JP2724083B2 - 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 a semiconductor device housing package for housing a semiconductor device.

[0002]

2. Description of the Related Art Conventionally, semiconductor device housing packages for housing semiconductor devices, particularly semiconductor devices such as LSIs,
For example, a plug-in type semiconductor element housing package is made of an electrically insulating material such as alumina ceramics, has a concave portion for housing the semiconductor element at a substantially central portion of the upper surface, and is led out from the periphery of the concave portion to the lower surface. A quadrangular insulating base having a metallized wiring layer made of a refractory metal powder such as tungsten, molybdenum, and manganese;
An external lead terminal attached to the metallized wiring layer via a brazing material such as silver brazing to electrically connect the semiconductor element to an external electric circuit, and a rectangular lid made of an electrically insulating material such as alumina ceramics And is composed of
The semiconductor element is attached and fixed to the bottom of the concave portion of the insulating base via an adhesive, and each electrode of the semiconductor element is electrically connected to the metallized wiring layer via a bonding wire, and the lid is soldered to the upper surface of the insulating base. A semiconductor device as a product is obtained by joining the semiconductor element with a sealing material made of the above and the like, and hermetically sealing the semiconductor element inside a container formed of an insulating base and a lid.

In such a conventional package for housing a semiconductor element, an insulating base and a lid are joined together by forming a metal layer made of a high melting point metal powder such as tungsten, molybdenum, manganese or the like on the upper surface of the insulating base. A metal layer made of silver-palladium is formed on the lower surface and the entire side surface, respectively, and the metal layers of the insulating base and the lid are joined to each other via solder as a sealing material. This is done by forming a pool of solder between the upper metal layer.

The metal layer of the lid is formed by applying a well-known screen printing method to the lower and side surfaces of the lid by applying a metal paste obtained by adding a suitable organic solvent and a solvent to silver-palladium powder. By printing and applying to a predetermined thickness, and then baking it, the cover is attached to the lower surface and the entire side surface of the lid.

However, in this conventional package for accommodating a semiconductor element, the lid has a quadrangular shape, each side edge is angular, and the lid is made of fragile alumina ceramics and has a thickness of 0.6 mm. After the semiconductor element is hermetically housed in a container formed of an insulating base and a lid because of its degree and thickness, when an external force is applied to the lid, the external force concentrates on each corner of the side surface of the lid. Chipping occurs,
As a result, the hermetic sealing of the container is broken, and the semiconductor element contained therein cannot be normally and stably operated for a long time.

Therefore, in order to solve the above-mentioned drawback, each corner of the side face of the lid is processed into an arc shape having a radius of 0.5 mm or more to prevent the external force from concentrating on each corner of the side face, and to mechanically operate the lid. Improvements in strength have been made.

[0007]

However, if each corner of the side surface of the lid is processed into an arc shape, a metal paste is applied to the side surface of the lid by a screen printing method, and the metal is applied all around the side surface of the lid. When the layer is applied, each corner of the side surface of the lid has an arc shape, and the metal layer cannot be applied to each corner of the side surface of the lid because it does not adhere to the screen mask. By bonding the metal layer on the upper surface of the base and the metal layers on the lower surface and the side surfaces of the lid via solder as a sealing material, and sealing the semiconductor element in a container including the insulating substrate and the lid in an airtight manner. In the case of a semiconductor device, a region where no solder pool exists is formed at each corner of the side surface of the lid. Therefore, in this semiconductor device, when the heat generated during the operation of the semiconductor element is repeatedly applied to the sealing material (solder), the stress due to the expansion and contraction of the solder concentrates on the area where the solder pool does not exist, and the concentrated stress causes the lid to be closed. A semiconductor that generates cracks in a sealing material (solder) disposed between a lower surface metal layer and a metal layer on an upper surface of an insulating substrate, and breaks hermetic sealing of a container including an insulating substrate and a lid, and accommodates the semiconductor inside the container. This causes a disadvantage that the element cannot be operated normally and stably for a long period of time.

