TWI898419B - Power module - Google Patents

Abstract

The disclosure provides a power module, including a leadless frame substrate including a first metal layer and an insulating layer, wherein the first metal layer forms a circuit trace disposed on the insulating layer and the first metal layer has an extension structure extending out of the insulating layer to serve as an output terminal; at least one semiconductor power device disposed on the first metal layer; a current detector disposed on the output terminal; and a molding compound, completely covering the first metal layer on the insulating layer of the leadless frame substrate and the at least one semiconductor power device, and partially covering the output terminal so that the current detector is completely disposed outside the mold compound.

Description

Power Module

The present disclosure relates to a power module, and more particularly to a power module with a current detector.

In existing circuit system applications, it is necessary to monitor the output and input currents of power modules during operation. One approach is to attach a current detector to the output terminals of the power module, for example, by fixing the current detector to a lead frame or bus bar at the output end of the power module using a plastic frame or circuit board.

For users, calibrating the current detector signal after installation is a time-consuming and tedious process. For example, downstream power equipment assemblers often manually attach or assemble current detectors to power modules, leading to significant positioning errors after each installation. This results in significant signal variation between current detectors on each power module, necessitating time-consuming post-installation signal calibration. A common method for mounting current detectors is to place the current detector on a circuit board, align the board with the output pins of the power module, and use a U-shaped ring to strengthen the magnetic field to improve signal strength. However, this still does not solve the problem of signal variation caused by inaccurate positioning. Furthermore, the U-shaped ring is complex to assemble and takes up a lot of space.

To solve the above-mentioned problems in the prior art, the present disclosure provides a power module that can effectively solve the problem of large positioning errors of current detection devices in the prior art.

One embodiment of the present disclosure provides a power module comprising: a leadframe-less substrate, at least one semiconductor power device, a current detector, and a molding compound. The leadframe-less substrate includes a first metal layer and an insulating layer, wherein the first metal layer forms a circuit trace disposed on the insulating layer and the first metal layer has an extension structure extending out of the insulating layer to serve as an output terminal. The at least one semiconductor power device is disposed on the first metal layer. The current detector is disposed on the output terminal. The portion of the first metal layer located on the insulating layer is completely covered by the molding compound, the at least one semiconductor power device is completely covered by the molding compound, and the molding compound partially covers the output terminal, leaving the current detector completely exposed outside the molding compound. The power module is used to convert DC power into AC power, output the AC power through the output end, and detect the AC power through the current detector.

In the power module according to one embodiment of the present disclosure, the magnetic susceptibility of the first metal layer is less than 1 and greater than 0.

In the power module according to one embodiment of the present disclosure, the leadframe-free substrate further includes a second metal layer disposed under the insulating layer, and the molding compound partially covers the second metal layer.

In the power module according to one embodiment of the present disclosure, the current detector is fixed on the output end with the assistance of a robotic arm.

The present disclosure also provides a power module comprising: a lead frame substrate, at least one semiconductor power device, a current detector, and a molding compound. The lead frame substrate includes a first metal layer and an insulating layer, wherein the first metal layer forms a circuit trace, the circuit trace is arranged on the insulating layer and has an output end. The at least one semiconductor power device is arranged on the circuit trace. The current detector is arranged on the output end. The molding compound completely covers the first metal layer of the lead frame substrate, the at least one semiconductor power device, and the current detector. The power module is used to convert direct current (DC) power into alternating current (AC) power, output the AC power through the output end, and detect the AC power by the current detector.

In the power module according to one embodiment of the present disclosure, the magnetic susceptibility of the first metal layer is less than 1 and greater than 0.

In the power module according to one embodiment of the present disclosure, the leadframe-free substrate further includes a second metal layer disposed under the insulating layer, and the molding compound partially covers the second metal layer.

In the power module according to one embodiment of the present disclosure, the current detector is fixed on the output end with the assistance of a robotic arm.

The power module according to one embodiment of the present disclosure further includes a lead frame connected to the output end.

