Housing with encapsulating material and further encapsulating material thereon, as well as manufacturing process for this housing

Abstract

Housing (100) which has the following features: • a carrier (102); • an electronic component (108) mounted on the carrier (102); • an encapsulating agent (110), ◯ wherein the encapsulating means (110) at least partially encapsulates the electronic component (108) and the carrier (102); ◯ wherein electrically conductive particles (104) are embedded in the encapsulating agent (110); and ◯ wherein the encapsulating agent (110) contains no more than 0.1 percent by weight, in relation to the total weight of the encapsulating agent (110), of electrically conductive particles (104), • a further encapsulation means (112) covering an outer surface of at least part of the encapsulation means (110) and comprising a greater quantity of electrically conductive material (106) than the encapsulation means (110).

Description

Background Technical field

[0001] Various embodiments generally relate to a housing and a method for manufacturing a housing. Description of the state of the art

[0002] A conventional housing may contain an electronic component mounted on a chip carrier, such as a conductor frame, may be electrically connected, for example, by a bond wire extending from the chip to the chip carrier or to a lead wire, and may be potted using a potting compound as an encapsulating agent.

[0003] DE 10 2015 108 246 A1 discloses a housing with an electronic chip mounted on a carrier, wherein an insulating layer is formed over the electronic chip and the carrier. The carrier, the electronic chip, and the insulating layer above it are all embedded in an encapsulation comprising an electrically conductive filler material.

[0004] WO 2017 / 052 243 A1 discloses a housing for encapsulating a semiconductor component, wherein the housing contains industrial carbon black for laser marking purposes.

[0005] JP 2001- 2 895 A discloses a semiconductor package with a potting compound as an encapsulation body, which includes, among other things, industrial carbon black as a filler material.

[0006] KR 10 2017 0 127 816 A discloses a housing for a semiconductor device for shielding against electromagnetic radiation.

[0007] KR 10 2017 0 109 479 A discloses a housing of a semiconductor device with a first encapsulation means and a second encapsulation means formed above it for shielding against electromagnetic radiation.

[0008] The electrical reliability of a conventional enclosure can be a problem. Brief description

[0009] There may be a need for an enclosure with high electrical reliability.

[0010] According to one embodiment, a housing is provided comprising: a support, an electronic component mounted on the support, an encapsulating means wherein the encapsulating means at least partially encapsulates the electronic component and the support, wherein electrically conductive particles are embedded in the encapsulating means and wherein the encapsulating means comprises not more than 0.1 percent by weight, with respect to a total weight of the encapsulating means, of electrically conductive particles, and a further encapsulating means which covers an outer surface of at least a part of the encapsulating means and comprises a greater quantity of electrically conductive material than the encapsulating means.

[0011] According to a further embodiment, a method for manufacturing a housing is provided, the method comprising: mounting an electronic component on a carrier, at least partially encapsulating the electronic component and the carrier by an encapsulating means, wherein electrically conductive particles are embedded in the encapsulating means; wherein the encapsulating means has no more than 0.1 percent by weight, with respect to a total weight of the encapsulating means, of electrically conductive particles, and forming a further encapsulating means on an outer surface of at least a part of the encapsulating means, wherein the further encapsulating means has a greater quantity of electrically conductive material than the encapsulating means.

[0012] According to one embodiment, a housing comprises a carrier on which an electronic component is mounted. A first encapsulating means containing no more than 0.1% by weight of electrically conductive particles (or, more generally, an electrically conductive material) can encapsulate the electronic component and the carrier. Furthermore, a second encapsulating means can at least partially cover the first encapsulating means and comprise a larger quantity of electrically conductive material (or, in particular, electrically conductive particles). Advantageously, such a housing design can lead to high electrical reliability. The inner, first encapsulating means, which can be free of electrically conductive particles (such as carbon black), can lead to improved breakdown voltage and improved long-term high-voltage stability.Simultaneously, a small amount of, or even the absence of, electrically conductive particles in the inner, first encapsulating material can advantageously reduce the tendency to corrosion and improve the adhesion of the components in contact with the first encapsulating material. Furthermore, it is advantageous to surround the first, inner encapsulating material, at least partially, with a second, outer encapsulating material containing a larger amount of electrically conductive particles (for example, carbon black) to provide the housing with improved electrostatic discharge (ESD) protection without impairing the beneficial effects of the inner, first encapsulating material with regard to electrical reliability.In short, the electrically conductive material (especially electrically conductive particles) of the second encapsulating medium can contribute to the removal of charge carriers from the housing, thus protecting the housing from unwanted electrical charging. Furthermore, providing the outer encapsulating medium with electrically conductive particles (such as carbon black) can make the outer surface of the housing suitable for laser marking, which can be facilitated by carbon black or the like. In a preferred embodiment, a core encapsulating medium can be provided with fewer electrically conductive particles than a surrounding shell encapsulating medium. This can make it possible to obtain a housing with the aforementioned advantages in combination. Description of further examples of implementation

[0013] Further examples of the housing and the method are explained below.

[0014] In the context of the present application, the term "housing" can, in particular, refer to an electronic device which may comprise one or more electronic components mounted on a (particularly partially or fully electrically conductive) support. The components of the housing may be at least partially encapsulated by an encapsulating means. Optionally, one or more electrically conductive connecting elements (such as metallic pillars, contact bumps, bond wires and / or clamps) may be implemented in a housing, for example for electrical coupling and / or mechanical support of the electronic component.

[0015] In the context of the present application, the term "support" can, in particular, denote a support structure (which may be at least partially electrically conductive) that serves as a mechanical support for the electrical component(s) to be mounted on it and that may also contribute to the electrical connection between the electronic component(s) and the periphery of the enclosure. In other words, the support can fulfill a mechanical support function and, optionally, an electrical connection function. A support can be a single piece, several pieces joined together via encapsulation or other enclosure components, or a subassembly of supports. If the support forms part of a conductor frame, it can be or include a die pad.For example, such a substrate can be a conductor frame structure (e.g., made of copper), a DAB (Direct Aluminum Bonding) substrate, a DCB (Direct Copper Bonding) substrate, etc. Furthermore, the substrate can also be configured as an active metal brazing (AMB) substrate. In addition, at least part of the substrate can be encapsulated by the encapsulating material, along with the electronic component.

[0016] In the context of the present application, the term "electronic component" can include, in particular, a semiconductor chip (especially a power semiconductor chip), an active electronic device (such as a transistor), a passive electronic device (such as a capacitor, an inductor, or a resistor), a sensor (such as a microphone, a light sensor, or a gas sensor), an actuator (for example, a loudspeaker), and a microelectromechanical system (MEMS). However, in other embodiments, the electronic component may also be of a different type, such as a mechatronic element, in particular a mechanical switch, etc. In particular, the electronic component may be a semiconductor chip with at least one integrated circuit element (such as a diode or a transistor) in a surface portion thereof.The electronic component can be a bare chip or it can already be encapsulated or encapsulated. Semiconductor chips implemented according to the exemplary embodiments can be implemented using silicon technology, gallium nitride technology, silicon carbide technology, etc.

