JP5063572B2 - In-vehicle electronic control unit - Google Patents

Description

  The present invention relates to an in-vehicle electronic control device equipped with a microprocessor and an input / output circuit, and particularly in a multilayer electronic board of the in-vehicle electronic control device. The present invention relates to an on-vehicle electronic control device having an improved circuit.

Various input sensor groups and various electric load groups connected to the in-vehicle electronic control device via the wire harness are dispersedly installed in various places on the vehicle, and the wire diameter of the wire harness is thin for cost reduction. Since the whole is tightly bound, it is in an environment where a voltage drop occurs and it is susceptible to inductive noise.
Although the negative terminal potential of each part of the in-vehicle electronic control device, various input sensor groups, and various electric load groups is ideally the same as the reference vehicle body potential of the part where the negative terminal of the in-vehicle battery is connected. In reality, there are various potential fluctuations.
On the other hand, the ground circuit in the in-vehicle electronic board is connected to the negative terminal of the in-vehicle battery, and the stabilized power supply circuit for driving the microprocessor has a non-insulated and inexpensive circuit configuration. In addition, the ground circuit of the weak electric control system is directly connected to each other.

There are various methods for configuring a ground circuit in an electronic substrate based on various ideas. For example, according to Patent Document 1 below, the printed circuit board 56 is provided with first and second ground patterns 57 and 58, and the first ground pattern 57 is connected to the vehicle-mounted battery 72 via the metal case 60 and the vehicle body 62. Is connected to the negative terminal. The second ground pattern 58 is directly connected to the small current ground line 52 and is connected to the negative terminal of the in-vehicle battery 72.
Further, a large current ground line 55 connected to the large current output control transistor 53 is provided, and the large current ground line 55 is connected to the negative terminal of the in-vehicle battery 72 by a wiring independent of the small current ground line 52. .

Further, the signal input lines 47 to 49 and the small current output line 51 are connected to the second ground pattern 58 by EMI capacitors 67, 68, 69 and 70, and the power line 43, the large current ground line 55 and the large current output. The line 54 is connected to the first ground pattern 57 by EMI capacitors 64, 65 and 66, and the EMI capacitor 63 is also connected between the first and second ground patterns 57 and 58.
With such a configuration, it is possible to prevent fluctuations in the ground potential of the signal input / output system due to driving of the solenoid or the like without impairing countermeasures against radio wave interference against high frequency noise from the outside.

Japanese Patent Application Laid-Open No. 09-312488 (FIG. 2, summary)

The ground structure according to Patent Document 1 includes two types of ground patterns that are not directly connected to each other in the electronic board, and as a connection to the negative terminal of the in-vehicle battery, in addition to the vehicle body connection portion, a large current ground line and a small ground pattern are provided. Two wire harnesses for connecting a current ground line are provided. Accordingly, there is a drawback that potential fluctuation is likely to occur between the large current ground line and the small current ground line in the electronic substrate, and an extra external wiring is required.
In particular, the power supply line and ground line for the in-vehicle battery use a plurality of connection pins in parallel in order to increase the contact reliability of the connector. Therefore, providing a separate ground line has the problem of increasing the size of the connector. is there.

The first object of the present invention is to reduce the number of external wirings for power supply connecting between the ground terminal of the in-vehicle electronic board and the negative terminal of the in-vehicle battery, and the board for the weak electric control system even if a large current flows in the electronic board It is providing the vehicle-mounted electronic control apparatus which can suppress the fluctuation | variation of an internal ground potential.
A second object of the present invention is to provide an in-vehicle electronic control device capable of avoiding crossing of input / output wirings connected to a large number of external connection terminal groups.
The third object of the present invention is to suppress control malfunctions due to high frequency induction noise, and to perform stable control operations even when fluctuations in the negative terminal potential of the in-vehicle electronic control device, various sensor groups, and various in-vehicle electric load groups occur. It is to provide an in-vehicle electronic control device that can be used.

The in-vehicle electronic control device according to the present invention is a variety of in-vehicle electric devices in response to the operating state of a constant-voltage power supply circuit element that is supplied with power from an in-vehicle battery and generates a predetermined stabilization voltage, and a switch sensor and an analog sensor. An output element module for driving a large current load, which is an open / close element for driving and controlling a load group, a control circuit element including a microprocessor and driven by a stabilizing voltage, and an input / output interface circuit are mounted. An in-vehicle electronic control device having a multilayer electronic substrate to which a connector for external connection connected to an in-vehicle electrical load group and an in-vehicle sensor group is attached and detached ,
The multilayer electronic board has at least three insulating base layers and four wiring pattern surfaces and has a rectangular shape, at least one of which is a surface signal layer and back signal layer serving as a component mounting surface, and a ground serving as an intermediate layer The planar ground pattern provided on the ground layer that constitutes the layer and the power supply layer and is located in the first specific intermediate layer of the multilayer electronic substrate is divided and separated into the power ground region and the signal ground region by the partitioning slit. In addition, the power ground area and the signal ground area are connected to each other in a specific connection area without a partition slit ,
The power ground area is provided on the outer peripheral side of the multilayer electronic board on which the connector for external connection is mounted and the adjacent side orthogonal to the outer peripheral side, and the power ground area is connected to the negative terminal of the vehicle battery via the external connection connector. At the same time, the power ground area is equipped with the input circuit section of the output element module and the constant voltage power supply circuit element, and the signal ground area is equipped with an input / output interface circuit including an input interface circuit for the control circuit element and the analog sensor. And
The planar power supply pattern provided in the power supply layer located in the second specific intermediate layer of the multilayer electronic board is divided into input power supply pattern and output power supply pattern areas by the dividing slits. Connected to the positive terminal, the output power supply pattern is connected to the positive terminal output circuit of the constant voltage power supply circuit element, the region of the output power supply pattern is divided into a plurality of output power supply patterns corresponding to different output voltages, The output element module includes a monitor circuit, and the monitor circuit includes a latch circuit that detects and stores the presence or absence of disconnection or short circuit of the output transistor that constitutes the output element module, or an overheat abnormality.
A bypass capacitor is disposed in the vicinity of the output element module mounted in the power ground area, and the bypass capacitor is connected between the negative terminal of the output element module and the negative terminal of the control circuit element or the input / output interface circuit. The signal ground area and the negative terminal of the analog sensor are connected by signal ground wiring to at least a part of the analog sensors in the in-vehicle sensor group, and the specific connection area between the power ground area and the signal ground area Is located at the output circuit portion of the constant voltage power supply circuit element, and the connection width in the specific connection region is shorter than the length of the partitioning slit.

In the vehicle-mounted electronic control device according to the present invention, the planar ground pattern located on the first specific layer of the multilayer electronic substrate is separated into a power ground region and a signal ground region, and is specified at the output portion of the constant voltage power circuit element. While being connected to each other in the connection region, a signal ground line is connected to a part of the analog sensor.
Therefore, some of the analog sensors that require high accuracy are configured so that their negative terminal potential levels are the same by the signal ground wiring, thereby eliminating the influence of potential fluctuations due to intermittent load currents. In addition, the ground potential in the signal ground area is unlikely to fluctuate in response to fluctuations in the load current due to the switching operation of the output element module, which is a load drive switching element mounted in the power ground area, and the microprocessor mounted in the signal ground area In addition, there is an effect of suppressing malfunctions related to transmission / reception of monitoring / control signals between the output element modules provided in the power ground region.

