Module having an airflow suppression seal at the module interface with the mounting base

Abstract

Disclosed is a module (100), comprising: an electronic component (102); a housing (104) that at least partially surrounds the electronic component (102) and defines a module interface (106), the module (100) being mountable on a mounting base (152) at the module interface (106); and an airflow suppression seal (108), in particular an airtight seal (108), at the module interface (106), which is configured to suppress the propagation of gas from the outside of the module (100) to the electronic component (102).

Description

Technical Field

[0001] The various embodiments generally relate to modules, electronic devices, and methods of manufacturing modules. Background Art

[0002] A power module provides a physical accommodation space for one or more power components (such as power semiconductor devices). These power semiconductor devices can be soldered or sintered onto a substrate, which can in turn be mounted on a support. Considerable effort may be required to ensure the proper reliability of such a module. Summary of the Invention

[0003] There may be a need to manufacture modules with high reliability and that can be used even under harsh conditions.

[0004] According to an exemplary embodiment, there is provided a module including: an electronic component; a housing that at least partially surrounds the electronic component and defines a module interface at which the module is to be mounted on a mounting base; and an airflow suppression (in particular, airflow tight) seal at the module interface, which is configured to suppress the propagation of the atmosphere (including gases) from the outside of the module to the electronic component.

[0005] According to another exemplary embodiment, there is provided an electronic device including: a mounting base; and a module having the above-described features and mounted on the mounting base at its module interface, with a seal between the module and the mounting base.

[0006] According to yet another exemplary embodiment, there is provided a method of manufacturing a module, the method including: at least partially surrounding an electronic component with a housing that defines a module interface at which the module is to be mounted on a mounting base; and providing an airflow suppression (in particular, airflow tight) seal at the module interface for suppressing the propagation of the atmosphere (including gases) from the outside of the module to the electronic component (in particular, by convection) when the module is mounted on the mounting base.

[0007] According to an exemplary embodiment, a module is provided in which corrosion of electronic components (such as power semiconductor chips) can be safely prevented due to the influence of corrosive gases in the module environment during operation. During long-term operation of the module and under harsh conditions (such as the presence of hydrogen sulfide, H2S, and other corrosive gases), the parts of the electronic components encapsulated or surrounded inside the module are corroded by the corrosive medium. This may reduce the reliability and may even completely damage the module. To overcome these problems, the exemplary embodiment sandwiches an airflow-inhibiting seal at the module interface where the module is to be connected to a mounting base (such as a printed circuit board, PCB). After the installation is completed, the nature of the material of the seal combined with the deformability of the seal can ensure a substantially airtight connection between the mounting base and the module. As a result, the electrical reliability and mechanical reliability of the module can be significantly improved. Particularly in the rubber industry and mining applications (where hydrogen sulfide, atmospheric sulfur, carbon disulfide, and other corrosive gases may occur), the module with an airflow-inhibiting seal can be very advantageously used. Descriptively, such corrosive gases may generate dendritic crystals in the corrosive metal pads of the electronic components (such as made of copper and / or silver), which may pose a risk of forming a poor conduction path and thus deteriorating the electrical reliability. By providing an airflow-inhibiting seal between the module and the mounting base, the inflow of the above-mentioned corrosive gases into the interior of the module, and for example, into the soft encapsulation body of the housing encapsulating the electronic components, can be inhibited. In particular, convection can be stopped or greatly reduced by the airflow-inhibiting seal.

[0008] Description of Other Exemplary Embodiments

[0009] Hereinafter, other exemplary embodiments of the module, the electronic device, and the method of manufacturing the module will be described.

[0010] In the context of the present application, the term "module" may particularly denote an electronic component that may include one or more electronic components mounted on one or more carriers. The one or more electronic components may be surrounded by a housing so as to be mechanically protected and / or electrically protected from the environment.

[0011] In the context of the present application, the term "electronic component" may particularly include semiconductor chips (especially power semiconductor chips), active electronic devices (such as transistors), passive electronic devices (such as capacitors, inductors, or ohmic resistors), sensors (such as microphones, optical sensors, or gas sensors), actuators (such as speakers), and microelectromechanical systems (MEMS). In particular, the electronic component may be a semiconductor chip having at least one integrated circuit element (such as a diode or a transistor) in its surface portion. The electronic component may be a bare die or may already be encapsulated or enclosed.

[0012] In the context of the present application, the term "housing" may particularly denote a physical structure or a device formed by a plurality of bodies arranged to surround at least a part of an electronic component. Thus, such a housing may include a casing and / or an encapsulation.

[0013] In the context of the present application, the term "module interface" may particularly denote a connection area configured to be connected to a mounting base such as a printed circuit board.

