JP3534082B2 - On-chip temperature detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-chip temperature detecting device, capable of quickly detecting temperature with high accuracy, while increase in the number of element manufacturing processes and chip area are suppressed, with no separate temperature detecting means required. SOLUTION: A very small constant current Ib2, which does not turn on a current control type element 4, flows in a base, when the element 4 is off, and the temperature characteristics of a forward voltage Vb2 of a base-emitter diode is utilized to detect a temperature; no separate temperature detecting means is required; and while increase in the number of element manufacturing processes and chip area are suppressed, to enable quick detection of the temperature by on-chip method with high accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current control type element for driving an inductive load or the like so that the temperature of the current control type element can be detected accurately and promptly so that the entire system can operate safely. Technology.

[0002]

2. Description of the Related Art For the purpose of more accurately and quickly detecting the temperature of a semiconductor device or the like, it is increasingly necessary to form a temperature detecting means on a power semiconductor device and on-chip. Figure 11
(A) is a diagram showing a structure described in Japanese Patent Application Laid-Open No. 7-66402 as the above conventional example. In FIG. 11A, an element (power element) 12 that operates by being applied with power
1 and a temperature detecting means (diode or temperature sensor) 12 for detecting the temperature of the element 121 which has generated heat by applying the electric power.
3 are formed on the semiconductor substrate 120, and the same semiconductor substrate 1
A control circuit 122 for driving the element 121 is also mounted on the device 20, and forms a power IC device as a whole. In the case of this example, by forming the temperature detecting means 123 with a thin film on the surface of polysilicon or the like, it is possible to electrically completely separate it from the element 121 to which power is applied and to operate, and the on-chip Accurate temperature detection can be performed quickly. As another conventional technique,
There is one described in JP-A-9-36356.
This is a semiconductor substrate of a bipolar semiconductor element (IGBT) with temperature detection means (diode) formed as a separate region,
This is a method of detecting the temperature by utilizing the temperature dependence of the forward voltage. That is, the forward voltage is measured to detect the temperature when the gate of the bipolar semiconductor element is off or on. In this method, stable temperature detection is realized by measuring the interference with the bipolar semiconductor element in a "constant state".

[0003]

In the prior art as described above, it is necessary to provide a temperature detection exclusive area and a separation area in addition to the power element which is operated by the application of electric power. There is a problem that the area increases. Further, when using a current control type element which originally does not use planar type polysilicon as a power element as disclosed in Japanese Patent Laid-Open No. 6-252408, the temperature of a diode or the like formed by a pn junction of polysilicon as described above. Since the detection means is provided, the number of processes not required in the original semiconductor element formation process is increased, the product cost is increased, and the aluminum wiring above the temperature detection element has a step, or the characteristic of the element is not proper. There was a problem in that Further, there is also a problem that other wires cannot be tightly laid due to the wiring wires for the temperature detecting element. For example, in FIG.
The vertical current control type power element shown in FIG. 1B will be described as an example. A power element 7 is formed on a semiconductor substrate 6, and a plurality of bonding pads 8 connected to an emitter electrode are formed on the surface of the power element 7. A plurality of bonding pads 9 connected to the base electrode are formed. The collector electrode corresponds to the back surface side of the semiconductor substrate 6. Further, the temperature detecting element 130 is formed with two dedicated bonding pads 131. If it is a current control element that handles a large current,
It is necessary to extend a large number of emitter wires 12 and base wires 13 to the bonding pad very densely.
However, if the dedicated area 130 for temperature detection exists as in the example of FIG. 11B, the dedicated bonding pad 1
It is necessary to stretch the wire 134 dedicated to temperature detection from 31 and there is a problem that the emitter wire 12 and the base wire 13 cannot be tightly stretched around the wire.
Similarly, the existence of the temperature detection dedicated area deteriorates the original symmetry of the element arrangement, which causes a layout problem that the influence on the element characteristics cannot be avoided.

