A power module having an overmolded component, an apparatus including such a power module, and a method for manufacturing a power module having an overmolded component.

Abstract

The power module has: electrical connections, preferably made of metal, each electrical connection having a motherboard extending substantially coplanar in the same main plane, at least one electrical connection including at least one electrical connector projecting from its motherboard; at least one transistor electrically connected between two upper surfaces of two respective motherboards; and an electrically insulating overmolding (402), for example made of resin, covering at least a portion of the upper surfaces of each transistor and motherboard. At least one of the electrical connections also has at least one attachment tenon (322) for attachment to the overmolding (402), wherein if the electrical connection includes one or more electrical connectors, the attachment tenon is separate from the one or more electrical connectors of the electrical connection, each attachment tenon (322) projecting from the edge of the motherboard of the electrical connection only in one projection direction (DP) in the main plane, and the overmolding (402) at least partially covers the attachment tenon (322).

Description

Technical Field

[0001] The present invention relates to a power module having an overmolded part, an electronic system having such a power module and a voltage converter, and to a method for manufacturing such a power module having an overmolded part. Background Technology

[0002] French patent application publication number FR 3 068 564 A1 describes a power module having:

[0003] The electrical connection, preferably made of metal, has a main board extending in the same main plane and thus substantially coplanar, and at least one of the electrical connections includes at least one electrical connector protruding from its main board.

[0004] At least one transistor is electrically connected between the two upper surfaces of the two motherboards, respectively; and

[0005] Electrically insulating overmolded components, such as overmolded components made of resin, cover at least a portion of the upper surface of each transistor and motherboard.

[0006] For example, this power module can be used in motor vehicles. However, in such an environment, the power module may be subjected to relatively large mechanical vibrations.

[0007] The disadvantage of this power module is that, over time, the overmolded part is at risk of detaching, for example, due to the mechanical vibrations mentioned above.

[0008] Therefore, it may be desirable to provide a power module that can alleviate at least some of the aforementioned problems and limitations. Summary of the Invention

[0009] Therefore, a power module is proposed, which has:

[0010] - Electrical connection parts, preferably made of metal, each electrical connection part having a main board that extends in the same main plane to be substantially coplanar, at least one electrical connection part including at least one electrical connector protruding from its main board.

[0011] - At least one transistor, electrically connected between the two upper surfaces of the two corresponding motherboards; and

[0012] - Electrically insulating encapsulated moldings, for example made of resin, covering at least a portion of the upper surface of each transistor and the motherboard;

[0013] The feature is that at least one electrical connection portion further has at least one attachment tenon for attachment to an overmolded part, wherein if the electrical connection portion includes an electrical connector (one or more), the attachment tenon is separate from the electrical connector of the electrical connection portion, each attachment tenon protrudes from the edge surface of the main board of the electrical connection portion only in one projection direction of the main plane, and the overmolded part at least partially covers the attachment tenon.

[0014] According to the present invention, compared with the case without the attachment tenon, the contact surface area between the overmolded part and the connecting part is increased, thereby enabling the main board to be better held by the overmolded part.

[0015] The power module according to the invention may further include one or more of the following optional features, which may be used individually or in any technically feasible combination.

[0016] According to the first feature, the electrical connector protrudes from the motherboard in the main plane.

[0017] According to another feature, the transistor has a lower face that is held against the upper face of one of the motherboards to which the transistor is connected.

[0018] According to another feature, the attachment tenon and the main plate supporting the attachment tenon are made of a single piece of continuous material.

[0019] According to another feature, the electrical connector and the motherboard carrying the electrical connector are made of a single continuous material.

[0020] According to another feature, the power module has two transistors, which, for example, have lower surfaces that are held against the upper surfaces of two different connecting components or against the upper surfaces of the same connecting component.

[0021] According to another feature, at least one electrical connector protrudes at least partially in the main plane.

[0022] According to another feature, each electrical connection includes at least one electrical connector protruding from its main board.

[0023] According to another characteristic, overmolded parts are single, one-piece components.

[0024] According to another feature, on the one hand, each transistor has a lower surface abutting against one of the two upper surfaces that are electrically connected to the transistor, and on the other hand, each transistor is electrically connected to the other of the two upper surfaces, for example, through one or more conductive strips or wires.

[0025] According to another feature, at least one motherboard has at least one first cavity filled by an overmolding member on its lower surface, and in the cavity, the overmolding member has a lower surface flush with the lower surface of the motherboard.

[0026] According to another feature, each first cavity has an opening on the edge surface of the motherboard having the cavity.

[0027] According to another feature, each electrical connector has a fixed end that is fixed to the motherboard, and the fixed end has a lower surface that is not covered by the overmolded part.

[0028] According to another feature, the overmolded part has a downwardly projecting pad.

[0029] According to another feature, the motherboards are separated from each other in the main plane by at least one gap, the overlay molding fills each gap and has a lower surface in each gap that is flush with the lower surface of the motherboard.

[0030] According to another feature, the liner protrudes from the lower surface of the overmolded part present in the gap.

[0031] According to another feature, the protruding direction of the attachment tenon is substantially perpendicular to the edge surface of the main board, and the attachment tenon protrudes from this edge surface.

[0032] According to another feature, the length of the attachment tenon in its projecting direction is less than or equal to 5 mm.

[0033] According to another feature, the electrical connection is obtained by cutting from a metal plate.

