JP6315190B2 - Driving device for vehicle ignition device - Google Patents

Description

The present invention relates to a drive device for a vehicle ignition device having improved surge resistance.

Patent Document 1 discloses a driving device for a conventional vehicle ignition device that includes a control circuit, a switching element, and a power supply protection element. The control circuit performs open / close drive control of the switching element in accordance with an ignition signal transmitted from an electronic control device provided outside, in accordance with the operating state of the internal combustion engine. The power supply protection element is provided between the high-voltage side wiring and the ground side wiring, and includes at least a semiconductor element having a voltage limiting function such as a Zener diode or an avalanche diode. The power protection element limits the input voltage when the battery voltage applied from the power supply external to the drive device is input to the control circuit, or removes the surge voltage generated when the switching element is opened or closed. Protect the control circuit.

Further, Patent Document 1 describes that the control circuit, the switching element, and the power supply protection element may be formed as a single semiconductor integrated circuit in order to reduce the size of the driving device.

JP 2012-154227 A

However, Patent Document 1 does not disclose a specific method for forming a control circuit, a switching element, and a power protection element in a semiconductor integrated circuit. The present invention provides a drive device for a vehicle ignition device that includes a power protection element and has improved surge resistance.

According to one aspect of the present invention, a drive device for a vehicle ignition device includes a switching element and a semiconductor integrated circuit that drives the switching element, and the semiconductor integrated circuit protects the drive circuit and the drive circuit from surges. A power source protection element, a drive circuit, and an element isolation region that divides the power source protection element, wherein the power source protection element is provided on a semiconductor substrate including first and second main surfaces facing each other. An anode region of one conductivity type, a cathode region of a second conductivity type provided so as to be in contact with the anode region, and provided so as to be electrically connected to the anode region and exposed to the first main surface The first conductivity type anode contact region and the second conductivity type cathode provided so as to be electrically connected to the cathode region and exposed to the first main surface Comprising a contact region, the impurity concentration of the anode region is equal to the impurity concentration of the cathode region, the impurity concentration of the anode contact region state, and are more than 100 times the impurity concentration of the anode region, said isolation The region has a first conductivity type, and on the first main surface opposite to the power protection element across the element isolation region, the element isolation region, the first conductivity type first semiconductor region, and Having a second conductivity type region opposite to the first conductivity type between the semiconductor region exposed to the first main surface of the element isolation region and the first semiconductor region, the distance between the anode region and the anode region. A parasitic PNP transistor current amplification factor generated in the region, the cathode region, and the second semiconductor region exposed on the second main surface of the semiconductor substrate; the cathode region; the second semiconductor region; of The product of the current amplification factor of the parasitic NPN transistor produced by the third semiconductor region of the second conductivity type which is connected to the conductor region is characterized to Rukoto to be 1 or less.

In the present invention, the impurity concentration in the anode region is defined to be equal to the impurity concentration in the cathode region if it is in the range of 0.5 to 2.0 times the impurity concentration in the cathode region.

ADVANTAGE OF THE INVENTION According to this invention, the drive device of the ignition device for vehicles which has a power supply protection element and has the improved surge tolerance can be provided.

1 is a circuit diagram showing a configuration of a drive device for a vehicle ignition device according to a first embodiment of the present invention. 1 is a cross-sectional view showing a configuration of a semiconductor integrated circuit according to a first embodiment of the present invention. 1 is a cross-sectional view showing a configuration of a semiconductor integrated circuit according to a first embodiment of the present invention. It is sectional drawing which shows the structure of the semiconductor integrated circuit which concerns on the 2nd Embodiment of this invention.

Next, an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic. Further, the embodiments described below exemplify apparatuses and methods for embodying the technical idea of the present invention, and the embodiments of the present invention have the following structure and arrangement of components. It is not something specific. The embodiment of the present invention can be variously modified within the scope of the claims.

FIG. 1 is a circuit diagram showing a configuration of a drive device for a vehicle ignition device according to a first embodiment of the present invention. The vehicle ignition device 100 according to the present embodiment includes a DC power supply VB, a transformer TR, a drive device 10, and a control unit MCU. The drive device 10 according to the present embodiment includes a switching element SW and a semiconductor integrated circuit IC. The DC power supply VB, the primary winding of the transformer TR, and the switching element SW are connected in series. The semiconductor integrated circuit IC is connected to the DC power supply VB, the control unit MCU, and the switching element SW, obtains drive power from the DC power supply VB, and drives the switching element SW based on a control signal from the control unit MCU.

