Semiconductor module with external power sensor and manufacturing process for it and a cooling system comprising these

Abstract

A semiconductor module, comprising: a semiconductor chip; a potting compound that encases the semiconductor chip; a plurality of terminals electrically connected to the semiconductor chip and protruding from the potting compound, wherein a first of the terminals has a constricted region covered by the potting compound, the potting compound having a recess or opening near the constricted region of the first terminal; and a coreless magnetic field sensor arranged in the recess or opening of the potting compound and insulated from the first terminal by the potting compound, wherein the coreless magnetic sensor is configured to generate a signal in response to a magnetic field generated by a current flowing in the constricted region of the first terminal, the magnitude of the signal being proportional to the current flowing in the constricted region of the first terminal.

Description

BACKGROUND

[0001] Accurate operation of inverter enclosures or modules requires AC current measurement to ensure effective system performance. AC current measurement is typically implemented using core-based magnetic sensors. Core-based open-loop current sensors are limited in their performance, primarily due to the adverse effects of the iron core. For example, core-based open-loop current sensors suffer from hysteresis, saturation, nonlinearity, temperature-dependent permeability, eddy current effects, and other issues. Some of these problems can be mitigated by an external circuit to compensate for the magnetic flux generated by the test current and a probe to determine zero flux in the air gap. However, the additional circuitry, the compensation winding, and the additional power dissipation in the compensation winding significantly increase the overall cost of the measurement system implementation.

[0002] In most cases, the intrinsic accuracy of core-based sensors is insufficient to meet end-user requirements, for example, in traction inverters for motor vehicles. Therefore, end-of-line calibration may be necessary to compensate for sensor gain and offset errors. This calibration step is expensive because high currents must be forced with high accuracy after the inverter module and current sensor are mounted. Since the calibration step is typically performed only at room temperature, the residual error remains significant due to lifetime drift and temperature dependence, impacting overall system performance. US 2013 / 0058143A1 discloses power semiconductor modules with semiconductor chips encapsulated, a variety of terminals protruding from the encapsulation, and a current sensor, which may be a Hall effect sensor.Further power semiconductor modules are disclosed in US 2016 / 0 014 916 A1.

[0003] Therefore, there is a need for an improved external power sensor for semiconductor modules. SUMMARY

[0004] According to one embodiment of a semiconductor module, the semiconductor module consists of: a semiconductor chip; a potting compound encasing the semiconductor chip; a plurality of terminals electrically connected to the semiconductor chip and protruding from the potting compound, wherein a first of the terminals has a constricted region covered by the potting compound, the potting compound having a recess or opening near the constricted region of the first terminal;and a coreless magnetic field sensor arranged in the recess or opening of the potting compound and insulated from the first terminal by the potting compound, wherein the coreless magnetic sensor is configured to generate a signal in response to a magnetic field generated by a current flowing in the constricted region of the first terminal, the magnitude of the signal being proportional to the amount of current flowing in the constricted region of the first terminal.

[0005] The coreless magnetic field sensor can be a magnetoresistive sensor or a Hall sensor.

[0006] Individually or in combination, the narrowed area of ​​the first terminal can include a tapered area over which the width of the first terminal tapers; the potting compound recess can be located near the tapered area of ​​the first terminal; the coreless magnetic field sensor can be an asymmetric sensor arranged in the potting compound recess and comprise a single sensor element located next to one side of the tapered area; and the single sensor element can be isolated from the tapered area by the potting compound.

[0007] Individually or in combination, the narrowed area of ​​the first terminal can include a tapered area over which the width of the first terminal tapers; the potting compound recess can be located near the tapered area of ​​the first terminal; the coreless magnetic field sensor can be a differential sensor arranged in the potting compound recess and comprise a first sensor element positioned next to a first side of the tapered area, and a second sensor element positioned next to a second side of the tapered area opposite the first side; and the first and second sensor elements can be isolated from the tapered area by the potting compound.

[0008] Individually or in combination, the narrowed area of ​​the first terminal can include a coiled area, the potting compound recess can be located near the coiled area of ​​the first terminal, the coreless magnetic field sensor being an asymmetric sensor located in the potting compound recess and comprising a single sensor element located next to one side of the coiled area, and the single sensor element being isolated from the coiled area by the potting compound.

[0009] Individually or in combination, the narrowed area of ​​the first terminal can include a coiled area, the potting compound recess can be located near the coiled area of ​​the first terminal, the coreless magnetic field sensor can be a differential sensor located in the potting compound recess and comprise a first sensor element located adjacent to a first side of the coiled area and a second sensor element located adjacent to a second side of the coiled area opposite the first side, and the first and second sensor elements can be isolated from the coiled area by the potting compound.

[0010] Individually or in combination, the narrowed area of ​​the first terminal can include an area of ​​the first terminal with an opening, the opening of the potting compound can be aligned with the opening in the first terminal, the coreless magnetic field sensor can be an asymmetric sensor arranged in the opening of the potting compound and comprise a single sensor element arranged above or below the opening in the first terminal, and the single sensor element can be insulated from a side wall of the opening in the first terminal by the potting compound.

