JPS594146A - Package for semiconductor device - Google Patents

Abstract

PURPOSE:To enable to prevent the production of a parasitic capacity by placing a dielectric substrate and an electric terminal base on the same plane, thereby eliminating the stepwise diffeence of both. CONSTITUTION:An electric terminal 4 has a dielectric base 4A which has the same thickness as a dielectric substrate 3, and a electric piece 4B which is integrated with the base 4A provided in the vicinity of the laminated part 67 of a metallized film of the base 4A, and placed fixedly on the same surface as the surface, to which the substrate 3 is secured. The substrate 3 and the terminal 4 are provided on the same surface of a metal base 1, and since there is no stepwise difference therebetween, no parasitic capacity is produced. Accordingly, it can exhibit excellent high frequency characteristics even in the frequency equal to or higher than Ku band.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a semiconductor device (1) that has a pseudo-coaxial line and a strip line and is suitable for use in an ultra-high frequency band.

In recent years, semiconductor devices such as GaAs-FETs and ultra-small, high-performance microwave amplifier circuits using these devices have been realized, and at the same time, packages that accommodate these devices, circuits, etc. have also been developed. The internal dimensions of the package are extremely small, 6x6x2 (■l), and the applicable frequency is high-performance, extending to the Ku band.

Fig. 1 is a cut-away slope view of the main part of the conventional example, Fig. 2 is a front view of the main part, and Fig. 3 is a cut-away side view of the main part. is an electrical terminal, 41 is an alumina base forming the electrical terminal 4, and 4B is an electrical terminal 4.
The alumina piece body 5 constituting the is a laminated part of a metallized film, 6.7 is a strip line, 8 is a strip line formed on a sapphire plate, 9 is a gold ribbon connecting the strip line 7 and the strip line 9, 10 indicates each level difference.

The thickness of the sapphire plate 3 in this package is 0.3
(n), on the upper surface of which a (2) 50 [Ω] strip line 8 of an amplifier circuit is formed.

Also, electric terminal 41,1, thickness 0.6 [weight], length 1
A pattern of metallized film is formed using a low resistivity tungsten base 1 on the base center of the [drink], and a piece body with a thickness of 0.6 (mm) and a length of 0.5 Cx is formed on the base. Laminate the old metallized film and plate the non-laminated parts of the metallized film with gold to a resistance of 50 CΩ.
- Lip lines 6 and 7 are formed, and a metallized film is formed on the entire side periphery. The electrical terminal 4 is fitted into a hole or notch formed in the base 1 and the frame 2, and is fixed via a metallized film formed on the side periphery. With this configuration, the portion of the electrical terminal 4 where the base body 4A and the piece body 4B are laminated is surrounded by the base 1 and the frame 2. It can be seen as a pseudo-coaxial line in which the outer conductor and the laminated portion 5 of the metallized film are the inner conductor, and the base body 4A and the bridge body 4B are the dielectric bodies. In addition, the pseudo-coaxial line has a configuration in which a series of I-IJ tubular lines 6.7 are connected on both sides of the pseudo-coaxial line.

(3) Although the thickness of the sapphire plate 3 and the base 48 of the electric terminal 4 are different, since the base 1 is cut to form an appropriate step 10, the sapphire plate 3 and the base 48 of the electric terminal 4 are different in thickness. When the upper surfaces of the sapphire plate 3 and the substrate 4 are arranged on the same surface, the strip line 7 and the strip line 17 are disposed on the same surface.
It is easy to combine N with a ribbon.

This package has excellent characteristics, with extremely low insertion loss and electric [1:standing wave ratio] at frequencies up to I(ui4').

However, this is up to the KI+ band, and when the frequency exceeds this, the disturbance of the electric field generated at the step IO cannot be ignored, and as shown in Fig. 4,
This means that a bias capacitor 12 is inserted into the 50 [Ω] strip line 11, and power reflection and power loss occur at the step 10.

The base 4A of the electrical terminal 4 has a radius of 0.6 [11] that is equivalent to that of a standard package used for semiconductor elements such as FETs.
Furthermore, the sapphire plate 3 has a thickness of 0.3 (4) [1 dia] due to electrical requirements and is a standard product.

Purpose of the Invention The present invention provides a method for preventing the generation of parasitic capacitance due to the step difference.
In addition, the present invention attempts to provide a package that does not cause power reflection or power loss even at frequencies above the Ku band.

Embodiment of the Invention FIGS. 5 and 6 are a cross-sectional side view and an OR-cut front view of an embodiment of the present invention, and the same parts as those explained with respect to FIGS. 1 to 3 are designated by the same symbols. It is an instruction.

