JPS5954287A - 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 crushing device A1 that performs thermal detection.

(b) As shown in Figure 1, a conventional protection device for an output circuit detects the voltage, etc., of an emitter resistor connected in series to each emitter of a complementary output transistor, and makes sure that the voltage, etc., V; is constant. When the temperature exceeds this value, a circuit is activated to cut off the complementary output transistor.
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In such a method, even in a normal state, an excessive current may be generated in the output circuit when a large signal is input, causing a protection circuit to be activated. This means that the protection device using the 'r11 pressure detection method has a response speed of I7! Therefore, we propose a method for detecting the heat generation of the output transistor and operating the protection circuit. The advantage of this method is that the output transistor generates heat (1-4), so the protection circuit works when a large signal is input (this problem can be eliminated).

Its specific structure is shown in FIG. A hybrid 44'', integrated circuit board (
1) A conductive path (2) made of copper foil is provided on the conductive path (2).
), an output 1'l'J transistor (4) is attached via a heat sink (3), and a temperature-sensitive semiconductor element (5) is also attached.
is fixed on the neighboring conductive path (2). However, in such a TtM structure, the heat generated by the output transistor (4) follows the path of heat sink (3) → conductive path (2) → insulating thin layer 02 → metal substrate (11) → disconnected thin layer circle → conductive path (2). Since λL is transmitted to the temperature-sensitive semiconductor element (5), the detection time is long and the thermal resistance is also large, making it difficult to accurately detect the heat generated by the output transistor (4).

(C) Disclosure of the Invention [1] In view of the cut-off point, the present invention provides a protection device for a hybrid integrated circuit using a good temperature detection method.

As shown in FIG. 3, the device for maintaining a hybrid integrated circuit according to the present invention is a hybrid integrated circuit board (first side) provided with a surface (l thin insulating layer 02) of a metal substrate 01 with good thermal conductivity. A desired conductive path (2) is provided on the second conductive path (2), and a heat sink (
3) through which the output transistor (11) is provided, and the insulating N layer (I2) near the output transistor (4) is removed (-
2. After 1tl l, the temperature-sensitive semiconductor element (5) is fixed on the substrate (11). The heat generation of the output transistor (4) is detected by the temperature-sensitive semiconductor element (5), and the current of the output circuit is It is configured to block.

(B) Embodiment The hybrid integrated circuit board (1) is formed by covering the surface of a metal base with good thermal conductivity such as aluminum with an insulating thin layer (12) such as aluminum oxide produced by anodic oxidation. . Such a hybrid integrated circuit board (1) has excellent heat dissipation and is therefore ideal for incorporating an output circuit.

On the hybrid integrated circuit board (1), conductive paths (2) made of foil are formed in a desired pattern by etching.

An output transistor (4) is fixed on the conductive path (2) via a heat sink (3). In addition, the insulating thin layer (12) near the output transistor (4) is ground with an end mill to expose the substrate (substrate), and the temperature-sensitive semiconductor element (
5) is fixed with silver paste. As the temperature-sensitive semiconductor element (5), a planar type transistor, a silicon diode, or the like is used. l) N-junction length 2m
This is because the temperature coefficient of V/p is used.

The heat generated by the output transistor (4) is generated by the temperature-sensitive semiconductor element (5).
The output is detected by the transistor (4), and its output works to cut off the current flowing through the output transistor (4). Specifically, a relay (force) is inserted into the power supply line between the output transistor (4) and the first stage of its driver, and the output of the temperature-sensitive semiconductor element (5) is used to connect this relay (force) to the power line between the output transistor (4) and the first stage of its driver. r.

Fig. 4 shows a more specific protection device (1〆1゛).As the temperature-sensitive semiconductor element (5), the I) N P l-transistor is used once a month, and the pace of the PNP) transistor is also -No-' (H, JE, voltage divided by resistors R7 and R2 is 191 constant (, j, biased according to the protection operating temperature). Due to the temperature rise of the output transistor (4) I) NI) ) Pace emitter voltage V of the transistor, 1. When the voltage decreases to below the set voltage, the PNP transistor becomes conductive and the relay (7) is cut off, cutting off the current of the output transistor (4+(J).

(e) Effect According to the present invention, heat generation due to excessive current of the output transistor (4) (4) is detected by the temperature-sensitive semiconductor element (5) [7
), there is a slight delay until overcurrent is detected, and when a large signal is momentarily input, 1111 (:に;That's not it) can prevent overprotection.

Further, since the temperature-sensitive semiconductor element (5) is directly fixed to the substrate (11), heat generation of the output transistor (4) can be detected quickly and protection can be reliably performed.

Furthermore, the conventionally used high-wattage cement resistor is not required, and the protection device can be greatly simplified, contributing to integration.

[Brief explanation of the drawing]

No. 1N is a circuit diagram explaining the conventional example 'X i + S1', FIG. 2 is a cross-sectional view explaining the conventional structure, No. 31\1 is a cross-sectional view explaining the present invention in detail, and FIG. 4 is a specific example of the present invention. t'
15) is a circuit diagram illustrating the protective device a. Explanation of main drawing numbers (1)...Hybrid integrated circuit board, (,2)...4'
j1 (j path, (3)... heat sink, (4)...
- Output transistor, (5)...temperature-sensitive semiconductor element.

Claims (1)

[Claims] 1. A desired conductive path is provided on a hybrid integrated circuit board having a thin insulating layer on the surface of a metal substrate with good thermal conductivity. , remove the RR layer in the vicinity of the output semiconductor element and place the temperature-sensitive semiconductor element on the exposed metal substrate surface. A protection device f'f for a hybrid integrated circuit, characterized in that the temperature sensing half 2jj is detected by the dead element and the current in the output circuit is cut off.