JP2545400Y2 - 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 semiconductor device housing package for housing a semiconductor device.

[0002]

2. Description of the Related Art Conventionally, a package for accommodating a semiconductor element, particularly a semiconductor integrated circuit element, is made of an electrically insulating material such as alumina ceramics as shown in FIG. An insulating base 11 having a concave portion for forming a place and having a low-melting glass layer 12 for sealing adhered on the upper surface, and an electric insulating material such as alumina ceramics. A lid 13 having a low-melting glass layer 14 for sealing on the lower surface, and a semiconductor element 15 housed therein, which is electrically connected to an external electric circuit. And an external lead terminal 16 for connection.
The external lead terminal 16 is temporarily fixed to the insulating base 11 by mounting the external lead terminal 16 on the upper surface and melting the sealing low-melting glass layer 12 previously applied.
Next, the semiconductor element 15 is attached to the concave portion of the insulating base 11 and each electrode (input / output electrode) of the semiconductor element 15 is connected to the external lead terminal 16 via the bonding wire 17. And a lid 13 are adhered to each of the main surfaces facing each other, and the low melting glass layers 12 and 14 for sealing are used.
Are melted and integrated, and a container formed of the insulating base 11 and the lid 13 is hermetically sealed to provide a semiconductor device as a product.

The low-melting glass layers 12 and 14 for sealing, which are attached to the upper surface of the insulating base 11 and the lower surface of the lid 13, are connected to the insulating base 11 and the lid. A glass whose coefficient of thermal expansion matches the coefficient of thermal expansion of alumina ceramics or the like, for example, lead oxide (PbO) 70 in order to firmly adhere to 13.
0% by weight, boron oxide (B ₂ O ₃ ) 8.6% by weight, titanium oxide
A glass containing 7.8% by weight of (TiO ₂ ) and 6.7% by weight of zirconium oxide (ZrO ₂ ) is used.

However, in recent years, information processing devices such as IC cards have rapidly become thinner, and semiconductor devices mounted on the information processing devices have been required to have a reduced thickness. It has been required to reduce the thickness of the entire package of the semiconductor device housing package constituting the device by making the thickness of the lid about 0.2 mm.

[0005] Therefore, when the thickness of the lid of the above-mentioned conventional package for housing a semiconductor element is set to about 0.2 mm and the thickness of the entire package is reduced, the lid of the package is usually made of an electrically insulating material such as alumina ceramics. Since alumina ceramics are fragile and have low mechanical strength, reducing the thickness of the lid significantly reduces the mechanical strength of the lid, and as a result, the semiconductor element is placed inside the container consisting of the insulating base and the lid. After hermetically sealing and forming a semiconductor device,
When an external force is applied to the lid, the lid is easily damaged by the external force, and the hermetic sealing of the inside of the container is broken, and the semiconductor element housed therein cannot be operated normally and stably for a long period of time. Had the disadvantage that

In order to solve the above-mentioned drawbacks, it is considered that the lid is made of Kovar metal or 42 alloy which has excellent mechanical strength and a thermal expansion coefficient similar to that of the insulating base and the low melting point glass layer for sealing. Can be

However, Kovar metal or 42 alloy has a slight difference in thermal expansion coefficient from that of alumina ceramics and low-melting glass for sealing constituting an insulating base, but has a slight difference (Kovar metal and 42 alloy: 4.4 ~ 5.0 ×
10 ^-6 / ℃, alumina ceramics and low-melting glass for sealing: 6.5 to 7.5 × 10 ^-6 / ℃)
When alloys or the like are used for a large-area lid, the difference in the coefficient of thermal expansion cannot be ignored, and the low-melting glass layer for sealing is melted to hermetically seal the container composed of the insulating base and the lid. When heat for melting the low-melting glass for sealing is applied to both the lid, the insulating substrate, and the low-melting glass layer for sealing, the sealing is performed by thermal stress caused by a difference in thermal expansion coefficient between the two. Cracks and cracks occur in the low-melting glass layer for use, or peeling occurs between the low-melting glass layer for sealing and the lid, and as a result, the hermetic seal of the container is broken and housed inside This causes a disadvantage that the semiconductor element cannot be operated normally and stably for a long period of time.

[0008]

According to the present invention, a semiconductor element and an external lead terminal to which each electrode of the semiconductor element is connected by a bonding wire are sandwiched between an alumina ceramic base and an iron alloy lid. In a semiconductor element housing package in which a semiconductor element is hermetically sealed inside by glass welding of a sealing glass, the sealing glass contains 58.0 to 68.0% by weight of lead oxide, 4.0 to 10.0% by weight of boron oxide, and 2.0% by weight of silicon oxide. A glass containing β-eucryptite as a filler in an amount of from 21.0 to 35.0% by weight in an amount of from 1 to 5.0% by weight.

[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 sectional view showing an embodiment of a package for housing a semiconductor device according to the present invention, wherein 1 is a base and 2 is a lid. The base 1 and the lid 2 constitute a container for housing the semiconductor element 3.

