JPS59161845A - Containing package for semiconductor device - Google Patents

Abstract

PURPOSE:To improve the high frequency isolation between the input and output by a method wherein a buffer material which absorbs the stress caused by the difference of coefficients of thermal expansion is split in the direction of the extension of input-output terminals, and then an isolation member electrically connected to a package substrate is inserted to the split end surfaces, when said buffer material is interposed between the package substrate made of a metal and a ceramic package mounted thereon. CONSTITUTION:A semiconductor element mounting base 4 is provided on the package substrate 1 made of a metal, and the ceramic package 3 having an aperture corresponding to the mounting base 4, the input terminal 5 and the output terminal 6 projecting out from the aperture is provided, thus being decided as the titled package. In this constitution, the buffer member 12 made of an Mo plate, etc. is provided under the mounting base 4 as an underlay. At this time, this member 12 is split, and the isolation member 13 put in electric contact with the substrate 1 is interposed between the produced split end surfaces. Thus, a package of good isolation between input-output terminals even in a high frequency band is obtained.

Description

[Detailed description of the invention] (al Technical field of invention The present invention relates to improvements in housing containers for semiconductor devices.

(bl) Prior Art and Problems Containers for semiconductor devices, especially high-frequency, high-power semiconductor devices, have good heat dissipation properties so as to satisfy the required high-frequency characteristics and to quickly release the heat generated inside the device to the outside. In order to provide the
1 is a plan view of a conventional housing container for a semiconductor device (hereinafter simply referred to as a package), and bl is a cross-sectional view thereof.

In the figure, 1 is a package base made of oxygen-free copper (Cu), 2 is a molybdenum (Mo) plate, 3 is an envelope made of ceramic, and 4 is a mounting table for a semiconductor element formed by protruding the package base 1. , 5 and 6 are input and output terminals. When actually using this, the semiconductor element (
For example, a GaAs-FET (not shown) is glued on the mounting table 4, and thin metal wires are bonded to connect the input terminal 5 and output terminal 6 to the corresponding electrode band (the G
In the aAs-FET, the gate electrode and the drain electrode are electrically connected. After that, a lid (not shown) made of a metal plate or the like is adhered to the upper surface of the ceramic envelope 3 to hermetically seal the semiconductor element.

In the above structure, the molybdenum plate 2 is a buffer interposed between the package base 1 and the ceramic envelope 3 in order to prevent the occurrence of the above-mentioned crank, since sled molybdenum has a coefficient of thermal expansion close to that of ceramic. It is a material.

However, since the surface of the molybdenum plate 2 has poor wettability with the silver source, which is an adhesive, the adhesion between the package substrate 1 and the two molybdenum plates is not necessarily good. Therefore, the molybdenum plate 2 is not grounded in terms of high frequencies,
Feedback occurs between the input terminal 5 and the output terminal 6 via the stray capacitance between the two terminal leads 15°6 and the molybdenum plate 2,
Therefore, there was a problem that the isolation between the input and output terminals deteriorated. Figure 2 is an equivalent circuit diagram between the input and output terminals of the package, where c, , C2 are the input and output terminals 5
, 6 and the stray capacitance L, , L2 between the molybdenum plate 2 represents the inductance of the molybdenum plate 2 itself.

tc+ OBJECTS OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and provide a container for housing semiconductor devices with good high-frequency isolation between the input and output of the package.

(d) Structure of the Invention A feature of the present invention is that heat generated between the package base and the ceramic envelope is disposed between the package base made of metal and the ceramic envelope attached to the upper surface of the package base. In a structure in which a buffer material for stress caused by a difference in expansion coefficients is interposed, the buffer material is divided into at least two parts in the direction in which the input/output terminal extends, and the buffer material is divided into at least two pieces, and there is a gap between opposing divided end faces of the buffer material. A separation member electrically connected to the package base is interposed therein.

(al　Embodiments of the invention An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3(a), (bl is a plan view and a sectional view of this embodiment, FIG. 4 is an equivalent circuit diagram between input and output terminals of the above embodiment,
5(a) to (C1) are exploded perspective views of the present embodiment shown in FIG. 3. FIG.

As shown in FIG. 5, in this embodiment, the molybdenum plate 2 of the buffer member is an annular integral piece in the conventional package, but it is divided into two pieces as shown in FIG. 5(b). These two molybdenum plates I2 are placed on the end face of the package base 1 of the mounting table 4 in the direction in which the input/output terminals are arranged, as shown in FIG. The separation member 13 and the pancage base 1 are opposed to each other with a separation member 13 formed by protruding the base 1 interposed therebetween.
Glue using a silver source. Here, the thicknesses of the two molybdenum plates 12 and the separation member 13 are selected so that the upper surfaces of the molybdenum plates 12 and the separation member 13 form substantially the same plane.

Then, on top of that, a ceramic envelope 3 shown in Fig. 5fa) is placed.
Glue.

The package of this embodiment configured in this way (Fig. 3 (
In al and (see bl), a molybdenum plate serving as a buffer material is divided into two parts, and a separation member 13 is placed between the opposing end surfaces of the two parts.
is interposed, the two molybdenum plates 12
The lines of electric force between the opposing end faces of are cut. Therefore, in this embodiment, the inductances L1 and L2 of the molybdenum plate 2 itself in the equivalent circuit shown in FIG. 2 are divided, and the space between them is in an open state. FIG. 4 shows an equivalent circuit of the package of this embodiment. In the same figure, L, /,
L 2/ is the inductance of the two molybdenum plates 12 themselves. As described above, in this embodiment, since the input and output terminals are cut off at high frequency, feedback between the input and output terminals is prevented, and isolation is improved.

Furthermore, since the separation member 13 is interposed and bonded between the end faces of the molybdenum plate 12 divided into two parts as described above,
Since the shape is exactly the same as the conventional package, after sealing, sufficient airtightness can be obtained like the conventional package, and there is no problem.

Although the above embodiment has been described with reference to an example in which the cushioning material is divided into 2f[lil], the number of divisions is not limited to two, and may be three or more.

In addition, the cushioning materials are the package base 1 and the ceramic cylinder envelope 3.
Any material may be used as long as it can absorb the stress caused by the difference in coefficient of thermal expansion between the material and the material, so it is not necessary to be limited to molybdenum plates.

(fl) As described in detail, the present invention provides a housing container for semiconductor devices with good isolation between input and output terminals even in a high frequency band.

[Brief explanation of the drawing]

FIG. 1 is a plan view and a sectional view showing the main parts of a conventional storage container for a semiconductor device, FIG. 2 is an equivalent circuit diagram between input and output terminals of the conventional storage container, and FIG. 3 is an embodiment of the present invention. FIG. 4 is an equivalent circuit diagram between the input and output terminals of the embodiment, and FIG. 5 is an exploded perspective view of the embodiment. In the figure, 1 is a package base, 2 and 12 are cushioning materials, 3 is a ceramic envelope, 4 is a mounting table for semiconductor elements, and 5
and 6 indicate input and output terminals, and 13 indicates a separation member. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] Between the package base made of metal and the envelope made of ceramic attached to the upper surface of the package base, there is a buffer for stress caused by the difference in coefficient of thermal expansion between the package base and the envelope made of ceramic. In the structure in which a material is interposed, the buffer material is divided into at least two parts in the direction in which the input/output terminal extends, and the opposing divided end faces of the buffer material are electrically connected to the pan cage base. 1. A storage container for a semiconductor device, characterized in that a separating member is interposed therein.