂ O).
₃ ), silica (SiO ₂ ), magnesia (MgO), calcia
An appropriate organic solvent and a suitable organic solvent are added to the raw material powder such as (CaO) to form a slurry by adding and mixing a solvent and forming a ceramic green sheet (ceramic raw sheet) by employing a doctor blade method or a calendar roll method, Thereafter, the ceramic green sheet is manufactured by subjecting the ceramic green sheet to appropriate punching, laminating a plurality of sheets, and firing at a high temperature (about 1600 ° C.).

The metallized wiring layer 5 is made of a high melting point metal powder such as tungsten, molybdenum, manganese or the like. The metal paste obtained by adding an appropriate organic solvent or solvent to the high melting point metal powder such as tungsten is mixed. Substrate 1
The ceramic green sheet to be formed is printed and applied in a predetermined pattern by a conventionally well-known screen printing method, so that the ceramic green sheet is adhered and formed so as to be led out of the container 3 from the periphery of the stepped portion 1a of the insulating substrate 1 to the outside.

The metallized wiring layer 5 is coated on its exposed outer surface with a metal having excellent corrosion resistance such as nickel and gold and a good wettability with a brazing material by a plating method of 1.0 to 20.0 μm.
The metallized wiring layer 5 can be effectively prevented from being oxidized and corroded, and the connection between the metallized wiring layer 5 and the bonding wires 6 and the brazing between the metallized wiring layer 5 and the external lead terminals can be effectively prevented. The wear can be made very strong. Therefore, in order to prevent the metallized wiring layer 5 from being oxidized and corroded and to make the connection between the metallized wiring layer 5 and the bonding wires 6 and the brazing between the metallized wiring layer 5 and the external lead terminals 7 firm, It is preferable that nickel, gold or the like is layered on the exposed outer surface to a thickness of 1.0 to 20.0 μm.

An external lead terminal 7 attached to the metallized wiring layer 5 via a brazing material such as silver brazing serves to connect the semiconductor integrated circuit element 4 housed therein to an external electric circuit. The semiconductor integrated circuit device 4 accommodated therein by connecting the lead terminals 7 to an external electric circuit.
Are electrically connected to an external electric circuit via the metallized wiring layer 5 and the external lead terminals 7.

The external lead terminals 7 are made of a metal material such as Kovar metal (iron-nickel-cobalt alloy) or 42 alloy (iron-nickel alloy). For example, a predetermined shape is formed by employing a conventionally known metal working method.

The external lead terminal 7 is preferably formed by plating a metal having excellent corrosion resistance, such as nickel and gold, and a good wettability with a brazing material to a thickness of 1.0 to 20.0 μm on the outer surface thereof by a plating method. The oxidation corrosion of the external lead terminal 7 can be effectively prevented, and the electrical connection between the external lead terminal 7 and the external electric circuit can be made good. Therefore, the external lead terminals 7 should be coated with nickel, gold, etc.
It is preferable to coat the layer to a thickness of 1.0 to 20.0 μm.

The insulating substrate 1 further has a metal layer 9 on its upper surface.
A lid 2b is bonded to the metal layer 9 via a sealing material A, whereby the semiconductor integrated circuit element 4 is hermetically sealed in the container 3.

A metal layer deposited on the upper surface of the insulating substrate 1
9 is made of a high melting point metal powder such as tungsten, molybdenum, manganese or the like, and an organic solvent and a solvent obtained by adding and mixing the high melting point metal powder to the insulating base 1
The ceramic green sheet is printed and applied by adopting a conventionally known screen printing method, etc.
The ceramic green sheet is fired at a high temperature,
At the same time, it is adhered to the upper surface of the insulating base 1.

A layer made of nickel and a layer made of gold are sequentially formed on the surface of the metal layer 9 in order to improve the wettability with the sealing material A.

