JPH1023659A - Switching-device and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it easier to handle and attach units by improving the reliability of switching by reducing adverse effects due to heating of semiconductor switches and further reducing the number of units (packages). SOLUTION: A plurality of semiconductor switches 54A to 54X are attached to the top of a radiator fin 57; and if an overcurrent flows to the semiconductor switches 54A to 54X and/or the semiconductor switches 54A to 54X are overheated, a plurality of protection circuits 55A to 55X, for protecting the semiconductor switches 54A to 54X, are housed in a package 56 by off- controlling the semiconductor switches 54A to 54X.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a switching device and a method of manufacturing the switching device, and can be applied to, for example, a switching device for selectively supplying power from a battery to each load in an automobile.

[0002]

2. Description of the Related Art In a conventional vehicle, a power supply from a battery is selectively applied to each electric component (hereinafter, this electric component is referred to as a load) in accordance with the operation of an operation switch such as an ignition key, a light switch, and an audio switch. To supply, a number of switching circuits are provided.

[0005] FIG. 5 schematically shows the structure of the battery 1.
Are connected to a junction block (J / B) 2, and operation switches SW 1, SW 2,... Disposed on an operation panel 3 are connected to the junction block 2.
Is connected. The junction block 2 is provided with switching circuits corresponding to the number of operation switches SW1, SW2,..., And each switching circuit is provided with a battery 1 according to the operation of the operation switches SW1, SW2,.
The connection between the power supply line and the electric wire connected to each load is turned on or off.

As a result, the battery power is supplied to the operation switches SW1, SW2,.
Is selectively supplied to each load according to the operation of. For example, when the headlight switch is turned on, power is supplied to the headlights 4A and 4B by turning on the power supply line from the battery 1 and the electric wire to the headlights 4A and 4B at the junction block 2. The headlights 4A and 4B are turned on.

[0005] In addition to the headlights 4A and 4B, in which power is directly supplied to the load via the junction block 2, the power is output from the junction block 2 such as motors 5A and 5B for driving power windows. Power is supplied via switching circuits 6A and 6B. This switching circuit 5A, 5B
Is controlled by the operation switches 7A and 7B.

In practice, the junction block 2 is shown in FIG.
It is configured as shown in FIG. The junction block 2 is provided with a plurality of relays L1, L2, L3,..., And these relays L1, L2, L3,.
1, there is a relay whose on / off is controlled by the direct operation switches SW1 and SW2 to directly apply a current to the load as in L2, and a relay L3 whose on / off is controlled in accordance with the state of the ignition switch 8.

The relays L1 and L2 are connected to the fusible link (FL) 9 and the fuses F1 and F from the battery.
Battery power is supplied via the power supply 2. As a result, when a large current exceeding the allowable value flows through the power supply line connecting the battery 1 and the junction block 2, the fusible link 9 is blown, and the electric wire (harness) connecting the junction block 2 and each load is allowed. When the above-described overcurrent flows, the fuses F1 and F2 are blown to prevent the entire power supply line from smoking or firing, and the overcurrent from flowing to the load. Similarly, battery power is supplied to the relay L3 from the battery 1 via the fusible link 9, and the relay L3
3 is connected to fuses F3 and F4 and relays L4 and L5.
Is connected to each of the loads 5A and 5B via the.

By the way, with the progress of semiconductor manufacturing technology in recent years, semiconductor switches having good performance and low cost have been easily available, and the relays L1, L2,. A switching circuit using a semiconductor switch instead of... Has been proposed.

This type of switching circuit generally has a protection function of protecting the semiconductor switch from overcurrent or overheating. When a current exceeding the rated current flows through the semiconductor switch or when the semiconductor switch reaches a specified temperature or higher. When the temperature rises, the semiconductor switching is forcibly turned off to protect the semiconductor switch.

FIG. 7 shows a switching circuit 30 called an intelligent power switch as an example of a switching circuit using the semiconductor switch. The switching circuit 30 is connected to the position of each of the relays L1, L2,... Instead of each of the relays L1, L2,. For example, a case where the switching circuit 30 is connected in place of the relay L1 will be described.
Is connected to the fuse F1 (FIG. 6), and the output terminal 13 is connected to the load 4A. An operation switch SW1 is connected to the control signal input terminal 14. In the case of the switching circuit 30, when the operation switch SW1 is actually turned on, the operation signal S is input to the control signal input terminal 14.
A control voltage generator (not shown) supplies a control voltage V _{IN of} , for example, 5 [V] as an ON control signal from W1 and does not supply the control voltage V _IN when the operation switch SW1 is turned off. It is arranged between SW1 and the control signal input terminal 14.

The switching circuit 30 has an abnormal signal output section 4 for notifying the abnormality of the switching circuit 30 to the outside based on the output voltage value V _OUT from the semiconductor switch.
One. The abnormal signal output unit 41 is connected to an abnormal display unit 43 via a CPU (Central Processing Unit) 42 as shown in FIG. 5, and an overvoltage power supply voltage is applied to the semiconductor switch 32 of the switching circuit 30. When the semiconductor switch 32 is forcibly turned off by the protection function of the switching circuit 30 when an overcurrent flows or overheats, this is detected and an abnormal signal is detected.
Send to U42. Then, the CPU 42 determines what kind of abnormality has occurred in which switching circuit 30 based on the abnormality signal, and causes the abnormality display unit 43 to display the result.

Hereinafter, the configuration of the switching circuit 30 having the intelligent power switch configuration will be described.
The switching circuit 30 is πMOS-F power supply voltage V _B through a fuse F1 input terminal 12 connected to (Figure 6)
The signal is supplied to the ET 32 and the ON / OFF control of the πMOS-FET 32 is performed by the driver 33.

[0013] The switching circuit 30, an overvoltage detection circuit 34 the supply voltage V _B to detect when it is over-voltage, the drain of πMOS-FET32 - voltage value reference voltage generation based on the current value flowing between the source Circuit 33
A current detection circuit 35 for detecting an overcurrent by comparing the reference voltage Vref from A, the reference voltage Vref the temperature voltage V _T which is obtained by a temperature sensor provided in the vicinity of πMOS-FET32 (not shown) Temperature detection circuit 3 for detecting overheating of the πMOS-FET 32 by comparing
6 are provided, and the detection results of these detection circuits 34, 35, 36 are input to a logical sum NOT circuit 37. The control voltage V _IN is input to the OR circuit 37 via the inverter 38.

