Semiconductor power device with embedded current sensor based on magnetic field

Abstract

The embodiment of the invention relates to a semiconductor power device with a magnetic field-based embedded current sensor. Described is a semiconductor power device having: a package; a power die disposed within the package and integrated with a power structure that generates a load current designed to be supplied to an electrical load. Within the package, the device is also provided with: at least a first conductive path designed to be flowed by a first sense current, the first sense current being a function of the load current; and a current sensor having a magnetic-based operation, integrated into a sensor die coupled to the first conductive path, and generating a current sense signal based on the first sense current and indicative of the load current.

Description

Technical Field

[0001] The present solution relates to a semiconductor power device having a current sensor embedded in a corresponding chip or package for current monitoring based on a magnetic field. Background Art

[0002] As is well known, in electronic devices or systems, especially for analog power applications, it is necessary to monitor the current supplied to a load in order to control and improve the operation of the same electronic device or system.

[0003] For example, known solutions for monitoring current envisage using a resistor connected in series with the load and monitoring the voltage across the same resistor; or using resistors with different areas and different on-resistances RDS. on At least two power devices (eg, MOSFET transistors) connected in parallel and driven with the same signal form a current mirror.

[0004] Other known solutions envisage the use of Hall effect sensors arranged close to a path (for example formed by an electric wire or a conductive track) conveying the current towards the load.

[0005] Although allowing current monitoring, the above-mentioned known solutions have some drawbacks, for example in terms of area occupied or operating frequency limitations, which may be disadvantageous, at least for certain applications. Summary of the Invention

[0006] The present disclosure relates to a semiconductor power device comprising a package and a power die disposed within the package. The integrated power structure is configured to generate a load current (Iload) designed to be supplied to an electrical load. At least a first conductive path is configured to be passed through by a first sensing current (Ir1), wherein the first sensing current is a function of the load current (Iload). A current sensor having magnetic-based operation is integrated into the sensor die coupled to the first conductive path and configured to generate a current sensing signal (Si) based on the first sensing current (Ir1). BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In order that the present disclosure may be better understood, preferred embodiments thereof will now be described, by way of non-limiting example only, and with reference to the accompanying drawings, in which:

[0008] Figure 1 shows a schematic plan view of an electronic power device according to an embodiment of the present solution;

[0009] Figure 2A It is taken along line AA Figure 1 A schematic cross section of a device;

[0010] Figure 2B It is taken along line BB Figure 1 A schematic cross section of a device;

[0011] Figure 2C It is taken along line CC Figure 1 A schematic cross section of a device;

[0012] Figure 3 Shown Figure 1 A schematic cross-section of a possible implementation of a power die in a device of FIG. 1 ; and

[0013] Figure 4 Shown Figure 1 Schematic circuit block diagram of the device. DETAILED DESCRIPTION

[0014] As used herein, the terms "contacting," "connecting," and "coupling" are intended to have the broadest possible meaning. For example, the phrase "A is connected to B" should be understood to encompass a direct connection between A and B, where there are no intervening components or elements, as well as an indirect connection, where there are one or more intervening components or elements between A and B. Similarly, the term "coupled" should be interpreted in the same manner, such that "A is coupled to B" includes both direct physical or electrical coupling and indirect coupling through one or more intervening components or elements. Unless expressly stated otherwise, these terms do not require direct physical contact.

[0015] As will be described below, one aspect of the present solution contemplates providing a semiconductor power device having a current sensor with magnetic-based operation embedded or integrated within a corresponding container or package for monitoring the current flowing through the same device to supply a load.

[0016] As will be described in detail, at least one specific electrical path is defined within the package of a semiconductor power device and is designed to sense a current that is a function of a load current supplied to an electrical load. A magnetic sensor within the package is arranged to sense a magnetic field generated by the sense current flowing along the specific electrical path and provide a sense signal indicative of the sense current (and therefore, based on a ratiometric ratio, the load current).

[0017] In detail and with reference Figure 1 and Figures 2A to 2C In a possible embodiment shown in a corresponding cross section of FIG, a semiconductor power device (indicated as a whole by 1) is formed in an integrated manner as a chip and includes a package 2.

[0018] In the example, the package 2 is of the so-called QFN (Quad Flat No Lead) type having a substantially parallelepiped shape; however, it is emphasized that other types of packages (and other shapes) are likewise conceivable.

[0019] The package 2 comprises an outer coating 4 of epoxy or other type of material (eg ceramic material) which defines an interface with respect to the external environment and which surrounds and incorporates therein structural elements that are part of the power device 1 .