[0034] According to another feature, the attachment tenon is formed from fastening lug residue, which is formed by cutting in the fastening lug, before the cutting connects the main plate to another plate coplanar with the metal plate.

[0035] According to another feature, the attachment tenon is located on the outer edge surface portion of the main board.

[0036] According to another feature, each of the at least one attachment tenon has a thickness and a width greater than or equal to its thickness.

[0037] According to another feature, the attachment tenon is completely covered by the overmolded part.

[0038] According to another feature, each attachment tenon has:

[0039] The mounting end is fixed to the edge surface of the motherboard.

[0040] upper surface,

[0041] lower face,

[0042] Two lateral surfaces, and

[0043] front,

[0044] Furthermore, the overmolded part shall at least partially cover one or more of the following: the lower face, upper face, side face, and front face of each attachment tenon.

[0045] According to another feature, the overmolded part is such that the lower surface of at least one attachment tenon is at least partially uncovered.

[0046] According to another feature, the overmolded part has at least one second cavity, such that the upper surface of at least one attachment tenon is at least partially uncovered.

[0047] According to another feature, the cavity defines a free space that surrounds a straight cylinder with a circular bottom in the main plane, the diameter of which is between 3 mm and 5 mm, preferably 4 mm, and the center is located at a distance of 0.5 mm to 1.5 mm, preferably 1 mm, from a connecting line on the main plane that connects two portions of the edge surface of the molded part surrounding the cavity.

[0048] According to another feature, the center of the round bottom is vertically positioned relative to the middle of the width of the attached tenon.

[0049] According to another feature, the overmolded part has a peripheral protrusion that at least partially borders the outer edge of the overmolded part in the main plane and protrudes downward beyond the lower face of the main body (one or more), the peripheral protrusion at least partially covering the lower face of at least one of the attachment tenons (one or more).

[0050] According to another feature, the peripheral protrusion covers the front of the fixed end of the attachment tenon so that the lower surface of the attachment tenon is not covered at its fixed end.

[0051] According to another feature, the front face of at least one attachment tenon is completely covered by the overmolding member, for example, by the peripheral protrusion of the overmolding member, and the lower face of the attachment tenon is covered by the peripheral protrusion.

[0052] According to another feature, the front of at least one attachment tenon is completely covered by the overmolded part.

[0053] According to another feature, at least one attachment tenon protrudes in its projection direction by a distance of less than 2 mm beyond the covering molded part.

[0054] According to another feature, the power module has two attachment protrusions protruding from the edge surface of the same motherboard, and on the one hand, the overmolding at least partially covers a portion of the edge surface extending between the two attachment protrusions, and on the other hand, the overmolding at least partially covers the opposing lateral surfaces of the two attachment protrusions.

[0055] According to another feature, the overmolded part makes at least a portion of the lower surface of the motherboard with at least one electrical connection visible, and the visible portion is designed to be held against the heat sink.

[0056] According to another feature, the transistor is held against the motherboard, a portion of the lower surface of which is visible through an overlay molding, so that the transistor is held against the heat sink.

[0057] An electronic system is also proposed, comprising a heat sink and a power module according to the invention, wherein the heat sink is in thermal contact with at least one lower surface visible through an overmolded part.

[0058] According to optional features, the heat sink is in thermal contact with at least a portion of the lower surface visible through the overmolded part via an electrically insulating thermal connection element.

[0059] According to another optional feature, the pad contacts the heat sink to control the thickness of the electrically insulating thermal connection element between the heat sink and the lower surface (one or more) of the motherboard (one or more) not covered by the overmolded part.

[0060] A voltage converter is also proposed, comprising a power module according to the invention or an electronic system according to the invention.

[0061] A method for manufacturing power modules is also proposed, comprising the following steps:

[0062] A conductive plate extending in the main plane is obtained, the conductive plate preferably being made of metal;

[0063] Cut from the conductive plate: on the one hand, a frame portion and a plurality of planar portions having at least two electrical connection portions, each electrical connection portion having a main board that extends in a main plane to be substantially coplanar, at least one electrical connection portion including at least one electrical connector protruding from its main board; and on the other hand, fastening lugs for fastening each main board to at least one other component.

[0064] At least one transistor is electrically connected between the two upper surfaces of the two corresponding motherboards;

[0065] A molding die for at least a portion of the upper surface of a transistor or motherboard is manufactured using an electrically insulating material, such as resin; and

[0066] Cut the fastening lugs to separate each electrical connection from the others;

[0067] The feature is that the fastening lug is cut to leave a fastening lug residue, the fastening lug residue protruding from one of the main boards and forming an attachment tenon for attachment to an overlay molding protruding from the main board in the main plane, and if the electrical connection includes an electrical connector, the attachment tenon is separate from the electrical connector of the electrical connection, each attachment tenon protruding from the edge surface of the main board of the electrical connection only in one projection direction in the main plane, and the overlay molding is made to at least partially cover the attachment tenon.

[0068] The method according to the invention may also have one or more of the following optional features, which may be used individually or in any technically possible combination.

[0069] According to the first characteristic, overmolded parts are made by casting or injection molding electrical insulating material into a mold in one step.

[0070] According to another feature, the overmolded part is made before the fastening lug is cut.

[0071] According to another feature, the overmolded part is made after the fastening lugs are cut.

[0072] According to another feature, cutting the fastening lug includes cutting a first portion of the fastening lug, then manufacturing an overmolded part, and then cutting a second portion of the fastening lug.