[0008]

SUMMARY OF THE INVENTION The present invention has been devised in view of the above-mentioned drawbacks, and has as its object to completely seal hermetically in a container comprising an insulating base and a lid, and to provide a semiconductor device accommodated therein for a long period of time. Another object of the present invention is to provide a semiconductor device housing package that can be operated normally and stably.

[0009]

SUMMARY OF THE INVENTION The present invention comprises an insulating substrate having a metal layer on the upper surface and a lid having a metal layer on the entire lower surface and side surfaces. In a semiconductor element housing package in which a semiconductor element is hermetically sealed by joining layers via a sealing material, a flat surface of 0.5 mm or more is formed on each side corner of the lid, and The angle between both ends formed by the flat surface and the side surface is 120 ° or more.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

FIGS. 1 and 2 show a semiconductor device housing package of the present invention, taking a plug-in type semiconductor device housing package as an example. Reference numeral 1 denotes an insulating base, and 2 denotes a lid. The insulating base 1 and the lid 2 constitute a container 4 for housing the semiconductor element 3.

The insulating substrate 1 is made of an electrically insulating material such as alumina ceramics, and has a recess 1a for forming a space for accommodating the semiconductor element 3 at a substantially central portion of the upper surface thereof, and a bottom surface of the recess 1a. The semiconductor element 3 is attached via an adhesive such as an epoxy resin.

When the insulating base 1 is made of alumina ceramics, for example, alumina (Al ₂ O ₃ ), silica (SiO ₂ ), calcia (CaO), magnesia (Mg
O) or the like, an appropriate organic solvent and a solvent are added and mixed to form a slurry, and a ceramic green sheet (green ceramic sheet) is formed by employing a conventionally known doctor blade method or calender roll method. After the formation, the ceramic green sheet is manufactured by subjecting the ceramic green sheet to appropriate punching, laminating a plurality of sheets, and firing at a high temperature (about 1600 ° C.).

A plurality of metallized wiring layers 5 extending from the periphery of the concave portion 1a to the lower surface are formed on the insulating base 1, and each electrode of the semiconductor element 3 is bonded around the concave portion 1a of the metallized wiring layer 5. External lead terminals 7 electrically connected via wires 6 and connected to an external electric circuit are attached to portions led out to the lower surface via a brazing material such as silver brazing.

The metallized wiring layer 5 is made of tungsten,
A metal paste made of a high melting point metal powder such as molybdenum, manganese or the like, obtained by adding and mixing an appropriate organic solvent and a solvent to the high melting point metal powder is applied to a ceramic green sheet serving as the insulating substrate 1 in advance by a screen printing method known in the art. By printing and applying in such a manner as described above, the insulating substrate 1 is formed so as to adhere from the periphery to the lower surface of the concave portion 1a.

The metallized wiring layer 5 is formed by depositing a metal having good conductivity and excellent corrosion resistance, such as nickel or gold, to a thickness of 0.1 to 20.0 μm on the exposed surface by plating. By doing so, oxidation corrosion of the metallized wiring layer 5 can be effectively prevented, and the connection between the metallized wiring layer 5 and the bonding wire 6 and the brazing between the metallized wiring layer 5 and the external lead terminals 7 are extremely strong. I can do it. Therefore, in order to prevent the metallized wiring layer 5 from being oxidized and corroded, and to firmly connect the metallized wiring layer 5 to the bonding wires 6 and braze the metallized wiring layer 5 to the external lead terminals 7, Nickel, gold, etc. on exposed surface 1.0 to 2
It is preferable that the layer is deposited to a thickness of 0.0 μm.

The external lead terminals 7 brazed to the metallized wiring layer 5 serve to connect the semiconductor element 3 housed therein to an external electric circuit.
Is connected to an external electric circuit, whereby the semiconductor element 3 housed inside is electrically connected to the external electric circuit via the metallized wiring layer 5 and the external lead terminals 7.