[0017] In the context of the present application, the term "encapsulating means" can, in particular, refer to a material, structure, or element that surrounds at least part of an electronic component and at least part of a support to provide mechanical protection and, optionally, electrical insulation and / or contribute to heat dissipation during operation. In particular, the encapsulating means can be mainly or even entirely electrically insulating, for example, a potting compound. A potting compound can comprise a matrix of flowable and curable material and embedded filler particles. For example, filler particles can be used to tailor the properties of the potting component, in particular to improve its thermal conductivity.As an alternative to a potting compound (for example, based on epoxy resin), the encapsulating agent can also be a potting compound (for example, based on a silicone gel).

[0018] In the context of the present application, the term "further encapsulation means" can, in particular, denote a material, structure, or element that at least partially covers or surrounds the aforementioned first or inner encapsulation means. Therefore, the further encapsulation means can be an outer encapsulation means. For example, the further encapsulation means can be a further potting compound or an electronic element (such as a further support, for instance, a ceramic plate covered on both opposing main surfaces by a metallic layer) in order to serve as an encapsulation entity with respect to the first or inner encapsulation means.

[0019] In the context of this application, the term "electrically conductive particles" may, in particular, refer to particles that are distributed within a matrix material (for example, a dielectric potting compound) of the assigned encapsulating agent and that exhibit electrical conductivity. The electrically conductive particles may be connected with respect to other electrically conductive particles or may be unconnected with respect to them. An electrical conductivity may correspond to an electrical conductivity (at 20 °C) of at least 0.01 S / cm, in particular at least 0.05 S / cm, preferably at least 0.1 S / cm, for example at least 1 S / cm. In particular, the electrically conductive particles may comprise carbon, in particular carbon black, and / or a metallic material. For example, the electrically conductive particles may be shaped as beads, spheres, cuboids, and / or plates, etc.

[0020] In the context of the present application, the term ‘electrically conductive material’ may in particular refer to electrically conductive particles, as described above, or to a continuous or structured electrically conductive structure, such as a metallic layer.

[0021] In the context of the present application, the term "industrial carbon black" can, in particular, refer to a fine carbon powder produced by burning hydrocarbons in insufficient air. Specifically, industrial carbon black can refer to a material produced by the incomplete combustion of coal and coal tar, vegetable material, or petroleum products, including fuel oil, tar from catalytic fluid cracking, and ethylene cracking, in a limited supply of air. Industrial carbon black can be a black, finely divided form of amorphous carbon.

[0022] In one embodiment, the encapsulating material contains electrically conductive particles, for example, carbon black, in a range of 0.025% to 0.05% by weight of the total weight of the encapsulating material. At this small quantity, electrically conductive particles, such as carbon black, can still contribute to ESD protection and / or laser marking capability, while demonstrating adequate electrical breakdown voltage and time-dependent dielectric breakdown (TDDB) behavior.

[0023] In another embodiment, the encapsulating material contains no electrically conductive particles. A person skilled in the art will understand that an encapsulating material containing no electrically conductive particles may still contain an unavoidable residue of electrically conductive particles due to manufacturing tolerances and the like. Since it contains essentially no electrically conductive particles, the encapsulating material can exhibit excellent electrical breakdown voltage and advantageous TDDB behavior.

[0024] In one embodiment, the encapsulating material contains no more than 0.05 percent by weight, relative to the total weight of the encapsulating material, of carbon black as electrically conductive particles. Such a small amount of carbon black may be acceptable with regard to electrical reliability and may even contribute to ESD protection and / or laser marking capability.

[0025] In one embodiment, the electrically conductive material of the further encapsulation medium comprises electrically conductive particles, such as industrial carbon black (see, for example, [reference]). Fig. 1) or has at least a metal layer (compare for example Fig. 3) Such an electrically conductive material in the form of particles or one or more layers or layered structures can improve the electrostatic discharge properties of the housing as a whole.

[0026] In one embodiment, the encapsulating agent comprises a potting compound. For example, such a potting compound may comprise an epoxy resin, filler particles, optionally additives, and optionally a limited amount of electrically conductive particles, such as carbon black.

[0027] In one embodiment, the further encapsulation means comprises a potting compound which in particular includes industrial carbon black as the electrically conductive material (see, for example, Fig. 1) For example, such an additional potting compound may contain another epoxy resin, additional filler particles, optionally further additives, and a certain amount of electrically conductive particles, such as carbon black. For example, the additional encapsulating agent may be formed by overmolding the previously mentioned encapsulating agent.

[0028] In another embodiment, the additional encapsulation means is a further carrier (see, for example, Fig.3) In particular, the further encapsulating means may comprise a ceramic plate (which may be thermally conductive and electrically insulating, for example, aluminum oxide or aluminum nitride) covered on both opposing main surfaces with a metal layer (for example, copper or aluminum layers) as the electrically conductive material. If such a further support is arranged on an outer surface of the aforementioned encapsulating means, it may function as a further encapsulating means.

[0029] In one embodiment, each of the carriers and the further carrier beyond the encapsulation means is exposed for heat dissipation generated by the electronic component by means of double-sided cooling. Therefore, heat generated by the electronic component (for example, a power semiconductor chip) can be dissipated from the housing via both exposed carriers through two opposite sides and thus with high efficiency. For this reason, the at least one electronic component can preferably be thermally coupled to both carriers. For example, the electronic component can be mounted on one carrier and can be thermally connected to the other carrier by means of a thermally conductive spacer between them.

[0030] In one embodiment, the encapsulating means forms an inner core, and the other encapsulating means forms an outer shell on at least a part of the inner core. With such a core-shell configuration of the system with two encapsulating means (where more than two encapsulating means may also be provided), the technical functions of the inner encapsulating means and the outer encapsulating means can be combined in a structurally advantageous way.

[0031] In one embodiment, the outer encapsulating means is configured to provide better protection against electrostatic discharge (ESD) than the inner encapsulating means. In particular, ESD protection can be provided mainly or entirely by the outer encapsulating means, which may contain a larger quantity of electrically conductive particles than the inner encapsulating means.

[0032] In one embodiment, the additional encapsulating material is configured as the encapsulating material to enable improved laser marking on and / or within it. Laser marking of a housing can be significantly enhanced by industrial carbon black, which can be characteristically modified by laser treatment in a surface area of ​​the additional encapsulating material.

[0033] In one embodiment, the encapsulating material is in direct physical contact with the electronic component and / or the substrate, while the secondary encapsulating material is not. Removing carbon black from the encapsulating material that is in direct contact, particularly with the electronic component, provides adequate protection against corrosion for the electronic component. At the same time, a large or greater quantity of carbon black in the secondary encapsulating material does not impair the corrosion protection of the electronic component, since the latter is not in direct physical contact with the secondary encapsulating material. Similar considerations apply to the other advantages of larger and smaller quantities of electrically conductive particles, such as carbon black particles, as previously mentioned.

[0034] In one embodiment, the additional encapsulating element defines part of the outer outline of the housing. Therefore, the additional encapsulating element can be located remotely from the electronic component, which can further improve electrical reliability. Simultaneously, the additional encapsulating element, which extends to the outer surface of the housing, can be used for laser marking and ESD protection.

[0035] In one embodiment, the encapsulating material is configured to provide higher safety with respect to time-dependent dielectric breakdown (TDDB) than the other encapsulating material. Surprisingly, this improvement in electrical reliability can be achieved by reducing the amount of carbon black in the encapsulating material (see Fig. 7 and Fig. 8).