[0014] In the context of the present application, the term "airflow suppression seal" may particularly denote a physical structure formed by one or more bodies, which may suppress or eliminate airflow or convection by sealing. In particular, convection may be partially or completely stopped by the airflow suppression seal. Gas diffusion through the seal may be eliminated, suppressed, or still occur (especially depending on the diffusion coefficient of the material of the airflow suppression seal, such as a polymer). However, a high filler content in the polymer matrix of the seal may strongly suppress or even minimize diffusion. The material of the seal can thus suppress gas convection or can significantly suppress the airflow through the seal and through the interface between the seal and the surrounding material of the module or electronic device. Preferably, the airflow suppression seal may have sufficient elasticity, deformability, and / or softness such that when a connection is established between the airflow suppression seal at the module interface on one hand and the mounting base on the other hand, gas flow by convection between the inside and the outside of the module is prevented. In particular, corrosive gases may be prohibited from flowing from the outside of the electronic device (formed by the module and the mounting base) into the accommodation volume within the housing in which the electronic components are installed.

[0015] In an embodiment, the housing includes an encapsulation body that at least partially encapsulates the electronic component by physical contact. For example, such an encapsulation body may be a mold-type encapsulation body or a casting compound. In particular, the electronic component may be embedded inside the encapsulation body such that the diffusion of gas (and especially H2S) may be significantly slowed down.

[0016] In an embodiment, the encapsulation body is a soft encapsulation body, especially a silicone gel. The advantage of such a soft encapsulation body is that it protects the electronic components encapsulated in such a soft encapsulation body from excessive mechanical loads, since the soft material of the encapsulation body can balance hard pushes and other mechanical loads. Similarly, the thermal load can be balanced by such a soft encapsulation body. However, in other embodiments, the encapsulation body may be hard (e.g., it may be a molding compound).

[0017] In an embodiment, the housing includes a casing that houses electronic components. Thus, the housing may also include a casing or a cover in which the electronic components can be housed. The casing may further define a receiving volume in which not only the electronic components but also preferably a soft encapsulation body are housed. Descriptively, the casing can serve as a robust external mechanical protection for the enclosed electronic components. For example, the casing may consist of a side wall surrounding the electronic components and an optional top plate.

[0018] In an embodiment, the casing may define or delimit a module interface. In particular, the annular flange surface of the casing may define the module interface. An elastic seal may be arranged to extend along a part of the annular flange surface of the casing or preferably along the entire annular flange surface of the casing. By taking this measure, it can be ensured that the air flow suppression or even the airtight seal of the receiving volume housing the electronic components is effectively achieved.

[0019] In an embodiment, the seal has an annular shape. The annular shape may be a closed-loop or an open-loop shape. For example, the ring may have a circular or rectangular shape. More specifically, the seal may preferably be embodied as a ring structure to circumferentially ensure the airtightness of the connection between the module and the mounting base substantially sufficiently. The annular seal may also provide the following advantage: It will not contact the vertically extending current-carrying pins or needles that may get hot during the operation of the module.

[0020] In an embodiment, the seal is made of a compressible (preferably elastically deformable) material, especially made of foam. When the seal is made of a compressible elastic material such as foam, the seal can be compressed when the module is mounted on the mounting base, thereby closing the minute gaps between the mounting base and the module. Thus, in this compressed state, the seal can fill any small gaps or notches at the module interface, thereby ensuring the required air flow suppression or even airtight property.

[0021] In an embodiment, the seal is made of an elastic material, especially made of one of the Shore 00 material or the Shore A material. When it is an elastic material according to the Shore 00 or Shore A requirements for the ASTM D2240-00 test standard (especially the latest version in effect on the priority date of this application), gas convection may basically not occur through the seal. For example, it is also possible to use other materials for sealing, such as materials at the lower end of the Shore D scale (such as Shore D 35 or Shore D materials below 35). Although these materials may be harder, they may still be suitable for sealing to resist corrosive gases.

[0022] In an embodiment, the sealing portion is made of a gas diffusion inhibiting material. For example, for this purpose, the polymer matrix of the sealing portion may be filled with gas diffusion inhibiting filler particles. Advantageously, the material of the sealing portion may also have low gas diffusivity. This can particularly safely protect the electronic components within the module from unwanted corrosion and the resulting functional degradation.

[0023] In an embodiment, the sealing portion includes sacrificial particles for consuming corrosive gases. The sacrificial particles may be configured to consume corrosive gases, particularly hydrogen sulfide. Thus, these sacrificial particles may be configured to chemically react with corrosive gases, particularly hydrogen sulfide. For example, these sacrificial particles may be configured to be corroded by the corrosive gas, and thus can be consumed. In the context of the present application, the term "gas-consuming sacrificial particles" may particularly refer to particles in the sealing portion that can be corroded by a corrosive gas (such as hydrogen sulfide) reaching the sealing portion. Thus, the corrosive gas can be consumed by the gas-consuming sacrificial particles before the gas reaches the electronic components. Thus, additional protection of the electronic components against unwanted corrosion can be achieved. For example, the gas-consuming sacrificial particles may be made of a base metal (or non-precious metal), preferably a metal less expensive than the material of the pads of the electronic components. For example, the sacrificial particles may be metal powder or metal chips disposed at and / or in the elastomeric material of the sealing portion. The metal powder or metal chips may be made of, for example, copper, iron, silver, etc.

[0024] In an embodiment, the sealing portion includes 3 to 50 volume percent of gas-consuming sacrificial particles (relative to the entire sealing portion material). With such an amount of sacrificial particles, the remaining amount of the (preferably elastomeric) sealing material may be sufficient to provide an appropriate sealing function while reliably consuming the remaining amount of corrosive gas diffusing into the sealing portion material or diffusing through the gap between the module and the mounting base.

[0025] Additionally, alternatively, any surface of the module, and in particular any component of the electronic device, may include gas-consuming sacrificial particles. For example, such gas-consuming sacrificial particles may be applied to at least a portion of the housing, electronic components, etc. This can further improve the corrosion protection of the pads of the electronic components.

[0026] In an embodiment, the electronic component has at least one pad made of a corrodible material, which is particularly a material that can be corroded by a corrosive gas such as hydrogen sulfide. For example, such a corrodible material may be at least one of copper and silver. Even when provided with corrodible pads, due to the airflow-inhibiting sealing portion, the electronic components can be safely protected from unwanted corrosion. Similarly, providing the aforementioned sacrificial particles can improve the corrosion protection of copper or silver pads. Thus, since corrodible pads can also be used, the freedom of the module designer to select materials is further increased.

[0027] In an embodiment, the module includes a carrier, in particular a carrier that is at least partially conductive and / or at least partially thermally conductive, which carries electronic components. In the context of the present application, the term "carrier" can particularly denote a body (preferably, but not necessarily at least partially conductive) that is used to mechanically carry one or more electronic components and can also optionally contribute to the electrical interconnection between the electronic components and the periphery of the module. In other words, the carrier can perform a mechanical carrying function and optionally an electrical connection function. Preferably but not necessarily, the carrier can be partially or fully conductive.

[0028] Such a carrier can have a mechanical support function since it can carry electronic components. However, the carrier may additionally have an electrical function, namely, contribute to the electrical coupling of the electronic components. In one embodiment, the carrier is a lead frame type carrier, i.e., a patterned metal plate. In another embodiment, the carrier includes a central electrically insulating and thermally conductive layer (such as a ceramic sheet), which is covered by corresponding conductive layer structures on its two opposite major surfaces. The conductive layer structures can be continuous and / or patterned copper layers. Thus, the carrier can be, for example, a direct copper bonding (DCB) substrate. In addition to its mechanical support function and optional electrical function, the carrier can also have a function for improving the thermal performance of the module. During the operation of the module, for example when embodied as a power semiconductor chip, the electronic components can generate a large amount of heat. In such a case, the carrier can also be configured to carry the heat out of the module towards, for example, a radiator, which can be connected to the external major surface of the module defined by the carrier. The major surface of the module that can be connected to the radiator can be opposite to another major surface of the module's arrangement seal. The major surface of the carrier that can be connected to the radiator can be opposite to another major surface of the carrier where the electronic components are arranged.

[0029] In an embodiment, the module includes another airflow suppression (preferably, airtight) seal between the carrier and the housing. Thus, the risk of corrosive gas flowing through the interface between the carrier and the housing can be suppressed. All the material properties of the seals described throughout the present application can also be applied to the materials of this another airflow suppression seal.

[0030] In an embodiment, the module includes conductive pins that electrically couple the electronic component to the exterior of the module, particularly to the mounting base. The conductive pins can extend from a carrier on one hand and can extend beyond the housing and even beyond a seal that reaches the exterior of the module. For example, the end of the pin can be inserted into a plated hole of a mounting base configured, for example, as a printed circuit board. It is also possible to establish a solder connection between the mounting base and a pin or a needle outside the mounting base. The opposite end of the pin or needle facing the electronic component can be inserted into a sleeve (or rivet) mounted (e.g., soldered) on the upper main surface of a carrier on which the electronic component is also mounted. The pins can provide an electrical connection between the module on one hand and an electronic environment (e.g., a mounting base) on the other hand. Due to the elastic nature of the seal, the pins can be protected against excessive mechanical loads, particularly excessive mechanical loads at their sleeve side ends when connecting the module and the mounting base.

[0031] In an embodiment, the electronic component is a power semiconductor chip. In particular, when the electronic component is a power semiconductor chip, the reliability against corrosion is particularly advantageous. By providing a seal at the module interface, the air flow inhibition property can be ensured, thereby ensuring corrosion protection of the component pads.

[0032] In an embodiment, the mounting base includes or consists of a printed circuit board (PCB). Such a printed circuit board is a flat body capable of providing both mechanical and electrical connections to the module. Between the printed circuit board and the module, there will be no large amount of corrosive gas passing through.

[0033] In an embodiment, the seal is arranged between the module interface and the mounting base to inhibit the propagation of gas from the exterior of the module to the electronic component. As a result, the electronic component can be at least partially sealed from the air flow within the module and between the mounting base and the module. In addition, through the described configuration, the diffusion of gas to the electronic component can be significantly slowed down.

[0034] In an embodiment, the mounting base and the module are connected by soldering or pressing. Therefore, the formation of the electronic device can be achieved with less effort.

[0035] In an embodiment, the mounting base and the module are connected at the corners of the module. This connection can be achieved by mating the mounting devices (e.g., mounting holes) of the mounting base and the module. For example, such mounting devices can be used to establish a threaded connection between the mounting base and the module.

