JPH06120363A - Semiconductor device holding package - Google Patents

Abstract

PURPOSE:To make a semiconductor device operate normally and stably over a long period of time by brazing a metal frame firmly to a metallized metal layer attached to an insulating substrate made of an aluminum nitride sintered body or glass ceramic sintered body, sealing the container hermetically completely, and making it hold the semiconductor device inside. CONSTITUTION:This semiconductor device holding package is one made by brazing a metal frame 8 to a metallized layer 7 provided on the surface of an insulating substrate 1, and fitting a metal lid 2 to the metal frame 8 to hold a semiconductor device 3 inside hermetically. And, the insulating substrate 1 is made of an aluminum nitride sintered body or glass ceramic sintered body, and the Vickers hardness (Hv) of soldering material 9 for soldering the metal frame 8 to the metallized layer 7 satisfies Hv <=40.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a semiconductor element housing package for housing a semiconductor element.

[0002]

2. Description of the Related Art Conventionally, a semiconductor element housing package for housing a semiconductor element is usually made of an electrically insulating material such as an aluminum oxide sintered body, and the semiconductor element is housed in a substantially central portion of its upper surface. Of the concave portion and tungsten, molybdenum led from the periphery of the concave portion to the peripheral portion,
An insulating substrate having a metallized wiring layer made of a refractory metal powder such as manganese was brazed to the metallized wiring layer via a brazing material such as silver brazing in order to electrically connect the semiconductor element to an external electric circuit. An external lead terminal and a lid body made of metal such as Kovar metal or 42 alloy are used. The semiconductor element is attached and fixed to the bottom surface of the recess of the insulating base, and each electrode of the semiconductor element is bonded via a bonding wire. After connecting to the metallized wiring layer, a metal lid is then welded to the upper surface of the insulating base, and the semiconductor element is hermetically sealed inside the container consisting of the insulating base and the metal lid to form a semiconductor as a final product. It becomes a device.

In the conventional package for accommodating semiconductor elements, a metal frame made of a metal material such as Kovar metal or 42 alloy is usually brazed on the upper surface of an insulating base, and the metal frame is made of metal. By welding the lid by the seam weld method or the like, the metallic lid is attached to the upper surface of the insulating base, thereby hermetically sealing the container including the insulating base and the metallic lid.

For brazing a metal frame to the insulating base, a metallized metal layer made of a refractory metal powder such as tungsten, molybdenum, or manganese is formed on the upper surface of the insulating base in a slightly larger area than the metal frame. The film is formed by applying a thick film technique such as the screen printing method, and then a brazing material such as a silver brazing material and a metal frame are sequentially placed on the metallized metal layer, and finally the brazing material is formed. About 80
It is performed by applying a temperature of 0 ° C. and heating and melting the brazing material.

However, in recent years, the density and speed of semiconductor devices have rapidly increased, and when the semiconductor devices are housed in the conventional semiconductor device housing package described above, the semiconductor devices have the following drawbacks.

(1) The coefficient of thermal expansion of silicon constituting a semiconductor element and the coefficient of thermal expansion of an aluminum oxide sintered body constituting an insulating substrate of a package for accommodating a semiconductor element are 3.0 to 3.5 × 10 ^{−6 /} ° C. and 7.5, respectively.
Since it is × 10 ^-6 / ° C., it is greatly different, and when heat generated when the semiconductor element is operated is applied to both, a large thermal stress occurs between the two, and the semiconductor element is caused by the thermal stress. It may be damaged or the semiconductor element may be peeled off from the insulating substrate and the function as a semiconductor device may be lost.

(2) The thermal conductivity of the aluminum oxide sintered body that constitutes the insulating substrate of the semiconductor element housing package is about
Since it is as low as 20 W / mK, the insulating substrate cannot dissipate the heat generated during the operation of the semiconductor element into the atmosphere well, and the semiconductor element becomes high temperature due to the heat generated by the semiconductor element, and the semiconductor element is not heated. It may cause damage or change the characteristics due to heat, resulting in malfunction.