[0011] Individually or in combination, the narrowed area of ​​the first terminal can include an area of ​​the first terminal with an opening; the opening of the potting compound can be aligned with the opening in the first terminal; the coreless magnetic field sensor can be a differential sensor arranged in the opening of the potting compound and comprise a first sensor element arranged above the opening in the first terminal and a second sensor element arranged below the opening in the first terminal; and the first and second sensor elements can be insulated from a side wall of the opening in the first terminal by the potting compound.

[0012] Individually or in combination, the potting compound may have a projection that covers more of the first connection than of any of the other connections that protrude from the same side of the potting compound as the first connection, and the recess or opening of the potting compound may be formed in the projection.

[0013] The semiconductor chip can be a power semiconductor chip, either individually or in combination; the semiconductor module can have double-sided cooling; and the first connection can be an AC output connection of the power semiconductor chip.

[0014] According to one embodiment of a cooling system, the cooling system comprises: a plurality of individual semiconductor modules, each containing a semiconductor chip; a potting compound encasing the semiconductor chip; a plurality of terminals electrically connected to the semiconductor chip and protruding from the potting compound, wherein a first of the terminals has a constricted region covered by the potting compound, the potting compound having a recess or opening near the constricted region of the first terminal;and a coreless magnetic field sensor arranged in the recess or opening of the potting compound and insulated from the first terminal by the potting compound, the coreless magnetic field sensor being configured to generate a signal in response to a magnetic field generated by a current flowing in the constricted region of the first terminal, the magnitude of the signal being proportional to the strength of the current flowing in the constricted region of the first terminal; and a first cover connected to a second cover to form a sealed housing containing the plurality of individual semiconductor modules and a cavity between the covers and the individual semiconductor modules for a fluid flow through a plurality of openings formed in the first and / or second cover.

[0015] Each coreless magnetic field sensor in the cooling system can be a magnetoresistive sensor or a Hall sensor.

[0016] Individually or in combination, the narrowed area of ​​each first terminal can include a tapered area over which the width of the first terminal tapers; the potting compound recess can be located near the tapered area of ​​the first terminal; the coreless magnetic field sensor can be an asymmetric sensor arranged in the potting compound recess and comprise a single sensor element located next to one side of the tapered area; and the single sensor element can be isolated from the tapered area by the potting compound.

[0017] Individually or in combination, the narrowed area of ​​each first terminal can include a tapered area over which the width of the first terminal tapers; the potting compound recess can be near the tapered area of ​​the first terminal; the coreless magnetic field sensor can be a differential sensor arranged in the potting compound recess and comprise a first sensor element located adjacent to a first side of the tapered area and a second sensor element located adjacent to a second side of the tapered area opposite the first side; and the first and second sensor elements can be isolated from the tapered area by the potting compound.

[0018] Individually or in combination, the narrowed area of ​​each first terminal can include a coiled area, the potting compound recess can be near the coiled area of ​​the first terminal, the coreless magnetic field sensor can be an asymmetric sensor located in the potting compound recess and include a single sensor element located next to one side of the coiled area, and the single sensor element can be isolated from the coiled area by the potting compound.

[0019] Individually or in combination, the narrowed area of ​​each first terminal can include a coiled area; the potting compound recess can be located near the coiled area of ​​the first terminal; the coreless magnetic field sensor can be a differential sensor arranged in the potting compound recess and comprise a first sensor element positioned adjacent to a first side of the coiled area and a second sensor element positioned adjacent to a second side of the coiled area opposite the first side; and the first and second sensor elements can be isolated from the coiled area by the potting compound.

[0020] Individually or in combination, the narrowed area of ​​each first terminal can include an area of ​​the first terminal with an opening, the opening of the potting compound can be aligned with the opening in the first terminal, the coreless magnetic field sensor can be an asymmetric sensor arranged in the opening of the potting compound and comprise a single sensor element located above or below the opening in the first terminal, and the single sensor element can be insulated from a side wall of the opening in the first terminal by the potting compound.

[0021] Individually or in combination, the constricted area of ​​each first terminal can include an area of ​​the first terminal with an opening; the opening of the potting compound can be aligned with the opening in the first terminal; the coreless magnetic field sensor can be a differential sensor arranged in the opening of the potting compound and comprise a first sensor element arranged above the opening in the first terminal and a second sensor element arranged below the opening in the first terminal; and the first and second sensor elements can be insulated from a side wall of the opening in the first terminal by the potting compound.

[0022] Individually or in combination, the potting compound of each individual semiconductor module may have a projection that covers more of the first terminal than of any of the other terminals that protrude from the same side of the potting compound as the first terminal, and the recess or opening of the potting compound may be formed in the projection.

[0023] Individually or in combination, each semiconductor chip can be a power semiconductor chip, with each individual semiconductor module having double-sided cooling and each first terminal being an AC output terminal of the power semiconductor chip.