[0073] According to another feature, the manufacture of the overmolded part includes manufacturing a portion of the overmolded part, then cutting and fastening lugs, and then manufacturing a second portion of the overmolded part.

[0074] According to another feature, the overmolded part is made to have at least one cavity, such that the upper surface of at least one attachment tenon is at least partially uncovered.

[0075] According to another feature, the cavity defines a free space that surrounds a straight cylinder with a circular bottom in the main plane, the diameter of which is between 3 mm and 5 mm, preferably 4 mm, and the center is located at a distance of between 0.5 mm and 1.5 mm, preferably 1 mm, from a connecting line of the main plane that connects two portions of the edge surface of the molded part surrounding the cavity.

[0076] According to another feature, the cutting of the fastening lug includes first placing the reinforcing member against the upper surface of at least one fastening lug, which is not covered by the cavity, and then cutting the fastening lug 2104 from bottom to top with a cutting tool, thereby producing a shearing effect through the reinforcing member. Attached Figure Description

[0077] The invention will be better understood through the following description, provided by way of example only, with reference to the accompanying drawings, in which:

[0078] Figure 1 An electrical system having a voltage converter implementing the present invention is illustrated schematically;

[0079] Figure 2 yes Figure 1 A three-dimensional exploded view of the voltage converter.

[0080] Figure 3 yes Figure 2 A three-dimensional top view of the power module of the voltage converter, without the encapsulation molding.

[0081] Figure 4 It is similar to Figure 3 View, with covering molded parts,

[0082] Figure 5 yes Figure 3 and 4 A three-dimensional bottom view of the power module, without the overlay molding.

[0083] Figure 6 It is similar to Figure 5 View, with covering molded parts,

[0084] Figure 7 It is used to attach to Figures 3 to 6 A three-dimensional top view of the attachment tenon on the encasing mold of the power module, without the encasing mold.

[0085] Figure 8 It is similar to Figure 7 View, with covering molded parts,

[0086] Figure 9 yes Figure 7 and Figure 8 A three-dimensional bottom view of the attachment tenon, with the covering molded part.

[0087] Figure 10 This is a top view of the cavity covering the molded part, which does not cover the upper surface of the attached tenon.

[0088] Figure 11 This is a three-dimensional bottom view of the attachment tenon in the alternative embodiment.

[0089] Figure 12 yes Figure 11 A three-dimensional cross-sectional view of the power module in an alternative embodiment.

[0090] Figure 13 This is a three-dimensional bottom view of the attachment tenon in the alternative embodiment.

[0091] Figure 14 yes Figure 13 A three-dimensional cross-sectional view of the power module in an alternative embodiment.

[0092] Figure 15 This is a three-dimensional bottom view of the attachment tenon in the alternative embodiment.

[0093] Figure 16 yes Figure 15 A three-dimensional cross-sectional view of the power module in an alternative embodiment.

[0094] Figure 17 This is a three-dimensional bottom view of the attachment tenon in the alternative embodiment.

[0095] Figure 18 yes Figure 17 A three-dimensional cross-sectional view of the power module in an alternative embodiment.

[0096] Figure 19 yes Figure 1 A three-dimensional view of another embodiment of the power module of the voltage converter, without the encapsulation molding.

[0097] Figure 20 It is similar to Figure 19 View, with covering molded parts,

[0098] Figure 21 This is a three-dimensional bottom view of a plate that has been cut to form the electrical connection parts of a power module, including the overlay molding.

[0099] Figure 22 yes Figure 21 A three-dimensional top view of the cutting plate, and

[0100] Figure 23 The sequential steps of a method for manufacturing a power module according to an embodiment of the present invention are shown. Detailed Implementation

[0101] Now refer to Figure 1 An electrical system 100 for implementing the present invention is described.

[0102] For example, electrical system 100 is used for installation in motor vehicles.

[0103] The electrical system 100 first has a power supply 102, which is designed to supply a DC voltage U, for example, a DC voltage between 10V and 100V, such as 48V or 12V. The power supply 102 may have a battery, for example.

[0104] In addition, the electrical system 100 has a motor 130, which has multiple phases (not shown) and these phases are intended to have corresponding phase voltages.

[0105] In addition, the electrical system 100 has a voltage converter 104 connected between the power supply 102 and the motor 130 to perform the conversion between DC voltage U and phase voltage.

[0106] The voltage converter 104 first has a positive bus 106 and a negative bus 108 for connecting to the power supply 102 to receive DC voltage U, the positive bus 106 receiving a high potential and the negative bus 108 receiving a low potential.

[0107] In addition, the voltage converter 104 has at least one power module 110, which has one or more phase buses 122 for connecting to one or more phases of the motor 130 respectively to supply their respective phase voltages.

[0108] In the described example, the voltage converter 104 has three power modules 110, each power module having a two-phase bus 122 connected to two phases of the motor 130.

[0109] More specifically, in the described example, motor 130 has two three-phase systems, each with three phases and intended to be electrically phase-shifted by 120° relative to each other. Preferably, the first phase bus 122 of power module 110 is connected to the three phases of the first three-phase system, and the second phase bus 122 of power module 110 is connected to the three phases of the second three-phase system.

[0110] For each phase bus 122, each power module 110 includes a high-side switch 112 connected between the positive bus 106 and the phase bus 122, and a low-side switch 114 connected between the phase bus 122 and the negative bus 108. Thus, switches 112 and 114 are arranged to form switch arms, wherein the phase bus 122 forms a center tap.

