TW201723447A - Semiconductor component comprising a substrate and a first temperature measuring element, and method for determining a current flowing through a semiconductor component, and control unit for a vehicle - Google Patents

Abstract

A semiconductor component (10) comprising a substrate and at least two temperature measuring elements (20, 22) is described. The two temperature measuring elements (20, 22) are arranged on the bare die (11) of the semiconductor component (10) at different positions within the semiconductor component (10). In particular, one temperature measuring element (20) can be arranged in an active region (14) and one temperature measuring element (22) in a passive region (16) of the semiconductor component (10). The temperature measuring elements (20, 22) measure two different temperatures TJ, Tsense, with the aid of which the current IDS through the semiconductor component (10) can then be calculated. The semiconductor component can be a power MOSFET (18). Furthermore, a method for determining a current IDS flowing through a semiconductor component (10) is described, wherein two temperatures measured at different locations of the semiconductor component (10) are used. The semiconductor component (10) described and the method described are suitable for example for use in a control unit for a vehicle.

Description

Semiconductor component including a substrate and a first temperature measuring component, and method for measuring current flowing through a semiconductor component, and control unit for vehicle

The present invention relates to a semiconductor component, preferably a power MOSFET component; and to a method of producing a semiconductor component and a control unit for a vehicle.

Modern semiconductor switches (eg, power MOSFETs (metal-oxide-semiconductor field effect transistors) and IGBTs (insulated gate bipolar transistors) require, in addition to ultra-low on-state and switching losses and high barrier capabilities, More and more integrated forming functions, through which functions can reliably detect overload (eg, ESD (electrostatic discharge) pulses), over temperature, crash, or over current. In power electronics systems, for example, for engine control, the phase current used for regulation of the system is very important. Excessive high currents during the switching process can cause the component to collapse and can cause damage to the component. Therefore, in many cases, for example, the current is measured via a shunt or a magnetic sensor. This practice is both complicated and expensive. If the phase current is measured by a shunt, then an additional area is required on the DBC (direct solder copper) or on the lead frame to achieve this. Furthermore, the use of the shunt or magnetic sensor also requires the use of another component, which also incurs costs.

Alternatively, the measurement of the phase current inside the device can also be performed by separate cell regions. However, in this case, at least one external resistor and an external estimation circuit (often analogous) are required.

DE 10 2011 001 185 A1 describes a method for current sensing by measuring the drain-source voltage. In this case, the temperature of the depletion layer is measured and the temperature dependent resistance value R _DSon is calculated from this temperature, and then the current current can be calculated from R _DSon .

US 2007/00061099 A1 likewise describes a method for determining the phase current by means of the drain-source voltage and a temperature. A thermistor arranged adjacent to a FET (field effect transistor) provides a temperature from which the processor can predict the phase current from the temperature and the drain-source voltage. This is done assuming that the temperature difference between the thermistor and the depletion layer of the FET is constant in the steady state state.

US 2011/0210711 A1 describes a possible way of simulating the processing in a semiconductor component by means of a processor in order to be able to carry out an evaluation of the state of the component and, therefore, if appropriate, to control the component. To achieve this, for example, the temperature supplied by a thermistor, the drain-source voltage, and the gate-source voltage are used as input parameters.

The present invention provides a semiconductor member including a substrate and a first temperature measuring element, wherein the first temperature measuring element is arranged near a position in the semiconductor member having high power loss, and wherein a second temperature The measuring element is spatially arranged on the substrate at a distance from the first temperature measuring element. For example, the semiconductor component can be a MOSFET, an IGBT, or a specific other power semiconductor. The substrate can be half guided The bulk substrate, for example, a germanium substrate, a specific other semiconductor substrate, or a silicon-on-insulator (SOI) substrate.

In this case, a position having a high power loss is understood to mean that a high power loss in the semiconductor wafer during operation (specifically, in a state of being switched to be turned on) is lowered and the temperature is thus heated up to be greater than The location of the surrounding environment. In this case, specifically, "high power loss" should be interpreted on the basis of other locations in the wafer. Preferably, the first temperature measuring component is arranged near the location of the highest power loss, for example, in the vicinity of the depletion zone. Preferably, the position between the position having high power loss or the highest power loss and the distance between the first temperature measuring elements is as small as possible, specifically, the smaller the technology, the better, without affecting the uniqueness. The function of the component. In other words, the first temperature measuring component is preferably located in close proximity to a location with high power loss or highest power loss. For example, the first temperature measuring component can directly abut the depletion region of the semiconductor component.

