JP2746802B2 - Semiconductor device - 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 having a semiconductor element housed in a semiconductor element housing package.

[0002]

2. Description of the Related Art Conventionally, a semiconductor device in which a semiconductor element is hermetically housed in a semiconductor element housing package is used for an information processing apparatus such as a computer.

As shown in FIGS. 3 and 4, a semiconductor device used in such an information processing apparatus is usually made of an electrically insulating material such as alumina ceramics, and has a concave portion for accommodating a semiconductor element 20 in the center of the upper surface. An insulating base 21 having a plurality of metallized wiring layers 22 extending from the periphery of the recess 21a to the outer peripheral edge; and the metallized wiring layer 22 for electrically connecting the semiconductor element 20 to an external electric circuit.
External lead terminals 23 attached through a brazing material such as silver brazing
And a lid 24, a semiconductor element housing package is prepared, and the semiconductor element is adhered and fixed to the bottom surface of the concave portion 21a of the insulating base 21 via an adhesive 25 such as glass or resin, and the respective electrodes of the semiconductor element 20 are also fixed. Is connected to the metallized wiring layer 22 via bonding wires 26, and then a lid 24 is bonded to the upper surface of the insulating base 21 via a sealing material, and the semiconductor is placed inside the container formed of the insulating base 21 and the lid 24. A semiconductor device is obtained by housing the element 20 in an airtight manner.

Incidentally, the bonding and fixing of the semiconductor element 20 to the bottom surface of the concave portion 21a of the insulating base 21 is generally performed by first adding a suitable organic solvent and a solvent to glass powder when glass is used as the adhesive 25. The glass paste is applied to the concave portion 21 of the insulating base 21.
a Apply to the bottom surface, then place the semiconductor element 20 on the glass paste and heat the glass paste at a temperature of about 450 ° C. to disperse the organic solvent and the solvent in the glass paste and melt the glass powder. This is done by:

[0005]

However, recently,
Semiconductor devices have rapidly increased in density and integration, and have become extremely large in shape. When the semiconductor device is housed in a conventional semiconductor device housing package, the semiconductor device has an area of 90% of the area of the bottom of the concave portion of the insulating base. %, And the gap between the side wall of the concave portion and the side surface of the semiconductor element has become extremely narrow. Therefore, when the semiconductor element is adhered and fixed to the bottom surface of the insulating base recess of the package for semiconductor element storage using, for example, an adhesive made of glass, the organic solvent and the solvent contained in the glass paste are removed from the side wall of the recess of the insulating base and the semiconductor element. Due to the small distance between the side surfaces of the semiconductor device, the semiconductor device is not scattered well and is included in the adhesive. As a result, the adhesive strength of the semiconductor element to the bottom surface of the concave portion of the insulating substrate becomes extremely weak, and the semiconductor device is easily squeezed by the application of external force. It had the disadvantage of coming off.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and has as its object to firmly adhere and fix a semiconductor element to the bottom surface of a concave portion of an insulating substrate of a package for housing a semiconductor element so that the semiconductor element can be normally used for a long time. Another object of the present invention is to provide a semiconductor device that can be operated stably.

[0007]

According to the present invention, there is provided a semiconductor device comprising an insulating base having a concave portion on the surface, a semiconductor element housed in the concave portion, and a lid for closing the concave portion. Is characterized in that the area S _{1 of the} bottom surface of the recess is S ₂ ≧ 0.9S ₁ with respect to the plane area S _{2 of the} semiconductor element, and at least one notch is formed in the side wall of the recess. .

[0008]

According to the semiconductor device of the present invention, the size of the semiconductor element occupies 90% or more of the area of the bottom surface of the recess because the notch is formed in the side wall of the recess of the insulating base for housing the semiconductor element. Even if this occurs, a wide gap can be formed between the side wall of the concave portion and the side surface of the semiconductor element. As a result, when the semiconductor element is bonded and fixed to the bottom surface of the concave portion of the insulating base via an adhesive, the semiconductor element is released from the adhesive. The organic solvent and the solvent are satisfactorily radiated to the outside through the gap, and are hardly included in the adhesive. This makes it possible to bond and fix the semiconductor element to the bottom surface of the concave portion of the insulating base very strongly. Become.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 and 2 show one embodiment of the semiconductor device of the present invention, wherein 1 is an insulating base, 2 is a lid, and 3 is a semiconductor element.