The present invention has been made in order to solve the problems of the prior art as described above, and it is not necessary to separately provide a temperature detecting means, and the on-state can be achieved while suppressing the increase of the element manufacturing process and the increase of the chip area. It is an object of the present invention to provide an on-chip temperature detection device capable of highly accurate and quick temperature detection by a chip.

[0005]

In order to achieve the above object, the present invention is constructed as described in the claims. That is, in the invention described in claim 1, when the current control type element is off, a minute constant current to the extent that the current control type element does not turn on is made to flow to the base, and the forward direction of the base-emitter diode is increased. The temperature is detected by utilizing the temperature characteristic of the voltage.

According to the invention of claim 2,
When a small constant current is applied to the base of a current-controlled device that is off, the forward voltage of the base-emitter diode is the voltage at which the current-controlled device turns on (usually 0.6
.About.0.7V) or less.

Further, in the invention described in claim 3,
Forward voltage Vb between the base and emitter of the current control element
e is a function of the base current and the temperature T, and the constant current Ib is proportional to exp (q · Vbe / nkT), and n is 1.
It is configured to be used within the above range of real numbers.

Further, in the invention described in claim 4,
It is configured to detect a temperature by applying a constant base current in a pulse shape while the current control element is off.

In the invention described in claim 5,
In a current control element used for a drive element such as an inverter, a constant base current in a pulse shape during a period in which one current control element is on and the other current control element is off. Is applied to detect the temperature.

According to the invention of claim 6,
In a current control element used for a drive element such as an inverter, in a period in which one current control element is on, and after a period in which the other current control element is off,
While the former current control element is off (while the return current flows in the latter current control element or the return diode connected in parallel), a constant base current is applied to the former current control element in a pulsed manner. It is configured to flow and detect temperature.

In the invention described in claim 7,
While the current-controlled element is off at the drive timing of the inverter, etc., a plurality of temperature data detected by applying a constant base current in a pulse form are continuously sampled, and the average value of the detected temperatures is calculated. Is configured as follows.

Further, in the invention described in claim 8,
At the drive timing of an inverter or the like, a constant base current flowing in a pulse shape is made to flow to a current-controlled element that is turned off a plurality of times for each off, and the average value of the detected temperature data is calculated for each off. Is configured as follows.

[0013]

According to the first aspect of the present invention, it is not necessary to prepare a separate temperature detecting means, and the on-chip precision and rapid temperature control can be performed while suppressing an increase in the element manufacturing process and an increase in the chip area. The effect that detection is possible is obtained.

Further, in the invention described in claim 2,
When a small constant current is applied to the base of a current-controlled device that is off, the forward voltage of the base-emitter diode is the voltage at which the current-controlled device turns on (usually 0.6
.About.0.7 V) or less, the effect of claim 1 can be obtained while maintaining the OFF state sufficiently and satisfying the basic function as a switch.

Further, in the invention described in claim 3,
Since the current control type element can be operated in a region where the current amplification factor is relatively small, the collector current should be 3 to the rated value.
It is possible to obtain an effect that it is easy to suppress the current value to a low value of 4 digits or less.

Further, in the invention described in claim 4,
An effect that it is possible to suppress unnecessary power consumption at the time of temperature detection is obtained.

In the invention described in claim 5,
The effect that the temperature can be stably detected even when applied to an inverter or the like is obtained.

Further, in the invention described in claim 6,
When applied to an inverter or the like, it is possible to obtain an effect that temperature can be detected while preventing disturbance due to the return current even during the period when the return current is flowing.

According to the invention of claim 7,
It is possible to obtain the effect that the temperature can be detected without the influence of noise during measurement.

In the invention described in claim 8,
It is possible to increase the number of samplings within a certain period of time, and it is possible to obtain the effect of enabling temperature detection with higher noise resistance performance.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 is a circuit diagram showing an essential part of the first embodiment of the present invention. Figure 1
The circuit shown in (1) uses a current control type element (for example, a power bipolar power transistor) 4 as a switch for driving the resistive load 3. Here, the collector terminal of the current control type element 4 is connected to the power source 1 via the resistive load 2.
And the emitter terminal is connected to the ground potential 2. A base driving circuit is connected to the base terminal of the current control element 4, but it is omitted in FIG. The details of the base drive circuit will be described later with reference to FIG.