The external lead terminal 7 is made of Kovar metal (F
e-Ni-Co alloy) and 42 alloy (Fe-Ni alloy)
The ingot (lumps) of Kovar metal or the like is formed into a predetermined plate shape by employing a conventionally known metal working method such as a rolling method or a punching method.

The insulating substrate 1 also has a metal layer 8 on its upper surface.
The lid 2 is joined to the metal layer 8 via a sealing material 9 made of solder, whereby the semiconductor element is placed inside the container 4 composed of the insulating base 1 and the lid 2. 3 is hermetically sealed.

The metal layer 8 formed on the upper surface of the insulating base 1 is made of a high melting point metal powder such as tungsten, molybdenum, manganese or the like, and an appropriate organic solvent or solvent is added to the high melting point metal powder and mixed. The metal paste thus obtained is applied to a ceramic green sheet serving as the insulating substrate 1 by printing by employing a conventionally known screen printing method, and the ceramic green sheet is fired at a high temperature to form the insulating substrate 1 at the same time as the insulating substrate 1. 1 is formed on the upper surface.

It is preferable that a layer made of nickel and a layer made of gold are sequentially formed on the surface of the metal layer 8 in order to improve the wettability (reactivity) with the sealing material 9.

The lid 2 joined to the upper surface of the insulating base 1 is made of an electrically insulating material such as alumina ceramics.
The lid 2 is joined to the insulating base 1 by joining the metal layer 10 to the metal layer 8 on the upper surface of the insulating base 1 via a sealing material 9 made of solder.

The lid 2 bonded to the upper surface of the insulating base 1 is made of, for example, alumina (Al ₂ O ₃ ), silica (SiO ₂ ),
A raw material powder obtained by adding and mixing an appropriate organic solvent and a solvent to calcia (CaO), magnesia (MgO), etc. is filled in a press mold of a predetermined shape and formed by pressing at a constant pressure. It is manufactured by firing the molded article at a temperature of about 1500 ° C.

The metal layer 10 formed on the outer periphery of the lower surface and the entire periphery of the side surface of the lid 2 is made of a metal material such as silver or silver / palladium. The metal paste obtained by adding and mixing is coated on the lower surface and side surfaces of the lid 2 by a conventionally known screen printing method to a thickness of 10 to 30 μm and baked at a temperature of about 900 ° C. It is formed on the outer periphery of the lower surface and the entire periphery of the side surface.

The lid 2 has a width of 0.5 at each corner of its side surface.
A notch A having a flat surface 2a of not less than 2 mm is formed, and an external force is applied to the lid 2 by the notch A,
The external force is effectively concentrated on each corner of the side surface of the lid 2 to effectively prevent chipping, cracking, and the like from occurring at each corner of the side surface of the lid 2.

The angles α and β of the corners located between the flat surface 2a of the notch A and the side surfaces of the lid 2 are both obtuse angles of 120 ° or more. 2 is applied to each side surface of the lid 2 and the flat surface 2a.
Are not concentrated on the corners between them, and there is no occurrence of chipping or cracking in the lid 2.

Further, since the notch A formed at each corner of the side surface of the lid 2 has a flat surface 2a having a width of 0.5 mm or more, a screen printing method is adopted on the side surface of the lid 2. Thus, when the metal layer 10 is applied, the entire periphery of the side surface of the lid 2 is in close contact with the screen mask, so that the metal layer 10 can be reliably applied to the entire periphery of the side surface of the lid 2. Therefore, the metal layer 8 on the upper surface of the insulating substrate 1 and the metal layer 10 on the lower surface and the side surface of the lid 2 are joined via solder as the sealing material 9, and the inside of the container 4 including the insulating substrate 1 and the lid 2 is joined. When the semiconductor element 3 is hermetically sealed, a solder pool is reliably formed on the entire periphery of the side surface of the lid 2, and the heat generated during the operation of the semiconductor element 3 is repeatedly applied to the sealing material 9 (solder). Even if stress due to the expansion and contraction of the sealing material 9 occurs, the stress is dispersed throughout the sealing material 9 and becomes small, and cracks are not generated in the sealing material 9 and the hermetic sealing of the container 4 is never broken.

