POWER MODULE WITH A LADDER FRAME THAT PROVIDES A SUBSTRATE SUPPORT AND FORMS CONNECTIONS FOR THE POWER MODULE

Abstract

A power module comprises: a conductor frame with a base region and conductors; a plurality of substrates, each having a first metallized side attached to the base region of the conductor frame, a second metallized side opposite the first metallized side, and an insulating body that electrically isolates the first and second metallized sides from each other; at least one semiconductor die attached to the second metallized side of each substrate; and a molding compound that encapsulates the semiconductor dies and part of the conductor frame. The semiconductor dies are electrically interconnected within the power module to form part of a power electronics circuit. The base region of the conductor frame is electrically isolated from the power electronics circuit by the insulating body of the substrates.The ladders of the ladder frame protrude from one or more side surfaces of the molding compound and form connections of the power module.

Description

BACKGROUND

[0001] Molded power modules face several technical challenges, including high material and process costs. A major cost driver for molded power modules is the high-performance ceramics used for insulation and die (chip) attachment processes. Furthermore, inadequate heat dissipation within molded power modules arises due to insufficient space between dies and suboptimal heat dissipation through the ceramic substrates. The ceramic substrates contained in molded power modules are typically exposed at the module backside. The ceramic material is mechanically sensitive and exhibits a high CTE (coefficient of thermal expansion) mismatch when sintered or brazed to an aluminum or copper cooler, causing thermomechanical reliability issues.The mechanical tolerances of molded power modules add up to such an extent that the exposed surface of the ceramic substrates is poorly defined, causing mold flash and variable gaps to the cooler that must be compensated for with a thick interlayer material, such as solder paste. Changes in module functionality (e.g., power output, pin configuration, etc.) require changes to the design and production concept and drive significant investments.

[0002] Therefore, there is a need for an improved molded power module design. SUMMARY

[0003] According to one embodiment of a power module, the power module comprises: a lead frame having a base region and a plurality of leads; a plurality of substrates, each having a first metallized side attached to the base region of the lead frame, a second metallized side opposite the first metallized side, and an insulating body electrically insulating the first and second metallized sides from each other; at least one semiconductor die attached to the second metallized side of each substrate;and a molding compound encapsulating the semiconductor dies and a portion of the lead frame, wherein the semiconductor dies are electrically interconnected within the power module to form a portion of a power electronics circuit, wherein the base region of the lead frame is electrically insulated from the power electronics circuit by the insulating body of the substrates, wherein the leads of the lead frame protrude from one or more side surfaces of the molding compound and form terminals of the power module;

[0004] According to another embodiment of a power module, the power module comprises: a lead frame having a base region and a plurality of conductors; an organic electrically insulating material applied to the base region of the lead frame; a metallization applied to the organic electrically insulating material; a plurality of semiconductor dies attached to the metallization; and a molding compound encapsulating the semiconductor dies and a portion of the lead frame, wherein the semiconductor dies are electrically connected to one another within the power module to form a portion of a power electronics circuit, wherein the base region of the lead frame is electrically insulated from the power electronics circuit by the organic electrically insulating material, wherein the conductors of the lead frame protrude from one or more side surfaces of the molding compound and form terminals of the power module.

[0005] According to one embodiment of a power module, the power module comprises: a lead frame having a base region and a plurality of conductors; a plurality of power semiconductor dies supported by the base region of the lead frame; and a molding compound encapsulating the power semiconductor dies and a portion of the lead frame, wherein the power semiconductor dies are electrically connected to each other within the power module to form part of a power electronic circuit, wherein the base region of the lead frame is electrically insulated from the power semiconductor dies, wherein the conductors of the lead frame protrude from one or more side surfaces of the molding compound and form terminals of the power module.

[0006] Those skilled in the art will recognize additional features and advantages upon reading the following detailed description and upon viewing the accompanying drawings. SHORT DESCRIPTION OF THE CHARACTERS

[0007] The elements of the drawings are not necessarily to scale relative to one another. Like reference numerals indicate corresponding similar parts. The features of the various illustrated embodiments may be combined, provided they are not mutually exclusive. Embodiments are illustrated in the drawings and described in detail in the following description. Fig. 1A illustrates a top perspective view of one embodiment of a molded power module. Fig. Figure 1B illustrates a cross-sectional view of the molded power module along the line shown in Fig. 1A is labeled AA'. Fig. 2A to Fig. 2D illustrate top views of the molded power module used in Fig. 1A and Fig. 1B, during various stages of a manufacturing process. Fig. 3 illustrates a top perspective view of a molded power module according to another embodiment. Fig. 4 illustrates a top perspective view of a molded power module according to another embodiment. Fig. 5 illustrates a top perspective view of a molded power module according to another embodiment. Fig. 6 illustrates a cross-sectional view of a molded power module according to another embodiment. Fig. 7 illustrates a top perspective view of a molded power module according to another embodiment. DETAILED DESCRIPTION

[0008] The embodiments described herein provide a molded power module including a lead frame having a base region for supporting substrates (die carriers) included in the module and leads forming terminals of the power module. The size of the substrates supported by the base region of the lead frame can be minimized because the substrates do not need to be used for power routing, thereby reducing the overall cost of the module. Changes to the module functionality (e.g., power output, pin configuration, etc.) can be made without requiring redesign of the substrates. The molded power module can be single-side cooled or double-side cooled.Instead of substrates (die carriers), an organic electrically insulating material can be applied to the base region of the lead frame with a metallization applied to the organic electrically insulating material. In this example, the semiconductor dies included in the module are attached to the metallization instead of substrates. In both cases (substrates or no substrates), the semiconductor dies included in the module are supported directly (no intermediate substrates) or indirectly (intermediate substrates included) by the base region of the lead frame.