Embodiment 1 FIG.
Hereinafter, an in-vehicle electronic control device according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 is an overall circuit diagram of an in-vehicle electronic control device according to the present invention, FIG. 2 is a partial detailed view of an input / output interface circuit shown in FIG. 1, FIG. 3 is a housing assembly structure diagram of the in-vehicle electronic control device, and FIG. FIG. 5 is a configuration diagram of a wiring pattern surface of the multilayer electronic substrate, and FIG. 6 is a sectional view of the multilayer electronic substrate.

First, FIG. 1, which is an overall circuit diagram of an in-vehicle electronic control device using the multilayer electronic substrate of the present invention, will be described.
In FIG. 1, an in-vehicle electronic control device 100 is an engine control device, for example, an in-vehicle battery 101 supplies power to the in-vehicle electronic control device 100 via an output contact 102a of a power relay, and an excitation coil 102b of the power relay is controlled by a power switch 103. The vehicle-mounted electronic control device 100 is energized by being closed and controlled to be delayed by the power switch 103 being opened.
The analog sensor 104, which is one of the in-vehicle sensors, includes, for example, an accelerator position sensor that detects the degree of depression of the accelerator pedal, a throttle position sensor that detects the throttle valve opening, an airflow sensor that measures the intake air amount of the engine, an exhaust gas sensor, It is an analog sensor that detects the engine environment and operating state, such as a coolant temperature sensor. The switch sensor 105, which is another member of the in-vehicle sensor group, is an open / close that detects the driver's operation command and the operating state of each part, such as an engine rotation sensor, a crank angle sensor, a vehicle speed sensor, and a shift lever position detection sensor of the transmission. It is an operation sensor.

The small current electric load 106 which is one of the in-vehicle electric load groups is, for example, the excitation coil 102b of the power relay described above, or an ignition coil to which a power transistor is externally attached. The large current electric load 107, which is another member of the in-vehicle electric load group, is, for example, a throttle valve opening control motor or a fuel injection electromagnetic valve, and the large current electric load is an in-vehicle electronic control device. The power supply is driven through output element modules 32b and 32c, which are power transistors provided in 100.
The signal ground wiring 108a connects a part of the negative terminals of the analog sensor 104 and the signal ground in the in-vehicle electronic control device 100, and a plurality of signal ground wirings 108a are provided depending on the installation location of each analog sensor. Is used. A part of the analog sensors 104 is supplied with a stabilization control voltage from the in-vehicle electronic control device 100 through the signal power supply line 108b.
The vehicle body grounding part 109a is a reference grounding point to which the negative terminal of the vehicle-mounted battery 101 is connected. The vehicle-mounted electronic control device 100 is connected to the vehicle body grounding part 109a by a ground wiring 109b, which will be described later. As described above, the electronic substrate in the in-vehicle electronic control device 100 has a ground pattern of a power ground region 421 and a signal ground region 423, and each ground region is combined on the electronic substrate and integrated with each other via a plurality of connection terminals. And connected to the vehicle body grounding part 109a.

As an internal configuration of the in-vehicle electronic control device 100, the constant voltage power supply device 110 includes a constant voltage power supply circuit element 31a (see FIG. 4) that is a plurality of power transistors and a constant voltage control circuit unit (not shown), and outputs the power relay. The first to fifth output voltages are generated by the main power supply voltage Vb fed through the contact 102a and the sub power supply voltage Vbb fed directly from the in-vehicle battery 101.
The first output voltage Vcc is stepped down from the main power supply voltage Vb, generates a stabilized voltage of, for example, DC5V, and serves as a main output power supply that supplies power to each of the interface circuits 116, 125, and 126 described later.
The second output voltage Vad is stepped down from the main power supply voltage Vb to generate a high-accuracy stabilized voltage of, for example, DC 5 V, and serves as a small-capacity power supply that supplies power to an analog interface circuit 114 and an AD converter 124 described later. .
The third output voltage Vcp is stepped down from the main power supply voltage Vb to generate a stabilized voltage of, for example, DC 3.3V, and a power supply for an arithmetic processing system that supplies power to a microprocessor 121 and various memories 122, 123a, 123b described later. It has become.

The fourth output voltage Vup is stepped down from the sub power supply voltage Vbb to generate a stabilized voltage of, for example, DC 2.8V, and serves as a small capacity power supply that supplies power to the backup memory 123b, which is a partial area of the RAM memory.
The fifth output voltage Vscp is stepped down from the sub power supply voltage Vbb to generate a stabilized power voltage of, for example, DC 5 V, and serves as a small capacity power source for supplying power to the auxiliary microprocessor 131 serving as a soak timer.
The soak timer is for periodically starting the microprocessor 121 for a very short time and monitoring and storing the state of the vehicle when the power switch 103 is open.
The short circuit protection circuit 111 configured by a buffer amplifier is provided in a path for supplying the second output voltage Vad to the analog sensor 104, and the constant voltage power supply device 110 is not burned even if a short circuit abnormality occurs in the signal power supply wiring 108b. This is a protection circuit.
The diode 112 is provided in a power supply circuit for holding the storage operation of the backup memory 123b by the fourth output voltage Vup when the power switch 103 is open. The diode 113 is closed when the power switch 103 is closed. Is provided in the power supply circuit for holding the storage operation of the backup memory 123b by the third output voltage Vcp.

The contents of the input / output interface circuit 34 and the output element module 117 constituted by the analog interface circuit 114, the input interface circuit 115, and the output interface circuit 116 are as described later with reference to FIG. The first and second output element modules 32b and 32c are included, and each output element module 117 is conduction-controlled by a drive command from the output interface 116 or the primary output interface circuit 126 as shown in FIG. A power transistor and a monitor circuit that monitors the operating state of the power transistor and serially transmits it to the microprocessor 121 are provided.
The control circuit element 120 includes an integrated circuit element 127, an auxiliary microprocessor 131 serially connected to a microprocessor 121 described later, and a nonvolatile data memory 132.
The integrated circuit element 127 includes, for example, a 32-bit microprocessor 121, a program memory 122 that is, for example, a nonvolatile flash memory that cooperates with the microprocessor 121, a RAM memory 123a for arithmetic processing, and a partial area of the RAM memory. A backup memory 123b that is continuously supplied with power even when the power switch 103 is open is provided.