[0024] According to one embodiment of a method for manufacturing a semiconductor module, the method comprises: electrically connecting a plurality of terminals to a semiconductor chip; potting the plurality of terminals and the semiconductor chip such that the semiconductor chip is enclosed in a potting compound and the plurality of terminals protrudes from the potting compound, wherein a first of the terminals has a constricted region which is covered by the potting compound, wherein the potting compound has a recess or an opening in the vicinity of the constricted region of the first terminal;and placing a coreless magnetic field sensor in the recess or opening of the potting compound, wherein the coreless magnetic field sensor is isolated from the first terminal by the potting compound and is configured to generate a signal in response to a magnetic field generated by a current flowing in the constricted region of the first terminal, wherein the magnitude of the signal is proportional to the strength of the current flowing in the constricted region of the first terminal.

[0025] The expert will recognize additional features and benefits when he reads the following detailed description and considers the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The elements in the drawings are not necessarily to scale. Identical reference numbers denote corresponding similar parts. The features of the various illustrated embodiments can be combined, provided they are not mutually exclusive. Embodiments are shown in the drawings and are described in detail in the following description. Fig. Figure 1 shows a perspective view of an embodiment of a semiconductor module with a coreless magnetic field sensor. Fig. Figure 2 shows a flowchart of an embodiment of a process for producing the in Fig. 1 semiconductor module shown. Fig. Figure 3A shows an enlarged view of a section of the semiconductor module. Fig. 1, before the coreless magnetic field sensor is positioned in a recess of the potting compound. Fig. Figure 3B shows the same view of the semiconductor module as in Fig. 3A, however, after the coreless magnetic field sensor was placed in the recess. Fig. 3C shows a partial cross-section of the semiconductor module along the in Fig. 1 line labelled AA'. Fig. Figure 4 shows a top view of the embodiment of a connection of the semiconductor module made of Fig. 1 with a narrowed area in the immediate vicinity of the coreless magnetic field sensor. Fig. Figure 5 shows a top view of another embodiment of a connection of the semiconductor module made of Fig. 1 with a narrowed area in the immediate vicinity of the coreless magnetic field sensor. Fig. Figure 6 shows a perspective view of another embodiment of a semiconductor module with a coreless magnetic field sensor. Fig. Figure 7A shows an enlarged view of a section of the semiconductor module. Fig. 6, before the coreless magnetic field sensor is positioned in an opening in the potting compound. Fig. Figure 7B shows the same view of the semiconductor module as in Fig. 7A, however, after the coreless magnetic field sensor was placed in the recess. Fig. Figure 7C shows a partial cross-section of the semiconductor module along the line labeled BB' in Fig. 6. Fig. Figure 7D shows a top view of an embodiment of a connector of the semiconductor module made of Fig. 6 with an opening for receiving the coreless magnetic field sensor. Fig. Figure 8 shows a perspective view of an embodiment of a cooling system with several individual semiconductor modules, each with an integrated, coreless magnetic field sensor. DETAILED DESCRIPTION

[0027] The embodiments described here integrate a coreless, open-loop current sensor into the housing of a power module. A terminal of the power module has a sensor structure that generates a magnetic field for current measurement, and the housing's encapsulation is designed to allow the coreless current sensor to be mounted and aligned with the sensor structure. Since the coreless sensor lacks an iron core, the corresponding negative effects (e.g., temperature dependence, hysteresis, etc.) are eliminated. To suppress extreme stray fields, the design can be implemented as a differential measurement concept. For a differential design, the coreless current sensor can be oriented relative to the busbar in several ways. Both lateral and vertical integration of the sensor are described here. Alternatively, the sensor implementation can be asymmetrical, for example, in low-noise applications.The module's encapsulated body is configured to accommodate the coreless magnetic field sensor, with the current sensor positioned either above, below, or within the terminal. The encapsulated module body can also be configured to isolate the current sensor from the terminal being monitored.

[0028] Fig. Figure 1 shows an embodiment of a semiconductor module 100 with an integrated, coreless, open-loop current sensor 102. The semiconductor module 100 contains one or more semiconductor chips 104, 106, such as a power MOSFET (metal-oxide-semiconductor field-effect transistor), HEMT (high electron mobility transistor), IGBT (insulated-gate bipolar transistor), JFET (junction FET), or similar devices. In one embodiment, the semiconductor chip(s) 104, 106 are SiC chips that do not have internal current-sensing capability. The one or more semiconductor chips 104, 106 are encapsulated with a potting compound 108 and are therefore in Fig. 1 not visible and represented by corresponding dashed boxes.