[0036] In one embodiment, the encapsulating medium is configured to provide higher high-voltage safety than the other encapsulating medium. Surprisingly, this improvement in electrical reliability can be achieved by reducing the amount of carbon black in the encapsulating medium (see Fig. 6).

[0037] In one embodiment, the electrically conductive particles comprise carbon black, titanium oxide, and / or crystalline petroleum coke. These particles provide a degree of electrical conductivity for removing charge carriers from the housing. However, the electrical conductivity of these materials is not excessively high. The risk of unwanted current conduction along parasitic paths can therefore be reduced. Consequently, these materials are very well suited as electrically conductive particles in one or both of the encapsulating materials.

[0038] In one embodiment, the electrically conductive particles have an electrical conductivity of at least 0.01 S / cm, specifically at least 0.1 S / cm, particularly in a range of 0.05 S / cm to 500 S / cm, for example in a range of 0.1 S / cm to 100 S / cm. The electrical conductivity of the electrically conductive particles can be lower than the metallic conductivity (for example, of materials such as copper or aluminum), which may be preferred for the function of the electrically conductive particles in the housing.

[0039] In one embodiment, the encapsulating agent does not contain a low-mechanical-stress additive (such as rubber or silicone particles). As in Fig. As shown and described in Figure 6, the omission of low mechanical stress additives can surprisingly lead to advantageous dielectric strength behavior.

[0040] In one embodiment, the encapsulating agent comprises uncoated filler particles. Again with reference to Fig. 6. The implementation of filler particles (for example, to improve thermal conductivity) in the encapsulating material, which do not have a coating (but are preferably made of a homogeneous material), can lead to an improvement in dielectric strength behavior.

[0041] In one embodiment, part of the support is exposed beyond the encapsulation means and beyond the further encapsulation means. This can improve the heat dissipation capacity of the housing via the support, which can carry the main heat source of the housing, i.e., the electronic component.

[0042] In one embodiment, the encapsulating agent comprises an electrostatic dissipative material. For example, the electrostatic dissipative material may include electrically conductive particles bonded to segments of an epoxy backbone of the encapsulating agent material. Additionally or alternatively, the electrostatic dissipative material may include short electrically conductive chemical groups that have reacted with epoxy material of the encapsulating agent.

[0043] In one embodiment, the method involves forming the additional encapsulation material by casting, in particular overmolding, onto at least a portion of the encapsulation material. The formation of two different casting-type encapsulation materials with the previously described properties enables a simple manufacturing process and high electrical reliability of the resulting housing.

[0044] In another embodiment, the method involves forming the further encapsulating material by coating at least a portion of the encapsulating material. For example, such a coating process can be achieved by brushing, spraying, depositing, and / or dipping. Furthermore, such a manufacturing process is simple and allows for the individual customization of the properties of the encapsulating material and the further encapsulating material with a high degree of design freedom.

[0045] In yet another embodiment, the method involves forming the additional encapsulating agent by modifying a surface portion of the encapsulating agent. Accordingly, the additional encapsulating agent can be produced as a prior outer portion of the other encapsulating agent, which can be modified (for example, chemically) to adjust, in particular, the concentration of electrically conductive particles, preferably carbon black, within it.

[0046] In one embodiment, the modification of the surface portion of the encapsulating material is carried out by at least one of the following: ultraviolet-induced carbonization, laser treatment, electron beam treatment, phase separation based on hydrophobicity, flame treatment, burning, and oxidation. For example, the outer surface of the encapsulating material can be irradiated with ultraviolet radiation, which can carbonize material from the previous encapsulating material. As a result, electrically conductive particles, such as carbon black, can be selectively formed in a surface portion of the previous encapsulating material, which then becomes the subsequent encapsulating material.

[0047] In one embodiment, the housing comprises at least one further electronic component mounted on the carrier and / or another carrier. In particular, a plurality of electronic components can be mounted side by side and / or on top of each other on the same carrier and / or on different carriers of the same housing. The electronic components can be interconnected or can operate independently of each other.

[0048] In one embodiment, the package is configured as a power package. A power package can be a package that includes at least one power chip as an encapsulated electronic component. Accordingly, the package can be configured as a power module, for example, an encapsulated power module such as a semiconductor power module. For example, one embodiment of the package can be an intelligent power module (IPM). Another embodiment of the package is a dual inline package (DIP).

[0049] Accordingly, the electronic component can be configured as a power semiconductor chip. Therefore, the electronic component (such as a semiconductor chip) can be used for power applications, for example in the automotive sector, and can, for instance, include at least one integrated insulated-gate bipolar transistor (IGBT) and / or at least one transistor of another type (such as a MOSFET, a JFET, a HEMT, etc.) and / or at least one integrated diode. Such integrated circuit elements can be manufactured, for example, using silicon technology or based on wide-bandgap semiconductors (such as silicon carbide, gallium nitride). A semiconductor power chip can include one or more field-effect transistors, diodes, inverter circuits, half-bridges, full-bridges, drivers, logic circuits, other devices, etc.The advantages of exemplary embodiments with regard to electrical insulation and thermal dissipation are particularly pronounced for power dies.

[0050] In one embodiment, the carrier features a die pad of the conductor frame type. A conductor frame can be a metal structure within the housing that carries signals from the electronic component outwards and / or in the opposite direction. The conductor frame can have a central die pad on which the electrical component is placed, surrounded by leads, i.e., metal conductors, that lead from the electronic component away from the housing's electronic power supply and / or in the opposite direction.

[0051] In one embodiment, the housing includes a heat sink mounted on a portion of the encapsulating material facing the support or on another encapsulating material of the support type. Such a heat sink can be a thermal dissipation body made of a highly thermally conductive material, such as copper or aluminum, and can be attached to the encapsulating material surface closest to the rear of the support. For example, such a heat sink can have a base body directly connected to the surface of the housing and can have a plurality of cooling fins extending from the base body and parallel to each other, so that heat is dissipated to the environment.

[0052] In one embodiment, the housing features an electrically conductive connecting element that electrically couples the electronic component to the substrate and / or to at least one lead. Such an electrically conductive connecting element can be a clamp, a bond wire, or a bond tape. A clamp can be a curved, electrically conductive body that provides an electrical connection with a high contact area up to a top main surface of the respective electronic component. In addition to or as an alternative to such a clamp, it is also possible to implement one or more other electrically conductive connecting elements in the housing, for example, a bond wire and / or a bond tape that connects the electrical component to the substrate and / or a lead, or connects different pads of an electronic component.

[0053] In one embodiment, the package is configured as one of the group consisting of a power module with an attached conductor frame, a Control Integrated Power System (CIPOS) package, a Transistor Outline (TO) package, a Quad Flat No Leads Package (QFN) package, a Small Outline (SO) package, a Small Outline Transistor (SOT) package, and a Thin Small Outline Package (TSOP) package. Packages for sensors and / or mechatronic devices are also possible embodiments. Furthermore, embodiments may also include packages that function as nanobatteries or nanofuel cells, or other devices with chemical, mechanical, optical, and / or magnetic actuators. Therefore, according to one embodiment, the package is fully compatible with standard encapsulation concepts and appears externally as a conventional package, which is very user-friendly.

[0054] A semiconductor substrate, particularly a silicon substrate, can be used as the substrate or wafer that forms the basis of the electronic components. Alternatively, a silicon oxide or other insulator substrate can be provided. It is also possible to implement a germanium substrate or a III-V semiconductor material. For example, embodiments can be implemented using GaN or SiC technology.