The multi-channel AD converter 124 provided in the integrated circuit element 127 converts the analog signal input from the analog interface circuit 114 into a digital signal and supplies it to the microprocessor 121.
Further, the secondary input interface circuit 125 provided in the integrated circuit element 127 converts the voltage level of the open / close logic signal input from the interface circuit 115 from the DC5V system to the DC3.3V system and supplies it to the microprocessor 121. Is for.
Similarly, a primary output interface circuit 126 provided in the integrated circuit element 127 converts a DC 3.3V logic signal output from the microprocessor 121 into a DC 5V system and supplies it to the output interface circuit 116. These input / output interface circuits 125 and 126, the multi-channel AD converter 124, various memories 122, 123 a and 123 b, and the microprocessor 121 are connected to each other by a data bus 128.

Next, FIG. 2 which is a partial detailed view of the input / output interface circuit shown in FIG. 1 will be described.
In FIG. 2, a potentiometer 104 a which is an example of the analog sensor 104 is connected to the on-vehicle electronic control device 100 by a signal power supply wiring 108 b, a signal ground wiring 108 a, and a variable voltage signal terminal wiring 108 c, and is connected to the analog input interface circuit 114. The input analog signal voltage is supplied to the multi-channel AD converter 124 via a noise filter 143 constituted by a series resistor 141 and a smoothing capacitor 142, and a positive / negative clip diode 144 connected to a power supply circuit and a ground circuit. 145 limits the excessive noise voltage.
The analog system input interface circuit 114 includes a noise filter 143 and positive and negative clip diodes 144 and 145.

One end of an opening / closing element 105a, which is an example of the switch sensor 105, is grounded to a nearby vehicle body, and the other end is connected to an input interface circuit 115 to which a main power supply voltage Vb is applied via a pull-up resistor 151.
The noise filter 152 includes a series resistor 153 and a smoothing capacitor 154, and supplies an opening / closing signal from the opening / closing element 105a to the hysteresis circuit 155. The hysteresis circuit 155 includes a comparison circuit 156 that compares the output voltage of the noise filter 152 and the comparison reference voltage 157 and supplies the comparison output to the secondary input interface circuit 125, and the output terminal of the comparison circuit 156 is positive. It is connected to the positive input terminal via the feedback resistor 158.
Therefore, in the process of increasing the output voltage of the noise filter 152, when the output voltage exceeds the comparison reference voltage 157, the output logic of the comparison circuit 156 becomes “H”, and once the output logic becomes “H”, positive feedback Since the positive input voltage is added by the resistor 158, the output logic of the comparison circuit 156 continues to be “H” until the output voltage of the noise filter 152 decreases to an output voltage lower than the comparison reference voltage 157. It has become.

As a result, for example, the input voltage at which the output logic of the comparison circuit 156 rises and reverses from “L” to “H” is DC 3.5 V, and conversely, the input voltage that falls and reverses from “H” to “L” becomes DC 1.5 V. If the constants are set in this way, a hysteresis band of DC2V is obtained. For example, when the switching element 105a is closed, the vehicle body ground potential and the ground potential of the input interface circuit 115 fluctuate. If the width is less than 2V, the output logic of the comparison circuit 156 does not reciprocate alternately.
In the case of a positive common type sensor in which one end of the switching element 105a is connected to a positive power supply line, a pull-down resistor is used instead of the pull-up resistor 151. The pull-down resistor is for determining the input signal potential when the switching element 105a is open.

As an example of the small current on-vehicle electric load 106, the specific electric load 106a is, for example, an ignition coil, the specific electric load 106a includes a load driving transistor 106b, and a hysteresis circuit 106c is provided as an input circuit of the load driving transistor 106b. Is provided.
Accordingly, the load driving transistor 106b is turned on when the drive command signal is, for example, 3.5V or more, and the load drive transistor 106b is turned off when the drive command signal is, for example, 1.5V or less.
The output interface circuit 116 supplies a drive command signal to the input terminal of the hysteresis circuit 106c through the short-circuit protection series resistor 162 from the output transistor 161 fed from the first output voltage Vcc.
The pull-down resistor 163 is for stabilizing the command signal when the output transistor 161 is open to the ground potential, and the drive resistor 164 is an NPN transistor (not shown) provided in the primary output interface circuit 126. Is supplied, the base current of the output transistor 161, which is a PNP transistor, is supplied. The stabilization resistor 165 is connected between the emitter terminal and the base terminal of the output transistor 161, and the open circuit dark current of the output transistor 161 is supplied. It is what suppresses.
When the output transistor 161 is an NPN transistor provided on the ground circuit side, a pull-up resistor is used instead of the pull-down resistor 163, and the output logic when the output transistor is open is set to a logic level “ “H” is fixed.

The output transistor 171 constituting the first output element module 32b of the output element module 117 is an N-channel CMOS-FET type transistor that drives a large current electric load in the in-vehicle electric load group 107, and the first output voltage Vcc. The driving transistor 172 fed from the PNP transistor is a PNP transistor, the driving resistor 173 is connected between the collector terminal of the driving transistor 172 and the gate terminal of the output transistor 171, and the stable resistor 174 is connected to the gate terminal and the source of the output transistor 171. The drive resistor 175 is connected between the NPN transistor (not shown) in the primary output interface circuit 126 and the base terminal of the drive transistor 172, and the stable resistor 176 is connected to the emitter terminal and the base of the drive transistor 172. Between terminals It is connected.
The output transistor 171 is, for example, a module of 18 transistors for driving various high-current electric loads 107, and a drive command is supplied from the primary output interface circuit 126 to each output transistor. It has become so.

The monitor circuit 177 detects the presence / absence of disconnection / short circuit / overheating abnormality for a large number of output transistors 171 and serially transmits the detection result to the microprocessor 121 via the serial / parallel converter 178.
The pull-up resistor 179 is for connecting the drain terminal of the output transistor 171 to the main power supply voltage Vb.
The bypass capacitor 35b is between the ground terminal of the first output element module 32b and the ground terminal of the integrated circuit element 127 and is connected by a connection pattern 412b described later.
The first output element module 32b drives various electric loads including, for example, a fuel injection solenoid valve (not shown), and the second output element module 32c forms an H-type bridge circuit. The motor for controlling the degree is controlled.

Next, FIG. 3 which is a housing assembly structure diagram of the multilayer electronic substrate of the in-vehicle electronic control device 100 will be described.
In FIG. 3, the on-vehicle electronic control device 100 is configured by a multilayer electronic board 30 </ b> A that is hermetically sandwiched between a base member 10 and a cover member 20. For example, the base member 10, which is a high heat conductive member formed by aluminum die casting, is attached and fixed to the vehicle body by four mounting legs 11. The base member 10 is provided with a contour outer peripheral portion 12 and a heat transfer medium portion 13 which is a protrusion pedestal portion, and a planar pattern provided on the back surface layer of the multilayer electronic substrate 30A is a heat conductive adhesive or heat conductive material. Heat transfer to the heat transfer medium section 13 through the conductive sheet 14.
The heat radiation electrode of the constant voltage power circuit element 31a, which is a heat generating component, is soldered to a planar pattern provided on the surface layer of the multilayer electronic substrate 30A, and the back surface layer connected to the planar pattern by a number of through-hole platings. A planar pattern faces the heat transfer medium part 13. The cover member 20 includes an annular wall portion 21 and a canopy portion 22, and a connector housing 23 </ b> A is integrally formed on one surface of the annular wall portion 21.