The power module described in one embodiment of the present disclosure further includes a pin structure disposed on the first metal layer, wherein the current detector is a surface-mounted component, and the signal end of the component is electrically connected to the pin structure via the circuit trace.

In the power module according to one embodiment of the present disclosure, the signal end of the current detector is electrically connected to the first metal layer via a bonding wire.

The power module described in one embodiment of the present disclosure further includes a multi-layer substrate circuit structure disposed on the first metal layer.

In the power module according to one embodiment of the present disclosure, the multi-layer substrate circuit structure extends outside the molding compound, and the signal terminal of the current detector is electrically connected to the multi-layer substrate circuit structure via a wiring.

The power module described in one embodiment of the present disclosure further includes a pin structure disposed on the multi-layer substrate circuit structure, and the signal end of the current detector is electrically connected to the multi-layer substrate circuit structure via a wiring and is electrically connected to the pin structure via the multi-layer substrate circuit structure.

Compared to prior art, the power module structure disclosed herein utilizes precise packaging technologies such as surface mount technology (SMT), enabling the precise mounting of the current detector at the output terminal, providing a pre-installed power module. Because the current detector's positioning error is minimal, the initial calibration data from the sensed signal can be directly applied, eliminating the need to recalibrate the current detector signal for each power module, effectively avoiding the problems associated with prior art.

To make the features and advantages of this disclosure more readily apparent, preferred embodiments of the disclosure are described below in detail with reference to the accompanying drawings. Furthermore, the directional terms used in this disclosure are intended to facilitate understanding and are not intended to limit this disclosure. In the figures, similarly structured elements are denoted by the same reference numerals.

2A and 2B , a first embodiment of the present disclosure provides a power module 100 comprising a leadframe-less substrate 10, at least one semiconductor power device 20, a current detector 30, and a molding compound 40. The leadframe-less substrate 10 includes a first metal layer 12 and an insulating layer 14. Specifically, the leadframe-less substrate 10 is a composite material substrate composed of multiple material layers. The first metal layer 12 forms a circuit trace (121, 122, 16) disposed on the insulating layer 14, and the first metal layer 12 has an extension structure 122 extending from the insulating layer 14 to serve as an output terminal 16. The at least one semiconductor power device 20 is disposed on the first metal layer 12. The current detector 30 is disposed on the output terminal 16. The molding compound 40 completely covers the first metal layer 12 and the at least one semiconductor power device 20 of the leadframe-free substrate 10 located on the insulating layer 14, and partially covers the output terminal 16, leaving the current detector 30 completely exposed outside the molding compound 40. The power module 100 is configured to convert DC power into AC power, output the AC power through the output terminal 16, and detect the AC power using the current detector 30.

Referring to Figure 1, the conventional power module p100 uses a lead-frame substrate (also called a lead-frame substrate), which is different from the multiple material layers of the lead-frame substrate 10 disclosed in the present invention (as shown in Figure 2B). In the conventional technology of Figure 1, the circuit trace p12 covered by the molding compound p40 and the extended structure p122 extending out of the molding compound p40 are formed entirely with the lead frame p10, and the extended structure p122 is used as the input terminal p121 or the output terminal p16 of the power module. The current detector p30 is arranged on the output terminal p16. The semiconductor power device p20 is arranged on the heat sink p18. However, the lead frame p10 is manufactured by metal stamping and cannot provide the precise positioning required for the current detector disclosed in the present invention. The present invention uses a lead-off substrate 10, which is characterized by extending a metal surface of a composite material layer substrate beyond the insulating layer to form a connection component to serve as the input or output terminal of the power module.

Referring to Figures 2A and 2B, in one embodiment, the lead-off substrate 10 is a ceramic substrate, and its first metal layer 12 is formed into circuit traces by casting and etching, for example, copper or aluminum, with high positioning and shape accuracy. Its thickness is generally between 0.5 and 0.8 mm, and can be as high as 1.2 mm. Compared to the circuit layer of a conventional circuit board, the first metal layer 12 is thicker and can extend beyond the insulating layer 14 without the support of the underlying insulating layer 14 to serve as an output or input pin or plug. The thicker first metal layer 12 can also be suitable for the larger operating voltages and currents of semiconductor power devices. The insulating layer 14 is made of, for example, ceramic, which provides both insulation and heat resistance. The leadless frame substrate 10 is suitable for use in high-heat and vibration environments in the power industry. Using the leadless frame substrate 10 can reduce the size of power modules and increase power density.