[0055] The above and other objectives, features and advantages will become apparent from the following description and the attached claims in conjunction with the accompanying drawings, in which identical parts or elements are designated by the same reference numerals. Brief description of the drawings

[0056] The accompanying drawings, which are included to provide a better understanding of exemplary implementations and which form part of the text, illustrate exemplary implementations.

[0057] The following applies to the drawings: Fig. Figure 1 illustrates a cross-sectional view of a housing according to an exemplary embodiment. Fig. Figure 2 illustrates a flowchart of a process for manufacturing a housing according to an exemplary embodiment. Fig. Figure 3 illustrates a cross-sectional view of a housing according to another embodiment. Fig. Figure 4 illustrates a three-dimensional view of a preform of a housing according to another embodiment. Fig. Figure 5 illustrates a component of a housing according to another embodiment. Fig. 6 to Fig.8. Diagrams illustrate the effects of exemplary implementations compared to conventional approaches. Fig. Figure 9 illustrates structures obtained during the manufacture of a housing according to an exemplary embodiment. Fig. Figure 10 illustrates structures obtained during the manufacture of a housing according to another embodiment. Detailed description

[0058] The illustration in the drawing is schematic and not to scale.

[0059] Before exemplary embodiments are described in more detail with reference to the figures, some general considerations on which exemplary embodiments were developed are summarized.

[0060] Epoxy potting compounds are commonly used for encapsulating semiconductor components. These polymer composites are used to provide mechanical stability to the housing (for example, to hold leads) as well as to protect the semiconductor component from environmental influences. Various additives are used to meet different requirements for the encapsulation material. One of the additives typically used is a colorant, which may be electrically conductive. These colorants (typically carbon black) are used to ensure that the potting compound has a stable, uniform color (for example, black in the case of carbon black). Carbon black is also used as an ESD (electrostatic discharge) protection agent to reduce the risk of ESD to the housing, given its intrinsic electrical conductivity.

[0061] However, in recent studies, inventors have discovered that an excessive amount of carbon black is detrimental when it comes to partial discharge measurements and measurements of time-dependent dielectric breakdown. Here, an excessive amount of carbon black can cause a reduced breakdown voltage (BDV) in consecutive BDV measurements. Without being limited to a specific theory, it is currently assumed that the reason for this is likely that during electrical breakdown, the carbon black can form a conductive path, which then reduces the BDV in consecutive measurements. In other words, this phenomenon can be described as electrical treeing.The presence of an epoxy potting compound material without carbon black or with a sufficiently low amount of carbon black in an area where there is high stress in the housing (for example, near a die-type electronic component) can therefore be advantageous.

[0062] According to one embodiment, a housing can be provided with a support (such as a conductor frame structure or a ceramic plate with metal layers on opposite main surfaces thereof) on which one or more electronic components (for example, a semiconductor chip) are mounted (for example, by soldering or sintering). An inner encapsulating means, surrounding at least a portion of an electronic component and a support, can be provided with a small quantity of electrically conductive particles, not exceeding 0.1% by weight. Furthermore, an outer encapsulating means, containing a larger quantity (for example, more than 0.1% by weight or more than 0.2% by weight, but less than 1% by weight of the total weight of the outer encapsulating means) of electrically conductive material (in particular, particles), can surround at least a portion of the first encapsulating means.The described combination of an inner and outer encapsulating material with different concentrations of electrically conductive particles can lead to high electrical reliability. The inner, first encapsulating material, containing a small amount of electrically conductive particles (e.g., carbon black particles), can ensure high breakdown voltage and excellent long-term high-voltage stability. Simultaneously, the partial or complete removal of electrically conductive particles from the inner encapsulating material can suppress corrosion inside the housing and thus improve adhesion within the housing. Furthermore, the outer encapsulating material, containing a larger amount of electrically conductive material (e.g., carbon black particles), can improve electrostatic discharge (ESD) protection of the housing without negatively impacting the encapsulated electronic component.

[0063] According to another embodiment, a housing is provided comprising a carrier, an electronic component mounted on the carrier, and an encapsulating means that at least partially encapsulates the electronic component and the carrier, wherein the encapsulating means does not contain any coloring agent (in particular, it does not contain carbon black). Such a housing may have an encapsulating means that contains no electrically conductive particles at all. This can lead to advantageous electrical reliability. In such an embodiment, the encapsulating means may or may not be surrounded by a further encapsulating means.

[0064] In particular, different embodiments may involve a housing without industrial carbon black, a housing core without industrial carbon black or at least without an excessive amount of industrial carbon black and / or other electrically conductive particles.

[0065] One embodiment can provide an enclosure with a colorant-free potting compound, which can improve the enclosure's performance with respect to time-dependent dielectric breakdown (TDDB). TDDB is an important test for various enclosures, such as gate drivers or optocouplers. Furthermore, discrete devices are striving for higher voltage ratings, where similar effects can be important. To ensure that the removal or reduction of carbon black and / or other conductive particles from an enclosure's internal encapsulation material does not compromise the enclosure's reliability, the enclosure can be formed with an inner core potting compound material that is either carbon black-free or contains a sufficiently low amount of carbon black.The inner core potting compound material may be surrounded by an external shell containing industrial carbon black or a larger quantity of industrial carbon black or other electrically conductive particles.

[0066] In one embodiment, a semiconductor package is provided that includes an inner encapsulating material (such as an inner core structure of a potting compound) with a limited amount or even no electrically conductive dye to improve the package's time-dependent dielectric breakdown (TDDB) performance. Accordingly, a semiconductor package can be provided that includes an inner core structure of a potting compound surrounding a die-type electronic component and a second, outer structure. For example, the potting compound of the inner structure does not contain an electrically conductive dye (such as carbon black) or electrically conductive particles, with a limited amount not exceeding 0.1 percent by weight of the total weight of the potting compound of the inner structure.Furthermore, the outer structure can be made from a potting compound containing a significant amount of a colorant (such as carbon black or titanium dioxide), or it can be made from a material other than a potting compound (for example, formed by dipping or coating with a material, paint dipping, etc.). Advantageously, the outer structure can provide effective ESD protection and laser marking capability for the housing.

[0067] In one embodiment, a semiconductor package is provided that contains a potting compound free of electrically conductive particles, carbon black, or a colorant. In such an embodiment, the entire electronic component can be encapsulated with a potting compound that does not contain carbon black.

[0068] In another embodiment, a semiconductor package comprising an inner core structure made of a potting compound without carbon black, or with a limited amount of carbon black or other electrically conductive particles, is provided around an electronic component (for example, of the die type). This can provide high electrical reliability when a high voltage is applied during operation of the package. Furthermore, a second, outer structure can be formed.

[0069] The internal core structure may or may not contain an electrostatic dissipative material. Electrostatic dissipative materials can be in the form of conductive organic or inorganic particles that are covalently or non-covalently (for example, via π-π interactions) bonded to segments of an epoxy backbone to create a spatial distribution and prevent the formation of a long conductive path through particle agglomeration. Electrostatic dissipative materials can also include short conductive chemical groups (CPs) that have reacted with an epoxy component of the potting compound, forming a CP-co-epoxide copolymer or a CP branching off as a side chain of an epoxy backbone.