[0020] In particular, the external coating 4 defines at least a portion of the upper external surface 2a and the lateral external surface 2b and the corresponding lower external surface 2c of the package 2. The aforementioned upper external surface 2a and lower external surface 2c have their main extension in a horizontal plane xy and are opposite each other relative to a vertical axis z orthogonal to the horizontal plane xy, along which the thickness of the package 2 is defined.

[0021] The package 2 further comprises leads or electrical contact terminals 5 made of an electrically conductive material (e.g. copper), possibly coated with a thin layer of nickel, arranged externally relative to the coating 4 and accessible from the outside (e.g. flush with the same coating 4), in particular at a lateral outer surface 2 b of the package 2 and at a lower outer surface 2 c of the same package 2, intended to be coupled to a printed circuit board (PCB) of an external electronic system in which the power device 1 is used. During operation, an electrical load supplied by the load current flowing and generated in the power device 1 may also be coupled to the same printed circuit board.

[0022] In the illustrated embodiment, the electrical contact terminals 5 are arranged in two parallel rows on opposite sides (along the horizontal axis y) of the lateral outer surface 2b of the package 2. In particular, in the example, the number of electrical contact terminals 5 in each row is nine (thus indicated by progressive numbers from 1 to 9 for the first row and from 10 to 18 for the second row), aligned along a horizontal axis x, which forms a horizontal plane xy with the horizontal axis y.

[0023] The package 2 internally comprises a support element or frame 6 (often called a "lead frame") made of an electrically conductive material (e.g., copper) at least partially incorporated within the coating 4. In particular, the support element 6 defines an island (or pad), in the example shown, having a generally rectangular shape, having its main extension in the horizontal plane xy, and having a lower surface that contributes to defining the aforementioned lower outer surface 2c of the package 2.

[0024] The power device 1 further comprises a power die 10 of semiconductor material, which is carried on a corresponding upper surface (opposite to the lower surface) within the package 2 and by a support element 6, and has an integrated power structure configured to generate the load current. In one embodiment, the integrated power structure is a MOSFET (metal oxide semiconductor field effect transistor) type.

[0025] In a known manner, the integrated power structure comprises a plurality of active cells contributing to providing the aforementioned load current at at least one corresponding current conducting terminal (eg between a drain terminal and a source terminal in the case of a MOSFET structure).

[0026] For illustrative (and non-limiting) purposes, with reference to a MOSFET structure, Figure 3 A schematic cross section of a possible implementation of an integrated power structure in a power die 10 and corresponding active cells (here indicated by 11 ) is shown.

[0027] In this implementation, the power die 10 includes a substrate 12 of doped semiconductor material, such as N + Doped silicon (or, alternatively, other materials such as, for example, silicon carbide, SiC). The substrate 12 has a first surface 12a and a second surface 12b opposite each other along a vertical axis z, which is orthogonal to the aforementioned horizontal plane xy.

[0028] Doped semiconductor material (eg, N - The structural layer 14 is for example epitaxially grown on the substrate 12 and is delimited at the top by an upper surface 14a (opposite to the above-mentioned first surface 12a along the vertical axis z).

[0029] The structure layer 14 accommodates a body region 16 at the active region 2, which in this example is P-doped and extends deep into the structure layer 14 starting from the upper surface 14a. In this example N + A doped source region 18 is arranged within the body region 16 , facing the upper surface 14 a of the structural layer 14 .

[0030] The power die 10 further includes gate regions 20, in this example trench gate regions, formed in corresponding trenches extending from the upper surface 14 a toward the substrate 12 into the structural layer 14. Each gate region 20 includes an outer insulating portion 20 a (e.g., silicon oxide) and an inner conductive portion 20 b (e.g., polysilicon), which are arranged relative to each other in such a manner that the conductive portion 20 b is insulated from the structural layer 4 by the insulating portion 20 a.

[0031] The power die 10 further comprises, at the active area, a conductive layer, in particular a source metallization 24, formed of a conductive layer (e.g., a metal layer), extending over the upper surface 14a of the structural layer 14, in direct contact with the source regions 18 to allow them to be biased during operation (thus forming a source contact terminal, i.e., the first current-conducting terminal of the MOSFET structure). The source metallization 24 has a planar extension that substantially corresponds to the extension of the active area in the horizontal plane xy.

[0032] The source metallization 24 contacts the source region 18 via a plurality of contact elements 25, which extend into corresponding contact openings formed by an insulating layer 26 (e.g., silicon oxide), which covers the upper surface 14a of the structural layer 14 (in particular, insulates the source metallization 24 from a conductive portion 20b of the gate region 20, which faces the same upper surface 14a as the structural layer 14).

