Semiconductor power module and method for producing semiconductor module

Abstract

The semiconductor power module includes: one or more semiconductors placed on a substrate having a conductive layer; a housing made of a molding material that encapsulates at least the substrate and the semiconductor; at least one receptacle having a receptacle base mounted on the substrate and configured to receive and hold the pin connector in a substantially upright position perpendicular to the substrate through a hollow space in a receptacle handle defining an upright direction; and at least one sealing ring arranged around the socket handle and resting on the socket base. The sealing ring is fixedly held in an elastically deformed state by the molding material against the socket base in an upright direction, and seals the socket handle during a molding step of the housing to prevent the molding material from entering the hollow space such that the hollow space provides an opening on an outer surface of the housing.

Description

Technical Field

[0001] This invention relates to semiconductor power modules and methods for manufacturing semiconductor power modules. Background Technology

[0002] Frame-type and molded power modules are known in the field of power electronics. Such semiconductor power modules have semiconductor components, such as semiconductor diodes, transistors, thyristors, rectifiers, and switches, for example, in the form of IGBTs or MOSFETs. These components can utilize silicon-based semiconductors, or increasingly common wide-bandgap semiconductors, such as silicon carbide (SiC) or gallium nitride (GaN)-based semiconductors. In power modules, it is well known to use load and control pins that protrude from the housing.

[0003] For power modules operating at high switching frequencies, especially when using wide-bandgap semiconductor technology, it is important that the contact pins extend the shortest possible distance when connecting components and control electronics or loads. However, molded power modules with prominent contact pins are rare because the necessary manufacturing steps are difficult to perform.

[0004] Such contact pins are attached to the substrate prior to molding. For the molding step or process to be performed, it is necessary to attach sealing elements, which are securely or semi-permanently connected to the contact pins. These sealing elements must be attached to the contact pins before they are attached to the substrate so that they can reliably perform their sealing function.

[0005] One drawback of existing solutions is that a sealing element must be attached to the contact pins before they can be attached to the substrate. Therefore, ultrasonic welding of the contact pins is difficult and requires sophisticated tools. Consequently, methods for attaching contact pins to the substrate, such as welding or gluing, are rarely used because they are complex and expensive. If the sealing element is installed after the contact pins have been attached (as with existing solutions), the sealing element does not apply any pressure to the sealing profile of the pin shaft and the opening in the upper mold. This can cause the molding compound to potentially seep into the upper mold portion or the opening in the upper mold during molding and cause molding compound overflow, thus leading to contamination of the mold and / or the contact pins, which is an undesirable result.

[0006] Furthermore, in the molding process according to the prior art, the manufacturing cost increases in order to form reliable contact pins and prevent molding compound overflow, and it becomes less flexible due to the provision of specific contact pins and specific molds.

[0007] Therefore, there is a need for a semiconductor power module that does not have the aforementioned drawbacks of the prior art. Summary of the Invention

[0008] Therefore, an object of the present invention is to provide an improved method for manufacturing semiconductor power modules, wherein a sufficiently tight seal can be generated in the openings of the upper molding die or upper half mold to prevent spillage of molding compound and / or contamination of contact pins, while enhancing the flexibility of contact pin configuration without increasing manufacturing costs. The improved manufacturing process should enable a simple, flexible, robust, and cost-effective manufacturing process for semiconductor power modules with high reproducibility. Another object is to provide a semiconductor power module that can be manufactured without the aforementioned disadvantages.

[0009] The problem of the present invention is solved by means of the semiconductor power module and method described below.

[0010] The semiconductor power module according to the invention comprises: one or more semiconductors disposed on a substrate having a conductive layer; a housing made of molding material that at least encapsulates the substrate and the semiconductors; at least one socket having a socket base mounted on the substrate and configured to receive and retain a pin connector in a substantially upright position perpendicular to the substrate via a hollow space in a socket handle defining an upright direction; and at least one sealing ring disposed around the socket handle and resting on the socket base. The sealing ring is held in an elastically deformed state by the molding material abutting against the socket base in the upright direction and seals the socket handle during the molding step of the housing to prevent the molding material from entering the hollow space, such that the hollow space provides an opening on the outer surface of the housing.

[0011] The substrate on which one or more semiconductors are disposed according to the present invention can be a direct copper bond (DCB) substrate, such as SiC, AlN ceramics, etc. The use of DCB ceramics may be advantageous because of their good thermal conductivity. As is known in the art, various types of semiconductor devices, such as semiconductor diodes, transistors, thyristors, or switches, can be mounted on such semiconductor DCB ceramics.

[0012] Both the DCB substrate and the semiconductor components can be electrically contacted laterally (i.e., substantially parallel to the main extension direction of the substrate) outside the power module via electrical contact pins or terminals. According to the invention, at least one additional socket extends substantially vertically (i.e., at a right angle or approximately 90° relative to the substrate) and is exposed outside or protruding from the power module, having a connection portion on a side parallel to the substrate. This vertical socket is electrically connected to the substrate or at least electrically connected to a semiconductor disposed on the substrate. In a further description of the invention, any orientation or shape of the socket is covered by the term "vertical socket," even if the socket has an S-shape, as long as the connection area of ​​the socket is exposed from the encapsulation compound on the top or bottom side of the power module or the housing of the power module.

[0013] Vertical sockets can be attached to a substrate via their socket base by brazing, ultrasonic welding, laser welding, gluing, sintering, or press-fitting. In one embodiment, the socket can be a press-fit socket that can be inserted into a hole in a substrate (such as a printed circuit board (PCB), another example of a DCB substrate according to the invention). In one embodiment, the socket can have a hole or threaded hole formed in the socket base connected to the substrate by a threaded connection to electrically connect the socket and secure it to the substrate.