The method for determining the current flowing through a semiconductor component according to the invention comprises, in principle, the following steps: a) reading out the first temperature supplied by the first temperature measuring element arranged in the region having high power loss a value; b) reading a value of a second temperature supplied by a second temperature measuring element, the second temperature measuring element being located at a distance from the first temperature measuring element; and c) utilizing the first temperature And the second temperature is used to calculate the current through the semiconductor component.

The control unit for a vehicle according to the invention comprises at least one semiconductor component according to the invention.

The advantage of the semiconductor component according to the invention is that only a few additional components are required The current current flowing through the semiconductor component can be stated very accurately. For the purposes of this estimation, only the logic of the system ASIC (application-specific integrated circuit) and the AD converter may be used, so the present invention requires only a few compared to conventional semiconductor components without current sensing according to the present invention. Additional components.

Furthermore, with the semiconductor component according to the invention and the method according to the invention, the phase current flowing through the component can be determined without the need to include the drain-source voltage as an initial value.

Instead, the individual zone temperatures are measured at two different points of the semiconductor component, and the thermal resistance and thermal capacitance between the two measurement points are known, so that the current power loss of the component can be inferred. , 俾 enables the current flowing through the component to be determined by means of the resistance value R _DSon . Thus, overcurrent limiting of safe switching of power electronic components (eg, MOSFETs or IGBTs) can be established.

The first temperature measuring component is thermally coupled to the second temperature measuring component. It is assumed in a particular embodiment that the first temperature measuring element and the second temperature measuring element comprise a diode in each case. The temperature measurement in each of the cases herein may be the voltage that falls across the individual diodes. In this way, the temperature can be measured in the temperature measuring elements with a low structural cost. Therefore, the structural space, power loss, and cost for the external members can be saved, and the response time and accuracy of the current monitoring can be improved with an appropriate design.

According to a preferred embodiment of the invention, it is assumed that the first temperature measuring element and the second temperature measuring element are integrated into the semiconductor component in an integrally formed manner. This measure can reduce the cost when the semiconductor component is built, which also reduces the effective cost. this The measure requires only a small number of unique components. Since these necessary functions can be integrated into known semiconductor components with little cost, in general, this leads to significant cost saving effects. Again, the significance of a smaller number of unique components is that there are fewer possible sources of failure.

In one of the developments of the invention, the semiconductor component includes a third temperature measuring component. Similarly, there may be an additional fourth temperature measuring component or even more temperature measuring components. The accuracy of the current measurement can be improved by incorporating additional temperature measuring elements. The additional temperature measuring elements can also be integrated into the wafer in an integrally formed manner. For example, all temperature measuring elements can be implemented as a planar polysilicon diode; however, in principle, any combination of different temperature measuring elements may be employed to carry out the invention. Likewise, it is also possible to use both integrally formed integrated temperature measuring elements as well as external temperature measuring elements, such as thermistors. However, in view of the advantages of production engineering, preferably, all of the temperature measuring elements are integrated in an integrally formed manner.

In another preferred embodiment of the invention, a finite thermal capacitance and a finite thermal resistance are present between the first temperature measuring component and the second temperature measuring component. If the first temperature and the second temperature are utilized as calculated input variables, then the current power loss of the semiconductor component can be determined in a relatively accurate manner.

In one development of the invention, the semiconductor component has at least one active region and at least one passive region, wherein the second temperature measuring component is arranged in the passive region. The temperature in the passive zone is often lower than the temperature in the active zone and, in particular, will be significantly lower than the temperature in the zone with the highest power loss. The large temperature difference between the two temperatures measured by the first temperature measuring element and the second temperature measuring element increases the signal to noise ratio and thus the accuracy of the measured value of the current.

In one preferred embodiment of the invention, the semiconductor component can be a MOSFET, and one of the temperature measuring components can be the body diode of the MOSFET. A MOSFET is particularly suitable for embodiments of a power semiconductor component, for example, an embodiment of a power switch. If the body diode of the MOSFET is used as one of the temperature measuring elements, then the number of additional components required to perform the present invention is reduced because the body diode is inherently present In every MOSFET.

It is assumed in one of the advantageous developments of the invention that the first temperature measurement voltage across the first temperature measuring element and/or across the second temperature measuring element can be tapped in each case via a dedicated contact pad. The second temperature measures the voltage. In other words, the position point among the circuits related to measuring the two temperature measurement voltages can be externally contacted. The advantage of this configuration is that such a configuration can be further interconnected from the outside in a flexible manner. Furthermore, the voltage required to determine the temperature can thus be measured in a simple manner, for example by means of a contact pad connected to an evaluation circuit, for example the system ASIC.