[0111] Each switch 112, 114 includes first and second main terminals 116, 118 and a control terminal 120 for selectively opening and closing the switch 112, 114 between its two main terminals 116, 118 according to a control signal applied thereto. Switches 112, 114 are preferably transistors, such as metal-oxide-semiconductor field-effect transistors (MOSFETs), with their gate forming the control terminal 120 and their drain and source forming the main terminals 116, 118, respectively. Alternatively, switches 112, 114 may be insulated-gate bipolar transistors (IGBTs).

[0112] In the described example, switches 112 and 114 are each in the form of a plate, which is substantially rectangular, for example, and has an upper surface and a lower surface. A first main terminal 116 extends on the lower surface, while a second main terminal 118 extends on the upper surface. Switches 112 and 114 are used to allow a current greater than 1A to flow between their main terminals 116 and 118.

[0113] It will be understood that the positive busbar 106, negative busbar 108, and phase busbar 122 are rigid electrical conductors designed to withstand a current of at least 1 A intended to flow through switches 112 and 114. They preferably have a thickness of at least 1 mm.

[0114] Furthermore, in the described example, the positive bus 106 first has a positive common bus 106A connecting the power modules 110, and in each power module 110, there is a positive local bus 106B connected to the positive common bus 106A. Similarly, the negative bus 108 has a negative common bus 108A connecting the power modules 110, and in each power module 110, there is a negative local bus 108B for each low-side switch 114, the negative local bus 108B being connected to the negative common bus 108B. These connections are in... Figure 1 It is displayed as a rhombus.

[0115] Furthermore, in the described example, both the positive common bus 106A and the negative common bus 108A are formed from a single conductive component.

[0116] Furthermore, in the described example, motor 130 operates as both an alternator and an electric motor. More specifically, the vehicle also has an internal combustion engine (not shown) with an output shaft to which motor 130 is connected via a belt (not shown). The internal combustion engine is used to drive the vehicle wheels through its output shaft. Therefore, when operating as an alternator, motor 130 supplies electrical energy to power source 102 from the rotation of its output shaft. Voltage converter 104 then operates as a rectifier. When operating as an electric motor, the motor drives the output shaft (in addition to, or in place of, the internal combustion engine). Voltage converter 104 then operates as an inverter.

[0117] The motor 130 may be located, for example, in the gearbox or clutch of a motor vehicle, or in place of an alternator.

[0118] In the remainder of the specification, the structure and layout of the components of the voltage converter 104 will be described in more detail with reference to the vertical direction HB, where “H” indicates the top and “B” indicates the bottom.

[0119] Reference Figure 2 The voltage converter 104 includes a heat sink 206 with a heat exchange surface 204, and a power module 110. Figure 2 The diagram shows a single power module 110 mounted on a heat exchange surface 204. Heat is exchanged between the heat exchange surface 204 of the heat sink 206 and the power module 110, for example, through direct contact or contact via thermal paste between the heat exchange surface 204 of the heat sink 206 and the power module 110.

[0120] The voltage converter 104 also includes a support housing 208, on which, for example, the auxiliary electronic module of the control module 210 is fixed. Figure 1 In the example, control module 210 is a control board. Alternatively, support housing 208 is mounted on heat sink 206.

[0121] Reference Figure 3 The power module 110 has a plurality of electrical connections 304, which are preferably made of metal.

[0122] Each electrical connection 304 has a main plate 306 extending in a horizontal main plane PP, and all main plates 306 are such that they are substantially coplanar. Specifically, in the described example, the main plate 306 has a corresponding horizontal upper surface 308 extending at the same height. For clarity, Figure 3 Only the upper part 308 of the largest motherboard 306 is shown.

[0123] Furthermore, the motherboards 306 are separated from each other in the main plane PP by at least one gap 310. In the described example, the width of each gap 310 is less than or equal to 5 mm. This means that the two motherboards defining the gap 310 are separated by a maximum of 5 mm along the gap 310.

[0124] Generally, at least one (in the described example, all) electrical connection portion 304 also has at least one electrical connector protruding from its main board 306. For example, each electrical connector may be in the form of a pin 3121, or a folded tab 3122, 3123, or a straight tab 3124.

[0125] In the example described herein, the straight tab 3124 forms the phase busbar 122, the folded tab 3123 forms the local busbar 106A, and the folded tab 3122 forms the negative local busbar 108B.

[0126] In the first two cases, each electrical connector 3121, 3122, and 3123 has: a fixed end 314 fixed to the motherboard 306; a main portion 316 extending vertically and terminating at a free end 318 in the above example; and an elbow 320 connecting the fixed end 314 to the main portion 316. For clarity, these various elements of the electrical connectors 3121, 3122, and 3123 are... Figure 3Only two electrical connectors, 3121 and 3122, are shown in the image; one is in the form of a pin, and the other is in the form of a tab.

[0127] In the case of a straight tab, the electrical connector 3124 protrudes a considerable length from the main plane PP, for example, at least one centimeter, thereby allowing it to be connected. Furthermore, the electrical connector 3124 has a retaining end 314 that is fixed to the main board 306, and this retaining end 314 has a considerable width, for example, at least one centimeter, to allow current to pass through.