The output of the OR circuit 37 is supplied to the driver 33.
And to the charge pump 39. The charge pump 39 operates only when the output of the logical sum negation circuit 37 is positive logic, and raises the voltage of the power supply voltage V _DD stabilized by the regulator 40 so that the πMOS-FET 3
A drive voltage required to turn on the second device 2 is generated and supplied to the driver 33. When the output of the OR circuit 37 is positive logic, the driver 33 applies the drive voltage generated by the charge pump 39 to the πMOS-FET 32
When the output of the OR circuit 37 is negative logic, the πMOS-FET 32 is turned on without applying the driving voltage to the gate of the πMOS-FET 32. Turn off.

The switching circuit 30 supplies the output voltage V _OUT to the abnormal signal output section 41 via the inverter 44. The abnormal signal output section 41 is an n-channel MOS-
When the πMOS-FET 32 is turned on and the output voltage V _OUT is at a high voltage,
The S-FET 41A turns off. On the other hand, πMO
When the S-FET 32 is turned off and the output voltage V _OUT is low, the MOS-FET 41A turns on. Also, the drain terminal 41B of the MOS-FET 41A
Has been pulled up.

Therefore, in the CPU 42 (FIG. 5), the MOS-
Drain terminal 41B and source terminal 41 of FET 41A
If there is no potential difference between C, it can be determined that the protection function does not work in the switching circuit 30 (that is, there is no abnormality), and accordingly, the drain terminal 41B and the source terminal 4
If there is a potential difference between 1C, it can be determined that the protection function is working on the switching circuit 30 (that is, there is an abnormality).

The switching circuit 30 has a one-chip configuration.

[0018]

By the way, in a switching circuit using a semiconductor switch like the switching circuit 30 described above, a semiconductor switch (πMOS
Since the power supply current of about 5 to 50 [A] flows through the (FET) 32, the temperature of the semiconductor switch 32 rises, and the heat is conducted to circuit parts other than the semiconductor switch 32.

As a result, a circuit portion (driver 33, overcurrent detection circuit 34, current detection circuit 3
5 and the like (hereinafter, this circuit portion is referred to as a protection circuit because it has a function of protecting the semiconductor switch from overcurrent and overheating).
When the temperature of the protection circuit rises, the operation of the protection circuit may be deteriorated or may malfunction.

The deterioration of the performance of the protection circuit directly leads to the malfunction of the load supplied with the power from the switching circuit. Therefore, there is a problem that the reliability of the entire device using the switching circuit is reduced. there were.

Here, an intelligent power switch 45 as shown in FIG. 8 has been proposed as an intelligent power switch which is relatively insensitive to heat from such a semiconductor switch. The intelligent power switch 45 includes a semiconductor chip 46 on which a semiconductor switch is formed and a semiconductor chip 47 on which a protection circuit is formed.
Is formed as a separate chip, so that heat generated from the semiconductor switch is not easily conducted to the protection circuit.

The intelligent power switch 45
Since the semiconductor chip 46 on which the semiconductor switch is formed is mounted on the radiation fins 49 together with the semiconductor chip 47 on which the protection circuit is formed, heat generated from the semiconductor switch can be effectively radiated.

However, even if the intelligent power switch 45 as shown in FIG. 8 is used, it cannot be said that the adverse effect on the protection circuit due to heat generated from the semiconductor switch can be sufficiently prevented.

Further, in an automobile or the like, a very large number of intelligent power switches are used. For example, when an intelligent power switch 45 having a configuration as shown in FIG. 8 is used, FIG.
Has to be attached one by one, which is very troublesome. There is also a problem that the number of units becomes very large.

The present invention has been made in consideration of the above points, and further improves the reliability of switching by further reducing the adverse effect due to heat generation of a semiconductor switch, and furthermore, the handling of units by reducing the number of units. Another object of the present invention is to propose a switching device and a method for manufacturing the switching device, which can facilitate installation.

[0026]

According to a first aspect of the present invention, there is provided a switching device which is turned on in response to a control input to a control input terminal and connects a power supply to an output terminal. A semiconductor switch to be supplied to the load, and when an overcurrent flows through the semiconductor switch and / or when the semiconductor switch is overheated, a signal is output to a control input terminal to turn off the semiconductor switch, thereby controlling the semiconductor switch. In a switching device having a protection circuit for protecting a semiconductor switch, the semiconductor switch and the protection circuit are formed on another semiconductor chip, and the semiconductor chip on which the semiconductor switch is formed and the semiconductor on which the protection circuit is formed The chips are housed in separate packages.

In the above configuration, since the semiconductor switch and the protection circuit are separated by the package, it is difficult for the heat generated in the semiconductor switch to be conducted to the protection circuit.

According to a second aspect of the present invention, in the switching device, a plurality of semiconductor chips on which the semiconductor switches are formed are housed in a package for housing the semiconductor chips on which the semiconductor switches are formed, and a protection circuit is formed. A plurality of semiconductor chips on which a protection circuit is formed are accommodated in a package for accommodating the implemented semiconductor chips.

In the above configuration, the number of units (packages) can be significantly reduced as compared with the case where semiconductor switches and corresponding protection circuits are collected one by one and unitized (packaged). . For example, if a semiconductor switch and a protection circuit for driving ten loads are to be realized by a conventional configuration as shown in FIG. 8, the total number of units is ten.
On the other hand, according to the present invention, a total of two units (packages) can drive 10 or more loads. As a result, handling and mounting of the unit is facilitated.

Further, in the switching device according to the third aspect, a plurality of semiconductor switches are formed in the same chip on the semiconductor chip on which the semiconductor switches are formed.

In the above configuration, a plurality of semiconductor switches are packaged in one package only by packaging one semiconductor chip in one package, and a plurality of semiconductor switches are packaged in one package. The workability at the time of storage in a storage device can be improved.