[0014] Preferably, after the vertical socket is secured to the substrate or semiconductor, a sealing ring and a washer are attached to the socket handle of the socket, such that the sealing ring elastically deforms when the mold is closed to at least partially surround one or more semiconductors, the substrate, and the socket. The mold typically consists of two halves, whereby the substrate, one or more semiconductors, and the socket are initially placed in the first (lower) half. In this state, the vertical socket does not protrude beyond the parting surface of the mold at its end. The sealing ring and washer are arranged to protrude slightly beyond the parting surface, such that the sealing ring elastically deforms when the second half is placed on top of the first half to seal the cavity at the parting surface. Thus, the arrangement of the sealing ring and washer securely holds the sealing ring and washer on the socket. In this state, the remaining cavity of the molding die is ready to be filled with a molding compound to at least partially surround and encapsulate the substrate, one or more semiconductors, and the socket.

[0015] In the end region of the receptacle handle remote from the substrate, the mold may include a flat surface that contacts and rests flat on the sealing ring or washer to seal the area above the receptacle handle. In this case, the receptacle handle does not protrude beyond the encapsulation compound. Otherwise, the receptacle handle would be squeezed or curled by the mold. However, the receptacle handle may also be flush with the encapsulation compound, allowing the mold to contact the receptacle handle. However, in this case, a lower contact force is required. Otherwise, the receptacle handle and / or the circuit board, semiconductor, and / or even the substrate may be damaged or degraded.

[0016] When the mold seals the area above the socket handle, the molding compound does not reach this area, and the end surface of the socket handle is not embedded in the molding compound but exposed to the outside. Therefore, after the packaged power module is removed from the mold, the end face of the socket handle is exposed. During manufacturing, when the upper mold is placed on the parting surface of the lower mold to close the cavity, the mold is pressed against a gasket, and the gasket applies compressive force to cause the sealing ring to elastically deform in the direction of the socket axis. In this closed state of the mold, the molding compound / molding material can fill the cavity of the mold while the sealing ring remains deformed according to the invention.

[0017] Due to the elastic axial deformation of the sealing ring, the restoring force of the sealing ring generates a good sealing force in the axial direction. Using this sealing force, the gasket is pressed against the inner surface of the upper mold, and the sealing ring seals the underside of the gasket and, on the underside, the socket base, or, if the socket base does not provide a suitable sealing surface, a second gasket. These elastic restoring forces of the sealing ring must be maintained at least until the molding compound / sealing compound hardens. Once the molding compound hardens, the gasket is surrounded by the molding compound / sealing compound and firmly held in place. In this state, the hardened molding compound is solid and no longer flows, meaning it cannot contaminate the connection end, which serves as the end surface of the socket handle. Additionally, the hollow space formed in the socket handle is exposed to the outside of the molding compound. The hollow space can have a circular, elliptical, or rectangular cross-section.

[0018] The upper mold may also not include a flat surface. In this case, only the lower surface of the upper mold needs to contact the gasket or sealing ring accordingly. If such contact is formed, the end surface of the socket handle is protected against penetration of the molding compound. Furthermore, in this case, the socket handle may protrude from the encapsulating compound. For example, the protruding socket handle can be accommodated in a recess formed in the mold.

[0019] According to the invention, during the packaging process of semiconductors, substrates, and sockets, the sealing ring is also fixed radially outward by a molding compound. Once the molding component hardens, the gasket and sealing ring no longer move or expand along the socket axis. Therefore, when the molding compound hardens, the sealing ring remains in its elastic deformation state.

[0020] In one embodiment of the invention, a resiliently deformable / compressible sealing ring in the axial direction of the socket seals the gasket and also seals the socket axis on its inner side, such that no molding compound can flow along the socket axis and penetrate onto the top of the socket handle when the mold is filled. This means that the molding material will not contaminate the end of the vertical socket; in other words, the end surface of the socket handle and the hollow space formed in the socket handle are substantially free of molding material. In the compressed / deformed state, the sealing ring flattens in its axial direction while expanding in the radial direction. Although the sealing ring in this embodiment also seals with the socket handle due to the radial expansion of the sealing ring, this feature is not essential to the invention, as the axial sealing contact of the sealing ring on both the top and bottom sides is sufficient to prevent molding compound from penetrating onto the end surface and hollow space of the socket handle.

[0021] Because the sealing ring elastically deforms and abuts against the base of the socket, against the gasket, or against both gaskets in the case of a sandwiched receiving portion, and because the upper gasket is pressed downward toward the socket handle by closing the second half of the mold, all radial paths of the molding compound penetrating toward the socket handle are sealed, so that no molding compound can reach the socket handle and cause the socket handle to rise and contaminate the connection end.

[0022] In a preferred embodiment, the sealing ring rests on the base of the socket, requiring only a washer to rest on the sealing ring such that when the mold closes, the washer is pressed down, causing the sealing ring to elastically deform against the base of the socket. If the cross-section of the socket base is smaller than the radial range of the required support diameter of the sealing ring, or even smaller than the opening in the sealing ring, the sealing ring will rest on the substrate or semiconductor or other component of the power module. Although this is not a preferred embodiment, it is covered by the inventive concept because the solution is feasible as long as the substrate or other components of the power module are not damaged by the force causing the sealing ring to elastically deform, and as long as no short circuit, current leakage, impedance, or other parasitic current occurs due to direct contact between the sealing ring and adjacent components.

[0023] Those skilled in the art will recognize that, according to the invention, the sealing ring and washer can also be applied to the socket in reverse order, i.e., the washer contacts the base of the socket and the sealing ring contacts the lower inner surface of the upper half of the mold. In this embodiment, when the mold is closed, the upper half of the mold directly causes the sealing ring to elastically deform. In this case, the sealing ring will be visible on the top of the finished power module. However, in this state, the molding material cures and there is no contamination of the socket handle through the molding material, thus also obtaining a power module according to the invention.

[0024] In another preferred embodiment of the invention, the sealing ring is sandwiched between two washers, thereby being securely fixed in the closed mold and also in the power module in the deformed state, thus achieving a seal by the two washers and possibly by the socket handle. This embodiment is more advantageous if the radial extension or support surface of the socket base is too small to be suitable for direct sealing with the sealing ring (i.e., if the support surface of the socket base is too small to ensure reliable elastic deformation of the sealing ring without damaging the sealing ring or components arranged on the substrate or damaging the coated / printed circuitry). If there is a risk of the sealing ring or washer contacting the applied circuitry on the substrate, it is preferable that the lower washer contacting the circuitry and / or the socket base is made of a non-conductive material to prevent short circuits, current leakage, impedance, inductance, or other parasitic currents.

[0025] The sealing ring is preferably made of a natural or synthetic elastomer or elastically deformable silicone material, so that, at least during the molding / sealing step, the sealing ring can maintain a sealing contact with the gasket and / or the second half of the mold due to internal restoring forces, thereby at least partially surrounding / encapsulating the substrate, one or more semiconductors, and the socket. Since the sealing ring according to the invention does not need to perform any function other than sealing the underside of the gasket, the socket base, and / or the upper mold, it is preferably a standard part, readily and inexpensively available. Since one or more gaskets according to the invention do not need to perform any other function besides providing an axial surface that can seal under pressure with another flat surface or the sealing ring, one or more gaskets can also be selected as commercially available standardized parts. Standardized gaskets are available in a wide variety of diameters and thicknesses. Thicker gaskets are also called spacer gaskets or simply spacers. Therefore, according to the invention, all these variations of the gasket can be used together with the deformed sealing ring to bridge the gap between the socket base or substrate and the top exterior of the power module housing. In other words, the height of the gasket should be selected such that the length of the sealing ring and the package of one or two gaskets, when placed on the base of the socket, is greater than the amount of elastic deformation of the sealing ring when the two half-molds are joined together. The elastic deformation of the sealing ring should be large enough that the restoring force of the deformed sealing ring is high enough to ensure good sealing pressure, which is high enough to prevent radial penetration of liquid molding material between the base of the socket and the sealing ring or gasket, or between the sealing ring and the gasket, or between the gasket and the lower inner surface of the upper half-mold.

[0026] Furthermore, according to the invention, at least one or both washers are made of metal, plastic, reinforced plastic, ceramic, or elastic material, depending on economic or technical reasons / requirements, in order to prevent short circuits, current leakage, inductance, or other parasitic currents. It should be noted that the washers can be conductive or electrically insulating, and the materials can be metallic, organic, inorganic, or a combination of these materials.

[0027] According to the invention, the cross-section of the socket and the socket handle (which is perpendicular or substantially perpendicular to the substrate) can have any shape, preferably circular, elliptical, or rectangular. Corresponding to the cross-section of the socket handle, the sealing ring or the opening in the sealing ring has a suitable shape to surround the socket handle. One or more washers do not necessarily have to have the same external or internal shape as the sealing ring, because the sealing ring seals with the washers primarily in the axial direction (i.e., in the direction of the socket axis).

[0028] In another embodiment of the invention, more than one upper contact or more than one lower contact may be led outward through a socket perpendicular to the substrate and connected to the electrical components of the power module. In all these cases, according to the invention, each socket may be led outward individually, i.e., a sealing ring and at least one gasket may be arranged on each socket such that during the encapsulation step of the power module, no liquid molding compound travels / flows along the socket and contaminates the connection end of the socket.

[0029] When the power module is designed to have a lower contact parallel to the upper contact, the concept according to the invention can be applied in a similar manner, except that when the second half-mold is placed on the parting surface, the substrate in the first half-mold is pushed into its final vertical position.

[0030] In another embodiment of the power module according to the invention, more than one socket arranged vertically on the substrate can be sealed so that their connection ends are not contaminated by molding compound. Each socket may respectively accommodate a sealing ring and at least one washer, or possibly an elliptical sealing ring and at least one washer may surround all socket handles. This is particularly effective when two or more sockets have the same potential and can reduce the number of components required to assemble the power module. Those skilled in the art will likely use a solution here in which a (possibly elliptical or rectangular) sealing ring is sandwiched between two (possibly elliptical or rectangular) washers. Those skilled in the art will also discover other ways to reduce the number of components in order to complete a power module according to the invention having more than one upper or lower contact. Thus, all these solutions are covered by the concept of the invention.

[0031] Furthermore, the socket can be of the press-fit type. This means that the socket provides a press-fit connection to the outside. According to the invention, the socket is exposed to the outside of the encapsulating compound. A press-fit connection is provided at this exposed portion of the socket. For example, at this exposed portion, the socket includes a recess or opening (both referred to as a hollow space) that is centered along and relative to the axial direction of the socket or socket handle. Thus, the cross-section along the axial direction can be U-shaped, or appear to be an inverted "pi" shape. The hollow space can have any shape, and the hollow space does not necessarily need to be aligned with the central axis of the socket. The cross-section of the hollow space in the radial direction can be circular, rectangular, elliptical, or any other shape. Thus, mating terminals can be inserted into and press-fitted into the hollow space of the socket. The mating terminals can have different cross-sectional shapes to enhance the press-fit connection.

[0032] Using the socket according to the invention, flexible connection to the outside can be achieved through a press-fit connection suitable for the respective application. Furthermore, if the socket stem does not protrude from the encapsulation compound, the molding die can be the same for different connection schemes. For example, if the socket protrudes from the encapsulation compound, the molding die will need to accommodate a recess in the socket to prevent compression or crimping of the socket when two molding dies come into contact. However, the molding die according to one embodiment of the invention can have a flat surface. Therefore, different arrangements of the socket can be achieved while still using the same molding die. This results in reduced manufacturing costs because the power module does not require a separate molding die for manufacturing.

[0033] Furthermore, the flat surface allows for better stacking and packaging of power modules, preventing damage to protruding connectors on at least one surface. This benefits transportation and the use of multiple power modules arranged in a stack. Interconnection between two power modules can be achieved, for example, by using pins with two press-fit terminals.

[0034] Furthermore, the socket configuration can be easily changed and varied throughout different implementations. This enhances the flexibility and personalization for both manufacturers and consumers. Additionally, specific terminals can be supplied without compromising reliability during manufacturing.

[0035] It should be noted that the power module is connected to the upstream system by connecting the exposed power module terminals. The difference between the prior art and the present invention is that the prior art provides at least one protruding terminal, while the present invention provides at least one press-fit terminal. By using a press-fit terminal, press-fit pins or press-fit pin-type contact pins can be inserted into the hollow space of the socket after the molding process, thereby forming a protruding terminal. As a result, after the molding process, the press-fit terminal is changed to a protruding terminal, so that the power module received by the consumer has the same terminals as in the prior art.

[0036] Furthermore, the present invention provides a method for manufacturing a semiconductor power module having one or more semiconductors disposed on a substrate having a conductive layer, wherein the substrate and the semiconductors are at least partially covered by a housing formed of a molding material, wherein at least one opening in the housing is configured for electrical contact with the conductive layer. The method includes the following steps: providing a substrate having a conductive layer and one or more semiconductors disposed thereon; fixing at least one socket having a socket base to the conductive layer such that a socket handle extends perpendicularly to the substrate; placing a sealing ring on the socket handle such that the sealing ring rests on the socket base; placing the substrate having the socket and the sealing ring in a first half-mold; closing the first half-mold in an upright direction parallel to the socket handle by means of a second half-mold, thereby elastically deforming the sealing ring by pressing it against the socket base by means of the second half-mold, such that the second half-mold closes the hollow space of the socket, wherein the sealing ring seals the socket handle to prevent molding material from entering the hollow space; filling the cavity of the mold with the molding material; opening the mold after the molding material has cured; and removing the semiconductor power module from the mold. Attached Figure Description

[0037] Referring to the accompanying drawings, preferred embodiments of the power module according to the invention will be explained in more detail to better understand the basic concept of the invention. The embodiments of the invention do not limit the scope of the inventive concept, but only represent possible alternative embodiments, which can be modified within the knowledge of those skilled in the art without departing from the scope of the invention. Therefore, all such modifications and variations are covered by the claimed invention. The accompanying drawings show:

[0038] Figure 1 This is a first embodiment of the power module according to the present invention, prior to the closing of the molding die;

[0039] Figure 2 yes Figure 1 The power module, in which the molding die is closed;

[0040] Figure 3 It is taken out of the molding die. Figure 1 The power module;

[0041] Figure 4 This is a second embodiment of the power module according to the present invention;

[0042] Figure 5 This is a third embodiment of the power module according to the present invention;

[0043] Figure 6 This is a fourth embodiment of the power module according to the present invention;

[0044] Figure 7 This is the fifth embodiment of the power module according to the present invention;

[0045] Figure 8a and Figure 8b These are possible embodiments of a socket, and a cross-section of the socket and its corresponding contact pins;

[0046] Figure 9a and Figure 9b This is a possible embodiment of the socket;

[0047] Figure 10 It is a power module, in which contact pins are assembled in a socket; and

[0048] Figure 11 This is a schematic flowchart of a method for manufacturing a power module according to the present invention.

[0049] For better traceability and to improve readability of the detailed description, the same reference numerals are used throughout the drawings to indicate equivalent parts or elements that have the same function.

[0050] Even though indications of up and down orientation and position are given, they only refer to the orientation of the elements shown in the figures and do not necessarily coincide with the orientation and position in normal use of the power module according to the invention. Thus, for example, the top contact shown in the figures may be oriented towards the bottom or side in normal use of the power module according to the invention. Indications regarding top or bottom are only for enhancing the understanding and readability of the figures and their description, and are derived from the typical positioning of the encapsulation mold and the half-mold used. Detailed Implementation

[0051] Figure 1 A first embodiment of an unencapsulated semiconductor power module 1 (also referred to as power module 1) according to the invention is shown, placed in an open molding die or open packaging die 20, i.e., just before the packaging die 20 is closed to perform a packaging step, wherein a substrate 7, on which a bonding layer or conductive layer 9 is applied, one or more semiconductors 4 connected to the bonding layer / conductive layer 9, and a socket 60 projecting substantially perpendicularly to the substrate 7 are at least partially encapsulated by a molding compound (also referred to as an encapsulation compound or molding material) using the packaging step. The vertical socket 60 is secured to, for example, the conductive layer 9 via a socket base 61 by any known securing process, such as soldering, ultrasonic welding, laser welding, bonding, sintering, or by press fitting. The invention also covers socket 60 positioned and secured by its socket base 61 to any other component arranged in the power module 1, such as socket 60 bonded to semiconductor 4 via its socket base 61.

[0052] Furthermore, regarding the present invention and Figure 1In the exemplary embodiment shown, after the socket 60 is fixed to the substrate, bonding layer or conductive layer 9 or fixed to the semiconductor 4, the gasket 8 and sealing ring 5 are received by the socket handle 62 of the socket 60, such that the sealing ring 5 contacts the socket base 61. This (pre)assembly assembly, consisting of the substrate 7 having the bonding or conductive layer 9, the semiconductor 4, and the socket 60 having the gasket 8 and sealing ring 5, is placed in the first lower half mold 21 such that the socket handle 62 and its socket handle end 65 are upright.

[0053] The socket handle 62 is a protrusion extending from the socket base 61 and includes a hollow space 63 along the socket handle axis 64. A cross-section along the axial direction of the socket handle 62 shows two parallel protrusions clamping the free space. The free space is a hollow space 63 that can have a 3D tubular shape. The hollow space 63 is recessed from the socket handle end 65 toward the socket base 61. The direction toward the socket base 62 is a downward direction, and the opposite direction is an upward direction 11. Thus, the hollow space 63 is formed by the socket base 61 in the upward direction 11. The hollow space 63 can completely or partially pass through the socket handle 62. In a radial cross-section of the socket handle 62, the hollow space 63 can have any shape and can be circular, rectangular, or elliptical. The hollow space 63 can be aligned with the central axis of the socket handle 62, but this is not required. The hollow space 63 is exposed to the outside of the housing 15 after the molding process of the housing 15. Therefore, the hollow space 63 forms an opening on the outside of the shell 15.

