JP2538845Y2 - 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 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 made of an electrically insulating material such as alumina ceramics, and has a central space for housing the semiconductor element. An insulating base having a concave portion for forming, a low-melting glass layer for sealing is adhered on the upper surface, and a cavity for accommodating a semiconductor element in the center portion also made of an electrically insulating material such as alumina ceramics. A lid having a concave portion for forming, a lower-melting glass layer for sealing attached to the lower surface, and an external lead terminal for electrically connecting a semiconductor element housed therein to an external electric circuit An external lead terminal is placed on the upper surface of the insulating base and the sealing is performed on the external lead terminal by melting the low-melting glass layer for sealing which has been applied in advance. The semiconductor element is temporarily fixed, and then a semiconductor element is attached via an adhesive to a metal layer previously layered on the bottom of the concave portion of the insulating base, and each electrode of the semiconductor element is connected to an external lead terminal via a bonding wire. After that, a low-melting glass layer for sealing, in which the insulating base and the lid are adhered to the respective main surfaces facing each other, is melted and integrated, and the insulating base and the lid are separated from each other. A semiconductor device as a product is obtained by hermetically sealing the container.

The metal layer deposited on the bottom surface of the concave portion of the insulating substrate is formed by adding a conductive paste obtained by adding a suitable organic solvent and a solvent to silver powder having an average particle size of 1.0 to 3.0 μm and mixing the conductive paste. And diffused to a uniform thickness of about 10 to 15 μm, and then fired at a temperature of about 900 ° C. to be layered on the bottom surface of the concave portion of the insulating substrate.

The adhesive for attaching the semiconductor element to the metal layer is made of a thin plate such as gold or gold-silicon eutectic solder. Then, the semiconductor element is attached to the bottom surface of the concave portion of the insulating base by heating and melting the semiconductor element.

[0005]

However, in this conventional package for housing a semiconductor element, the metal layer deposited on the bottom of the concave portion of the insulating base is made of silver, which is a metal that is easily oxidized. When a metal layer is deposited on the bottom surface of the concave portion of the insulating base, an oxide film is formed on the surface of the metal layer in a very short time, and once the oxide film is formed on the surface, the metal layer is formed. When a semiconductor element is mounted on an adhesive made of gold or gold silicon eutectic solder, etc., the bonding strength of the adhesive to the metal layer becomes extremely weak due to the oxide film on the metal layer surface. However, when an external force is applied to the semiconductor element, the semiconductor element is very easily detached from the metal layer due to the external force.

Although the metal layer made of silver is deposited on the bottom surface of the concave portion of the insulating base by baking, the bonding strength between the silver and the insulating base is very weak because the reactivity between the silver and the insulating base is very low. When the semiconductor element is attached by heating and melting the adhesive, the shape of the semiconductor element becomes large, and when the amount of the adhesive increases, the metal layer peels off from the insulating base together with the semiconductor element due to the tensile force of the adhesive. Had the disadvantage that

[0007]

According to the present invention, there is provided a semiconductor device housing package comprising a cover and an insulating base having a recess for housing a semiconductor element. A metal layer containing at least 1.0% by weight and at least 0.2% by weight of platinum.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows an embodiment of a package for accommodating a semiconductor device according to the present invention, wherein 1 is an insulating base made of an electrically insulating material such as alumina ceramics, and 2 is a lid made of the same electrically insulating material. The semiconductor element 3 is formed by the insulating base 1 and the lid 2.
Is configured.

The insulating base 1 and the lid 2 are provided with a concave portion for forming a space for accommodating the semiconductor element 3 at the center thereof, and a metal layer is formed on the bottom of the concave portion 1a of the insulating base 1.
4 is layered.

The insulating substrate 1 and the lid 2 are formed by employing a conventionally known press molding method. For example, when the insulating substrate 1 and the lid 2 are made of alumina ceramic, the insulating substrate 1 and the lid 2 are formed as shown in FIG. The raw material powder of alumina ceramics is filled in a mold having the shape corresponding to 1 or lid 2 and molded by applying a certain pressure, and then the molded product is fired at a temperature of about 1500 ° C. Is done.

The metal layer 4 layered on the bottom surface of the concave portion 1a of the insulating base 1 has a silver content of 0.3 to 1.0% by weight of copper and platinum.
The metal layer 4 serves as a base metal when the semiconductor element 3 is attached to the bottom surface of the concave portion 1a of the insulating substrate 1, and the semiconductor element 3 is formed on the metal layer 4. Is attached via an adhesive 5 such as gold-silicon eutectic solder.

The metal layer 4 is formed by adding copper powder to silver powder in an amount of 0.3 to 0.3.
1.0 wt% and platinum are added in an amount of 0.2 wt% or more, and an organic solvent and a solvent are further added and mixed to obtain a conductive paste. After spreading to thickness, about 950
By firing at a temperature as high as
It is attached to the bottom.

