JP3509623B2 - Temperature detection structure of semiconductor switch element chip, temperature detection device, and semiconductor relay - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature detecting structure for a semiconductor switch element chip, a temperature detecting device, and a semiconductor relay. More specifically, it is possible to detect the temperature of the chip formed on the chip on which the semiconductor switch element is formed. The present invention relates to a temperature detecting structure, a temperature detecting device for detecting the temperature of a chip on which a semiconductor switch element is formed, and a semiconductor relay for turning off the semiconductor switch element in the on state based on the temperature of the chip on which the semiconductor switch element is formed.

[0002]

2. Description of the Related Art Conventionally, as this type of semiconductor relay,
It has been proposed that a temperature detecting element is provided in the vicinity of a semiconductor switching element connected between relay output terminals, and the semiconductor switching element is turned off by a signal from the temperature detecting element (for example, Japanese Patent Laid-Open No. 10-233669). ).
In this semiconductor relay, negative temperature
A diode having a voltage characteristic is used, and when the voltage drop of this diode becomes low, the semiconductor switch element is turned off. That is, when a large current flows through the semiconductor switching element and its temperature rises, the voltage drop of the diode decreases and the semiconductor switching element is turned off. By adopting this structure, thermal destruction of the semiconductor switch element due to overcurrent flowing through the semiconductor switch element is prevented.

[0003]

However, such a semiconductor relay has a problem that it may be turned off even when a large current does not flow through the semiconductor switching element. The voltage drop of the diode as the temperature detecting element is about 0.7 V, and its temperature-voltage characteristic is -1.5 to
The negative characteristic is −2.4 [mV / ° C.]. Therefore,
Since the temperature detection structure using such a diode has a low output voltage level, the temperature detection structure is easily affected by external noise, which causes a malfunction due to noise.

One of the objects of the temperature detecting structure of the semiconductor switch element of the present invention is to provide a temperature detecting structure which is less affected by noise. Another object of the temperature detecting structure of the semiconductor switch element of the present invention is to reduce the size increase of the chip caused by providing the temperature detecting structure. The temperature detecting device for a semiconductor switch element of the present invention is intended to more accurately measure the temperature of a chip on which a semiconductor switch element is formed without being affected by noise, in addition to the purpose of the temperature detecting structure of the semiconductor switch element of the present invention described above. One of the purposes is to detect. Another object of the semiconductor relay of the present invention is to prevent a malfunction caused by noise, in addition to the above-mentioned object of the temperature detecting device for a semiconductor switch element of the present invention.

[0005]

MEANS FOR SOLVING THE PROBLEMS AND OPERATIONS AND EFFECTS THEREOF The present invention provides a temperature detecting structure for a semiconductor switch element chip, a temperature detecting device, and a semiconductor relay, in order to achieve at least a part of the above objects, the following means are provided. I took it.

The temperature detecting structure of the semiconductor switching element of the present invention detects the temperature of the chip on which the semiconductor switching element is formed.
Temperature to detect and generate voltage based on the detected temperature
The temperature detection structure is formed on a chip on which the semiconductor switch element is formed, and has a temperature-voltage characteristic element having a predetermined voltage characteristic with respect to a change in temperature, and the temperature-voltage characteristic element. Connected , said temperature-voltage characteristic
A low-pass filter for removing high-frequency components of the voltage signal generated in the element , wherein the low-pass filter is the temperature controller.
And a resistance connected in series with the temperature-voltage characteristic element and the temperature-voltage characteristic element.
It consists of a characteristic element and a capacitor connected in parallel.
The main point is that the filter is

In the temperature detecting structure of the semiconductor switching element of the present invention, the low-pass filter connected to the temperature-voltage characteristic element removes high frequency noise. As a result, a predetermined voltage characteristic can be taken out from the temperature-voltage characteristic element with respect to an accurate temperature change. Also, if you do this,
The filter can be easily configured in the group.

In such a temperature detecting structure for a semiconductor switch element of the present invention, the chip is the temperature detecting structure.
Bonding for electrical connection of the output signal of the
Is provided on the upper surface of the chip, and the capacitor is
It may be formed under the bonding pad . By doing this, the overall size can be reduced.
Wear.