One end of a large number of connection pins 24 is press-fitted into the connector housing 23A, and the other end of the connection pins 24 is soldered to the multilayer electronic board 30A.
After the waterproof sealing material 25 is applied to the outer periphery of the cover member 20 integrated by soldering the connection pins 24 to the multilayer electronic substrate 30A on which a large number of electronic components are mounted, the base member 10 The outer peripheral portion 12 is fitted and fixed with a fixing screw (not shown).
In the type in which the canopy portion 22 of the cover member 20 is opened and fixed by screwing, the connection between the numerous connection pins 24 and the multilayer electronic substrate 30A can be connected by wire bonding.

Next, FIG. 4 which is a substrate surface view through which the ground layer of the multilayer electronic substrate 30A is seen will be described.
In FIG. 4, the multilayer electronic board 30A has a rectangular shape, and the control circuit element 120 and the input / output interface circuit 34 shown in FIG. 1 are mounted in the central area of the surface layer that is the component mounting surface, and the left end area. A power supply capacitor 32a connected between the first and second output element modules 32b and 32c and the input power supply terminal and bypass capacitors 35b and 35c described later are mounted, and the right end region is connected between the input power supply terminals. A power supply capacitor 31b, a constant voltage power supply circuit element 31a composed of a plurality of power transistors, and a plurality of power supply capacitors 31c connected between output power supply terminals are mounted. Is provided with a connector housing 23A.
As a see-through ground layer, a planar ground pattern is partitioned and separated by a partition slit 422 into a power ground region 421 and a signal ground region 423, and the power ground region 421 in a specific connection region 424 without the partition slit 422. And the signal ground region 423 are integrally connected to each other. Further, the connection width in the specific connection region 424 is shorter than the length of the partition slit 422.
The power ground region 421 occupies the left end region, the lower end region, and the lower half of the right end region in the ground layer of the multilayer electronic substrate 30A, and the input circuit portions of the output element module 117 (32b, 32c) and the constant voltage power circuit element 31a On the other hand, the signal ground region 423 is in the central region, and the control circuit element 120 and the input / output interface circuit 34 are mounted.
In the specific connection region 424 where the power ground region 421 and the signal ground region 423 are connected, the output circuit portion of the constant voltage power circuit element 31a is located.

The bypass capacitors 35b and 35c are connected between the first and second output element modules 32b and 32c and the input / output interface circuit 34 or the ground terminal of the control circuit element 120 by connection patterns 412b and 412c.
Further, the external connection terminal group in which the other ends of the numerous connection pins 24 are connected by soldering or wire bonding is disposed in the power ground region 421, and the signal ground region 423 exists in the vicinity, or the power ground region The ground terminals in the external connection terminal group are connected to the ground pattern of the power ground area 421.
The external connection connector 54A is inserted into the connector housing 23A and connected to the in-vehicle battery 101, the in-vehicle sensor groups 104 and 105, and the in-vehicle electrical load groups 106 and 107 through a number of external wires.

Next, FIG. 5, which is a configuration diagram of the wiring pattern surface of the multilayer electronic substrate 30A, will be described.
In FIG. 5, wiring patterns to be a front surface signal layer 41, a ground layer 42, a power supply layer 43, and a back surface signal layer 44 are provided on both surfaces of the insulating base layers 30a, 30b, and 30c constituting the multilayer electronic substrate 30A. Yes.
The surface signal layer 41 serving as a component mounting surface includes a surface copper foil pattern to which heat radiation electrodes of heat-generating components are in close contact, and is a surface layer in which one or both of other linear input signal patterns and linear output patterns are mixed. The back surface signal layer 44 has a surface copper layer pattern on the back surface layer connected to the surface copper layer pattern of the front surface signal layer 41 by through-hole plating, and any of the other linear output signal patterns or linear input patterns. Either one or both of them are mixed, and the planar copper foil pattern on the back layer side is adjacent to the heat transfer medium portion 13.

The ground layer 42, which is one of the intermediate layers serving as the first specific layer, is a layer mainly composed of a planar ground pattern as described with reference to FIG. The power supply layer 43, which is another intermediate layer serving as the second specific layer, is a layer mainly composed of a planar or linear power supply pattern, and the main power supply voltage Vb is applied by the dividing slit 432. The input power supply pattern 431 and the output power supply pattern 433 are divided into regions, and the output power supply pattern 433 is further divided into a plurality of patterns to which the first to fifth output voltages are applied. The input power supply pattern 431 is connected to the positive terminal of the in-vehicle battery 101, and the output power supply pattern 433 is connected to the positive terminal output circuit of the constant voltage power supply circuit element 31a.
Through-hole plating is used to connect the wiring patterns of each layer to each other, and independent circular copper foil lands are provided in layers that do not require connection. For example, the lower left terminal of the first output element module 32 b is connected to the input signal pattern 431 of the surface signal layer 41 and the power supply layer 43. Similarly, the upper left terminal of the first output element module 32b is connected to the power ground region 421 of the surface signal layer 41 and the ground layer 42, and the connection pattern 412b provided on the bypass capacitor 35b and the surface signal layer 41 is connected. And is connected to the signal ground region 423 of the ground layer 42.

In FIG. 6, which is a cross-sectional view of the multilayer electronic substrate 30A, an external connection terminal group 411 is provided on the surface signal layer 41, and connection pins 24 that mainly handle input signals are connected thereto. The external connection terminal group 441 is provided on the back signal layer 44 and is connected to the connection pins 24 that mainly handle output signals.
However, as a matter of fact, the input / output signal terminals are mixed in the front surface signal layer 41 and the back surface signal layer 44, and the connection pins 24 connected to the external connection terminal groups 411 and 441 are also connected to the dispersed positions. It has become.

The operation of the ground circuit of the electronic board of the in-vehicle electronic control device according to the first embodiment configured as described above will be described.
1 and 2 showing an outline of an electronic circuit mounted on the multilayer electronic substrate 30A and externally connected devices, a vehicle body grounding part 109a to which a ground terminal of the in-vehicle electronic control device 100 and a negative terminal of the in-vehicle battery 101 are connected. The resistance value of the ground wiring 109b that connects them is, for example, about 5 to 10 mΩ, but in reality, the propagation delay of the high-speed operation signal occurs due to the influence of the inductance component, and the AC impedance for the high-frequency signal is larger. Thus, the ground potential of the multilayer electronic substrate 30A varies greatly.
Similarly, since the ground potentials of the in-vehicle sensor groups 104 and 105 and the in-vehicle electric load groups 106 and 107 also fluctuate, it is suitable for exchanging signals between the input / output signal source having the fluctuating potential and the microprocessor. Need attention.
In general, with respect to the analog sensor 104 that handles a high-precision analog signal that requires a resolution of several mV, an analog ground line is connected to each other to suppress a change in ground potential.