[0036] In an embodiment, the electronic device includes a heat sink connected to or to be connected to the exposed main surface of the carrier of the module. For example, a mechanical connection (such as a screw connection) can be established between the housing and the heat sink using corresponding mounting means. Connecting the heat sink to the module enables removal of a large amount of heat generated by the electronic components during operation of the electronic device through the carrier and through the heat sink.

[0037] In an embodiment, the module or package includes a plurality of electronic components mounted on a carrier. Thus, the module can include one or more electronic components.

[0038] In an embodiment, the connection between the electronic component and the carrier is formed by a connection medium. For example, the connection medium can be a solder structure, a sintered structure, a fused structure, and / or a glued structure. Thus, one or more electronic components can be mounted on the carrier by soldering, sintering or fusing, or by adhesion or gluing.

[0039] In an embodiment, at least one electronic component includes at least one of the group consisting of a controller circuit, a driver circuit, and a power semiconductor circuit. All of these circuits can be integrated into one semiconductor chip or can be separately integrated in different chips. For example, a corresponding power semiconductor application can be implemented by a chip, wherein the integrated circuit elements of such a power semiconductor chip can include at least one transistor (in particular, a MOSFET, a metal-oxide-semiconductor field-effect transistor, or an IGBT, an insulated-gate bipolar transistor), at least one diode, etc. In particular, circuits implementing a half-bridge function, a full-bridge function, etc. can be manufactured.

[0040] In an embodiment, the module can be configured as a power converter, in particular one of an AC / DC power converter and a DC / DC power converter. However, other electronic applications such as an inverter are also possible.

[0041] In an embodiment, the module includes a clip electrically connected to the upper main surface of the electronic component. Such a clip can be a bent conductive body that achieves an electrical connection to the upper main surface of the corresponding electronic component with a high connection area. By embedding the clip in the module to electrically connect the electronic component to the carrier, any desired conduction path can be established with less effort. In addition to or as an alternative to such a clip, one or more other conductive interconnect bodies, such as bonding wires and / or bonding tapes that connect the electronic component to the carrier or connect different pads of the electronic component, can also be implemented in the module.

[0042] As a substrate or wafer for a semiconductor chip, a semiconductor substrate, i.e., a silicon substrate, can be used. Alternatively, a silicon oxide or another insulator substrate can be provided. A germanium substrate or a III-V semiconductor material can also be implemented. For example, an exemplary embodiment can be implemented in GaN or SiC technology.

[0043] In addition, an exemplary embodiment can utilize standard semiconductor processing techniques, such as appropriate etching techniques (including isotropic and anisotropic etching techniques, especially plasma etching, dry etching, wet etching), patterning techniques (which may include photolithography masks), deposition techniques (such as chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), sputtering, etc.).

[0044] The above and other objects, features, and advantages will become apparent from the following description of the drawings in conjunction with the appended claims, wherein like parts or elements are denoted by like reference numerals. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The drawings are included to provide a further understanding of the exemplary embodiments and constitute a part of the specification, and the drawings illustrate the exemplary embodiments.

[0046] In the figures:

[0047] Figure 1 An electronic device having a mounting base and a module according to an exemplary embodiment is shown.

[0048] Figures 2 to 9 An image of the components of an electronic device and a module according to an exemplary embodiment is shown. DETAILED DESCRIPTION

[0049] The illustrations in the drawings are schematic and not to scale.

[0050] Before describing the exemplary embodiments in more detail with reference to the drawings, some general considerations will be summarized, based on which the exemplary embodiments have been developed.

[0051] According to an exemplary embodiment, a sealing elastomer can be applied between a power module and a mounting base (such as a printed circuit board, PCB) to provide protection against corrosive atmospheric gases.

[0052] The encapsulation material in a power semiconductor module can contain metals that are prone to corrosive degradation and wet metal migration effects. These undesirable phenomena may be caused by exposure to water vapor, sulfur-containing gases such as hydrogen sulfide (H2S), carbonyl sulfide (OCS), gaseous sulfur (S8), and other harmful gases.

[0053] The advantage of the elastomeric seal is that it can establish a reliable connection between the power module and the PCB. When the PCB is mounted on the module, the elastomeric seal can also reduce the pressure applied to the components of the electronic device, such as the pressure applied to the rivets or sleeves that connect the carrier that will carry the electronic components to the pins or pins that provide electrical coupling on the outside of the electronic device. When the electronic components are soldered to the carrier, it is also possible to solder the rivets or sleeves to the carrier (such as a DCB substrate). The elastomeric seal between the housing and the mounting base can prevent the sleeve from bearing excessive loads.

[0054] Although aluminum interconnects and metallizations do not show an obvious tendency to react with those compounds due to their passivating oxide layers, the sulfidation reactions of copper and silver may show high reaction rates. The chemical degradation of these materials can lead to failures of semiconductor chips and the entire module.

[0055] In the process of gradually deploying this metal due to increasing power density, it may be beneficial to address the protection of copper and silver surfaces against corrosive ambient atmospheres through package design.

[0056] Conventionally, many inverters do not have protection against corrosive gases from the environment. Some module design solutions may provide increased robustness against corrosive gases as a side effect: in the case of solid-state encapsulant materials rather than silicone gel-based encapsulants, the flow and / or diffusion of corrosive gases may be reduced. Therefore, these modules may exhibit improved performance in corrosive environments. However, hard encapsulants require a complete redesign and adjustment of the assembly process.

