JPH0745962Y2 - Package for storing semiconductor devices - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an improvement of a semiconductor element housing package for housing a semiconductor element.

(Prior Art) Conventionally, semiconductor element housing packages for housing semiconductor elements such as LSIs (Large Scale Integrated Circuits) are shown in FIGS.
As shown in the figure, it is made of an electrically insulating material such as alumina ceramics and has a concave portion for accommodating a semiconductor element on the upper surface and molybdenum (M
o), tungsten (W), manganese (Mn), etc. Insulating substrate having metallized metal layer 12 made of high melting point metal powder
11, an external lead terminal 13 and a lid 14 which are attached to the metallized metal layer 12 via a brazing material such as silver brazing (Ag-Cu alloy) for electrically connecting the semiconductor element to an external circuit. The semiconductor element 15 is formed on the bottom surface of the recess of the insulating base 11.
Are fixed and attached using gold-silicon (Au-Si) eutectic solder or silver (Ag) -based epoxy adhesive, etc., and each electrode of the semiconductor element 15 is electrically connected to the metallized metal layer 12 via the bonding wire 16. At the same time, the lid 14 is bonded to the upper surface of the insulating base 11 via the sealing material 17 such as glass or resin, and the semiconductor element 15 is hermetically sealed in the recess of the insulating base 11 to form a semiconductor device. .

In such a conventional package for accommodating semiconductor elements, an insulating substrate is usually manufactured by the following method.

That is, first, an appropriate organic solvent and a solvent are added to and mixed with a raw material powder such as alumina (Al ₂ O ₃ ) ceramic to form a slurry,
The sludge is formed into a sheet by adopting a doctor blade method to obtain a plurality of ceramic green sheets (green sheets). Next, the ceramic green sheets are provided with holes of a predetermined shape and tungsten ( W), molybdenum (Mo), manganese (Mn) and other high melting point metal powders are applied by a screen printing method in a predetermined pattern by printing, and finally a plurality of the ceramic green sheets are laminated to form a ceramic green sheet. At the same time as obtaining the laminated body, the laminated body is fired at a temperature of about 1500 ° C. in a reducing atmosphere to sinter and integrate the respective ceramic green sheets and the metal paste, thereby forming an insulating substrate.

(Problems to be solved by the invention) However, in the conventional semiconductor element housing package, the insulating base is manufactured by using the ceramic green sheet, and the sludge of the ceramic raw material is adopted by the doctor blade method. The center line average roughness (Ra) of the surface of the ceramic green sheet formed into a sheet by this is small as Ra ≦ 0.5 μm, and the insulating substrate obtained by laminating a plurality of the ceramic green sheets also has a center line of the surface. The average roughness (Ra) becomes Ra ≦ 0.5 μm and is extremely smooth. Therefore, when the lid is joined to this insulating substrate via a sealing material such as glass or resin to hermetically seal the concave portion of the insulating substrate, the insulating substrate and the sealing material are smooth because the surface of the insulating substrate is smooth. If the heat generated during the operation of the semiconductor element is repeatedly applied between the insulating base and the sealing material due to the weak bonding strength between the insulating base and the sealing base, peeling occurs between the insulating base and the encapsulant. There is a drawback that the tight sealing is broken and the semiconductor element housed in the recess cannot be operated normally and stably for a long period of time.

Therefore, in order to eliminate the above-mentioned drawbacks, the surface of the insulating substrate is roughened by sandblasting or etching to increase the bonding area between the insulating substrate and the sealing material to increase the bonding strength between the insulating substrate and the sealing material. It can be improved.

However, when the surface of the insulating substrate is subjected to sandblasting or etching, the exposed surface of the metallized metal layer deposited on the insulating substrate is not only a rough surface but also the surface to which the sealing material of the insulating substrate is bonded. As a result, it becomes impossible to firmly bond the bonding wire to the metallized metal layer, which causes a drawback that each electrode of the semiconductor element cannot be reliably connected to a predetermined external lead terminal.

(Purpose of the Invention) The present invention has been devised in view of the above-mentioned drawbacks, and the purpose thereof is to significantly improve the bonding strength between the insulating base and the sealing material, and firmly attach the insulating base and the lid. Thus, the present invention provides a package for accommodating a semiconductor element in which the recess provided in the insulating base is completely hermetically sealed and the semiconductor element accommodated therein can be normally and stably operated for a long period of time.

