Power module with lead frame providing substrate support and forming terminals of power module
The substrate and semiconductor die are supported by the lead frame and encapsulated with molded compounds, the high cost and insufficient heat dissipation of the molded power module are solved, achieving higher thermal mechanical reliability and lower production costs.
Patent Information
- Application Number
- CN202411047748.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-08-08
- Filing Date
- 2024-08-01
- Publication Date
- 2025-02-18
AI Technical Summary
Molded power modules face high costs, insufficient heat dissipation and thermal mechanical reliability problems, mainly due to the use of high-performance ceramic materials and the design limitations of ceramic substrates.
The lead frame supports the substrate and semiconductor die, and the die is molded into a compound to encapsulate the die and part of the lead frame, thereby achieving electrical interconnection and mechanical support, reducing the use of the substrate and improving the heat dissipation effect.
Reduces the overall cost of the module, improves heat dissipation efficiency, reduces mechanical tolerances and molded burrs, and enhances thermal mechanical reliability.
Smart Images
Figure CN119480832A_ABST
Abstract
Description
Background Art
[0001] Molded power modules face a number of technical challenges, including high material and process costs. The main cost driver for molded power modules is the high-performance ceramics used for isolation and die (chip) attachment processes. In addition, due to the insufficient space between the dies and the suboptimal heat dissipation through the ceramic substrate, insufficient heat dissipation occurs in the molded power module. The ceramic substrate included in the molded power module is usually exposed at the back side of the module. Ceramic materials are mechanically fragile and have a high CTE (thermal expansion coefficient) mismatch when sintered or soldered to an aluminum or copper cooler, causing thermomechanical reliability issues. The mechanical tolerance of the molded power module increases, so that the exposed surface of the ceramic substrate is not clearly defined, resulting in molded burrs and variable gaps between the cooler that must be compensated by thick interlayer materials (such as solder paste). Changing module functions (e.g., power output, pin configuration, etc.) requires changing design and production concepts and requires huge investments.
[0002] Therefore, there is a need for an improved molded power module design. Summary of the invention
[0003] According to an embodiment of a power module, the power module includes: a lead frame having a base region and a plurality of leads; a plurality of substrates, each of the plurality of substrates having a first metallization side attached to the base region of the lead frame, a second metallization side opposite to the first metallization side, and an insulator electrically isolating the first metallization side from the second metallization side; at least one semiconductor die attached to the second metallization side of each substrate; and a molding compound encapsulating the semiconductor die and a portion of the lead frame, wherein the semiconductor die are electrically interconnected within the power module to form a portion of a power electronic circuit, wherein the base region of the lead frame is electrically isolated from the power electronic circuit by the insulator of the substrate, wherein the leads of the lead frame extend from one or more sides of the molding compound and form terminals of the power module.
[0004] According to another embodiment of a power module, the power module includes: a lead frame having a base region and a plurality of leads; 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 interconnected within the power module to form a portion of a power electronic circuit, wherein the base region of the lead frame is electrically isolated from the power electronic circuit by the organic electrically insulating material, wherein the leads of the lead frame extend from one or more sides of the molding compound and form terminals of the power module.
[0005] According to an embodiment of a power module, the power module includes: 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 interconnected within the power module to form a portion of a power electronic circuit, wherein the base region of the lead frame is electrically isolated from the power semiconductor dies, and wherein the leads of the lead frame extend from one or more sides 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. BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The elements in the drawings are not necessarily to scale with respect to each other. The same reference numerals refer to corresponding identical parts. Unless the features of the various illustrated embodiments are mutually exclusive, they may be combined. The embodiments are depicted in the drawings and described in detail in the following description.
[0008] Figure 1A A top perspective view of an embodiment of a molded power module is shown.
[0009] Figure 1B shows the molded power module along Figure 1A A cross-sectional view along the line marked AA' in FIG.
[0010] FIG. 2A to FIG. 2D Shows Figure 1A and Figure 1B 00100] Figure 2 is a top plan view of a molded power module shown in FIG. 1 during different stages of the manufacturing method.
[0011] Figure 3 A top perspective view of a molded power module according to another embodiment is shown.
[0012] Figure 4 A top perspective view of a molded power module according to another embodiment is shown.
[0013] Figure 5 A top perspective view of a molded power module according to another embodiment is shown.
[0014] Figure 6 A cross-sectional view of a molded power module according to another embodiment is shown.