In a particular embodiment, the first temperature measuring component and the second temperature measuring component are connected in series. The two temperature measuring components are then fed into a common current source and the same current flows through the temperature measuring components. Further temperature measuring elements that may be present are also capable of interconnecting the first temperature measuring elements and the second temperature measuring elements in series and being powered by a single sensing current.

Alternatively, the first temperature measuring element and the second temperature measuring element may also be connected in parallel.

Particularly fast and precise diodes will facilitate the implementation of the invention, the diodes The forward voltage profile is ideally very well matched to temperature. The relatively low thermal resistance and thermal capacitance between the hot spot (that is, the location of the wafer with high power loss or highest power loss) and the particular edge of the wafer or other location within the passive region can result in very good The signal-to-noise ratio is minimal due to the temperature profile among the other layers that are manipulated by changes such as flux, shrinkage, DBC (direct solder copper), or adhesives.

The method according to the invention is suitable for determining the current temperature, power loss, and current values of a power switch and determining the adjustment variables in order to avoid accelerated aging or damage of the component.

Advantageous developments of the invention are detailed in the patent dependents and are described in the description.

2‧‧‧Main field effect transistor (FET)

3‧‧‧Source contact

4‧‧‧汲pole contacts

5‧‧‧gate contacts

6‧‧‧Measure field effect transistor (FET)

7‧‧‧Resistors

8‧‧‧ Current measurement point

10‧‧‧Semiconductor components

11‧‧‧Orange die

12‧‧‧Substrate

14‧‧‧active area

16‧‧‧ Passive zone

18‧‧‧Edge area

20‧‧‧First temperature measuring element

22‧‧‧Second temperature measuring element

24‧‧‧ Body diode

26‧‧‧First current source

27‧‧‧second current source

30‧‧‧ source

32‧‧‧汲polar

34‧‧‧ gate

40 ‧ ‧ layer

42‧‧‧ layer

44‧‧‧ layer

46‧‧‧ layer

50‧‧‧ first node

52‧‧‧second node

54‧‧‧Power loss source

58‧‧‧ Thermal Capacitor

60‧‧‧Thermal resistance

70‧‧‧Special Application Integrated Circuit (ASIC)

72‧‧‧Computational components

74‧‧‧Computational components

76‧‧‧Differential Module

78‧‧‧ Lookup Table

Exemplary embodiments of the present invention will now be explained in more detail with reference to the drawings and the following description. In the drawings: Figure 1 shows a possible way of measuring the current flowing through a semiconductor component according to the prior art, and Figure 2 is a schematic view of one exemplary embodiment of a semiconductor component according to the present invention, 3 is a plan view of an exemplary embodiment of the present invention according to FIG. 2, and FIG. 4 is a side view of an exemplary embodiment of the present invention according to FIG. 2, and FIG. 5 is a view according to the present invention. A first embodiment of a circuit system interconnection of a semiconductor component, and a second embodiment of the circuit system interconnection of a semiconductor component according to the present invention, Figure 7 is a third embodiment of a circuit system interconnection of a semiconductor component in accordance with the present invention, and Figure 8 is a thermal equivalent circuit diagram of one embodiment of a semiconductor component in accordance with the present invention, Figure 9 Shown is a diagram of exemplary measurement results, and a diagram of one of the possible ways in which a semiconductor component in accordance with the present invention is integrated into a circuit system.

First, the possible mode of measuring the current flowing through a semiconductor component 10 in accordance with the prior art is shown in the form of a current sensor having a plurality of discrete cell bodies. The main FET (Field Effect Transistor) 2 is shown on the right hand side of the figure. Its source contact 3, drain contact 4, and gate contact 5 are interconnected in a conventional manner. The measurement FET 6 is illustrated in the left hand region of the figure. It is connected in parallel to the main FET 2 and is composed of a plurality of cell bodies which are separated from the cell body of the main FET 2 but are identical. The separate cell bodies act as a current mirror. By means of the external resistor 7, a current I _Sense can be read out at the current measuring point 8, which current can directly infer the current flowing through the main FET 2. However, the resistor 7 limits the dynamic range and accuracy of the current measurement. Furthermore, in the solutions known in the prior art, a temperature sensor and a current sensor are often used in combination in order to achieve the purpose of monitoring, which in turn leads to a relatively high structural and control engineering cost.