[0128] In addition, at least one of the electrical connection portions 304 also has at least one attachment tenon 322 for attachment to the cover molding of the power module 110, which will be referred to below. Figure 4 The following description is provided. In the described example, a plurality of attachment protrusions 322 are provided. The attachment protrusions 322 are used to abut the overmolded part against the electrical connection portion 304. The attachment protrusions 322(one or more) of the electrical connection portion 304 are thus separated from the electrical connectors(one or more) 3121, 3122, 3123 and 3124 that may be present on the electrical connection portion 304. In particular, due to its design, such as due to its size, each attachment protrusion 322 cannot establish an electrical connection with other electrical conductors, and is therefore used to maintain no electrical connection with other electrical conductors.

[0129] Therefore, each attachment tenon 322 protrudes from the edge surface of the main board 306 of the electrical connection 304 only in one projection direction DP on the main plane PP. This contrasts with the pin-type electrical connector 3121 and the folded tab-type electrical connectors 3122, 3123, which have vertically projecting vertical portions 316. For example, the projection direction DP of the attachment tenon 322 is substantially perpendicular to the edge surface of the main board 306, from which the attachment tenon 322 protrudes. The length of the attachment tenon 322 in its projection direction DP is preferably less than or equal to 5 mm, its thickness E is the same as the thickness of the main board 306 in the example, and its width L is greater than or equal to its thickness E. This width L is preferably less than or equal to 5 mm. These dimensions contrast with the dimensions of the straight tab-type electrical connector 3124.

[0130] Preferably, the attachment tenon 322 is located on the outside of the power module 110. Therefore, each attachment tenon 322 is located on the outer edge surface portion of the motherboard 306, that is, it does not define the edge surface portion of the gap 310.

[0131] As will refer to Figures 21 to 23As explained in detail, in this example, the electrical connection 304 is obtained by cutting from a metal plate. Therefore, each attachment tenon 322 can be formed from a fastening lug residue, which is formed by cutting into a fastening lug that connects the main plate to another plate coplanar with the metal plate before cutting.

[0132] In the example described here, the metal plate is made of copper. As a variation, the metal plate could be made of aluminum or gold.

[0133] Furthermore, as described above, the power module 110 has transistors 112 and 114, each electrically connected between two upper surfaces 308 of two corresponding main boards 306, for example, to allow power current (e.g., greater than 1 ampere) to pass through and be interrupted between the two main boards 306 as needed. Each transistor 112 and 114 first has a lower surface held against one of the two upper surfaces 308, which is electrically connected to both upper surfaces. Additionally, each transistor 112 and 114 has an upper surface, a portion of which is electrically connected to the other of the two upper surfaces, for example via one or more conductive strips 326 (as shown in the example) or wires. In the described example, the upper surface of transistors 112 and 114 also has a control portion for controlling transistors 112 and 114, which is electrically connected to the upper surface of a third main board 306, for example via wire 328 in the described example.

[0134] In the described example, the conductive strip 326 is made of aluminum and has dimensions of, for example, 2 mm × 0.3 mm. In a variant embodiment, the conductive strip 326 is made of gold.

[0135] In the described example, wire 328 is made of aluminum and has a diameter of 0.2 mm. In a variant embodiment, wire 328 is made of gold.

[0136] In the described example, the pin-type electrical connector 3121 is used to connect the power module 110 to the control module 210 to measure electrical variables and control transistors 112, 114.

[0137] Furthermore, still in the described example, electrical connector 3122 is connected to negative bus 108, and electrical connector 3123 is connected to positive bus 106.

[0138] Furthermore, still in the described example, two electrical connectors 3124 in the form of straight tabs form two phase buses 122 of the power module 110, respectively.

[0139] Reference Figure 4The diagram shows an overmolded portion of the power module 110, labeled with reference numeral 402. The overmolded portion 402 is an electrical insulator and completely covers at least a portion of each transistor 112, 114, each conductive strip 326, and each wire 328, as well as the upper surface 308 of the main board 306. The overmolded portion 402 is made of resin, for example, and in a further example, epoxy resin. Preferably, the overmolded portion 402 is a one-piece component.

[0140] The overmolding 402 at least partially covers each attachment tenon 322. Compared to the case without tenons, the contact surface area between the overmolding 402 and the connecting portion 304 is increased, thereby allowing the main plate 306 to be better held by the overmolding 402.

[0141] Reference Figure 5 At least one main board 306 has at least one cavity 504 on its lower surface 502 for retaining the overmolded part 402. Each retaining cavity 504 opens on an edge surface of the main board 306 having the cavity. In other words, the retaining cavity 504 is located at the outer periphery of the lower surface 502 of the main board 306. Furthermore, each retaining cavity 504 defines a vertically offset horizontal step at the top of the lower surface 502 of the main board 306. For example, each retaining cavity 504 is formed by stamping.

[0142] like Figure 6 As shown, the overmolding 402 makes at least a portion of the lower surface 502 of the main board 306, which includes at least one electrical connector 3121, 3122, 3123, 3124, for each electrical connection portion 304, visible. This visible portion is designed to abut against a heat sink 206. The heat sink 206 is thus in thermal contact with each portion of the lower surface 502 visible through the overmolding 402. This thermal contact can be direct contact or contact through electrically insulated and thermally conductive connecting elements.

[0143] Furthermore, each retaining cavity 504 is filled by an overmolding member 402, and the overmolding member 402 has a lower surface in the retaining cavity 504 that is flush with the lower surface 502 of the main board 206.