Further, the noise signal is cut by the positive and negative clip diodes 144 and 145 and the analog signal smoothed by the noise filter 143 is input to the multi-channel AD converter 124, and the digital conversion value is taken into the microprocessor 121.
Further, in the switch sensor 105 and some electric loads, a hysteresis circuit 155 is provided on the signal receiving side so that the output logic does not invert even if the signal level fluctuates within a certain range, or there is a response delay with respect to the input signal. A noise filter 152 is provided in a range that does not cause a problem.
On the other hand, in the multilayer electronic substrate, the pattern resistance is suppressed by using a planar ground pattern. However, the pattern resistance still has a value of several tens percent of the ground wiring 109b and a large load current. It is necessary to pay attention to fluctuations in ground potential due to intermittent operation. In particular, an electronic board mounted with high density is easily affected by inductive noise from the wiring pattern, and care must be taken so that the large current pattern and the minute current pattern are not adjacently wired in parallel.

4 to 6 showing the characteristic substrate configuration of the present invention, the ground pattern is not divided into one solid ground, but is separated into a power ground region 421 and a signal ground region 423, and each ground region is provided on the component mounting surface. Circuit components suitable for the above are installed. Moreover, the connector housing 23A is installed at a position across both ground areas so that the connection to the power ground system circuit component and the connection to the signal ground system circuit component can be connected without crossing.
In addition, with the separation of the power ground region 421 and the signal ground region 423, the potential fluctuation of the signal ground region 423 due to the interruption of the large load current is suppressed, but the input / output interface circuit 34 and the first The risk of noise malfunction increases when signals are transferred between the second output element modules 32b and 32c.
In order to solve this problem, the ground terminals of the first and second output element modules 32b and 32c connected to the ground pattern of the power ground region 421 and the input connected to the ground pattern of the signal ground region 423 are used. Bypass capacitors 35b and 35c are connected between the output interface circuit 34 and the ground terminal of the control circuit element 120.

As a result, the bypass capacitors 35b and 35c connect the power ground region 421 and the signal ground region 423 with capacitors, but the connection patterns 412b provided in the signal layer to connect between target terminals, Pin points are connected via 412c. Therefore, the effectiveness can be improved compared to the general concept of simply connecting a bypass capacitor somewhere between the two ground patterns.
As the bypass capacitors 35b and 35c, ceramic capacitors having a capacitance of 0.1 to 0.01 μF, for example, are used. The parasitic internal inductance of the ceramic capacitors is Lc, the capacitance is Ci, and the line inductance of the connection pattern is Lp. , When the center frequency of the main induced noise generated between the negative terminal of the output element module and the negative terminal of the control circuit element 120 or the input / output interface circuit 34 is fi,
1 / [(2πfi) ² × (Lc + Lp)] ≦ Ci (1)
It is desirable to use a capacitor having a capacity that satisfies the above relationship.
As a result, the impedance of the bypass capacitors 35b and 35c in the vicinity of the center frequency fi becomes several Ω or less, and noise malfunction can be prevented.

The main points and features of the on-vehicle electronic control device of the first embodiment described above will be described.
According to the on-vehicle electronic control device according to Embodiment 1 of the present invention, the constant voltage power circuit element 31a of the power module 110 that is supplied with power from the on-vehicle battery 101 and generates a predetermined stabilization voltage, the switch sensor 105, and the analog sensor 104. Output element modules 32b and 32c for driving a large current load, which are open / close elements for driving and controlling various in-vehicle electric load groups 106 and 107 in response to the operating state of the in-vehicle sensor groups 104 and 105 including the microprocessor 121 The control circuit element 120 and the input / output interface circuit 34 which are driven by a stabilizing voltage are mounted, and an external connection connector 54A connected to various in-vehicle electric load groups 106 and 107 and in-vehicle sensor groups 104 and 105 is provided. A multilayer electronic substrate 30A to be detachably connected, the first of the multilayer electronic substrate 30A Planar ground pattern located fixed layer is divided roughly by the dividing slit 422, it is isolated in the power ground region 421 and the signal ground region 423 which are connected to one another in a particular connection region 424.

With power ground area 421 is intended to be connected to the negative terminal of the vehicle battery 101, an input circuit portion of the power output element module 32b to the ground region 421, 32c and the constant-voltage power supply circuit elements 31a are mounted . Input-output interface circuit 34 which includes an input interface circuit 114 is mounted relative to the control circuit element 120 and the analog sensor 104 to the signal ground region 423.
For at least a part of the analog sensors 104 in the in-vehicle sensor groups 104 and 105, the signal ground region 423 and the negative terminal of the analog sensor are connected by the signal ground wiring 108a, and the power ground region 421 and the signal are connected to each other. The specific connection region 424 with the ground region 423 is located in the output circuit portion of the constant voltage power supply circuit element 31a, and the connection width in the specific connection region 424 is shorter than the length of the partitioning slit 422.
Therefore, some analog sensors that require high accuracy are configured so that the negative terminal potential level is the same by the signal ground line 108a, and the influence of potential fluctuations due to intermittent load current is eliminated. In addition, the ground potential of the signal ground region 423 hardly changes with respect to the fluctuation of the load current due to the opening / closing operation of the output element modules 32b and 32c, which are load driving switching elements mounted in the power ground region 421. This has the effect of suppressing malfunctions related to the exchange of monitoring and control signals between the microprocessor 121 mounted on the 423 and the output element modules 32b and 32c mounted on the power ground area 421.

The multilayer electronic substrate 30A has a rectangular shape, and external connection terminal groups 411 and 441 to which a large number of connection pins 24 that contact the external connection connector 54A are connected by soldering or wire bonding are provided on one side of the rectangular shape. .
The external connection terminal groups 411 and 441 are disposed in the power ground region 421, and the signal ground region 423 exists in the vicinity of the external connection terminal group 411 or 441, and is disposed at a position straddling the power ground region 421 and the signal ground region 423. A ground terminal in the external connection terminal group is connected to the ground pattern of the power ground region 421.
Therefore, the input signal lines connected to the in-vehicle sensor groups 104 and 105 can be easily connected to the input interface circuit 34 mounted in the signal ground region 423 and are connected to the in-vehicle electric load groups 106 and 107. The output signal lines can be directly connected to the output element modules 32b and 32c mounted in the power ground region 421, and the noise input / output signal lines are prevented from intermingling and noise malfunction is suppressed. There are features that can be done.

Planar power supply pattern positioned in the second particular layer of a multilayer electronic substrate 30A is divided in the input power supply pattern 431 and an output power pattern 4 33 by dividing slit 432, the input power supply pattern 431 of the in-vehicle battery 101 Connected to the positive terminal.
Dividing the output power pattern 4 33 together are intended to be connected to the positive terminal output circuit of the constant voltage power supply circuit elements 31a, the output power pattern 4 33 to multiple output power supply pattern corresponds to the output voltage of the heterologous Has been.
Therefore, there is a feature that it is possible to prevent noise malfunctions by avoiding the intersection of the input signal circuit and the output circuit. Further, there is a feature that power supply to the low voltage memory built in the microprocessor 121 and a weak power supply circuit to the battery backup memory 123b after the power switch 103 is opened can be performed by an independent power supply pattern.