[0054] like Figure 1 As can be seen, the first lower mold half 21 includes a mold separation line or parting surface 24 at its upper end. The first lower mold half 21 and the second lower mold half 22 can be connected together here to tightly seal the cavity 23 of the mold 20. When the mold 20 is closed, the encapsulating or molding material 10 (see...) Figure 3 The encapsulation material 10 can be filled into the cavity 23 through the mold inlet 25. After the encapsulation material 10 has cured, the completed power module 1 can be removed from the lower mold 21 after the second upper mold 22 is removed. Figure 3 The following is shown after removal from the packaging mold 20: Figure 1 and Figure 2 The power module 1 has a housing 15 formed by an encapsulating compound or encapsulating material 10. Therefore, the housing 15 also corresponds to the encapsulation of the power module 1. However, an outer shell may be additionally provided on the housing 15.

[0055] from Figure 1It can be further seen that, in the open state of the encapsulation mold 20, the socket handle end 65 of the socket 60 does not protrude vertically beyond the parting surface 24, wherein at least a portion of the gasket 8, received on the socket handle 62 and supported by the sealing ring 5, protrudes vertically beyond the parting surface 24, and wherein the sealing ring 5 is in an undeformed state, wherein the cross-section of the sealing ring 5 shows a circular, substantially circular form. According to the invention, the upper mold 22 includes a substantially flat surface 3 on the side facing the cavity 23, and when the second upper mold 22 directly contacts the first lower mold 21 (i.e., when the encapsulation mold 20 is closed and ready for the encapsulation step), the surface 3 is configured to contact at least a portion of the gasket 8 protruding from the parting surface 24 (see also) Figure 2 ).

[0056] When the second upper half mold 22 (as from) Figure 1 When the washer 8 (as indicated by arrow 26) is placed on the lower mold half 21, it is pushed downwards into the cavity 23 of the mold 20 along the axis of the socket handle 62 (i.e., the longitudinal direction of the socket handle 62). Thus, according to the invention, the sealing ring 5, which rests statically on the socket base 61, elastically deforms and expands radially in the axial or vertical direction. In this state, the sealing ring 5 exhibits a more or less elliptical cross-section, such as... Figure 2 As can be seen in the text. Figure 2 The final deformed state of the sealing ring 5 in the (fully) closed encapsulation mold 20 is shown. At this point, according to the invention, the cavity 23 of the mold 20 can be filled with encapsulation material 10 via the mold inlet 25 to at least partially encapsulate the substrate 7, one or more semiconductors 4, and vertical socket 60 together with the elastically deformed sealing ring 5 and the undeformed gasket 8.

[0057] In such Figure 2In the illustrated case, the sealing ring 5 is forced to deform into an elastically deformed state in the direction of the socket handle axis 64, thereby providing a sealing force from the sealing ring material upwards onto the washer 8 and downwards onto the socket base 61 in the axial direction of the sealing ring 5. The washer 8 is pushed upwards by the elastic restoring force of the deformed sealing ring 5 and presses against the lower mold surface of the second upper mold 22 and the cavity limiting surface 27. This upward elastic force creates a sealing effect between the washer 8 and the cavity limiting surface 27 to prevent the molding material 10 from flowing toward the socket handle 62 or the upper end surface of the socket handle 62 during the molding step. Such undesirable material flow would result in contamination of the socket handle end 65 of the socket 60. Due to the elastic restoring force of the sealing ring 5 in the axial direction (i.e., in the direction of the socket handle 62), this passage, as well as all other possible passages through which the molding material 10 reaches the socket handle 62 in the radial direction and climbs upwards along the socket handle 62, is actively sealed by the elastic restoring force of the deformed sealing ring 5. These elastic restoring forces provide sealing contact between the washer 8 and the mold 20, the washer 8 and the sealing ring 5, and the sealing ring 5 and the socket base 61, at least in the axial / vertical direction.

[0058] In such Figures 1 to 3 In the first exemplary embodiment shown, the sealing ring 5 elastically deforms such that its cross-section forms an ellipse due to compression in the axial direction and expands in the radial direction (away from and toward the socket handle 62). This expansion toward the socket handle 62 can be used to achieve further sealing contact between the deformed sealing ring 5 and the socket handle 62. However, as described above, an axially oriented seal is generally sufficient to prevent fluid molding material from flowing toward and upward along the socket handle 62 during the molding step, thus contaminating the socket handle end 65.

[0059] Figure 3 The diagram illustrates a power module 1 according to the present invention, having a top contact, i.e., the socket handle end 65 with a hollow space 63 is not encapsulated by the encapsulation material 10 and is encapsulated by the encapsulation material 10 forming the housing 15 of the power module 1. The power module 1 shown can be contacted on one side substantially parallel to the substrate 7. Electrical connection can be made by inserting contact pins 70 into the hollow space 3 and / or by attaching contact pins 70 to the end surface of the socket handle 62. As deduced by those skilled in the art, when using a power module, either side can be used as the power module, but it must not be one side. Figure 3 The top side is shown. As those skilled in the art will also appreciate, the illustrated embodiment for the power module will have at least one or more additional contact terminals, for example, in the direction of the plane of substrate 7 ( Figure 3 It protrudes in the horizontal direction (of the middle). In this respect, Figures 1 to 3The embodiments shown are simplified examples to illustrate the basic concept of the invention.

[0060] As in Figures 1 to 3 As can be seen from the figures, the power module 1 according to the invention can be manufactured using one type of molding die. However, as can be appreciated from the figures, the same molding die can be used if the socket 60 is placed in different locations because the socket 60 does not protrude from the parting surface 24. Electrical connection to the outside of the power module is made through the hollow space 63 in the socket handle 62. Therefore, since the molding die can be used for various configurations of the socket 60, manufacturing costs are reduced.

[0061] It should be noted that the invention is still feasible if the socket 60 passes through the parting surface 24; however, in this case, the molding die must be changed to a different construction. Similarly, in this case, the contact pin 70 can be connected to the socket 60 by inserting the contact pin 70 into the hollow space 63.

[0062] exist Figure 4 The image shows another embodiment of the concept according to the present invention. Figure 4 The embodiment of power module 1 and Figure 1-3 The illustrated embodiment differs in that the sealing ring 5 is sandwiched between two washers 8. This is preferable, particularly when the support surface of the socket base 61 supporting the sealing ring 5 is not large enough to ensure proper deformation of the sealing ring 5 as it deforms through the closing mold 20 (and therefore not achieves a sufficiently high elastic restoring force to provide a sealing contact in the radial direction so that no encapsulating material can enter between the cavity limiting surface 27, the washers 8, the sealing ring 5, and the socket base 61). Figure 2 As can be seen, if the second lower washer 8 were not present, the sealing ring 5 would slide above the socket base 61 when pushed downwards. Therefore, the height of the socket base 61 would limit the elastic deformation and restoring force of the sealing ring 5 to ensure a good seal between the cavity limiting surface 27, the washer 8, the sealing ring 5, and the socket base 61. Thus, the second lower washer 8 is provided to rest on the socket base 61 and to provide support against deformation of the sealing ring 5 when the encapsulation mold is closed to perform the encapsulation step.

[0063] Therefore, when the radial extension of the socket base 61 is small or when press-fit pins are used, Figure 4 The solutions shown in the embodiments are particularly preferred. For example, those skilled in the art will... Figure 4The derivation of gaskets covering or surrounding the base of the socket, such as sleeves, and providing a supporting surface for the sealing ring 5, are all within the scope of this invention, even if not shown in the figures. The invention also covers the possibility that, independent of the illustrated embodiment, the gasket 8 may include a circumferential sealing groove, similar to sealing grooves known in the art, at least on the side facing the sealing ring 5. The invention may also cover the use of three or more gaskets, for example, to adapt the height of the gasket / sealing ring package to the height of the socket handle. It is also contemplated herein to use two sealing rings 5 ​​and three gaskets 8, one on top of the other, alternating such that each sealing ring 5 is sandwiched between two gaskets 8. Those skilled in the art will find numerous possibilities in which the package fills the space between the socket base 61 and the socket handle end 65 of the socket 60, such that at least one sealing ring 5 elastically deforms when the encapsulation mold 20 is closed. Since all these embodiments of the invention are within the knowledge of those skilled in the art, it is unnecessary to describe these possibilities further.

[0064] Figure 5 Another embodiment of the invention is shown, from which it can be deduced that the invention also covers a power module 1 having more than one socket 60 protruding substantially perpendicular to the substrate 70. Figure 5 In the embodiments shown, an embodiment with two sockets 60 is illustrated, representing an embodiment of all power modules 1 according to the invention having more than one socket 60 protruding perpendicularly to the substrate 7. As those skilled in the art will appreciate, arranging and fixing two or more vertical sockets 60 on the substrate 7 or on one or more semiconductors 4 is merely a design issue. Depending on the number of vertical sockets 60, if none of the sockets 60 protrude beyond the parting surface 24 of the packaging mold, the upper mold 22 still has a flat surface. In another case, the upper mold 22 must have a recess for each socket 60 protruding from the parting surface 24 at a corresponding location, so that these sockets 60 are not damaged when the mold is closed.

[0065] pass Figure 6 This illustrates another possibility for realizing the concept of the invention, wherein the two washers 8 are configured as a perforated plate having a number of holes equal to the number of sockets 60, which should be guided to the outside of the housing without molding material or exposed to the outside of the power module 1. A sealing ring 5 is sandwiched between the two washers 8, and the sealing ring 5 elastically deforms when the encapsulation mold 20 is closed. Here, the sealing ring can be formed as an O-ring, including circular, elliptical, or rectangular shapes, from which the external form of the socket handle 62 can be replicated. Furthermore, the upper washer 8 is not necessarily a perforated plate, as it can also have, for example, more than one elongated hole through which the socket handle 62 can pass. According to the invention, molding material must be prevented from entering the area between the two socket handles 62. Figure 6As shown in the embodiment, this is achieved by elastically deforming the sealing ring 5 to press the lower washer 8 onto the socket base 61. As will be apparent to those skilled in the art, the sealing ring 5 can also be an elastically deformable disc to transmit sealing force in the longitudinal direction of the socket handle axis. It will also be readily apparent to those skilled in the art that the two washers 8 and the sealing ring 5 sandwiched therebetween can receive / enclose more than two sockets 60. Figure 6 The socket handles 62 indicated by the socket 60 are represented by dashed lines.

[0066] Figure 7 Another embodiment of the invention, suitable for power module 1, is shown, wherein the socket 60 protrudes vertically on both sides of the substrate 7, i.e., vertically on the upper and lower sides, as shown. Figure 7 As shown. Here, it must be considered that if the socket 60 protrudes beyond the parting surface 24, one or more sockets 60 designed to be accessible via their socket handle end 65, flush with or protruding from the cured encapsulation material, would require corresponding recesses in the lower mold half 21. However, here, the socket 60 is designed not to protrude beyond the parting surface 24, and therefore, no recesses are needed in the molding die. Furthermore, it must be considered that the unencapsulated power module 1 must be pushed downwards to elastically compress the sealing ring 5 received on the downward-facing socket 60. For this purpose, multiple support ribs can be arranged in the lower mold half 21 of the encapsulation mold 20 to limit the deformation of the sealing ring 5 and prevent damage to the substrate 7 and its components. During the placement of the upper mold half 22 on the parting surface 24, the downward movement of the substrate 7 and its attached components can be similar to the aforementioned embodiment, while deforming all the sealing rings 5. Of course, this is only one of many possible solutions known to those skilled in the art. Figure 7 The embodiments described are for illustrative purposes only, and the invention is not limited to the embodiments provided.