The basic operation of the switch will be described. When the current control element 4 is turned on, a desired large current is supplied to the base terminal as the current Ib1 indicated by the solid arrow. When the current control type element 4 is turned on, a desired current I
c1 is supplied from the power supply 1 to the resistive load 3. The current Ic1 does not flow while the current control element 4 is off. In the present invention, a small base current Ib2 which is constant in this off state is intentionally supplied to the base terminal of the current control element 4. As will be described later, the minute base current Ib2 is the base current Ib during the normal ON state.
The value is set to be smaller than b1 and the collector current (leakage current) Ic2 at this time is set to be about 3 to 4 digits smaller than the collector current Ic1 in the normal ON state.

The base-emitter voltage Vbe (forward-direction voltage of the pn junction between the base-emitter) of the current control element 4 is a function of the base current Ib and the temperature T. Therefore, if the base current Ib is kept constant, the temperature can be estimated by utilizing the fact that the rate of change of the base-emitter voltage Vbe with respect to temperature is constant. Here, the characteristic configuration of the present invention is that a constant minute base current Ib2 is passed through the current control element 4 in the off state and the magnitude of the base-emitter voltage Vbe2 at this time is set to the current control element. The voltage at which 4 turns on (usually 0.6
It is a low value with respect to ~ 0.7V).

According to the above structure, the current control element 4 is not completely turned on, and a minute leak current Ic2 flows between the collector and the emitter. here,
The level of the leak current Ic2 is 3 digits to the magnitude of the main current Ic1 when the resistive load 3 is driven.
It should be as low as 4 digits. Drive current I of resistive load 3
If the error level affected by c1 for control is considered to be about 1% or more, the above-mentioned leak current Ic2 is smaller by one digit or more, so the effect can be ignored.

As described above, according to the first embodiment, a constant minute current is applied to the base of the current control element 4 in the off state, and the base-emitter voltage at that time is detected, On-chip temperature detection is possible without providing special temperature detection means.

FIG. 2 shows the base of the current control element.
It is a figure which shows the relationship between emitter-to-emitter voltage Vbe, base current Ib, and collector current Ic. In FIG. 2, for a general current control type element, the horizontal axis represents the base-emitter voltage Vbe, and the vertical axis represents the base current Ib and the collector current Ic on a log scale.

It is assumed that the temperature has a constant value T (for example, room temperature). In the characteristics of Ic and Ib, In (Ib), In (Ic) and In (Ic) with respect to changes in Vbe in a wide range in the middle.
Respectively change linearly, and Ib and Ic are respectively proportional to exp (q · Vbe / kT). Also, Vb
In the region 5 where e is very small, Ib becomes exp (q · Vbe
/ NkT). Note that n is a real number of 1 or more, q is the amount of electron charge, k is the Boltzmann constant, and T is temperature.

Here, in the present invention, the constant minute current applied to the base of the current control type element 4 in the off state is such that the resulting Vbe is sufficiently lower than the voltage at which the current control type element 4 is turned on. . For example, the on-voltage is 0.6
In the case of ~ 0.7V, it may be set to 0.5V or less. For the purpose of only detecting the temperature, in FIG. 2, Vbe is Ib and Ic is exp (q.Vbe
Ib is exp (q
The area may be proportional to (Vbe / nkT). However, as a result, when a certain constant current Ib flows, a collector Ic larger than that flows, so that the collector current Ic is 3 to 4 digits or less with respect to the main current driving the load. Limited to the range of Considering this point, Ib is more exp (q · V) than the current amplification factor of the current control element in the region where Ib and Ic are proportional to exp (q · Vbe / kT).
Since the current amplification factor in the region proportional to (be / nkT) is smaller, setting the measurement point in this region has the effect of making it easier to suppress the collector current Ic to a small value.

FIG. 3 is a diagram showing the timing of temperature detection together with the on / off operation of the current control type element 4 in FIG. The horizontal axis of FIG. 3 represents time. Further, on the vertical axis, (a) represents the on / off state of the current control type element 4, in which the low level is turned off and the high level is turned on. (B) and (c) show the timing of temperature detection, and (b) shows the case where temperature detection is performed once during the period when the current control type element 4 is off.
(C) shows the case where temperature detection is performed multiple times.

In this embodiment, as shown in FIG. 3, the temperature is detected in a pulsed manner. Since a power supply voltage is applied between the collector and the emitter of the current control element 4 in the off state, even if it is a minute current, if it is constantly applied,
Power consumption increases, and self-heating cannot be ignored.
Also, the loss will increase. Therefore, in this embodiment, the temperature is detected in a pulsed manner to solve the above problem. Although there is a possibility that noise is added to the detected voltage in one-time temperature detection, noise can be removed from the detected temperature by performing temperature detection multiple times and calculating the average value of the detected temperature. It becomes possible to do. In this case, since temperature detection is performed every ON / OFF cycle of the current control type element 4, even if a certain number of detection times is calculated,
It can sufficiently cope with changes in temperature.

FIG. 4 is a plan layout diagram for explaining the layout advantage in this embodiment. In FIG. 4, as in the conventional example shown in FIG. 11B, a vertical current control element will be described as an example. In FIG. 4, a current control type element (power element) 7 is formed on a semiconductor substrate 6,
A plurality of bonding pads 8 connected to the emitter electrodes and a plurality of bonding pads 9 connected to the base electrodes are formed on the surface of the current control element 7. The collector electrode corresponds to the back surface side of the semiconductor substrate 6. The temperature detecting element and the dedicated bonding pad for the temperature detecting element in the conventional example are not formed.

It is obvious from FIG. 4 that the present embodiment realizes on-chip temperature detection, but there is no need for a special temperature detecting means area or a dedicated wire associated therewith. When it is used as an element for driving a current, there is an effect that wires can be struck very densely and a symmetrical layout can be obtained.

A more specific circuit structure of this embodiment will be described below. FIG. 5 is a circuit diagram showing an example of the base drive circuit in this embodiment. In FIG. 5, a switch (made up of a MOS transistor) 16 for switching on / off is provided at the base terminal of the current control type element 4.
17 is connected. One end of the switch 16 is connected to a power supply 23 for supplying a base current. Also, switch 17
Is connected to the emitter terminal of the current control type element 4. Resistor 1 inserted in series with switches 16 and 17
Reference numerals 9 and 20 are resistors for determining the current value when the current control element 4 is turned on and off. An ON / OFF command signal is sent from the CPU 14 serving as a controller to the control circuit 1.
Input to 5. When the current control element 4 is normally turned on, the control circuit 15 outputs signals for turning on the switch 16 and turning off the switch 17, respectively. In this example, the switch 16 is a pMOS and the switch 17 is an nMO.
Since it is S, a low level signal is applied to the gates of the switches 16 and 17. On the contrary, when the current control type element 4 is turned off, the control circuit 15 outputs signals for turning off the switch 16 and turning on the switch 17, respectively. In this example, a high level signal is applied to the gates of the switches 16 and 17. The power supply 23 and the power supply 24 are described separately, but they may be the same.

In order to detect the temperature in the above state, the switch 17 is turned off by the control circuit 15 and the switch 1
Turn on 8. Then, a minute constant current determined by the power supply 24 and the resistor 21 is applied to the base of the current control element 4. In this state, the base-emitter voltage Vbe of the current control type element 4 is detected by the potential detecting means 22 and the potential information is transmitted to the control circuit 15. Here, the potential detecting means 22 can be specifically configured by an amplifier circuit, a comparator circuit, or the like that compares a predetermined reference voltage with the detected voltage and inverts the output. In addition, various methods are possible.

The temperature can be detected by the above operation. In an actual system, the protection operation is performed after the temperature is detected. For example, when the temperature exceeds a predetermined value, an abnormal signal is sent from the control circuit 15 to the CPU 14, a stop signal is sent from the CPU 14 that has judged the state to the control circuit 15, and the switches 16 and 17 are controlled accordingly. The protection operation is performed so that the current control type element 4 is turned off. For details on the protection operation, refer to "" Transistor Technology Special-Introduction to Practical Power Electronics ",
pp 99-102 CQ Publishers ".

Next, the division of the heat generating power chip and other parts in FIG. 5 will be described. In the present invention, the heat generating power chip (current control type element 4) and the temperature detecting portion are the same components, and correspond to the portion surrounded by the broken line rectangle in FIG. For it,
Other drive circuit parts are separate from the part surrounded by the broken line rectangle, and in terms of the internal configuration of the power module,
It can be formed in a thermally separated portion (for example, a second floor or an upper stage). Therefore, it is possible to operate the drive circuit and the detection circuit (the control circuit 15 and each switch portion) at a temperature independent of the temperatures of the power chip and the temperature detection unit.

Further, since the power chip itself needs a high breakdown voltage operation, it is necessary to use an expensive epitaxial substrate for the semiconductor substrate. From the overall configuration, the manufacturing cost per unit area of this power chip is relatively large. Is getting higher. Therefore, providing a dedicated area for temperature detection on the same substrate as the power chip as in the conventional example causes a high cost. In this embodiment, the structure of the power chip itself is the same as that before the addition of the on-chip temperature detecting function, so that the cost increase can be suppressed.

Regarding the drive circuit portion of FIG. 5, although a circuit for temperature detection is newly added, since it is a circuit that operates with a low breakdown voltage, the manufacturing cost per unit area of the semiconductor chip is relatively large. Since it is cheaper, there is little impact on cost increase. If the overall circuit scale is large,
It can be said that the effect of cost increase due to the increase in the number of circuits in this embodiment is even smaller.

FIG. 6 is a diagram showing a concrete configuration example of the voltage between the base and the emitter used for temperature detection. The current control type element is a so-called power bipolar
Although it may be a transistor, here, Japanese Patent Application No. 5-3 is the same current control type device and has an advantage of a large current amplification factor.
The semiconductor device disclosed in Japanese Patent No. 3419 will be described as an example. A detailed description of the structure and operation of each part of the device will be omitted, and a basic cell of the device will be described based on the cross-sectional perspective view of FIG.

In FIG. 6, the gate region 28 corresponds to the base, and the source region 29 corresponds to the emitter.
The interface between the p-type gate region 28 and the n-type epitaxial region 27 corresponds to the pn junction between the base and the emitter. In an actual device, this gate region exists evenly throughout. Therefore, the pn junctions used for temperature detection are widely distributed over the entire surface of the power chip, and local temperature rise can be detected sufficiently quickly.

(Second Embodiment) FIG. 7 is a circuit diagram showing a second embodiment of the present invention. The circuit of FIG. 7 has two current control type elements 34 between the power supply voltage 1 and the ground potential 2.
And 4 are connected in series, and these two current-controlled elements 3
This is a circuit in which an inductive load 37 is connected in parallel between 4 and 4, and a relationship between a switching element and a load for one leg in a so-called inverter is shown. Current control element 34
A free wheeling diode 35 is connected in parallel with the current control element 4 and a free wheeling diode 36 is connected in parallel with the current control element 4.

The basic operation of the inverter will be described. While one of the current control type elements 34 and 4 is off, another current control type element repeatedly turns on and off,
The desired current is supplied to the inductive load 37. The freewheeling current flows through the freewheeling diode while both elements are off.