According to a fourth aspect of the present invention, in the switching device, a plurality of protection circuits are formed in the same chip on the semiconductor chip on which the protection circuits are formed.

In the above configuration, just by packaging one semiconductor chip in one package, a plurality of protection circuits are packaged in one package, and a plurality of protection circuits are packaged in one package. The workability at the time of storage in a storage device can be improved.

According to a fifth aspect of the present invention, in the switching device, a plurality of semiconductor switches are formed in the same chip on the semiconductor chip on which the semiconductor switch is formed, and the semiconductor chip on which the protection circuit is formed is formed on the semiconductor chip. , A plurality of protection circuits are formed in the same chip.

In the above configuration, the operability when housing a plurality of semiconductor switches in one package and the operability when housing a plurality of protection circuits in one package can be improved. .

A switching device according to a sixth aspect of the present invention includes a plurality of semiconductor switches which are turned on in response to a control input to a control input terminal and supply power to a load connected to an output terminal, and each of the semiconductor switches. A switching device comprising a plurality of protection circuits each of which protects a semiconductor switch by outputting a signal to a control input terminal to turn off the semiconductor switch when an overcurrent flows through the semiconductor switch and / or when the semiconductor switch overheats. In the above, the plurality of semiconductor switches and the plurality of the protection circuits are formed on another semiconductor chip, and the one or more semiconductor chips on which the plurality of semiconductor switches are formed are attached to one radiation fin. To be.

In the above configuration, since a plurality of semiconductor switches are collectively attached to one radiating fin, heat generated from the semiconductor switches can be collectively processed at one place, and heat radiation processing is facilitated. Along with
Conduction of heat to a protection circuit or the like can be suppressed. In addition, since it is rare that all the semiconductor switches are simultaneously turned on, the ratio of the radiation fins to the semiconductor switches that actually generate heat can be increased, and the radiation efficiency can be increased accordingly.

According to a seventh aspect of the present invention, in the switching device, the semiconductor chip on which the semiconductor switch is formed is provided with temperature detecting means for detecting the temperature of the semiconductor switch and providing the detection result to the protection circuit. I do.

In the above configuration, the temperature detecting means detects the temperature of the semiconductor switch on the same semiconductor chip as the semiconductor switch, so that the temperature of the semiconductor switch can be accurately detected. As a result, the overheat protection operation by the protection circuit becomes favorable in which the temperature of the semiconductor switch is accurately reflected.

According to a eighth aspect of the present invention, there is provided a method for manufacturing a switching device, comprising: a semiconductor switch which is turned on in response to a control input to a control input terminal to supply power to a load connected to an output terminal; In a method of manufacturing a switching device having a protection circuit that protects a semiconductor switch by outputting a signal to a control input terminal and controlling the semiconductor switch to be turned off when an overcurrent flows and or when the semiconductor switch is overheated, After forming a plurality of semiconductor switches on a first semiconductor wafer, forming a plurality of semiconductor chips by cutting them, and after forming a plurality of protection circuits on a second semiconductor wafer, A step of forming a plurality of semiconductor chips by cutting and a plurality of semiconductor chips on which semiconductor switches are formed; And attaching the heat dissipating fins, so as to produce a plurality of semiconductor switches, the semiconductor switching device by the steps of electrically connecting the plurality of protection circuits.

As a result, semiconductor switches having the same configuration and the same chip area are formed on the same semiconductor wafer, and
Since the protection circuits having the same configuration and the same chip area are formed on the same semiconductor wafer, the area of the semiconductor wafer can be effectively used, and the production yield is improved.

According to a ninth aspect of the present invention, in the method of manufacturing a switching device, the semiconductor chip on which the semiconductor switch is formed and the semiconductor chip on which the protection circuit is formed are respectively housed in separate packages. Electrically connecting the terminal to the terminal of the package of the protection circuit.

As a result, the semiconductor switch and the protection circuit are respectively covered by the package,
It is possible to realize a switching device in which conduction of heat generated from the semiconductor switch to the protection circuit when current flows through the semiconductor switch is further suppressed.

According to a tenth aspect of the present invention, a volume adjustment for detecting an overcurrent is performed on a semiconductor chip on which a protection circuit is formed.

As a result, after forming a large number of protection circuits having the same configuration and the same chip area on the same semiconductor wafer, the volume can be adjusted for detecting an overcurrent according to the capacity of the semiconductor switch. Therefore, a protection circuit suitable for each semiconductor switch can be manufactured without lowering the yield when manufacturing the protection circuit.

[0046]

Embodiments of the present invention will be described below with reference to the drawings. (1) Basic Configuration FIG. 1 shows a basic configuration of a switching device 50 according to the present invention. In the example of FIG. 1, the switching device 50 of the present invention is used.
Is provided in the junction block (J / B) 51 of the vehicle.

The switching device 50 is connected between the power supply 52 and each of the loads 53A to 53X, and has a semiconductor switch portion 54A to 54S having a semiconductor switch for selectively supplying power to each of the loads 53A to 53X in accordance with the on / off operation.
54X and a protection circuit 5 for controlling the on / off of each semiconductor switch so as to protect the semiconductor switches provided in the semiconductor switch units 54A to 54X from overcurrent and overheating.
5A to 55X are formed on different chips, respectively. Thus, in the switching device 50, conduction of heat generated from the semiconductor switch to the protection circuits 55A to 55X can be suppressed, and as a result, the protection circuit 55A
Deterioration and malfunction due to heat of ~ 55X can be prevented.

Here, the plurality of protection circuits 55A to 55X each constituted by one chip are connected to one package 56.
Packaged together. Each of the semiconductor switch units 54A to 54A to 5
4X are each packaged, and the packaged semiconductor switch units 54A to 54A
X are collectively mounted on one heat radiation fin 57.

Thus, in the switching device 50, conduction of heat generated from the semiconductor switches of the semiconductor switch sections 54A to 54X to the protection circuits 55A to 55X can be further suppressed, and the semiconductor switch sections 54A to 54X can be further suppressed.
Since the heat generated from the 4X can be radiated to the outside through the radiation fins 57, overheating of the semiconductor switch itself can be suppressed.