[0015] Figure 7 A top perspective view of a molded power module according to another embodiment is shown. DETAILED DESCRIPTION
[0016] Embodiments described herein provide a molded power module, which includes a lead frame having a base region for supporting a substrate (die carrier) included in the module and leads forming terminals of the power module. Since the substrate does not need to be used for current routing, the size of the substrate supported by the base region of the lead frame can be minimized, thereby reducing the overall cost of the module. Changes can be made to module functions (e.g., power output, pin configuration, etc.) without redesigning the substrate. The molded power module can be single-sided cooling or double-sided cooling. An organic electrical insulating material can be applied to the base region of the lead frame instead of the substrate (die carrier), wherein the metallization is applied to the organic electrical insulating material. In this example, the semiconductor die included in the module is attached to the metallization, rather than the substrate. In either case (with or without a substrate), the semiconductor die included in the module is directly supported (without an intermediate substrate) or indirectly supported (including an intermediate substrate) by the base region of the lead frame.
[0017] Described next with reference to the accompanying drawings are exemplary embodiments of a molded power module and a method of producing such a molded power module. Unless explicitly stated otherwise, any molded power module embodiments described herein may be used interchangeably.
[0018] Figure 1A A top perspective view of an embodiment of a molded power module 100 is shown. Figure 1B The molded power module 100 is shown along Figure 1A The molded power module 100 may form part of a power electronic circuit for various power applications, such as for DC / AC inverters, DC / DC converters, AC / DC converters, DC / AC converters, AC / AC converters, multi-phase inverters, H-bridges, etc.
[0019] The molded power module 100 includes a lead frame 102 having 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 providing external electrical connections to a semiconductor die (chip) 108 included in the molded power module 100 via the leads 106. The base region 104 of the lead frame 102 supports the semiconductor die 108. Figure 1A and Figure 1B In the embodiment, since each semiconductor die 108 is attached to a substrate (power electronic carrier) 110, the base region 104 of the lead frame 102 indirectly supports the semiconductor die 108. For example, Figure 1A and Figure 1B As shown in , more than one 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 .
[0020] Each substrate 110 has a first metallized side 112 attached to the base region 104 of the lead frame 102, a second metallized side 114 opposite the first metallized side 112, and an insulator 116 (e.g., ceramic) electrically isolating the first metallized side 112 and the second metallized side 114 from each other. The base region 104 of the lead frame 102 ensures that the substrate 110 is coplanar or nearly coplanar, thereby reducing the overall tolerance of the molded power module 100, which is beneficial for molding. The reduced module tolerance ensures less molded flash and lower stress on the substrate 110.
[0021] The substrate 110 may be, for example, a DCB (direct copper bonding) substrate, an AMB (active metal brazing) substrate, an IMS (insulated metal substrate), etc. All substrates 110 may be of the same type, or different types of substrates 110 may be used. For example, one or more of the substrates 110 may be a DCB substrate, and one or more other substrates of the substrates 110 may be an AMB substrate. In this way, different types of substrates 110 may support different die types (e.g., Si and SiC). In another example, all substrates 110 are DCB substrates, AMB substrates, or IMS substrates.
[0022] At least one semiconductor die 108 is attached to the second metallization side 114 of each substrate 110 included in the molded power module 100, for example by sintering, welding, diffusion welding, brazing, gluing, etc. Unlike conventional molded power modules, since the substrate 110 is not used for current wiring, the second metallization side 114 of each substrate 110 may not be patterned (i.e., unpatterned). In contrast, the substrates included in conventional power modules are patterned to provide current wiring. Therefore, the "islands" of the patterned metallization are at different potentials (e.g., DC+, DC-, gate potential, etc.). Figure 1A and Figure 1B In the embodiment, the second metallization side 114 of each substrate 110 is not patterned. Therefore, the entire second metallization side 114 of each substrate 110 is at a single potential, which can be fixed (e.g., grounded) or floating. In addition, since the substrate 110 does not provide current routing, the substrate area can be reduced to a minimum, which significantly reduces the substrate cost. This enables high-density die attachment and reduces the cost of batch processing (e.g., sintering, welding, etc.). The substrates 110 can have the same or different thicknesses.
[0023] Molding compound (plastic) 118 encapsulates semiconductor die 108 and a portion of lead frame 102. Molding compound 118 may include an organic resin (e.g., epoxy), a filler (e.g., a non-melting inorganic material, a pigment or colorant, a flame retardant, an adhesion promoter, an ion trapping agent, a stress relief agent, etc.).