Referring to Figures 2A and 2B , in one embodiment, the first metal layer 12 forms circuit traces (121, 122, 16) disposed on the insulating layer 14. These traces include, for example, two input terminals 121 for introducing DC potential to provide the input potential required by the semiconductor power device 20, and an extension structure 122 extending from the insulating layer 14 to serve as three output terminals 16 for extracting the three-phase AC power outputted by the semiconductor power device 20. The specific circuit traces can be designed based on actual needs. The semiconductor power device 20 outputting three-phase AC power is merely an example. The three output terminals 16 shown in Figure 2A are also merely an example; the type of AC power and the number of output terminals 16 can be designed as needed. The AC power can be single-phase two-wire, single-phase three-wire, or two-phase, three-phase, four-phase, six-phase, etc., but the present invention is not limited thereto.

2A and 2B , the semiconductor power device 20 is, for example, a DC-to-AC converter. It can be mounted on two input terminals 121 formed by the first metal layer 12 using surface mount technology (SMT), or the semiconductor power device 20 can be electrically connected to the two input terminals 121 using bonding wires (also known as wire bonding). The output terminal of the semiconductor power device 20 can be electrically connected to the corresponding output terminal 16 using bonding wires or surface mounting. The present disclosure is not limited to this ( FIG. 2A shows that the semiconductor power device 20 is mounted on the two input terminals 121 using surface mount technology, and the output terminal of the semiconductor power device 20 is electrically connected to the corresponding output terminal 16 using bonding wires). One or more semiconductor power devices 20 can be provided as needed. Other electronic components may be disposed in the power module 100 as required, but the present disclosure is not limited thereto.

2A and 2B , the current detector 30 is, for example, a Hall effect current detector or a magnetoresistive (IM) current detector. A current detector packaged using surface mount technology is preferred, and the current detector 30 can be placed on the output terminal 16 using a robotic arm using surface mount technology or semiconductor chip die bonding technology. This significantly improves the positioning accuracy of the current detector 30. Current detectors are generally classified as contact-type (e.g., Hall effect detectors) and contactless-type (e.g., magnetoresistive detectors). Contact-type current detectors have a detection current input and a detection current output for the current to be detected to flow into the current detector. Contactless current detectors do not require a detection current input or output terminal. A Hall current detector typically has four signal terminals: a positive terminal and a negative terminal (ground) that provide the detector's operating potential, as well as a signal output terminal and a reference potential terminal for outputting the detection signal. Magnetoresistive detectors generally only require a signal output terminal and a reference potential terminal. However, this disclosure is not limited to this; the number of terminals in a current detector can be adjusted based on actual needs.

2A and 2B , in one embodiment, the molding compound 40 includes a polymer or resin, such as epoxy, acrylonitrile butadiene styrene (ABS), polycarbonate (PC), or polyurethane (PU), although the present disclosure is not limited thereto. The molding compound 40 completely covers the portion of the first metal layer 12 located on the insulating layer 14 and the semiconductor power device 20 to protect them. Furthermore, the molding compound 40 partially covers the output terminal 16, leaving the current detector 30 completely exposed outside the molding compound 40.

Referring to FIG. 2B , in one embodiment, to ensure precise positioning of the current detector 30, the current detector is not conventionally secured to a circuit board and then locked to the power module 100. Instead, the current detector 30 is first secured to the output terminal 16 using surface mounting or die bonding techniques. A circuit board 80 equipped with a spring or clip structure 84 is then press-fitted to the signal terminal of the current detector 30 for electrical connection, and the circuit board 80 is secured using locking holes 82. This avoids the inaccurate positioning of the current detector 30 that can occur when manually locking the circuit board 80.