Next, the overall configuration of the switching device 50 will be described. The interface (I / F) 59 includes:
A switching control signal S1 from an operation switch (not shown) corresponding to each of the loads 53A, 53B, 53C,..., 53X is input and supplied to the microcomputer 60.

The microcomputer 60 has loads 53A, 53B, 5
, 3C,..., 53X (hereinafter simply referred to as control signal S1).
) To the corresponding protection circuits 55A, 55B, 55
C,..., 55X. Here, for example, the protection circuit 5
5A, semiconductor switch 54A and shunt resistor 58A
Corresponds to the load 53A, and the protection circuit 55X, the semiconductor switch unit 54X, and the shunt resistor 58X are connected to the load 53X.
It corresponds to.

Here, the microcomputer 60, the protection circuit 55A, the semiconductor switch section 54A, the shunt resistor 58A and the load 5
The relationship between 3A is the microcomputer 60, the protection circuits 55B to 55B.
X, semiconductor switch units 54B to 54X, shunt resistor 5
8B to 58X and the loads 53B to 53X, the following description is based on the microcomputer 60, the protection circuit 55A, the semiconductor switch 54A, the shunt resistor 58A, and the load 5B.
Only the relationship of 3A will be described.

The protection circuit 55A receives the stabilized power supply voltage VDD from the regulator 61, the power supply voltage VC boosted by the charge pump 62, and boosts the voltage in response to the control signal S1A input from the microcomputer 60. By selectively applying the power supply voltage VC to the gate of the semiconductor switch in the semiconductor switch unit 54A, the semiconductor switch is turned on and off.

The protection circuit 55A receives temperature information VT indicating the temperature of the semiconductor switch section 54A from a temperature detection circuit provided in the semiconductor switch section 54A, and outputs a current flowing from the shunt resistor 58A to the semiconductor switch section 54A. By inputting the current value information SI0 indicating the magnitude of the above, it is detected whether or not the semiconductor switch is in an overheated state and whether or not an overcurrent is flowing through the semiconductor switch.

When the semiconductor switch is overheated or an overcurrent is flowing through the semiconductor switch, even when the control signal S1A indicating that the semiconductor switch is to be turned on is input from the microcomputer 60. ,
By stopping the supply of the drive voltage (ie, the boosted power supply voltage VC) to the gate of the semiconductor switch, the semiconductor switch is protected from overheating and overcurrent.

The current value information SI0 obtained from the shunt resistor 58A is converted into a voltage by the protection circuit 55A and then sent to the microcomputer 60. The microcomputer 60 determines whether power is currently supplied to the load 53A based on the voltage value. Judge. Here, the fact that the determination result that the power is not supplied to the load 53A despite the fact that the control signal S1A for instructing the protection circuit 55A to switch on is transmitted is obtained means that the protection function of the protection circuit 55A is activated. This means that the semiconductor switch in the semiconductor switch unit 53A is in the off state or the load 53A is in the open state. In such a case, the microcomputer 60 sends the abnormal signal S2 through the interface 59 to That fact is notified to an abnormality display unit (not shown) formed of, for example, an indicator lamp.

The semiconductor switch in the semiconductor switch 53A is turned on and off by the drive voltage from the protection circuit 55A.
The power supply input via 3 is output as it is. The power output from the semiconductor switch 53A is a shunt resistor 58
A is supplied to the load 53A via A.

Here, the shunt resistor 58A has a resistance value of 10
[MΩ] and a resistance tolerance of about ± 5 [%] are used, and are composed of a one-chip diffusion resistor or a polysilicon resistor. A plurality of chip shunt resistors 58A to 58X are combined into one package 64.
Packaged within.

(2) Detailed Configuration of Switching Device Next, the detailed configuration of the switching device 50 in this embodiment will be described with reference to FIG. In FIG. 2, the plurality of protection circuits 55A to 55X and the semiconductor switch units 54A to 54A in FIG.
4X, shunt resistors 58A-58X and loads 53A-5
Of the 3X, the protection circuit 55A corresponding to the load 53A, the semiconductor switch unit 54A, and the shunt resistor 58A will be described as representatives.

As shown in the figure, in the case of this embodiment, a power MOS-FET 110 is formed as a semiconductor switch in the semiconductor switch section 54A. Further, as described above, the protection circuit 55A and the semiconductor switch unit 54
A and the shunt resistor 58A are formed on separate chips.

The protection circuit 55A is roughly divided into a power MOS-FE based on a voltage across the shunt resistor 58A.
Current detection circuit 7 for detecting current value I0 flowing through T110
By comparing 0 with a voltage value corresponding to the current obtained from the current detection circuit 70 and a reference voltage corresponding to the rated current of the MOS-FET 110, it is detected whether or not an overcurrent is flowing through the MOS-FET 110. Overcurrent detection circuit 71
A logical product circuit 72 for selectively supplying a drive voltage to the gate of the MOS-FET 110 in accordance with a logical product of a detection result of the overcurrent detection circuit 71 and the control signal S1A; An overheat detection circuit 73 that detects whether the MOS-FET 110 is in an overheat state by comparing a detection voltage (corresponding to the above-described temperature information VT) corresponding to the temperature of the FET 110 with a reference voltage;
When the detection result of the overheat detection circuit 73 indicates overheating, the overheat prevention circuit 74 forcibly lowers the gate voltage of the MOS-FET 110 to turn off the MOS-FET 110.

The current detection circuit 70 obtains the current value I0 flowing through the shunt resistor 58A based on the voltage across the shunt resistor 58A. That is, the current detection circuit 70
8A is input to the non-inverting input terminal of the differential amplifier circuit 75 via the input terminal 105 and the voltage dividing resistors R1 and R2, and the voltage at the other end of the shunt resistor 58A is input to the input terminal 106 and the input resistor R3. To the inverting input terminal of the differential amplifying circuit 75 via the resistor R4 and the inverting input terminal and the output terminal of the differential amplifying circuit 75 via the resistor R4.
A voltage value corresponding to the output current value I0 from the S-FET 110 can be output. This current detection circuit 7
The detected voltage of 0 is sent to the microcomputer 60 via the output terminal 107.