[0033] By means not illustrated here, suitable connection elements are also envisaged above the upper surface 14 a of the structural layer 14 for the electrical connection of the gate region 20 and for the definition of the gate contact terminal of the MOSFET structure.

[0034] A further electrically conductive layer 27 forming the drain contact terminal (ie the second current conducting terminal of the MOSFET structure) extends over the second surface 12 b of the substrate 12 , in direct electrical contact with the same substrate 12 .

[0035] In particular and again with reference to the above Figure 1 and Figures 2A to 2C As illustrated in the corresponding cross section of FIG, the conductive layer 27 is in direct electrical contact with the support element 6 of the power device 1.

[0036] According to one aspect of the present solution and as the same Figure 1 and Figures 2A to 2C As shown in the above cross section of FIG, the source metallization 24 arranged on top of the power die 10 includes a main portion 24a, whose extension (e.g., a rectangle or square in the horizontal plane xy) is located above most of the active area and is in contact with most of the above-mentioned source region 18 of the active cell 11 of the MOSFET transistor. For example, the extension of this main portion 24a is comprised between 50% and 80% of the extension of the above-mentioned active area.

[0037] Furthermore, the same source metallization 24 comprises at least a first conductive strip 24 b, which is separate and distinct from the aforementioned main portion 24 a and, in the example, extends along the horizontal axis y. In particular, this first conductive strip 24 b is arranged at a peripheral portion of the aforementioned active area, transversely relative to the main portion 24 a, above at least one aforementioned source region 18 of a respective one of the active cells 11 (in electrical contact with the same first conductive strip 24 a).

[0038] The source metallization 24 also preferably comprises a second conductive strip 24c, separate and distinct with respect to the above-mentioned main portion 24a and the first conductive strip 24b, extending in the example along the horizontal axis y, parallel to the same first conductive strip 24b.

[0039] In particular, the second conductive strip 24c is inserted between the first conductive strip 24b and the main portion 24a along the horizontal axis x, and there is a certain spacing distance between the first conductive strip 24b and the second conductive strip 24c and between the same second conductive strip 24c and the main portion 24a along the same horizontal axis x.

[0040] like Figure 1 as well as Figure 2B As shown in the cross section of FIG, the power device 1 further comprises a current sensor 30 with magnetic-based operation, in particular a magnetometer, more particularly based on the magnetoresistance principle. The current sensor 30 may be an AMR (Anisotropic Magnetoresistance) sensor; alternatively, the current sensor 30 may be a TMR (Tunnel Magnetoresistance) or GMR (Giant Magnetoresistance) sensor.

[0041] The current sensor 30 is formed in a sensor die 31, for example made of a semiconductor material such as silicon, which integrates a suitable magnetic field sensing structure, for example of the capacitive type and based on the Lorentz force (of a known type, not described in detail here). In a possible implementation, this sensing structure is a MEMS (micro-electromechanical system) structure.

[0042] According to one aspect of the present solution, the sensor die 31 is arranged on and in contact with the first conductive strip 24 b and, in the example shown, also on and in contact with the second conductive strip 24 c. The sensor die 31 has a rectangular or square shape in the horizontal plane xy and, in particular, has an extension along the horizontal axis x that is greater than the sum of the respective extensions of the first conductive strip 24 b and the second conductive strip 24 c and the corresponding separation distance along the same horizontal axis x.

[0043] Furthermore, the power device 1 comprises a contact element 34 made of an electrically conductive material, for example copper, which is arranged above the aforementioned source metallization 24 .

[0044] In particular, the contact element 34 is configured and shaped so as to electrically connect the first and second conductive strips 24b, 24c to the main portion 24a of the source metallization 24 such that they are at the same potential (corresponding to the potential of the source terminal).

[0045] In detail, this contact element 34 comprises a main portion 34 a having a rectangular or square extension in the horizontal plane xy, arranged on the main portion 24 a of the source metallization 24 and in contact therewith, thereby defining throughout its entire extension a homogenous electrical contact with respect to the majority of the active cells 11 in which the power structure is integrated.

[0046] The contact element 34 further includes a first bridging portion 34b (eg Figure 2A ), which in the example comprises a cantilever extension along the horizontal axis x, starting from the main portion 34a of the same contact element 34, towards the first conductive strip 24b (thus extending at a certain distance along the vertical axis z above the second conductive strip 24c); and a first connecting portion 36 (at Figure 1 It is schematically shown in Figure 2A ), which extends vertically along the vertical axis z from the above-mentioned first bridging portion 34b (in particular from a distal end thereof relative to the main portion 34a) until the end of the above-mentioned first conductive strip 24b and contacts the end in a local manner.