The insulating substrate 1 is made of an electrically insulating material such as an aluminum oxide sintered body, a mullite sintered body, a silicon carbide sintered body, an aluminum nitride sintered body, a glass-ceramic sintered body, etc. A concave portion 1a for forming a space for accommodating the semiconductor element 3 is formed in the center of the upper surface.

When the insulating substrate 1 is made of, for example, an aluminum oxide sintered body, it is suitable for a raw material powder such as alumina (Al ₂ O ₃ ), silica (SiO ₂ ), calcia (CaO), and magnesia (MgO). An organic solvent, a solvent is added and mixed to form a slurry, and a ceramic green sheet (ceramic green sheet) is obtained by adopting a conventionally known doctor blade method, calender roll method, or the like. In addition to performing appropriate punching processing, and laminating a plurality of these, high temperature (about 1600
(° C).

A semiconductor element 3 is fixed to the bottom of the recess 1a formed in the insulating base 1 via an adhesive 4 such as glass, resin or the like.
Is accommodated.

For example, when the adhesive 4 is made of glass, an organic solvent suitable for a glass powder containing 70 to 90% by weight of silver powder is used for bonding and fixing the semiconductor element 3 to the bottom surface of the concave portion 1a of the insulating base 1. A solvent is added and mixed to form a glass paste, and then the glass paste is applied to the bottom surface of the concave portion 1a of the insulating substrate 1 to a predetermined thickness, and the semiconductor element 3 is placed on the glass paste. The paste is heated at a temperature of about 450 ° C. to disperse the organic solvent and the solvent in the glass paste to the outside and heat and melt the glass powder.

The insulating substrate 1 has a plurality of cutouts 1b formed on the side wall of the concave portion 1a, and the cutout portion 1b is formed in the concave portion 1a of the insulating base 1. The size is 90 with respect to the area of the bottom of the concave portion 1a.
% Or more, a large gap is formed between the side wall of the concave portion 1a and the side surface of the semiconductor element 3, whereby the semiconductor element 3 is separated from the concave portion 1a of the insulating base 1.
When the organic solvent and the solvent are released from the adhesive 4 when the adhesive is fixed to the bottom surface with the adhesive 4, the organic solvent and the like are satisfactorily radiated to the outside through the gap and included in the adhesive 4. As a result, the semiconductor element 3 can be extremely firmly bonded and fixed to the bottom surface of the concave portion 1a of the insulating base 1.

The notch 1b on the side wall of the recess 1a is formed by laminating and firing a plurality of ceramic green sheets.
When the substrate is obtained, a notch is formed in advance at a position corresponding to the concave side wall of each ceramic green sheet by a punching method, so that a predetermined shape is formed on the side wall of the concave portion 1a of the insulating base 1.

A plurality of metallized wiring layers 5 are formed on the insulating substrate 1 from the periphery of the concave portion 1a to the outer peripheral edge thereof. Each electrode of the semiconductor element 3 is provided around the concave portion 1a 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 provided at portions led out to the outer peripheral edge of the insulating base 1.
Is attached via a brazing material such as silver brazing.

The metallized wiring layer 5 is made of tungsten,
A metal paste obtained by adding a suitable organic solvent and a solvent to the high melting point metal powder, such as molybdenum, manganese, etc., is applied to the metal paste by using a conventionally known thick film method such as a screen printing method. By printing and applying a predetermined pattern on a ceramic green sheet serving as the base 1 in advance, the insulating green base 1 is adhered and formed from the periphery of the concave portion 1a to the outer peripheral edge.