[0009] Next, exemplary embodiments of the molded power module and methods for manufacturing such a molded power module are described with reference to the figures. Each of the molded power module embodiments described herein may be used interchangeably unless expressly stated otherwise.

[0010] Fig. 1A illustrates a top perspective view of one embodiment of a molded power module 100. Fig. Figure 1B illustrates a cross-sectional view of the molded power module 100 along the line shown in Fig. 1A is designated AA'. The molded power module 100 may form part of a power electronics circuit for use in various power applications, such as a DC / AC inverter, a DC / DC converter, an AC / DC converter, a DC / AC converter, an AC / AC converter, a multi-phase inverter, an H-bridge, etc.

[0011] The molded power module 100 includes a lead frame 102 with a base region 104 and leads 106. The lead frame 102 is a metal frame (e.g., copper, copper alloy, iron-nickel alloy, etc.) formed by stamping, punching, etching, etc., and which provides an external electrical connection to the semiconductor dies (chips) 108 included in the molded power module 100 via the leads 106. The base region 104 of the lead frame 102 carries the semiconductor dies 108. In the Fig. 1A and Fig. 1B, the base region 104 of the lead frame 102 supports the semiconductor dies 108 indirectly, since each semiconductor die 108 is attached to a substrate (power electronics carrier) 110. More than one (1) substrate 110 may be included in the molded power module 100, and one or more semiconductor dies 108 may be attached to each substrate 110, e.g., as shown in FIGS. Fig. 1A and Fig. 1B shown.

[0012] Each substrate 110 has a first metallized side 112 attached to the base region 104 of the leadframe 102, a second metallized side 114 opposite the first metallized side 112, and an insulating body 116, such as a ceramic, that electrically isolates the first and second metallized sides 112, 114 from each other. The base region 104 of the leadframe 102 ensures that the substrates 110 are coplanar or nearly coplanar, reducing the overall tolerance of the molded power module 100, which is preferred for molding. A reduced module tolerance ensures lower mold flash and less stress on the substrates 110.

[0013] The substrates 110 can be, for example, DCB (Direct Copper Bonded) substrates, AMB (Active Metal Brazed) substrates, IMS (Insulated Metal Substrate), etc. All substrates 110 can be of the same type, or different types of substrates 110 can be used. For example, one or more of the substrates 110 can be a DCB substrate, and one or more other of the substrates 110 can be an AMB substrate. In this way, different die types (e.g., Si and SiC) can be supported by different types of substrates 110. In another example, all substrates 110 are DCB substrates, AMB substrates, or IMS substrates.

[0014] At least one semiconductor die 108 is attached to the second metallized side 114 of each substrate 110 included in the molded power module 100, e.g., by sintering, soldering, diffusion soldering, brazing, gluing, etc. In contrast to conventional molded power modules, the second metallized side 114 of each substrate 110 may be unstructured (i.e., not patterned) since the substrates 110 are not used for current conduction. Conversely, the substrates included in conventional power modules are patterned to provide current conduction. Accordingly, "islands" of patterned metallization are at different potentials (e.g., DC+, DC-, gate potential, etc.). Fig. 1A and Fig. 1B, the second metallized side 114 of each substrate 110 is unstructured. Accordingly, the entire second metallized side 114 of each substrate 110 is at a single electrical potential, which may be fixed (e.g., ground) or floating. Since the substrates 110 do not provide any current carrying capability, the substrate area can be minimized, significantly reducing substrate costs. This enables high density for chip attachment and reduces the costs of batch processes such as sintering, soldering, etc. The substrates 110 may have the same or different thicknesses.

[0015] A molding compound (plastic) 118 encapsulates the semiconductor dies 108 and a portion of the lead frame 102. The molding compound 118 may include an organic resin such as epoxy resin, a filler such as non-melting inorganic materials, a pigment or dye, a flame retardant, an adhesion promoter, ion traps, a stress reliever, etc.

[0016] As in Fig. 1B, the backside 120 of the base region 104 of the lead frame 102 may be exposed from the molding compound 118 relative to the substrates 110 to provide one-sided cooling of the molded power module 100. In one embodiment, the backside 120 of the base region 104 of the lead frame 102 is electroplated, which protects the backside 120 from environmental damage and color changes and enables sintering / soldering connections. Only the lower part of the molding compound 118 is Fig. 1A to provide an unobstructed view of the module components encapsulated by the molding compound 118.