The multilayer electronic substrate 30A is a four-layer substrate constituted by three insulating base layers 30a, 30b, 30c and four wiring pattern surfaces 41, 42, 43, 44.
The surface signal layer 41 serving as a component mounting surface includes a planar copper foil pattern to which heat radiation electrodes of heat-generating components are in close contact, and a surface layer in which one or both of other linear input signal patterns and linear output patterns are mixed. It has become. The back surface signal layer 44 is connected to the planar copper foil pattern of the front surface signal layer 41, includes the planar copper foil pattern adjacent to the heat transfer medium section 13, and is either a linear output signal pattern or a linear input pattern. One or both are mixed in the back layer.
The intermediate ground layer 42 that is the first specific layer is a layer mainly composed of a planar ground pattern, and is divided into a power ground region 421 and a signal ground region 423 by a partition slit 422, and The power ground region 421 and the signal ground region 423 are connected to each other in the specific connection region 424 having no slit for use.
The intermediate power supply layer 43 serving as the second specific layer is a layer mainly composed of a planar or linear power supply pattern, and is divided into regions of the input power supply pattern 431 and the output power supply pattern 433 by the dividing slit 432. ing.
Therefore, it is easy to conduct continuity inspection of the multilayer electronic substrate in the manufacturing process, and in the practical state, it is possible to efficiently dissipate heat from the planar output pattern to the heat radiating part via the heat conductive sheet or the heat conductive adhesive. There is.

Bypass capacitors 35b and 35c are disposed in the vicinity of the output element modules 32b and 32c mounted in the power ground region 421. The bypass capacitors 35b and 35c are connected between the negative terminals of the output element modules 32b and 32c and the negative terminal of the control circuit element 120 or the input / output interface circuit 34, and are provided in the signal layers 41 and 44 of the multilayer electronic board 30A. The patterns 412b and 412c are connected.
Therefore, it is possible to directly suppress potential fluctuations between the negative terminals of the output element modules 32b and 32c and the negative terminal of the control circuit element 120 or the input / output interface circuit 34 against high-frequency / high-voltage noise, thereby causing malfunction of signal transmission / reception, particularly logic. There is a feature that it is possible to prevent the malfunctioning state from continuing by suppressing the disappearance of the storage logic of the latch signal storing the state.

Ceramic capacitors having a capacitance of 0.1 to 0.01 μF are used for the bypass capacitors 35b and 35c. The parasitic internal inductance of the ceramic capacitor is Lc, the capacitance is Ci, the line inductance of the connection patterns 412b and 412c is Lp, the negative terminals of the output element modules 32b and 32c and the negative terminal of the control circuit element 120 or the input / output interface circuit 34. When the center frequency of the main induction noise generated between
1 / (2πfi) ² × (Lc + Lp)] ≦ Ci (1)
A capacitor having a capacity satisfying the above relationship is used.
Therefore, the negative terminals of the output element modules 32b and 32c and the negative terminal of the control circuit element 120 or the input / output interface circuit 34 are connected to the high frequency noise with low impedance by the bypass capacitors 35b and 35c. There is a feature that can be suppressed.

Among the various on-vehicle electric load groups 106 and 107, the load driving transistor 106b is used outside the multilayer electronic substrate 30A, and is output directly from the input / output interface circuit 34 without passing through the output element modules 32b and 32c. Regarding the specific electrical load 106 a corresponding to the current electrical load 106, the output interface circuit 116 in the input / output interface circuit 34 includes an output transistor 161 whose logic level is determined by a pull-up resistor or a pull-down resistor 163 and a short-circuit protection series resistor 162. In addition, the input circuit of the load driving transistor 106b for driving the specific electric load 106a is provided with respect to the fluctuation of the negative terminal potential of the specific electric load 106a and the fluctuation of the ground potential of the signal ground region 423 of the multilayer electronic substrate 30A. The output logic changes It provided hysteresis circuit 106c to prevent.
Therefore, even if the negative potential of the output interface circuit 116 in the multilayer electronic substrate and the negative potential of the load driving transistor 106b change, the load driving can be performed stably.

The switch interface 105 for the switch sensor in the input / output interface circuit 34 is related to the switch sensor 105a in the in-vehicle sensor group 104, 105, which uses the switching element 105a by an electrical contact or transistor that opens and closes. A pull-up resistor 151 or a pull-down resistor for determining a logic level in response to an opening / closing operation, a noise filter 152 as a low-pass filter, and a hysteresis circuit 155 are provided. The hysteresis circuit 155 has a negative terminal potential of the switch sensor 105. This is a positive feedback circuit configured so that the output logic does not change with respect to the fluctuation and the fluctuation of the ground potential of the signal ground region 423 of the multilayer electronic substrate 30A.
Therefore, even if the negative potential of the input interface circuit 115 in the multilayer electronic substrate fluctuates, the sensor open / closed state can be correctly input.

Embodiment 2. FIG.
Next, an in-vehicle electronic control apparatus according to Embodiment 2 of the present invention will be described with reference to FIGS. FIG. 7 is a front view of the substrate through which the ground layer of the multilayer electronic substrate of the in-vehicle electronic control device is seen, and FIG. 8 is a cross-sectional view of the multilayer electronic substrate.
The overall circuit diagram of the in-vehicle electronic control device 100 using the multilayer electronic substrate 30B according to the second embodiment, the partial detailed view of the input / output interface circuit, and the housing assembly structure diagram are the same as those in the first embodiment. This is the same as FIG. 1, FIG. 2, and FIG. A 6-layer multilayer electronic board 30B is used instead of the 4-layer multilayer electronic board 30A, a connector housing 23B is used instead of the connector housing 23A, and an external connection connector 54B is used instead of the external connection connector 54A. ing. Moreover, in each figure, the same code | symbol has shown the same or an equivalent part.

In FIG. 7 which shows the substrate surface view of the multilayer electronic substrate in the second embodiment, the outer peripheral annular pattern 425 is provided at the outer periphery of each layer of the multilayer electronic substrate 30B separately from the other wiring patterns. The peripheral annular pattern 425 of each layer is connected to each other by through-hole plating, and the vehicle body grounding part 109c in the vicinity where the in-vehicle electronic control device 100 is installed via the connection pin 24, the external connection connector 54B, and the ground wiring 109d. The high-pressure static electricity generated in the cover member 20 is discharged to the vehicle body to prevent electrostatic breakdown of the electronic components mounted on the multilayer electronic substrate 30B.
In the multilayer electronic substrate 30B, the power ground regions 421 are located at the left and right ends and the lower end of the electronic substrate. The power ground regions 421 are separated from the signal ground regions 423 located at the center by left and right partitioning slits 422a and 422b. The specific connection area 424 connects each other.