The base 1 is made of alumina ceramics, and has a concave portion 1a for accommodating the semiconductor element 3 at the center of the upper surface thereof, and the semiconductor element 3 is made of glass, resin, brazing material or the like on the bottom surface of the concave portion 1a. It is attached and fixed via an adhesive.

A substrate 1 made of the above alumina ceramics
For example, aluminum oxide (Al ₂ O ₃ ), silica (SiO
₂ ), raw material powders such as magnesia (MgO) and calcia (CaO) are filled in a press mold corresponding to the shape of the substrate 1 shown in FIG. 1 and molded by applying a constant pressure, and thereafter,
It is produced by firing a molded article at a temperature of about 15000 ° C.

On the upper surface of the substrate 1, Kovar metal (F
One end of an external lead terminal 4 made of a metal such as e-Ni-Co alloy) or 42 alloy (Fe-Ni alloy) is temporarily fixed via a low-melting glass 5 for sealing. Is manufactured by forming an ingot (lumps) of Kovar metal or the like into a predetermined plate shape using a conventionally known rolling method and punching method.

The external lead terminal 4 serves to connect the semiconductor element 3 housed therein to an external electric circuit, and one end of each of the electrodes of the semiconductor element 3 is provided with a bonding wire 6.
The semiconductor element 3 is electrically connected to the external electric circuit by connecting the external lead terminal 4 to the external electric circuit.

The external lead terminal 4 may be formed by plating a metal having good conductivity and excellent corrosion resistance made of nickel, gold or the like to a thickness of 1.0 to 20.0 μm by plating. 4 can be effectively prevented and the electrical connection between the external lead terminals 4 and the bonding wires 6 and the external electric circuit can be made good. Therefore, it is preferable that nickel, gold or the like be layered on the surface of the external lead terminal 4 by plating to a thickness of 1.0 to 20.0 μm.

A cover 2 is provided on the upper surface of the base 1 to which the external lead terminals 4 are temporarily fixed, and a low-melting glass 7 for sealing attached to the lower surface of the cover 2 and an upper surface of the base 1 are provided. The low-melting glass 5 for sealing, which is adhered to the substrate 1, is joined by being melted and integrated, whereby the semiconductor element 3 is hermetically sealed inside a container formed of the base 1 and the lid 2.

The lid 2 is made of an iron alloy such as Kovar metal (Fe-Ni-Co alloy) or 42 alloy (Fe-Ni alloy).
The ingot (lumps) of the Kovar metal or the like is manufactured by forming a predetermined plate shape using a conventionally known metal rolling method and a punching method.

Since the iron alloy constituting the lid 2 is not a brittle material such as alumina ceramics, its thickness is 0.2 mm.
It is not damaged even when the external force is applied. Therefore, even if the thickness of the lid 2 is set to about 0.2 mm and the overall thickness of the package is reduced, the hermetic sealing inside the container can be maintained, and the semiconductor element 3 accommodated in the container can be normally and stably maintained for a long time. It can be activated.

The surface of the cover 2 is made of high melting glass.
When covered with 2a, the high melting point glass 2a serves to electrically insulate the lid 2 which is conductive, and the bonding wire 6 for connecting the electrode of the semiconductor element 3 to the external lead terminal 4 is connected to the lid 2.
Contact, causing a short circuit between the electrodes of the semiconductor element 3, or unnecessary electricity flowing from the outside to the semiconductor element 3,
It is possible to effectively prevent a change in the characteristics of the device. Therefore, in order to operate the semiconductor element 3 stably with high reliability, it is preferable to cover the surface of the lid 2 with the high melting point glass 2a. In this case, as the high melting point glass 2a, for example, lead oxide (PbO) 40.0 to 60.0% by weight, silicon oxide (SiO ₂ ) 20.0 to 40.0% by weight, boron oxide (B ₂ O ₃ )
Glass containing 5.0 to 10.0% by weight, or silicon oxide (Si
O ₂ ) A glass containing 40.0 to 60.0% by weight, barium oxide (BaO) 20.0 to 35.0% by weight, and calcium oxide (CaO) 5.0 to 15.0% by weight has a thermal expansion coefficient close to that of the lid 2. It is preferably used because it allows the cover 2 to be firmly coated. Since these glasses have a high melting point of 600 to 900 ° C., the base 1 and the cover 2 can be sealed with a low-melting glass 5 for sealing. And 7 are heated and melted and bonded, and even if heat for heating and melting the low melting point glass for sealing 5 and 7 is applied, the glass is not melted and the electrical insulation of the lid 2 is maintained. Becomes possible.

The low-melting glass 5 for sealing adhered on the upper surface of the substrate 1 and the low-melting glass 7 for sealing adhered on the lower surface of the lid 2 are each composed of 58.0 to 68.0% by weight of lead oxide. A glass containing 4.0 to 10.0% by weight of boron oxide and 2.0 to 5.0% by weight of silicon oxide and 21.0 to 35.0% by weight of β-eucryptite as a filler. The semiconductor element 3 is hermetically sealed in a container formed by 1 and a lid 2.