[0017] The semiconductor dies 108 are electrically connected together within the molded power module 100 to form part of a power electronics circuit, such as an AC-DC rectifier, a DC-AC inverter, a DC-DC converter, and an AC-AC converter, etc. In one embodiment, the semiconductor dies 108 are electrically connected together within the molded power module 100 in a half-bridge or full-bridge configuration.

[0018] In the Fig. 1A and Fig. 1B, the base region 104 of the lead frame 102 is electrically insulated from the power electronics circuitry by the insulating body 116 of the substrates 110. Accordingly, the base region 104 of the lead frame 102 is used only for mechanical support. The leads 106 of the lead frame 102 protrude from one or more side surfaces 122 of the molding compound 118 and form terminals of the molded power module 100. The terminals formed by the leads 106 of the lead frame 102 enable electrical connection of the power electronics circuitry formed by the semiconductor dies 108 included in the molded power module 100 to another electrical device or interface, such as another module, a circuit board, etc.

[0019] The semiconductor dies 108 may be power Si or SiC power MOSFET dies (metal oxide semiconductor field-effect transistor dies), HEMT dies (high electron mobility transistors), IGBT dies (insulated gate bipolar transistors), JFET dies (junction field-effect transistor dies), power diode dies, etc. As shown in the Fig. 1A and Fig. 1B, the semiconductor dies 108 are vertical power transistor dies. For a vertical power transistor die, the primary current flow path is located between the front and back of the die. The drain terminal is typically located on the back of the die, with the gate and source terminals (and optionally one or more sense terminals) located on the front of the die. Additional types of semiconductor dies may be included in the molded power module 100, such as power diode dies, logic dies, control dies, gate driver dies, etc. For the die shown in the Fig. 1A and Fig. In the vertical die example shown in Figure 1B, the drain terminal of each semiconductor die 108 is connected to the second metallized side 114 of the corresponding substrate 110, with the gate and source terminals (and optionally one or more sense terminals) located on the opposite front side of the die 108.

[0020] Subsets of the semiconductor dies 108 may be attached to separate substrates 110, e.g., as shown in the Fig. 1A and Fig. 1B. For example, in the case of a half-bridge power converter configuration, one or more semiconductor dies 108 may be attached to the same substrate 110 or more than one substrate 110 to form the high-side switch of the half-bridge. Likewise, one or more semiconductor dies 108 may be attached to the same substrate 110 or more than one substrate 110 to form the low-side switch of the half-bridge. The number of dies 108 and substrates 110 included in the molded power module 100 depends on several factors, including the type of power electronics circuit implemented using the molded power module 100, the semiconductor die technology (Si and / or SiC and / or GaN, etc.), the substrate technology (DCB and / or AMB and / or IMS, etc.), etc.

[0021] For example, in Fig. 1A, the semiconductor dies 108 attached to the lower row (first group) of substrates 110 may be electrically coupled in parallel to form a low-side switch of a half-bridge, and the semiconductor dies 108 attached to the upper row (second group) of substrates 110 may be electrically coupled in parallel to form a high-side switch of the half-bridge. In this example, a first conductor 106_1 of the lead frame 102 forms a switch node terminal for the molded power module 100, electrically connected to the node between the high-side and low-side switch devices of the half-bridge. The second and third conductors 106_2, 106_3 of the lead frame 102 form a DC+ (high-side) power / phase terminal for the high-side switch device of the half-bridge. A fourth conductor 106_4 of the lead frame 102 forms a DC (low-side) power / phase connection for the low-side switch device of the half-bridge.According to this embodiment, the entire second metallized side 114 of each substrate 100 in the lower row (first group) of substrates 110 is at the switch node potential of the half-bridge and the entire second metallized side 114 of each substrate 110 in the upper row (second group) of substrates 110 is at the DC+ potential of the half-bridge.

[0022] The lead frame 102 may be a single gauge lead frame such that the base region 104 has the same thickness as the leads 106 (T_B = T_L in Fig. 1B). In another embodiment, the leadframe 102 is a two-thickness leadframe, such that the base region 104 is thinner or thicker than the leads 106 (T_B # T_L in Fig. 1B). Separately or in combination, the base region 104 of the lead frame 102 may lie in a first horizontal plane L1 and a distal end 124 of the leads 106 of the lead frame 102 may terminate in a second horizontal plane L2 that is different from the first horizontal plane L1 (e.g., L1 is lower than L2 in Fig. 1B). Separately or in combination, the leadframe 102 may further include one or more tie rods 126 having a proximal end 128 connected to the base region 104 of the leadframe 102 and a severed distal end 130 accessible at a side surface 122 of the molding compound 118. The tie rods 126 stabilize the base region 104 and the leads 106 during the module manufacturing process and are severed after the molding process. The severed distal end 130 of a tie rod 126 may be tested to verify the electrical insulation between the substrates 110 and the base region 104 of the leadframe, e.g., by testing the tie rod 126 or contacting a pin attached to the tie rod 126.