[0024] like Figure 1B As shown, the back side 120 of the base region 104 of the lead frame 102 opposite the substrate 110 can be exposed from the mold compound 118, thereby providing single-sided cooling for the molded power module 100. In one embodiment, the back side 120 of the base region 104 of the lead frame 102 is plated, which protects the back side 120 from environmental damage and color change and allows for sinter / solder connections. In order to provide an unobstructed view of the module components encapsulated by the mold compound 118, Figure 1A Only the lower portion of the mold compound 118 is shown.
[0025] The semiconductor dies 108 are electrically interconnected within the molded power module 100 to form a portion of a power electronic circuit (e.g., an AC to DC rectifier, a DC to AC inverter, a DC to DC converter, and an AC to AC converter, etc.) In one embodiment, the semiconductor dies 108 are electrically interconnected within the molded power module 100 in a half-bridge or full-bridge configuration.
[0026] exist Figure 1A and Figure 1B1 , the base region 104 of the lead frame 102 is electrically isolated from the power electronic circuit by the insulator 116 of the substrate 110. Therefore, the base region 104 of the lead frame 102 is used only for mechanical support. The leads 106 of the lead frame 102 extend from one or more sides 122 of the mold 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 electronic circuit formed by the semiconductor die 108 included in the molded power module 100 with another electrical device or interface (e.g., another module, a printed circuit board, etc.).
[0027] The semiconductor die 108 may be a power Si or SiC power MOSFET (metal oxide semiconductor field effect transistor) die, a HEMT (high electron mobility transistor) die, an IGBT (insulated gate bipolar transistor) die, a JFET (junction field effect transistor) die, a power diode die, etc. Figure 1A and Figure 1B As shown, semiconductor die 108 is a vertical power transistor die. For a vertical power transistor die, the main current flow path is between the front side and the back side of the die. The drain terminal is typically located at the back side of the die, with the gate terminal and the source terminal (and optionally, one or more sense terminals) located at the front side of the die. Other types of semiconductor dies may be included in the molded power module 100, such as power diode dies, logic dies, controller dies, gate driver dies, etc. Figure 1A and Figure 1B In the vertical die example shown in , the drain terminal of each semiconductor die 108 is connected to the second metallization side 114 of the corresponding substrate 110 , with the gate terminal and the source terminal (and optionally, one or more sense terminals) located at opposite front sides of the die 108 .
[0028] For example, Figure 1A and Figure 1B As shown, a subset of semiconductor dies 108 can be attached to separate substrates 110. For example, in the case of a half-bridge power converter configuration, one or more semiconductor dies 108 can be attached to the same substrate 110 or more than one substrate 110 to form a high-side switch of the half-bridge. Similarly, one or more semiconductor dies 108 can be attached to the same substrate 110 or more than one substrate 110 to form a 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 electronic circuit implemented using the molded power module 100, semiconductor die technology (Si and / or SiC and / or GaN, etc.), substrate technology (DCB and / or AMB and / or IMS, etc.), etc.
[0029] For example, in Figure 1A In the embodiment of the present invention, the semiconductor die 108 attached to the next row (first group) substrate 110 can be electrically coupled in parallel to form a low-side switch of a half bridge, and the semiconductor die 108 attached to the previous row (second group) substrate 110 can be electrically coupled in parallel to form a high-side switch of a half bridge. In this example, the first lead 106_1 of the lead frame 102 forms a switch node terminal for the molded power module 100, which is electrically connected to a node between the high-side switch device and the low-side switch device of the half bridge. The second lead 106_2 and the third lead 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. The fourth lead 106_4 of the lead frame 102 forms a DC- (low-side) power / phase terminal for the low-side switch device of the half bridge. According to this embodiment, the entire second metallization side 114 of each substrate 100 in the next row (first group) of substrates 110 is at the switch node potential of the half bridge, and the entire second metallization side 114 of each substrate 110 in the previous row (second group) of substrates 110 is at the DC+ potential of the half bridge.