[0047] In particular, the first connecting portion 36 has a substantially square (or circular) cross section in the horizontal plane xy, and its extension in the same horizontal plane xy is much smaller than the extension of the above-mentioned first conductive strip 24b (this cross section is also contained in the same first conductive strip 24b).

[0048] The contact element 34 further includes a second bridging portion 34c (eg Figure 2C ), also having a cantilever extension along the horizontal axis x, starting from the main portion 34a of the same conductive element 34, above the first conductive strip 24b (at a certain distance apart along the vertical axis z) and the second conductive strip 24c; and a second connecting portion 37 (at a certain distance apart along the vertical axis z) Figure 1 It is schematically shown in Figure 2C (shown in FIG. 3 ), it extends vertically along the vertical axis z from the second bridging portion 34c (particularly, starting from its central portion) to the respective ends of the second conductive strip 24c and partially contacts the respective ends (particularly, arranged on the opposite side along the y-axis relative to the aforementioned ends of the first conductive strip 24b). Furthermore, the first connecting portion 36 and the second connecting portion 37 are staggered or offset along the horizontal axis x and are arranged at the first conductive strip 24b and the second conductive strip 24c, respectively.

[0049] from Figure 1 It is evident that the aforementioned bridge portions 34 b , 34 c define a window 38 therebetween in the horizontal plane xy, in particular along the horizontal axis y; the aforementioned current sensor 30 is arranged at and within this window 38 .

[0050] like Figure 1 As shown schematically, the above-mentioned contact element 34 electrically contacts the electrical contact terminals 5 of one of the two parallel rows (in the example the first row and the corresponding terminals indicated by reference numerals 1 to 9), which together define the source terminals of the MOSFET structure of the external electronic system (short-circuited to each other).

[0051] like Figure 1 and Figure 2C As shown in the cross section of FIG. 1 , in the same layer defining the above-mentioned source metallization 24 , a gate contact pad 40 is also formed, which contacts the gate region 20 of the active cell 11 of the MOSFET transistor in a manner not shown in detail.

[0052] In addition, if Figure 1 as well as Figure 2B and Figure 2C As shown in the cross-section, the power device 1 includes a circuit die 42 of semiconductor material (e.g., silicon) integrating an ASIC (application-specific integrated circuit) electronic circuit, which is operably and electrically coupled to the power die 10 (in the example, coupled to the corresponding MOSFET transistor) and the sensor die 31.

[0053] In particular, the circuit die 42 is arranged on the main portion 34 a of the contact element 34 (centered with respect to the horizontal plane xy in the example), coupled thereto by a thin layer of insulating material 43 , for example a non-conductive double-sided adhesive material.

[0054] In detail, as mentioned above Figure 1 and Figure 2B As shown schematically, first bonding wires 44 electrically connect the circuit die 42 (particularly corresponding contact pads carried by an upper surface opposite to the surface for bonding to the contact elements 34) to the sensor die 31 (particularly corresponding contact pads carried by a corresponding upper surface opposite to the surface for bonding to the first and second conductive strips 24c). In the illustrated embodiment, the first bonding wires 44 are partially arranged within the window 38.

[0055] In addition, if Figure 2C As shown, at least a second bond wire 45 electrically connects the circuit die 42 to the gate contact pad 40 .

[0056] like Figure 1As shown, in the example of the second of the two parallel rows (in particular, in the example, the terminals are indicated by reference numerals 16 to 18), a third bonding wire 46 electrically connects the circuit die 42 to corresponding electrical contact terminals 5, which define the input / output terminals of the power device 1 relative to the external electronic system.

[0057] As previously mentioned, the various elements forming the power device 1 (particularly including the power die 10, the source metallization 24, the sensor die 31, the contact element 34, the circuit die 42, and the first bonding wire 44, the second bonding wire 45 and the third bonding wire 46) are encapsulated within the outer coating 4 of the package 2.

[0058] In more detail and also refer to Figure 4 The circuit diagram of the ASIC electronic circuit integrated into the circuit die 42 includes a driver stage 50, which is operatively coupled to the power die 10 and configured to provide a drive signal S to the gate region 20 of the power structure integrated into the same power die 10 through the gate contact pad 40. d The driver stage 50 is also connected to at least one of the above-mentioned input / output terminals of the electrical contact terminal 5 and is in particular adapted to generate the above-mentioned driver signal S d The function receives the gate bias signal V from the external electronic system g .

[0059] The same ASIC electronic circuit also includes a sensing stage 52 that is operatively coupled to the sensor die 31 of the current sensor 30 and is configured to provide a suitable bias signal to the magnetic field sensing structure integrated into the sensor die 31 and also to receive at least the current sensing signal S from the same sensing structure. i The sensing stage 52 is also connected to at least one of the above-mentioned input / output terminals of the electrical contact terminal 5 and in particular provides an output signal S indicative of the sensing current (and therefore of the load current). out .

