JPS5954288A - Device for protecting hybrid integrated circuit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to a protection device for a hybrid integrated circuit, and particularly to a preservation device that performs thermal detection.

(Ron) As shown in Figure 1, a conventional output circuit purulent preservation device detects the voltage of the emitter resistor connected in series to each emitter of the complementary output transistor, and the voltage is constant. If this value is exceeded, a protection circuit operates and shuts off the complementary output transistor.

With this method, the normal state is 77! ? Nevertheless, there is a possibility that an excessive 71i current flows into the output circuit when the dog No. 1 is input, causing the protection SIt circuit to operate. This is due to the voltage detection method.
This is due to the fact that the response bed jW is extremely fast.

Therefore, we propose a method to detect the heat generation of the output transistor and activate the protection circuit. According to this method, the heat generated by the output transistor can be efficiently reduced, thereby eliminating the inconvenience and inconvenience of the protection circuit operating when a large signal is input.

Its specific structure is shown in FIG. A conductive path (2) made of copper foil is provided on a hybrid integrated circuit board (1)-J2 in which a thin insulating layer (1) such as an aluminum oxide film is provided on the surface of a metal substrate (11) such as aluminum. (2) An output transistor (4) is fixed on the top via a heat sink (3), and a temperature-sensitive semiconductor element (5) in the center is fixed with a neighboring conductor '71 on the path (2). Nakara j till + Il (
;In the report, the heat generated by the output transistor (4) is caused by the heat sink (3)→n? Since the information is transmitted to the temperature-sensitive semiconductor element (5) through the path (2) -> insulating thin layer (12) -> metal substrate (11) -> insulating thin layer (12) -> conductive path (2), the detection time is also shortened. Long (
In addition, the thermal resistance is large (therefore, the heat generation of the output transistor (4) cannot be accurately detected).

(C) Disclosure of the Invention The present invention has been thoroughly reviewed and evaluated, and provides four methods for protecting hybrid integrated circuits:
fi+.

As shown in FIG.
・On the surface of 1tsu'+'j a)be11)? Edge lamina (12
) Mixed Tr'Z Hayabusa image 1111 road near il: board i
A desired conductive path (2) is provided on the ll, and a -outer conductive path (2)
An output transistor (4)' is provided at 7 through a human sink (3) to J2, and a temperature-sensitive semiconductor element (5) is fixed on the heat sink (3) to reduce the heat generated by the output transistor (4). It is configured so that the current of the output circuit is cut off by detecting the current value (5).

2) Embodiment The hybrid integrated circuit board (1) is formed by covering a highly thermally conductive metal substrate (marked surface) with an insulating thin layer (12) such as aluminum oxide produced by anodic oxidation. The hybrid integrated circuit board (1) has excellent heat dissipation properties, so it is suitable for incorporating an output circuit.

A conductive path (2) made of copper foil is etched into a desired pattern on the hybrid integrated circuit board (1)-J. A. The output transistor (4) is placed on the Q heat sink (3).
) and the temperature-sensitive semiconductor element (5) are fixed. The shape of the heat sink (3) may be a flat 4' (1, λ) shape as shown in FIG. 3, or a stepped shape as shown in FIG. The latter is advantageous in that it reduces the height difference with the conductive path (2) when bonding is performed. A silicon planar transistor, a silicon diode, or the like is used as the temperature-sensitive semiconductor element (5). The voltage of the PN junction is 2mV'/
This is because the Ait fB-coefficient of C is used.

The heat generated by the output transistor (4) is generated by the temperature-sensitive semiconductor element (5).
The output is immediately detected by the output l transistor (4
) works to cut off the current flowing through the Specifically, a relay (force) is inserted into the power line between the output transistor (4) and the first stage of its driver, and the output of the temperature-sensitive semiconductor element (5) shuts off this relay (7). A more specific drawing device is shown.PN is used as the temperature-sensitive semiconductor element (5).
P) Using a transistor, PNP) Is the base of the transistor Zener? The lj pressure is divided by resistors R1 and R2, and the voltage is biased in accordance with a predetermined protection operating temperature.

As the temperature of the output transistor (4) rises, the base-emitter voltage of the PNP transistor (V) increases, 1. When the voltage decreases and becomes below the set voltage, the PNP transistor becomes conductive and the relay (
The power is cut off and the current in the output transistors (4) (4) is cut off.

(E) Effect According to the present invention, heat generation due to excessive current in the output transistors (4) (4) is detected by the temperature-sensitive semiconductor element (5), so there is a slight delay until the excessive current is detected. There is no risk of it working when a large signal is input (overprotection can be prevented).

Furthermore, since the temperature-sensitive semiconductor element (5) is directly fixed to the heat sink (3), the heat generated by the output transistor (4) can be detected quickly and accurately, allowing highly accurate maintenance. It eliminates the need for a high-wattage cement resistor, greatly simplifies the protection device, and contributes to integration.

[Brief explanation of the drawing]

Figure 1 is a circuit 1''/.1 explaining a conventional example, Figure 2 is a cross-sectional view explaining the main Q main conventional structure, Figures 3 and 4 are cross-sectional views explaining the structure of the present invention, Figure 5 The figure is a circuit 1 illustrating a protection device embodying the present invention.0 Explanation of main figure numbers (1)...Hybrid integrated circuit board, (2)...Conducting path, (3) ... Heat sink, (4) ... Output transistor, (5) ... Temperature-sensitive semiconductor element. Applicant Sanyo Electric Co., Ltd. Name

Claims (1)

[Claims] 1. A desired conductive path is provided on a hybrid integrated circuit board.In a hybrid integrated circuit having an output circuit in which an output semiconductor element is provided on the conductive path via a heat sink, a temperature-sensitive semiconductor i< element is placed on the heat sink. 1. A protection device for a hybrid integrated circuit, characterized in that heat generation of said output semiconductor element is detected by said temperature-sensitive semiconductor element to cut off current in an output circuit.