(Means for Solving the Problems) The present invention comprises an insulating base having a recess for accommodating a semiconductor element and a lid, and a lid encapsulating material on the insulating base so as to close the recess of the insulating base. In the package for accommodating a semiconductor element adapted to be attached via a sealant, the surface of the insulating base on which the sealing material is bonded has substantially the same coefficient of thermal expansion as the insulating base, and the center line average roughness of the surface is Sa (Ra) is Ra ≧
It is characterized in that an insulating film formed by a thick film forming technique of 0.65 μm is deposited.

(Embodiment) Next, the present invention will be described in detail based on an embodiment shown in the accompanying drawings.

1 and 2 show an embodiment of a package for housing a semiconductor device of the present invention, 1 is an insulating base made of an electrically insulating material such as alumina ceramic, and 2 is a lid made of the same electrically insulating material. is there. The insulating base 1 and the lid 2 constitute an insulating container for housing a semiconductor element.

The insulating base 1 is provided with a stepped recess 1a for accommodating a semiconductor element in the center of the upper surface thereof, and the semiconductor element 3 is provided on the bottom surface of the recess 1a with a gold-silicon (Au-Si) eutectic solder or silver. (A
g) Attached via an adhesive such as epoxy adhesive.

The insulating substrate 1 is made into a slurry by adding an appropriate organic solvent or solvent to raw material powder such as alumina ceramics, and a ceramic green sheet (ceramic green sheet) is formed by adopting the doctor blade method. After that, the ceramic green sheets are punched appropriately, and a plurality of them are laminated at a high temperature (about
It is manufactured by firing at 1500 ℃.

A metallized metal layer 4 is formed on the insulating substrate 1 so as to extend from the stepped upper surface of the recess 1a to the side surface. The electrode of the semiconductor element 3 is bonded to the recessed portion 1a of the metallized metal layer 4 on the stepped upper surface. An external lead terminal 6 electrically connected through a wire 5 and connected to an external circuit is provided on the side surface of the insulating base 1 of the metallized metal layer 4 with silver solder (Ag-C).
u alloy) or other brazing material.

The metallized metal layer 4 is made of a refractory metal powder such as tungsten (W), molybdenum (Mo), manganese (Mn) or the like. 1a Stepped step Adhesion is formed from the upper surface to the side surface.

The external lead terminals 6 attached to the metallized metal layer 4 on the side surface of the insulating substrate 1 serve to connect the semiconductor element 3 housed inside to an external circuit, and electrically connect the external lead terminals 6 to the external circuit. As a result, the semiconductor element 3 housed inside the metallized metal layer 4 and the external lead terminals 6
It will be electrically connected to an external circuit via.

The external lead terminal 6 is made of Kovar (Fe-Ni-Co alloy) or 42
It is made of a metal such as an alloy (Fe-Ni alloy), and is formed into a predetermined plate-like shape by a conventionally known metal processing method.

In addition, nickel (Ni) is formed on the outer surface of the external lead terminal 6 in order to improve the electrical connection between the external lead terminal 6 and an external circuit and to prevent the external lead terminal 6 from being oxidized and corroded. ), Gold (Au), or the like, which has a good conductivity and is excellent in corrosion resistance, is deposited by a conventionally known plating method.

The insulating substrate 1 has a coefficient of thermal expansion substantially the same as that of the insulating substrate 1 on its upper surface, and the center line average roughness (R
In a), the insulating film 7 formed by the thick film forming technique with Ra ≧ 0.65 μm is deposited.

The insulating film 7 is applied onto the insulating base 1 by printing a sludge obtained by adding and mixing an alumina ceramic powder, which is the same material as the insulating base 1, with an appropriate organic solvent and a solvent by a thick film method such as screen printing. Then, after that, it is deposited on the insulating substrate 1 by firing at high temperature in a reducing atmosphere.

Since the insulating film 7 is formed by the thick film forming technique, it is firmly bonded onto the insulating substrate 1, and at the same time, the center line average roughness (Ra) of its surface is set to be Ra ≧ 0.65 μm. When the lid body 2 is attached to the insulating base 1 via the sealing material, the insulating base 1 and the sealing material have a large bonding area and are firmly bonded to each other. It becomes possible to attach the lid body 2 extremely firmly.

