JPH0543515Y2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to a hybrid integrated circuit device incorporating a switching circuit, and particularly to a hybrid integrated circuit device that suppresses noise generated by the switching circuit.

(b) Conventional technology Switching regulators are widely incorporated into various electronic devices because they can efficiently realize compact and lightweight power supply circuits. However, since the switching operation uses high voltage and large current, there is a problem in that noise is generated from the power supply circuit.

For example, in order to reduce such noise,
As shown in Publication No. 49369 (HO2M 3/28), the voltage of the switching frequency component is
Prevents conduction to the power supply. That is, the mounting bracket of the switching transistor is connected to one terminal of the smoothing capacitor with a wire having low impedance at the switching frequency.

However, when a power supply circuit is constructed using discrete elements as described above, effective noise countermeasures cannot be expected because the components are distributed and arranged on a printed circuit board or a heat sink.

(c) Problems to be Solved by the Invention The present invention has been made in view of this point, and its object is to realize a hybrid integrated circuit device that suppresses the noise generated by the switching circuit.

(d) Means for Solving the Problems A hybrid integrated circuit device incorporating a switching circuit according to the present invention consists of a highly thermally conductive metal substrate whose surface is insulated, a desired switching circuit formed on the substrate, and a switching circuit. and an external lead for connection with an external circuit, and a core made of a magnetic material is attached to at least the external lead to which the switching frequency is applied.

(E) Embodiment The hybrid integrated circuit device used in the present invention, as shown in FIG.
a thin layer 2 of aluminum oxide (Al ₂ O ₃ ) is provided on top;
A predetermined conductive path 3, a resistor 4, a power transistor 5, etc. are attached on this thin film 2 using well-known hybrid integrated circuit technology to form a switching circuit such as a switching regulator. Further, an external lead 6 is provided on one side of the metal substrate 1, and is connected to an external circuit such as a capacitor, an input/output terminal, etc.

The feature of the present invention lies in the core 7 made of a magnetic material.
The core 7 is made of solidified ferrite powder and has a ring shape.
It is formed into a cylindrical shape or the like and is attached to the external lead 6 as in the embodiment described below.

In FIGS. 3A and 3B, the cylindrical core 7
is prepared and selectively penetrated through the external lead 6 to which the switching frequency is applied to suppress noise. The core 7 is fixed with one end embedded in a molded resin 8.

In FIGS. 4A and 4B, cores 7 and 7' having an uneven half-split shape corresponding to the shape of the external lead 6 are prepared, and the external lead 6 is passed through the recess to form a closed magnetic circuit. There is. The cores 7, 7' surround all the external leads 6, and one end of the cores 7, 7' is embedded in a molded resin 8 and fixed.

In FIG. 5A, a core 7 which is integrally formed with the above-mentioned half-split shape is used.

In FIGS. 6A and B, the loop-shaped core 7
All the external leads 6 are arranged in the loop, and one end of the core 7 is embedded in the molded resin 8 and fixed.

As shown in FIG. 2, the hybrid integrated circuit device described above is installed in an aluminum shield box 9 made of a chassis or the like via an insulating film 10, so that the metal substrate 1 acts as an electrostatic shield and suppresses noise. This makes it an extremely useful structure. Furthermore, since the external lead 6 is provided with the core 7, noise can be suppressed at the location closest to the noise source, making it possible to keep the noise level extremely low.

(f) Effects of the invention According to the invention, the metal substrate 1 and the core 7 are used to effectively suppress noise with an extremely simple structure. Furthermore, by suppressing the noise level, it becomes possible to actively incorporate a hybrid integrated circuit device incorporating a switching circuit into electronic equipment, contributing to the reduction in size and weight of electronic equipment.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view illustrating the hybrid integrated circuit device of the present invention, Fig. 2 is a side view illustrating the mounting structure of the hybrid integrated circuit device of the present invention to electronic equipment, Fig. 3A, Fig. 3B , Figure 4A, Figure 4B, Figure 5A,
FIGS. 6A and 6B are a side view and a cross-sectional view illustrating the core of the hybrid integrated circuit device of the present invention. Explanation of main figure numbers: 1 is a metal substrate, 6 is an external lead, and 7 is a core.

Claims (1)

[Scope of claim for utility model registration] A metal substrate with good thermal conductivity whose surface is insulated, a desired switching circuit formed on the substrate, an external lead for connecting the circuit to an external circuit, and one end of which is attached to a molded resin. In a hybrid integrated circuit including a core made of a loop-shaped magnetic material embedded and fixed and arranged so as to surround all the external leads, the hybrid integrated circuit is connected to the core through an insulating film arranged in an aluminum shield box. 1. A hybrid integrated circuit device incorporating a switching circuit, characterized in that the switching circuit is installed in the device.