The lid 2 joined to the upper surface of the insulating base 1 is made of an electrically insulating material such as alumina ceramics, and a metal layer 10 is previously applied to the outer periphery of the lower surface thereof.
By joining the metal layer 10 to the metal layer 9 on the upper surface of the insulating base 1 via the sealing material A, the lid 2 is bonded to the insulating base 1.

The lid 2 is made of, for example, alumina (Al ₂ O
₃ ), silica (SiO ₂ ), magnesia (MgO), calcia
(CaO) A suitable organic solvent, a raw material powder obtained by adding and mixing a solvent is filled in a press mold and pressed at a constant pressure to be molded, and then, the molded article is fired at a temperature of about 1500 ° C. Produced by

The metal layer 10 attached to the outer periphery of the lower surface of the lid 2 is composed of silver-platinum of 80.0 to 98.0% by weight of silver and 2.0 to 20.0% by weight of platinum.
A metal paste obtained by adding and mixing a solvent is printed and applied to the outer peripheral portion of the lower surface of the lid 2 by a conventionally known screen printing method or the like, and then baked at a high temperature so that the outer peripheral portion of the lower surface of the lid 2 has a thickness. Deposited over 10 μm.

Since the metal layer 10 made of silver-platinum contains platinum which is hardly oxidized, almost no oxide film is formed on the surface. As a result, the metal layer 10 and the sealing material A The bonding strength of the
1 can be firmly joined via the sealing material A.

Further, the sealing material A for bonding the lid 2 to the upper surface of the insulating base 1 is composed of 2.0 to 6.0% by weight of tin and 2.0% by weight of bismuth.
To 10.0% by weight, less than 1.5% by weight of indium, less than 1.5% by weight of silver, and the balance of lead, and the sealing material A is made of the metal layers 9 and 10 adhered to the insulating base 1 and the lid 2. Both have good wettability, and the lid 2 can be firmly joined to the upper surface of the insulating base 1 to completely seal the container 3 hermetically.

The tin 2.0 to 6.0% by weight and bismuth 2.0
The encapsulant A, which is composed of an alloy of about 10.0% by weight, less than 1.5% by weight of indium, less than 1.5% by weight of silver, and less than 1.5% by weight of silver, and the balance being lead, also has a melting point of 280 ° C., which is about 10% lower than conventional solder, When the insulating base 1 and the lid 2 are joined by A, even if heat for heating and melting the sealing material A is applied to the semiconductor integrated circuit element 4 housed therein, the semiconductor integrated circuit element 4 is thermally broken. However, no thermal change is caused in the characteristics, and as a result, the semiconductor integrated circuit element 4 can be operated normally and stably for a long time.

The tin (Sn) contained in the sealing material A is
It is a component for improving the wettability of the sealing material A with respect to the metal layers 9 and 10 adhered to the insulating base 1 and the lid 2, and if the content is less than 2.0% by weight, the sealing material A Insulating substrate 1
In addition, the bonding strength between the metal layers 9 and 10 attached to the lid 2 is weakened, and the reliability of the hermetic sealing of the container 3 is greatly deteriorated. When the insulating base 1 and the lid 2 are joined to each other, the heat melting temperature of the semiconductor integrated circuit element 4 becomes high, and the semiconductor integrated circuit element 4 housed therein may cause thermal destruction or the like. Therefore, the tin (S
n) is specified in the range of 2.0 to 6.0% by weight.

The bismuth (B) contained in the sealing material A
i) is a component that lowers the heat-melting temperature of the sealing material A. If the content is less than 2.0% by weight, the heat-melting temperature of the sealing material A increases, and the insulating base 1 and the lid 2 are joined. In this case, the semiconductor integrated circuit element 4 accommodated therein causes thermal destruction and the like. If the content exceeds 10.0% by weight, a grain boundary is formed in the sealing material A, and the strength is reduced. It becomes impossible to firmly join the body 2. Therefore, the amount of bismuth contained in the sealing material A is specified in the range of 2.0 to 10.0% by weight.