The overcurrent detection circuit 71 includes a comparator 76
And a reference voltage value corresponding to the rated current of the MOS-FET 110 generated by the reference voltage generator 77 is input to the inverting input terminal. When the value exceeds the reference voltage value, the output is set to a positive potential (hereinafter, this is called positive logic,
(Zero potential is called negative logic). The output of the comparator 76 is output to the AND circuit 72 via the inverter 78.
Output to Thus, the overcurrent detection circuit 71 is
When a normal current flows through the ET 110, a positive logic is output, and when an overcurrent flows, a negative logic is output.

The AND circuit 72 inputs the control signal S1A to the AND circuit 79 via the control signal input terminal 100 and the logical value from the overcurrent detection circuit 71,
Find the logical negation result of them. Logical AND circuit 79
Is supplied to a buffer 81 via an inverter 80. Then, the output of the buffer 81 becomes M via the resistor R5.
It is supplied to the gate of the OS-FET 110.

In the AND circuit 72, for example, the control signal S1A is a positive logic (in this embodiment, the positive logic is set to about 5 [V] and the negative logic is set to 0 [V]), and When the output from the overcurrent detection circuit 71 is positive logic (indicating that there is no overcurrent), the inverter 80 outputs a signal of positive logic (a voltage value of 5 [V] in this embodiment). On the other hand, when the control signal S1A is positive logic and the output from the overcurrent detection circuit 71 is negative logic, the inverter 80 outputs a signal of negative logic (0 [V]).

As described above, the AND circuit 72 outputs the control signal S when the overcurrent detection circuit 71 obtains the logical value indicating that the overcurrent has flowed through the MOS-FET 110.
When 1A is a signal for turning off the MOS-FET 110, a negative logic signal is output.

The driving voltage VC generated by the charge pump 62 is supplied to the buffer 81 via the terminal 102, so that the gate of the MOS-FET 110 is necessary when the MOS-FET 110 is to be turned on. Voltage value is secured. That is, in the case of this example, the positive logic output from the inverter 80 is set to 5 [V], and this is level-shifted by 12 [V] by the buffer 81. As a result, the buffer output becomes 17 [V].
The power supply voltage VB in this embodiment is 12 [V].

Therefore, when the output of the inverter is positive logic, a voltage of 17 [V] is applied to the gate of the MOS-FET 110, so that the MOS-FET 110 normally operates. On the other hand, when the output of the inverter is negative logic, the output of the buffer 81 is set to the ground potential. As a result, no potential difference is obtained between the gate and the source.
10 turns off. Note that a diode 82 and a Zener diode 83 are connected between the gate and the source of the MOS-FET 110, so that when an overvoltage is applied to the gate more than necessary, it can be bypassed. Damage can be prevented.

The overheat detecting circuit 73 is connected to the inverting input terminal of the comparator 85 and the temperature detecting circuit 11 of the semiconductor switch section 54A.
1 and a reference voltage generator 86 is connected to the non-inverting input terminal.

Therefore, in the overheat detecting circuit 73, the MOS-F
As the temperature of the ET 110 increases, the temperature detection circuit 11
As the resistance value of the diode constituting 1 decreases, the potential of the inverting input terminal of the comparator 85 decreases,
When the potential at the inverting input terminal becomes lower than the reference potential, the comparator 85 outputs positive logic. For example, it is set so that a positive logic is output when the temperature of the MOS-FET 110 is 150 ° or more. The logical output of the comparator 85 is sent to the overheat prevention circuit 74 via the inverter 87.

The overheat prevention circuit 74 is roughly divided into a logical value given from the overheat detection circuit 73 and a control signal S1A.
A JK flip-flop 88 that operates on the basis of the JK flip-flop 88, and a MOS-FET 89 that performs on-off operation based on the output of the JK flip-flop 88 to change the gate voltage of the main MOS-FET 110 to control the on / off of the power MOS-FET 110 It consists of.

The power MOS-FET 110 and M
Comparing the capacity with the OS-FET 89, the power MOS
The rated current of the FET 110 is selected to be about 10 [A], while the rated current of the MOS-FET 89 is 10 [A].
[MA], and its circuit area is assumed to be 1 for the power MOS-FET 110.
Is about 1/1000 of that.

The overheat prevention circuit 74 will be specifically described.
The logic output of the overheat detection circuit 73 is input to the clock input CL of the JK flip-flop 88, and the collector of the transistor Tr1 is connected to the reset input R. Here, the control signal S1A is input to the base of the transistor Tr1 via the one-shot multivibrator 90. When the control signal S1A changes from negative logic to positive logic, the output pulse of the one-shot multivibrator 90 is output. Rises, a current flows from the collector of the transistor Tr1 to the emitter. As a result, the potential of the reset input R falls and the JK flip-flop 90 is reset. A regulator 6 is connected to the J input of the JK flip-flop 90.
1 is supplied to the input terminal 101.
, And the K input and the set input S are grounded.

The operation of the JK flip-flop 88 will now be described with reference to FIG. That is, when the control signal S1A becomes positive logic at time t1 (FIG. 3A), the output pulse of the one-shot multivibrator 90 rises and the base potential of the transistor Tr1 rises, so that the reset pulse having a pulse width corresponding to the output panel is generated. (FIG. 3C) is input to the reset input R, and the JK flip-flop 88 is reset.

In this state, at the time t2, the MOS-F
When the temperature of the ET 110 becomes equal to or higher than a predetermined value, the logic output input from the overheat detection circuit 73 to the clock input CL becomes positive logic (FIG. 3B), and as a result, the Q output becomes positive logic. Next, even if the input control signal S1A becomes negative logic at time t3 or the logic output inputted to the clock input CL from the overheat detection circuit 73 becomes negative logic at time t4, JK
The flip-flop 88 keeps this state and keeps outputting positive logic as the Q output. At time t5, the control signal S1A changes from negative logic to positive logic again, and when a reset pulse is input to the reset input R, the Q output is inverted from positive logic to negative logic (FIG. 3 (D)).