2 schematically shows a die 11 of a semiconductor component 10 in the form of a power switch, for example, a MOSFET. The semiconductor component 10 includes: an active region 14, that is, an area where the possibly very small switching elements are placed, and There is an electrical power loss in the middle; and a passive zone 16, which has no effect and, therefore, no power loss. For example, the passive zones 16 can be solder pad regions, edge regions of the component 10, or gate runners. The second current measuring component 22 is arranged in each of the passive regions 16.

Figure 3 is a plan view of the semiconductor component of Figure 2. Two temperature measuring elements 20, 22 are arranged on the bare die 11. Such so-called temperature measuring structures are positioned such that the first temperature measuring element 20 is arranged in the active zone 14 or at least very close to the active zone 14. The second temperature measuring element 22 is located at a particular spatial distance from the first temperature measuring element, for example, in the edge region 18 of the member. The power loss in the active region 14 is higher than in the passive region 16. Preferably, the first temperature measuring element 20 can be arranged in the vicinity of the depletion region of the semiconductor component 10 because the power loss is particularly high. The present invention contemplates that there is a large temperature difference between the temperature measured by the first temperature measuring component 20 and the temperature measured by the second temperature measuring component 22 to improve the signal to noise ratio.

Figure 4 is a transverse cross-sectional view of the exemplary embodiment of Figures 2 and 3. The substrate 12 can be distinguished from the substrate, and the additional structures are integrated into the substrate. Furthermore, the figure also shows that the structure consists of a plurality of layers 40, 42, 44, and 46.

The temperature measuring elements 20, 22 can be electrically connected in various ways. The first possible way for interconnecting the semiconductor component 10 in accordance with the present invention is shown in FIG. Known terminals of source 30, drain 32, and gate 34 can be distinguished from the figure. The first diode 20 serving as the first temperature measuring element and the second diode 22 serving as the second temperature measuring element are connected in series. A constant current I _sense will flow through the two diodes 20, 22, which can be provided by the ASIC 70, for example. The voltage drops U _D1 and U _D2 are proportional to the temperature of the individual regions of the first diode 20 and the second diode 22, respectively.

A second possible way of interconnecting the semiconductor component 10 in accordance with the present invention is shown in FIG. In this case, the first diode 20 and the second diode 22 are connected in parallel. In this case, they are fed by a first current source 26 and a second current source 27.

The body diode 24 of the power MOSFET 18 is used as the second diode in the embodiment shown in FIG. 7 for temperature measurement.

Figure 8 is a thermal equivalent circuit diagram of one embodiment of the present invention in the form of an equivalent Foster network. The thermal behavior of one of the embodiments of the MOSFET on the DBC (direct solder copper) or on the lead frame in the present invention can be described in this manner. The first temperature measuring element in the form of a first diode 20 measures the temperature T _J at the first node 50. Here, T _J represents T _junction , that is, it is the temperature in the region of the depletion layer (which often corresponds to the region of the semiconductor member 10 having the highest power loss). Conversely, the second diode 22 measures the temperature T _Tsense at the second node 52. The finite thermal resistance 60 and the thermal capacitance 58 may occur between the two nodes 50, 52 due to the different spatial arrangement of the power loss sources 54 in the wafer. In the normal case, this leads to a temperature T _Tsense below the temperature T _J . The right hand side of the figure illustrates the terminal of the network at room temperature T _ambient .

Since the two temperatures T _J and T _{Tsense are known} , the temperature difference ΔT between the two nodes 50, 52 can be determined. For example, the series of measurements performed by the present invention are shown in FIG. The thermal resistance between the nodes 50, 52 and the housing in each case is determined in this figure. The data point depicted as a circular symbol begins with the measured value _Zth (t) _{Junction-Case} , that is, it is the time dependent thermal resistance between the first node 50 and the housing. Correspondingly, the value of _Zth (t)T _sense-Case is depicted as a square, that is, it is the thermal resistance between the second node 52 and the housing.

The third curve is the difference between the first two measurement curves, which is depicted as a triangular symbol. The solid line shows the corresponding fit of the Foster model for each of the seven RC elements of the two measurement curves and the two RC elements for the difference curve. The curve description in the Foster model can be used to achieve simulation results of temporal thermal behavior in the ASIC.

As can be seen from the figure, in the steady state, that is, after about 50 ms to 100 ms, the interpolation curve advances substantially horizontally, that is, between the two thermal resistance values Z _th (t) _Junction- The difference between _Case and Z _th (t)T _sense-Case is actually kept constant. By ΔT and the current time constant ΔZ _th =Z _th (t) _{Junction-Case} -Z _th (t)T _sense-Case , then, the current power among the crystal grains can be calculated according to the following formula loss.

