JPH0710495Y2 - Semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a semiconductor device, and more particularly to a structure of a ceramic package.

[Conventional technology]

FIG. 3 is a sectional view showing the structure in the vicinity of the lead terminal joint of a conventional ceramic package of this type.

In this figure, reference numeral 1 denotes beryllia ceramic, and a metallized portion 5 for enabling mounting of the transistor chip 9 and the like is formed on the upper surface of the filter. Reference numeral 2 is an alumina ceramic, which is provided with an input / output metallized portion 5 metallized in an appropriate pattern for bonding the connection thin wire 10, to which a lead terminal 6 is brazed by a brazing material 7. A frame ceramic 3 is fixed on the alumina ceramic 2, and a cap 4 is hermetically sealed with a solder material 8 thereon. The alumina ceramic 2 and the frame ceramic 3 are joined together by a laminate, and the alumina ceramic 2 and the beryllia ceramic 1 are joined together by brazing (not shown).

In the above structure, the frame ceramic 3 is laminated on the alumina ceramic 2 having the metallized portion 5 as the metallizing pattern for connecting the input / output pattern and the lead terminal 6 in the package cavity, and after firing, the transistor chip 9 and the like are formed. After bonding the transistor chip 9 and the connection thin wire 10 to the ceramic header of the laminated structure in which the alumina ceramic 2 is brazed (not shown) to the beryllia ceramic 1 having the metallized portion 5 for bonding, the cap 4 is soldered. The material 8 was fixed and hermetically sealed.

[Problems to be solved by the device]

In the conventional semiconductor device having the above-described structure, the cap 4 is soldered or sealed with an adhesive directly on the alumina ceramic 2 having the bonding pattern of the connection thin wire 10 and the fixing pattern of the lead terminal 6 connected thereto. In such a case, the input / output pattern is bonded with the metallic solder material 8, and the electrical performance inherent in the device cannot be fully exhibited.

Further, even when a resin is used for fixing the cap 4, a portion where the metallized portion 5 is applied and a portion where the metallized portion 5 is not applied are mixed in a portion where the alumina ceramic 2 is joined to the cap 4, and a flat surface is formed due to unevenness of metallizing. In order to perform the airtight sealing with a very coarse degree, it is necessary to further laminate the frame ceramics 3 that serve as the sealing flange, which causes a problem that the package structure becomes complicated and large. It was

The present invention has been made in order to solve the above-mentioned conventional problems, and airtight sealing can be performed without using a frame ceramic as a sealing flange and with a reduced number of laminate layers. The purpose is to obtain a semiconductor device.

[Means for Solving the Problems]

A semiconductor device according to the present invention is one in which an inner surface of an alumina ceramic is coated with metallizing or other conductive material and filled, a metallized portion is led out to the surface opposite to the upper surface of the alumina ceramic, and a lead terminal is fixed to this portion. Is.

[Action]

In the semiconductor device according to the present invention, a through hole is formed in the alumina ceramic, the lead terminal is led out to the back surface of the alumina ceramic through the through hole, and the cap is joined to the metallized portion on the upper surface. Since it is led out to the outside of the package, it is not necessary to stack a sealing flange, and airtight sealing can be performed with solder or the like.

〔Example〕

 The invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of the semiconductor device of the present invention.
FIG. 4 is a cross-sectional view of the vicinity of a lead terminal joint portion of the ceramic package.

In FIG. 1, the same reference numerals as those in FIG. 3 indicate the same components, and 2a is a through hole formed in the alumina ceramic 2, and metallized portions 5a are formed on the front surface and the back surface of the alumina ceramic 2 through the through hole 2a. Is derived,
The lead terminal 6 is fixed by the brazing material 7 to the metallized portion 5a led out on the back surface. Therefore, the lead terminal 6
Will be derived outside the package. Further, the cap 4 is made of solder material 8 and hermetically sealed on the upper surface of the alumina ceramic 2 to a metallized portion 5b which is separated from the metallized portion 5a.

Next, the operation will be described.

A metallized portion 5a as an input / output pattern metallized on the alumina ceramic 2 is electrically led to the outside through a through hole 2a provided in the alumina ceramic 2. At that time, the through hole 2a is filled with the brazing material 7 for fixing the metallized portion 5a or the lead terminal 6, and the airtightness of this portion is maintained. Since the lead terminals 6 are fixed to the back surface of the alumina ceramic 2 in this manner, the surface of the cap 4 fixed to the alumina ceramic 2 with the solder material 8 or the like is extremely smooth in order to maintain the airtightness inside the package. It is possible to prevent the occurrence of leakage failure.

In the above embodiment, the lead terminal 6 is provided in the horizontal direction, but the same effect can be obtained by providing the pin-shaped external terminal 6a through the through hole 2a as shown in FIG. This is effective when surface mounting is performed by an automatic machine or the like.

In the above embodiment, the case where the beryllia ceramic 1 is used is shown, but other ceramics such as alumina and aluminum nitride may be used.

[Effect of device]

As described above, in the present invention, the through hole is provided in the alumina ceramic, the metallized portion is led out on the surface opposite to the metallized portion on the upper surface of the alumina ceramic, and the lead terminal is fixed. There is an effect that defects can be prevented and the package outer shape can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an essential part showing an embodiment of the semiconductor device of the present invention, FIG. 2 is a cross-sectional view of an essential part of another embodiment of the present invention, and FIG. Is. In the figure, 1 is beryllia ceramic, 2 is alumina ceramic, 2a is through hole, 4 is cap, 5,5a, 5b.
Is a metallized portion, 6 is a lead terminal, 7 is a brazing material, 8 is a solder material, and 9 is a transistor chip. The same reference numerals in each drawing indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] 1. An alumina ceramic having a semiconductor chip mounted on a metallized portion formed on the upper surface of the ceramic, wire-bonded to the semiconductor chip, and provided with a metallized portion for leading out lead terminals on the upper surface of the ceramic. In the semiconductor device in which the cap is hermetically sealed on the alumina ceramic, a through hole is provided in the alumina ceramic, the metallized portion is led out to the surface opposite to the metallized portion on the upper surface of the alumina ceramic, and the lead terminal is provided. A semiconductor device characterized by being fixed.