In this embodiment, the thickness of the electrical terminal 4 to the base 4 is →
Since it is the same as that of the J-fire plate 3, and therefore the step 10 of the base 1 as seen in FIG. 3 is unnecessary, the fourth
There is no room for the parasitic cavities 12 seen in the figure to occur.

The thickness of the substrate 4 is 0.3, which is the same as that of the sapphire plate 3.
[■], the thickness of the related piece 4B constituting the pseudo-coaxial line must also be 0.3 [+n]. When the piece 413 becomes thinner, the height of the package (5) from the base center becomes lower, which is useful when connecting a plurality of packages. That is, in that case, the packages are arranged in parallel and abutted so that the electrical terminals 4 face each other, and bonding is performed between the strip wires 1736.6. The interval between 2 is only 0. 5
(mi), it is not an easy task to insert a jig for bonding there. Therefore, as described above, the reduced height above the base 4^ greatly facilitates the bonding operation.

By the way, the characteristic impedance of the eccentric axis line and the strip line 6, 7 at the electric terminal 4 is determined by the width of the laminated portion 5 (inner conductor) of the metallized film, the width of the strip line 6.7, the base body 4A, and the bridge body. It depends on the width of 4B.

Now, assuming that the thickness of the base body 4^ and the piece body 4B is 0.3 (mm), the width of the laminated portion 5 of the metallized film is approximately 0.1 mm in order to obtain a characteristic impedance of 50 [Ω].
5 (mt) and the width of the strip lines 6 and 7 is approximately (6) 0.2 (m+i). However, if these widths are narrowed, the loss of microwave power t1 increases, so they cannot be made narrower unconditionally. In a commonly used device, the width of the laminate portion 5 should be 0.2 (m), and the width of the strip line 6.7 should be 0.25 (mm).
] In order to maintain the characteristic impedance of I am doing it.

Effect of the invention The package of the present invention has a metal frame and an eye.

A metal base that houses and fixes a dielectric substrate having at least a strip line on its surface, a laminate part of a metallized film that becomes the inner conductor of the pseudo-coaxial line on the surface, and a strip line extending from both ends of the laminate part. 7) The dielectric body has a dielectric base formed and has the same thickness as the dielectric substrate, and a dielectric piece provided in the vicinity of the laminated portion of the metallized film on the base and integrated with the base 7). Since the structure is such that the electrical terminals are placed and fixed on the same surface on which the dielectric substrate is fixed, the dielectric substrate and the base of the electrical terminals are on the same surface of the metal base. Since it is on a plane and there is no step between them, no parasitic capacitance occurs. Therefore, it exhibits excellent high frequency characteristics even at frequencies below the Ku band, and is effective not only for ultrahigh frequency linear integrated circuit devices but also for ultrahigh speed digital integrated circuit devices. As the base that connects the electrical terminals becomes thinner, the piece also becomes thinner, so the height above the base becomes lower as a PASO gauge, making it difficult to connect multiple PA-7 cages. It also has the effect of making the work easier.

[Brief explanation of the drawing]

Fig. 1 is a cut-away slope view of the main part of the conventional example, Fig. 2 is a front view of the main part, Fig. 3 is a cut-away side view of the main part, Fig. 4 is an equivalent circuit diagram, and Fig. 5 is a cut-away side view of the main part.
The figure is a cutaway side view of the main part of an embodiment of the present invention, and FIG. 6 is a cutaway front view of the main part. In the figure, 1 is a copper base, 2 is a copper frame, 3 is a supia board, 4 is an electrical terminal, 4A is an alumina base that makes up the electrical terminal (8) 4, and 4B is an alumina piece that makes up the electrical terminal 4. body, 5 is the laminated part of the metallized film,
6.7 is a strip line, 8 is a strip line formed on a Sapphire board, and 9 is a gold ribbon connecting the strip line 7 and the strip line 9. Patent applicant Fujido Co., Ltd. Agent Patent attorney Tools Kugobe (3 others) (9) Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] a metal base having a metal frame and housing and fixing a dielectric substrate having at least a strip line on its surface;
A dielectric substrate having a laminated portion of a metallized film serving as an inner conductor of a pseudo-coaxial line on its surface and a strip line extending from both ends of the laminated portion and having the same thickness as the dielectric substrate; A dielectric piece body provided near the laminated portion of the metallized film and integrated with the base body, and an electric terminal placed and fixed on the same surface as the surface to which the dielectric substrate is fixed. A pancage for semiconductor devices characterized by the following features: