Semiconductor power module and method and tool for manufacturing such a module

Abstract

A semiconductor power module (10) is disclosed, comprising one or more semiconductors (4) placed on a substrate (7). The power module (10) comprises a contact formed by a contact pin (6), the contact pin being provided with a plastic sleeve (5) having a central portion (13). The contact pin (6) comprises a longitudinal axis (Y). The plastic sleeve (5) encloses a portion of the contact pin (6). The distal portion of the sleeve (5) comprises a plastic deformation zone (8). The sleeve (5) encloses a proximal portion of the contact pin (6), wherein the sleeve (5) is continuous from its distal portion to its proximal portion, and the proximal portion is in direct contact with the substrate (7) or a structure (9) in direct contact with the substrate (7).

Description

Technical Field

[0001] The present invention relates to a plastic encapsulation tool for plastic encapsulating a semiconductor power module, and also relates to a semiconductor power module and a method for manufacturing the semiconductor power module. Background Art

[0002] In the field of power electronics, modules with frames and modules with plastic packaging are well known. Such modules include semiconductor components, such as semiconductor switches in the form of, for example, IGBTs or MOSFETs. Such components can use silicon-based semiconductors, or, as is becoming increasingly common, wide-bandgap semiconductors, such as silicon carbide (SiC) or gallium nitride (GaN)-based semiconductors. In power modules, it is known to use load and control pins, which extend out of the plastic packaging housing through openings provided in the plastic packaging housing.

[0003] For power modules that use high switching frequencies in operation, especially when using wide bandgap semiconductor technology, it is crucial that the contact pins extend along the shortest possible path while connecting the component and the control electronics or the load. However, plastic encapsulated power modules with top contact pins are rare because the required production steps are difficult to implement.

[0004] Contact pins having the same height as the molding compound are known, wherein the contact pins are fastened to the substrate before molding.

[0005] It is also known to have contact pins that are higher than the molding compound and therefore extend beyond the molding compound in the finished module. These contact pins are fastened to the substrate before the molding process. In order to implement the molding process, it is necessary to apply sealing elements that are firmly or semi-firmly connected to the contact pins. These sealing elements need to be fixed to the contact pins before the contact pins are attached to the substrate.

[0006] One of the disadvantages of the prior art solution is that the sealing element is connected to the contact pins before the contact pins are attached to the substrate. Therefore, ultrasonic welding of the contact pins is difficult and requires complex tools. Therefore, methods for attaching the contact pins to the substrate, such as welding or adhesive bonding, are rarely used. If the installation of the sealing element is performed after the contact pins are attached (while using the prior art solution), the sealing element will not apply any pressure towards the sealing point of the opening in the upper mold. This has the undesirable consequence that the molding compound may enter the opening in the upper mold tool. This may lead to problems such as overflow of the molding compound during the molding process and contamination of the mold or the contact pins.

[0007] Therefore, a molding tool, a method, a semiconductor power module and a contact pin unit are needed to reduce or even eliminate the above-mentioned disadvantages of the prior art.

[0008] The object of the present invention is to provide a molding tool and a method in which a sufficiently tight seal of an opening in an upper mold tool can be established. It is also an object to provide a semiconductor power module which can be manufactured without the above-mentioned disadvantages.

[0009] A further object of the present invention is to provide a contact pin unit suitable for use in the above molding tool and method so as to manufacture a power module having the above advantages. Summary of the invention

[0010] The objects of the invention can be achieved by a molding tool as defined in claim 1, a method as defined in claim 5, a semiconductor power module as defined in claim 10 and a contact pin unit as defined in claim 15. Preferred embodiments are defined in the dependent claims, explained in the following description and illustrated in the drawings.

[0011] The molding tool according to the present invention is a molding tool for molding a semiconductor power module, wherein the power module comprises a substrate and an electrical contact pin electrically connected to the substrate, wherein the molding tool comprises an upper mold tool and a lower mold tool, wherein the upper mold tool and the lower mold tool are configured to engage and thereby form a mold cavity to be filled with an encapsulation molding compound so as to encapsulate electrical components of the semiconductor power module, wherein the upper mold tool is provided with an opening, wherein the opening is configured to receive a distal portion of the electrical contact pin, wherein the opening comprises:

[0012] - a centrally arranged cylindrical portion having a longitudinal axis and a width, and

[0013] - an inclined portion which is angled in the range of 20 to 70 degrees relative to the longitudinal axis, wherein the width of the inclined portion exceeds 1.5 times the width of the cylindrical portion.