In such a temperature detecting structure for a semiconductor switching element of the present invention, the temperature-voltage characteristic element is a diode.
The temperature-voltage characteristics described above can also be used.
The element can also be a resistor.

The temperature of the semiconductor switching device of the present invention as described above
In the degree detection structure, the semiconductor switch element has an electric field
Is an effect transistor or a bipolar transistor
It can also be one.

In the temperature detecting structure for a semiconductor switch element according to the present invention, the capacitor is a semiconductor oxide film.
A first electrode formed of polysilicon and
A second electrode formed by high-concentration doping on the substrate.
It is also possible to have a structure of sandwiching by. Well
In addition, such a temperature detection structure of the semiconductor switch element of the present invention is
In the fabrication, the semiconductor switch element is a field effect transistor.
The semiconductor oxide film is a field effect transistor.
Part of oxide film formed as gate oxide film of transistor
Can also be used. If you do this
A quantity of capacitors can be constructed.

A temperature detecting device for a semiconductor switch element chip of the present invention is a temperature detecting device for detecting a temperature of a chip on which a semiconductor switch element is formed and outputting a signal based on the detected temperature. Based on the temperature detection structure of the semiconductor switch element chip of the present invention in any one of the aforementioned aspects, a current supply unit for supplying a predetermined current to the temperature-voltage characteristic element, and a voltage drop of the temperature-voltage characteristic element. The gist of the present invention is to include a voltage detection unit that detects a voltage.

In the semiconductor switch element chip temperature detection device of the present invention, the semiconductor switch element chip temperature detection structure of the present invention is adapted to prevent an accurate temperature change from the temperature-voltage characteristic element based on the removal of high frequency noise. Since the predetermined voltage characteristic can be taken out, the temperature of the chip can be detected more accurately. Moreover, since a predetermined current is supplied from the current supply unit to the temperature-voltage characteristic element, it is possible to prevent a change in the temperature-voltage characteristic caused by a change in the current.

In such a temperature detecting device for a switch element chip according to the present invention, the voltage detecting section compares the voltage based on the voltage drop of the temperature-voltage characteristic element with a predetermined voltage, and determines which voltage is higher by a binary value. It is also possible to use a comparator that outputs the signal of. Since the temperature-voltage characteristic element has a predetermined voltage characteristic with respect to a change in temperature,
It can be determined that the temperature of the chip has risen above the temperature corresponding to the predetermined voltage in this characteristic.

The semiconductor relay of the present invention is a semiconductor relay which turns off the semiconductor switch element in the on state based on the temperature of the chip on which the semiconductor switch element is formed,
The semiconductor switch element chip temperature detection device of the present invention described above, an ON / OFF signal output section for outputting a signal for controlling ON / OFF of the semiconductor switch element, and the voltage detected by the voltage detection section is equal to or lower than a predetermined voltage. In this case, the on / off signal output section outputs an off signal to the on / off signal output section so that a signal for turning off the semiconductor switching element is output.

In this semiconductor relay of the present invention, the temperature detecting device for the semiconductor switch element chip of the present invention provides a predetermined voltage characteristic to an appropriate temperature change from the temperature-voltage characteristic element based on the removal of high frequency noise. Since the temperature of the chip is taken out and detected more accurately, the semiconductor switch element in the on state can be turned off based on the temperature of the chip without malfunction due to noise.

In such a semiconductor relay of the present invention,
In the temperature detection device, the voltage detection unit may be the comparator, and the OFF signal output unit may be a comparator included in the temperature detection device that outputs one of the binary signals as an OFF signal.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described with reference to examples. FIG. 1 is a configuration diagram showing an outline of a configuration of a semiconductor relay 20 including a temperature detection structure for a semiconductor switch element chip which is an embodiment of the present invention. As shown in the figure, the semiconductor relay 20 of the embodiment includes a semiconductor chip 30 in which an N-channel power MOS (field effect transistor) 32 and a temperature detector 40 are formed, and a power MO.
The drive circuit 50 includes a drive unit 56 that outputs a drive signal to S32 and a temperature processing unit 52 that processes a signal from the temperature detection unit 40 of the semiconductor chip 30.

