JPH01196858A - Transistor - Google Patents

Abstract

PURPOSE:To detect the temperature of the junction section of a transistor accurately including transient thermal fluctuation by incorporating a diode for detecting a temperature into the same chip as the transistor. CONSTITUTION:A P-type base layer 2 into an N-type silicon substrate 1 and an N-type emitter layer 3 into the layer 2 are formed. A collector electrode 4 onto the underside of a chip, a base electrode 6 brought into contact with the base layer 2 into all opening section in an oxide film 5 on the top face of the chip and an emitter electrode 7 brought into contact with the emitter layer 3 are shaped. A P-type anode region 8 is formed adjacent to the base layer 2 in the chip, and a P-N junction is shaped between the anode region 8 and the substrate 1. Currents are made to flow between a terminal A and a terminal C, and the forward voltage of a diode 13 for detecting a temperature positioned between the terminals A and C is measured. Accordingly, the temperature of the junction section of a transistor is detected precisely including the case of transient thermal fluctuation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a transistor whose junction temperature can be easily detected.

[Conventional technology]

The current rating of a semiconductor device is usually determined by knowing the thermal resistance between the junction and the case, and by ensuring that the junction does not reach the maximum allowable temperature due to the loss that occurs during energization.

For this purpose, it is necessary to detect the junction temperature. In diodes, silices, etc., the junction temperature can be detected using the temperature characteristics of forward voltage. In a transistor, there is a voltage between the base and emitter as a characteristic corresponding to the forward voltage of the diode, but since its temperature characteristic is affected by the conditions of the base circuit, it is not used to detect the junction temperature. As shown in the equivalent circuits of FIGS. 3 and 3, it is common to place a thermistor 12 or a diode 13 near the chip of the transistor 11 to estimate the junction temperature of the transistor 11.

[Invention tries to solve! I! Title]

However, there is a temperature difference between the temperature of a temperature detection sensor such as the thermistor 12 or diode 13 and the junction temperature of the transistor 11, and in particular, due to the relationship between thermal time constants, the estimated junction temperature The drawback was that there was a large error in temperature.

An object of the present invention is to provide a transistor that can accurately detect junction temperature even in the case of transient thermal fluctuations.

[Means to solve the problem]

In order to solve the above problem 01, the transistor of the present invention has a PN junction separate from the junction forming the transistor in one chip, and the PN junction is provided with a terminal for passing forward current. do.

[Effect]

The forward voltage drop of the diode due to the PN junction formed separately in the transistor chip changes depending on the chip temperature that rises due to the operation of the transistor. The junction temperature can be detected.

〔Example〕

FIG. 1 shows a transistor chip according to an embodiment of the present invention, in which a P-type base N2 is formed on an N-type silicon substrate 1, an N-type emitter N3 is formed therein, and the original part of the substrate 1 serves as a collector. This is a particle bipolar transistor structure. A collector electrode 14 on the bottom surface of the chip, a base electrode 6 in contact with the second layer 2 in the opening of the oxide film 5 on the top surface,
An emitter electrode 7 is provided in contact with the N layer 3, and is connected to a collector terminal 01, a base terminal B, and an emitter terminal E, respectively. Furthermore, this transistor chip has
A P-type anode region 8 is also formed adjacent to the base layer 2 and forms a PN junction with the N-type substrate 1. The P calendar 8 can be formed in the same process as the second layer 2. An anode electrode 9 contacts this PI3 and is connected to an anode terminal A. That is, as shown in the equivalent circuit of FIG.
3 is formed in the same chip 10 as the transistor 11,
It has a collector terminal C and an anode terminal A.

The junction temperature of the transistor in Figure 1 is between terminal A and terminal C.
By passing a current between them and measuring the forward voltage of the temperature detection diode 13 existing between them, it is possible to determine that the temperature of the PN junction between the anode region C and the collector region 1 is approximately equal to the junction temperature of the transistor. The junction temperature of the transistor at that point can be detected. Note that in this case, the size of PH8 is limited because the current flowing through the diode does not affect the temperature of the chip.

〔Effect of the invention〕

According to the present invention, by incorporating a temperature detection diode in the same chip as the transistor without increasing the number of steps, the junction temperature of the transistor can be accurately detected, even in the case of transient thermal fluctuations. Furthermore, since there is no need to connect the transistor to an external temperature detection sensor, it is possible to downsize the device, reduce the number of parts, and reduce costs.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a transistor chip according to an embodiment of the present invention, FIGS. 2 and 3 are equivalent circuit diagrams showing an example of a conventional transistor junction temperature detection method, and FIG. 4 is a cross-sectional view of a transistor chip according to an embodiment of the present invention. It is an equivalent circuit diagram of an example. 1: Collector, 2: Base, 3: Emitter, 8: Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1) A transistor characterized in that it has a PN junction separate from the junction forming the transistor in one chip, and the PN junction is provided with a terminal for passing forward current.