[0144] Furthermore, it should be understood that the fixed end 314 of each electrical connector 3121, 3122, 3123, 3124 has a lower surface that is not completely covered by the overlay molding 402. Additionally, the overlay molding 402 fills each gap 310 and has a lower surface in each gap 310 that is flush with the lower surface 502 of the main board 206.

[0145] The overmolded component 402 has at least one downwardly projecting pad 506 designed to directly contact the heat sink 206 to define a predetermined gap between the lower surface 502 of the motherboard 206 and the heat sink 206, thereby defining the thickness of the thermally conductive element filling the gap. In the described example, each pad 506 protrudes from the lower surface of the overmolded component present in one of the gaps 310 between the motherboards 206.

[0146] Reference Figure 7 Each attachment tenon 322 has a fixed end 702 that is fixed to the edge surface (indicated by reference numeral 704) of the main board 306 that supports the attachment tenon 322. The attachment tenon also has an upper surface 706, a lower surface 708, two lateral surfaces 710, and a front surface 712, forming the free end of the attachment tenon 322. For clarity, these portions are shown with respect to only one of the attachment tenons 322, but it will be apparent to those skilled in the art that these portions are also present on the other attachment tenons 322. In the described example, the thickness of each attachment tenon 322 is equal to the thickness of the main board 306 that supports it. Furthermore, the upper surface 706 of the attachment tenon also extends in a continuation of the upper surface 308 of this main board 306.

[0147] Reference Figure 8 Typically, the overlay molding 402 at least partially covers one or more of the lower surface 708, upper surface 706, side surface 710, and front surface 712 of each attachment tenon 322.

[0148] In the example shown, the overlay molding 402 covers most of the side surface 710 of each attachment tenon 322, and makes its front surface 712, its lower surface 708 and most of its upper surface 706 visible.

[0149] To cover the side surfaces 710, the overmolding member 402 at least partially covers the edge surfaces 704 of the main plate 306, particularly between the two attachment tenons 322 of each pair of consecutive attachment tenons 322, especially those carried by the same main plate 306. This portion of the overmolding member 402 between the two attachment tenons 322 (indicated by reference numeral 806) extends from one of the two opposing side surfaces 710 of these attachment tenons 322 to the other, and covers a large portion of both side surfaces 710.

[0150] To make the upper surface 706 of the attachment tenon 322 visible, the overmolding member 402 has at least one cavity 802, which is in the form of a recess in the edge surface 804 of the overmolding member 402. The cavity 802 opens on the upper surface of the overmolding member 402. Therefore, the cavity 802 at least partially does not cover the upper surface 706 of at least one of the attachment tenons (one or more) 322.

[0151] Each attachment tenon 322 preferably protrudes at least 1 mm beyond the covering molded part 402 (that is, beyond the portion 806 in the illustrated example) in its protruding direction DP.

[0152] Reference Figure 9 In the described example, the lower face 708 of the attachment tenon 322 extends in the continuation of the lower face 502 of the main board 306. Furthermore, the overlay molding 402 does not extend further downward than the lower face 502 of the main board 306, and such that these lower faces 502 are completely uncovered, similar to the lower face 708 of the attachment tenon 322.

[0153] Reference Figure 10 The cavity 802 defines a free space that surrounds a straight cylinder with a circular bottom 1002 in the main plane PP. The diameter D of the circular bottom 1002 is 3 mm to 5 mm, preferably 4 mm, and its center C is located at a distance G from the connecting line L of the main plane PP at a distance between 0.5 mm and 1.5 mm, preferably 1 mm, connecting two portions of the edge surface 804 surrounding the cavity 802 of the covering molded part 402. The center C of the circular bottom 1002 is preferably vertically positioned relative to the middle of the width of the attachment tenon 322 (e.g., parallel to line L), and the upper surface 706 of the attachment tenon 322 is not covered by the cavity 802.

[0154] Reference Figure 11 and 12 In another embodiment, the overmolding 402 does not have a cavity 802 for at least one attachment tenon 322, such that the overmolding 402 covers most of the upper surface 706 of each of these attachment tenons 322.

[0155] Reference Figure 13 and 14 In another embodiment, the overmolded part 402 does not have a shape like... Figure 8 and 9 The cavity 802, as described above, also has a peripheral protrusion 1302 that interfaces with at least a portion of the outer edge of the overlying molded part 402 in the main plane and projects downward beyond the lower surface 502 of the main plate 306. This peripheral protrusion 1302 has, for example, the form of a low wall and at least partially covers the lower surface 708 of at least one attachment tenon 322. More specifically, in the described example, the peripheral protrusion 1302 covers the lower surface 708 over the entire width of the attachment tenon 322. Furthermore, in... Figure 13 and 14In the example shown, it can be understood that the peripheral protrusion 1302 covers the front of the fixing end 702 of the attachment tenon 322, thereby leaving the lower surface 708 of its fixing end 702 uncovered. This portion is formed by... Figure 14 The figure in the figure is indicated by reference numeral 1402.

[0156] Reference Figure 15 and 16 In another embodiment, the overmolded part 402 is similar to Figure 13 and 14 The difference lies in that it at least partially covers the front face 712 of at least one attachment tenon 322. In the example shown, the overlay molding 402 completely covers the front face of the attachment tenon 322 shown.

[0157] Reference Figure 17 and 18 In another embodiment, the overmolding member 402 completely covers at least one of the attachment tenons 322. In the example shown, the overmolding member 402 is similar to Figure 15 and 16 The difference in the molded part is that it completely covers the lower surface 708 of the attached tenon 322 shown.