[0029] The semiconductor module 100 also includes a plurality of terminals 110, 112, 114, which are electrically connected to one or more semiconductor chips 104, 106 and protrude from the potting compound 108. The terminals 110, 112, 114 can be electrically connected to the semiconductor chip(s) 104, 106, for example, by bond wires, metal strips, metal clips, etc. In one embodiment, the terminals 110, 112, 114 are leads of a leadframe. In another embodiment, at least the power terminals 110, 114 are busbars or tabs. Other types of terminals can also be used. Different types of terminals can be used in the same module. For example, leadframe terminals can be used for the control and / or sensor connections, and busbar or flat-pin terminals can be used for the power connections. The number and type of the provided connections 110, 112, 114 depend on the type of semiconductor module.

[0030] In the case of a half-bridge power semiconductor module, for example, a high-side semiconductor chip 104 and a low-side semiconductor chip 106 are encapsulated with potting compound 108. A first group of terminals 112 of the semiconductor module 100 can be control and sampling terminals to supply control signals to the high-side and low-side semiconductor chips 104 and 106 and to receive telemetry data from the module 100, such as current sampling information, temperature sampling information, etc. The high-side and low-side semiconductor chips 104 and 106 can be SiC chips that do not have internal current sensing capabilities. A second group of terminals 110 are DC supply terminals for providing positive and negative (or ground) potentials to the high-side and low-side semiconductor chips 104 and 106. The high-side and low-side semiconductor chips 104 and 106 are electrically connected in series at a common output node.Another terminal 114 is an AC output terminal which is electrically connected to the common output node of the semiconductor chips 104, 106.

[0031] The AC output terminal 114 has a constricted area that is covered by the potting compound 108. The constricted area is in Fig. 1 not visible.

[0032] The coreless magnetic field sensor 102 integrated into the semiconductor module 100 is configured to generate a signal in response to a magnetic field induced by the current flow in the constricted area of ​​the module 100's AC output terminal 114. The coreless magnetic field sensor 102 has one or more connections 116, such as pins, leads, etc., for accessing the signal generated by the sensor 102. The coreless magnetic field sensor 102 can be calibrated on the semiconductor module 100 in an end-of-line test procedure prior to shipment. This results in improved accuracy compared to a customer calibration procedure because the end-of-line test procedure is performed in a controlled environment with multi-temperature calibration capability and may omit high-current calibration steps that are typically performed in the field.

[0033] The magnitude of the signal generated by the coreless magnetic field sensor 102 is proportional to the current flowing in the constricted region of the AC output terminal 114. Any type of coreless magnetic field sensor can be used. In one embodiment, the coreless magnetic field sensor 102 is a magnetoresistive (XMR) sensor, such as an anisotropic magnetoresistive (AMR) sensor, a giant magnetoresistive (GMR) sensor, or a tunnel magnetoresistive (TMR) sensor. In an XMR sensor, the specific electrical resistance of a metal, semimetal, or semiconductor 102 contained within the sensor changes under the influence of a magnetic field and is proportional to the current flowing in the constricted region of the AC output terminal 114. In another embodiment, the coreless magnetic field sensor 102 is a Hall sensor.In the case of a Hall sensor, a transducer contained in the sensor 102 has an output voltage that changes depending on the magnetic field and proportionally to the current flowing in the narrowed area of ​​the AC output terminal 114.

[0034] After the in Fig. In the embodiment shown in Figure 1, the potting compound 108 has a recess 118 near the narrowed area of ​​the AC output terminal 114. The coreless magnetic field sensor 102 is arranged in the recess 118 of the potting compound 108. In one embodiment, the potting compound 108 has a projection 120 that covers more of the AC output terminal 114 than of the other terminals 112 that project from the same side of the potting compound 108 as the AC output terminal 114. The recess 118 of the potting compound 108 is formed in the projection 120.

[0035] Fig. Figure 2 shows the embodiment of a method for producing the in Fig. Figure 1 shows a semiconductor module 100. The method involves electrically connecting the terminals 110, 112, 114 to one or more semiconductor chips 104, 106 (block 200). For example, the terminals 110, 112, 114 can be electrically connected to the semiconductor chip(s) 104, 106 by bond wires, metal strips, metal clips, etc. The method further comprises potting the terminals 110, 112, 114 and the one or more semiconductor chips 104, 106, such that the one or more semiconductor chips 104, 106 are enclosed in the potting compound 108 and the terminals 110, 112, 114 protrude from the potting compound 108, the AC output terminal 114 has a constricted area covered by the potting compound 108, and the potting compound 108 has a recess 118 near the constricted area of ​​the AC output terminal 114 (block 210). Any typical potting method can be used, such as…Injection molding, film-assisted potting, transfer molding, etc. A pin in a potting tool can be used to form the projection 120 of the potting compound 108. The process also involves placing the coreless magnetic field sensor 102 into the recess 118 of the potting compound 108 (block 220). The coreless magnetic field sensor 102 can be secured in the recess by adhesive, tape, etc., or clipped in by the shape and texture of the recess 118.