The semiconductor integrated circuit IC includes a drive circuit DRV, a power supply protection element ZD1, and an input protection element ZD2 on a single semiconductor substrate. Drive circuit DRV is connected to DC power supply VB, control unit MCU, and switching element SW. The power supply protection element ZD1 is formed of a Zener diode, is connected to the DC power supply VB and the drive circuit DRV, and protects the drive circuit DRV from a surge. The input protection element ZD2 includes a Zener diode, is connected to the control unit MCU and the drive circuit DRV, and protects the drive circuit DRV from a surge.

FIG. 2 is a cross-sectional view showing the configuration of the semiconductor integrated circuit according to the first embodiment of the present invention. The power supply protection element ZD1 includes an anode region 17, a cathode region 13, an anode contact region 18, and a cathode contact region 20 provided on the semiconductor substrate SUB including the first and second main surfaces S1 and S2 facing each other. . The impurity concentration of the anode region 17 is equal to the impurity concentration of the cathode region 13, and the impurity concentration of the anode contact region 18 is 100 times or more the impurity concentration of the anode region.

The first semiconductor layer 11 has a P-type conductivity, is exposed on the second main surface S2 of the semiconductor substrate SUB, and is grounded. The second semiconductor layer 12 has an N-type conductivity, is in contact with the first semiconductor layer 11, and is exposed on the first main surface S1 of the semiconductor substrate SUB. The first semiconductor region (cathode region) 13 has an N-type conductivity type and is in contact with the first semiconductor layer 11 and the second semiconductor layer 12. The second semiconductor region 14 has an N-type conductivity type and is formed inside the first semiconductor region 13. The third semiconductor region 15 has a P-type conductivity and is in contact with the first semiconductor layer 11 and the second semiconductor layer 12. The fourth semiconductor region 16 has a P-type conductivity and is in contact with the first semiconductor layer 11 and the second semiconductor layer 12. The fifth semiconductor region (anode region) 17 has a P-type conductivity type, is in contact with the first semiconductor region 13, and is exposed on the first main surface S1 of the semiconductor substrate SUB. The sixth semiconductor region (anode contact region) 18 has P-type conductivity, is electrically connected to the fifth semiconductor region 17, and is exposed on the first main surface S1 of the semiconductor substrate SUB. The seventh semiconductor region 19 has an N-type conductivity, is in contact with the second semiconductor region 14, and is exposed on the first main surface S1 of the semiconductor substrate SUB. The eighth semiconductor region (cathode contact region) 20 is electrically connected to the first semiconductor region 13 via the second and seventh semiconductor regions 14 and 19, and the first main surface S1 of the semiconductor substrate SUB. Exposed to. The ninth semiconductor region 21 has a P-type conductivity, is in contact with the third semiconductor region 15, and is exposed on the first main surface S1 of the semiconductor substrate SUB. The tenth semiconductor region 22 has a P-type conductivity, is electrically connected to the third semiconductor region 15 via the ninth semiconductor region 21, and is formed on the first main surface S1 of the semiconductor substrate SUB. Exposed. The eleventh semiconductor region 23 has P-type conductivity, is in contact with the fourth semiconductor region 16, and is exposed to the first main surface S1 of the semiconductor substrate SUB. The twelfth semiconductor region 24 has P-type conductivity, is electrically connected to the fourth semiconductor region 16 through the eleventh semiconductor region 23, and is formed on the first main surface S1 of the semiconductor substrate SUB. Exposed. The thirteenth semiconductor region 25 has an N-type conductivity, is in contact with the second semiconductor layer 12, and is exposed on the first main surface S1 of the semiconductor substrate SUB. The first to twelfth semiconductor regions are impurity diffusion regions formed by introducing P-type or N-type impurities into the semiconductor substrate SUB. The insulating film 26 partially covers the first main surface S1 of the semiconductor substrate SUB.