[0014] Thus, a molding tool can be provided by which a sufficiently tight seal of the opening in the upper mold tool can be provided.Thus, during molding, the contact pins can be kept completely free of molding compound so that the pins provide good electrical conductivity when connected to an electrical component.

[0015] The substrate may be a Direct Copper Bonding (DCB) substrate. It may be advantageous to use a DCB substrate due to its good thermal conductivity.

[0016] The electrical contact pins are electrically connected to the substrate. The pins may be solder pins. In one embodiment, the pins are press-fit pins adapted to be inserted into holes in a printed circuit board (PCB). In one embodiment, the pins include holes or threaded holes formed to connect using a threaded connection.

[0017] The molding tool includes an upper mold tool and a lower mold tool configured to engage and thereby form a mold cavity to be filled with an encapsulation molding compound.

[0018] The upper mold tool is provided with an opening configured to receive the distal portion of the electrical contact pin, thereby preventing the molding compound from contacting the distal portion of the electrical contact pin during the molding process.

[0019] Openings include:

[0020] - a centrally arranged cylindrical portion having a longitudinal axis and a width, and

[0021] - an inclined portion which is angled in the range of 20 to 70 degrees relative to the longitudinal axis, wherein the width of the inclined portion exceeds 1.5 times the width of the cylindrical portion.

[0022] In one embodiment, the inclined portion is arranged adjacent to the cylindrical portion.

[0023] In one embodiment, the intermediate portion may be disposed between the inclined portion and the cylindrical portion.

[0024] In a preferred embodiment, the inclined portion extends in the extension of the cylindrical portion such that the inclined portion protrudes from the cylindrical portion.

[0025] In one embodiment, the angle relative to the longitudinal axis of the cylindrical portion is in the range of 30 to 60 degrees.

[0026] In one embodiment, the angle relative to the longitudinal axis of the cylindrical portion is in the range of 35 to 55 degrees.

[0027] In one embodiment, the angle relative to the longitudinal axis of the cylindrical portion is in the range of 40 to 50 degrees.

[0028] In one embodiment, the surface of the inclined portion is conical.

[0029] In one embodiment, a cross-section of the surface of the inclined portion comprises a planar segment.

[0030] In one embodiment, the surface of the inclined portion is convex. This may be advantageous when a concave surface of the molded area surrounding the pin is desirable.

[0031] In one embodiment, a cross-section of the surface of the inclined portion includes a concave portion.

[0032] In one embodiment, the surface of the inclined portion is concave. This may be advantageous when a convex surface of the molded area surrounding the pin is desirable.

[0033] In one embodiment, the opening comprises a substantially cylindrical proximal portion. This is an advantage because the substantially cylindrical proximal portion facilitates insertion of the distal portion of the pin.

[0034] In one embodiment, a cross-section of the surface of the inclined portion comprises a convex portion.

[0035] In one embodiment, the width of the cylindrical portion is greater than the width of the distal portion of the contact pin and less than the width of the proximal portion of the contact pin.

[0036] In one embodiment, the maximum width of the inclined portion is equal to or twice the width of the cylindrical portion of the contact pin.

[0037] The method according to the invention is a method for manufacturing a semiconductor power module having a substrate and electrical contact pins electrically connected to the substrate, wherein the contact pins have a longitudinal axis, wherein the contact pins are provided with a plastic sleeve having a central portion, wherein the method comprises the following steps:

[0038] - arranging the sleeve in a position where the sleeve encloses a portion of the contact pin, wherein the sleeve is continuous from its distal portion to its proximal portion, and the proximal portion is in direct contact with the substrate or a structure in direct contact with the substrate;

[0039] - Providing a plastically deformable zone in a distal portion of the sleeve, wherein the sleeve transmits a force for plastically deforming the plastically deformable zone along a longitudinal axis of the contact pin to the substrate or a structure in direct contact with the substrate.

[0040] The method thus makes it possible to provide a sufficiently tight sealing of the opening in the upper mould tool.Thus, during moulding, the contact pins can remain completely free of moulding compound, so that the pins provide good electrical conductivity when connected to an electrical component.