In FIG. 7, it is assumed that the current control element 34 is repeatedly turned on and off and the current control element 4 is turned off. When the current Ib3 indicated by the solid arrow flows through the base terminal of the current control element 34, the current control element 34 turns on, and the drive current Ic3 indicated by the thick arrow in the drawing flows to the inductive load 3. When the current control type element 34 is turned off, the return current flows through the return diode 35. By changing the ON / OFF ratio of the current control type element 34 (PWM control), it is possible to flow a current of a desired magnitude as a whole. In this state, the base terminal of the current control element 4 is normally not supplied with the base current, and the current control element 4 is off. In the present invention, in this state, a small constant base current Ib2 is intentionally supplied to the base terminal of the current control element 4. At this time, the base-emitter voltage Vbe2 of the current control type element 4 is equal to the base current I
It is a function of b2 and temperature T. If the base current Ib2 is set to a constant value, it is possible to estimate the temperature by utilizing the fact that the rate of change of Vbe2 with respect to the temperature is constant. This operation principle is basically the same as that of the first embodiment. Similar to the first embodiment, the base current Ib2 is supplied to the current-controlled element 4 which is off, and the magnitude of Vbe2 is the voltage at which the current-controlled element 4 is turned on (usually 0.6 to
The value is sufficiently low with respect to 0.7V). By using such a method, the current control element 4 is not completely turned on, and a minute leak current Ic2 flows between the collector and the emitter.

Here, with respect to the magnitude of the main current Ic3 driving the inductive load 37, the leakage current Ic
The level of 2 is 3 to 4 digits lower. If the error level of the drive current Ic3 of the inductive load 37, which is affected by control, is considered to be about 1% or more, the leak current Ic
2 can be considered small enough.

The operation characteristic of the second embodiment is that the inductive load 37 is driven,
There is a timing when the upper and lower current control type elements 34 and 4 are turned off at the same time, and at that timing, the return current flows through the return diode. Therefore, the timing of temperature detection is characterized. The situation is shown in FIG.

FIG. 8 is a timing chart similar to that of FIG. 3, in which the horizontal axis shows time and the vertical axis shows the state of each signal. First, the waveform of (a) shows the on / off state of the current control element 4, and the high level is on and the low level is off. The waveform (e) shows the on / off state of the current control type element 34. Similarly, the high level is turned on and the low level is turned off. This timing chart is an example of the case where the inductive load 37 is driven in the direction of Ic3 in FIG. 7, and the waveforms of the current control type elements 34 and 4 are exchanged when the current is driven in the opposite direction. In the waveform of (a), the current control element 34 is repeatedly turned on and off a plurality of times while the current control element 4 is off. In FIG. 8, it is turned on and off five times for the sake of convenience, but in practice, several hundred to several 10,000 times may be switched. (F) and (g) show the timing of temperature detection, and (f) is the period during which the current control type element 4 is turned off once, and the current control type element 34 is turned on. The case where the temperature detection is performed once in the state is shown. (G) shows the case where the temperature detection is performed for each state in which the current control element 4 is off and the current control element 34 is turned on a plurality of times.

In FIG. 8, even when the current-controlled element 4 is off, the current-controlled element 34 is off or in a transient state (pulse rising or falling portion). The temperature is not estimated. By taking such a timing, there is a special effect that the temperature can be stably detected even when applied to an inverter or the like that drives an inductive load.

FIG. 9 shows the temperature detection timing.
An example such as shown in can be considered. In FIG. 9, (h) is the temperature detection timing, and the temperature detection is performed many times in one period in which the current control element 4 is off and the current control element 34 is on. is there. By performing such temperature detection, more sampling can be performed in a short time, and by calculating the average value of the temperature data, it is possible to perform temperature detection with high noise resistance.

(Third Embodiment) A third embodiment of the present invention will be described. The configuration of the current control element and the like is the same as that of the second embodiment shown in FIG. The feature of this embodiment lies in the temperature detection timing and the selection of the current control type element used for temperature detection. Hereinafter, description will be given with reference to FIG.

