Patent ID: 12218018

DETAILED DESCRIPTION

Embodiments of a semiconductor device with a reinforcing structure embedded within a volume of encapsulant material are described herein. The reinforcing structure has a tensile strength that is greater than a tensile strength of the encapsulant. Moreover, the reinforcing structure has a textured surface that adheres to the encapsulant, thereby creating a mechanically coupled relationship. As a result, the reinforcing structure advantageously fortifies the encapsulant material, thereby preventing the occurrence of voids or cracks in the encapsulant material. Moreover, the reinforcing structure may be configured to counteract thermal expansion and compression of the encapsulant material, thereby reducing the possibility of delamination of voids occurring between the encapsulant material the encapsulated surfaces.

Referring toFIG.1, a semiconductor module100is depicted, according to an embodiment. The semiconductor module100comprises a carrier102. The carrier102is a substrate that is configured to accommodate the mounting of multiple power semiconductor devices thereon and to efficiently extract heat away from these power semiconductor devices during operation. The carrier102may be configured to be directly mounted to a support structure, such as a heat sink. Alternatively, the carrier102may be attached to a base plate, wherein the base plate is configured to mount the module to an external structure, such as a heat sink. The carrier102comprises a structured metallization layer104disposed on an electrically insulating substrate106. The electrically insulating substrate106may include a ceramic material such as Al2O3(Alumina) AlN (Aluminium Nitride), etc. The structured metallization layer104comprises a plurality of pads that are disposed on the electrically insulating substrate106and are electrically isolated from one another. The pads are dimensioned to accommodate the mounting of semiconductor dies108or passive elements thereon. Additionally, the pads can form part of an electrical interconnect structure that connects two or more devices together. The carrier102may additionally comprise a second metallization layer110disposed on a rear side of the electronics carrier102. The second metallization layer110may be a continuous layer that is used to thermally couple the semiconductor module100to a cooling apparatus, such as a heat sink. The first structured metallization layer104and the second metallization layer110may comprise or be plated with any or more of Cu, Ni, Ag, Au, Pd, Pt, NiV, NiP, NiNiP, NiP/Pd, Ni/Au, NiP/Pd/Au, or NiP/Pd/AuAg.

According to an embodiment, the carrier102is a power electronics carrier, such as a Direct Copper Bonding (DCB) substrate, a Direct Aluminum Bonding (DAB) substrate, or an Active Metal Brazing (AMB) substrate. Further, a power electronics carrier may be an Insulated Metal Substrate (IMS). An Insulated Metal Substrate generally comprises a dielectric insulation layer comprising (filled) materials such as epoxy resin or polyimide, for example. The carrier may also be a printed circuit board (PCB). In that case, the electrically insulating substrate106may comprise a resin material such as FR-4.

The semiconductor module100comprises semiconductor dies108mounted on the carrier102. According to an embodiment, at least one of the semiconductor dies108is configured as a power semiconductor die. A power semiconductor die refers to a single device that is rated to accommodate voltages of at least 100 V (volts), and more typically voltages of 600 V, 1200 V or more and/or is rated to accommodate currents of at least 1 A, and more typically currents of 10 A, 50 A, 100 A or more. Examples of power semiconductor dies include discrete power diodes and discrete power transistor dies, e.g., MOSFETs (Metal Oxide Semiconductor Field Effect Transistors), IGBTs (Insulated Gate Bipolar Transistors), and HEMTs (High Electron Mobility Transistors), etc. Separately or in combination, the semiconductor dies108mounted on the carrier102may comprise other types of devices, e.g., logic devices, custom circuits, controllers, sensing devices, passive elements, etc.

The semiconductor module100may be configured as a power converter or power inverter. For example, the semiconductor dies108may be power transistors that form the high-side switch and low-side switch of a half-bridge circuit. The power module may additionally comprise one or more of the semiconductor dies108being driver dies that control a switching operation of the half-bridge circuit. The power module may additionally include passive devices, e.g., capacitors, inductors, resistors, etc. Electrical interconnection between the various elements on the power electronics substrate106may be effectuated using metal interconnect elements, e.g., clips, ribbons, bond wires, etc., that are soldered to the devices and/or metal pads. Additionally, the semiconductor module100may comprise additional metal structures, such as tabs or busbar structures (not shown) that deliver fixed voltages to the various devices mounted on the on the carrier102.

The semiconductor module100comprises terminal connectors112extending from the carrier102to a location that is externally accessible. The terminal connectors112may be formed from an electrically conductive metal that and may be soldered to or otherwise attached to the carrier102. The terminal connectors112may form external points of electrical contact to the devices mounted on the carrier102. Generally speaking, these terminal connectors112may have a variety of different configurations and may be adapted to mate with a particular receptacle, e.g., a PCB. The terminal connectors112may have a variety of geometric configurations different from what is shown. For example, at least some of the terminal connectors112may be configured as press-fit connectors.