[0070] The second, outer structure can be provided to offer different properties for the inner shell with regard to color (for example, black) and / or ESD protection of the housing. In this case, the inner core structure can be made of a TDDB-safe and / or high-voltage-resistant material, while the outer shell can provide a connection suitable for laser marking and ESD protection.

[0071] The following are different examples of the latter embodiment. For example, the inner core can be made of an epoxy potting compound without colorant or with a limited amount of colorant or other electrically conductive particles. There are various possibilities for the outer structure: - The outer structure may be made of the same or a different epoxy potting compound as the inner structure, but may additionally contain industrial carbon black, or industrial carbon black or other electrically conductive particles in greater quantity than the inner structure. - The outer structure can be designed as a sealing layer (for example, made from a coating material, etc.). The outer structure can initially be made of the same material as the inner core structure, although its properties can be modified by an additional treatment after potting. Such an additional treatment could, for example, involve exposure to a high-intensity UV (ultraviolet) lamp to carbonize the outer structure. Alternatively, the additional treatment could be a laser treatment that affects the outer structure, for example, initiating an oxidation process that alters the outer layer.

[0072] Overmolding technologies can also be implemented in various designs.

[0073] Although carbon black in an encapsulating material can be advantageous for defining the housing color (especially to make the housing suitable for laser marking) and for ESD protection, it can also negatively affect TDDB performance. Therefore, removing carbon black or limiting its quantity in an area of ​​the housing where a high electric field is present during operation, i.e., in the inner encapsulating material, can be beneficial. However, laser marking on an outer surface of the housing without carbon black can be difficult, and ESD protection may be compromised. To ensure laser marking capability and reliable ESD protection, the outer, additional encapsulating material can contain carbon black or another electrically conductive material (especially particles).

[0074] Therefore, one aspect of an embodiment may be the provision of a semiconductor package in which an epoxy potting compound without carbon black is used in the sensitive high-voltage area of ​​the package (particularly in an inner area) which is covered by an outer layer that provides ESD protection and a laser marking option (for example, an external shell of an epoxy potting compound containing carbon black).

[0075] There are different ways in which a double structure consisting of an inner encapsulating agent (which, for example, does not contain industrial carbon black or other electrically conductive particles, or contains a limited amount of no more than 0.1 percent by weight thereof) and an outer encapsulating agent (which, for example, contains industrial carbon black or other electrically conductive particles, or contains a larger amount of industrial carbon black or other electrically conductive particles than the inner encapsulating agent) is produced.

[0076] For example, the outer encapsulating material can be formed on top of the inner encapsulating material in an additional processing step after potting. This can be achieved, for instance, by dipping or spray coating. Specifically, a potting material of the inner encapsulating material (for example, without carbon black) can undergo heat curing. A thin film of the outer encapsulating material (for example, with carbon black) can then be formed by dipping or spray coating. Optionally, further processing can then be carried out.

[0077] It is also possible to form the outer encapsulating material on top of the inner encapsulating material through an additional processing step after potting, which includes electron beam treatment. After the potting material of the inner encapsulating material (for example, without carbon black) has been formed, the resulting structure can be subjected to heat curing. Subsequently, the outer surface can be irradiated with an electron beam to form a thin, amorphous, carbon-containing film on the surface. Optional post-processing can then be carried out.

[0078] In yet another embodiment, the outer encapsulating material can be formed by phase separation based on hydrophobicity of the inner encapsulating material. In this context, it may be possible to form an epoxy potting compound containing a hydrophobic dye (for example, PDMS (polydimethylsiloxane)-grafted TiO2, hydrophobic carbon black) by potting. A heat curing process can then be carried out. For example, the epoxy and a hydrophobic dye can be separated at an elevated temperature. The hydrophobic dye (for example, PDMS-grafted TiO2) can migrate to the surface while the epoxy is still molten. Optional post-processing can then be performed.

[0079] The following table lists the electrical conductivity of different materials that can form part of a housing: material Electrical conductivity (S / cm) epoxy ~ 10 -9 SiO2 ~ 10 -12 TiO2 <10 - 10 industrial soot 0,1 - 10 2

[0080] For example, carbon black and / or titanium oxide can be used as electrically conductive particles in a housing encapsulator. A highly crystalline petroleum coke, produced (for example) exclusively from blowdown oil from catalytic fluid cracking or coal tar pitch, can also be used as the housing particles described above.

[0081] In one embodiment, the outer encapsulating material (which may, for example, contain carbon black) is produced before the inner encapsulating material (which may not contain carbon black). For example, a cavity housing can be produced with the outer encapsulating material as an outer shell that defines an inner cavity. The cavity can then be filled with the inner encapsulating material.

[0082] For example, in an embodiment where one or more direct copper bonding (DCB) substrates form part of a housing (for example as a carrier and / or further encapsulation means), potting to form the inner encapsulation means can be carried out after die mounting, standoff soldering, etc.

[0083] Fig. Figure 1 illustrates a cross-sectional view 100 of a housing according to an exemplary embodiment.

[0084] The illustrated housing 100 has a support 102, which can, for example, be a conductor frame structure. Such a conductor frame structure can be a structured metallic plate that forms a base 150 for an electronic component 108 described below. The base 150 of the support 102 can be a die pad. Furthermore, the support 102 with the conductor frame structure type can also have one or more lead-in structures 152.

[0085] As already mentioned, the housing 100 has an electronic component 108 mounted on the carrier 102, specifically on its base 150. For example, the electronic component 100 can be a semiconductor die, such as a semiconductor power chip. The electronic component 108 can be mounted on the carrier 102, for example, by soldering, sintering, or gluing. Although this in Fig. Not shown in detail in Figure 1, the electronic component 108 may have one or more electrically conductive pads on one or both of its opposing main surfaces. For example, a pad on an upper surface of the electronic component 108 may be electrically connected to a lead structure 152 by an electrically conductive connection structure 154, such as a bond wire (or alternatively, a clamp not shown).

[0086] Furthermore, the housing 100 comprises an encapsulating agent 110, which here is implemented as a potting compound. Preferably, the encapsulating agent 110 may contain no more than 0.1 percent by weight (preferably no more than 0.05 percent by weight), based on the total weight of the encapsulating agent 110, of electrically conductive particles 104, as shown in Detail 156. In particular, the encapsulating agent 110 may contain electrically conductive particles 104 in the form of carbon black in a range of 0.025 percent by weight to 0.05 percent by weight based on the total weight of the encapsulating agent 110. Detail 156 already mentioned illustrates that only a limited amount of electrically conductive particles 104, such as carbon black particles, is embedded in a matrix 158 of the encapsulating agent 110.The matrix 158 can comprise an epoxy resin, filler particles (for example, aluminum nitride particles to improve electrical conductivity), additives, etc. As shown, the encapsulating agent 110 encapsulates the electronic component 108 and part of the support 102.