[0067] The power module 1 according to the invention and the method of manufacturing it having one or more socket handle ends 65 protruding only on one side perpendicular to the substrate 7 are also applicable to embodiments of the power module 1 having more than one socket handle end 65, regardless of whether the socket handle end 65 is exposed to the outside of the power module 1 only on one side or on two opposite sides (e.g., top and bottom sides).

[0068] exist Figure 8a In the diagram, socket 60 is shown as an example to represent a plurality of sockets that may be used in embodiments of the invention. Figure 8aThe socket 60 is shown to be rotationally symmetrical with respect to the socket handle axis 64 and to have a circular cross-section. The circular socket base 61 is preferably easily bonded to the bonding layer or conductive layer 9 on the substrate 7, for example, by ultrasonic or laser welding. Figure 8b The geometry is an example of the cross-section of the hollow shape 63 and the contact pin 70. The shape on the left is an example of the circular cross-section of the hollow space 63, and the shape on the right is an example of the rectangular cross-section of the contact pin 70. If the contact pin 70 with a rectangular shape is inserted into the hollow space 63 with a circular shape to provide an electrical connection to the outside of the power module 1, the two components are press-fitted due to their different shapes. Of course, those skilled in the art will determine the shape of the socket 60 and the shapes of the hollow space 63 and the contact pin 70 according to the corresponding application, and thus provide an appropriate configuration.

[0069] Figure 9a An embodiment of the invention is shown, wherein the socket 60 protrudes from the parting surface 24. As in... Figure 9a As can be seen, the upper mold includes a recess, as mentioned above. The socket 60, which protrudes from the parting surface 24, is received in the recess so that the socket 60 is not damaged when the upper mold 22 is placed on the lower mold 21. Figure 9b Shown after the molding process Figure 9a The power module 1 has a housing 15 and a protruding socket 60 with a hollow space 63.

[0070] Figure 10 A power module 1 including a socket 60 is shown, with contact pins 70 inserted into the socket 60, for example, by press-fit. Contact pins 70 are electrical pins, through which other electrical components, interconnects, wires, or connectors can be connected to provide an electrical connection to the interior of the power module 1. Contact pins 70 are adapted to the socket 60, or vice versa—and particularly adapted to the hollow space 63 of the socket 60 to form a secure and stable connection. However, a detachable connection can also be provided, for example, using a threaded hole as the hollow space 63 and using threads as the outer periphery of the contact pins 70.

[0071] Figure 11 A method for manufacturing a power module 1 and corresponding method steps are shown. In step S0, a substrate 7 is provided, wherein the substrate includes electronic devices, such as a conductive layer 9 and a semiconductor 4 (or at least one semiconductor 4). The conductive layer 9 and the semiconductor 4 are placed on and fixed to the substrate 7.

[0072] In step S1, a socket 60 (or at least one socket 60) comprising a socket base 61, a socket handle 62, and a hollow space 63 is fixed to the conductive layer 9. The socket 60 is fixed such that the socket handle 62 extends perpendicularly to the substrate 7.

[0073] In step S2, the sealing ring 5 is placed on the socket handle 62 such that the sealing ring 5 rests on the socket base 61. Optionally, at least one washer 8 may additionally be placed on the socket handle 62, as explained in some embodiments. It should be noted that the height of the sealing ring 5 and / or washer 8 is set such that the stack formed by the sealing ring 5 and the washer 8 placed on the socket handle 62 slightly extends through or protrudes from the parting surface 24, so that an axial force can be applied by closing the mold 20 (see step S4).

[0074] In step S3, the substrate 7, including the electronic components and the socket 60, is placed in the first half-mold 21. This is the first step of the packaging or molding process.

[0075] In step S4, the mold 20 is closed to form the cavity 23. The first half-mold 21 is closed by the second half-mold 22 in an upright direction 11 parallel to the socket handle 62. The seal 5 is elastically deformed by the second half-mold 22 (due to the intersection or protrusion of the sealing ring 5 or gasket 8 relative to the parting surface 24) pressing it against the socket base 61, such that the second half-mold 22 closes the hollow space 63 of the socket 60, wherein the sealing ring 5 seals the socket handle 62 to prevent the molding material 10 from entering the hollow space 63. The cavity limiting surface 27 is the surface that presses the sealing ring 5 and / or gasket 8 against the socket base 61, and the sealing of the socket handle end 65 and the hollow space 63 is ensured by the pressing force between the cavity limiting surface 27 and the sealing ring 5 and / or gasket 8.

[0076] In step S5, the cavity 23 formed in the mold 20 is filled with encapsulating or molding material 10. The molding material 10 may be, for example, a suitable resin having insulating properties.

[0077] In step S6, after the molding material 10 has cured, the mold 20 is opened so that the power module 1 can be removed from the mold 20. After the curing process, the molding material 10 forms the housing 15 of the power module 1, which can completely or partially encapsulate the substrate 7, electronic components, and socket 60. However, at least a portion or end surface (socket handle end 65) of the hollow space 63 and the socket handle 62 is exposed to the outside of the power module 1.

[0078] Therefore, the socket 60 and method according to the invention improve the ease of manufacturing the power module 1, ensure the reliability of the electrical connection, promote the flexibility of circuit configuration, and reduce manufacturing costs.

[0079] From the foregoing disclosure, the accompanying drawings, and the claims, it will be appreciated that the power module according to the invention and the method for manufacturing such a power module offer numerous possibilities and advantages over the prior art. Those skilled in the art will further appreciate that further modifications and alterations known in the art can be made to the power module according to the invention without departing from the spirit of the invention. Therefore, all such modifications and alterations are within the scope and are covered by the claims. It should also be understood that the above examples and embodiments are for illustrative purposes only, and various modifications, alterations, or combinations of embodiments according to the invention are included within the spirit and scope of this application, and such modifications, alterations, or combinations will be suggested by those skilled in the art.