[0030] Lead frame 102 may be a single gauge lead frame such that base region 104 has the same thickness as leads 106 (in Figure 1B In another embodiment, the lead frame 102 is a double-gauge lead frame, so that the base region 104 is thinner than the lead 106, or thicker than the lead 106 (in Figure 1B , T_B≠T_L). Individually or in combination, the base region 104 of the lead frame 102 may be located in a first horizontal plane L1, and the distal ends 124 of the leads 106 of the lead frame 102 may terminate in a second horizontal plane L2 different from the first horizontal plane L1 (e.g., Figure 1B , L1 is lower than L2). Either alone or in combination, the lead frame 102 may also include one or more connecting bars 126 having a proximal end 128 connected to the base region 104 of the lead frame 102, and a cut distal end 130 accessible at the side 122 of the molding compound 118. The connecting bars 126 stabilize the base region 104 and the leads 106 during the module manufacturing process, and are cut after the molding process. The cut distal ends 130 of the connecting bars 126 may be tested, for example, by probing the connecting bars 126 or contacting the pins attached to the connecting bars 126 to verify electrical isolation between the substrate 110 and the base region 104 of the lead frame.
[0031] Internal electrical connections between module leads 106 and semiconductor die 108 enclosed in mold compound 118 may be provided by using one or more of wire bonds, wire straps, metal clamps, metal frames, etc. For example, in Figure 1A and Figure 1B In FIG. 1 , electrical connection between gate pad 132 of semiconductor die 108 and corresponding patterned portion (island) 134 of lead frame 102 is provided by bonding wire 136. Figure 1A and Figure 1B In FIG. 1 , the electrical connection between the DC+ power / phase leads 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 is provided by a thicker bonding wire or ribbon 138. Figure 1A and Figure 1B In , the electrical connection between the DC-power / phase lead 106_4 of the lead frame 102 and the source pad 140 of the semiconductor die 108 attached to each substrate 110 in the next row (first group) of substrates 110 is provided by a thicker bonding wire or ribbon 142. Figure 1A and Figure 1B In the figure, a thicker bonding wire or ribbon 144 provides an electrical connection between the second metallization side 114 of each substrate 110 in the next row (first group) of substrates 110, the source pad 146 of the semiconductor die 108 attached to each substrate 110 in the previous row (second group) of substrates 110, and the first lead 106_1 of the lead frame 102 to provide a half-bridge switch node connection.
[0032] FIG. 2A to FIG. 2D Shows Figure 1A and Figure 1B 1 is a top plan view of a molded power module 100 during different stages of the manufacturing method.
[0033] Figure 2A The lead frame 102 is shown before substrate attachment. The lead frame 102 may be formed from a metal sheet (e.g., 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 lead frame 102, including the base region 104 and the leads 106. The tie bars 126 anchor the base region 104 and the leads 106 to the peripheral structure 200 of the lead frame 104, which is processed during the manufacture of the molded power module 100.
[0034] Figure 2B Substrates 110 are shown attached to base region 104 of lead frame 102. A first metallized side 112 of each substrate 110 may be attached to base region 104 of lead frame 102 by sintering, welding, diffusion welding, soldering, gluing, or the like.
[0035] Figure 2CElectrical connections 136, 138, 142, 144 between module leads 106 and semiconductor die 108 are shown. For example, electrical connections 136, 138, 142, 144 can be formed by wire bonding and ribbon bonding. While forming electrical connections 136, 138, 142, 144, base region 104 and leads 106 remain anchored to peripheral structure 200 of lead frame 104 by tie bars 126.
[0036] Figure 2D The semiconductor die 108 and a portion of the lead frame 102 are shown encapsulated in a mold compound 118. The mold compound 118 may be formed by injection molding, compression molding, film assisted molding (FAM), reaction injection molding (RIM), resin transfer molding (RTM), blow molding, etc. In order to provide an unobstructed view of the module components encapsulated by the mold compound 118, Figure 2D Only the lower portion of the mold compound 118 is shown.
[0037] The molded power module 100 is then subjected to a trimming and forming process during which each connection point between the peripheral structure 200 of the lead frame 102 and the connecting bars 126, the leads 106, and the base region 104 of the lead frame 102 is cut outside the allowable range of the molding compound 118. The exposed leads 106 and connecting bars 126 may be plated before or after the peripheral structure 200 is cut.