[0060] In the example of the MOSFET transistor mentioned earlier, Figure 4 An equivalent circuit diagram of the power structure integrated into the power die 10 is also shown.

[0061] In particular, transistor M1 represents at least one active cell 11 of a MOSFET transistor coupled to the first conductive strip 24b, the drain of transistor M1 being connected to a power supply terminal (defined by a drain contact terminal) and receiving a power supply voltage V al , and the gate terminal is connected to the above-mentioned driver stage 50 to receive the drive signal S d .

[0062] Similarly, transistor M2 represents at least one corresponding and different active cell 11 of a MOSFET transistor coupled to the second conductive strip 24c, with its drain connected to the power supply terminal and its gate connected to the aforementioned driver stage 50 to receive the drive signal S d .

[0063] Transistor M3 represents the parallel connection of the remaining majority of the active cell 11 of the power device 1 arranged at the main portion 24a of the source metallization, with the drain of transistor M3 being connected to the power supply terminal and the gate terminal being connected to the aforementioned driver stage 50 to receive the same drive signal S d , and the source terminal is connected to the source contact terminal.

[0064] In the same Figure 4 , the first current path and the second current path defined by the first conductive strip 24b and the second conductive strip 24c are also schematically represented, wherein the current sensor 30 is formed in the corresponding sensor tube core 31, which is arranged at the same first conductive strip 24b and the second conductive strip 24c.

[0065] During operation of the power device 1, the above-mentioned active cell 11 of the power structure is configured to generate a load current, here denoted by I, after appropriate electrical biasing of the driver stage 50. load Indicates that the load current is supplied to the external electronic component acting as a load.

[0066] In the power die 10, this load current I load From the conductive layer 27 forming the drain contact terminal flows to the source metallization 24 which is uniformly contacted by the contact element 34 defining the source contact terminal.

[0067] In addition, within the same power die 10, at least one path is defined for the first sensing current, here represented by I r1 Indicates that in at least one active cell 11 of the MOSFET transistor (represented by the transistor M1 above), the first sense current flows from the conductive layer 27 (ie, from the drain contact terminal) to the first conductive strip 24b and then along Figure 1 and Figure 4 A first direction of the y-axis indicated by a corresponding arrow in FIG. 2 flows through the first bridge portion 34 b of the contact element 34 toward the source contact terminal.

[0068] Thus, according to a proportional ratio substantially defined by the area ratio (in the horizontal plane xy) between the first conductive strip 24b and the main portion 24a of the source metallization 24 (this ratio is for example comprised in the range between 10% and 25%), the first sensing current I r1helps to generate the above-mentioned load current I as part of it load .

[0069] In addition, the first sensing current I r1 Generates magnetic flux that can be sensed by the current sensor 30 to generate the above-mentioned current sensing signal S i .

[0070] As previously discussed, within the same power die 10, a second sensing current (herein represented by I r2 In at least one corresponding active cell 11 of the MOSFET transistor (represented by the transistor M2 above), the second sense current flows from the conductive layer 27 (ie, from the drain contact terminal) to the second conductive strip 24c, and then along Figure 1 and Figure 4 The second direction of the y-axis indicated by the corresponding arrow in FIG (relative to the first sensing current I r1 The first direction of the current is opposite to that of the first direction of the current.

[0071] Thus, according to a proportional ratio (e.g. within the same range indicated previously) substantially defined by the area ratio between the second conductive strip 24c and the main portion 24a of the source metallization 24 (in the horizontal plane xy), the second sense current I r2 It also helps to generate the above-mentioned load current I load .

[0072] The second sensing current I r2 Generates a corresponding magnetic flux sensed by the current sensor 30, which helps to generate the current sensing signal S i .

[0073] Advantageously, the sensing stage 52 integrated into the circuit die 42 can be based on the first sensing current I having the opposite direction. r1 and the second sensing current I r2 The generated magnetic flux realizes a differential sensing scheme in order to generate an output signal S out The contribution due to any external magnetic field or interference is eliminated.

[0074] The advantages of the proposed solution are apparent from the foregoing disclosure.

[0075] Regardless, it is emphasized that this solution allows measuring and / or monitoring current in analog power applications over a very wide frequency range, from direct current (DC) to several MHz.

[0076] Furthermore, the described solution allows the manufacture of current sensors integrated into semiconductor power devices in an extremely small volume within the package of an integrated system, with a much lower area occupation compared to conventional measurement solutions (using discrete components external and separate to the semiconductor power device, such as resistors, transistors or Hall effect sensors).