The semiconductor module100comprises a housing114with sidewalls that surround an interior volume over the carrier102. In this context, the interior volume refers to a three-dimensional space that is bounded on one side by the upper surface of the carrier102. Thus, the housing114may form boundaries that in addition to the carrier102enclose the interior volume that is over the carrier102. The sidewalls of the housing114may be attached directly to the carrier102as shown. Alternatively, in another embodiment (not shown), the semiconductor module100may comprise a separate metal baseplate, and the carrier102and the sidewalls of the housing114may each be mounted on this metal baseplate. The housing114may also include a cover section extending over the interior volume. Such a cover section could be integrally formed with the sidewalls, or removably attached thereto. The housing114may be formed from a plastic material, for example.

The semiconductor module100comprises a volume of encapsulant116disposed within the interior volume of the housing114. The encapsulant116protects the components arranged inside the housing114, and in particular encapsulates the semiconductor dies108and associated electrical conditions, thereby protecting these elements from exterior environmental conditions and mechanical damage. Generally speaking, the encapsulant116can comprise any of a wide variety of materials that are used in electronics applications to protect semiconductor dies108. According to an embodiment, the encapsulant116is a dielectric material that electrically isolates the components from one another, and from the potential of a baseplate or other supporting structure to which the carrier102is mounted. For example, the encapsulant116may have a dielectric strength of at least 15 kV/mm and/or a specific resistance of at least 2*1015Ωcm or at least 2.5*1015Ωcm.

According to an embodiment, the encapsulant116is formed from a curable encapsulant material. A curable encapsulant material is a material that can exist in a fluid or gelatinous state and can then be subsequently hardened to form a rigid and/or non-penetrative body. For example, the curable encapsulant116can be in a fluid or gelatinous state during an encapsulation process wherein it is flowed into the interior volume of the housing114. Subsequently, the curable encapsulant116can be hardened to form a substantially rigid structure that encapsulates and protects the components arranged inside the housing114. The hardening may occur through external environmental conditions, e.g., being placed in a heating and/or drying atmosphere and/or exposure to UV radiation or through the application of an external agent. Examples of curable encapsulant materials include epoxy materials, thermosetting plastics, polymers, resins, and pre-preg materials (pre impregnated fiber) such as, FR-4. According to an embodiment, the curable encapsulant116comprises a dielectric gel. More particularly, the curable encapsulant116may be a potting compound, such as a silicone-based potting compound.

The semiconductor module100additionally comprises a reinforcing structure118within the interior volume that is embedded within the volume of encapsulant116. The reinforcing structure118comprises a textured surface. In this context, a textured surface refers to a surface that is intentionally formed with regular or irregular deviations from a single plane and therefore has a greater surface area than a nominally planar surface. The textured surface is accessible by fluid, meaning that the textured surface is either an outer surface of the reinforcing structure118or is an internal surface of the reinforcing structure118that can be accessed by a liquid, e.g., a liquified encapsulant116by the above-described encapsulation process. In the latter case, the internal surface of the reinforcing structure118can be accessed by an open pathway in the reinforcing structure118and/or by diffusion of fluid. The textured surface may interact with the liquified encapsulant material so as to form an adhesive bond between the two.

According to an embodiment, the reinforcing structure118has a tensile strength that is greater than a tensile strength of the curable encapsulant116. In this context, the tensile strength of the curable encapsulant116refers to the tensile strength of the curable encapsulant116in the cured or hardened state. Tensile strength refers to a measurement of the maximum stress that a material can withstand while being stretched or pulled before breaking or undergoing permanent deformation. The tensile strength of the reinforcing structure118and the curable encapsulant116can be measured by standardized engineering tests and equipment.

According to an embodiment, the reinforcing structure118has a coefficient of thermal expansion that is equal to or less than the coefficient of thermal expansion of the curable encapsulant116. For example, the curable encapsulant116may have a coefficient of thermal expansion in the range of 200-600×10−6M/K, which may correspond to the coefficient of thermal expansion of electronics potting compounds. The coefficient of thermal expansion of the reinforcing structure118, which is a function of the underlying materials which form the reinforcing structure118, may be less than 200×10−6M/K and/or may be less than that of the material which forms the curable encapsulant116.