The metallized wiring layer 5 is formed by plating a metal having excellent corrosion resistance such as nickel and gold and having good conductivity with a thickness of 1.0 to 20.0 μm on the exposed surface by plating. The wiring layer 5 can be effectively prevented from being oxidized and corroded, and the metallized wiring layer 5 can be prevented.
Between metallization and bonding wire 6 and metallized wiring layer
The soldering of the external lead terminal 7 to the terminal 5 can be made firm. Therefore, the metallized wiring layer 5 is effectively prevented from being oxidized and corroded, and the metallized wiring layer 5 is
Connection with bonding wire 6, metallized wiring layer 5
In order to strengthen the brazing between the metallization wiring layer 5 and the external lead terminal 7, a metal having excellent corrosion resistance such as nickel or gold and a good conductive metal is plated on the exposed surface of the metallized wiring layer 5 by 0.1 to 2 mm.
It is preferable to coat the layer to a thickness of 0.0 μm.

External lead terminals 7 are attached to the metallized wiring layer 5 via a brazing material such as silver brazing.
The external lead terminal 7 functions to electrically connect the semiconductor element 3 housed therein to an external electric circuit, and the semiconductor element 3 housed inside by connecting the external lead terminal 7 to an external electric circuit is formed. It is 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 Kovar metal (iron-nickel-cobalt alloy), 42 alloy (iron-nickel alloy), or the like.
The (mass) is formed into a predetermined plate shape by employing a conventionally known metal working method such as a rolling method or a punching method.

Further, the insulating substrate 1 has a lid 2 on its upper surface.
Are bonded via a sealing material such as glass or resin so as to cover the concave portion 1a of the insulating base 1, and the semiconductor element 3 is hermetically housed inside a container formed of the insulating base 1 and the lid 2 to form a product. Semiconductor device.

A lid 2 joined to the upper surface of the insulating base 1
Is made of an electrical insulating material such as an aluminum oxide sintered body or a metal material such as Kovar metal.
Acts to seal airtightly.

Thus, in the semiconductor device of the present invention, the external lead terminal 7 is connected to the external electric circuit, and the internal semiconductor element 3
Is connected to an external electric circuit to be mounted on an information processing apparatus such as a computer.

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. Although the semiconductor element 3 is bonded and fixed to the bottom surface of the substrate 1a with an adhesive 4 made of glass, the present invention can be applied to a case where an adhesive made of a resin such as an epoxy resin containing silver powder is used.

[0025]

According to the semiconductor device of the present invention, since the notch is formed in the side wall of the concave portion of the insulating base for accommodating the semiconductor element, the size of the semiconductor element is 90% of the flat area of the bottom surface of the concave portion.
%, A wide gap can be formed between the side wall of the recess and the side surface of the semiconductor element even when the semiconductor element becomes large. As a result, the semiconductor element is bonded and fixed to the bottom of the recess of the insulating base via an adhesive. When doing, the organic solvent released from the adhesive, the solvent is satisfactorily diffused to the outside through the gap,
It is hardly included in the adhesive, which allows the semiconductor element to be extremely firmly bonded and fixed to the bottom of the concave portion of the insulating base.

Therefore, in the semiconductor device of the present invention, since the semiconductor element is firmly adhered and fixed to the bottom of the concave portion of the insulating base, the semiconductor element is separated from the bottom of the concave portion of the insulating base even when an external force is applied to the semiconductor element. And the semiconductor element can be operated normally and stably for a long period of time.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a semiconductor device of the present invention.

FIG. 2 is an enlarged plan view of a main part of the semiconductor device shown in FIG.

FIG. 3 is a cross-sectional view of a conventional semiconductor device.

FIG. 4 is an enlarged plan view of a main part of the semiconductor device shown in FIG. 3;

[Explanation of symbols]

 1 ... Insulating base 1a ... Recess 1b ... Notch 2 ... Lid 3 ... Semiconductor element 4 ... Adhesive

Claims (1)

(57) [Claims] 1. A semiconductor device comprising: an insulating base having a concave portion on its surface; a semiconductor element housed in the concave portion; and a lid for closing the concave portion, wherein the insulating base has an area S of a bottom surface of the concave portion. S ₂ ≧ ₁ Whereas plane area S ₂ of the semiconductor element
It is 0.9 S _1, and the recess sidewall, the bottom surface of the recess
A semiconductor device, wherein at least one notch communicating with the upper surface is formed.