[0057] To adjust the soldering properties or for optical reasons, nickel-plated substrates can be used. This plating also shows lower reactivity to H2S compared to copper, and therefore, it slightly improves the robustness. However, this solution may be inappropriate due to non-compliance with strict test requirements.

[0058] According to an exemplary embodiment, gas robustness can be established at the module level rather than at the component level by providing an airflow suppression (preferably airflow tight, and most preferably airtight) seal between the module and the mounting base used to assemble the module. More specifically, H2S robustness can be made a property of the system (i.e., the entire electronic device), rather than just a property of one component.

[0059] After a sulfur-containing gas (or another corrosive gas) enters the inverter (or another module type), the gas needs to reach the module opening and then reach the reactive metal surface to form sulfide dendrites. Conventional methods may attempt to solve the H2S problem within the power module.

[0060] Advantageously, the exemplary embodiments contribute to improving the gas (and in particular H2S) robustness of the module by sealing the interconnections of the module to the mounting base (e.g., PCB), rather than only by sealing the components or the circuits themselves.

[0061] The power module according to the exemplary embodiments can be soldered or pressed onto the PCB. After this process, the only remaining openings to the external atmosphere are the gaps between the frame and the PCB.

[0062] To overcome the conventional drawbacks, the exemplary embodiments provide a sealing elastomer on top of the module frame, which closes the gap once the module is mounted on the PCB. For example, the sealing elastomer can be applied by a separate washer or O-ring or by a dispensed and cured flexible adhesive (e.g., made of silicone, acrylate, etc.). The benefits of the exemplary embodiments are labor-saving, efficient, and easy to apply.

[0063] Optionally but preferably, the seal or the adhesive can contain sacrificial metal particles. Such a seal or adhesive can be specifically designed to block H2S permeating materials. Such a sacrificial material can also be deposited on top of the semiconductors, substrates, etc. of the module. It can be a reactive, particle-filled insulating layer. The particles can include copper, silver, etc. or can be composed of copper, silver, etc., which are reactive to gaseous sulfur and sulfide compounds. The sulfur-containing gas diffusing towards the module surface can be consumed by the finely dispersed metal-containing particles in the silicone gel matrix. Advantageously, the exemplary embodiments can improve the general H2S robustness of modules such as inverter-type modules.

[0064] A sealing elastomer can be applied between the module and the mounting base (e.g., PCB) to shield the components against corrosive atmospheric gases. For example, this can be implemented in the following ways:

[0065] - An elastomeric seal that is dispensed and thermally cured or photocured (especially UV cured, which saves processing time) made of a soft (e.g., Shore 00 - Shore A) polymer (e.g., silicone, polyurethane, or polyacrylate)

[0066] - An injection-molded seal applied to the frame

[0067] - A sealing washer applied as a separate part, e.g., made of silicone, thermoplastic polyurethane (TPU), ethylene propylene diene monomer rubber (EPDM), polyurethane, etc.

[0068] - A washer-type seal as described above, which is designed to have a foam material to increase compressibility with a lower compression force

[0069] The elastic modulus of the sealant according to an exemplary embodiment can define the allowable compression of the sealant material. According to an exemplary embodiment, a low elastic modulus may be advantageous because it exerts less force on the module contact due to the lower expansion force generated by the sealant under the installation conditions. These forces can then act on the rivet / pin joint or solder joint between the rivet and the substrate. It may be desirable that the forces on these joints are not too large. In addition, a material with high compression and low elastic modulus can allow for better compensation of part tolerances (e.g., between the housing and the PCB).

[0070] The suitable thickness and height of the seal can be, for example, in the range from 1 mm to 3 mm. For better H2S robustness, applying Cu-filled silicone can additionally improve the sealing function. By implementing a screw connection between the module and the PCB at the corners, the forces can be made small enough.

[0071] According to an exemplary embodiment, reducing the air flow path can extend the life of the module in a corrosive atmosphere. In addition, the exemplary embodiment requires only little additional material and process effort to achieve a high level of corrosive gas robustness.

[0072] Figure 1 An electronic device 150 according to an exemplary embodiment is shown having a mounting base 152 and a module 100.

[0073] The illustrated electronic device 150 includes a mounting base 152 embodied as a printed circuit board (PCB). The module 100 is mounted on the mounting base 152 at its module interface 106, and there is a seal 108 therebetween. The air flow inhibiting seal 108 can be a gasket or can be applied by dispensing and then curing. Preferably, the air flow inhibiting seal 108 can establish an airtight connection between the module 100 and the mounting base 152.

[0074] The module 100 includes electronic components 102, such as power semiconductor chips, such as including field effect transistors (FETs). A housing 104 surrounds the electronic components 102 and defines the module interface 106 at which the module 100 will be mounted on the mounting base 152. In addition, the air flow inhibiting seal 108 at the module interface 106 is provided and configured to inhibit the propagation of corrosive gases (such as H2S) from the outside of the electronic device 150 to the electronic components 102 enclosed between the housing 104 and the mounting base 152.