[0036] Fig. Figure 3A shows an enlarged view of a section of the semiconductor module 100 before the coreless magnetic field sensor 102 is positioned in the recess 118 of the potting compound 108. Fig. Figure 3B shows the same view of semiconductor module 100 as in Fig. 3A, however, after the coreless magnetic field sensor 102 was placed in the recess 118. Fig. 3C shows a partial cross-section of the semiconductor module 100 along the in Fig. 1 line labelled AA'. The semiconductor module 100 can be a first substrate 122, such as a PCB (printed circuit board) or DCB (direct copper bonded) substrate, to which the high-side power semiconductor chip 104 (in Fig. 3C not visible) is attached, and a second substrate 124, such as a PCB or DCB substrate, to which the low-side power semiconductor chip 106 (in Fig. 3C (also not visible) is included. In this configuration, the semiconductor module 100 can have double-sided cooling.

[0037] In an arrangement of stacked DCB substrates 122, 124, for example, each DCB substrate 122, 124 has two metallized surfaces 126, 128, separated by an insulating substrate 130 such as ceramic. The top metallized side 126 of the upper DCB substrate 122 provides cooling on one side of the semiconductor module 100, while the bottom metallized side 126 of the lower DCB substrate 124 provides cooling on the opposite side of the module 100. Double-sided cooling can also be achieved by using PCB substrates 122, 124. Double-sided cooling is advantageous for high-performance applications such as in automotive power electronics. One or more semiconductor chips 104, 106 can be mounted on the same substrate instead of on separate substrates.

[0038] Furthermore, the coreless magnetic field sensor 102 can be configured according to the embodiment of Fig. 3C is an asymmetric or differential sensor arranged in the recess 118 of the potting compound 108. In the case of a differential sensor, the coreless magnetic field sensor 102 has a first sensor element 132 positioned next to a first side of the constricted area 134 of the AC output terminal 114, and a second sensor element 136 positioned next to a second side of the constricted area 134 opposite the first side. The coreless differential magnetic field sensor 102 generates a signal that is a linear function of the differential flux density of the magnetic field passing through the first and second sensor elements 132, 136. One of the sensor elements 132, 136 can be omitted, for example, in low-noise applications to obtain an asymmetric coreless magnetic field sensor 102.In this embodiment, a single sensor element 132 (or 136) is positioned next to one side of the constricted area 134 of the AC output terminal 114 of the semiconductor module 100. In the case of a differential or asymmetric sensor, the sensor element(s) 132, 136 of the coreless magnetic field sensor 102 can be mounted on a substrate 138, e.g., a printed circuit board, on which the terminals 116 of the sensor 102 are also mounted. In both cases, each sensor element 132, 136 of the coreless magnetic field sensor 102 is insulated from the constricted area 134 of the AC output terminal 114 by the potting compound 108 to ensure proper electrical insulation and accurate detection of the current flowing in the constricted area 134 of the terminal 114.

[0039] Fig. Figure 4 shows an embodiment of the portion of the AC output terminal 114 that is covered by the potting compound 108 and has the narrowed area 134. The potting compound 108 is in Fig. Figure 4 is not shown to allow an unobstructed view of the narrowed area 134. According to this embodiment, the narrowed area 134 of the AC output terminal 114 is a tapered area 300 over which the width of the terminal 114 tapers from a larger width W1 to a smaller width W2. In the case of a coreless differential magnetic field sensor 102, the sensor 102 has sensor elements 132, 136 arranged next to opposite sides of the tapered area 300 of the AC output terminal 114. In the case of an asymmetric coreless magnetic field sensor 102, one of the elements shown in Figure 102 is omitted. Fig. 4 sensor elements 132 (or 136) shown. In both cases, the recess 118 of the potting compound 108 is located near the tapered area 300 of the AC output terminal 114, and the (differential or asymmetric) coreless magnetic field sensor 102 is arranged in the recess 118 of the potting compound 108, e.g., as in Fig. 1 and Fig. 3A-3C shown.

[0040] Fig. Figure 5 shows a further embodiment of the part of the AC output terminal 114 that is covered by the potting compound 108 and has the narrowed area 134. The potting compound 108 is in Fig. 5 is not shown to allow an unobstructed view of the constricted area 134. According to this representation, the constricted area 134 of the AC output terminal 114 is a winding area 400 of the terminal 114 that twists or turns in one direction and then in the other. In the case of a coreless differential magnetic field sensor 102, the sensor 102 has sensor elements 132, 136 positioned next to opposite sides of the serpentine area 400 of the AC output terminal 114. In the case of an asymmetric coreless magnetic field sensor 102, one of the elements shown in Figure 102 is omitted. Fig. 5 sensor elements 132 (or 136) shown. In both cases, the recess 118 of the potting compound 108 is located near the coiled area 400 of the AC output terminal 114, and the (differential or asymmetric) coreless magnetic field sensor 102 is arranged in the recess 118 of the potting compound 108, e.g., as in Fig. 1 and Fig. 3A-3C shown.