(3) The dielectric constant of the aluminum oxide sintered body that constitutes the insulating substrate of the package for storing semiconductor elements is
Since it is as high as 9 to 10 (room temperature 1 MHz), the propagation speed of the electric signal transmitted through the metallized wiring layer provided on the insulating substrate is slow, and therefore the semiconductor element that requires high-speed signal propagation cannot be accommodated.

It has the drawbacks such as

Therefore, in order to solve the above-mentioned drawbacks, the insulating base of the package for housing a semiconductor element is made of aluminum nitride having a low thermal conductivity and a high thermal conductivity similar to that of silicon constituting the semiconductor element. It has been studied to form a body or a glass ceramics sintered body containing a large amount of glass components.

[0011]

However, a package for storing a semiconductor element, which uses the aluminum nitride sintered body or the glass ceramics sintered body as an insulating substrate, is not suitable for the aluminum nitride sintered body or the glass ceramics sintered body. The coefficient of thermal expansion is 5.0 × 10 ^-6 / ° C or less, whereas the coefficient of thermal expansion of Kovar metal or 42 alloy, which composes the metal frame, is about 7.0 × 10 ^-6 / ° C, and both are different. , When the metal frame is brazed to the metallized metal layer adhered to the insulating substrate, due to the difference in thermal expansion coefficient between the insulating substrate and the metal frame at the joint between the metallized metal layer of the insulating substrate and the metal frame. There is a large internal thermal stress, and as a result, when a metal lid is attached to the metal frame by welding, if an external force is applied to the metal frame, the external force will increase in proportion to the internal stress. ,
The metal frame is peeled off from the insulating base to break the hermetic seal of the container, and the semiconductor element housed inside is kept normal for a long period of time.
In addition, it has a drawback that it cannot be operated stably.

[0012]

SUMMARY OF THE INVENTION The present invention has been devised in view of the above drawbacks, and its object is to provide a metal frame on a metallized metal layer adhered to an insulating substrate made of an aluminum nitride sintered body or a glass ceramic sintered body. It is an object of the present invention to provide a package for storing a semiconductor element in which a semiconductor element which is tightly brazed and the container is completely hermetically sealed and can be normally and stably operated for a long period of time.

[0013]

According to the present invention, a metal frame is brazed to a metallized metal layer provided on the surface of an insulating substrate, a metal lid is attached to the metal frame, and a semiconductor element is provided inside. A package for housing a semiconductor element, which is hermetically housed, wherein the insulating substrate is formed of an aluminum nitride sintered body or a glass ceramic sintered body, and a metal frame is brazed to a metallized metal layer. The Vickers hardness (Hv) of the material is Hv ≦ 40.

[0014]

According to the package for accommodating semiconductor elements of the present invention, the thermal stress generated by the difference in the thermal expansion coefficient between the insulating base made of the aluminum nitride sintered body or the glass ceramic sintered body and the metal frame is between the two. It is absorbed by the brazing material interposed between the metal base and the metallized metal layer adhered to the insulating substrate, so that the metal frame can be firmly brazed.

[0015]

The present invention will now be described in detail with reference to the accompanying drawings. 1 and 2 show an embodiment of a package for housing a semiconductor element of the present invention, in which 1 is an insulating base and 2 is a metallic lid. The insulating base 1 and the metallic lid 2 constitute a container that houses the semiconductor element 3.

The insulating base 1 is made of an aluminum nitride sintered body or a glass ceramics sintered body, and has a concave portion for forming a space for accommodating the semiconductor element 3 in the central portion of the upper surface thereof.
1a is provided, and the semiconductor element 3 is attached to the bottom surface of the recess 1a via an adhesive such as a brazing material, glass, or resin.