[0023] Internal electrical connections between the module conductors 106 and the semiconductor dies 108 encased in the molding compound 118 may be provided using one or more of wire bonds, wire ribbons, metal clips, a metal frame, etc. For example, in the Fig. 1A and Fig. 1B electrical connections between gate pads 132 of the semiconductor dies 108 and respective structured portions (islands) 134 of the lead frame 102 are provided by bond wires 136. In the Fig. 1A and Fig. 1B, electrical connections between the DC+ power / phase conductors 106_2, 106_3 of the lead frame 102 and the second metallized side 114 of each substrate 110 in the upper row (second group) of substrates 110 are provided by thicker bond wires or ribbons 138. In the Fig. 1A and Fig. 1B, electrical connections between the DC power / phase conductor 106_4 of the lead frame 102 and source pads 140 of the semiconductor dies 108 attached to each substrate 110 in the bottom row (first group) of substrates 110 are provided by thicker bond wires or ribbons 142. In the Fig. 1A and Fig. 1B, thicker bond wires or ribbons 144 provide electrical connections between the second metallized side 114 of each substrate 110 in the bottom row (first group) of substrates 110, source pads 146 of semiconductor dies 108 attached to each substrate 110 in the top row (second group) of substrates 110, and the first conductor 106_1 of the lead frame 102 to provide the half-bridge switch node connection.

[0024] The Fig. 2A to Fig. 2D illustrate top views of the molded power module 100 used in the Fig. 1A and Fig. 1B, during various stages of a manufacturing process.

[0025] Fig. 2A shows the leadframe 102 prior to substrate attachment. The leadframe 102 may be formed from a metal sheet, such as a sheet made of copper, a copper alloy, an iron-nickel alloy, etc. The metal sheet is patterned by stamping, punching, etching, etc., to define the features of the leadframe 102, including the base region 104 and the leads 106. The tie bars 126 anchor the base region 104 and the leads 106 to a peripheral structure 200 of the leadframe 104, which is handled during the fabrication of the molded power module 100.

[0026] Fig. Figure 2B shows the substrates 110 attached to the base region 104 of the lead frame 102. The first metallized side 112 of each substrate 110 can be attached to the base region 104 of the lead frame 102 by sintering, soldering, diffusion soldering, brazing, gluing, etc.

[0027] Fig. Figure 2C shows the electrical connections 136, 138, 142, 144 between the module leads 106 and the semiconductor dies 108. The electrical connections 136, 138, 142, 144 can be formed, for example, by wire bonding and ribbon bonding. The base region 104 and the leads 106 remain anchored to the peripheral structure 200 of the lead frame 104 by the tie bars 126, while the electrical connections 136, 138, 142, 144 are formed.

[0028] Fig. Figure 2D shows the semiconductor dies 108 and a portion of the lead frame 102 encapsulated in the molding compound 118. The molding compound 118 can be formed by injection molding, compression molding, film-assisted molding (FAM), reaction injection molding (RIM), resin transfer molding (RTM), blow molding, etc. Only the lower portion of the molding compound 118 is in Fig. 2D to provide an unobstructed view of the module components encapsulated by the molding compound 118.

[0029] The molded power module 100 then undergoes a trimming and molding process in which each connection point between the peripheral structure 200 of the lead frame 102 and the connecting rods 126, the leads 106, and the base region 104 of the lead frame 102 is separated outside the surface of the molding compound 118. The exposed leads 106 and connecting rods 126 can be plated before or after the peripheral structure 200 is separated.

[0030] Fig. 3 illustrates a top perspective view of a molded power module 300 according to another embodiment. The molded power module 300 in Fig. 3 uses the same lead frame design as the molded power module 100 in the Fig. 1A and Fig. 1B. However, the molded power module 300 in Fig. 3 compared to the molded power module 100 in the Fig. 1A and Fig. 1B has fewer semiconductor dies 100 and fewer substrates 110, e.g., in the case of a lower power module implementation. Despite this difference, the molded power modules 100, 300 have the same footprint. The excess part of the base region 104 of the lead frame 102, which in Fig. 3, resulting from the use of fewer semiconductor dies 100 and substrates 110, may be considered wasteful, but using the same leadframe design to support multiple module configurations (low power, medium power, high power, etc.) avoids costly redesign for each different module configuration. Leadframes are relatively inexpensive compared to other module components, justifying the use of the same leadframe design across different module configurations.

[0031] Fig. 4 illustrates a top perspective view of a molded power module 400 according to another embodiment. The substrates 110 in Fig. 4 include a first group of substrates 110_1 of a first substrate type and a second group of substrates 110_2 of a second substrate type different from the first substrate type. In one embodiment, a first type of semiconductor die 108_1 is attached to the second metallized side 114 of the substrates 110_1 in the first group of substrates 110, and a second type of semiconductor die 108_2, different from the first type of semiconductor die 108_1, is attached to the second metallized side 114 of the substrates 110_2 in the second group of substrates 110. For example, the first substrate type 110_1 may be AMB, the second substrate type 110_2 may be DBC, the first type 108_1 of semiconductor die 108 may be SiC dies, and the second type 108_2 of semiconductor die 108 may be Si dies. In one embodiment, the SiC dies 108_1 are SiC MOSFET dies, and the Si dies 108_2 are Si IGBT dies.SiC dies are more efficient at low load conditions, and IGBT dies are more efficient at high load conditions. A power diode die 402 can be coupled to each Si IGBT die 108_2 to provide a freewheeling current path when the corresponding Si IGBT die 108_2 is off (blocked).