[0080] List of reference numerals

[0081] 1 power module

[0082] 3. Flat surface

[0083] 4 Semiconductors

[0084] 5 sealing rings

[0085] 7 substrate

[0086] 8 washers

[0087] 9 conductive layers

[0088] 10 Molding / Encapsulation Compounds / Encapsulation Materials

[0089] 15 housing

[0090] 20 molds / molding dies

[0091] 21 First lower half mold

[0092] 22 Second upper half mold

[0093] 23 Molded cavities

[0094] 24 Mold separation lines / parting surfaces

[0095] 25 Mold Entrance

[0096] 26 Mold Closure Direction

[0097] 27 cavity confinement surface

[0098] 60 socket

[0099] 61 socket base

[0100] 62 socket handle

[0101] 63 hollow space

[0102] 64 socket handle axis

[0103] 65. End of the socket handle.

Claims

1. A semiconductor power module (1) comprising: - one or more semiconductors (4) placed on a substrate (7) having a conductive layer (9); - a housing (15) made of a molding material (10) encapsulating at least the substrate (7) and the semiconductors (4); - at least one socket (60) having a socket base (61) mounted on the substrate (7) and configured to receive and hold a pin connector in a substantially upright position perpendicular to the substrate (7) by a hollow space (63) in a socket handle (62) defining an upright direction (11); - at least one sealing ring (5) arranged around the socket handle (62) and resting on the socket base (61); characterized in that the sealing ring (5) is fixedly held by the molding material (10) against the socket base (61) in an elastically deformed state in the upright direction (11) and seals the socket handle (62) during the molding step of the housing (15) preventing the molding material (10) from entering into the hollow space (63) such that the hollow space (63) provides an opening on an outer surface of the housing (15).

2. The semiconductor power module (1) according to claim 1, characterized in that The socket handle (62) and / or the hollow space (63) show a circular, elliptical or rectangular cross section.

3. The semiconductor power module (1) according to claim 1 or 2, characterized in that The sealing ring (5) shows a circular, elliptical or rectangular shape which replicates the outer shape of the socket handle (62) and wherein the cross section of the sealing ring (5) is circular, elliptical, rectangular or any other shape.

4. The semiconductor power module (1) according to claim 1 or 2, characterized in that A grommet (8) fixedly holds the sealing ring (5) around the socket handle (62) by the molding material (10) of the housing (15) and the sealing ring (5) is pressed against the socket base (61) by the grommet (8) into an elastically deformed state in the upright direction (11).

5. The semiconductor power module (1) according to claim 4, characterized in that The grommet (8) shows a circular, elliptical or rectangular circumferential shape and a substantially rectangular cross section.

6. The semiconductor power module (1) according to claim 4, characterized in that The sealing ring (5) is sandwiched between two grommets (8) with one grommet resting on the socket base (61).

7. The semiconductor power module (1) according to claim 4, characterized in that The at least one grommet (8) or the two grommets (8) are made of metal, plastic, reinforced plastic, ceramic or an elastic material.

8. The semiconductor power module (1) according to claim 1 or 2, characterized in that The sealing ring (5) is made of an elastomer or silicone material.

9. The semiconductor power module (1) according to claim 1 or 2, characterized in that The socket base (61) is fixed to the substrate (7) by ultrasonic welding, laser welding, soldering, bonding, sintering or press fit.

10. The semiconductor power module (1) according to claim 1 or 2, characterized in that Two or more socket handles (62) are fixed on the substrate (7) next to each other with one grommet (8) resting on the at least one socket base (61) and one sealing ring (5) held in an elastically deformed state in the upright direction by a second grommet (8) in a sandwiched manner, wherein the grommets (8) and the sealing ring (5) both surround all socket handles (62).

11. The semiconductor power module (1) according to claim 1 or 2, characterized in that The hollow space (63) is configured to hold and receive a pin connector which is a contact pin (70) of a press-fit pin type configuration such that the contact pin (70) can be inserted and fixed in the hollow space (63) of the socket (60).

12. The semiconductor power module (1) according to claim 1 or 2, characterized in that A second socket (60) receives at least one sealing ring (5) and one gasket (8) thereon, said second socket (60) being arranged in a similar manner in the semiconductor power module (1) according to any one of the preceding claims, but with its hollow space (63) facing the opposite side of the substrate (7).

13. A method for manufacturing a semiconductor power module having one or more semiconductors (4) placed on a substrate (7) having an electrically conductive layer (9), characterized in that The substrate (7) and the semiconductor (4) are at least partially covered by a housing (15) formed from a molding material (10), wherein at least one opening in the housing (15) is provided for electrically contacting the conductive layer (9), the method comprising the following steps: a) providing (S0) a substrate (7) having a conductive layer (9) and one or more semiconductors (4) placed thereon; b) fixing (S1) at least one socket (60) having a socket base (61) on the conductive layer (9) such that a socket shank (62) extends perpendicular to the substrate (7); c) placing (S2) a sealing ring (5) on the socket shank (62) such that the sealing ring (5) rests on the socket base (61); d) placing (S3) the substrate (7) having the socket (60) and the sealing ring (5) in a first mold half (21); e) closing (S4) the first mold half (21) by means of a second mold half (22) in a direction (11) perpendicular to the socket shank (62), thereby elastically deforming the sealing ring (5) by pressing it onto the socket base (61) by means of the second mold half (22) such that the second mold half closes a hollow space (63) of the socket (60), wherein the sealing ring (5) seals the socket shank (62) against the ingress of molding material (10) into the hollow space (63); f) filling (S5) a cavity (23) of the mold (20) with molding material (10); g) opening (S6) the mold (20) after curing the molding material (10); and h) removing the semiconductor power module (1) from the mold (20).

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