[0077] In a similar manner, the present solution allows the manufacture of semiconductor power devices with integrated functionality for monitoring current, in particular the current supplied to a corresponding load.

[0078] Finally, it will be apparent that modifications and variations may be made to what has been described and illustrated herein without departing from the scope of the present disclosure, as defined in the appended claims.

[0079] In particular, it is emphasized that within the package 2 of the power device 1 , the arrangement of the sensing current path (defined by the first and second conductive strips 24 b and 24 c ) may be different, for example, it can be aligned parallel to the horizontal axis x.

[0080] Furthermore, it is emphasized that the ASIC electronic circuitry integrated into circuit die 42 may have other functionalities besides monitoring current and driving the integrated power structure.

[0081] A semiconductor power device (1) can be summarized as comprising: a package (2); a power die (10) arranged in the package (2) and integrating a power structure configured to generate a load current (I load ), the load current (I load ) is designed to supply an electric load, characterized in that it includes in the package (2): at least a first conductive path (24b) configured to be supplied by a first sensing current (I r1 ) flows through, the first sensing current (I r1 ) is the load current (I load ) function; and a current sensor (30) having a magnetic-based operation, integrated into a sensor die (31) coupled to the first conductive path (24b), and configured to sense the first current (I r1 ) to generate the current sensing signal (S i ).

[0082] The package (2) may include at least one input / output electrical contact terminal (5) relative to an external environment; and may also include a circuit die (42) integrating electronic circuitry within the package (2), which may include a sensing stage (52) operatively coupled to the current sensor (30) and configured to receive the current sensing signal (S i), and outputting an indication load current (I load ) output signal (S out ).

[0083] The package (2) may have at least one further input / output electrical contact terminal (5) relative to the external environment; and the electronic circuit integrated into the circuit die (42) may further include a driver stage (50) operatively coupled to a power structure in the power die (10) and configured to provide a bias signal (V g ) to provide a driving signal (S d ).

[0084] The device may further comprise, within the package (2), a second conductive path (24c), arranged parallel to the first conductive path (24b) and parallel to the extension axis (y), and designed to be sensed by a second sensing current (I r2 ) relative to the first sensing current (I r1 ) flows in the opposite direction along the extension axis (y), and the second sensing current (I r2 ) is the load current (I load ) function; wherein the current sensor (30) can also be coupled to the second conductive path (24c) for further sensing the current (I r2 ) of the current sensing signal (S i ) is generated.

[0085] The device may comprise within a package (2): a conductive layer (24) arranged above the power die (10) and configured to define current conducting terminals of the power structure, the conductive layer (24) may comprise a main portion (24a) and at least a first conductive strip (24b), the first conductive strip (24b) being separate and distinct from the main portion (24a) and defining the first conductive path; and furthermore, a contact element (34) of conductive material, arranged above the conductive layer (24) and configured to electrically connect the first conductive strip (24b) to the main portion (24a) so that they are at the same electrical potential.

[0086] The package (2) may have at least one electrical contact terminal (5), the load current (I load ) is present at at least one electrical contact terminal (5); wherein the contact element (34) can be electrically coupled to the at least one electrical contact terminal (5).

[0087] The sensor die (31) may be arranged on and in contact with the first conductive strip (24b).

[0088] The contact element (34) may include: a main portion (34a) having a main extension in a horizontal plane (xy) and being arranged on and in contact with the main portion (24a) of the conductive layer (24), defining uniform electrical contact throughout the main extension of the main portion; and a first bridging portion (34b) having a cantilever extension from the main portion (34a) above the power tube core (10) and provided with a first connecting portion (36), the first connecting portion (36) extending vertically from the far end of the first bridging portion (34b) relative to the main portion (34a) to the horizontal plane (xy), contacting the first end of the first conductive strip (24b) in a local manner.

[0089] The first conductive strip (24b) may have a main extension along an extension axis (y) of the horizontal plane (xy), and the first sensing current (I r1 ) can be designed to flow along the first conductive strip (24b) in a first direction of the extension axis (y) from the second end of the first conductive strip (24b) toward the first end, and flow into the contact element (34) through the first connecting portion (36) and the first bridging portion (34b), the second end being opposite to the first end relative to the extension axis (y).