[0032] In another embodiment, the first group of substrates 110_1 and the second group of substrates 110_2 are the same type of substrate (DCB, AMB, IMS, etc.). According to this embodiment, the first type 108_1 of semiconductor die 108 is attached to the second metallized side 114 of the first group of substrates 110_1, and the second (different) type 108_2 of semiconductor die 108 is attached to the second metallized side 114 of the second (same) group of substrates 110_2. Accordingly, different types 108_1, 108_2 of semiconductor die 108 may be attached to the same type of substrate 110 or different types 110_1, 110_2 of substrates 110. In one embodiment, the first group 108_1 of semiconductor dies 108 are power transistor dies, such as power MOSFET dies, HEMT dies, IGBT dies, JFET dies, etc., and the second group 108_2 of semiconductor dies 108 are logic dies and / or control dies configured to drive and / or control the power transistor dies.

[0033] Fig. 5 illustrates a top perspective view of a molded power module 500 according to another embodiment. Fig. 5, the internal electrical connections 136, 138, 142, 144 between the semiconductor dies 108, the substrates 110, and the respective patterned portions 106, 134 of the lead frame 102 are provided by a metal frame 502, such as an additional lead frame or clip frame positioned above or below the first lead frame 102, e.g., by bumps or stamped features on the backside of the metal frame 502, or by solder, electrically conductive adhesive, etc. The metal frame 502 may be formed by stamping, punching, etching, etc., to define the connection features 138, 142, 144 of the metal frame 502.

[0034] Fig. 6 illustrates a cross-sectional view of a molded power module 600 according to another embodiment. The molded power module 600 is similar to the molded power module 100 in FIGS. Fig. 1A and Fig. 1B, but also includes an additional lead frame 602 above or below the first lead frame 102. The molded power module 600 in Fig. 6 also includes additional substrates 604, each having a first metallized side 606 attached to the additional lead frame 602, a second metallized side 608 opposite the first metallized side 606, and an insulating body 610 electrically isolating the first and second metallized sides 606, 608 from each other. The molding compound 118 encapsulates a portion of the additional lead frame 602, and the additional lead frame 602 is electrically isolated from the power electronics circuitry by the insulating body 610 of the additional substrates 604. In one embodiment, the back side 120 of the base region 104 of the first lead frame 102, which faces away from the first substrates 110, is uncovered by the molding compound 118 and the back side 612 of the additional lead frame 602, which faces away from the additional substrates 604, is also uncovered by the molding compound 118, so that the molded power module 600 in Fig. 6 has double-sided cooling. In one embodiment, the backside 120 of the base region 104 of the lead frame 102 and the backside 612 of the additional lead frame 602 are electroplated, which protects both backsides 120, 612 from environmental damage and color changes and enables sintering / soldering connections.

[0035] Fig. Figure 7 illustrates a top perspective view of a molded power module 700 according to another embodiment. The molded power module 700 is similar to the molded power module 100 in Figures Fig. 1A and Fig. 1B. In Fig. 7, the base region 104 of the lead frame 102 carries the semiconductor dies 108 directly by placing the semiconductor dies 108 in Fig. 7 are not attached to a substrate. Instead, an organic electrically insulating material 702 is applied to the base region 104 of the lead frame 102, a metallization 704 is applied to the organic electrically insulating material 702, and the semiconductor dies 108 are attached to the metallization 704. The metallization 704 can be as in Fig. 7 or a single contiguous layer may be structured, depending on the number and arrangement of the semiconductor dies 108.

[0036] In Fig.7, the base region 104 of the lead frame 102 is electrically insulated from the power electronics circuitry by the organic electrically insulating material 702. Accordingly, the base region 104 of the lead frame 102 is used only for mechanical support. In one embodiment, the organic electrically insulating material 702 is an epoxy-based layer, such as an FR-4-based dielectric, and the metallization 704 is a layer of copper laminated to the organic electrically insulating material 702 and having a thickness, e.g., from 35 µm to more than 200 µm. As previously explained herein, one or more of the semiconductor dies 108 may be power transistor dies, and one or more other of the semiconductor dies 108 may be logic dies and / or control dies configured to drive and / or control the power transistor dies.

[0037] Although the present disclosure is not so limited, the following numbered examples illustrate one or more aspects of the disclosure.

[0038] Example 1. A power module comprising: a lead frame having a base region and a plurality of leads; a plurality of substrates, each having a first metallized side attached to the base region of the lead frame, a second metallized side opposite the first metallized side, and an insulating body electrically isolating the first and second metallized sides from each other; at least one semiconductor die attached to the second metallized side of each substrate;and a molding compound encapsulating the semiconductor dies and a portion of the lead frame, wherein the semiconductor dies are electrically interconnected within the power module to form a portion of a power electronics circuit, wherein the base region of the lead frame is electrically insulated from the power electronics circuit by the insulating body of the substrates, wherein the leads of the lead frame protrude from one or more side surfaces of the molding compound and form terminals of the power module;

[0039] Example 2. The power module of Example 1, wherein the second metallized side of each substrate is unstructured.