[0041] The use of a plastic sleeve makes it possible to provide a plastically deformable zone in the distal portion of the sleeve.The geometry of the sleeve should be selected according to the geometry of the contact pins and the opening.

[0042] The method comprises the step of arranging the sleeve in a position where the sleeve encloses a portion of the contact pin, wherein the sleeve is continuous from its distal portion to its proximal portion and the proximal portion is in direct contact with the substrate or a structure in direct contact with the substrate. This step makes it possible to provide a sufficiently tight seal of the opening in the upper mold tool. This can be achieved by keeping the proximal portion of the sleeve in direct contact with the substrate or a structure in direct contact with the substrate. As an example, the structure in direct contact with the substrate can be a proximal structure of the contact pin.

[0043] When the upper and lower mold tools are pressed together, a plastic deformation zone is generated in the distal portion of the sleeve. This can be achieved because the sleeve transfers the force used to plastically deform the plastic deformation zone along the longitudinal axis of the contact pin to the substrate or a structure in direct contact with the substrate.

[0044] In one embodiment, the plastically deformed zone is produced by using a molding tool according to the present invention.

[0045] In one embodiment, the sleeve has a central portion, wherein the plastically deformable zone protrudes from the central portion of the sleeve. This will make it easier for the plastically deformable zone to seal against the opening.

[0046] In one embodiment, the contact pin comprises a foot portion arranged at a proximal end of the contact pin, wherein the foot portion protrudes from a central portion of the contact pin, wherein the foot portion extends perpendicular to a longitudinal axis of the contact pin. When the upper die tool and the lower die tool are pressed together, a plastic deformation zone is generated in a distal portion of the sleeve because the sleeve transfers a force (for plastically deforming the plastic deformation zone) along the longitudinal axis of the contact pin to the foot portion in direct contact with the substrate.

[0047] In one embodiment, the sleeve includes a protruding portion disposed at a proximal end of the sleeve, wherein the protruding portion protrudes from a central portion of the sleeve, wherein the protruding portion extends perpendicular to a longitudinal axis of the contact pin. When the upper die tool and the lower die tool are pressed together, a plastic deformation zone is generated in a distal portion of the sleeve because the sleeve transfers a force (for plastically deforming the plastic deformation zone) along the longitudinal axis of the contact pin to the protruding portion in direct contact with the substrate.

[0048] The semiconductor power module according to the present invention is a semiconductor power module comprising:

[0049] - one or more semiconductors, the one or more semiconductors being placed on a substrate;

[0050] - a contact formed by a contact pin provided with a plastic sleeve having a central portion, wherein the contact pin comprises a longitudinal axis, wherein the plastic sleeve encloses a portion of the contact pin and a distal portion of the sleeve comprises a plastic deformation zone, wherein the sleeve encloses a portion of the contact pin, wherein the sleeve is continuous from its distal portion to its proximal portion and the proximal portion is in direct contact with a substrate or a structure in direct contact with the substrate, wherein the sleeve is suitable for transmitting a force along the longitudinal axis to the substrate or a structure in direct contact with the substrate, the force being sufficient to plastically deform the plastic deformation zone.

[0051] Therefore, the plastic deformation zone is arranged and configured to act as a sealing element during the molding process and prevent the molding compound from flowing into the opening on the upper mold tool. Therefore, during the molding process, the contact pins can be kept completely free of molding compound so that the pins provide good electrical conductivity when connected to the electrical component.

[0052] The semiconductor power module may comprise several semiconductors.In one embodiment, the substrate is a DCB substrate.

[0053] A semiconductor power module may include several electrical contact pins, each electrically connected to a substrate.

[0054] In one embodiment, the contact pin comprises a foot having a width greater than a width of a distal portion of the contact pin. Thus, a plastic deformation zone may be provided in the distal portion of the sleeve by transferring a force for plastically deforming the plastic deformation zone along the longitudinal axis of the contact pin to the foot of the contact pin attached to the substrate.

[0055] In one embodiment, the sleeve comprises a protruding portion disposed at the proximal end of the sleeve, wherein the protruding portion protrudes from a central portion of the sleeve, wherein the protruding portion extends perpendicularly to a longitudinal axis of the contact pin. Thus, a force required to plastically deform the plastically deformable zone in the distal portion of the sleeve can be transmitted to the substrate via the sleeve through the protruding portion disposed in the proximal end of the sleeve.