[0090] The conductive layer (24) may further include: a second conductive strip (24c) separated and distinct from the main portion (24a) and the first conductive strip (24b), defining a second conductive path arranged parallel to the first conductive path and parallel to the extension axis (y), and designed to allow a second sensing current (I r2 ) in relation to the first sensing current (I r1 ) flows in a second direction opposite to the first direction along the extension axis (y), and the second sensing current (I r2 ) is the load current (I load ) function; and the contact element (34) may include a second bridging portion (34c) having a cantilever extension from the main portion (34a) above the power tube core (10) and provided with a second connecting portion (37), the second connecting portion (37) extending vertically from the second bridging portion (34b) to the horizontal plane (xy) to locally contact the corresponding first end of the second conductive strip (24c), the corresponding first end being opposite to the first end of the first conductive strip (24b) relative to the extension axis (y).

[0091] The second sensing current (I r2 ) can be designed to flow in the second direction from the corresponding second end of the second conductive strip (24c) along the second conductive strip (24c) toward the corresponding first end, and flow into the contact element (34) through the second connecting portion (37) and the second bridging portion (34c), the corresponding second end being opposite to the corresponding first end relative to the extension axis (y).

[0092] The first and second bridge portions (34b, 34c) may define a window (38) between the first and second bridge portions along the extension axis (y), in which the sensor die (31) of the current sensor (30) is arranged.

[0093] The device may further comprise a circuit die (42) with integrated electronic circuitry within the package (2), which may comprise a sensing stage (52) operably coupled to the current sensor (30); wherein the circuit die (42) may be arranged above the main portion (34a) of the contact element (34) and may be electrically connected to the sensor die (31) of the current sensor (30) by a bonding wire (44).

[0094] The power structure integrated into the power die (10) may define a power transistor, and the conductive layer (24) may define a first current conduction terminal of the power transistor; the power structure may further include an additional conductive layer (27) at a surface of the power die (10) opposite to the surface for bonding to the conductive layer (24) along the vertical axis (z), the additional conductive layer (27) may define a second current conduction terminal of the power transistor; wherein the load current (I load ) may be designed to flow between the second current conducting terminal and the first current conducting terminal.

[0095] The power transistor may be of MOSFET type and may comprise a plurality of cells (11) each having a corresponding source region (18); and: the source region (18) of at least one of the cells (11) may be electrically coupled to the first conductive strip (24b); and the source regions (18) of the remaining cells (11) may be electrically coupled to the main portion (24a) of the conductive layer (24), which may be the source metallization of the power transistor.

[0096] The current sensor (30) may include a magnetometer based on the magnetoresistive principle.

[0097] The various embodiments described above can be combined to provide further embodiments. These and other changes can be made to the embodiments in light of the detailed description above. Generally, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in this specification and the claims, but should be construed to encompass all possible embodiments and the full scope of equivalents to which such claims are entitled. Therefore, the claims are not limited by this disclosure.

Claims

1. A semiconductor power device, comprising: Package; a power die disposed within the package and integrating a power structure configured to generate a load current configured to be supplied to an electrical load, The package comprises: at least a first conductive path configured to pass a first sense current, wherein the first sense current is a function of the load current; as well as A current sensor is integrated into a sensor die coupled to the first conductive path and configured to generate a current sensing signal based on the first sensing current.

2. The device of claim 1 , further comprising a circuit die having integrated electronic circuitry within the package, the circuit die comprising a sensing stage operatively coupled to the current sensor; wherein the package has at least one input / output electrical contact terminal relative to the external environment; and The sensing stage is configured to receive the current sensing signal and output an output signal indicative of the load current on the at least one input / output terminal of the package.

3. The device according to claim 2, wherein the package has at least one further input / output electrical contact terminal relative to the external environment; wherein the electronic circuit integrated into the circuit die further comprises a driver stage operatively coupled to the power structure in the power die; and The driver stage is configured to provide a drive signal to the integrated power structure based on a bias signal at the at least one further input / output terminal of the package.

4. The device according to claim 1, further comprising within the package: a second conductive path arranged parallel to the first conductive path and parallel to the extension axis and configured to be passed through by a second sensing current in an opposite direction along the extension axis relative to a corresponding direction of the first sensing current, the second sensing current being a function of the load current; wherein the current sensor is further coupled to the second conductive path for generating the current sensing signal; and The current sensing signal is further based on the second sensing current.

5. The device according to claim 1, comprising within the package: a conductive layer disposed over the power die and configured to define current conducting terminals for the power structure; as well as a contact element of conductive material disposed above the conductive layer; wherein the conductive layer comprises a main portion and at least a first conductive strip, the first conductive strip being separate and distinct from the main portion and defining the first conductive path; and The contact element is configured to electrically connect the first conductive strip to the main portion, and to place both the first conductive strip and the main portion at the same electrical potential.

6. The device of claim 5, wherein the package has at least one electrical contact terminal, the load current being present at the at least one electrical contact terminal; and Wherein the contact element is electrically coupled to the at least one electrical contact terminal. 7 . The device of claim 5 , wherein the sensor die is disposed on and in contact with the first conductive strip.