In the power module 100 described in one embodiment of the present disclosure, the magnetic susceptibility of the first metal layer 12 is less than 1 and greater than 0. Specifically, to prevent the magnetization of the first metal layer 12 from causing an additional impact on the signal of the current detection device 30 or generating magnetic hysteresis that may cause signal deviation of the current detection device 30 in the future, the first metal layer 12 is preferably made of a non-ferrous metal or a conductive material with a magnetic susceptibility less than 1 and greater than 0, such as copper or aluminum.

Referring to FIG. 2B , a power module 100 according to one embodiment of the present disclosure includes a leadframe-free substrate 10 further comprising a second metal layer 18 disposed beneath the insulating layer 14, with the molding compound 40 partially encapsulating the second metal layer 18. Specifically, the second metal layer can be used to contact a heat sink, heat pipe, fan, or the like to dissipate heat from the power module 100.

In the power module of one embodiment of the present disclosure, the current detector 30 is fixed to the output terminal 16 with the assistance of a robot. Specifically, the current detector 30 is fixed to the output terminal 16 with the robot using surface mounting or die bonding technology.

Die bonding involves attaching a die or component to a specific material using various processes, including adhesive, heat, pressure, or ultrasound. Die bonding techniques include adhesive die bonding and eutectic processes, which are further categorized as thermos-compression die bonding and thermosonic die bonding.

Adhesive bonding involves attaching the die (in this case, the current detector) to a substrate or material using an adhesive material. The adhesive material can be conductive or non-conductive. Before the process, the adhesive is removed from a cryogenic freezer and returned to room temperature to form a liquid. Automatic dispensing equipment is then used to apply the adhesive to the substrate or material, placing the die on top. After the die is placed, the die is placed in an oven to dry and solidify the adhesive, completing the die bonding process.

The eutectic process is to bond two identical or different metals to achieve electrical conductivity. In this disclosure, the pads on the current detector 30 package are metal-bonded to the first metal layer. The hot press die bonding process provides heat energy to the solder layer to melt the solder into a liquid state. The other welding point provides a temperature just below the melting point of the solder. The liquefied solder penetrates into the other bonding surface metal to form an intermetallic bond, also known as wetting. To prevent the liquid solder from causing the object to shift, pressure can be applied from above to fix the welded object when the two contacts are bonded. The use of a soldering agent can increase the optimal metal bond. The most commonly used solder in the hot press die bonding process in the industry is gold-tin.

Hot-press ultrasonic die bonding utilizes mechanical ultrasonic vibrations to provide energy to bond two metals. Gold-to-metal bonding is the most commonly used metal. Conventional hot-press die bonding requires temperatures exceeding 270°C, which can easily damage substrates or sensitive chips. Hot-press ultrasonic bonding significantly reduces the die bonding temperature to less than 150°C, eliminating the need for solder flux and post-solder cleaning procedures.

3 and 4, a second embodiment of the present disclosure provides a power module 200, comprising: a leadless frame substrate 10, including a first metal layer 12 and an insulating layer 14, wherein the first metal layer 12 forms a circuit trace (121, 15, 16) disposed on the insulating layer 14 and the circuit trace (121, 15, 16) has an output end 16; at least one semiconductor power device 20, disposed on the circuit trace 1 21; a current detector 30 disposed on the output terminal 16; and a molding compound 40 completely covering the first metal layer 12 of the leadless frame substrate 10, the at least one semiconductor power device 20, and the current detector 30; wherein the power module 200 is used to convert DC power into AC power, output the AC power through the output terminal 16, and detect the AC power by the current detector 30.

Referring to Figures 3 and 4 , power module 200 is similar to power module 100 , with the primary difference being that mold compound 40 in power module 200 completely encapsulates current detector 30 . Other components similar to those in power module 100 are described in the corresponding paragraphs above and in Figures 2A and 2B , and are not further described here. Complete encapsulation of current detector 30 by mold compound 40 provides structural and positioning protection for current detector 30 .