The thermal expansion coefficient of the aluminum nitride-based sintered body or the glass-ceramics sintered body forming the insulating substrate 1 is 5.0 × 10 ⁻⁶ / ° C. or less, and the thermal expansion coefficient of silicon forming the semiconductor element 3 is Since it is close to (3.0 to 3.5 × 10 ^-6 / ° C), after mounting the semiconductor element 3 on the bottom surface of the concave portion 1a of the insulating substrate 1, between the insulating substrate 1 and the semiconductor element 3, for example, the operation of the semiconductor element 3 Even if heat generated at times is applied, a large thermal stress does not occur between them, and the thermal stress may damage the semiconductor element 3 or cause the semiconductor element 3 to be damaged.
There is no loss of the function as a semiconductor device by peeling 3 from the insulating substrate 1.

If the semiconductor element 3 attached to the bottom surface of the recess 1a is of a type that generates a large amount of heat, the insulating substrate 1 is an aluminum nitride sintered material having a thermal conductivity of 80 W / m.K or more. If formed in a body, the insulating substrate 1 can satisfactorily dissipate the heat generated by the semiconductor element 3 into the atmosphere, and the semiconductor element 3 can be normally operated at a low temperature for a long period of time to operate normally.

When the insulating substrate 1 is made of, for example, an aluminum nitride sintered body, yttria or calcia as a sintering aid and an appropriate organic solvent or solvent are added to aluminum nitride (AlN) as a main raw material. By mixing them to form a sludge and adopting the conventionally known doctor blade method and calender roll method, the green sheet
(Green sheet) is formed, and thereafter, the green sheet is appropriately punched, laminated with a plurality of sheets, and fired at a high temperature (about 1800 ° C.).

A plurality of metallized wiring layers 4 are formed on the insulating substrate 1 from the periphery of the recess 1a to the outer peripheral edge thereof, and the electrodes of the semiconductor element 3 are formed on the periphery of the recess 1a of the metallized wiring layer 4. An external lead terminal 6 is brazed via a brazing material to a portion that is electrically connected via a bonding wire 5 and is led to the outer peripheral edge of the insulating base 1.

Metallized wiring layer provided on the insulating substrate 1
4 is made of metal powder such as tungsten, molybdenum and manganese, and the metallized wiring layer 4 has a function of electrically connecting each electrode of the semiconductor element 3 to an external lead terminal 6 connected to an external electric circuit.

For the metallized wiring layer 4, for example, a metal paste obtained by adding and mixing an organic solvent and a solvent to a metal powder such as tungsten is formed in a predetermined pattern in advance on a green sheet to be the insulating substrate 1 by a conventionally known screen printing method. By printing and coating, the insulating substrate 1 is adhered and formed at a predetermined position.

The metallized wiring layer 4 is formed on its exposed outer surface with a metal such as nickel and gold which has excellent corrosion resistance and has a good wettability with the brazing material by 1.0 to 20.0 μm by plating.
The thickness of the metallized wiring layer 4 can effectively prevent oxidative corrosion of the metallized wiring layer 4, and the brazed joint between the metallized wiring layer 4 and the bonding wires 5 and the external lead terminals 6 can be strengthened. You can Therefore, it is preferable to deposit a metal such as nickel or gold having excellent corrosion resistance and good wettability with the brazing material to a thickness of 1.0 to 20.0 μm on the surface of the metallized wiring layer 4 by a plating method.

The metallized wiring layer 4 provided on the insulating base 1 is a metallized wiring layer if the insulating base 1 is formed of a glass ceramic sintered body having a low dielectric constant of about 6.3.
The propagation speed of the electric signal transmitted through 4 becomes extremely high, and the semiconductor element 3 attached to the bottom surface of the recess 1a of the insulating substrate 1
In the case of a high-speed drive type in which electric signals are input and output at high speed, it is preferable that the insulating substrate 1 on which the metallized wiring layer 4 is formed is formed of a glass ceramic sintered body having a low dielectric constant.