[0041] The embodiments described above offer lateral integration of a coreless magnetic field sensor, enabling minimal height and maximum field measurement. However, the laterally integrated sensor structure can represent a significant bottleneck for the current in the AC output terminal of the semiconductor module. The resulting higher power dissipation can limit the maximum output current capability of the semiconductor module. Next, an embodiment of a semiconductor module with vertical integration of a coreless magnetic field sensor is described. The vertically integrated sensor structure offers lower insertion resistance at the cost of reduced sensor field strength.

[0042] Fig. Figure 6 shows another embodiment of a semiconductor module 500 with an integrated, coreless, open-loop current sensor 102. The in Fig. The embodiment shown in 6 is similar to the one in Fig. 1. In contrast, the narrowed area 134 of the AC output terminal 114 is an area of ​​the terminal with an opening which is in Fig. 6 is not visible. According to this embodiment, the potting compound 108 has an opening 502 that is aligned with the opening in the AC output terminal 114. The coreless magnetic field sensor 102 is arranged in the opening 502 of the potting compound 108. The potting compound 108 covers the side wall of the opening in the AC output terminal 114 and thereby insulates the coreless magnetic field sensor 102 from the side wall of the opening in the AC output terminal 114. In one embodiment, the potting compound 108 has a projection 120 that covers more of the AC output terminal 114 than of the other terminals 112 that project from the same side of the potting compound 108 as the AC output terminal 114. The opening 502 of the potting compound 108 is formed in the projection 120.

[0043] The in Fig. The two methods shown can be used to produce the in Fig. The semiconductor module 500 shown in Figure 6 can be used. However, the coreless magnetic field sensor 102 is placed in the opening 502 of the potting compound 108 instead of in a recess. The coreless magnetic field sensor 102 can be attached to the opening 502 of the potting compound 108 using adhesive, tape, etc., or clipped into the opening 502.

[0044] Fig. Figure 7A shows an enlarged view of a section of the Fig. 6 semiconductor module 500 shown, before the coreless magnetic field sensor 102 is arranged in the opening 502 of the potting compound 108. Fig. Figure 7B shows the same view of the 500 semiconductor module as in Fig. 7A, however, after the coreless magnetic field sensor 102 was inserted into the opening 502 of the potting compound 108. Fig. Figure 7C shows a partial cross-section of the semiconductor module 500 along the line labeled BB' in Fig. 6.

[0045] In one embodiment, the coreless magnetic field sensor 102 is a differential sensor arranged in the opening 502 of the potting compound 108 and comprises a first sensor element 132 positioned above the opening 504 in the AC output terminal 114 of the semiconductor module 500, and a second sensor element 136 positioned below the opening 504 in the AC output terminal 114. In another embodiment, the coreless magnetic field sensor 102 is an asymmetric sensor. In this embodiment, one of the elements described in Fig. 7C shown sensor elements 132 (or 136). In the case of a differential or asymmetric sensor, each sensor element 132, 136 of the coreless magnetic field sensor 102 is insulated from the side wall 506 of the opening 504 in the AC output terminal 114 by the potting compound 108 to ensure proper electrical insulation and accurate detection of the current flowing in the constricted region 134 of the AC output terminal. Fig. Figure 7D shows the portion of the AC output terminal 114 covered by the potting compound 108 and featuring the opening 504 into which the coreless magnetic field sensor 102 is inserted. The potting compound 108 is in Fig. 7D not shown to allow an unobstructed view of the opening 504 and the corresponding narrowed area 134.

[0046] Fig. Figure 8 shows an embodiment of a cooling system 600, which contains a plurality of individual semiconductor modules of the type described above. The individual semiconductor modules are arranged in Fig. 8 not visible and can the in the Fig. 1 and 3A-3C shown lateral integrated sensor structure or the one shown in the Fig. Figures 6 and 7A-7C show a vertical integrated sensor structure. That is, each individual semiconductor module can comprise one or more semiconductor chips, a potting compound encasing each semiconductor chip, a plurality of terminals 602 electrically connected to the semiconductor chip(s) and protruding from the potting compound, a first of the terminals having a constricted region covered by the potting compound, the potting compound having a recess or opening near the constricted region of the first terminal, and a coreless magnetic field sensor arranged in the recess or opening of the potting compound and insulated from the first terminal by the potting compound.The coreless magnetic sensor is configured to generate a signal in response to a magnetic field generated by a current flowing in the constricted region of the first terminal, the magnitude of the signal being proportional to the strength of the current flowing in the constricted region of the first terminal, as previously explained here.

[0047] The cooling system 600 further comprises a first cover 604, which is connected to a second cover 606 to form a sealed housing. The sealed housing contains the individual semiconductor modules and a cavity between the covers and the individual semiconductor modules. The cavity is in Fig.Figure 8 is not visible. The first cover 604 has one or more ports 608, and the second cover 606 has one or more ports 610, allowing a fluid such as water, coolant, etc., to flow into the cavity between the covers 604, 606, and the individual semiconductor modules. With two-sided cooling, the fluid can flow along both main sides of the individual semiconductor modules. With asymmetrical cooling, the fluid must only flow along the main side of the individual semiconductor modules with the cooling structure. The cover 604, 606 adjacent to the side of the individual semiconductor modules without a cooling structure must not have any ports. The covers 604, 606 can be made of metal or plastic, or a combination of metal and plastic.