[0087] Furthermore, a further encapsulating agent 112 is provided, which covers an outer surface of a portion of the encapsulating agent 110. For example, the further encapsulating agent 112 can be another potting compound. For example, the further encapsulating agent 112 can be formed by overmolding the encapsulating agent 110. Referring to further detail 160, the further encapsulating agent 112 can comprise a larger quantity of electrically conductive material 106 than the encapsulating agent 110. In the embodiment described above, Fig.Figure 1 shows that the electrically conductive material 106 is implemented as further electrically conductive particles, for example, also carbon black. For example, the amount of electrically conductive particles of the further encapsulating agent 112 can be greater than 0.1 percent by weight (preferably at least 0.15 percent by weight) with respect to the total weight of the further encapsulating agent 112. Detail 160 illustrates that a significant amount of electrically conductive particles, such as carbon black particles, is embedded in a further matrix 162 of the further encapsulating agent 112. The matrix 162 can comprise an epoxy resin, filler particles (for example, aluminum nitride particles to improve thermal conductivity), additives, etc.

[0088] Epoxy resin, filler particles and / or additives of the encapsulating agents 110, 112 may be the same or may differ and may be selected according to the requirements of a certain application.

[0089] Advantageously, an inner or core encapsulating material 110 has a limited amount of electrically conductive particles 104. This can lead to increased breakdown voltage, improved long-term high-voltage stability, reduced corrosion, and improved adhesion within the housing 100.

[0090] At the same time, the outer or shell encapsulation material 112 contains a larger quantity of electrically conductive particles, such as carbon black, than the core encapsulation material 110. This can provide ESD protection for the housing 100 and can make an outer surface of the housing 100 suitable for laser marking.

[0091] The described combination configuration of the encapsulating agents 110, 112 can enable the obtaining of the housing 100, which can benefit from the aforementioned advantages in combination.

[0092] Still referring to Fig.In Figure 1, the encapsulating means 110 forms an inner core on the electronic component 108, whereas the further encapsulating means 112 forms an outer shell on at least a part of the inner core. In particular, the encapsulating means 110 is in direct physical contact with the electronic component 108 and with the support 102, whereas the further encapsulating means 112 is not in direct physical contact with the electronic component 108. Furthermore, the further encapsulating means 112 defines a significant part of an outer outline of the housing 100. As shown, a part of the support 102 is exposed beyond the encapsulating means 110 and beyond the further encapsulating means 112.The exposed surface of the carrier 102 can be used to establish an electrical contact with an electronic peripheral and / or to dissipate heat, which is generated in particular by the electronic component 108 during operation of the housing 100.

[0093] The inner core material of the encapsulating agent 110 can, for example, be made of an epoxy potting compound with a limited amount of carbon black or even without carbon black.

[0094] The outer shell of the housing 100, provided by the additional encapsulation material 112, can offer ESD protection and laser marking capability. The outer shell can be made of various materials, for example, a potting compound containing carbon black (so that the encapsulation material 110 and the additional encapsulation material 112 can be formed by double potting). Other materials for the additional encapsulation material 112 include a dipping material, a coating material, a dye bath, etc.

[0095] For example, the additional encapsulating agent 112 can be produced by post-treating an outer part of the encapsulating agent 112 to modify an outer surface (for example, in a way to improve ESD protection and / or to enable laser marking on an outer surface). Such post-treatment can be carried out, for example, during tin plating. Post-treatment for surface modification can also be achieved by a UV lamp, a UV flash, laser treatment, flame treatment, burning, and / or etching.

[0096] In particular, to form the additional encapsulation material 112 as an epoxy potting compound with carbon black, the additional potting compound can be cast onto the encapsulation material 110 after post-treatment. Through two-stage potting, it is possible to form an outer encapsulation shell on an inner encapsulation core with different properties. For example, the additional encapsulation material 112 can be formulated with a higher electrical conductivity than the encapsulation material 110 to improve ESD protection. The additional encapsulation material 112 can also be configured to allow laser marking directly onto it.

[0097] Fig. Figure 2 illustrates a flowchart 200 of a method for manufacturing a housing 100 according to an exemplary embodiment. The reference numerals used for the following description of the manufacturing method relate to the embodiment from Figure 2. Fig.1.

[0098] Referring to a block 202, the method involves mounting an electronic component 108 onto a carrier 102.

[0099] With reference to a block 204, the method includes at least partial encapsulation of the electronic component 108 and the carrier 102 by an encapsulation agent 110 which has no more than 0.1 percent by weight, in relation to a total weight of the encapsulation agent 110, of electrically conductive particles 104.

[0100] Referring to a block 206, the process comprises forming a further encapsulation agent 112 on an outer surface of at least a part of the encapsulation agent 110, wherein the further encapsulation agent 112 comprises a larger quantity of electrically conductive material 106 than the encapsulation agent 110.

[0101] Fig.Figure 3 illustrates a cross-sectional view 100 of a housing according to another embodiment.

[0102] The embodiment according to Fig. 3 differs from the embodiment according to Fig. 1 in that according to Fig. 3 the encapsulating agent 110 does not contain any electrically conductive particles 104 (see detail 164). Another difference between the embodiment from Fig. 3 and the embodiment from Fig. 1 consists in the fact that according to Fig. 3 of the support 102 has a ceramic plate 166 (made, for example, of aluminum oxide or aluminum nitride) which is covered on each opposite main surface by a respective metal layer 168, 170 (for example, a copper layer or an aluminum layer). For example, the support 102 can be Fig.3. The substrate can be a DCB or DAB substrate. The ceramic plate 166 is electrically insulating and thermally conductive. The metal layers 168 and 170 are electrically conductive and thermally conductive. Any of the metal layers 168 and 170 can be continuous or structured. Therefore, the support 102 can have high thermal conductivity and can be able to dissipate heat generated by the electronic component 108 during operation of the housing 100 to a lower side.

[0103] Another difference between the embodiment from Fig. 3 and the embodiment from Fig. 1 is that the embodiment consists of Fig. 3 does not have a second encapsulating agent of the potting type. In contrast, the further encapsulating agent 112 is made of Fig.3, which forms part of an outer surface of the housing 100 and covers part of an outer surface of the encapsulating medium 110, is designed as a further ceramic plate 116 (made, for example, of aluminum oxide or aluminum nitride) which is covered on each opposite main surface thereof by a respective further metal layer 118, 120 (for example, a copper layer or an aluminum layer). For example, the further encapsulating medium 112 can be designed according to Fig. 3. Another DCB substrate or another DAB substrate. Therefore, the additional encapsulating agent 112 is from Fig. 3 as a further support. The further ceramic plate 116 is electrically insulating and thermally conductive. The further metal layers 118, 120 are electrically conductive and thermally conductive. Any of the metal layers 118, 120 can be continuous or structured. Therefore, the further encapsulating agent 112 can be designed according to Fig.3 have a high thermal conductivity and can be able to dissipate heat generated by the electronic component 108 during operation of the housing 100 to a lower side.

[0104] According to Fig. 3 Each of the carrier 102 and the further carrier beyond the encapsulation means 110 is exposed by double-sided cooling for the dissipation of heat generated by the electrical component 108. As can be seen from the foregoing, the configuration consists of Fig. 3. A housing 100 is provided, configured for double-sided cooling, since heat generated by the electronic component 108 can be dissipated through the support 102 to the bottom and through the further encapsulation means 112 to the top of the housing 100. Although this in Fig.Not shown in Figure 3, the upper main surface of the electronic component 108 can optionally be coupled to the lower side of the further encapsulation means 112 by means of a thermally conductive spacer (such as a metal block or a ceramic block).

