JP2570765Y2 - 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 package for accommodating a semiconductor device, in particular, a semiconductor device for accommodating a semiconductor device integrated circuit device.

[0002]

2. Description of the Related Art In recent years, as the performance of an information processing apparatus has become higher, the density and the degree of integration of semiconductor elements constituting the information processing apparatus have been rapidly increasing. Therefore, the amount of heat generated per unit area and unit volume generated during operation of the semiconductor element increases, and how to efficiently remove the heat has been an issue in order to operate the semiconductor element normally and stably. .

Conventionally, as a method of removing heat generated by a semiconductor element, the above-described mounting part is generally formed on a metal base made of a copper-tungsten alloy having a mounting part on which the semiconductor element is mounted and fixed at the center of the upper surface. Prepare a semiconductor element storage package having a structure in which an insulating frame made of alumina ceramics is attached via a brazing material such as silver brazing so as to surround it.
The method is performed by mounting and fixing a semiconductor element on a semiconductor element mounting portion of a metal base via a metal plate, absorbing heat generated from the semiconductor element to the metal base, and releasing the absorbed heat to the atmosphere. ing.

A metal wiring layer is embedded in the insulating frame so that each electrode of a semiconductor element housed therein can be electrically connected to an external electric circuit via the metal wiring layer. Has become.

The metal plate interposed between the semiconductor element mounting portion of the metal base and the semiconductor element acts to relieve thermal stress caused by the difference in thermal expansion coefficient between the metal base and the semiconductor element. The plate is formed by punching and is arranged such that a burr surface formed at the time of punching is on the semiconductor element side.

[0006] Further, the metal plate is plated with nickel or gold on its outer surface so that the metal plate and the semiconductor element can be easily and firmly joined to each other by applying a nickel plating film or a gold plating film. Has become.

[0007]

However, in the conventional package for accommodating a semiconductor element, when a metal plate is formed by punching, a bent burr is formed on an outer peripheral portion, and this burr is formed on the outer surface of the metal plate by nickel. plating,
When gold plating is performed, a residual plating solution is allowed.
Therefore, when the semiconductor element is bonded to the surface having the bent burrs, when heat at the time of bonding the semiconductor elements is applied to the metal plate, a plating solution remaining on the bent burrs vaporizes and expands, and a nickel plating film, There is a drawback that the gold plating film is peeled off from the metal plate and the bonding strength between the semiconductor element and the metal plate is greatly reduced.

[0008]

According to the present invention, an insulating frame is attached to a metal base having a mounting portion on which a semiconductor element is mounted and fixed via a metal plate so as to surround the mounting portion. In the semiconductor device housing package, the metal plate for mounting and fixing the semiconductor element on the metal base is arranged so that a burr surface formed by punching is on the metal base side. Is what you do.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing one embodiment of a package for housing a semiconductor device according to the present invention, wherein 1 is a metal base, 2 is a metal plate, and 3 is an insulating frame.

The metal substrate 1 is provided with a convex mounting portion 1a on which a semiconductor element is mounted at the center of the upper surface thereof. On the convex mounting portion 1a, a semiconductor element 4 is provided with a metal plate 2 on which a semiconductor plate is mounted. It is placed and fixed with sandwiched between.

The metal base 1 functions to absorb the heat generated by the semiconductor element 4 and release the absorbed heat to the atmosphere, so that a large thermal stress is not generated between the metal base 1 and the insulating frame 3 described later. It is formed of a material having a thermal expansion coefficient close to that of the insulating frame 3 and having good thermal conductivity, for example, a copper-tungsten alloy (Cu-W alloy).

The metal substrate 1 made of the copper-tungsten alloy is made of, for example, tungsten powder (about 10 μm).
This is pressed at a pressure of 00 kg / cm ² and fired at a temperature of about 2300 ° C. in a reducing atmosphere to obtain a porous tungsten sintered body. It is formed by impregnating the porous portion of the tungsten sintered body using a capillary phenomenon.

An insulating frame 3 is attached to the metal base 1 so as to surround a convex mounting portion 1a provided on the upper surface of the metal base 1 at the outer peripheral end of the upper surface. A space for accommodating the semiconductor element 4 is formed with the insulating frame 3.

The insulating frame 3 is made of an electrical insulating material such as alumina ceramics. For example, a suitable organic solvent and a solvent are added to and mixed with alumina ceramic powder to form a slurry, and this is formed by a doctor blade method. To form a green sheet (ceramic green sheet). Thereafter, the green sheet is subjected to an appropriate punching process, and a plurality of the green sheets are laminated and fired at a high temperature.

The insulating frame 3 has a metallized metal layer 5 made of a refractory metal powder such as tungsten or molybdenum adhered on the lower surface thereof. It is mounted on the metal substrate 1 by brazing through the material 6.

A conductive layer 7 made of a high melting point metal powder such as molybdenum or tungsten is provided inside the insulating frame 3.
The conductive layer 7 serves to connect the electrode of the semiconductor element 4 to the external lead pin 8, and the external lead pin 8 is connected to one end of the conductive layer 7, and the bonding wire is connected to the electrode of the semiconductor element 4 at the other end. 9 is attached.