Further, indium contained in the sealing material A
(In) is a component that lowers the heat melting temperature of the sealing material A. If the content exceeds 1.5% by weight, the oxidation of the sealing material A is accelerated, and the thermal shock resistance of the sealing material A is deteriorated. Content is specified to be less than 1.5% by weight.

Further, silver (Ag) contained in the sealing material A
Is a component for improving the wettability of the sealing material A with respect to the metal layers 9 and 10 adhered to the insulating base 1 and the lid 2 and for improving the bonding strength. The content is 1.5% by weight. If it exceeds, the sealing material A becomes poor in wettability with respect to the metal layer 10 adhered to the lid 2, and the lid 2 is placed on the insulating substrate 1.
Since it becomes impossible to make a strong connection via A and the reliability of hermetic sealing of the container 3 is greatly deteriorated, its content is specified to be less than 1.5% by weight.

The sealing material A is previously bonded to a metal layer 10 attached to the lid 2 in order to facilitate the workability of bonding between the insulating base 1 and the lid 2. The joining of the material A to the metal layer 10 adhered to the cover 2 is performed by adding a paste obtained by adding an organic solvent and a solvent to the alloy powder constituting the sealing material A and applying the paste to the cover 2. Printing is performed on the layer 10 by a conventionally known screen printing method, and thereafter, the resultant is baked at a temperature of about 350 ° C. to melt-adhere the sealing material A to the surface of the metal layer 10.

Thus, according to the semiconductor device housing package of the present invention, the semiconductor integrated circuit device 4 is bonded and fixed to the bottom surface of the concave portion 1a of the insulating base 1 with an adhesive, and each electrode of the semiconductor integrated circuit device 4 is metallized wiring layer. 5 via a bonding wire 6, and then a lid 2 is joined to the upper surface of the insulating base 1 with a sealing material A,
A semiconductor device as a product is completed by hermetically enclosing the semiconductor integrated circuit element 4 inside 3.

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 metal deposited on the upper surface of the insulating substrate 1 can be modified. Metal layer with layer 9 applied to the outer periphery of the lower surface of lid 2
It may be formed of the same material as 10.

[0033]

According to the package for accommodating a semiconductor element of the present invention, since at least the metal layer attached to the lid is formed of silver-platinum, an oxide film is formed on the surface of the metal layer. As a result, the bonding strength between the metal layer of the lid and the sealing material is increased, and thus the lid can be firmly bonded to the insulating base via the sealing material.

The sealing material may be composed of an alloy of tin 2.0 to 6.0% by weight, bismuth 2.0 to 10.0% by weight, indium less than 1.5% by weight, silver less than 1.5% by weight, and the balance of lead. When the metal layer adhered to the insulating base and the metal layer adhered to the lid are joined via a sealing material, the metal Even if heat for heating and melting the stopper material is applied to the semiconductor integrated circuit element housed therein, the semiconductor integrated circuit element hardly causes thermal destruction or changes in characteristics, and as a result, the semiconductor integrated circuit The element can be operated normally and stably for a long period of time.

[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 ... Lid 3 ... Container 4 ... Semiconductor integrated circuit element 5 ... Metallized wiring layer 7 ... External lead terminal 9 ... Metal layer applied to insulating substrate 10 Metal layer applied to lid A Sealing material

Claims (1)

(57) [Claims] The semiconductor element is hermetically sealed by joining a metal layer adhered to the insulating substrate and a metal layer adhered to the lid via a sealing material. A semiconductor element storage package to be sealed in, wherein the metal layer applied to at least the lid is made of silver-platinum,
And the sealing material is tin 2.0 to 6.0% by weight, bismuth 2.0 to
10.0% by weight, indium less than 1.5% by weight, silver 1.5% by weight
A package for accommodating a semiconductor element, wherein less than and the remainder are made of a lead alloy.