[0040] Example 3. The power module of example 1 or 2, wherein the entire second metallized side of each substrate is at a single electrical potential.

[0041] Example 4. The power module of any one of examples 1 to 3, wherein the plurality of substrates comprises a first group of substrates of a first substrate type and a second group of substrates of a second substrate type different from the first substrate type.

[0042] Example 5. The power module of example 4, wherein a first type of semiconductor die is attached to the second metallized side of the substrates in the first group of substrates, and wherein a second type of semiconductor die different from the first type of semiconductor die is attached to the second metallized side of the substrates in the second group of substrates.

[0043] Example 6. The power module of example 5, wherein the first substrate type is Active Metal Brazed (AMB), wherein the second substrate type is Direct Bonded Copper (DBC), wherein the first type of semiconductor dies are SiC dies, and wherein the second type of semiconductor dies are Si dies.

[0044] Example 7. The power module of example 6, wherein the SiC dies are SiC MOSFET dies, and wherein the Si dies are Si IGBT dies.

[0045] Example 8. The power module of any one of examples 1 to 7, wherein a first type of semiconductor die is attached to the second metallized side of the substrates in a first group of the substrates, and wherein a second type of semiconductor die different from the first type of semiconductor die is attached to the second metallized side of the substrates in a second group of the substrates.

[0046] Example 9. The power module of Example 8, wherein the substrates in the first group of substrates are a same type of substrate as the substrates in the second group of substrates.

[0047] Example 10. The power module of Example 8, wherein the substrates in the first group of substrates are a different type of substrate than the substrates in the second group of substrates.

[0048] Example 11. The power module of any one of examples 1 to 10, wherein the semiconductor dies within the power module are electrically connected to each other in a half-bridge configuration, wherein the semiconductor dies attached to the second metallized side of the substrates in a first group of the substrates are electrically coupled in parallel to form a low-side switch of the half-bridge, and wherein the semiconductor dies attached to the second metallized side of the substrates in a second group of the substrates are electrically coupled in parallel to form a high-side switch of the half-bridge.

[0049] Example 12. The power module of Example 11, wherein the entire second metallized side of each substrate in the first group of substrates is at a switch node potential of the half-bridge, and wherein the entire second metallized side of each substrate in the second group of substrates is at a DC+ potential of the half-bridge.

[0050] Example 13. The power module of any one of examples 1 to 12, wherein the lead frame is a two-gauge lead frame and the base region is thinner or thicker than the leads.

[0051] Example 14. The power module of any one of examples 1 to 13, wherein the base region of the lead frame lies in a first horizontal plane, and wherein a distal end of the leads of the lead frame terminates in a second horizontal plane different from the first horizontal plane.

[0052] Example 15. The power module of any one of examples 1 to 14, wherein a first group of the semiconductor dies are power transistor dies, and wherein a second group of the semiconductor dies are logic dies and / or control dies configured to drive and / or control the power transistor dies.

[0053] Example 16. The power module of any one of Examples 1 to 15, wherein the lead frame further comprises a connecting rod having a proximal end connected to the base region of the lead frame and a severed distal end accessible at a side surface of the molding compound.

[0054] Example 17. The power module of any one of Examples 1 to 16, further comprising: an additional lead frame above or below the lead frame; and a plurality of additional substrates each having a first metallized side attached to the additional lead frame, a second metallized side opposite the first metallized side, and an insulator electrically isolating the first and second metallized sides from each other, wherein the molding compound encapsulates a portion of the additional lead frame, the additional lead frame being electrically insulated from the power electronic circuitry by the insulator of the additional substrates.

[0055] Example 18. The power module of Example 17, wherein a surface of the base region of the lead frame facing away from the substrates is uncovered by the molding compound and a surface of the additional lead frame facing away from the additional substrates is uncovered by the molding compound, such that the power module has double-sided cooling.

[0056] Example 19. The power module of any one of examples 1 to 18, wherein a side of the base region of the lead frame facing away from the plurality of substrates is electroplated.

[0057] Example 20. A power module comprising: a lead frame having a base region and a plurality of conductors; an organic electrically insulating material applied to the base region of the lead frame; a metallization applied to the organic electrically insulating material; a plurality of semiconductor dies attached to the metallization; and a molding compound encapsulating the semiconductor dies and a portion of the lead frame, wherein the semiconductor dies are electrically connected to each other within the power module to form part of a power electronic circuit, wherein the base region of the lead frame is electrically insulated from the power electronic circuit by the organic electrically insulating material, wherein the conductors of the lead frame protrude from one or more side surfaces of the molding compound and form terminals of the power module.

[0058] Example 21. A power module comprising: a lead frame having a base region and a plurality of leads; a plurality of power semiconductor dies supported by the base region of the lead frame; and a molding compound encapsulating the power semiconductor dies and a portion of the lead frame, wherein the power semiconductor dies are electrically connected to each other within the power module to form part of a power electronic circuit, the base region of the lead frame being electrically insulated from the power semiconductor dies, the leads of the lead frame protruding from one or more side surfaces of the molding compound and forming terminals of the power module.