[0105] Still referring to Fig.3. The inner core material of the encapsulating medium 110 can be an epoxy potting compound without carbon black. The further encapsulating medium 112, which forms an outer shell of the housing 100, is here designed as a DCB that covers the inner core on the top side. Another DCB is provided as the carrier 102 on the bottom side. Although not shown, one or more electronic components 108 (such as electronic chips) can be mounted on either side of the DCBs inside the housing 100, i.e., on the top side of the carrier 102 and / or on the bottom side of the further encapsulating medium 112. It is also possible to use a DAB or an AMB as an alternative to a DCB.

[0106] Fig. Figure 4 illustrates a three-dimensional view of a preform of a housing 100 according to another embodiment. In particular, it shows Fig.3. A conductor frame (which may be a stamped metal plate, for example made of copper) on which one or more electronic chips may be mounted and encapsulated. A suitable external encapsulating material 112 can define a housing color, enable laser writing, and improve ESD protection. Without carbon black, an encapsulating material may have a grayish color.

[0107] Fig. Figure 5 illustrates a component of a housing 100 according to another embodiment. In particular, it shows Fig.5. A plurality of electrically conductive particles 104 (which are made primarily of carbon black). If the amount of carbon black is excessive, the electrically conductive particles 108 of the carbon black type can agglomerate and form continuous electrically conductive paths. This can reduce the breakdown voltage. Consequently, the amount of electrically conductive particles 108, especially in the inner encapsulating material 110 of the core type, should not be too high. Therefore, carbon black can affect the interaction with the surface. Agglomeration can lead to a reduction in electrical reliability. Such an undesirable phenomenon can be prevented by reducing the amount of electrically conductive particles 104 in the inner encapsulating material 110 of the core type.

[0108] Fig. 6 to Fig.8. Diagrams illustrate the effects of exemplary implementations compared to conventional approaches.

[0109] With reference to Fig. Figure 6 shows a diagram 180, which has an abscissa 182 and an ordinate 184. Along the abscissa 182, a series of consecutive measurements on a tested sample for different configurations of an encapsulating agent 110 is plotted. Along the ordinate 184, the dielectric strength (in kV / mm) is plotted. Fig. Figure 6 illustrates the influence of dyes, such as industrial carbon black, on repeated penetration measurements.

[0110] Curve 186 shows a scenario corresponding to a conventional potting-type encapsulation material with a significant amount of industrial carbon black. As shown, the electrical breakdown voltage becomes low after a certain number of measurements.

[0111] Curve 188 shows a scenario corresponding to a potting-type encapsulation material without low-mechanical-stress additives. Curve 188 shows an improvement compared to curve 186. Consequently, one embodiment provides an encapsulation material 110 that does not contain any low-mechanical-stress additive (such as rubber and / or silicone particles).

[0112] Curve 190 shows a scenario corresponding to a potting-type encapsulation material with uncoated filler particles. Curve 190 shows an improvement compared to curve 186. Consequently, one embodiment provides an encapsulation material 110 with filler particles without a coating (see reference numeral 122 in [reference number]). Fig. 9).

[0113] Curve 192 shows a scenario corresponding to a potting-type encapsulation material with titanium oxide as a colorant. Titanium oxide shows a slight improvement compared to carbon black (curve 186).

[0114] Curve 194 illustrates a scenario corresponding to a potting-type encapsulation material without electrically conductive particles, particularly without industrial carbon black. As shown, curve 194 stabilizes at a high breakdown voltage value after numerous measurements. Therefore, the encapsulation material configuration shown in curve 194 is highly advantageous according to one embodiment.

[0115] In summary, the configuration of an internal encapsulation means 110 of a housing 100 of an embodiment without industrial carbon black (or without an excessive amount of industrial carbon black) can provide the following advantages: - Reducing the CTI (Comparative Tracking Index - tracking resistance). To illustrate, the CTI value (in volts) can be a measure of an insulator's electrical breakdown voltage. In short, an enclosure with a higher breakdown voltage can be used or operated at a higher voltage than an enclosure with a lower breakdown voltage. Specifically, analysis shows an improvement in CTI when potting compounds contain a lower concentration of industrial carbon black. This can be deduced from the following table: Industrial carbon black quantity (relative to a reference formulation) 0 % 50 % 75 % 100 % CTI result (average waste) 600 V Waste 91 62 58 55 700 V Waste 63 46 26 <10 800 V Waste 62 27 <10 - - Improving the breakdown voltage (BDV), see Fig. 6. - Increasing adhesion to copper

[0116] Therefore, removing or reducing industrial carbon black from the encapsulating agent 110 can provide some advantages.

[0117] Fig. 7 and Fig. Figure 8 shows the influence of industrial carbon black on TDDB. Accordingly, they state Fig. 7 and Fig. 8 a result of a TDDB study.

[0118] With reference to Fig. Figure 7 shows a diagram 220, which has an abscissa 222 and an ordinate 224. Along the abscissa 222, the time to breakthrough (in seconds) at 25 °C is plotted. Along the ordinate 224, a parameter is plotted that indicates the TDDB. Fig. 7 concerns a load voltage of 3500 V. Each point or data point in diagram 220 indicates a housing that has failed due to electrical breakdown. Fig. Figure 7 shows a scenario corresponding to a conventional potting-type encapsulation material with a significant amount of carbon black. Accordingly, it refers to Fig. 7 on an epoxy potting compound used in a DSO-type enclosure.

[0119] With reference to Fig.Figure 8 shows diagram 230, which corresponds to diagram 220 but represents an epoxy potting compound formulation without carbon black. As in Fig. As shown in Figure 8, not a single failure occurred over a period of approximately 6 months. Therefore, avoiding an excessive amount of electrically conductive particles, such as industrial carbon black, in an encapsulating agent 110 can significantly improve the TDDB behavior.

[0120] Fig. Figure 9 illustrates structures obtained during the manufacture of a housing 100 according to an exemplary embodiment.

[0121] As on the left side of Fig.Figure 9 shows a housing 100 that can be obtained by mounting an electronic component 108 onto a carrier 102. After the electronic component 108 has been electrically connected to a lead structure 152 by means of an electrically conductive connecting element 154, the carrier 102 and the electronic component 108 can be partially encapsulated by an encapsulating means 110. As shown in Detail 195, the encapsulating means 110 comprises Fig. 9 the previously described matrix 158, additives 196 and uncoated filler particles 122 (the latter can improve electrical reliability, as previously described with reference to Fig. (as explained in section 6). However, the encapsulating agent 110 exhibits Fig. 9 no industrial soot.

[0122] As indicated by reference numeral 197, the one on the left can be made from Fig.The structure shown in Figure 9 is then subjected to a further manufacturing step to form the further encapsulation agent 112 as a modified outer surface of a part of the encapsulation agent 110. As shown in Detail 198, the further encapsulation agent 112 has electrically conductive particles 104 in the form of carbon black, in addition to the components of the encapsulation agent 110.

[0123] In the embodiment shown, the further encapsulation medium 112 can be formed based on an outer material of the encapsulation medium 110 by modifying a surface part of the encapsulation medium 110. In particular, carbon black particles can be formed in the further encapsulation medium 112 by carbonization of exposed material of the encapsulation medium 110 induced by ultraviolet (UV) radiation.

[0124] Alternatively, corresponding results can be obtained by treating an outer part of the encapsulating agent 110 by a laser, by an electron beam, by phase separation based on hydrophobicity, by flame treatment, by burning and / or by oxidation.