The metal layer 4 contains 0.3 to 1.
When the conductive paste is dropped onto the bottom surface of the concave portion 1a of the insulating substrate 1 and fired at a high temperature to deposit the metal layer 4 on the bottom surface of the insulating substrate 1, the interface between the concave portion 1a of the insulating substrate 1 and the metal layer 4 is contained. In this case, a reaction layer having a spinel structure of copper oxide and alumina is formed, and the adhesion strength of the metal layer 4 to the insulating base 1 becomes extremely strong. Therefore, when the semiconductor element 3 is attached to the metal layer 4 by heating and melting the adhesive 5, the shape of the semiconductor element 3 becomes large, the amount of the adhesive 5 increases, and the metal layer formed by the adhesive 5 becomes large.
Even if the tensile force of 4 becomes large, the metal layer 4
Does not peel off from the insulating substrate 1 together with the semiconductor element 3, and the semiconductor element 3 can be firmly attached to the bottom surface of the concave portion 1 a of the insulating substrate 1.

If the content of copper contained in the metal layer 4 is less than 0.3% by weight, a reaction layer (copper oxide and alumina) formed at the interface between the metal layer 4 and the bottom surface of the concave portion 1a of the insulating substrate 1 is formed. The reaction layer having a spinel structure), the metal layer 4 cannot be firmly deposited on the bottom surface of the concave portion 1a of the insulating base 1, and if the copper content exceeds 1.0% by weight, the metal layer 4 Deposits on the surface of the semiconductor layer on the metal layer 4
3 cannot be firmly attached. Therefore, the content of copper contained in the metal layer 4 is specified in the range of 0.3 to 1.0% by weight.

The metal layer 4 contains 0.2% by weight or more of platinum, and the platinum has an effect of effectively preventing the surface of the metal layer 4 from being oxidized.

An oxide film is hardly formed on the surface of the metal layer 4 containing platinum by the action of the platinum. As a result, the semiconductor element 3 is melted on the metal layer 4 by heating the adhesive 5. By doing so, it is possible to join the metal layer 4 and the adhesive layer 5 with high joining strength,
The semiconductor element 3 can be firmly attached on the metal layer 4.

If the content of platinum contained in the metal layer 4 is less than 0.2% by weight, an oxide film is formed on the surface of the metal layer 4 in a short time, and the semiconductor element 3 is formed on the metal layer 4. It cannot be firmly attached. Therefore, the content of platinum contained in the metal layer 4 is specified to be 0.2% by weight or more,
Considering the cost of the product, the content is preferably in the range of 0.2 to 2.0% by weight.

If the particle size of copper and platinum contained in the metal layer 4 is set to about 10 to 30% with respect to the particle size of silver, copper and platinum are uniformly dispersed between silver powder particles, As a result, the metal layer 4 can be more firmly deposited on the bottom surface of the concave portion 1a of the insulating base 1, and the formation of an oxide film on the surface of the metal layer 4 can be more effectively prevented.

The metal layer 4 further comprises a semiconductor element 3 to be attached.
When the bottom area of the concave portion 1a provided in the insulating base 1 is 80 mm ² or more, the semiconductor element 3 is insulated if the thickness is set to 25 μm or more when the size of the concave portion 1a is as large as about 6.0 mm × 8.0 mm. Metal layer 4 adhered to the bottom of concave portion 1a of base 1
When the metal layer 4 is attached via the adhesive 5, the metal layer 4 absorbs the thermal stress caused by the difference in the coefficient of thermal expansion between the semiconductor element 3 and the insulating base 1 by deforming the metal layer 4. However, it is possible to effectively prevent the semiconductor element 3 from being cracked or broken due to thermal stress generated between the semiconductor element 3 and the insulating base 1. Therefore, the metal layer 4 has a large dimension of the semiconductor element 3 to be attached, which is about 6.0 mm × 8.0 mm, and the bottom area of the concave portion 1 a provided in the insulating base 1 is 80 mm.
When the thickness is ² or more, it is preferable to set the thickness to 25 μm or more.

Further, when the metal layer 4 is made to have a crystal grain size of 7.0 to 14.0 μm by slightly increasing the crystal grain size of silver constituting the metal layer to a firing temperature of about 950 ° C., the gap between silver crystals is reduced, and The surface roughness of the metal layer 4 becomes smooth with a center line average roughness Ra of about Ra = 0.55 μm,
As a result, the semiconductor element 3 is placed on the metal layer 4 via the adhesive 5.
When attaching, the spread of the adhesive 5 on the metal layer 4 becomes extremely good, and the semiconductor element 3 can be attached to the metal layer 4 very firmly. Therefore, it is preferable that the metal layer 4 has a crystal grain size of silver constituting it of 7.0 to 14.0 μm.