[0038] Figure 3 A top perspective view of a molded power module 300 is shown according to another embodiment. Figure 3 The molded power module 300 in the embodiment uses the Figure 1A and Figure 1B However, for example, in the case of the lower power module embodiment, the lead frame design of the molded power module 100 is the same as that of the molded power module 100 in FIG. Figure 1A and Figure 1B Compared with the molded power module 100, Figure 3 The molded power module 300 in FIG. 1 has fewer semiconductor dies 100 and fewer substrates 110. Despite this difference, the molded power modules 100 and 300 have the same footprint. Figure 3 In the embodiment of the present invention, the excess portion of the base area 104 of the lead frame 102 caused by using fewer semiconductor dies 100 and substrates 110 may be considered wasteful, but using the same lead frame design to support multiple module configurations (low power, medium power, high power, etc.) avoids expensive redesigns for each different module configuration. Compared to other module components, lead frames are relatively inexpensive, thus justifying the use of the same lead frame design in different module configurations.
[0039] Figure 4 A top perspective view of a molded power module 400 is shown according to another embodiment. Figure 4 The substrate 110 in the embodiment includes 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, the second substrate type being different from the first substrate type. In one embodiment, a first type of semiconductor die 108_1 is attached to a second metallization side 114 of the substrate 110_1 in the first group of substrates 110, and a second type of semiconductor die 108_2 is attached to a second metallization side 114 of the substrate 110_2 in the second group of substrates 110, the second type of semiconductor die 108_2 being different from the first type of semiconductor die 108_1. For example, the first substrate type 110_1 may be an AMB, the second substrate type 110_2 may be a DBC, the semiconductor die 108 of the first type 108_1 may be a SiC die, and the semiconductor die 108 of the second type 108_2 may be a Si die. In one embodiment, the SiC die 108_1 is a SiC MOSFET die, and the Si die 108_2 is a Si IGBT die. SiC dies are more efficient under low load conditions, and IGBT dies are more efficient under high load conditions.A power diode die 402 may be coupled to each Si IGBT die 108_2 to provide a freewheeling current path when the corresponding Si IGBT die 108_2 is turned off (blocked).
[0040] In another embodiment, the first group of substrates 110_1 and the second group of substrates 110_2 are the same type of substrates (DCB, AMB, IMS, etc.). According to this embodiment, the semiconductor die 108 of the first type 108_1 is attached to the second metallization side 114 of the first group of substrates 110_1, and the semiconductor die 108 of the second (different) type 108_2 is attached to the second metallization side 114 of the second (same type) group of substrates 110_2. Therefore, the different types 108_1, 108_2 of semiconductor die 108 can be attached to the same type of substrate 110 or substrates 110 of different types 110_1, 110_2. In one embodiment, the first group 108_1 semiconductor die 108 are power transistor dies, such as power MOSFET dies, HEMT dies, IGBT dies, JFET dies, etc., and the second group 108_2 semiconductor die 108 are logic dies and / or controller dies configured to drive and / or control the power transistor dies.
[0041] Figure 5 A top perspective view of a molded power module 500 according to another embodiment is shown. Figure 5In the embodiment, the internal electrical connections 136, 138, 142, 144 between the semiconductor die 108, the substrate 110, and the corresponding patterned portions 106, 134 of the lead frame 102 are provided by a metal frame 502 (e.g., an additional lead frame or a fixture frame located above or below the first lead frame 102), for example, by bumps or stamped features at the back side of the metal frame 502, or by solder, conductive adhesive, etc. The metal frame 502 can be formed by stamping, punching, etching, etc. to define the interconnection features 138, 142, 144 of the metal frame 502.
[0042] Figure 6 FIG. 4 is a cross-sectional view of a molded power module 600 according to another embodiment. Figure 1A and Figure 1B The molded power module 100 is similar to the molded power module 100 in FIG. 1 , but further includes an additional lead frame 602 located above or below the first lead frame 102 . Figure 6 The molded power module 600 in the embodiment further includes an additional substrate 604, each of the additional substrates 604 having a first metallization side 606 attached to the additional lead frame 602, a second metallization side 608 opposite the first metallization side 606, and an insulator 610 electrically isolating the first metallization side 606 and the second metallization side 608 from each other. The mold compound 118 encapsulates a portion of the additional lead frame 602, and the additional lead frame 602 is electrically isolated from the power electronic circuit by the insulator 610 of the additional substrate 604. In one embodiment, the back side 120 of the base region 104 of the first lead frame 102 facing away from the first substrate 110 is not covered by the mold compound 118, and the back side 612 of the additional lead frame 602 facing away from the additional substrate 604 is not covered by the mold compound 118, so that Figure 6 The molded power module 600 in has double-sided cooling. In one embodiment, the back side 120 of the base region 104 of the lead frame 102 and the back side 612 of the additional lead frame 602 are plated, which protects both back sides 120, 612 from environmental damage and color change and allows for sinter / solder connections.