As described above, the JK flip-flop 88
When the control signal S1A is in a positive logic state and the output of the overheat detection circuit 73 becomes a positive logic, the Q output of the positive logic is output only when the output of the overheat detection circuit 73 becomes a negative logic. maintain. Here, the overheat prevention circuit 74 has a latch configuration, and once the temperature of the MOS-FET 110 becomes higher than a predetermined temperature, the MOS-FET 110 is turned on until a control signal S1A for turning on the MOS-FET 110 next comes.
Is kept off for the following reasons.

That is, the overheat protection circuit 74 is not latched, and the MOS-FET 1
If you try to control the on / off of 10, MOS-FET
When the temperature of the MOS-FET 110 becomes equal to or higher than the predetermined temperature and the MOS-FET 110 is turned off, the temperature of the MOS-FET 110 falls shortly. When the temperature of the MOS-FET 110 rises again, the MOS
-FET 110 is turned off. When such ON / OFF is repeated many times in a short time, unstable power is supplied to the load 53A. Therefore, the control signal S1A is once set to negative logic and again to positive logic. At first, the MOS-FET 110 is returned to the ON state for the first time.

The Q output of the JK flip-flop 88 is supplied to the gate of the MOS-FET 89 via the buffer 91 which receives the output of the charge pump 62 and shifts the input level by 12 [V] in the same manner as the buffer 81 described above. You. As a result, when the Q output is positive logic (5 [V]), a voltage of 17 [V] is applied to the gate of the MOS-FET 89, so that the MOS-FET 89 is turned on. On the other hand, when the Q output is negative logic (0 [V]), only the ground potential is applied to the gate of the MOS-FET 89, so that the MOS-FET 89 is turned off.

When the MOS-FET 89 is turned on, the gate of the MOS-FET 110 is set to the ground potential. As a result, the MOS-FET 110 is forcibly turned off regardless of the logical output from the AND circuit 72. . On the other hand, when the MOS-FET 89 is turned off, the gate potential of the MOS-FET 110 is
It becomes a value according to the logical output from 2.

Thus, in the overheat detecting circuit 73 and the overheat preventing circuit 74, at least during the period when the temperature of the MOS-FET 110 is equal to or higher than the predetermined value,
Since the switching state of 110 can be forcibly turned off, damage due to overheating of MOS-FET 110 can be avoided.

(3) Manufacturing Method of Switching Device Next, a manufacturing method of the switching device according to the present invention will be described with reference to FIG. First, as shown in FIG.
By sequentially performing oxide film growth processing, drain and source diffusion processing, gate oxide film growth processing, and electrode metal growth processing on a silicon substrate, a large number of power MOS-FETs
A semiconductor wafer 200 having a temperature detection circuit 111 formed adjacent to the semiconductor wafer 110 is formed.

Next, the semiconductor wafer 200 is cut by dicing or scribing to form chip-shaped semiconductor switch portions 54A to 54X. Next, after each of the semiconductor switch units 54A to 54X is packaged, each of the packages 201A to 201X is collectively mounted on one heat radiation fin 202.

As described above, the plurality of semiconductor switch units 54A
To 54X are collectively attached to one radiation fin 202, so that the semiconductor switch units 54A to 54A
The heat generated from the 4X can be collectively processed at one place, and the heat radiation processing can be easily performed. Also, the protection circuits 55A ~
Since heat radiation processing can be performed in a completely different place from that of the protection circuit 55X, conduction of heat to the protection circuits 55A to 55X can be suppressed. All the power MOS-FEs of the semiconductor switch units 54A to 54X
Since it is rare when the T110 is simultaneously turned on, the ratio of the radiation fins 202 to the semiconductor switches 54A to 54X that actually generate heat can be increased, and the radiation efficiency can be increased accordingly.

As shown in FIG. 4B, a semiconductor wafer on which a large number of protection circuits are formed by subjecting a silicon substrate to thin film formation, photoresist formation, exposure, etching, aluminum wiring formation processing, and the like. Create 300. Next, the semiconductor wafer 300 is cut by dicing or scribing to form chip-shaped protection circuits 55A to 55X. Next, the chip-shaped protection circuits 55A to 55X are packaged together in one package 56.

As described above, a large number of chip-like protection circuits 55
A to 55X are packaged together in one package 56, so that a large number of semiconductor chips each having a protection circuit formed thereon can be handled as one unit (one package). It can be simplified and the subsequent work of mounting on the circuit board can be simplified.

Next, as shown in FIG.
The heat radiation fin 202 and the package 56 to which the packages 201A to 201X are mounted are respectively mounted at predetermined positions of 00. Thereby, the packages 201A to 201A
The semiconductor switch units 54A to 54X in 1X and the corresponding protection circuits 55A to 55X in the package 56 are connected by the wiring 401 formed on the circuit board 400.

As described above, in this embodiment, the semiconductor switch units 54A to 54X and the protection circuits 55A to 55X are formed as separate chips, and the semiconductor switch units 54A to 54X having the power MOS-FET 110 are mounted on the same semiconductor wafer 200. By forming the protection circuits 55A to 55X on the same semiconductor wafer 300, the area of each of the semiconductor wafers 200 and 300 can be effectively used, and the production yield of the power MOS-FET and the protection circuit can be reduced. Can be improved.

In the case where a large number of loads having different capacities are provided, such as an automobile, it is necessary to prepare power MOS-FETs having different capacities. In such a case, the same capacity of power M
If the OS-FET is formed on the same semiconductor wafer, the yield can be further improved.

Actually, as described above, the power MOS-FET
Are different in the degree of overcurrent in each power MOS-FET. That is, a power MOS-FET having a larger capacity can flow a larger current.

Therefore, it is necessary to change the configuration of the protection circuit for the power MOS-FET in accordance with the capacity of the power MOS-FET. In this embodiment, however, the protection circuit having the same configuration on the same semiconductor wafer is used. Form a circuit,
After cutting into chips, the volume of the reference voltage generator 77 of the overcurrent detection circuit 71 (FIG. 2) is changed to a power MOS-FET.
Adjust according to the capacity of. This allows each power MOS-F to be connected without lowering the yield when manufacturing the protection circuit.
A protection circuit compatible with ET can be manufactured.

(4) Effect According to the above configuration, the semiconductor switch units 54A to 54X
And protection circuits 55A to 55X that monitor the temperature and current state of the semiconductor switch units 54A to 54X and control the semiconductor switch units 54A to 54X so that the semiconductor switch units 54A to 54X are not damaged by overheating or overcurrent. , Each of which has a separate chip configuration and is housed in a separate package, so that the heat protection circuit 55A for heat generated in the semiconductor switch units 54A to 54X.
To 55X can be suppressed, and as a result, a highly reliable switching device 50 with less malfunction can be realized.

Further, the temperature of the semiconductor switch can be accurately detected by forming the semiconductor switch and the temperature detecting circuit 111 for detecting the temperature of the semiconductor switch on the semiconductor chips constituting the semiconductor switch portions 54A to 54X. Become like As a result, the overheat protection operation by the protection circuit can be made favorable in which the temperature of the semiconductor switch is accurately reflected.

Further, a large number of chip-like protection circuits 55A to 55A
Since the 5Xs are packaged together in one package 56, a large number of semiconductor chips each having a protection circuit formed thereon can be handled as one unit (one package), such as an automobile. In the case where a large number of protection circuits 55A to 55X are required, the handling of the protection circuits 55A to 55X can be simplified, and the work of attaching the protection circuits 55A to 55X to a circuit board can be simplified.

Further, a plurality of semiconductor switch units 54A-5A
4X are collectively attached to one heat radiation fin 202, so that the semiconductor switch units 54A to 54X
The heat generated from the heat can be collectively processed at one place, which facilitates heat radiation processing and increases heat radiation efficiency.

The semiconductor switch units 54A to 54X are formed on the same semiconductor wafer 200, and the protection circuits 55A to 55X are formed on the same semiconductor wafer 300, and the semiconductor wafers 200 and 300 are cut. After the semiconductor switch chip and the protection circuit chip are formed, the chips are connected to each other, so that the production yield can be improved.

(5) Other Embodiments In the above embodiment, the switching device according to the present invention is replaced with a switching device 50 having a configuration as shown in FIG.
And the protection circuit 55A as shown in FIG. 2 has been described as an example, but the present invention is not limited to this, and the point is that a semiconductor switch typified by an intelligent power switch and the semiconductor switch are protected from overcurrent and overheating. The present invention can be widely applied to a switching device having a protection circuit for protection.

In the above embodiment, a plurality of semiconductor switch units 54A to 54X each having a one-chip configuration are provided.
Are separately packaged (so-called single chip packages), and then the packages 201A to 201
Although the case where X is mounted on the radiation fin 202 has been described, the present invention is not limited to this, and a plurality of semiconductor switch units 54A to 54X are collected and packaged together in a package provided with the radiation fin (so-called multi-chip Package).

In this manner, the plurality of semiconductor switch chips can be handled as one unit, as in the case where a plurality of protection circuit chips are housed in one package. The handling and the work of attaching to the circuit board can be simplified.

Similarly, in the above-described embodiment, each of them is 1
A case has been described in which a plurality of protection circuits 55A to 55X having a chip configuration are collected and packaged together in one package 56 (so-called multi-chip package). However, the present invention is not limited to this.
May be separately packaged (so-called single chip package).

Further, in the above-described embodiment, the case where each semiconductor chip is housed in a package and then electrically connected to each other has been described. However, the present invention is not limited to this. You may make it connect electrically.

Further, in the above-described embodiment, a case has been described in which a plurality of semiconductor chips each having a semiconductor switch formed therein are housed in a single package. A semiconductor chip on which a switch is formed may be created, and the semiconductor chip may be housed in a package. In this way, only one semiconductor chip is packaged in one package, and multiple semiconductor switches are packaged in one package, and multiple semiconductor switches are stored in one package. Workability at the time of the operation can be improved.

Similarly, a semiconductor chip in which a plurality of protection circuits are formed in the same chip may be prepared, and this semiconductor chip may be housed in a package.
In this way, only one semiconductor chip is packaged in one package, and multiple protection circuits are packaged in one package.
Workability when a plurality of protection circuits are housed in one package can be improved.

In the above embodiment, the switching device according to the present invention is connected to the junction block 51 of the automobile.
However, the present invention is not limited to this, and can be applied to, for example, a switching device that is connected to a motor of a CD (compact disk) and appropriately supplies power to the motor.

Further, in the above embodiment, the case where the MOS-FET 110 is used as the semiconductor switch has been described. However, the semiconductor switch of the present invention is not limited to this, and the same applies to the case where another semiconductor switch is used. The effect of can be obtained.

[0105]

As described above, according to the first aspect of the present invention, a semiconductor switch which is turned on in response to a control input to a control input terminal and supplies power to a load connected to an output terminal is provided. A protection circuit that protects the semiconductor switch by outputting a signal to a control input terminal to control the semiconductor switch to be off when an overcurrent flows in the semiconductor switch and / or when the semiconductor switch is overheated; In the device, the semiconductor switch and the protection circuit are formed on different semiconductor chips, and the semiconductor chip on which the semiconductor switch is formed and the semiconductor chip on which the protection circuit is formed are housed in separate packages. By doing so, conduction of heat generated from the semiconductor switch to the protection circuit can be suppressed, and as a result, That the malfunction or deterioration can be reduced, it can realize switching apparatus reliability of the switching is improved.

According to the second aspect of the present invention, a plurality of semiconductor chips on which semiconductor switches are formed are housed in a package for housing semiconductor chips on which semiconductor switches are formed, and a protection circuit is provided. The number of units (packages) can be reduced by storing a plurality of semiconductor chips on which a protection circuit is formed in a package for storing the formed semiconductor chips. As a result, the number of units (packages) can be reduced. Easy handling and installation.

According to the third to fifth aspects of the present invention, it is possible to improve the workability when a plurality of semiconductor switches are housed in one package, and to house a plurality of protection circuits in one package. Workability at the time of the operation can be improved.

According to the invention described in claim 6, a plurality of semiconductor switches which are turned on in response to the control input to the control input terminal and supply power to the load connected to the output terminal are provided, and each semiconductor switch is provided. When an overcurrent flows through the switch and / or when the semiconductor switch is overheated, a signal is output to a control input terminal to turn off the semiconductor switch, thereby providing a plurality of protection circuits for protecting the semiconductor switches. In the device, the plurality of semiconductor switches and the plurality of protection circuits are formed on another semiconductor chip, and the one or more semiconductor chips on which the plurality of semiconductor switches are formed are attached to one heat radiation fin. By doing so,
Heat dissipation can be easily performed, and heat conduction to a protection circuit or the like can be suppressed, and heat dissipation efficiency can be increased.

According to the seventh aspect of the present invention, the temperature detecting means for detecting the temperature of the semiconductor switch and providing the detection result to the protection circuit is formed on the semiconductor chip on which the semiconductor switch is formed. In addition, the overheat protection operation by the protection circuit can be made favorable in which the temperature of the semiconductor switch is accurately reflected.

According to the invention, a semiconductor switch having the same configuration and chip area is formed on the same semiconductor wafer, and a protection circuit having the same configuration and chip area is formed on the same semiconductor wafer. Therefore, the area of the semiconductor wafer can be effectively used, and the yield in manufacturing can be improved.

According to the ninth aspect of the present invention, in addition to the effects of the eighth aspect, a switching device capable of further suppressing conduction of heat generated from the semiconductor switch to the protection circuit is manufactured. be able to.

Further, according to the tenth aspect of the present invention,
A protection circuit suitable for each semiconductor switch can be manufactured without lowering the yield when manufacturing the protection circuit.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of a switching device according to the present invention.

FIG. 2 is a circuit connection diagram showing a configuration of a protection circuit.

FIG. 3 is a timing chart for explaining the operation of a JK flip-flop in FIG. 2;

FIG. 4 is a schematic diagram illustrating a method for manufacturing a switching device according to the present invention;

FIG. 5 is a schematic diagram for explaining power supply to each load in an automobile.

FIG. 6 is a schematic diagram for explaining a junction block using a relay having mechanical contacts.

FIG. 7 is a block diagram showing a circuit configuration of a conventional intelligent power switch.

FIG. 8 is a perspective view showing an external configuration of a conventional intelligent power switch.

[Explanation of symbols]

52 Power supply 53A to 53X Load 55A to 55X Protection circuit 56, 201A to 201X Package 57 Radiation fin 110 Semiconductor switch (power MOS-FET) 111 Temperature detection means (Temperature detection circuit) 200, 300 Semiconductor wafer

Claims (11)

[Claims] 1. A semiconductor switch which is turned on in response to a control input to a control input terminal and supplies power to a load connected to an output terminal, and when an overcurrent flows through the semiconductor switch and / or when the semiconductor switch is In a switching device having a protection circuit that protects the semiconductor switch by outputting a signal to the control input terminal to turn off the semiconductor switch when the semiconductor switch is overheated, the semiconductor switch and the protection circuit are separated from each other. A switching device, wherein the semiconductor chip on which the semiconductor switch is formed and the semiconductor chip on which the protection circuit is formed are housed in separate packages. 2. A package for housing a semiconductor chip on which the semiconductor switch is formed contains a plurality of semiconductor chips on which the semiconductor switch is formed and a semiconductor chip on which the protection circuit is formed. 2. The switching device according to claim 1, wherein a plurality of semiconductor chips on which the protection circuit is formed are housed in the package. 3. The switching device according to claim 1, wherein a plurality of the semiconductor switches are formed in the same chip on the semiconductor chip on which the semiconductor switches are formed. 4. The switching device according to claim 1, wherein a plurality of the protection circuits are formed in the same chip on the semiconductor chip on which the protection circuit is formed. 5. The semiconductor chip on which the semiconductor switches are formed, a plurality of the semiconductor switches are formed in the same chip, and the semiconductor chip on which the protection circuit is formed, a plurality of the semiconductor switches are formed in the same chip. 2. The switching device according to claim 1, wherein said protection circuit is formed. A plurality of semiconductor switches that are turned on in response to a control input to a control input terminal to supply power to a load connected to an output terminal, and that an overcurrent flows through each semiconductor switch; and / or A switching device that outputs a signal to the control input terminal to turn off the semiconductor switch when the semiconductor switch is overheated, thereby providing a plurality of protection circuits for protecting the semiconductor switches. A switch and a plurality of the protection circuits are formed on different semiconductor chips, and one or more semiconductor chips on which the plurality of semiconductor switches are formed are attached to one heat radiation fin. And a switching device. 7. The semiconductor chip on which the semiconductor switch is formed is provided with temperature detecting means for detecting the temperature of the semiconductor switch and providing the detection result to the protection circuit. The switching device according to claim 1, 2, 3, 4, 5, or 6. 8. A semiconductor switch that is turned on in response to a control input to a control input terminal to supply power to a load connected to an output terminal, and that an overcurrent flows through the semiconductor switch and / or that the semiconductor switch is A method for producing a switching device having a protection circuit that protects the semiconductor switch by outputting a signal to the control input terminal and turning off the semiconductor switch when overheated; Forming a plurality of semiconductor chips by cutting the semiconductor switches after forming the semiconductor switches; and forming a plurality of semiconductor chips by forming the plurality of protection circuits on a second semiconductor wafer and cutting them. Forming a chip, and attaching the plurality of semiconductor chips on which the semiconductor switches are formed to one radiating fin And a step of electrically connecting said plurality of semiconductor switches and said plurality of protection circuits. 9. A step of accommodating the semiconductor chip on which the semiconductor switch is formed and the semiconductor chip on which the protection circuit is formed in separate packages, respectively; terminals of a package of the semiconductor switch and a package of the protection circuit. 9. The method of manufacturing a switching device according to claim 8, further comprising the step of: electrically connecting the terminal of the switching device. 10. The method for manufacturing a switching device according to claim 8, wherein a volume adjustment for detecting an overcurrent is performed on the semiconductor chip on which the protection circuit is formed. 11. When forming a plurality of said semiconductor switches on said first semiconductor wafer, said semiconductor chips after cutting are provided with a temperature detection means corresponding to said semiconductor switches so as to be provided in said semiconductor chips. 10. The method according to claim 8, wherein the detecting means is formed.
0. The method for manufacturing a switching device according to item 0.