Because, for example, the resistance R _DSon of the component in switching to conduction and steady state can be calculated using the following formula:

Where α~0.4, which can be used to determine the current current based on the following formula. For example, all of the calculations mentioned above can be implemented in any ASIC that may be present.

A schematic diagram of one of the possible configurations of this ASIC is shown in Figure 10. The ASIC 70 first provides a constant current I _sense for the two current measuring components 20, 22. In the computing elements 72, 74, first, the two forward voltage signals U _D1 , U _{D2 of the} temperature measuring elements 20, 22 (which are also in the form of diodes) are then converted into temperature values T. _Sense , T _J . To this end, a corresponding characteristic curve linearization will be performed in advance if appropriate.

To determine the temperature difference, a difference ΔT is then formed in the differential module 76. Since the temperature T _{J is known} , the current resistance R _on (T _J ) can then be predicted by the above-mentioned formula (2). Furthermore, the thermal behavior of the thermal differential resistance Z _thJ -T _sense has been previously measured and permanently stored in the ASIC by measurement or simulation, for example, stored as a two-element Foster network or stored as a Form 78. This is very accurate because the value of _ZthJ- T _sense is only _inferred from the components that are arranged on the wafer in a fixed manner, and therefore, it is expected that there should be no variation due to construction and joining techniques. Next, the current _threshold current I _ds can be determined from the input variables ΔT(t), R _on (T _J ), and Z _thJ -T _sense by the formula proposed above, and serves as the control of the power switch and / or monitor variables. For example, the temperature T _J (t) can also serve as another control and/or monitoring variable.

In particular, the invention can be used in a control unit for a vehicle, for example, to drive a vehicle. The invention can equally be used in power modules for hybrid vehicles or electric vehicles as well as in "self-locking" MOSFETs. Similarly, many further applications for power MOSFETs and IGBTs can be devised.

10‧‧‧Semiconductor components

11‧‧‧Orange die

14‧‧‧active area

16‧‧‧ Passive zone

18‧‧‧Edge area

20‧‧‧First temperature measuring component

22‧‧‧Second temperature measuring element

Claims (10)

A semiconductor component (10) comprising a substrate (12) and a first temperature measuring component (20), wherein the first temperature measuring component (20) is arranged in the semiconductor component (10) Near the location of the high power loss, and characterized in that a second temperature measuring component (22) is spatially arranged on the substrate (12) at a distance from the first temperature measuring component (20). The semiconductor component (10) of claim 1, wherein each of the first temperature measuring component (20) and the second temperature measuring component (22) comprises a diode. The semiconductor component (10) according to any one of the preceding claims, wherein the first temperature measuring component (20) and the second temperature measuring component (22) are integrated into the semiconductor component in an integrally formed manner. Among them. A semiconductor component (10) according to any one of the preceding claims, wherein a finite thermal capacitance (58) and a finite thermal resistance (60) are present in the first temperature measuring component (20) and the second temperature measurement Between components (22). The semiconductor component (10) according to any one of the preceding claims, wherein the semiconductor component (10) has at least one active region (14) and at least one passive region (16), wherein the second temperature measuring component ( 22) is arranged in the passive zone (16). The semiconductor component (10) according to any one of the preceding claims, wherein the semiconductor component (10) is a MOSFET, and wherein one of the temperature measuring components (20, 22) is the MOSFET Body diode (24). The semiconductor component (10) according to any one of the preceding claims, wherein the first temperature measurement voltage (U _D1 ) across the first temperature measuring component (20) is tapped through respective dedicated touch pads and/or A second temperature measurement voltage (U _D2 ) across the second temperature measuring element (22) is possible. The semiconductor component (10) according to any of the preceding claims, wherein the first temperature measuring component (20) and the second temperature measuring component (22) are connected in series. A method for determining a current flowing through a semiconductor component (10), comprising the steps of: a) reading out a first temperature measuring component (20) arranged in a region having a high power loss a value of the first temperature (T _J ); b) reading a value of a second temperature (T _sense ) provided by a second temperature measuring element (22), the second temperature measuring element (22) being spatially located a distance from the first temperature measuring component (20); and c) using the first temperature (T _J ) and the second temperature (T _sense ) to calculate a current flowing through the semiconductor component (10). A control unit for a carrier, comprising at least one semiconductor component (10) according to any one of claims 1 to 8.