[0043] Figure 7 FIG. 8 is a top perspective view of a molded power module 700 according to another embodiment. Figure 1A and Figure 1B The molded power module 100 is similar to that in FIG. Figure 7 In the embodiment, the base region 104 of the lead frame 102 directly supports the semiconductor die 108 because Figure 7In the embodiment, the semiconductor die 108 is not attached to the 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 die 108 is attached to the metallization 704. Figure 7 The metallization 704 may be patterned as shown, or may be a single continuous layer, depending on the number and arrangement of semiconductor dies 108 .
[0044] exist Figure 7 , the base region 104 of the lead frame 102 is electrically isolated from the power electronic circuit by the organic electrical insulating material 702. Therefore, the base region 104 of the lead frame 102 is only used for mechanical support. In one embodiment, the organic electrical insulating material 702 is an epoxy-based layer, such as an FR-4-based dielectric, and the metallization 704 is a copper layer laminated on the organic electrical insulating material 702 and having a thickness of, for example, 35 μm to greater than 200 μm. As previously explained herein, one or more of the semiconductor dies 108 can be power transistor dies, and one or more other of the semiconductor dies 108 can be logic dies and / or controller dies configured to drive and / or control the power transistor dies.
[0045] Although the present disclosure is not limited in this regard, the following numbered examples demonstrate one or more aspects of the present disclosure.
[0046] Example 1: A power module comprises: a lead frame having a base region and a plurality of leads; a plurality of substrates, each of the plurality of substrates having a first metallization side attached to the base region of the lead frame, a second metallization side opposite the first metallization side, and an insulator electrically isolating the first metallization side from the second metallization side; at least one semiconductor die attached to the second metallization side of each substrate; and a molding compound encapsulating the semiconductor die and a portion of the lead frame, wherein the semiconductor die are electrically interconnected within the power module to form a portion of a power electronic circuit, wherein the base region of the lead frame is electrically isolated from the power electronic circuit by the insulator of the substrate, and wherein the leads of the lead frame extend from one or more sides of the molding compound and form terminals of the power module.
[0047] Example 2: The power module of Example 1, wherein the second metallization side of each substrate is unpatterned.
[0048] Example 3: The power module of Example 1 or 2, wherein the entire second metallization side of each substrate is at a single potential.
[0049] Example 4: The power module of any of Examples 1 to 3, wherein the plurality of substrates includes a first group of substrates of a first substrate type and a second group of substrates of a second substrate type, the second substrate type being different from the first substrate type.
[0050] Example 5: A power module according to Example 4, wherein a first type of semiconductor die is attached to a second metallization side of a substrate in a first group of substrates, and wherein a second type of semiconductor die is attached to a second metallization side of a substrate in a second group of substrates, the second type of semiconductor die being different from the first type of semiconductor die.
[0051] Example 6: A power module according to Example 5, wherein the first substrate type is active metal brazing (AMB), wherein the second substrate type is direct bonded copper (DBC), wherein the first type of semiconductor die is a SiC die, and wherein the second type of semiconductor die is a Si die.
[0052] Example 7: The power module of Example 6, wherein the SiC die is a SiC MOSFET die, and wherein the Si die is a Si IGBT die.
[0053] Example 8: A power module according to any one of Examples 1 to 7, wherein a first type of semiconductor die is attached to a second metallization side of a substrate in a first group of substrates, and wherein a second type of semiconductor die is attached to a second metallization side of a substrate in a second group of substrates, the second type of semiconductor die being different from the first type of semiconductor die.
[0054] Example 9: The power module of Example 8, wherein the substrates in the first group of substrates and the substrates in the second group of substrates are the same type of substrates.
[0055] Example 10: The power module according to Example 8, wherein the substrates in the first group of substrates and the substrates in the second group of substrates are different types of substrates.
[0056] Example 11: A power module according to any one of Examples 1 to 10, wherein semiconductor die are electrically interconnected in a half-bridge configuration within the power module, wherein semiconductor die attached to a second metallization side of a substrate in a first group of substrates are electrically coupled in parallel to form a low-side switch of the half-bridge, and wherein semiconductor die attached to a second metallization side of a substrate in a second group of substrates are electrically coupled in parallel to form a high-side switch of the half-bridge.