One of the two power supply capacitors 32a, the first output element module 32b, and the bypass capacitor 35b are mounted in the left power ground region 421, and two used power supplies are mounted in the right power ground region 421. The other capacitor 32a, the second output element module 32c, and the bypass capacitor 35c are mounted, and a connector housing 23B is provided in the lower power ground area 421.
A power supply capacitor 31b, a constant voltage power supply circuit element 31a, and a power supply capacitor 31c are mounted in the lower center part, and an output portion of the constant voltage power supply circuit element 31a is a specific connection region 424. The lower part of the signal ground area 423 on which the control circuit element 120 and the input / output interface circuit 34 are mounted is adjacent to the external connection terminal group in which the connector housing 23B is disposed.

In FIG. 8 showing the cross-sectional view of the multilayer electronic substrate, the multilayer electronic substrate 30B is laminated in the order of the insulating base layers 30a, 30d, 30b, 30e, 30c, and the surface signal layer 41, the ground layer 42, and the intermediate signal layer 45. In addition, a wiring pattern to be an intermediate signal layer 46, a power supply layer 43, and a back signal layer 44 is provided.
A group of external connection terminals 451 connected to the connection pins 24 is provided in the intermediate signal layer 45, and input signal terminals are mainly connected thereto. A group of external connection terminals 461 connected to the connection pins 24 is provided in the intermediate signal layer 46, and output signal terminals are mainly connected thereto.
When a five-layer substrate is used instead of the six-layer substrate shown in FIG. 8, the multilayer electronic substrate is laminated in the order of the insulating base layers 30a, 30b, 30d, 30c, and the surface signal layer 41, the ground Wiring patterns to be a layer 42, an intermediate signal layer 45, a power supply layer 43, and a back signal layer 44 are provided, and input / output external connection terminal groups 451 connected to the connection pins 24 are provided in the intermediate signal layer 45. It has become.

The main points and features of the on-vehicle electronic control device of the second embodiment described above will be described.
According to the in-vehicle electronic control device according to the second embodiment of the present invention, the in-vehicle sensor including the constant voltage power circuit element 31a that is supplied with power from the in-vehicle battery 101 and generates a predetermined stabilized voltage, the switch sensor 105, and the analog sensor 104. The output element modules 32b and 32c for driving a large current load, which are switching elements for controlling the driving of various on-vehicle electric load groups 106 and 107 in response to the operating state of the groups 104 and 105, and the microprocessor 121 are included and stable. The control circuit element 120 driven by the control voltage and the input / output interface circuit 34 are mounted, and the various on-vehicle electric load groups 106 and 107 and the external connection connector 54B connected to the on-vehicle sensor groups 104 and 105 are connected and disconnected. A multilayer electronic substrate 30B having a planar shape located in the first specific layer of the multilayer electronic substrate 30B Land pattern is divided roughly partitioning slits 422a, by 422b, it is isolated in the power ground region 421 and the signal ground region 423 which are connected to one another in a particular connection region 424.

With power ground area 421 is intended to be connected to the negative terminal of the vehicle battery 101, an input circuit portion of the power output element module 32b to the ground region 421, 32c and the constant-voltage power supply circuit elements 31a are mounted . Input-output interface circuit 34 which includes an input interface circuit 114 is mounted relative to the control circuit element 120 and the analog sensor 104 to the signal ground region 423.
For at least a part of the analog sensors 104 in the in-vehicle sensor groups 104 and 105, the signal ground region 423 and the negative terminal of the analog sensor are connected by the signal ground wiring 108a, and the power ground region 421 and the signal are connected to each other. The specific connection region 424 with the ground region 423 is located in the output circuit portion of the constant voltage power supply circuit element 31a, and the connection width in the specific connection region 424 is shorter than the length of the partitioning slits 422a and 422b.
Therefore, some analog sensors that require high accuracy are configured so that the negative terminal potential level is the same by the signal ground line 108a, and the influence of potential fluctuations due to intermittent load current is eliminated. In addition, the ground potential of the signal ground region 423 hardly changes with respect to the fluctuation of the load current due to the opening / closing operation of the output element modules 32b and 32c, which are load driving switching elements mounted in the power ground region 421. This has the effect of suppressing malfunctions related to the exchange of monitoring and control signals between the microprocessor 121 mounted on the 423 and the output element modules 32b and 32c mounted on the power ground area 421.

The multilayer electronic substrate 30B has a rectangular shape, and external connection terminal groups 451 and 461 to which a large number of connection pins 24 that contact the external connection connector 54B are connected by soldering or wire bonding are provided on one side of the rectangular shape. .
The external connection terminal groups 451 and 461 are disposed in the power ground region 421, and the signal ground region 423 exists in the vicinity of the external connection terminal group 451 or 461, and is disposed in a position straddling the power ground region 421 and the signal ground region 423. A ground terminal in the external connection terminal group is connected to the ground pattern of the power ground region 421.
Therefore, the input signal lines connected to the in-vehicle sensor groups 104 and 105 can be easily connected to the input interface circuits 114 and 115 mounted in the signal ground region 423, and connected to the in-vehicle electric load groups 106 and 107. Output signal lines can be directly connected to the output element modules 32b and 32c mounted in the power ground region 421, and the input / output signal lines are prevented from intermingling to suppress noise malfunction. There are features that can.

Planar power supply pattern positioned in the second particular layer of a multilayer electronic substrate 30B is divided in the input power supply pattern 431 and an output power pattern 4 33 by dividing slit 432, the input power supply pattern 431 of the in-vehicle battery 101 Connected to the positive terminal.
Dividing the output power pattern 4 33 together are intended to be connected to the positive terminal output circuit of the constant voltage power supply circuit elements 31a, the output power pattern 4 33 to multiple output power supply pattern corresponds to the output voltage of the heterologous Has been.
Therefore, there is a feature that it is possible to prevent noise malfunctions by avoiding the intersection of the input signal circuit and the output circuit.
Further, there is a feature that power supply to the low voltage memory built in the microprocessor 121 and a weak power supply circuit to the battery backup memory 123b after the power switch 103 is opened can be performed by an independent power supply pattern.

The multilayer electronic substrate 30B is a 5-layer or 6-layer substrate to which one or two intermediate insulating base layers 30d, 30e and one or two intermediate wiring pattern surfaces 45, 46 are added, The one-layer or two-layer wiring pattern interposed between the layer 42 and the power supply layer 43 becomes intermediate signal layers 45 and 46, and there are more intermediate signal layers 45 and 46 than the other signal layers 41 and 44. The external connection terminal groups 451 and 461 are connected.
Therefore, the intermediate signal layer which is difficult to check the operation from the front surface or the back surface has a feature that can be checked from a large number of input / output terminals.

Bypass capacitors 35b and 35c are disposed in the vicinity of the output element modules 32b and 32c mounted in the power ground region 421. The bypass capacitors 35b and 35c are located between the negative terminals of the output element modules 32b and 32c and the negative terminals of the control circuit element 120 or the input / output interface circuit 34, and are connected to the signal layers 41, 44, 45, and 46 of the multilayer electronic substrate 30B. They are connected by the provided connection patterns 412b and 412c.
Therefore, it is possible to directly suppress potential fluctuations between the negative terminals of the output element modules 32b and 32c and the negative terminal of the control circuit element 120 or the input / output interface circuit 34 against high-frequency / high-voltage noise, thereby causing malfunction of signal transmission / reception, particularly logic. There is a feature that it is possible to prevent the malfunctioning state from continuing by suppressing the disappearance of the storage logic of the latch signal storing the state.