Further, the external lead terminals 6 brazed to the metallized wiring layer 4 deposited on the insulating substrate 1 are made of a metal material such as Kovar metal (iron-nickel-cobalt alloy) or 42 alloy (iron-nickel alloy). , To electrically connect each electrode of the semiconductor element 3 to an external electric circuit.

The external lead terminal 6 is manufactured by forming an ingot (lump) of Kovar metal or the like into a predetermined rod shape by using a conventionally known metal processing method such as a rolling processing method or a punching processing method.

The brazing material for brazing the external lead terminal 6 and the metallized wiring layer 4 provided on the insulating substrate 1 is, for example, a soft material having a Vickers hardness (Hv) of Hv ≦ 40 such as a gold-silver alloy. When the Vickers hardness (Hv) is Hv ≤ 40 as the brazing material, it is suitable to braze and attach the external lead terminal 6 to the metallized wiring layer 4 provided on the insulating substrate 1. Even if the thermal expansion coefficient differs from that of the lead terminal 6 and a large thermal stress is generated between the two, the stress is absorbed by deforming the brazing material, and there is no large internal stress in the brazing part of both. Thus, the external lead terminal 6 can be firmly attached to the metallized wiring layer 4. Therefore, as the brazing material for brazing the external lead terminals 6 to the metallized wiring layer 4 of the insulating substrate 1, it is preferable to use a soft material having a Vickers hardness (Hv) of Hv ≦ 40 such as gold-silver alloy.

On the other hand, a metallized metal layer 7 is deposited on the upper surface of the insulating substrate 1, and a metal frame 8 is brazed to the metallized metal layer 7 via a brazing material 9.

Metallized metal layer 7 on the upper surface of the insulating substrate 1
Is made of a refractory metal powder such as tungsten, molybdenum, or manganese, and the metallized metal layer 7 acts as a base metal layer when the metal frame 8 is brazed to the insulating base 1.

The metallized metal layer 7 is preliminarily predetermined by a well-known screen printing method or the like on a green sheet serving as the insulating substrate 1 with a metal paste obtained by adding and mixing an appropriate organic solvent and a solvent to a metal powder such as tungsten. It is adhered and formed on the upper surface of the insulating substrate 1 by printing and coating it to a thickness.

The metal frame 8 brazed to the metallized metal layer 7 via the brazing material 9 is made of Kovar metal or 42
Insulate base 1 with metal lid 2 made of metal material such as alloy
Acts as a base metal member when attaching to the metal frame 8
The metallic lid body 2 is attached to the insulating base 1 by welding the metallic lid body 2 to it by a seam wet method or the like.

The metal frame 8 is made of a metal material such as Kovar metal or 42 alloy, and the ingot of Kovar metal or the like is used.
The (lump) is formed into a predetermined frame shape by adopting a conventionally known metal processing method such as a rolling processing method or a punching processing method.

The metal frame body 8 is also brazed to the metallized metal layer 7 provided on the insulating substrate 1 via the brazing material 9.
As the brazing material 9, for example, a soft material such as a gold-silver alloy having a Vickers hardness (Hv) of Hv ≦ 40 is used.

The brazing material 9 has a Vickers hardness (Hv)
Since Hv ≤ 40 is soft, when the metal frame 8 is brazed and attached to the metallized metal layer 7 provided on the insulating substrate 1, the insulating substrate 1 and the metal frame 8 have different thermal expansion coefficients. ,
Even if a large thermal stress is generated between the two, the stress is absorbed by deforming the brazing material 9, and no large stress is present in the brazing portion of both. Therefore,
After brazing, even if an external force is applied to the metal frame body 8, the external force becomes large in proportion to the stress inherent in the brazing portion,
The metal frame 8 is not peeled off either.