FIG. 10 is a timing chart similar to that of FIG. In the figure, (a) shows the on / off state of the current control type element 4, and (e) shows the on / off state of the current control type element 34. (I) shows the timing of temperature detection in the current control type element 34. When the current control element 34 shifts from the on state to the off state during the period in which the current control element 4 continues to be turned off, both current control elements 34 and 4 are turned off, so that the current flows to the inductive load 37. The free-wheeling current flows through the free-wheeling diode 36 as if it were supplementing the main current Ic3. In this state, the collector potential 38 of the current control type element 4 becomes lower than the ground potential 2, so that a reverse bias is applied between the collector and the emitter of the current control type element 4 and temperature detection based on the principle of the present invention is not performed. Not suitable. Therefore, in this embodiment, the temperature is detected during this period by using the current control type element 34 which is turned off on the opposite side. That is, the current Ib2 indicated by the broken line arrow is supplied to the base terminal of the current control element 34 as a pulsed minute current at the timing as shown in (i) of FIG. 10 to detect the temperature. The basic principle of temperature detection is the same as in the first embodiment.

By performing such temperature detection, it becomes possible to detect the temperature even during the period when the reflux current flows when the inductive load is driven by the inverter or the like. In this case, it is possible to detect the temperature of any one of the two semiconductor chips forming the upper and lower arms at any timing, and considering that the two semiconductor chips are arranged relatively close to each other, the accuracy is sufficiently high. It is possible to detect temperature.

Further, FIG. 10 (j) similarly shows the timing of temperature detection in the current control type element 34. In (j), the current control element 4 is 1
The current control element 34 is used to detect the temperature a plurality of times during the period of turning off, and the noise resistance can be further improved by increasing the number of temperature detections within a certain time as in the other embodiments. It enables high temperature estimation.

As described above, in the present invention,
Since a certain minute base current is applied to the current-controlled element that is off and the temperature is detected by detecting Vbe in the off state, there is no need to create a special temperature detection area or temperature detection device. It is possible to realize the on-chip temperature detection with high accuracy and speed, without increasing the chip area, preventing the cost from increasing, and not affecting the original characteristics of the element.

[Brief description of drawings]

FIG. 1 is a basic circuit configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing electrical characteristics of the current control element according to the first embodiment of the present invention.

FIG. 3 is a timing chart in the first embodiment of the present invention.

FIG. 4 is a plan layout view around a power chip according to the first embodiment of the present invention.

FIG. 5 is a base drive circuit diagram in the first embodiment of the present invention.

FIG. 6 is a device cross-sectional perspective view of the current control element according to the first embodiment of the present invention.

FIG. 7 is a basic circuit configuration diagram showing a second embodiment of the present invention.

FIG. 8 is a timing chart in the second embodiment of the present invention.

FIG. 9 is another timing chart according to the second embodiment of the present invention.

FIG. 10 is a timing chart in the third embodiment of the present invention.

11A and 11B are diagrams showing a conventional example, in which FIG. 11A is a plan layout diagram in the conventional example, and FIG. 11B is a plan layout diagram around a power chip in the conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Power supply 2 ... Ground potential 3 ... Resistive load 4 ... Current control type element 5 ... Region where Ib is proportional to exp (q.Vbe / nkT) 6 ... Semiconductor substrate 7 ... Vertical current control type element 8 ... Emitter Bonding pad 9 ... Base bonding pad 10 ... Emitter wiring 11 ... Base wiring 12 ... Emitter bonding wire 13 ... Base bonding wire 14 ... CPU 15 ... Control circuit 16, 17, 18 ... Switch 19, 20, 2
DESCRIPTION OF SYMBOLS 1 ... Resistor 22 ... Voltage detection part 23 ... Power supply 24 ... Power supply 25 ... Drain electrode 26 ... Drain n + region 27 ... N-type epitaxial region 28 ... P-type gate region 29 ... N + -type source region 30 ... P + -type polysilicon 31 ... Gate Insulating film 32 ... Trench gate region 33 ... Channel region 34 ... Current control type element 35 ... Reflux diode 36 ... Reflux diode 37 ... Inductive load 38 ... Collector potential 120 of current control element 4 ... Semiconductor substrate 121 ... Power element Area 123 ... Temperature detection dedicated area 122 ... Control circuit section 130 ... Temperature detection dedicated element 131 ... Temperature detection element dedicated bonding pad 132 ... Anode electrode 133 ... Cathode electrode 134 ... Temperature detection bonding wire Ib1 ... Base current during normal operation Ib2 ... Micro base current Ic1 for temperature detection ... Normal The collector current Ic2 ... temperature at the time of detecting the leakage current Ic3 ... drive current Vbe2 ... temperature detection at the time of the base-emitter voltage at the time of work