3 and 4 , a power module 200 according to a second embodiment of the present disclosure is described, wherein the magnetic susceptibility of the first metal layer 12 is less than 1 and greater than 0. In a power module 200 according to an embodiment of the present disclosure, the leadframe-free substrate 10 further includes a second metal layer 18 disposed beneath the insulating layer 14, and the molding compound 40 partially encapsulates the second metal layer 18. In a power module 200 according to an embodiment of the present disclosure, the current detector 30 is fixed to the output terminal 16 with the assistance of a robot.

Referring to Figures 3 and 4 , the power module 200 described in the second embodiment of the present disclosure further includes a lead frame 50 connected to the output terminal 16 . Specifically, in this embodiment, the output terminal 16 does not extend beyond the molding compound 40 . Instead, the lead frame 50 is welded to the output terminal 16 to provide power output. This ensures both the positioning accuracy of the current detector 30 and the structural strength of the lead frame 50 . The lead frame 50 can be electrically connected to and secured to the output terminal 16 by welding or sintering.

Referring to Figures 3 and 4 , in one embodiment, power module 200 further includes a signal pin 15 formed from the first metal layer 12 for electrically connecting to the signal terminal of current detector 30. Figures 3 and 4 illustrate the connection between the signal terminal of current detector 30 and signal pin 15 using a wire 32. However, the present disclosure is not limited to this embodiment; a surface mount method may also be used to connect the signal terminal of current detector 30 and signal pin 15.

Referring to Figures 3 and 4 , in one embodiment, power module 200 further includes a ceramic substrate, such as a multi-layer substrate circuit structure 60 disposed on the first metal layer 12. Multi-layer substrate circuit structure 60 can be, for example, a direct bonded copper (DBC) substrate or an active metal brazing (AMB) substrate, both of which are ceramic substrates. Multi-layer substrate circuit structures combine the heat dissipation properties of ceramics with the conductive properties of metals. After oxidizing copper foil, a thick copper foil is directly coated on the ceramic substrate using high-temperature sintering. The circuit pattern is then engraved on the copper foil through exposure and development. The multi-layer substrate circuit structure 60 can be constructed by staggering and overlapping multiple metal layers 62 and ceramic layers 64. For example, FIG4 illustrates only one metal layer 62 and one ceramic layer 64, but the present invention is not limited thereto. The ceramic layer 64 can also have through-holes to electrically connect the upper and lower metal layers 62. The signal terminal of the current detector 30 of the power module 200 is connected to the signal pin 15 by connecting the signal terminal of the current detector 30 to the metal layer 62 on the multi-layer substrate circuit structure 60 via a wire 32. The signal pin 15 is then connected via an interconnection in the multi-layer substrate circuit structure 60 (e.g., an interconnection in the through-hole of the ceramic layer 64, not shown).

Referring to Figures 5, 6, and 7, the power module 200' described in the third embodiment of the present disclosure differs from power module 200 in that power module 200' does not include a lead frame 50. Instead, the output terminal 16 extends directly from the molding compound 40. For example, the first metal layer 12 includes an extension structure 122 extending from the insulating layer 14 to serve as an output terminal 16. In various applications, the output terminal 16 formed by the thickened first metal layer 12 has sufficient strength to form a pin or plug for power output. Other components similar to those of power modules 100 and 200 are described in the corresponding paragraphs above and in Figures 2A to 4 and are not further described here.

Referring to FIG8 , the power module 220 described in the fourth embodiment of the present disclosure differs from the power module 200′ in that the signal pin 15 of the power module 200′ is replaced with a multi-layer substrate circuit structure 60 in the power module 220. The current detector 30 is electrically connected to the metal layer 62 of the multi-layer substrate circuit structure 60 via a wire 32. In addition to the stronger structural strength of the ceramic layer 64, the multi-layer substrate circuit structure 60 can be applied to more complex circuit designs. Other components similar to those of the power modules 100, 200, and 200′ are described in the corresponding paragraphs above and in FIG2A to FIG7 and are not further described here.