[0158] Figure 19 and 20 Another embodiment of the power module 110 is shown. It is obvious that this other embodiment has the same... Figures 3 to 10 The same elements as those in the embodiments are indicated by the same reference numerals as those above. Figures 11 to 18 The variant embodiments are also applicable Figure 19 and 20 The power module.

[0159] Figure 21 and 22 A conductive plate 2100, preferably made of metal, is shown. This conductive plate extends in a main plane, and multiple planar portions are first cut into it. These planar portions have a frame portion 2102 and an electrical connection portion 304 for the power module 110 (in the illustrated example, ). Figures 3 to 10 (As described above), each electrical connection 304 has a main board and at least one electrical connector that may protrude from its main board. Figure 21 and 22In this configuration, electrical connectors 3121, 3122, and 3123 have been folded. Fastening lugs 2104 are also formed in the conductive plate 2100 for fastening each main board to at least one of other components (other connecting portions 304 or frame portions 2102). Also formed in the conductive plate 2100 are secondary fastening lugs for fastening each electrical connection that must be folded to at least one other electrical connecting portion or frame portion 2102. Figure 21 and 22 In this configuration, these secondary fastening lugs are not visible. Transistors 112 and 114 are fixed and electrically connected, and a cover molding 402 has been fabricated to completely cover at least a portion of the upper surface of transistors 112 and 114 and the motherboard, and also to at least partially cover at least some of the fastening lugs 2104. In the described example, the cover molding 402 extends to the plane of the lower surface of the motherboard of the connection portion 304.

[0160] Reference Figure 23 The method 2300 for manufacturing the power module 110 will now be described.

[0161] In step 2302, a conductive plate extending in the main plane is obtained.

[0162] In step 2304, the conductive plate obtained in the previous step is cut to define the frame portion 2102 and the connecting portion 304.

[0163] In step 2306, transistors 112 and 114 are fixed and electrically connected to the main board 306 of the connection part 304.

[0164] In step 2308, the overmolding 402 is made of an electrically insulating material (e.g., resin) to completely cover at least a portion of the upper surface 308 of the transistors 112, 114, the motherboard 306, and a portion of the upper surface of some of the fastening lugs 2104 (those designed to form attachment tenons 322). This step is preferably performed by casting or injection molding into a single mold cavity. More preferably, the mold has a shape that defines each cavity 802 in the overmolding 402, such that the upper surface of the fastening lugs 2104 is designed to form at least partially uncovered attachment tenons 322.

[0165] In step 2309, the secondary fastening lugs of electrical connectors 3121, 3122, and 3123 are cut.

[0166] In step 2310, as Figure 20 As shown, electrical connectors 3121, 3122, and 3123 are folded to position their main parts vertically in the described example. The result of this step is as follows: Figure 21 and 22 As shown.

[0167] In step 2312, the fastening lugs 2104 are cut to separate each electrical connection 304 from the other components (one or more). In the described example, this step first involves placing a reinforcing member against the upper surface of at least one fastening lug (preferably all fastening lugs), the upper surface of which is uncovered due to the presence of the cavity 802. Then, a cutting tool cuts the fastening lugs 2104 from bottom to top to create a shearing effect using the reinforcing member. The presence of the reinforcing member prevents deformation of the overmolded part during cutting, which could damage the overmolded part.

[0168] Therefore, the presence of one or more cavities 802 provides sufficient surface area to expose the upper surface of the fastening lug 2104, allowing the use of the aforementioned reinforcing member.

[0169] The fastening lug 2104 is cut so that for each fastening lug 2104 covered by the overlay molding 402, at least the portion covered by the overlay molding 402 remains as a fastening lug residue. Thus, this fastening lug residue forms one of the aforementioned attachment tenons 322.

[0170] In another embodiment, the overmolding 402 can be manufactured after the fastening lug 2104 has been cut. The overmolding 402 then covers at least the fastening lug residue, thus forming the attachment tenon 322.

[0171] In yet another embodiment, cutting the fastening lug 2104 includes cutting a first portion of the fastening lug 2104 (those designed to form the attachment tenon 322), then manufacturing the overlay mold 422, and then cutting a second portion of the fastening lug 2104.

[0172] In yet another embodiment, the manufacture of the overmolding part 402 includes manufacturing a first portion of the overmolding part (such as...). Figure 20 and 21 (As shown), then the fastening lugs 2104 (at least those designed to form the attachment lugs 322) are cut, and then the second part of the overmolding 402 is manufactured on the first part of the overmolding. In particular, the second part of the overmolding can cover the front of the attachment lugs 322, which is not possible in the manufacturing process of the first part of the overmolding because the fastening lugs 2104 are not cut.

[0173] Obviously, the power module described above allows the molded part to be held in place, thus preventing it from detaching.

[0174] It should also be noted that the present invention is not limited to the embodiments described above. In fact, it will be apparent to those skilled in the art that various modifications can be made to the above embodiments based on the teachings disclosed herein.

[0175] In the detailed description of the invention given above, the terminology used should not be construed as limiting the invention to the embodiments disclosed herein, but should be understood to include all equivalents that are expected to fall within the scope of a person skilled in the art applying his or her general knowledge to the implementation of the teachings disclosed herein.