[0075] In the illustrated embodiment, the housing 104 consists of two parts. The first or inner part of the housing 104 is embodied as a soft encapsulation 110 (e.g., made of silicone gel), which directly encapsulates the electronic component 102 by means of physical contact and is applied, for example, by casting or molding. The second or outer part of the housing 104 is embodied as a rigid cover or housing 112, which can be made of plastic and houses the electronic component 102 and the soft encapsulation 110. For example, the housing 112 defines a module interface 106. The housing 112 can have a vertical extension D, which can be, for example, 12 mm. The gap between the housing 112 and the mounting base 152 can have a vertical extension d, which can be, for example, in the range of 1 mm to 2 mm. By closing the gap with the seal 108, the internal resistance of the electronic device 150 to corrosive gases and the environment can be significantly improved.

[0076] Referring again to the hermetic seal 108, it can have an annular shape. When the seal 108 is configured as a ring, any direct physical contact between the sealing material and the hot or current-carrying pins 120 (described in further detail below) can be prevented. Preferably, the seal 108 is made of an elastically compressible material (e.g., foam). The material of the seal 108 can then be elastically compressed by applying pressure, particularly when the module 100 is assembled (e.g., screw-fastened, glued, or welded) to the mounting base 152. Thus, the seal 108 is preferably made of an elastic material. The seal material can be, for example, Shore 00 material or Shore A material. Preferably, the material of the seal 108 is gas-tight, thereby inhibiting the flow of corrosive gases such as H2S through the material of the seal 108. As shown, the seal 108 is arranged between the module interface 106 and the mounting base 152 to inhibit the propagation of gas from the outside of the module 100 to the electronic component 102.

[0077] In a preferred embodiment and as Figure 1As shown in detail at 196, the hermetic airtight elastic seal 108 further includes corrosive gas-consuming sacrificial particles 114, which act as chemisorbent particles. For example, such gas-consuming sacrificial particles 114 can be metal powders embedded in the elastomeric matrix of the seal 108. Advantageously, the gas-consuming sacrificial particles 114 can be made of a corrodible material, and more specifically, can be corroded by corrosive gases such as H2S. Thus, the remaining small amount of corrosive gas diffusing into the seal 108 can be consumed by the gas-consuming sacrificial particles 114, and the gas-consuming sacrificial particles 114 are thereby corroded and thus cannot be used to corrode the pads of the electronic component 102. By taking this measure, the corrosion protection reliability of the interior of the module 100, and in particular the enclosed electronic component 102, can be additionally improved. In other words, the elastic airtight material of the matrix of the seal 108 can cooperate with the gas-corrodible sacrificial particles 114 to improve the corrosion protection of the electronic component 102.

[0078] Although not shown in Figure 1 the gas-corrodible sacrificial particles 114 can also be embedded in the soft encapsulant 110, which can be a silicone gel. The silicone gel can allow some unwanted diffusion of corrosive gases (such as hydrogen sulfide). By providing the encapsulant 110 with gas-corrodible sacrificial particles 114 (such as metal powders), any corrosive gas entering the interior of the module 100 and then entering the encapsulant 110 is consumed by the gas-corrodible sacrificial particles 114 in the encapsulant 110 before reaching the corrodible electrodes or pads 116 of the electronic component 102.

[0079] Taking this fact into account, the electronic component 102 can have one or more pads 116 made of a corrodible material such as copper and / or silver. Since this material is reliably protected against corrosion in the electronic device 150, the design freedom of the module designer in terms of available pad materials can be extended to gas-corrodible pad metals without the risk of corrosion.

[0080] Furthermore, vertically extending conductive pins 120 can be provided, which electrically couple the electronic component 102 and the carrier 118 to the outside of the module 100, more precisely, to the mounting base 152. The pins 120 can also extend through the mounting base 152. More precisely, the bottom end of the pin 120 (according to Figure 1 ) can be connected at the upper main surface of the carrier 118. For example, a rivet or a sleeve ( Figure 1 not shown in) can be connected, for example, by welding, at the upper main surface of the carrier 118. In addition, the top end of the pin 120 (according to Figure 1) can be guided through the mounting base 152 and can even protrude beyond the upper side of the mounting base 152. A connection, such as a solder connection, can also be established on the outer side of the mounting base 152 between the mounting base 152 and the upper end of the needle 120.

[0081] Similarly, as Figure 1 shown, the module 100 includes a carrier 118 that bears electronic components 102. The electronic components 102 can be soldered onto the carrier 118. In the illustrated embodiment, the carrier 118 includes a central thermally conductive and electrically insulating plate 197 (e.g., made of ceramic), which is covered with corresponding conductive layers 198, 199 (e.g., continuous or patterned copper or aluminum layers) on its two opposite main surfaces. For example, the carrier 118 can be a direct copper bonding (DCB) substrate or a direct aluminum bonding (DAB) substrate. The carrier 118 can also be embodied as an active metal brazing (AMB) substrate. The component 102 is mounted on the top-side conductive layer 198. The bottom-side conductive layer 199 can be connected to a heat sink (not shown) to facilitate heat removal from the module 100 during operation of the module 100.