8 , the power module 220 according to the fourth embodiment of the present disclosure further includes a multi-layer substrate circuit structure 60 disposed on the circuit traces 124 of the first metal layer 12. In the power module 220 according to one embodiment of the present disclosure, the multi-layer substrate circuit structure 60 extends outside the molding compound 40, and the signal terminal of the current detector 30 is electrically connected to the multi-layer substrate circuit structure 60 via a wire 32.

9 , 10 , and 11 , the power module 200″ described in the fifth embodiment of the present disclosure differs from the power module 200′ in that the power module 200″ utilizes a pin structure 70 disposed on the first metal layer 12 to replace the signal pin 15 of the power module 200′. The current detector 30 is a surface mount component, and the signal end of the current detector 30 is electrically connected to the pin structure 70 via the circuit trace 123. Other components similar to the power modules 100, 200, 200′, and 220 are described in the corresponding paragraphs above and in Figures 2A to 8 and are not further described here.

9 , 10 , and 11 , the signal end of the current detector 30 is connected to the circuit trace 123 of the first metal layer 12 via the wiring 32 , and then electrically connected to the pin structure 70 disposed on the circuit trace 123 .

12 , the power module 240 described in the sixth embodiment of the present disclosure differs from the power module 200 ″ in that the pin structure 70 of the power module 240 is disposed on the multi-layer substrate circuit structure 60 , and the signal end of the current detector 30 is electrically connected to the metal layer 62 of the multi-layer substrate circuit structure 60 via the wiring 32 and is electrically connected to the pin structure 70 via the multi-layer substrate circuit structure 60 . Other components similar to the power modules 100, 200, 200 ′, 220, and 200 ″ are described in the corresponding paragraphs above and in FIG. 2A to FIG. 11 and are not further described here.

Compared to prior art, the power module structure disclosed herein utilizes precise packaging technologies such as surface mount technology, enabling the precise installation of the current detector at the output terminal, providing a power module pre-installed with the current detector. Because the current detector's positioning error is minimal, the initial calibration data from the sensed signal can be directly applied, eliminating the need to recalibrate the current detector signal for each power module, effectively avoiding the problems associated with prior art.

The above is only a preferred embodiment of the present disclosure. It should be pointed out that ordinary technical personnel in this field can make several improvements and modifications without departing from the principles of the present disclosure. These improvements and modifications should also be considered as the scope of protection of the present disclosure.

100, 200, 200', 200", 220, 240: Power module 10: Leadframe-less substrate 12: First metal layer 121: Input terminal 122: Extension structure 123, 124: Circuit traces 14: Insulation layer 15: Signal pins 16: Output terminal 18: Second metal layer 20: Semiconductor power device 30: Current detector 32: Wiring 40: Molding compound 60: Multi-layer substrate circuit structure 62: Metal layer 64: Ceramic layer 70: Pin structure 80: Circuit board 82: Attachment holes BB', CC', DD', EE', FF', GG': Cross-hatching p10: Leadframe p100: Power module p12: Circuit traces p121: Input terminals p122: Extension structure p16: Output terminals p18: Heat sink p20: Semiconductor power device p30: Current detector p40: Molding compound

FIG1 shows a schematic structural diagram of a conventional power module.

FIG2A is a schematic structural diagram of a power module according to the first embodiment of the present disclosure.

FIG2B shows a cross-sectional view of the power module of FIG2A along the BB' section line according to the present disclosure.

FIG3 shows a schematic structural diagram of a power module according to a second embodiment of the present disclosure.

FIG4 shows a cross-sectional view of the power module shown in FIG3 along the CC' section line according to the present disclosure.

FIG5 is a schematic structural diagram of a power module according to a third embodiment of the present disclosure.

FIG6 shows a cross-sectional view of the power module shown in FIG5 along the DD' section line according to the present disclosure.

FIG7 shows a cross-sectional view of the power module of FIG5 along the EE' section line according to the present disclosure.