8. The device of claim 5, wherein the contact element comprises: a main portion having a main extension in a horizontal plane and arranged on and in contact with said main portion of said conductive layer, said main extension defining a uniform electrical contact throughout said main portion; as well as A first bridging portion has a cantilever extension from the main portion above the power tube core and is provided with a first connecting portion, which extends vertically from the far end of the first bridging portion relative to the main portion to the horizontal plane to locally contact the first end of the first conductive strip.

9. The device according to claim 8, wherein the first conductive strip has a main extension along an extension axis of the horizontal plane, and the first sensing current is configured to flow along the first conductive strip in a first direction of the extension axis from a second end portion of the first conductive strip toward the first end portion, and to flow into the contact element through the first connecting portion and the first bridging portion, the second end portion being opposite to the first end portion with respect to the extension axis.

10. The device according to claim 9, wherein the conductive layer further comprises: a second conductive strip, separate and distinct from the main portion and the first conductive strip, and defining a second conductive path arranged parallel to the first conductive path and parallel to the axis of extension, and configured to pass a second sense current in a second direction along the axis of extension opposite to the first direction of the first sense current, the second sense current being a function of the load current; and The contact element includes a second bridging portion having a cantilever extension from the main portion above the power tube core and is provided with a second connecting portion, the second connecting portion extending vertically from the second bridging portion to the horizontal plane and locally contacting the corresponding first end of the second conductive strip, the corresponding first end being opposite to the first end of the first conductive strip relative to the extension axis.

11. The device according to claim 10 , wherein the second sensing current is configured to flow in the second direction from the corresponding second end of the second conductive strip along the second conductive strip toward the corresponding first end, and to flow into the contact element through the second connecting portion and the second bridging portion, the corresponding second end being opposite to the corresponding first end with respect to the extension axis. 12 . The device of claim 10 , wherein the first bridge portion and the second bridge portion define a window between the first bridge portion and the second bridge portion along the extension axis, in which the sensor die of the current sensor is disposed.

13. The device according to claim 5 further includes a circuit die integrating an electronic circuit within the package, wherein the electronic circuit includes a sensing stage operably coupled to the current sensor; wherein the circuit die is arranged above the main portion of the contact element and is electrically connected to the sensor die of the current sensor by a bonding wire.

14. A device according to claim 5, wherein the power structure integrated into the power tube core defines a power transistor, and the conductive layer defines a first current conduction terminal of the power transistor; at a surface of the power tube core opposite to the surface for bonding to the conductive layer along the vertical axis, the power structure also includes an additional conductive layer, and the additional conductive layer defines a second current conduction terminal of the power transistor; wherein the load current is configured to flow between the second current conduction terminal and the first current conduction terminal.

15. The device of claim 14, wherein the power transistor is of MOSFET type and comprises a plurality of cells each having a corresponding source region; and wherein: a source region of at least one of the cells being electrically coupled to the first conductive strip; And the source regions of the remaining ones of the cells are electrically coupled to the main portion of the conductive layer, which is the source metallization of the power transistor.

16. The device of claim 1, wherein the current sensor comprises a magnetometer based on the magnetoresistive principle.

17. A semiconductor package, comprising: A power die integrating a power structure configured to generate a load current that is supplied to an electrical load, at least a first conductive path configured to pass a first sensing current, the first sensing current being a function of the load current; sensor die; A current sensor is integrated into the sensor die coupled to the first conductive path, the current sensor being configured to generate a current sensing signal based on the first sensing current.

18. The semiconductor package according to claim 17, further comprising: a second conductive path disposed adjacent to the first conductive path and the extension axis and configured to cause a second sensing current to flow in an opposite direction along the extension axis relative to a corresponding direction of the first sensing current, the second sensing current being a function of the load current; wherein the current sensor is further coupled to the second conductive path for generating the current sensing signal; and The current sensing signal is based on the second sensing current.

19. The semiconductor package according to claim 17, further comprising: a circuit die having integrated electronic circuitry, the circuit die including a sensing stage operatively coupled to the current sensor; as well as at least one input / output electrical contact terminal relative to the external environment; The sensing stage is configured to receive the current sensing signal and output an output signal indicative of the load current on the at least one input / output terminal of the package.

20. The semiconductor package according to claim 19, further comprising: at least one further input / output electrical contact terminal relative to the external environment; wherein the electronic circuit integrated into the circuit die further comprises a driver stage operatively coupled to the power structure in the power die; and The driver stage is configured to provide a drive signal to the integrated power structure based on a bias signal at the at least one further input / output terminal of the package.

Images