The drain 33 of the power MOS 32 is connected to the load 48, and the source 35 is grounded. The other end of the load 48 is connected to a load driving power source 49. The gate 34 of the power MOS 32 has the drive circuit 5
0 drive unit 56. Therefore, the power MOS 32 is turned on / off by the drive signal from the drive unit 56 and functions as a drive switch for the load 48.

The temperature detecting section 40 formed on the same chip as the power MOS 32 includes a diode 41 for detecting the temperature of the semiconductor chip 30, a resistor 42 connected in series with the diode 41, and a diode 41 in parallel. And a capacitor 43 connected to the. If the forward bias current is constant, the diode 41 is configured as a general diode that exhibits a highly negative temperature-voltage characteristic with a forward voltage of −1.5 to −2.4 mV / ° C. , Resistor 42 and capacitor 43 are diode 4
It is configured to function as a low-pass filter with respect to the voltage of one terminal.

In the temperature processing unit 52 of the drive circuit 50, one of the input terminals is connected to the resistor 4 of the temperature detection unit 40 via the pad 45.
2 and a reference voltage source 54 independent of temperature which is connected to the other input terminal of the comparator 53. Comparator 53
Compares the reference voltage from the reference voltage source 54 with the forward voltage of the diode 41, and outputs a binary signal determined by its magnitude to the drive unit 56. That is, the comparator 53
Therefore, the output of the driving unit 56 is HI when the forward voltage of the diode 41 is higher than the reference voltage, and is LOW when the forward voltage of the diode 41 is lower than the reference voltage. The reference voltage source 54 is configured so that the forward voltage of the diode 41 becomes the reference voltage when the temperature is higher than the temperature when the load 48 and the power MOS 32 are operating normally and should be determined to be abnormal. Therefore, when the output of the comparator 53 changes from HI to LOW, it means that the semiconductor chip 30 is in an abnormally overheated state. The pad 46 of the semiconductor chip 30 is grounded via the drive circuit 50.

When the signal input from the comparator 53 is HI, the drive unit 56 outputs a drive signal to the gate 34 of the power MOS 32 based on a signal from a circuit (not shown), and the signal input from the comparator 53 is HI.
When it changes from LOW to LOW, the power MOS32
Irrespective of the drive signal output to the gate 34, an off signal for turning off the power MOS 32 is output to the gate 34. Therefore, the semiconductor chip 30
Is overheated and the forward voltage of the diode 41 becomes equal to or lower than the reference voltage, the signal from the comparator 53 becomes LO.
Then, the drive unit 56 turns off the power MOS 32.

Next, the temperature detecting section 40 of the semiconductor chip 30.
Arrangement of the low-pass filters constituting the above will be described.
FIG. 2 is a cross-sectional view illustrating a cross section including the pad 46 of the semiconductor chip 30. As shown, the temperature detection unit 40
The low-pass filter capacitor 43 constituting
The gate oxide film 43b formed on the body 31 is sandwiched between the electrode 43a formed of polysilicon and the N + electrode 43c formed on the body 31 so as to be directly below the pad 46 connected to the pad wire 46a. Has been formed. To form a low-pass filter with a low cutoff frequency, it is necessary to increase the size of the resistor 42 or the capacitor 43, but if either of them is increased, the size of the chip also increases accordingly. On the other hand, power M
A bonding pad for an OS-based element is usually a large one for hitting a thick wire so that it can handle a large current, and no element is arranged below the pad. Therefore, in the embodiment, the capacitor 43 having a large capacitance is used, and the capacitor 43 is formed under the pad where nothing is normally arranged, thereby forming a low-pass filter having a low cutoff frequency and reducing the chip size. I am trying.

The temperature detecting section 40 illustrated in FIG. 1 constitutes one embodiment of the temperature detecting structure of the semiconductor switch element chip of the present invention, and the temperature detecting section 40 and the temperature processing section 52 are the same as those of the present invention. It constitutes an embodiment of a temperature detecting device for a semiconductor switch element chip.

As described above, according to the semiconductor relay 20 of the embodiment, since the temperature detecting section 40 is provided with the low pass filter, the external noise as electromagnetic damage can be removed and the malfunction of the comparator 53 can be prevented. be able to. As a result, the power MOS 32 due to malfunction
Can be prevented from turning off. Moreover, since the capacitor 43 having a large capacitance is usually formed under the bonding pad on which no element is arranged, a low-pass filter having a low cutoff frequency can be configured and the chip can be downsized.

In addition, according to the semiconductor relay 20 of the embodiment, since the capacitor 43 is formed by using the gate oxide film, the characteristics of the gate oxide film of the semiconductor chip 30 (for example, by measuring the characteristics of the capacitor 43). , Film thickness, etc.) can be estimated. As a result, power MOS
It is possible to estimate the cutoff voltage of 32, the response time characteristic, and the like. Further, since the large capacity capacitor 43 is connected to the pads 45 and 46 to which the low-pass filter is connected, the static electricity applied to the pads 45 and 46 is divided, and the energy applied to the internal elements is also attenuated. . As a result, it is possible to improve the electrostatic breakdown resistance of the terminal to which the low-pass filter is connected.

In the semiconductor relay 20 of the embodiment, the semiconductor chip 30 in which the N-channel power MOS 32 is formed
Although the temperature detecting unit 40 is formed on the semiconductor chip, the capacitor 43 can be formed on any semiconductor chip as long as it has a gate oxide film. Therefore, the temperature detecting unit 40 can be formed on a semiconductor chip on which another semiconductor switch element is formed. It may be formed. For example, the semiconductor chip 30B in which the P-channel power MOS 32B illustrated in FIG. 3 is formed.
The structure in which the temperature detection unit 40 is formed, and the N illustrated in FIG.
The temperature detecting unit 40 may be formed in the semiconductor chip 30C in which the channel IGBT 32C is formed.
The temperature detection unit 40 can be formed on a semiconductor chip of a type that does not have a gate oxide film, and can be applied to a semiconductor switch element of this type. In this case, the low-pass filter may be formed by a type of capacitor that does not use an oxide film, or an oxide film may be formed to form a capacitor, and this capacitor may form a low-pass filter.

In the semiconductor relay 20 of the embodiment, the diode 41 is used as an element for detecting the temperature of the semiconductor chip 30, but any element having a temperature-voltage characteristic can be used. For example, the semiconductor chip 30D that uses the sense source detection resistor 41D connected to the sense source illustrated in FIG. 5 as an element for temperature detection may be used.

Further, in the semiconductor relay 20 of the embodiment,
Although the low-pass filter is configured by the resistor 42 and the capacitor 43, the resistor 44 may be inserted between the pad 46 and the low-pass filter as in the semiconductor chip 30E illustrated in FIG. That is, the low-pass filter may have any configuration as long as external noise can be removed.

In the semiconductor relay 20 of the embodiment, the temperature processing section 52 is composed of the comparator 53 which is a comparator, but the semiconductor chip 3 is formed by the forward voltage of the diode 41.
It may be configured by a circuit that calculates a temperature of 0, and outputs a LOW signal to the drive unit 56 when a predetermined temperature is reached.

Although the embodiments of the present invention have been described with reference to the embodiments, the present invention is not limited to the embodiments and various embodiments are possible without departing from the gist of the present invention. Of course, it can be implemented in.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a schematic configuration of a semiconductor relay 20 including a temperature detection structure for a semiconductor switch element chip that is an embodiment of the present invention.

2 is a cross-sectional view illustrating a cross section including a pad 46 of the semiconductor chip 30. FIG.

FIG. 3 is a configuration diagram showing a schematic configuration of a semiconductor chip 30B of a modified example.

FIG. 4 is a configuration diagram showing a schematic configuration of a semiconductor chip 30C of a modified example.

FIG. 5 is a configuration diagram showing a schematic configuration of a semiconductor chip 30D of a modified example.