An outer peripheral annular pattern 425 separated from other wiring patterns is provided on the outer periphery of each layer of the multilayer electronic substrate 30B, and the outer peripheral annular pattern 425 of each layer is connected to each other via an external connection connector 54B. And connected to the nearby vehicle body grounding part 109c.
Accordingly, the high-voltage static electricity generated in the cover member 20 covering the multilayer electronic board is discharged to the vehicle body via the outer peripheral annular pattern 425 to protect the electronic components mounted on the multilayer electronic board, and the mounting location of the base member 10 is a resin. Even if it is a molded insulator, there is a feature that electrostatic removal can be reliably performed.

It is a whole circuit diagram of the vehicle-mounted electronic control apparatus of Embodiment 1 of this invention. FIG. 2 is a partial detail view of the input / output interface circuit shown in FIG. 1. It is a housing assembly structure diagram of an in-vehicle electronic control device. FIG. 3 is a substrate surface view seen through a ground layer of a multilayer electronic substrate in the in-vehicle electronic control device according to the first embodiment. FIG. 3 is a configuration diagram of a wiring pattern surface of the multilayer electronic substrate according to the first embodiment. FIG. 3 is a cross-sectional view of the multilayer electronic substrate according to the first embodiment. It is the board | substrate surface view which saw through the ground layer of the multilayer electronic board in the vehicle-mounted electronic control apparatus of Embodiment 2 of this invention. FIG. 6 is a cross-sectional view of a multilayer electronic substrate according to a second embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 13 Heat-transfer medium part 24 Connection pin 30A, 30B Multi-layer electronic board 30a-30e Insulating base material layer 31a Constant voltage power supply circuit element 32b First output element module 32c Second output element module 34 Input / output interface circuit 35b, 35c Bypass Capacitor
41 Front surface signal layer 42 Ground layer 43 Power supply layer 44 Back surface signal layer 45, 46 Intermediate signal layer 54A, 54B Connector for external connection 101 In-vehicle battery 104 Analog sensor (in-vehicle sensor group)
DESCRIPTION OF SYMBOLS 105 Switch sensor (vehicle-mounted sensor group) 105a Open / close element 106 Vehicle-mounted electric load group (small current) 106a Specific electric load 106b Load drive transistor 106c Hysteresis circuit 107 Vehicle-mounted electric load group (large current) 108a Signal ground wiring 109c Near body grounding Part 115 Input interface circuit 116 Output interface circuit 120 Control circuit element 121 Microprocessor 151 Pull-up resistor 152 Noise filter 155 Hysteresis circuit 161 Output transistor 162 Short-circuit protection series resistor 163 Pull-down resistor 411, 451 External connection terminal group (input) 412b, 412c Connection pattern 421 Power ground area 422 Partition slit 422a, 422b Partition slit 423 Signal ground area 42 Specific connection region 425 outer peripheral annular pattern 431 input power supply pattern 432 dividing slit 433 output power pattern 441,461 external connection terminals (output)

Claims (3)

A constant voltage power supply circuit element that generates power from a vehicle-mounted battery and generates a predetermined stabilization voltage, and an open / close for driving and controlling various vehicle-mounted electric load groups in response to the operating state of the vehicle-mounted sensor group including a switch sensor and an analog sensor An output element module for driving a large current load, which is an element, a control circuit element including a microprocessor and driven by the stabilizing voltage, and an input / output interface circuit are mounted. An in-vehicle electronic control device having a multilayer electronic board to which a connector for external connection connected to a group is detachably connected ,
The multilayer electronic substrate has at least three insulating base layers and four wiring pattern surfaces and has a rectangular shape, at least one of which is a surface signal layer and a back surface signal layer serving as a component mounting surface, and an intermediate layer Configure the ground layer and power supply layer,
Said first planar ground pattern provided on the ground layer located in a particular intermediate layer of a multilayer electronic substrate, while being divided isolated power ground region and signal ground region by a partition slit, said partitioning slit the power ground region and the signal ground region being connected to each other at a particular connection area without,
The power ground region is provided on an outer peripheral side of the multilayer electronic board on which the external connection connector is mounted and an adjacent side orthogonal to the outer peripheral side, and the power ground region is provided on the vehicle-mounted via the external connection connector. In addition to being connected to the negative terminal of the battery, the output circuit module and the input circuit unit of the constant voltage power circuit element are mounted in the power ground area, and the control circuit element and the analog sensor are mounted in the signal ground area. The input / output interface circuit including the input interface circuit is mounted,
The planar power supply pattern provided in the power supply layer located in the second specific intermediate layer of the multilayer electronic substrate is divided into an input power supply pattern and an output power supply pattern region by a dividing slit, and the input power supply pattern is Connected to the positive terminal of the in-vehicle battery, the output power supply pattern is connected to the positive terminal output circuit of the constant voltage power supply circuit element, and the region of the output power supply pattern has a plurality of output power supply patterns corresponding to different output voltages. Is divided into
The output element module includes a monitor circuit, and the monitor circuit includes a latch circuit that detects and stores the presence or absence of disconnection or short circuit of the output transistor constituting the output element module or an overheat abnormality.
There is a bypass in the vicinity of the output element module mounted in the power ground area.
A capacitor is disposed, and the bypass capacitor is connected between a negative terminal of the output element module and a negative terminal of the control circuit element or the input / output interface circuit;
For at least a part of the analog sensors in the in-vehicle sensor group, the signal ground region and the negative terminal of the analog sensor are connected by a signal ground wiring, and the power ground region and the signal ground region of the particular connection region situated the output circuit of the constant voltage power supply circuit elements, connections width in the specific connection region vehicle electronic control, characterized in that it is shorter than the length of the partition slit apparatus. The multilayer electronic board is provided with an external connection terminal group in which a large number of connection pins that contact the external connection connector are connected by soldering or wire bonding on one side of the rectangular shape, and the external connection terminal group has a signal at a nearby position. vehicle electronic control unit according to claim 1, characterized in that the ground region is disposed on either present, or across a power-ground region and signal ground area position. The bypass capacitor is connected between a negative terminal of the output element module and a negative terminal of the control circuit element or the input / output interface circuit, and is connected by a connection pattern provided in a signal layer of the multilayer electronic substrate,
The bypass capacitor is a ceramic capacitor having a capacitance of 0.1 to 0.01 μF, the parasitic internal inductance of the ceramic capacitor is Lc, the capacitance is Ci, the line inductance of the connection pattern is Lp, and the output element When the center frequency of the main induction noise generated between the negative terminal of the module and the negative terminal of the control circuit element or the input / output interface circuit is fi,
1 / [(2πfi) ² × (Lc + Lp)] ≦ Ci
Vehicle electronic control unit according to claim 1 or claim 2 the capacity of the capacitor of the relationship is established, characterized in that it is used.

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