The brazing material 9 has a Vickers hardness (H
When v) is Hv ≧ 40, when the metal frame body 8 is brazed and attached to the metallized metal layer 7 provided on the insulating base body 1, large stress is internally present in the joint portion between the insulating base body 1 and the metal frame body 8, Due to the internal stress, the metal frame body 8 is easily separated from the insulating substrate 1. Therefore, the brazing material 9 has a Vickers hardness (Hv) of
Specified as soft with Hv ≤ 40.

Thus, according to the above-mentioned package for accommodating semiconductor elements, the semiconductor element 3 is attached to the bottom surface of the recess 1a of the insulating substrate 1 via an adhesive such as a brazing material, glass or resin, and each electrode of the semiconductor element 3 is attached. Is electrically connected to the metallized wiring layer 4 via the bonding wire 5, and then,
The metal lid body 2 is welded to the metal frame body 9 brazed to the upper surface of the insulating base body 1 by the seam weld method or the like, and the semiconductor element 3 is hermetically sealed inside the container composed of the insulating base body 1 and the metal lid body 2. When stopped, the final semiconductor device is obtained.

The present invention is not limited to the above-mentioned package for accommodating semiconductor elements, and various modifications can be made without departing from the scope of the present invention.

[0038]

According to the package for accommodating semiconductor elements of the present invention, a metallized metal layer is adhered to an insulating substrate made of an aluminum nitride sintered body or a glass ceramic sintered body, and a metal frame body is formed on the metallized metal layer. When the metal frame body is brazed and attached to the metallized metal layer provided on the insulating substrate, the insulating base body and the metal frame body are attached by brazing through a brazing material having a Vickers hardness (Hv) of Hv ≦ 40. Even if a large thermal stress is generated between the two and the two have different thermal expansion coefficients, the stress is absorbed by deforming the brazing material, and no large stress is inherently present in the brazing portion of both. Therefore, even if an external force is applied to the metal frame body after brazing, the external force becomes large in proportion to the internal stress of the brazing portion, and the metal frame body is never peeled off from the insulating substrate. It becomes possible to operate the semiconductor element housed inside completely and hermetically sealing the container normally and stably for a long period of time.

Further, since the insulating base is made of an aluminum nitride sintered body or a glass ceramic sintered body, the thermal expansion coefficient of the insulating base can be approximated to the thermal expansion coefficient of the semiconductor element. After attaching the semiconductor element, even if heat is applied between the insulating substrate and the semiconductor element, a large thermal stress does not occur between them,
There is no possibility of damaging the semiconductor element by the thermal stress or peeling the semiconductor element from the insulating substrate to lose its function as a semiconductor device.

Further, if the insulating substrate is made of an aluminum nitride sintered body, the thermal conductivity of the insulating substrate becomes 80 W / mK or more, and as a result, the semiconductor element housed inside generates a large amount of heat during operation. However, the heat is well dissipated in the atmosphere, and it becomes possible to keep the semiconductor element at a low temperature and operate it normally for a long time.

Further, if the insulating substrate is made of a glass ceramic sintered body having a low dielectric constant, the propagation speed of the electric signal transmitted through the metallized wiring layer provided on the insulating substrate can be made extremely high, resulting in insulation. It is also possible to house a high-speed drive type semiconductor element that inputs and outputs electrical signals at high speed inside a container composed of a base body and a lid.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a package for housing a semiconductor device of the present invention.

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

[Explanation of symbols]

 1 ... Insulating substrate 2 ... Lid 3 ... Semiconductor element 4 ... Metallized wiring layer 6 ... External lead terminal 7 ... Metallized metal Layer 8: Metal frame 9: Brazing material

Claims (1)

[Claims] 1. A metal frame is brazed to a metallized metal layer provided on the surface of an insulating substrate, a metal lid is attached to the metal frame, and a semiconductor element is hermetically housed therein. Vickers hardness (Hv) of a brazing material in which the insulating substrate is formed of an aluminum nitride sintered body or a glass ceramics sintered body and a metal frame is brazed to a metallized metal layer. Is Hv ≦ 40.