The external lead pins 8 attached to the conductive layer 7 provided on the insulating frame 3 serve to connect each electrode of the semiconductor element 4 housed therein to an external electric circuit, so that the Kovar metal Fe-Ni A rod-shaped metal such as -Co alloy) or 42 alloy (Fe-Ni alloy) is used.

A good conductive and corrosion-resistant metal made of nickel (Ni) or gold (Au) is applied on the outer surface of the external lead pin 8 by plating to a thickness of 2 to 20 μm. By doing so, the electrical connection between the external lead pins 8 and the external electric circuit is improved, and oxidation corrosion of the external lead pins 8 is effectively prevented. Therefore, in order to prevent the external lead pins 8 from being oxidized and corroded and to improve the electrical connection with an external electric circuit, nickel (Ni) or gold
(Au) made of highly conductive and corrosion resistant metal
It is preferable to coat the layer to a thickness of from 20 to 20 μm.

Further, as shown in FIG. 2, the metal substrate 1 having the insulating frame 3 attached to the upper surface thereof has a semiconductor element mounting portion 1a.
The semiconductor element 4 is mounted and fixed with the metal plate 2 interposed therebetween.

A metal plate 2 sandwiched between the semiconductor element mounting portion 1a of the metal base 1 and the semiconductor element 4 acts to relieve thermal stress caused by a difference in thermal expansion coefficient between the metal base 1 and the semiconductor element 4. Therefore, a metal material having a coefficient of thermal expansion between the metal substrate 1 and the semiconductor element 4, specifically, molybdenum is preferably used.

The metal plate 2 is formed by punching a thin plate of molybdenum into a predetermined shape by a punching method. The metal plate 2 has a burr 2a formed at the time of punching and a metal substrate 1 on the semiconductor element mounting portion 1a side of the metal base 1. In this way, it is attached to the upper surface of the semiconductor element mounting portion 1a of the metal base 1 via a brazing material 10 such as silver brazing. In this case, since the brazing material 10 enters the bent burr 2a, the brazing strength between the metal plate 2 and the metal base 1 is greatly improved, and a nickel plating film or a gold plating film described later is formed on the outer surface of the metal plate 2. At the time of layering, the plating solution is effectively prevented from entering and remaining in the bent burr 2a, and the bonding strength between the metal plate 2 and the semiconductor element 4 can be made extremely high.

On the outer surface of the metal plate 2, a plating film 10 having a two-layer structure composed of a nickel film and a gold film is layered, and the nickel film of the plating film 10 is a gold film on the surface of the metal plate 2. Acts firmly, and the gold film is
4 Make a eutectic alloy with silicon that constitutes
Is firmly bonded on the metal plate 2.

The plating film 10 having a two-layer structure composed of the nickel film and the gold film is formed on the outer surface of the metal plate 2 by employing a conventionally known electrolytic plating method or electroless plating method. . In this case, since the brazing material 10 is filled in the bent burr 2a of the metal plate 2, the plating solution hardly enters the burr 2a and remains, and as a result,
When the semiconductor element 4 is bonded onto the metal plate 2, even if heat is applied to the metal plate 2, the plating film 10 does not peel off due to the vaporization and expansion of the plating solution remaining in the burr 2 a. 4 can be firmly joined to the metal plate 2.

Thus, according to the package for housing a semiconductor element of the present invention, the semiconductor element 4 is bonded and fixed to the metal plate 2 attached on the semiconductor element mounting portion 1a of the metal base 1, and each electrode of the semiconductor element 4 is fixed. The bonding layer 9 through the conductive layer
7 and the lid 11 is attached to the upper surface of the insulating frame 3 via a sealing material, whereby a semiconductor device as a final product is obtained.

The present invention is not limited to the embodiment described above, and various modifications can be made without departing from the scope of the present invention.

[0026]

According to the package for housing a semiconductor element of the present invention, a metal plate to which a semiconductor element is directly joined is mounted such that burrs formed on the metal plate face the metal substrate. When the metal plate is brazed to the semiconductor element mounting portion of the metal base because it is arranged in the mounting portion, a part of the brazing material enters into the burr of the metal plate and the metal plate and the semiconductor element mounting portion of the metal base are Can greatly improve the brazing strength.

Further, when brazing a metal plate to a semiconductor element mounting portion of a metal substrate, since a brazing material enters into burrs of the metal plate, when a nickel plating film and a gold plating film are deposited on the outer surface of the metal plate, The plating solution hardly enters the burrs and remains. As a result, when the semiconductor element is bonded to the metal plate, even if heat is applied to the metal plate, the plating film is formed of the plating solution remaining in the burrs. There is no peeling due to vaporization and expansion, and the semiconductor element can be firmly joined to the metal plate.

[Brief description of the drawings]

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

2 is an enlarged cross-sectional view of a main part of the package for housing a semiconductor element shown in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Metal base 1a ... Semiconductor element mounting part 2 ... Metal plate 2a ... Burr 3 ... Insulating frame

Claims (1)

(57) [Scope of request for utility model registration] 1. A semiconductor element storage device comprising: a metal base having a mounting portion on which a semiconductor element is mounted and fixed via a metal plate; and an insulating frame body attached to the metal base so as to surround the mounting portion. In the package, the metal plate for mounting and fixing the semiconductor element on the metal base is arranged such that a burr surface formed by punching is on the metal base side.