FIG. 6 is a configuration diagram showing a schematic configuration of a semiconductor chip 30E of a modified example.

[Explanation of symbols]

20 semiconductor relays, 30, 30B, 30C, 30D,
30E semiconductor chip, 31 body, 32 power M
OS, 32B P-channel power MOS, 32C
N-channel IGBT, 33 drain, 34 gate, 35 source, 40 temperature detector, 41 diode, 42 resistor, 43 capacitor, 44 resistor, 4
5, 46 pad, 46a pad wire, 50 drive circuit, 52 temperature processing unit, 53 comparator, 54 reference voltage source, 56 drive unit.

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-64-73756 (JP, A) JP-A-6-260911 (JP, A) JP-A-2-204814 (JP, A) JP-A-7- 115354 (JP, A) JP 10-325761 (JP, A) JP 9-133734 (JP, A) JP 8-236709 (JP, A) JP 8-213441 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H03K 17/14

Claims (11)

(57) [Claims] 1. A chip on which a semiconductor switch element is formed.
Temperature and generates voltage based on the detected temperature
A temperature sensing structure, the temperature detecting structure, the semiconductor switching element is formed on the formed chip, a temperature voltage characteristic element having a predetermined voltage characteristic with respect to changes in temperature, the temperature-voltage characteristic The temperature-voltage characteristic element connected to the element
And a low pass filter for removing high frequency components of the voltage signal generated in the low pass filter in series with the temperature-voltage characteristic element
Connected in parallel with the resistance connected to the temperature-voltage characteristic element
It is a filter that is composed of
A temperature detection structure characterized in that 2. The temperature detecting structure according to claim 1.
Then, the chip detects the voltage generated by the temperature detection structure.
Check the bonding pad for electrical connection to the outside.
The top surface of the bonding pad, the capacitor is formed under the bonding pad.
Temperature detection structure characterized by being 3. The temperature detecting structure according to claim 1 or 2.
A is the temperature voltage characteristic element, characterized in that a diode
And temperature detection structure. 4. The method according to any one of claims 1 to 3.
The temperature detecting structure, wherein the temperature-voltage characteristic element is a resistor . 5. The method according to any one of claims 1 to 4.
In the temperature detection structure, the semiconductor switch element is a field effect transistor or
Is a bipolar transistor . Temperature detection structure. 6. The method according to any one of claims 1 to 5.
In the temperature detection structure, the capacitor has a semiconductor oxide film made of polysilicon.
On the chip substrate and the first electrode formed by
Structure sandwiched by a second electrode formed by pinging
A temperature detection structure characterized by: 7. The temperature detecting structure according to claim 6,
The semiconductor switch element is a field effect transistor.
The semiconductor oxide film is a gate of the field effect transistor.
Use part of the oxide film formed as the oxide film
Features a temperature detection structure. 8. A temperature detecting device for detecting a temperature of a chip having a semiconductor switch element formed thereon, and outputting a signal based on the detected temperature, wherein the temperature detecting device is any one of claims 1 to 7. temperature sensing apparatus comprising a temperature detection structure, a current supply unit for supplying a predetermined current to the temperature voltage characteristic element, a voltage detection unit that detects a voltage based on the voltage drop of the temperature-voltage characteristic element according to. 9. The voltage detection unit is a comparator that compares a voltage based on a voltage drop of the temperature-voltage characteristic element with a predetermined voltage and outputs which voltage is higher as a binary signal. 8. The temperature detection device according to 8. 10. A semiconductor relay for turning off the semiconductor switch element in an on state based on the temperature of a chip on which the semiconductor switch element is formed, the temperature detecting device according to claim 8 or 9, and the semiconductor switch element. An on / off signal output section that outputs a signal that controls the on / off of the semiconductor device, and a signal that turns off the semiconductor switch element is output from the on / off signal output section when the voltage detected by the voltage detection section becomes equal to or lower than a predetermined voltage. And an off signal output part for outputting an off signal to the on / off signal output part. 11. The semiconductor device according to claim 10, wherein the off-signal output unit is a comparator included in the temperature detection device that outputs one of the binary signals as an off signal. relay.