[0125] Fig. Figure 10 illustrates structures obtained during the manufacture of a housing 100 according to a further embodiment. According to this embodiment, the further encapsulation means 112 is formed before the encapsulation means 110 is formed.

[0126] In Fig.10. The outer encapsulation medium 112 of the DCB type (which may contain a large amount of electrically conductive material 106 in the form of metal layers 118, 120) is produced in front of the inner encapsulation medium 110 (which may not contain any carbon black or may contain a limited amount of carbon black). As shown on the left, a preform with a cavity or void volume 185 can be produced.

[0127] On the left side, the electronic component 108, which is mounted on the carrier 102 and electrically connected to the supply line structure 152 via the electrically conductive connection structure 154, is provided with a thermally conductive spacer 187 mounted on the electronic component 108. The further encapsulation element 112, here a DCB substrate, is mounted on the spacer 187.

[0128] Then (see arrow 189), as on the right side of Fig. 10 shows an encapsulating agent 110 filled by filling the cavity volume 185 with a potting compound, i.e. by potting.

[0129] It should be noted that the term "having" does not exclude other elements or features, and "a" or "an" does not exclude multiple elements. Elements described in association with different embodiments may also be combined. It should also be noted that reference numerals should not be interpreted as limiting the scope of protection of the claims. Furthermore, the scope of protection of the present application should not be limited to the specific embodiments of the process, machine, manufacture, material composition, means, methods, and steps described herein. Accordingly, the appended claims should include such processes, machines, manufactures, material compositions, means, methods, or steps within their scope of protection.

Claims

[1] Housing (100) comprising the following: • a carrier (102); • an electronic component (108) mounted on the carrier (102); • an encapsulating agent (110), ◯ wherein the encapsulating means (110) at least partially encapsulates the electronic component (108) and the carrier (102); ◯ wherein electrically conductive particles (104) are embedded in the encapsulating agent (110); and ◯ wherein the encapsulating agent (110) contains no more than 0.1 percent by weight, with respect to the total weight of the encapsulating agent (110), of electrically conductive particles (104), • a further encapsulation means (112) covering an outer surface of at least part of the encapsulation means (110) and comprising a greater quantity of electrically conductive material (106) than the encapsulation means (110). [2] Housing (100) according to claim 1, comprising one of the following features: wherein the encapsulating agent (110) comprises electrically conductive particles (104), for example carbon black, in a range of 0.025 percent by weight to 0.05 percent by weight with respect to the total weight of the encapsulating agent (110); [3] Housing (100) according to claim 1 or 2, wherein the encapsulating agent (110) comprises not more than 0.05 percent by weight, in relation to the total weight of the encapsulating agent (110), of carbon black as the electrically conductive particles (104). [4] Housing (100) according to one of claims 1 to 3, wherein the electrically conductive material (106) of the further encapsulation means (112) comprises electrically conductive particles, for example carbon black, or comprises at least a metal layer (118, 120). [5] Housing (100) according to any one of claims 1 to 4, wherein the encapsulation means (110) comprises a potting compound. [6] Housing (100) according to any one of claims 1 to 5, wherein the further encapsulation means (112) comprises a potting compound which, for example, comprises carbon black as the electrically conductive material (106). [7] Housing (100) according to any one of claims 1 to 5, wherein the further encapsulation means (112) is a further support, which in particular has a ceramic plate (116) which is covered on both opposite main surfaces thereof with a metal layer (118, 120) as the electrically conductive material (106). [8] Housing (100) according to claim 7, wherein each of the support (102) and of the further support beyond the encapsulation means (110) is exposed by double-sided cooling for the purpose of dissipating heat generated by the electrical component (108). [9] Housing (100) according to any one of claims 1 to 8, wherein the encapsulation means (110) forms an inner core and the further encapsulation means (112) forms an outer shell on at least a part of the inner core. [10] Housing (100) according to any one of claims 1 to 9, wherein the further encapsulation means (112) is configured to provide better protection against electrostatic discharge than the encapsulation means (110). [11] Housing (100) according to any one of claims 1 to 10, wherein the further encapsulation means (112) is configured to enable better laser marking on and / or in it than the encapsulation means (110). [12] Housing (100) according to any one of claims 1 to 11, wherein the encapsulation means (110) is in direct physical contact and the further encapsulation means (112) is not in direct physical contact with the electronic component (108) and / or the carrier (102). [13] Housing (100) according to any one of claims 1 to 12, wherein the further encapsulation means (112) defines part of an outer outline of the housing (100). [14] Housing (100) according to any one of claims 1 to 13, wherein the encapsulation means (110) is configured to provide a higher time-dependent dielectric breakdown safety than the further encapsulation means (112). [15] Housing (100) according to any one of claims 1 to 14, comprising at least one of the following features: wherein the encapsulation means (110) is configured to provide a higher level of high-voltage safety than the further encapsulation means (112); wherein the electrically conductive particles (104) comprise industrial carbon black, titanium oxide and / or crystalline petroleum coke; wherein the electrically conductive particles (104) have an electrical conductivity of at least 0.01 S / cm, specifically at least 0.1 S / cm, in particular in a range of 0.05 S / cm to 500 S / cm; wherein the encapsulating agent (110) does not contain a low-mechanical-stress additive; wherein the encapsulating agent (110) comprises uncoated filler particles (122); wherein part of the carrier (102) is exposed beyond the encapsulation means (110) and beyond the further encapsulation means (112); wherein the encapsulating agent (110) comprises an electrostatic dissipative material, wherein, for example, the electrostatic dissipative material comprises electrically conductive particles bonded to segments of an epoxy backbone of a material of the encapsulating agent (110), and / or short electrically conductive chemical groups that have reacted with epoxy material of the encapsulating agent (110); wherein the electrostatic component (108) comprises a semiconductor chip, for example a power semiconductor chip. [16] Method for manufacturing a housing (100) wherein the method comprises: • Mounting an electronic component (108) on a carrier (102); • at least partial encapsulation of the electronic component (108) and the carrier (102) by an encapsulation means (110), ◯ wherein electrically conductive particles (104) are embedded in the encapsulating agent (110); and ◯ wherein the encapsulating agent (110) comprises no more than 0.1 percent by weight, with respect to the total weight of the encapsulating agent (110), of electrically conductive particles (104); and • Forming a further encapsulation means (112) on an outer surface of at least a part of the encapsulation means (110), wherein the further encapsulation means (112) has a larger amount of electrically conductive material (106) than the encapsulation means (110). [17] The method of claim 16, wherein the method comprises one of the following steps: Formation of the further encapsulation agent (112) by casting onto at least a part of the encapsulation agent (110); Forming the further encapsulation agent (112) by coating at least a part of the encapsulation agent (110), for example by brushing, spraying, depositing and / or dipping. [18] Method according to claim 16, wherein the method comprises forming the further encapsulation means (112) by modifying a surface part of the encapsulation means (110). [19] Method according to claim 18, wherein the modification of the surface part of the encapsulation means (110) is carried out by at least one of the following: Carbonization induced by ultraviolet radiation; Treatment with a laser; Treatment by an electron beam; Phase separation based on hydrophobicity; Flame treatment; Burning; and Oxidize. [20] Method according to any one of claims 16 to 19, wherein the method comprises forming the further encapsulation agent (112) prior to forming the encapsulation agent (110).

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