[0048] Terms like "first," "second," and the like are used to describe different elements, areas, sections, etc., and are not intended to be restrictive. The same terms refer to the same elements throughout the entire description.

[0049] In the form used here, the terms "have," "contain," "include," "comprise," and the like are open terms that indicate the presence of the specified elements or features but do not exclude additional elements or features. The articles "a," "an," and "the" are intended to include both the plural and the singular unless the context clearly indicates otherwise.

[0050] It should be understood that the features of the various embodiments described here can be combined with one another, unless expressly stated otherwise.

Claims

[1] A semiconductor module comprising: a semiconductor chip; a potting compound that encases the semiconductor chip; a plurality of terminals electrically connected to the semiconductor chip and protruding from the potting compound, wherein a first of the terminals has a constricted region covered by the potting compound, the potting compound having a recess or opening near the constricted region of the first terminal; and a coreless magnetic field sensor arranged in the recess or opening of the potting compound and insulated from the first terminal by the potting compound, wherein the coreless magnetic sensor is configured to generate a signal in response to a magnetic field generated by a current flowing in the constricted region of the first terminal, the magnitude of the signal being proportional to the current flowing in the constricted region of the first terminal. [2] Semiconductor module according to claim 1, wherein the coreless magnetic field sensor is a magnetoresistive sensor or a Hall sensor. [3] Semiconductor module according to claim 1 or 2, wherein the narrowed area of ​​the first terminal has a tapered region over which the width of the first terminal narrows, wherein the recess of the potting compound is located near the tapered region of the first terminal, wherein the coreless magnetic field sensor is an asymmetric sensor arranged in the recess of the potting compound and has a single sensor element arranged on one side of the tapered region, and wherein the single sensor element is isolated from the tapered region by the potting compound. [4] Semiconductor module according to one of the preceding claims, wherein the narrowed region of the first terminal has a tapered area over which the width of the first terminal narrows, wherein the recess of the potting compound is located near the tapered area of ​​the first terminal, wherein the coreless magnetic field sensor is a differential sensor arranged in the recess of the potting compound and has a first sensor element positioned adjacent to a first side of the tapered area, and a second sensor element positioned adjacent to a second side of the tapered area opposite the first side, and wherein the first and second sensor elements are isolated from the tapered area by the potting compound. [5] Semiconductor module according to one of the preceding claims, wherein the narrowed area of ​​the first terminal comprises a coiled area, wherein the recess of the potting compound is located near the coiled area of ​​the first terminal, wherein the coreless magnetic field sensor is an asymmetric sensor arranged in the recess of the potting compound and comprises a single sensor element arranged next to one side of the coiled area, and wherein the single sensor element is isolated from the coiled area by the potting compound. [6] Semiconductor module according to one of the preceding claims, wherein the narrowed area of ​​the first terminal has a coiled region, wherein the recess of the potting compound is located near the coiled region of the first terminal, wherein the coreless magnetic field sensor is a differential sensor arranged in the recess of the potting compound and has a first sensor element positioned adjacent to a first side of the coiled region, and a second sensor element positioned adjacent to a second side of the coiled region opposite the first side, and wherein the first and second sensor elements are isolated from the coiled region by the potting compound. [7] Semiconductor module according to one of the preceding claims, wherein the narrowed region of the first terminal comprises a region of the first terminal with an opening, wherein the opening of the potting compound is aligned with the opening in the first terminal, wherein the coreless magnetic field sensor is an asymmetric sensor arranged in the opening of the potting compound and comprises a single sensor element arranged above or below the opening in the first terminal, and wherein the single sensor element is insulated from a side wall of the opening in the first terminal by the potting compound. [8] Semiconductor module according to one of the preceding claims, wherein the narrowed region of the first terminal comprises a region of the first terminal with an opening, wherein the opening of the potting compound is aligned with the opening in the first terminal, wherein the coreless magnetic field sensor is a differential sensor arranged in the opening of the potting compound and comprises a first sensor element arranged above the opening in the first terminal and a second sensor element arranged below the opening in the first terminal, and wherein the first and the second sensor element are insulated from a side wall of the opening in the first terminal by the potting compound. [9] Semiconductor module according to any of the preceding claims, wherein the potting compound has a projection which covers more of the first terminal than of any of the other terminals which protrude from the same side of the potting compound as the first terminal, and wherein the recess or opening of the potting compound is formed in the projection. [10] Semiconductor module according to any of the preceding claims, wherein the semiconductor chip is a power semiconductor chip, wherein the semiconductor module has double-sided cooling, and wherein the first terminal is an AC output terminal of the power semiconductor chip. [11] A cooling system comprising: a plurality of individual semiconductor modules, each comprising: a semiconductor chip; a potting compound encasing the semiconductor chip; a plurality of terminals electrically connected to the semiconductor chip and protruding from the potting compound, a first of the terminals having a constricted region covered by the potting compound, the