[0056] In one embodiment, the plastically deformable zone protrudes from a central portion of the sleeve. Thus, the plastically deformable zone can seal against the inclined portion of the opening in an effective manner.

[0057] It may be advantageous to manufacture a power module by using the method according to the invention.

[0058] The contact pin unit according to the present invention comprises:

[0059] - an electrical contact pin having a longitudinal axis,

[0060] Wherein, the contact pin is provided with a plastic sleeve having a central portion,

[0061] The sleeve encapsulates a portion of the contact pin.

[0062] wherein the sleeve is continuous from a distal portion thereof to a proximal portion thereof, and the proximal portion is adapted to be in direct contact with the substrate or a structure in direct contact with the substrate; and

[0063] The distal portion of the sleeve has a plastic deformation zone.

[0064] The sleeve can transmit the force for plastically deforming the plastically deformable region to the substrate or a structure in direct contact with the substrate along the longitudinal axis of the contact pin. The contact pin unit is suitable for forming an electrical connection with the substrate.

[0065] In one embodiment, the plastically deformable zone protrudes from a central portion of the sleeve.

[0066] In another embodiment, the contact pin comprises a foot arranged at a proximal end of the contact pin, wherein the foot protrudes from a central portion of the contact pin, wherein the foot extends perpendicularly to a longitudinal axis of the contact pin.

[0067] In further embodiments, the sleeve comprises a protruding portion disposed at a proximal end of the sleeve, wherein the protruding portion protrudes from a central portion of the sleeve, wherein the protruding portion extends perpendicular to a longitudinal axis of the contact pin.

[0068] In further embodiments, the sleeve comprises a material that shrinks significantly at the temperatures used during the molding process. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] The present invention will be more fully understood from the detailed description given below. The accompanying drawings are given by way of illustration only and therefore, they are not limiting of the present invention. In the drawings:

[0070] Figure 1 A schematic cross-sectional view showing a side view of a semiconductor power module arranged in a molding tool according to the present invention;

[0071] Figure 2 Shows Figure 1 Schematic cross-sectional view of a semiconductor power module in a configuration in which a plastic deformation zone has been created at the distal end of the plastic sleeve, wherein the power module is arranged in Figure 1 In the plastic packaging tool shown in;

[0072] Figure 3 Shown by using Figure 1 and Figure 2 A schematic cross-sectional view of a semiconductor power module manufactured by a molding tool shown in FIG.

[0073] Figure 4shows a schematic cross-sectional view of another semiconductor power module according to the present invention;

[0074] Figure 5 shows a schematic cross-sectional view of a further semiconductor power module according to the invention;

[0075] Figure 6 A schematic cross-sectional view showing a side view of a semiconductor power module arranged in a molding tool according to the present invention;

[0076] Figure 7 Shows Figure 6 Schematic cross-sectional view of a semiconductor power module in a configuration in which a plastic deformation zone has been generated at the distal end of a plastic sleeve placed on a substrate of the power module, wherein the power module is arranged Figure 6 In the plastic packaging tool shown in;

[0077] Figure 8 A schematic cross-sectional view of a semiconductor power module arranged in a molding tool according to the present invention is shown;

[0078] Fig. 9 Shown by using Figure 8 A schematic cross-sectional view of a semiconductor power module manufactured by a molding tool shown in FIG.

[0079] Fig.10 A flow chart showing the method steps for manufacturing a semiconductor power module according to the present invention is shown;

[0080] Fig.11 a schematic cross-sectional view showing a side view of a semiconductor power module arranged in a molding tool according to the invention; and

[0081] Fig.12 Shows Fig.11 Schematic cross-sectional view of a semiconductor power module in a configuration in which a plastic deformation zone has been produced at the distal end of a plastic sleeve placed on a substrate of the power module, wherein the power module has been removed from a molding tool. DETAILED DESCRIPTION

[0082] To illustrate the preferred embodiments of the present invention, reference will now be made in detail to the accompanying drawings, in which Figure 1 2 shows a schematic cross-sectional view of a side view of a semiconductor power module 10 according to the invention arranged in a molding tool.