The impurity concentration of the first semiconductor region 13 is 1 × 10 ¹⁷ to 1 × 10 ¹⁸ cm ⁻³ . The impurity concentration of the fifth semiconductor region 17 is 1 × 10 ¹⁷ to 1 × 10 ¹⁸ cm ⁻³ , and is set to 0.5 to 2.0 times the impurity concentration of the first semiconductor region 13. The impurity concentration of the second semiconductor region 14 is 1 to 5 × 10 ¹⁹ cm ⁻³ . The impurity concentration of the third and fourth semiconductor regions 15 and 16 is 5 × 10 ¹⁷ cm ^{−3 to} 5 × 10 ¹⁸ cm ⁻³ . The impurity concentration of the sixth semiconductor region 18 is 5 × 10 ¹⁸ to 1 × 10 ²⁰ cm ⁻³ . The impurity concentration of the sixth semiconductor region 18 is set to 100 times or more the impurity concentration of the fifth semiconductor region 17. The impurity concentration of the seventh semiconductor region 19 is 1 to 5 × 10 ¹⁹ cm ⁻³ . The impurity concentration of the eighth impurity region 20 is 2 to 8 × 10 ²⁰ cm ⁻³ . The impurity concentration of the ninth and eleventh semiconductor regions 21 and 23 is 1 × 10 ¹⁸ to 1 × 10 ¹⁹ cm ⁻³ . The impurity concentration of the tenth and twelfth semiconductor regions 22 and 24 is 5 × 10 ¹⁸ to 1 × 10 ²⁰ cm ⁻³ , which is equal to the impurity concentration of the sixth semiconductor region 18. The impurity concentration of the thirteenth semiconductor region 25 is 2 to 8 × 10 ²⁰ cm ⁻³ , which is equal to the impurity concentration of the eighth impurity region 20.

The semiconductor region including the first semiconductor region 13 and the fifth semiconductor region 17 constitutes a lateral power supply protection element ZD1 having a main current path parallel to the main surface of the semiconductor substrate SUB. The ninth and tenth semiconductor regions 21 and 22 are regions that define the outer peripheral edge of the power supply protection element ZD1, and constitute element isolation regions that electrically isolate other circuit elements. In addition, the semiconductor integrated circuit IC includes a parasitic element as indicated by a broken line in a region where the power protection element ZD1 is formed. The parasitic element includes a PNP transistor TR1, an NPN transistor TR2, and first and second resistors R1 and R2, and constitutes a thyristor as a whole. The power supply protection element ZD1 is required to absorb various surge voltages as the drive device 10 of the vehicle ignition device. Therefore, in order to provide the power supply protection element ZD1 in the semiconductor integrated circuit IC, the latch-up of the thyristor must be suppressed. In the semiconductor integrated circuit IC according to this embodiment, the distance D between the ninth semiconductor region 21 and the twelfth semiconductor region 24 is set so that the product of hfe (current amplification factor) of the PNP transistor TR1 and hfe of the NPN transistor TR2 is 1. It was set as the distance which becomes below. Therefore, the operation of the parasitic thyristor due to the surge voltage is suppressed, and the destruction of the power supply protection element ZD1 is prevented. Therefore, the semiconductor integrated circuit IC according to the present embodiment provides a drive device for a vehicle ignition device that includes a power protection element and has improved surge resistance.

The various surge voltages are high-frequency or low-frequency surge voltages such as air ESD, contact ESD, field decay, and load dump. Moreover, the surge voltage tolerance of positive direction and negative direction can be improved by connecting the protection element which has the structure similar to power supply protection element ZD1 in anti-series.

FIG. 3 is a cross-sectional view showing the configuration of the semiconductor integrated circuit according to the first embodiment of the present invention. The input protection element ZD2 is provided on the semiconductor substrate SUB similarly to the power supply protection element ZD1. The input protection element ZD2 includes an anode region 28, a cathode region 27, an anode contact region 30, and a cathode contact region 32.

The fourteenth semiconductor region (cathode region) 27 has an N-type conductivity type and is in contact with the first semiconductor layer 11 and the second semiconductor layer 12. The fifteenth semiconductor region (anode region) 28 has a P-type conductivity and is in contact with the fourteenth semiconductor region 27. The sixteenth semiconductor region 29 has a P-type conductivity, is in contact with the fifteenth semiconductor region 28, and is exposed on the first main surface S1 of the semiconductor substrate SUB. The seventeenth semiconductor region 30 (anode contact region) has a P-type conductivity, is in contact with the sixteenth semiconductor region 29, and is exposed on the first main surface S1 of the semiconductor substrate SUB. The eighteenth semiconductor region 31 has an N-type conductivity, is in contact with the fourteenth semiconductor region 27, and is exposed on the first main surface S1 of the semiconductor substrate SUB. The nineteenth semiconductor region 32 (cathode contact region) has an N-type conductivity type, is in contact with the eighteenth semiconductor region 31, and is exposed on the first main surface S1 of the semiconductor substrate SUB.