The insulating base 1 and the lid 2 are also provided with sealing low-melting glass layers 6a and 6b on their opposing main surfaces in advance. The insulating low-melting glass layers 6a and 6b attached to each of 2 are heated and melted and integrated to form the insulating base 1 and the lid.
The semiconductor element 3 is hermetically sealed in the container formed by the steps 2 and 3. The sealing low-melting glass layers 6a and 6b that are adhered to the opposing main surfaces of the insulating base 1 and the lid 2 are made of, for example, lead oxide.
A glass paste obtained by adding a suitable organic solvent and a solvent to the glass powder and mixing the glass paste with a glass paste of 75.0% by weight, 9.0% by weight of titanium oxide, 7.5% by weight of boron oxide, and 2.0% by weight of zinc oxide. By employing a thick film technique such as screen printing, the insulating substrate 1 and the lid 2 are attached to the opposing main surfaces of the cover 2 and the lid 2, respectively.

If the thermal expansion coefficients of the low melting glass layers 6a and 6b for sealing are set to values close to the thermal expansion coefficients of the insulating base 1 and the lid 2, the insulating base 1, the lid 2 When the container is air-tightly sealed through the low melting point glass layers 6a and 6b for sealing, the insulating base 1 and the lid 2 and the low melting point glass layers 6a and 6b Almost no thermal stress occurs due to the difference in thermal expansion coefficient between the insulating base 1 and the lid 2.
Can be firmly joined via the low-melting glass layers 6a and 6b for sealing. Therefore, the sealing low melting point glass layer 6a,
It is preferable that the thermal expansion coefficient of 6b is adjusted to the thermal expansion coefficients of the insulating base 1 and the lid 2.

A conductive material such as Kovar (Fe--Ni--C alloy) or 42 alloy (F) is provided between the insulating base 1 and the lid 2.
An external lead terminal 7 made of a metal such as e-Ni alloy) is provided, and the external lead terminal 7 is electrically connected to each electrode of the semiconductor element 3 via a bonding wire 8. By connecting to the external electric circuit, the semiconductor element 3 is connected to the external electric circuit.

The external lead terminals 7 are simultaneously sealed with the insulating base 1 when the container comprising the insulating base 1 and the lid 2 is hermetically sealed by melting and integrating the low-melting glass layers 6a and 6b for sealing. It is attached and fixed between the lids 2.

The external lead terminal 7 has a good conductivity such as nickel, gold or the like on its outer surface in order to improve the electrical continuity with an external electric circuit and to effectively prevent oxidation and corrosion. 1.0 to 20.0 of metal with excellent corrosion resistance
It is preferable that the layer is deposited by plating to a thickness of μm.

Thus, according to the semiconductor device housing package, the semiconductor device 3 is mounted on the metal layer 4 on the bottom surface of the concave portion 1a provided on the insulating base 1 via the adhesive 5 made of gold, gold silicon eutectic solder or the like. Attach and fix the semiconductor element 3
External terminals with bonding wires 8
7, and then the insulating base 1 and the lid 2 are fused and integrated with the sealing low-melting glass layers 6a and 6b, which are previously adhered to the opposing main surfaces thereof. Upon joining, the semiconductor element 3 is hermetically sealed inside a container formed of an insulating base and a lid, and a semiconductor device as a final 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. In addition to a glass-sealed semiconductor element storage package that hermetically seals a container made of It is possible.

[0028]

According to the package for housing a semiconductor element of the present invention, a metal comprising 0.3 to 1.0% by weight of copper and 0.2% by weight or more of platinum in silver on the bottom surface of a concave portion of an insulating base constituting a package container. When the metal layer is layered on the bottom of the concave portion of the insulating substrate, the strength of the layering is extremely increased and the oxide film is effectively prevented from being formed on the surface of the metal layer. The semiconductor element can be very firmly attached on the metal layer.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an embodiment of a package for housing a semiconductor device according to the present invention;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Insulating base 1a ... Depression 2 ... Lid 3 ... Semiconductor element 4 ... Metal layer 5 ... Adhesive 7 ... External lead terminal

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-121731 (JP, A) JP-A-2-238640 (JP, A) JP-A-3-19246 (JP, A) JP-A-63-1988 229843 (JP, A) JP-A-63-54755 (JP, A) JP-A-2-7534 (JP, A) JP-A-4-323385 (JP, A) JP-A-56-167339 (JP, A) JP-A-61-150352 (JP, A) JP-A-60-189954 (JP, A)

Claims (1)

(57) [Scope of request for utility model registration] 1. A semiconductor device housing package comprising a cover and an insulating base having a recess for housing a semiconductor element, wherein 0.3 to 1.0% by weight of copper and platinum are coated on the bottom of the recess of the insulating base. A package for accommodating a semiconductor element, wherein a metal layer containing 0.2% by weight or more is deposited.