[0083] The semiconductor power module 10 includes a substrate 7. The substrate may be a direct copper bonding (DCB) substrate consisting of a ceramic sheet sandwiched between two sheets of copper. Electrical contact pins 6 are attached to the upper surface of the substrate 7 to electrically connect the contact pins 6 to the surface. The contact pins 6 extend from the surface of the substrate 2 and are positioned to be inserted into the opening 3 of the upper mold tool 1. The longitudinal axis Y of the contact pins 6 extends parallel to the longitudinal axis X of the opening 3. The longitudinal axis Y of the contact pins 6 extends perpendicular to the longitudinal axis Z of the substrate 7. The semiconductor 4 is placed on the substrate 7.

[0084] The substrate 7 is placed in the lower mold tool 2. The upper mold tool 1 and the lower mold tool 2 are configured to engage and thereby form a mold cavity to be filled with molding compound to encapsulate the electrical component (semiconductor) 4. The opening 3 of the upper mold tool 1 is configured to receive the distal portion of the electrical contact pin 6.

[0085] The contact pin 6 comprises a foot 9 arranged in the proximal end of the contact pin 6. The foot 9 is electrically connected to the upper surface of the substrate 7. The width L6 of the foot 9 is indicated. It can be seen that the width L1 of the distal part of the contact pin 6 is smaller than the width L6 of the foot 9, because the foot 9 extends perpendicularly to the longitudinal axis Y of the contact pin 6.

[0086] The opening 3 comprises a proximal, centrally arranged cylindrical portion, the width L2 of which is greater than the width L1 of the distal portion of the contact pin 6. Thus, the distal portion of the contact pin 6 can be inserted into the cylindrical portion in the opening 3 and received thereby.

[0087] The plastic sleeve 5 encloses a portion of the contact pin 6. The sleeve 5 rests on the foot 9 of the contact pin 6.

[0088] The opening 3 comprises an inclined portion 11. An angle α between the longitudinal axis X of the opening and the inclined portion 11 is approximately 45 degrees. The angle α may be different from 45 degrees. In one embodiment, the angle α is in the range of 30 to 60 degrees.

[0089] The width L7 of the inclined portion 11 is more than twice the width L2 of the cylindrical portion. The inclined portion 11 is arranged adjacent to the cylindrical portion and is designed to provide a plastic deformation zone in the distal portion of the sleeve 5. The sleeve 5 is arranged in a position when the sleeve 5 encloses the proximal portion of the portion extending from the foot 9 that contacts the pin 6. The sleeve 5 is continuous from its distal portion to its proximal portion, and the proximal portion of the sleeve 5 is in direct contact with the foot 9, which is in direct contact with the upper surface of the base plate 7.

[0090] The inclined portion 11 is configured to provide a plastic deformation zone in the distal portion of the sleeve 5 when the upper die tool 1 and the lower die tool 2 are pressed together. When the upper die tool 1 and the lower die tool 2 are pressed together, the sleeve 5 transfers the force for plastically deforming the plastic deformation zone to the foot 9 along the longitudinal axis Y of the contact pin 6. Because the foot 9 is in direct contact with the upper surface of the substrate 7, the force will be transferred to the substrate 7 through the foot 9.

[0091] Figure 1 3 shows the length L5 of the cylindrical portion and the length L4 of the inclined structure 11 of the opening 3 (along the longitudinal axis X). Likewise, the width L3 of the inclined structure of the inclined portion 11 is indicated. It can be seen that Figure 1 The cross section of the inclined portion 11 shown in FIG. 1 includes a plane section. In fact, Figure 1 The surface of the cross section of the inclined portion 11 shown in FIG. 1 is flat. However, Figure 1 The surface of the inclined portion 11 shown in FIG. 1 may be conical.

[0092] It is important to emphasize that the power module 10 may include Figure 1 A single semiconductor 4 is shown in more electrical components 4 .

[0093] Figure 2 Shown Figure 1 Schematic cross-sectional view of a semiconductor power module 10 in such a configuration is shown in FIG. 1 , in which a plastic deformation zone 8 has been produced in the distal end of the plastic sleeve 5 . The power module 10 is arranged in Figure 1 . The upper mold tool 1 and the lower mold tool 2 have been pressed together. Therefore, the sleeve 5 has transmitted the force for plastically deforming the plastically deformable zone 8 along the longitudinal axis Y of the contact pin 6. The plastic deformation zone 8 tightly seals the mold cavity 14 of the lower mold tool 2 against the opening 3 of the upper mold tool 1. Therefore, the molding compound can be injected into the mold cavity 14 in a way that no molding compound enters the opening 3.