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-9-36356 (JP, A) JP-A-10-41510 (JP, A) JP-A-8-111524 (JP, A) JP-A-6- 291323 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 29/78 657

Claims (8)

(57) [Claims] 1. A current control type semiconductor device having a base terminal, a collector terminal and an emitter terminal, and a diode having a pn junction between the base terminal and the emitter terminal, and a control signal applied to the base terminal. When off,
A first means for flowing a constant base current smaller than the base current in which the current control element is normally turned on to the base terminal, and a constant base current smaller than the base current in the normal on state. Second means for detecting the temperature of the current-controlled element based on the forward voltage between the base and emitter of the current-controlled element in the flowing state; pn
An on-chip temperature detection device characterized by performing temperature detection by using temperature dependence of a forward voltage of a diode due to a junction. 2. The first means is characterized in that a forward voltage between a base and an emitter of the current control type element in a state where a constant base current smaller than a base current which is in the normal ON state is flowing, The temperature detection device according to claim 1, wherein the temperature control device is set to be equal to or lower than a voltage at which the current control type element is turned on. 3. When the constant base current flowing when the control signal is off is Ib and the forward voltage between the base terminal and the emitter terminal is Vbe, the Vbe is the Ib and the temperature T.
Where q is an electron charge amount and k is a Boltzmann constant, Ib is exp (q · Vbe / nk
It is a small current in the range proportional to T), and n is 1
The on-chip temperature detection device according to claim 1 or 2, wherein the on-chip temperature detection device is a real number as described above. 4. The first means is characterized in that a constant base current flowing when the control signal is off is made to flow in a pulsed manner to intermittently detect the temperature. The on-chip temperature detection device according to any one of 1. 5. There are two said current control type elements, the emitter terminal of one current control type element and the collector terminal of the other current control type element are connected in series, and an inductive load or the like is connected to said connection point. Is connected in parallel and drives the inductive load or the like by turning on / off the two current control type elements, in a period in which one of the current control type elements continues to turn on, and While the other current-controlled element is off, a constant base current smaller than the base current at which the current-controlled element is normally turned on is applied to the base terminal of the off-current-controlled element. The on-chip temperature detection device according to claim 4, wherein the temperature detection is performed intermittently by flowing in a pulsed manner. 6. The former current control type element is turned off continuously after a period in which the one current control type element is on and the other current control type element is off. Thereby, the diode connected in parallel to the latter current-controlled element, or the base terminal of the former current-controlled element that is turned off during the period when the return current flows in the latter current-controlled element itself, The on-chip according to claim 5, wherein the temperature control device intermittently detects the temperature by causing a constant base current smaller than a base current in which the current control type element is normally turned on to flow in a pulse shape. Temperature detection device. 7. A constant base current flowing in a pulse shape is made to flow a plurality of times in a current control type element which is turned off within a predetermined time, temperature is detected for each of the base currents, and an average value within the predetermined time is obtained. The on-chip temperature detecting device according to claim 5 or 6, characterized in that. 8. A constant base current flowing in a pulsed manner is made to flow a plurality of times in each of the off-state current control type elements for each off, and temperature detection is performed for each of the off times, and an average is obtained for each off. The on-chip temperature detecting device according to claim 5, wherein the value is obtained.