Claims

1. A power module (110) comprising: - electrical connection portions (304), each electrical connection portion having a main plate (306) extending in a same main plane (PP) to be substantially coplanar, at least one of the electrical connection portions (304) comprising at least one electrical connector (3121, 3122, 3123, 3124) protruding from its main plate (306); - at least one transistor (112, 114) electrically connected between two upper faces (308) of a respective two of the main plates (306); and - an electrically insulating overmold (402) covering each transistor (112, 114) and at least a portion of the upper face (308) of the main plate (306); characterized in that - at least one of the electrical connection portions (304) further having at least one attachment tab (322) for attachment to the overmold (402), the attachment tab being separate from the electrical connector (3121, 3122, 3123, 3124) of the electrical connection portion (304) when the electrical connection portion (304) comprises the electrical connector (3121, 3122, 3123, 3124), each attachment tab (322) protruding from an edge surface (704) of the main plate (306) of the electrical connection portion (304) in only one protrusion direction (DP) in the main plane (PP), and the overmold (402) at least partially covering the attachment tab (322); wherein each attachment tab (322) has: - a fixed end (702) fixed to the edge surface (704) of the main plate (306), - an upper face (706), - a lower face (708), - two lateral faces (710), and - a front face (712), and wherein the overmold (402) at least partially covers one or more of the following: the lower face (708), the upper face (706), the lateral faces (710) and the front face (712) of each attachment tab (322) and wherein the overmold (402) has at least one cavity (802) such that the upper face (706) of at least one of the one or more attachment tabs (322) is at least partially uncovered.

2. The power module (110) of claim 1, wherein, At least one of the main plates (306) has at least one cavity (504) filled by the overmold (402) on a lower face (502), and wherein the overmold (402) has a lower face in the cavity (504) that is flush with the lower face (502) of the main plate (306).

3. The power module (110) of claim 1 or 2, wherein The electrical connection portions (304) are obtained by cutting from a metal plate (2100).

4. The power module (110) of claim 1 or 2, wherein The cavity (802) defines a free space which encloses a right circular cylinder having a circular base (1002) in the main plane (PP) with a diameter (D) of 3 mm to 5 mm and a center (C) located at a distance (G) of 0.5 mm to 1.5 mm from a line (L) of the main plane (PP) connecting two portions of an edge surface (804) of the overmold (402) surrounding the cavity (802).

5. The power module (110) of claim 4, wherein, The center (C) of the circular base (1002) is positioned vertically with respect to the middle of the width of the attachment tenon (322).

6. The power module (110) of claim 1 or 2, wherein The overmold (402) has a peripheral protrusion (1302) at least partially bordering an outer edge of the overmold (402) in the main plane (PP) and protruding further downward than the lower face (502) of one or more of the main plates (306), which peripheral protrusion (1302) at least partially covers the lower face (706) of at least one of the one or more attachment tenons (322).

7. The power module (110) of claim 6, wherein, The front face (712) of at least one of the attachment tenons (322) having a lower face (706) covered by the peripheral protrusion (1302) is completely covered by the overmold (402).

8. The power module (110) of claim 1, wherein, The electrical connections are made of metal.

9. The power module (110) of claim 1, wherein, The electrically insulating overmold is made of resin.

10. The power module (110) of claim 4, wherein, The diameter (D) of the circular base (1002) is 4 mm.

11. The power module (110) of claim 4, wherein, The center (C) is located at a distance (G) of 1 mm from a line (L) of the main plane (PP).

12. The power module (110) of claim 7, wherein, The front face (712) is completely covered by the peripheral protrusion (1302) of the overmold (402).

13. An electronic system comprising a heat sink (206) and a power module (110) as claimed in one of the claims 1 to 12, and wherein, The heat sink (206) is in thermal contact with at least one lower face (502) visible through the overmold (402).

14. A voltage converter (104) comprising a power module (110) according to any one of claims 1 to 12 or an electronic system according to claim 13.

15. A method (2300) for manufacturing a power module (110), comprising the steps of: obtaining (2302) an electrically conductive plate (2100) extending in a main plane (PP); cutting (2304) out of the electrically conductive plate (2100), on the one hand, a frame portion (2102) and a plurality of planar portions having at least two electrical connections (304), each electrical connection having a main plate (306) extending in the main plane (PP) to be substantially coplanar, at least one electrical connection (304) comprising at least one electrical connector (3121, 3122, 3123, 3124) protruding from its main plate (306); and, on the other hand, a fastening lug (2104) for fastening each main plate (306) to at least one other component; electrically connecting (2306) at least one transistor between two upper faces of two respective main plates; overmolding at least a portion of the upper face of the transistor and of the main plate with an electrically insulating material (2308); and cutting (2310) the fastening lugs (2104) so as to separate each electrical connection (304) from other components (one or more); characterized in that the fastening lugs (2104) are cut so as to leave fastening lug residues that protrude from one of the main plates and form attachment tenons (322) for attachment to the overmolding (402) that protrudes from the main plate (306) in the main plane (PP), the attachment tenons being separate from the electrical connectors (3121, 3122, 3123, 3124) of the electrical connection (304) when the electrical connection (304) comprises the electrical connectors (3121, 3122, 3123, 3124), each attachment tenon (322) protruding from an edge surface (704) of the main plate (306) of this electrical connection (304) only in one direction of protrusion (DP) in the main plane (PP), and the overmolding (402) is made so as to at least partially cover the attachment tenons (322).

16. The method (2300) of claim 15, wherein, The electrically conductive plate is made of metal.

17. The method (2300) of claim 15, wherein, The electrically insulating material is a resin.

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