[0094] Figure 3 Demonstrated by using Figure 1 and Figure 2 Schematic cross-sectional view of a semiconductor power module 10 after molding by a molding tool shown in FIG. The molding compound has been injected into the mold cavity of the lower mold tool (see FIG. Figure 2 ).

[0095] Figure 4 A schematic cross-sectional view of another semiconductor power module 10 according to the present invention is shown. In addition to the bushing 5, the power module 10 corresponds to Figure 3 In the power module shown in FIG. 1 , the bushing is divided into an upper sheet-like member 5 ′ and a lower sheet-like member 5 ″ which are arranged one above the other.

[0096] Figure 5 A schematic cross-sectional view of a further semiconductor power module 10 according to the invention is shown. The power module 10 corresponds substantially to Figure 3 However, the contact pin 6 does not include a foot, and the sleeve 5 is provided with a protruding portion 12. When force is transmitted through the sleeve 5 to provide the plastic deformation zone 8, the protruding portion 12 distributes the force to a larger area of ​​the upper surface of the substrate.

[0097] Figure 6 A schematic cross-sectional view of a side view of a semiconductor power module 10 arranged in a molding tool according to the present invention is shown. The semiconductor power module 10 and the molding tool essentially correspond to Figure 1 However, the contact pin 6 does not include a foot, and the sleeve 5 has a protruding portion 12, similar to Figure 5 In fact, Figure 5 The semiconductor power module 10 shown in FIG. Figure 6 and Figure 7 The plastic packaging tools 1 and 2 shown in are made.

[0098] Figure 7 Shown Figure 6 Schematic cross-sectional view of a semiconductor power module 10 in a configuration in which a plastic deformation zone 8 has been created in the distal end of a sleeve 5. The sleeve 5 is placed on the upper surface of a substrate 7 of the power module 10. The power module 10 is arranged in a manner corresponding to Figure 6 In the molding tool of the molding tool shown in FIG.

[0099] Figure 8 A schematic cross-sectional view of a semiconductor power module 10 according to the invention arranged in a molding tool is shown. Fig. 9 Demonstrated by using Figure 8 A schematic cross-sectional view of a semiconductor power module 10 manufactured by a molding tool shown in FIG. The upper mold tool 1 and the lower mold tool correspond to Figure 1 , Figure 2 , Figure 6 and Figure 7 The semiconductor power module 10 basically corresponds to the upper mold tool and the lower mold tool shown in FIG. Figure 1 3 and explained with reference to the figure. However, the contact pin 6 does not include a foot. The contact pin 6 is cylindrical, and its distal portion has been received by the cylindrical portion of the opening 3. The sleeve 5 is in direct contact with the upper surface of the substrate 7. The compressive force provided while the upper die tool 1 and the lower die tool 2 are engaged causes the inclined portion 11 of the opening 3 to contact the distal portion of the sleeve 5 and press toward it. As a result, a plastic deformation zone 8 is generated.

[0100] like Figure 8 and Fig. 9 As shown, the geometry of the inclined portion 11 defines the geometry of that portion of the plastic deformation zone 8 that contacts the inclined portion 11 at the end of the formation of the plastic deformation zone 8 .

[0101] Fig.10 A flow chart is shown which illustrates the method steps for producing a semiconductor power module according to the invention.

[0102] In a first step, the plastic sleeve 5 is arranged outside a portion of the contact pin 6 of the semiconductor power module 10. The position of the sleeve 5 depends on the geometry of the contact pin 6 and the sleeve 5. If the contact pin 6 includes a foot (e.g. Figure 1 and Figure 2 As shown), the sleeve 5 will be placed on the foot. However, if the contact pin 6 does not include a foot, but is cylindrical (as shown in FIG. Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 2 As shown in FIG. 1 , the sleeve 5 will be placed on the upper surface of the substrate or on a structure (such as a thin plate) that is in direct contact with the upper surface of the substrate.