[0057] Example 12: The power module of Example 11, wherein the entire second metallization side of each substrate in the first group of substrates is at the switch node potential of the half bridge, and wherein the entire second metallization side of each substrate in the second group of substrates is at the DC+ potential of the half bridge.
[0058] Example 13: The power module of any of Examples 1 to 12, wherein the lead frame is a dual gauge lead frame, and the base region is thinner than the leads, or thicker than the leads.
[0059] Example 14: The power module of any of Examples 1 to 13, wherein a base region of the lead frame is located in a first horizontal plane, and wherein distal ends of the leads of the lead frame terminate in a second horizontal plane different from the first horizontal plane.
[0060] Example 15: A power module according to any one of Examples 1 to 14, wherein the first group of semiconductor dies are power transistor dies, and wherein the second group of semiconductor dies are logic dies and / or controller dies configured to drive and / or control the power transistor dies.
[0061] Example 16: The power module of any of Examples 1 to 15, wherein the lead frame further comprises a tie bar having a proximal end connected to a base region of the lead frame and a severed distal end accessible at a side of the molding compound.
[0062] Example 17: A power module according to any one of Examples 1 to 16, further comprising: an additional lead frame located above or below the lead frame; and a plurality of additional substrates, each of the plurality of additional substrates having a first metallization side attached to the additional lead frame, a second metallization side opposite to the first metallization side, and an insulator electrically isolating the first metallization side and the second metallization side from each other, wherein a molding compound encapsulates a portion of the additional lead frame, wherein the additional lead frame is electrically isolated from the power electronic circuit by the insulator of the additional substrate.
[0063] Example 18: The power module of Example 17, wherein a surface of the base region of the lead frame facing away from the substrate is not covered by the molding compound, and a surface of the additional lead frame facing away from the additional substrate is not covered by the molding compound, such that the power module has double-sided cooling.
[0064] Example 19: The power module of any of Examples 1 to 18, wherein a side of the base region of the lead frame facing away from the plurality of substrates is plated.
[0065] Example 20: A power module comprises: a lead frame having a base region and a plurality of leads; 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 interconnected within the power module to form a portion of a power electronic circuit, wherein the base region of the lead frame is electrically isolated from the power electronic circuit by the organic electrically insulating material, and wherein the leads of the lead frame extend from one or more sides of the molding compound and form terminals of the power module.
[0066] Example 21: A power module comprises: 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 interconnected within the power module to form a portion of a power electronic circuit, wherein the base region of the lead frame is electrically isolated from the power semiconductor dies, and wherein the leads of the lead frame extend from one or more sides of the molding compound and form terminals of the power module.
[0067] Terms such as "first", "second", etc. are used to describe various elements, regions, parts, etc., and are not intended to be limiting. Throughout the specification, the same terms refer to the same elements.
[0068] As used herein, the terms "having," "containing," "including," "comprising," and the like are open-ended terms that indicate the presence of stated elements or features, but do not exclude additional elements or features. Unless the context clearly indicates otherwise, the articles "a," "an," and "the" are intended to include the plural as well as the singular.
[0069] Unless otherwise expressly stated, the expression "and / or" should be interpreted as including all possible conjoint and disjoint combinations. For example, the expression "and / or" should be interpreted as meaning only A, only B, or both A and B. Unless otherwise expressly stated, the expression "at least one of..." should be interpreted in the same way as "and / or". For example, the expression "at least one of A and B" should be interpreted as meaning only A, only B, or both A and B.
[0070] It should be understood that the features of the various embodiments described herein may be combined with each other, unless specifically stated otherwise.
[0071] Although specific embodiments have been shown and described herein, it will be appreciated by those of ordinary skill in the art that various alternative and / or equivalent embodiments may be substituted for the specific embodiments shown and described without departing from the scope of the invention. This application is intended to cover any adjustments or modifications to the specific embodiments discussed herein. Therefore, it is intended that the present invention be limited only by the claims and their equivalents.