[0059] Terms such as "first," "second," and the like are used to describe various elements, regions, sections, etc., and are also not intended to be limiting. Like terms refer to like elements throughout the specification.

[0060] As used herein, the terms "having," "containing," "including," "comprising," and the like are open-ended terms that indicate the presence of specified elements or features but do not preclude additional elements or features. The articles "a," "an," and "the" are intended to include both the plural and singular unless the context clearly indicates otherwise.

[0061] The phrase "and / or" should be interpreted to include all possible conjunctive and disjunctive combinations, unless explicitly stated otherwise. For example, the phrase "A and / or B" should be interpreted to mean only A, only B, or both A and B. The phrase "at least one of" should be interpreted in the same way as "and / or" unless explicitly stated otherwise. For example, the phrase "at least one of A and B" should be interpreted to mean only A, only B, or both A and B.

[0062] It is understood that the features of the various embodiments described herein may be combined with one another unless expressly stated otherwise.

[0063] Although specific embodiments have been illustrated and described herein, those skilled in the art will recognize that a variety of alternative and / or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this invention be limited only by the claims and their equivalents.

Claims

[1] Power module (100, 300, 400, 500, 600, 700), comprising: a lead frame (102) having a base region (104) and a plurality of leads (106, 106_2, 106_3); a plurality of substrates (110, 110_1, 110_2), each having a first metallized side (112, 606) attached to the base region (104) of the lead frame (102), a second metallized side (114, 608) opposite the first metallized side (112, 606), and an insulating body (116, 610) electrically insulating the first and second metallized sides (114, 608) from one another; at least one semiconductor die attached to the second metallized side (114, 608) of each substrate (110, 110_1, 110_2); and a molding compound (118) encapsulating the semiconductor dies (108, 108_1, 108_2) and a portion of the lead frame (102), wherein the semiconductor dies (108, 108_1, 108_2) within the power module (100, 300, 400, 500, 600, 700) are electrically connected to one another to form part of a power electronics circuit, wherein the base region (104) of the lead frame (102) is electrically insulated from the power electronics circuit by the insulating body (116, 610) of the substrates (110, 110_1, 110_2), wherein the conductors (106, 106_2, 106_3) of the lead frame protrude from one or more side surfaces (122) of the molding compound (118) and form terminals of the power module (100, 300, 400, 500, 600, 700). [2] The power module (100, 300, 400, 500, 600, 700) of claim 1, wherein the second metallized side (114, 608) of each substrate (110, 110_1, 110_2) is unstructured. [3] Power module (100, 300, 400, 500, 600, 700) according to claim 1 or 2, wherein the entire second metallized side (114, 608) of each substrate (110, 110_1, 110_2) is at a single electrical potential. [4] Power module (100, 300, 400, 500, 600, 700) according to one of the preceding claims, wherein the plurality of substrates (110, 110_1, 110_2) comprises a first group of substrates (110_1) of a first substrate type and a second group of substrates (110_2) of a second substrate type different from the first substrate type. [5] The power module (100, 300, 400, 500, 600, 700) of claim 4, wherein a first type of semiconductor die (108_1) is attached to the second metallized side (114, 608) of the substrates (110, 110_1, 110_2) in the first group of substrates (110_1), and wherein a second type of semiconductor die (108_2) different from the first type of semiconductor die (108_1) is attached to the second metallized side (114, 608) of the substrates (110, 110_1, 110_2) in the second group of substrates (110_2). [6] The power module (100, 300, 400, 500, 600, 700) of claim 5, wherein the first substrate type is Active Metal Brazed (AMB), wherein the second substrate type is Direct Bonded Copper (DBC), wherein the first type of semiconductor dies (108_1) are SiC dies, and wherein the second type of semiconductor dies (108_2) are Si dies. [7] Power module (100, 300, 400, 500, 600, 700) according to one of the preceding claims, wherein a side of the base region (104) of the lead frame (102) facing away from the plurality of substrates (110, 110_1, 110_2) is electroplated. [8] The power module (100, 300, 400, 500, 600, 700) of any preceding claim, wherein a first type of semiconductor die (108_1) is mounted on the second metallized side (114, 608) of the substrates (110, 110_1, 110_2) in a first group of the substrates (110_1), and wherein a second type of semiconductor die (108_2) different from the first type of semiconductor die (108_1) is mounted on the second metallized side (114, 608) of the substrates (110, 110_1, 110_2) in a second group of the substrates (110_2). [9] The power module (100, 300, 400, 500, 600, 700) according to claim 8, wherein the substrates (110, 110_1, 110_2) in the first group of substrates (110_1) are a same type of substrate (110, 110_1, 110_2) as the substrates (110_2) in the second group of substrates (110, 110_1, 110_2). [10] The power module (100, 300, 400, 500, 600, 700) according to claim 8, wherein the substrates (110_1) in the first group of substrates (110, 110_1, 110_2) are a different type of substrate (110, 110_1, 110_2) than the substrates (110_2) in the second group of substrates (110, 110_1, 110_2). [11] Power module (100, 300, 400, 500, 600, 700) according to one of the preceding claims, wherein the semiconductor dies (108, 108_1, 108_2) within the power module (100, 300, 400, 500, 600, 700) are electrically connected to one another in a half-bridge configuration, wherein the semiconductor dies (108, 108_1, 108_2) attached to the second metallized side (114, 608) of the substrates (110_1) in a first group of the substrates (110, 110_1, 110_2) are electrically coupled in parallel to form a low-side switch of the half-bridge, and wherein the semiconductor dies (108, 108_1, 108_2) attached to the second metallized side (114, 608) of the substrates (110_2) in a second group of substrates (110, 110_1, 110_2) are electrically coupled in parallel to form a high-side switch of the half-bridge. [12] The power module (100, 300, 400, 500, 600, 700) of claim 11, wherein the entire second metallized side (114, 608) of each substrate (110_1) in the first group of substrates (110, 110_1, 110_2) is at a switch node potential of the half-bridge, and wherein the entire second metallized side (114, 608) of each substrate (110_2) in the second group of substrates (110, 110_1, 110_2) is at a DC+ potential of the half-bridge. [13] Power module (100, 300, 400, 500, 600, 700) according to one of the preceding claims, wherein the lead frame (102) is a two-thickness lead frame and the base region (104) is thinner or thicker than the leads (106, 106_2, 106_3). [14] Power module (100, 300, 400, 500, 600, 700) according to one of the preceding claims, wherein the base region (104) of the lead frame (102) lies in a first horizontal plane, and wherein a distal end (124) of the leads (106, 106_2, 106_3) of the lead frame terminates in a second horizontal plane different from the first horizontal plane. [15] The power module (100, 300, 400, 500, 600, 700) of claim 1, wherein a first group of the semiconductor dies (108_1) are power transistor dies, and wherein a second group of the semiconductor dies (108_2) are logic dies and / or control dies configured to drive and / or control the power transistor dies. [16] The power module (100, 300, 400, 500, 600, 700) of any preceding claim, wherein the lead frame (102) further comprises a connecting rod (126) having a proximal end (128) connected to the base portion (104) of the lead frame (102) and a severed distal end (130) accessible at a side surface (122) of the molding compound (118). [17] Power module (100, 300, 400, 500, 600, 700) according to one of the preceding claims, further comprising: an additional lead frame (602) above or below the lead frame (102); and a plurality of additional substrates (604), each having a first metallized side (112, 606) attached to the additional lead frame (602), a second metallized side (114, 608) opposite the first metallized side (112, 606), and an insulating body (116, 610) electrically insulating the first and second metallized sides (114, 608) from each other, wherein the molding compound (118) encapsulates a portion of the additional lead frame (602), wherein the additional lead frame (602) is electrically insulated from the power electronics circuit by the insulating body (116, 610) of the additional substrates (604). [18] The power module (100, 300, 400, 500, 600, 700) according to claim 17, wherein a surface of the base region (104) of the lead frame (102) facing away from the substrates (110, 110_1, 110_2) is uncovered by the molding compound (118) and a surface of the additional lead frame (602) facing away from the additional substrates (604) is uncovered by the molding compound (118), so that the power module (100, 300, 400, 500, 600, 700) has double-sided cooling. [19] Power module (100, 300, 400, 500, 600, 700), comprising: a lead frame (102) having a base region (104) and a plurality of leads (106, 106_2, 106_3); an organic electrically insulating material (702) applied to the base region (104) of the lead frame (102); a metallization (704) applied to the organic electrically insulating material (702); a plurality of semiconductor dies (108, 108_1, 108_2) attached to the metallization (704); and a molding compound (118) encapsulating the semiconductor dies (108, 108_1, 108_2) and a portion of the lead frame (102), wherein the semiconductor dies (108, 108_1, 108_2) within the power module (100, 300, 400, 500, 600, 700) are electrically connected to one another to form part of a power electronics circuit, wherein the base region (104) of the lead frame (102) is electrically insulated from the power electronics circuit by the organic electrically insulating material (702), wherein the conductors (106, 106_2, 106_3) of the lead frame protrude from one or more side surfaces (122) of the molding compound (118) and form terminals of the power module (100, 300, 400, 500, 600, 700). [20] Power module (100, 300, 400, 500, 600, 700), comprising: a lead frame (102) having a base region (104) and a plurality of leads (106, 106_2, 106_3); a plurality of power semiconductor dies supported by the base region (104) of the lead frame (102); and a molding compound (118) encapsulating the power semiconductor dies and a portion of the lead frame (102), wherein the power semiconductor dies within the power module (100, 300, 400, 500, 600, 700) are electrically connected to each other to form part of a power electronics circuit, wherein the base region (104) of the lead frame (102) is electrically insulated from the power semiconductor dies, wherein the conductors (106, 106_2, 106_3) of the lead frame protrude from one or more side surfaces (122) of the molding compound (118) and form terminals of the power module (100, 300, 400, 500, 600, 700).

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