The notch A formed at each corner of the side surface of the lid 2 has a flat surface 2a having a width of less than 0.5 mm. The external force concentrates on each corner of the side surface, causing chipping or cracking of the lid 2, and the metal layer 10 cannot be adhered by employing the screen printing method on the flat surface 2 a. Therefore, the notch A formed at each corner of the side surface of the lid 2 is specified to have a flat surface 2a having a width of 0.5 mm or more.

The flat surface 2a of the notch A and the lid 2
Angles α and β of the corners located between the respective side surfaces are 120 °
If it is less than this, when an external force is applied to the lid 2, the external force concentrates on the corners, causing the lid 2 to chip or crack. Therefore, the angles α and β of the corners located between the flat surface 2 a of the notch A and the respective side surfaces of the lid 2 are both specified to be 120 ° or more.

Thus, according to the package for housing a semiconductor element described above, the semiconductor element 3
Are attached via an adhesive and the respective electrodes of the semiconductor element 3 are electrically connected to the metallized wiring layer 5 via bonding wires 6. Thereafter, the metal layer 8 attached to the upper surface of the insulating substrate 1 is formed. And a metal layer 10 attached to the lower surface and side surfaces of the lid 2 via a sealing material 9 made of solder,
A semiconductor device as a product is obtained by hermetically sealing the semiconductor element 3 inside a container 4 including the insulating base 1 and the lid 2.

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 gist of the present invention. Although the metal layer 10 made of silver / palladium is formed on the outer periphery of the lower surface and the entire periphery of the side surface, it may be formed of the same material as the metal layer 8 formed on the upper surface of the insulating base 1, that is, tungsten, molybdenum, or the like. .

In the above-described embodiment, a plug-in type semiconductor element storage package is described as an example. However, the present invention can be applied to other semiconductor element storage packages such as a dual in-line type.

[0033]

According to the semiconductor device housing package of the present invention, each corner of the side of the lid has a flat surface of 0.5 mm or more, and the angle between the flat surface and the side is 120 ° or more. Even when an external force is applied to the lid, the external force is dispersed throughout the lid and does not concentrate, and as a result, chips or cracks due to the application of the external force are formed on the lid. It does not occur at all, and enables the semiconductor element to be hermetically sealed inside the container consisting of the insulating base and the lid so that the semiconductor element housed therein can be operated normally and stably for a long period of time. it can.

At the same time, a metal layer can be securely applied to the entire periphery of the side surface of the lid, so that a pool of solder, which is a sealing material, can be formed on the entire periphery of the side surface of the lid. Even if heat is applied to the solder, and stress due to expansion and contraction of the solder is generated, the stress is uniformly dispersed throughout the sealing material and becomes small, and cracks are not generated in the sealing material. The container to be housed can be completely hermetically sealed.

[Brief description of the drawings]

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

FIG. 2 is a plan view of a lid of the package shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Insulating base 2 ... Lid 2a ... Flat surface 3 ... Semiconductor element 4 ... Container 5 ... Metallized wiring layer 7 ... External lead terminal 8 ... Metal layer (insulation) 9: sealing material 10: metal layer (lid side) A: notch

Claims (1)

(57) [Claims] 1. An insulating base having a metal layer on an upper surface, and a rectangular lid having a metal layer on an outer peripheral portion of a lower surface and an entire peripheral surface of a side surface. Each metal layer of the insulating base and the lid is made of a brazing material. In a semiconductor element housing package that hermetically seals a semiconductor element inside by joining through a sealing material,
A package having a flat surface having a width of 0.5 mm or more at each corner of the side surface of the lid, and an angle between both ends formed by the flat surface and the side surface being 120 ° or more. .