[0082] Thus, the outer layer 199 of the carrier 118 is configured to have a heat sink (not shown) mounted thereon so as to effectively remove heat generated by the electronic components 102 mounted on the inner layer 198 of the carrier 118 from the module 100. The electronic components 102 can be, for example, power semiconductor chips. The electrical connection of the electronic components 102 can be achieved through the carrier 118 (especially through its internal conductive layer 198) and through conductive connection elements 170 that connect the carrier 118 to pads 116 on the upper main surface of the electronic components 102. The conductive connection elements 170 are implemented here as bonding wires, but can alternatively be bonding tapes or clips.

[0083] Similarly, as shown, the electronic components 102 mounted on the carrier 118 are enclosed within a housing 104, which consists of the walls of a soft encapsulation 110 and a housing 112.

[0084] The module 100 also includes another airflow suppression seal 109 between the carrier 118 and the housing 112 of the housing 104. This another airflow suppression seal 109 can be an absorbent bead of glue. This another airflow suppression seal 109 can be made of the same material as the airflow suppression seal 108. The risk of corrosive gas flowing through the interface between the carrier 118 and the housing 104 can be suppressed by the another seal 109. For example, the another airflow suppression seal 109 can be a silicone glue, which further improves the robustness against corrosive gases.

[0085] The conductive pins 120 extend from the carrier 118 through the encapsulation 110 and through the seal 108 at the module interface 106 where the module 100 faces the mounting base 152. For example, the module 100 and the mounting base 152 can be connected by screw fastening, welding, sintering, gluing, and / or mechanical pressing. During such connection, the seal 108 ensures that no corrosive gas can propagate upward from the outside of the illustrated electronic device 150 to the electronic components 102. The electronic components 102 can thus be provided with corrosive pads 116 made of, for example, copper and aluminum. However, since corrosive gases can be safely prevented from reaching the electronic components 102, no corrosion problems occur. The mounting holes 180 in the PCB-type mounting base 152 ensure a mechanical and electrical connection of the pins 120 to the mounting base 152. In particular, the mounting holes 180 can be plated to establish such an electrical connection. The pins 120 can be guided through the mounting holes 180 with substantially no gap therebetween. If a very small gap is left, the amount of corrosive gas flowing through or diffusing through such a small gap may be small enough, and in particular, convection caused by air flow can be strongly suppressed or even completely eliminated.

[0086] As can be seen from Figure 1 the detail 196 shown, the seal 108 can be made of an elastomeric material that is substantially gas-proof in itself or can only permit a very small degree of air flow. Corrosive particles 114 can be embedded in the seal 108. The corrosive particles 114 can be made of, for example, iron, copper, or another base metal, so that any corrosive gas in the electronic environment of the illustrated electronic device 150 will corrode the sacrificial particles 114 of the seal 108 rather than the pads 116 of the electronic components 102.

[0087] Due to the described construction, the electronic components 102 are at least partially sealed from air flow within the module 100 and between the mounting base 152 and the module 100, particularly against the ingress of corrosive gases such as hydrogen sulfide.

[0088] Figures 2 to 9 An image of the components of the electronic device 150 and the module 100 according to an exemplary embodiment is shown.

[0089] Reference Figure 2, the mounting base 152 is shown from the side facing away from the module 100, which is embodied here as a printed circuit board. As shown, the mounting base 152 has a first mounting hole 180 through which the conductive pins 120 can be guided. The first mounting hole 180 can be plated to establish an electrical connection with the pins 120. Thus, the first mounting hole 180 can be a plated through-hole. In addition, second mounting holes 182 are provided in the corners of the mounting base 152 for establishing a mechanical connection with the module 100, which has corresponding mounting holes 184 at the corners, see Figure 3 and Figure 4 . Preferably, the mounting base 152 and the module 100 are connected at the corners of the module 100. This can improve reliability and does not interfere with the function of the seal 108.

[0090] Referring again to Figure 2 , third mounting holes 186 are provided along the opposite side edges of the mounting base 152 for establishing a connection with the mechanical connection element 188 of the module 100 shown in Figure 3 . For example, the mechanical connection element 188 can be a metal spring. The mechanical connection element 188 can be used to establish a mechanical connection (e.g., a screw connection) with a heat sink (not shown) to be attached to the exposed lower main surface of the carrier 118. Such a heat sink can remove the heat generated by the electronic components 102 during the operation of the electronic device 150. The heat can be conducted upward through the thermally conductive carrier 118 to the heat sink to cool the module 100.

[0091] For assembling Figure 3 the electronic device 150, the module 100 can be connected to the mounting base 152. Subsequently, the obtained device can be connected to the heat sink using the connection element 188 for attachment.

[0092] Figure 4 shows the module 100 without the mounting base 152 Figure 2 and Figure 3 .