The center line average roughness (Ra) of the surface of the insulating film 7 is Ra <
When the thickness is 0.65 μm, the surface of the insulating film 7 becomes smooth, and it becomes difficult to firmly attach the lid 2 onto the insulating film 7 as in the case of the conventional semiconductor element housing package. The average roughness (Ra) is specified as Ra ≧ 0.65 μm.

Further, since the insulating film 7 is made of the same material as the insulating substrate 1, the insulating substrate 1 and the insulating film 7 have the same coefficient of thermal expansion, and even if heat generated by the semiconductor element 3 or the like is applied to them. No large thermal stress is generated between them, and the insulating film 7 is not separated from the insulating substrate 1 by the thermal stress.

The insulating film 7 does not have to be made of the same material as the insulating substrate 1 as long as it has a thermal expansion coefficient similar to that of the insulating substrate 1 so that thermal stress does not occur between the insulating substrate 1 and the insulating substrate 1. Any material may be used.

The lid 2 is attached to the upper surface of the insulating substrate 1 via the sealing material 8, whereby the inside of the recess 1a of the insulating substrate 1 is hermetically sealed.

The lid 2 is made of, for example, an electrically insulating material such as alumina ceramics, and alumina ceramic powder is formed into a flat plate shape by adopting a conventionally known press forming method, and is baked at a temperature of about 1600 ° C. Formed by.

The lid 2 has a lower surface to which a sealing material 8 is applied in advance. The sealing material 8 joins the insulating base 1 and the lid 2 to hermetically seal the recess 1a provided in the insulating base. Make the action. The sealing material 8 is made of a material obtained by adding and mixing an organic solvent and a solvent to an epoxy resin or a low melting point glass powder, and by adopting a conventionally known thick film technique such as screen printing, the lid body 2 is formed.
Is attached to the lower surface of.

Thus, the semiconductor element 3 is attached to the bottom surface of the concave portion 1a of the insulating substrate 1 with an adhesive agent, and each electrode of the semiconductor element 3 is electrically connected to the metallized metal layer 4 via the bonding wire 5, and thereafter, The lid 2 is attached to the upper surface of the insulating base 1 with a sealing material 7 such as glass or resin, and the recess 1a of the insulating base 1 is closed to complete the semiconductor device as a final product.

(Effects of the Invention) According to the package for housing a semiconductor device of the present invention, the surface of the insulating substrate on which the encapsulant is bonded has substantially the same coefficient of thermal expansion as the insulating substrate, and the center line average roughness of the surface. (Ra) is Ra
Since the insulating film formed by the thick film forming technique of ≧ 0.65 μm is applied, the bonding strength between the insulating base and the sealing material can be improved when the lid is mounted on the insulating base via the sealing material. It can be made extremely strong, and even if heat generated during operation of the semiconductor element is repeatedly applied between the insulating substrate and the sealing material, no peeling occurs between the two, and as a result, By completely hermetically sealing the recess provided in the insulating base, the semiconductor element housed in the recess can be normally and stably operated for a long period of time.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a semiconductor device housing package of the present invention, FIG. 2 is a plan view of an insulating substrate of the semiconductor device housing package shown in FIG. 1, and FIG. 3 is a conventional semiconductor device. FIG. 4 is a sectional view of the storage package, and FIG. 4 is a plan view of the insulating base of the package shown in FIG. 1: Insulating substrate, 1a: Recessed part 2: Lid, 4: Metallized metal layer 6: External lead terminal, 7: Insulating film 8: Sealing material

Claims (1)

[Scope of utility model registration request] 1. An insulating base having a recess for accommodating a semiconductor element and a lid, wherein the lid is attached to the insulating base via a sealing material so as to close the recess of the insulating base. In the package for accommodating a semiconductor element, at least the surface of the insulating substrate to which the sealing material is bonded has a coefficient of thermal expansion substantially the same as that of the insulating substrate, and the center line average of the surface formed by the thick film forming technique. A package for accommodating a semiconductor element, characterized in that an insulating film having a roughness (Ra) of Ra ≧ 0.65 μm is applied.