Claims
1. A power module, comprising: a lead frame having a base region and a plurality of leads; a plurality of substrates, each of the plurality of substrates 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 insulator electrically isolating the first metallized side from the second metallized side; at least one semiconductor die attached to the second metallization side of each substrate; as well as a molding compound encapsulating the semiconductor die and a portion of the lead frame, wherein the semiconductor dies are electrically interconnected within the power module to form a part of a power electronic circuit, wherein the base region of the lead frame is electrically isolated from the power electronic circuit by the insulator of the substrate, The leads of the lead frame extend from one or more sides of the molding compound and form terminals of the power module.
2. The power module according to claim 1, wherein: The second metallized side of each substrate is unpatterned.
3. The power module according to claim 1, wherein: The entire second metallization side of each substrate is at a single potential.
4. The power module according to claim 1, wherein: The plurality of substrates includes a first group of substrates of a first substrate type and a second group of substrates of a second substrate type that is different from the first substrate type.
5. The power module according to claim 4, wherein: A first type of semiconductor die is attached to the second metallized side of the substrate in the first group of substrates, and wherein a second type of semiconductor die is attached to the second metallized side of the substrate in the second group of substrates, the second type of semiconductor die being different from the first type of semiconductor die.
6. The power module according to claim 5, wherein: The first substrate type is active metal brazing (AMB), wherein the second substrate type is direct bonded copper (DBC), wherein the first type of semiconductor die is a SiC die, and wherein the second type of semiconductor die is a Si die.
7. The power module according to claim 1, wherein: A side of the base region of the lead frame facing away from the plurality of substrates is plated.
8. The power module according to claim 1, wherein: A first type of semiconductor die is attached to the second metallized side of the substrate in the first group of substrates, and wherein a second type of semiconductor die is attached to the second metallized side of the substrate in the second group of substrates, the second type of semiconductor die being different from the first type of semiconductor die.
9. The power module according to claim 8, wherein: The substrates in the first group of substrates and the substrates in the second group of substrates are the same type of substrates.
10. The power module according to claim 8, wherein: The substrates in the first group of substrates and the substrates in the second group of substrates are different types of substrates.
11. The power module according to claim 1, wherein: The semiconductor dies are electrically interconnected in a half-bridge configuration within the power module, wherein the semiconductor dies attached to the second metallization side of the substrate in a first group of 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 metallization side of the substrate in a second group of substrates are electrically coupled in parallel to form a high-side switch of the half-bridge.
12. The power module according to claim 11, wherein: The entire second metallization 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 metallization side of each substrate in the second group of substrates is at a DC+ potential of the half bridge.
13. The power module according to claim 1, wherein: The lead frame is a double gauge lead frame, and the base region is thinner than the leads, or thicker than the leads.
14. The power module according to claim 1, wherein: The base region of the lead frame is located in a first horizontal plane, and wherein distal ends of the leads of the lead frame terminate in a second horizontal plane different from the first horizontal plane.
15. The power module according to claim 1, 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 controller dies configured to drive and / or control the power transistor dies.
16. The power module according to claim 1, wherein: The lead frame further includes a tie bar having a proximal end connected to the base region of the lead frame and a severed distal end accessible at a side of the molding compound.
17. The power module according to claim 1, further comprising: an additional lead frame, the additional lead frame being located above or below the lead frame; as well as a plurality of additional substrates, each of the plurality of additional substrates 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 metallized side and the second metallized side from each other, wherein the molding compound encapsulates a portion of the additional lead frame, Wherein, the additional lead frame is electrically isolated from the power electronic circuit by the insulator of the additional substrate.
18. The power module according to claim 17, wherein: A surface of the base region of the lead frame facing away from the substrate is not covered by the molding compound, and a surface of the additional lead frame facing away from the additional substrate is not covered by the molding compound, so that the power module has double-sided cooling.
19. A power module, comprising: a lead frame having a base region and a plurality of leads; 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; as well as a molding compound encapsulating the semiconductor die and a portion of the lead frame, wherein the semiconductor dies are electrically interconnected within the power module to form a part of a power electronic circuit, wherein the base region of the lead frame is electrically isolated from the power electronic circuit by the organic electrical insulating material, The leads of the lead frame extend from one or more sides of the molding compound and form terminals of the power module.
20. 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; as well as a molding compound encapsulating the power semiconductor die and a portion of the lead frame, wherein the power semiconductor dies are electrically interconnected within the power module to form a part of a power electronic circuit, wherein the base region of the lead frame is electrically isolated from the power semiconductor die, The leads of the lead frame extend from one or more sides of the molding compound and form terminals of the power module.