[0093] In Figure 5 , Figure 6 and Figure 7 , different views of the module 100 without the mounting base 152 are shown. It can be seen that the seal 108 is embodied here as four straight strips of elastic material arranged in a substantially annular manner, with short interruptions only in the corner regions corresponding to the mounting holes 184. For example, the material of the seal 108 can be distributed in the shown shape. Alternatively, the seal 108 can be provided as a separate workpiece to be attached to the flange surface of the housing 112, such as a separate washer. Figures 4 to 7Also shown is the top plate 190 of the cover 112 of the housing 104. The top plate 190 is provided with a fourth mounting hole 192 which cooperates with the first mounting hole 184 of the mounting base 152 for guiding the conductive pin 120 therethrough. In addition, one or more filling ports 131 may be provided in the top plate 190 as through holes for filling the material for manufacturing the soft encapsulation body 110.

[0094] Reference Figure 8 and Figure 9 , another embodiment of the module 100 is shown, in which the top plate 190 is additionally provided with parallel slits 194.

[0095] It should be noted that the term "comprising" does not exclude other elements or features, and "a" does not exclude a plurality. Moreover, elements described in connection with different embodiments may be combined. It should also be noted that the reference numerals should not be construed as limiting the scope of the claims. Moreover, the scope of the present application is not intended to be limited to the specific embodiments of the processes, machines, manufactures, compositions of matter, means, methods, and steps described in the specification. Therefore, the appended claims are intended to include such processes, machines, manufactures, compositions of matter, means, methods, or steps within their scope.

Claims

1. An electronic device (150), wherein, The electronic device (150) includes: A printed circuit board (152), wherein the printed circuit board (152) includes mounting holes (180); and A module (100), wherein the module (100) includes: Electronic components (102); Conductive pins (120) that electrically couple the electronic components (102) to the printed circuit board (152); A housing (104) including a housing body (112) that at least partially surrounds the electronic components (102) and the conductive pins (120), the housing body (112) defining a module interface (106) at which the module (100) is to be mounted on the printed circuit board (152); and A sealing portion (108) between the module interface (106) and the printed circuit board (152), the sealing portion (108) being configured to inhibit gas from propagating from the outside of the module (100) to the electronic components (102), wherein the conductive pins (120) extend through the sealing portion (108) and the mounting holes (180).

2. The electronic device (150) according to claim 1, wherein, The housing (104) further includes an encapsulant (110) that at least partially encapsulates the electronic components (102) by physical contact, and the housing body (112) houses the electronic components (102) and the encapsulant (110).

3. The electronic device (150) according to any one of claims 1 and 2, wherein, The sealing portion (108) has an annular shape.

4. The electronic device (150) according to claim 3, wherein, The annular shape includes the shape of a closed ring or an open ring.

5. The electronic device (150) according to any one of claims 1, 2 and 4, wherein, The sealing portion (108) is made of a compressible material.

6. The electronic device (150) according to claim 5, wherein, The compressible material includes foam.

7. The electronic device (150) according to any one of claims 1, 2 and 4, wherein, The sealing portion (108) is made of an elastic material.

8. The electronic device (150) according to claim 7, wherein, The elastic material includes one of Shore 00 material, Shore A material, and Shore D material below 35.

9. The electronic device (150) according to any one of claims 1, 2, 4, 6 and 8, wherein, The module (100) further includes a carrier (118) that carries the electronic components (102).

10. The electronic device (150) according to claim 9, wherein, The carrier (118) includes a carrier (118) that is at least partially conductive and / or at least partially thermally conductive.

11. The electronic device (150) according to claim 10, wherein, The electronic components (102) are at least partially sealed from air flow between the housing body (112), the carrier (118), and the printed circuit board (152).

12. The electronic device (150) according to any one of claims 1, 2, 4, 6, 8, 10 and 11, wherein, The module (100) further includes another air flow inhibiting sealing portion (109) between the carrier (118) and the housing body (112).

13. The electronic device (150) according to any one of claims 1, 2, 4, 6, 8, 10 and 11, wherein, The module (100) includes at least one of the following features: Wherein the sealing portion (108) includes or consists of a gas diffusion inhibiting material; Wherein the sealing portion (108) includes sacrificial particles (114) configured to consume corrosive gases; Wherein the electronic components (102) have at least one pad (116) made of a corrodible material; Wherein the electronic components (102) are power semiconductor chips.

14. The electronic device (150) according to claim 13, wherein, The corrosive gas includes hydrogen sulfide, and the corrodible material includes a material that can be corroded by the corrosive gas.

15. The electronic device (150) according to any one of claims 1, 2, 4, 6, 8, 10, 11, and 14, wherein, The printed circuit board (152) and the module (100) are connected at a corner of the module (100).

16. The electronic device (150) according to claim 15, wherein, The printed circuit board (152) and the module (100) are connected only at a corner of the module (100).

17. A method of manufacturing the electronic device (150) according to any one of the preceding claims, wherein, The method includes: At least partially enclosing the electronic component (102) in the housing (112), the housing (112) defining the module interface (106), the module (100) being configured to be mounted on the printed circuit board (152) at the module interface (106); Providing the conductive pins (120) and electrically coupling the electronic component (102) to the printed circuit board (152) via the conductive pins (120); Providing the seal (108) at the module interface (106) for inhibiting gas from propagating from the exterior of the module (100) toward the electronic component (102); and Mounting the module (100) at the printed circuit board (152) such that the conductive pins (120) extend through the seal (108) and the mounting holes (180).

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