[0103] In a next step, the power module 10 is inserted into a molding tool comprising an upper mold tool 1 having an opening 3 provided with an inclined distal portion 11. Figure 1 , Figure 2 , Figure 6 , Figure 7 , Figure 8 and Fig.11 Shown in.

[0104] In the next step, the upper mold tool 1 and the lower mold tool 2 are pushed together so that the distal portion of the plastic sleeve 5 contacts the inclined distal portion 11 , causing the distal portion of the plastic sleeve 5 to be plastically deformed.

[0105] In the next step, the molding compound is injected into the mold cavity of the molding tool, thereby the power module 10 is molded simultaneously inside the molding tool.

[0106] Finally, the mould is opened (by moving the upper mould tool 1 and the lower mould tool 2 away from each other) and the moulded module 10 is removed from the moulding tool.

[0107] In an alternative method, a contact pin unit is first formed. Such a contact pin unit includes:

[0108] - an electrical contact pin having a longitudinal axis,

[0109] Wherein, the contact pin is provided with a plastic sleeve having a central portion,

[0110] The sleeve encapsulates a portion of the contact pin.

[0111] wherein the sleeve is continuous from a distal portion thereof to a proximal portion thereof, and the proximal portion is adapted to be in direct contact with the substrate or a structure in direct contact with the substrate; and

[0112] The distal portion of the sleeve has a plastic deformation zone.

[0113] Therein, the sleeve can transmit the force for plastically deforming the plastically deformable region along the longitudinal axis of the contact pin to the substrate or a structure in direct contact with the substrate.

[0114] Once assembled, such a contact pin unit can be placed in a suitable position on a substrate of, for example, a semiconductor power module. The power module can then be inserted into a molding tool as described in the above method. The use of such a contact pin unit enables the production of a molded power module without the step of arranging a plastic sleeve 5 on the already installed contact pins.

[0115] In a further alternative approach, the sleeve 5 may comprise a material that shrinks significantly at the temperature used during the molding process. Such material is referred to as "shrink tubing", "heat shrink" or "heat shrink tubing" and may be made of thermoplastic materials such as silicone elastomers, fluoropolymers, PVC, neoprene or polyolefins. Thus, such a sleeve 5 may fit relatively loosely over the contact pins and form a much tighter fit when the power module 10 is inserted into the molding tool and subjected to the molding process. As a result, a sufficient seal is achieved after molding so that moisture cannot penetrate into the module.

[0116] Fig.11 A schematic cross-sectional view of a side view of a semiconductor power module 10 according to the invention arranged in a molding tool 1 , 2 is shown. Fig.12 Shown Fig.11 Schematic cross-sectional view of a semiconductor power module 10 in a configuration in which a plastic deformation zone 8 has been produced at the distal end of a plastic sleeve 5 placed on a substrate 7 of the power module 10, wherein the power module 10 has been removed from the molding tools 1, 2.

[0117] Plastic sealing tools 1 and 2 correspond to Figure 1 , Figure 2 , Figure 6 , Figure 7 and Figure 81 and explained with reference to these figures. The sleeve 5 has a width L7 which corresponds substantially to the width of the inclined portion 11 of the opening 3. Therefore, the plastic deformation zone 8 does not protrude from the cylindrical portion of the sleeve 5 in a direction perpendicular to the longitudinal axis Y of the contact pin 6. Nevertheless, the inclined portion 11 is able to seal tightly against the opening 3 so that no injected molding compound enters the opening during the molding process.