The impurity concentration of the fourteenth semiconductor region 27 is equal to that of the second semiconductor region 14 and is 1 to 5 × 10 ¹⁹ cm ⁻³ . The impurity concentration of the fifteenth semiconductor region 28 is lower than that of the third and fourth semiconductor regions 15 and 16, and is 1 × 10 ¹⁷ cm ^{−3 to} 5 × 10 ¹⁸ cm ⁻³ . The impurity concentration of the sixteenth semiconductor region 29 is 1 × 10 ^{18 to} 5 × 10 ¹⁹ cm ⁻³ . The impurity concentration of the seventeenth semiconductor region 30 is equal to that of the sixth semiconductor region 18 and is 5 × 10 ¹⁸ to 1 × 10 ²⁰ cm ⁻³ . The impurity concentration of the eighteenth semiconductor region 31 is equal to that of the seventh semiconductor region 19 and is 1 to 5 × 10 ¹⁹ cm ⁻³ . The impurity concentration of the nineteenth semiconductor region 32 is equal to that of the eighth impurity region 20 and is 2 to 8 × 10 ²⁰ cm ⁻³ .

Since the semiconductor integrated circuit IC according to this embodiment includes the input protection element ZD2 configured as described above in addition to the power supply protection element ZD1, a drive device for a vehicle ignition device having improved surge resistance is provided. The

FIG. 4 is a sectional view showing a configuration of a semiconductor integrated circuit according to the second embodiment of the present invention. The semiconductor integrated circuit according to the present embodiment is different from the semiconductor integrated circuit according to the first embodiment in that it includes a twentieth semiconductor region (anode intermediate region) 33. The twentieth semiconductor region 33 has a P-type conductivity, is interposed between the fifth semiconductor region 17 and the sixth semiconductor region 18, and is exposed to the first main surface S1 of the semiconductor substrate SUB. The impurity concentration of the twentieth semiconductor region 33 is 1 × 10 ¹⁶ to 1 × 10 ¹⁷ cm ⁻³ , and is set to about 0.1 times the impurity concentration of the fifth semiconductor region 17. By providing the twentieth semiconductor region 33, the impedance of the power supply protection element ZD1 becomes low. Therefore, the semiconductor integrated circuit IC according to the present embodiment provides a drive device for a vehicle ignition device having further improved surge resistance.

As mentioned above, although this invention was described by embodiment, it should not be understood that the description and drawing which form a part of this indication limit this invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art. That is, it goes without saying that the present invention includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description. For example, the semiconductor integrated circuit IC may include a switching element SW. Further, the driving device 10 may include a control unit MCU.

DESCRIPTION OF SYMBOLS 10 Drive apparatus 100 Vehicle ignition device SW Switching element MCU Control part IC Semiconductor integrated circuit DRV Drive circuit ZD1 Power supply protection element ZD2 Input protection element 13 1st semiconductor area | region (cathode area | region)
17 Fifth semiconductor region (anode region)
18 Sixth semiconductor region (anode contact region)
20 Eighth semiconductor region (cathode contact region)
33 20th semiconductor region (anode intermediate region)

Claims (1)

A switching element and a semiconductor integrated circuit for driving the switching element,
The semiconductor integrated circuit includes a drive circuit, a power protection element that protects the drive circuit from a surge , and an element isolation region that divides the drive circuit and the power protection element .
The power protection element includes a first conductivity type anode region provided on a semiconductor substrate including first and second main surfaces facing each other;
A cathode region of a second conductivity type provided in contact with the anode region;
An anode contact region of the first conductivity type provided so as to be electrically connected to the anode region and exposed to the first main surface;
A cathode contact region of the second conductivity type provided so as to be electrically connected to the cathode region and exposed to the first main surface,
The impurity concentration of the anode region is equal to the impurity concentration of the cathode region, the impurity concentration of the anode contact region state, and are more than 100 times the impurity concentration of the anode region,
The element isolation region has a first conductivity type,
The first main surface opposite to the power protection element across the element isolation region is opposite to the first conductivity type between the element isolation region and the first conductivity type first semiconductor region. Having a second conductivity type region;
The distance between the semiconductor region exposed on the first main surface of the element isolation region and the first semiconductor region is
A current amplification factor of a parasitic PNP transistor generated in the anode region, the cathode region, and the second semiconductor region exposed on the second main surface of the semiconductor substrate; the cathode region; the second semiconductor region; first second conductivity type which is connected to the semiconductor region the third semiconductor region and the vehicle ignition device for the product of the current amplification factor of the parasitic NPN transistor produced is characterized to Rukoto to be 1 or less in the Drive device.

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