potting compound having a recess or opening near the constricted region of the first terminal;and a coreless magnetic field sensor arranged in the recess or opening of the potting compound and insulated from the first terminal by the potting compound, wherein the coreless magnetic sensor is configured to generate a signal in response to a magnetic field generated by a current flowing in the constricted region of the first terminal, the magnitude of the signal being proportional to the current strength flowing in the constricted region of the first terminal; and; a first cover connected to a second cover to form a sealed enclosure containing the plurality of individual semiconductor modules and a cavity between the covers and the individual semiconductor modules for a fluid flow through a plurality of openings formed in the first and / or second cover. [12] Cooling system according to claim 11, wherein each coreless magnetic field sensor is a magnetoresistive sensor or a Hall sensor. [13] Cooling system according to claim 11 or 12, wherein the narrowed area of ​​each first connection has a tapered area over which the width of the first connection tapers, wherein the recess of the potting compound is located near the tapered area of ​​the first connection, wherein the coreless magnetic field sensor is an asymmetric sensor arranged in the recess of the potting compound and has a single sensor element arranged adjacent to one side of the tapered area, and wherein the single sensor element is isolated from the tapered area by the potting compound. [14] Cooling system according to one of claims 11 to 13, wherein the narrowed region of each first connection comprises a tapered area over which the width of the first connection narrows, wherein the recess of the potting compound is located near the tapered area of ​​the first connection, wherein the coreless magnetic field sensor is a differential sensor arranged in the recess of the potting compound and comprising a first sensor element arranged adjacent to a first side of the tapered area, and comprising a second sensor element arranged adjacent to a second side of the tapered area opposite the first side, and wherein the first and second sensor elements are insulated from the tapered area by the potting compound. [15] Cooling system according to one of claims 11 to 14, wherein the narrowed area of ​​each first connection comprises a coiled area, wherein the recess of the potting compound is located near the coiled area of ​​the first connection, wherein the coreless magnetic field sensor is an asymmetric sensor arranged in the recess of the potting compound and comprises a single sensor element arranged next to one side of the coiled area, and wherein the single sensor element is isolated from the coiled area by the potting compound. [16] Cooling system according to one of claims 11 to 15, wherein the narrowed area of ​​each first connection comprises a coiled area, wherein the recess of the potting compound is located near the coiled area of ​​the first connection, wherein the coreless magnetic field sensor is a differential sensor arranged in the recess of the potting compound and comprises a first sensor element arranged adjacent to a first side of the coiled area, and a second sensor element arranged adjacent to a second side of the coiled area opposite the first side, and wherein the first and second sensor elements are isolated from the coiled area by the potting compound. [17] Cooling system according to one of claims 11 to 16, wherein the narrowed area of ​​each first connection comprises an area of ​​the first connection with an opening, wherein the opening of the potting compound is aligned with the opening in the first connection, wherein the coreless magnetic field sensor is an asymmetric sensor arranged in the opening of the potting compound and comprises a single sensor element arranged above or below the opening in the first connection, and wherein the single sensor element is insulated from a side wall of the opening in the first connection by the potting compound. [18] Cooling system according to one of claims 11 to 17, wherein the narrowed area of ​​each first connection comprises an area of ​​the first connection with an opening, wherein the opening of the potting compound is aligned with the opening in the first connection, wherein the coreless magnetic field sensor is a differential sensor arranged in the opening of the potting compound and comprises a first sensor element arranged above the opening in the first connection and a second sensor element arranged below the opening in the first connection, and wherein the first and the second sensor element are insulated from a side wall of the opening in the first connection by the potting compound. [19] Cooling system according to any one of claims 11 to 18, wherein the potting compound of each individual semiconductor module has a projection that covers more of the first terminal than of any of the other terminals that protrude from the same side of the potting compound as the first terminal, and wherein the recess or opening of the potting compound is formed in the projection. [20] Cooling system according to any one of claims 11 to 19, wherein each semiconductor chip is a power semiconductor chip, wherein each individual semiconductor module has double-sided cooling, and wherein each first terminal is an AC output terminal of the power semiconductor chip. [21] Method for manufacturing a semiconductor module, the method comprising: electrically connecting a large number of terminals to a semiconductor chip; Potting the plurality of terminals and the semiconductor chip such that the semiconductor chip is enclosed in a potting compound and the plurality of terminals protrudes from the potting compound, wherein a first of the terminals has a constricted region which is covered by the potting compound, wherein the potting compound has a recess or an opening near the constricted region of the first terminal; and Attaching a coreless magnetic field sensor in the recess or opening of the potting compound, wherein the coreless magnetic field sensor is isolated from the first terminal by the potting compound and is configured to generate a signal in response to a magnetic field generated by a current flowing in the constricted region of the first terminal, wherein the magnitude of the signal is proportional to the current strength of the current flowing in the constricted region of the first terminal.

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