[0118] List of Reference Numerals

[0119] 1 Die tool

[0120] 2 Die tool

[0121] 3 Opening on the upper tool

[0122] 4 Semiconductors

[0123] 5 Casing

[0124] 5' Upper casing component

[0125] 5” casing assembly

[0126] 6 Contact pins

[0127] 7 substrate

[0128] 8 Plastic deformation zone / plastic deformation zone

[0129] 9. Feet

[0130] 10 Semiconductor power module

[0131] 11. Inclined section

[0132] 12 Protruding part of the casing

[0133] 13 Center section of the casing

[0134] 14 Cavity

[0135] X, Y longitudinal axis

[0136] α Angle

[0137] L1, L2, L3, L6 Width

[0138] L4, L5 length

Claims

1. A method for manufacturing a semiconductor power module (10), the semiconductor power module having a substrate (7) and electrical contact pins (6) electrically connected to the substrate (7), wherein: The contact pin (6) has a longitudinal axis (Y), wherein the contact pin (6) is provided with a plastic sleeve (5) having a central portion (13), characterized in that the method comprises the following steps: - arranging the sleeve (5) in a position where the sleeve (5) encloses a portion of the contact pin (6), wherein the sleeve (5) is continuous from its distal portion to its proximal portion, and a) the proximal portion is in direct contact with the substrate (7), or b) a structure in direct contact with the substrate (7), wherein the structure is a foot (9) arranged at the proximal end of the contact pin; - a plastically deformable zone (8) is provided in the distal portion of the sleeve (5), wherein the sleeve (5) transmits the force for plastically deforming the plastically deformable zone (8) along the longitudinal axis (Y) of the contact pin (6) to the substrate (7) or the structure in direct contact with the substrate (7).

2. The method according to claim 1, wherein: The plastic deformation zone (8) is manufactured using a molding tool for molding a semiconductor power module (10), wherein the power module (10) comprises a substrate (7) and an electrical contact pin (6) electrically connected to the substrate (7), wherein the molding tool comprises an upper mold tool (1) and a lower mold tool (2), wherein the upper mold tool and the lower mold tool are configured to be joined together and thereby form a mold cavity to be filled with molding compound so as to encapsulate the electrical component (4) of the semiconductor power module (10), wherein the upper mold tool (1) is provided with an opening (3), wherein the opening is configured to receive a distal portion of the electrical contact pin (6), wherein the opening (3) comprises the following items: - a centrally arranged cylindrical portion having a longitudinal axis (X) and a width (L2), and - an inclined portion (11) which forms an angle (α) in the range of 20 to 70 degrees with respect to the longitudinal axis (X), wherein the width (L7) of the inclined portion (11) exceeds 1.5 times the width (L2) of the cylindrical portion.

3. The method according to claim 1, wherein: The sleeve (5) has a central portion (13), Therein, the plastic deformation zone (8) protrudes from the central portion (13) of the sleeve (5).

4. The method according to any one of claims 1 to 3, wherein: The contact pin (6) has a foot (9) arranged at a proximal end of the contact pin (6), wherein the foot (9) protrudes from a central portion of the contact pin (6), wherein the foot (9) extends perpendicularly to a longitudinal axis (Y) of the contact pin (6).

5. The method according to any one of claims 1 to 3, wherein: The sleeve (5) has a protruding portion (12) arranged at the proximal end of the sleeve (5), wherein the protruding portion (12) protrudes from a central portion (13) of the sleeve (5), wherein the protruding portion (12) extends perpendicularly to the longitudinal axis (Y) of the contact pin (6).

6. A semiconductor power module (10), comprising the following items: - one or more semiconductors (4), the one or more semiconductors being located on a substrate (7); - a contact formed by a contact pin (6) provided with a plastic sleeve (5) having a central portion (13), wherein the contact pin (6) has a longitudinal axis (Y), characterized in that The plastic sleeve (5) encloses a portion of the contact pin (6), and a distal portion of the sleeve (5) comprises a plastic deformation zone (8), wherein the sleeve (5) encloses a portion of the contact pin (6), wherein the sleeve (5) is continuous from its distal portion to its proximal portion, and a) the proximal portion is in direct contact with the substrate (7), or b) a structure in direct contact with the substrate (7), wherein the structure is a foot arranged at the proximal end of the contact pin; wherein the sleeve (5) is suitable for transmitting a force along the longitudinal axis to the substrate (7) or a structure in direct contact with the substrate (7), wherein the force is large enough to cause the plastic deformation zone (8) to plastically deform.

7. The semiconductor power module (10) according to claim 6, wherein: The contact pin (6) has a foot (9), the width (L6) of the foot being greater than the width (L1) of the distal portion of the contact pin (6).

8. The semiconductor power module (10) according to claim 6 or 7, wherein: The sleeve (5) has a protruding portion (12) arranged at a proximal end of the sleeve (5), wherein the protruding portion (12) protrudes from a central portion (13) of the sleeve (5), wherein the protruding portion (12) extends perpendicularly to a longitudinal axis (Y) of the contact pin (6).

9. The semiconductor power module (10) according to any one of claims 6 or 7, wherein: The plastically deformed zone (8) protrudes from a central portion (13) of the sleeve (5).

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