FIG8 is a schematic diagram showing a partial cross-sectional structure of a power module according to a fourth embodiment of the present disclosure.

FIG9 is a schematic structural diagram of a power module according to a fifth embodiment of the present disclosure.

FIG10 shows a cross-sectional view of the power module shown in FIG9 along the FF' section line according to the present disclosure.

FIG11 shows a cross-sectional view of the power module of FIG9 along the GG' section line according to the present disclosure.

FIG12 is a schematic diagram showing a partial cross-sectional structure of a power module according to a sixth embodiment of the present disclosure.

100: Power module

10: Lead-less frame substrate

12: First metal layer

121: Input terminal

122: Extended Structure

14: Insulating layer

16: Output terminal

20: Semiconductor power devices

30: Current detector

40: Molding compound

80: Circuit board

82: Locking hole

Claims (14)

A power module comprises: A leadframe-less substrate, which is a composite material layer substrate composed of multiple material layers and does not include a leadframe. The multiple material layers of the leadframe-less substrate include an insulating layer and a first metal layer disposed on the insulating layer by casting and etching, wherein the first metal layer forms a circuit trace disposed on the insulating layer, and the first metal layer has an extension structure extending from the insulating layer to serve as an output terminal; At least one semiconductor power device disposed on the first metal layer; A current detector disposed on the output terminal; and A molding compound is provided, wherein the portion of the first metal layer located above the insulating layer is completely encapsulated by the molding compound, the at least one semiconductor power device is completely encapsulated by the molding compound, and the molding compound partially encapsulates the output terminal, leaving the current detector completely exposed outside the molding compound. The power module is configured to convert DC power into AC power, output the AC power through the output terminal, and detect the AC power using the current detector. The power module of claim 1, wherein the magnetic susceptibility of the first metal layer is less than 1 and greater than 0. The power module of claim 1, wherein the leadframe-free substrate further comprises a second metal layer disposed under the insulating layer, and the molding compound partially encapsulates the second metal layer. A power module as described in claim 1, wherein the current detector is fixed to the output end with the assistance of a robotic arm. A power module comprises: A leadframe-less substrate, which is a composite material layer substrate composed of multiple material layers and does not include a leadframe. The multiple material layers of the leadframe-less substrate include an insulating layer and a first metal layer disposed on the insulating layer by casting and etching, wherein the first metal layer forms a circuit trace disposed on the insulating layer and having an output terminal; At least one semiconductor power device disposed on the circuit trace; A current detector disposed on the output terminal; and A molding compound completely encapsulating the first metal layer of the leadframe-less substrate, the at least one semiconductor power device, and the current detector. The power module is used to convert DC power into AC power, output the AC power through the output terminal, and detect the AC power through the inductive force sensor. The power module as described in claim 5, wherein the magnetic susceptibility of the first metal layer is less than 1 and greater than 0. The power module of claim 5, wherein the leadframe-free substrate further comprises a second metal layer disposed under the insulating layer, and the molding compound partially encapsulates the second metal layer. A power module as described in claim 5, wherein the current detector is fixed to the output end with the assistance of a robotic arm. The power module as described in claim 5 further includes a lead frame connected to the output end. The power module as described in claim 5 further includes a pin structure disposed on the first metal layer, wherein the current detector is a surface-mounted component, and the signal end of the component is electrically connected to the pin structure via the circuit trace. The power module as described in claim 5, wherein the signal terminal of the current detector is electrically connected to the first metal layer via a wiring. The power module as described in claim 5 further includes a multi-layer substrate circuit structure disposed on the first metal layer. In the power module of claim 12, the multi-layer substrate circuit structure extends outside the molding compound, and the signal terminal of the current detector is electrically connected to the multi-layer substrate circuit structure via a wiring. The power module as described in claim 12 further includes a pin structure arranged on the multi-layer substrate circuit structure, and the signal end of the current detector is electrically connected to the multi-layer substrate circuit structure via a wiring, and is electrically connected to the pin structure via the multi-layer substrate circuit structure.