The low-melting glasses 5 and 7 for sealing have a coefficient of thermal expansion of 5.5 to 6.0 × 10 ⁻⁶ / ° C., and a coefficient of thermal expansion (6.5 to 7.5 × 10
^-6 / ° C) and the thermal expansion coefficient (4.1 to 5.5 × 10 ^-6 / ° C) of the Kovar metal or iron alloy such as 42 alloy, which constitutes the lid 2. Are bonded by melting and integrating the low-melting glass for sealing 5, 7;
When the semiconductor element 3 is hermetically sealed in a container consisting of the base 1 and the lid 2, the sealing is performed between the low-melting glass 5, 7 which is melted and integrated with the lid 2, and the sealing which is melted and integrated. No large thermal stress is generated between the low-melting glass 5, 7 and the base 1, and as a result, cracks and cracks are generated in the low-melting glass 5, 7 for sealing due to the thermal stress, Lid 2
Does not peel off from the sealing low melting point glass 5, 7.

When the amount of lead oxide is less than 58.0% by weight, the low-melting glass 5 or 7 for sealing has a small coefficient of thermal expansion of the glass, and does not match the thermal expansion of the base 1, and
If the content exceeds 8.0% by weight, the crystallization of the glass progresses, and the hermetic sealing of the container becomes difficult. In addition, the chemical resistance is deteriorated, and the reliability of the hermetic sealing of the container is greatly reduced. %.

If the silicon oxide content is less than 2.0% by weight, crystallization of the glass proceeds, making it difficult to hermetically seal the container.
If it exceeds 5.0% by weight, the coefficient of thermal expansion of the glass becomes so small that it does not match the coefficient of thermal expansion of the substrate 1, so that silicon oxide is limited to the range of 2.0 to 5.0% by weight.

If the content of boron oxide is less than 4.0% by weight, the coefficient of thermal expansion of the glass becomes large and does not match the thermal expansion of the lid, and if it exceeds 10.0% by weight, the chemical resistance of the glass deteriorates and the Boron oxide is limited to the range of 4.0 to 10.0% by weight because the reliability of hermetic sealing is greatly reduced.

If the content of β-eucryptite as a filler is less than 21.0% by weight, the coefficient of thermal expansion of the glass becomes too small to match the thermal expansion of the substrate 1, and if it exceeds 35.0% by weight, the coefficient of thermal expansion of the glass Becomes bigger lid 2
Β-eucryptite is 2
It is limited to the range of 1.0 to 35.0% by weight.

Thus, according to the package for accommodating a semiconductor element of the present invention, the semiconductor element 3 is attached and fixed to the bottom surface of the concave portion 1a of the base 1 via an adhesive, and each electrode of the semiconductor element 3 is externally connected by the bonding wire 6. After connecting to the lead terminal 4, the base 1 and the lid 2 are heated and melted, and the low-melting-point glass 5, 7 for sealing, which is previously adhered to the opposing main surfaces thereof, is joined. By letting
The semiconductor element 3 is hermetically sealed inside a container including the base 1 and the lid 2, thereby completing a semiconductor device as a product.

[0027]

According to the semiconductor device housing package of the present invention, the base is formed of alumina ceramics and the lid is formed of an iron alloy, and the low-melting glass for sealing is formed of a material having a thermal expansion coefficient of the base and the lid. Lead oxide in the middle of the coefficient of thermal expansion 58.0
To 68.0% by weight, 4.0 to 10.0% by weight of boron oxide, 2.0 to 5.0% by weight of silicon oxide, and 21.0 to 35.0% by weight of β-eucryptite as a filler. Are bonded with a low-melting glass for sealing, and when the semiconductor element is hermetically sealed in a container formed of a base and a lid, the space between the lid and the low-melting glass for sealing and between the low-melting glass for sealing and The thermal stress generated between the substrates is extremely small, and as a result, cracks and cracks are generated in the low-melting glass for sealing due to the thermal stress, and the lid is peeled off from the low-melting glass for sealing. Nothing at all, always complete hermetic sealing of the package,
The semiconductor element housed therein can be operated normally and stably for a long period of time.

Further, since the thickness of the lid can be reduced, the overall thickness of the package can be reduced, and the present invention can be applied to a semiconductor device mounted on an information processing device, which has recently become thinner.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an embodiment of a package for housing a semiconductor device according to the present invention;

FIG. 2 is a cross-sectional view showing one embodiment of a conventional package for housing a semiconductor element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Base 2 ... Lid 2a ... High melting point glass 3 ... Semiconductor element 4 ... External lead terminals 5, 7 ... Low melting point glass for sealing

Claims (1)

(57) [Scope of request for utility model registration] A semiconductor device and an external lead terminal to which each electrode of the semiconductor device is connected by a bonding wire are sandwiched between an alumina ceramic base and an iron alloy cover, and glass sealing glass is welded. In a semiconductor element storage package that hermetically seals a semiconductor element therein, the sealing glass is 58.0 to 68.0% by weight of lead oxide,
4.0 to 10.0% by weight of boron oxide, 2.0 to 5.
0% by weight of β-eucryptite as filler
A semiconductor element housing package comprising glass containing 21.0 to 35.0% by weight.