Referring toFIG.2A, an assembly comprising a volume of the curable encapsulant material116without the reinforcing structure118embedded therein is shown. The encapsulant material116is arranged between two fixed plane parallel surfaces120which have a lower coefficient of thermal expansion than the encapsulant116material. The fixed plane parallel surfaces120may correspond to interior surfaces within the housing114. As shown, the encapsulant material116is substantially warped in a central location that is between the fixed plane parallel surfaces120. This warpage results from thermal cycling of the encapsulant116material, e.g., from initial curing of the encapsulant116material or from subsequent thermal cycling of the encapsulant116during operation of the encapsulated devices. The thermal expansion and compression in the encapsulant material116associated with these temperature variations creates a significant amount of tensile stress in the encapsulant material116that is particularly concentrated in the central part of the volume, and at interior surfaces where tensile stresses are not perpendicular thereto, e.g., at protrusions or components extending therefrom.

FIG.2Billustrates the curable encapsulant material116arranged between two fixed plane parallel surfaces120and additionally with the reinforcing structure118embedded within the curable encapsulant116. As can be seen, the presence of the reinforcing structure118substantially mitigates the tensile stress in the material and reduces the amount of warpage in the material. The reinforcing structure118provides a mechanism that more homogeneously distributes tensile stress that arises in the encapsulant material116throughout the entire volume of the encapsulant material116. This is due to the increased tensile strength of the material of the reinforcing structure118and the mechanical coupling of the textured surface to the curable encapsulant material116. Moreover, the reinforcing structure118can provide a mechanism that counteracts the thermal expansion and compression of the curable encapsulant material116. This is due to the lower coefficient of thermal expansion of the reinforcing structure118.

Referring again toFIG.1, the reinforcing structure118enhances the efficacy of the encapsulant material116and reliability of the semiconductor module100in the following way. The encapsulant material116may initially be flowed at a temperature of between 50° C. and 200° C. and subsequently brought to room temperature. Separately or in combination, during operation, the heat generating elements of the semiconductor module100such as the semiconductor dies108and/or passive elements may reach operating temperatures of 50° C., 75° C., 100° C., 150° C., 200° C. or more. The increased tensile strength of the encapsulant material116mitigates the possibility of cracks or breaks forming in the encapsulant material116at any time during these thermal cycles, thereby ensuring reliable encapsulation of the devices. Separately or in combination, the reinforcing structure118reduces the degree to which the encapsulant material116compresses or expands during these thermal cycles. This reduces the possibility of voiding or delamination between the interior surfaces of the semiconductor module100, such as the surfaces of the metallization and the semiconductor dies108mounted on the carrier102. As a result, the reinforcing structure118may eliminate the need to apply specific adhesion promotors to the surfaces of the metallization and the semiconductor dies108prior to encapsulation. Separately or in combination, the reinforcing structure118may allow for smaller design rule spacings between the internal elements of the power module, such as between busbar structures, interconnect elements, connectors, etc.

Referring toFIG.3A, one embodiment of the reinforcing structure118is shown. In this embodiment, the reinforcing structure118is a cubic-shaped object that comprises a network of cells. That is, the reinforcing structure118occupies a fixed volume and comprises a plurality of cells that are contained within the interior volume of the reinforcing structure118. The cells are cavities or pores in the reinforcing structure118that can accommodate a volume of fluid therein.

According to an embodiment, the reinforcing structure118is configured such that the network of cells of the reinforcing structure118form a three-dimensional grid. This means that the cells are arranged along a first plane and are arranged along a second plane that is orthogonal to a first plane. Examples of reinforcing structures118which form a form a three-dimensional grid include foams and sponges. Other examples of reinforcing structures118which form a three-dimensional grid include technical filters and three-dimensional textiles. The three-dimensional grid arrangement is well-suited to homogenously distribute the tensile stress throughout the entire volume of the encapsulant material116. This is because the arrangement of the cells relegates the area of tensile stress to evenly distributed and mechanically decoupled locations.

According to an embodiment, a reinforcing structure118that comprises a network of cells is configured such that there is open fluid ingress and egress to the network of cells. That is, a fluid, such as a liquefied encapsulant116, can reach the interior cells though a network of channels or pores. Examples of reinforcing structures118that are configured such that there is open fluid ingress and egress to the network of cells include open-cell sponges and foams, as well as technical filters and three-dimensional textiles. Alternatively, it may be possible for the reinforcing structure118to compose a closed network of cells wherein a liquefied encapsulant116reaches the cells by diffusion, depending on factors such as the thickness and material composition of the reinforcing structure118and the viscosity of the encapsulant116.

Referring toFIG.3B, another embodiment of the reinforcing structure118is shown. In this embodiment, the reinforcing structure118is a woven fabric. The woven fabric comprises strands of dielectric material that are woven together in transverse directions. Different to the three-dimensional grid described above, the woven fabric may not necessarily comprise cells. In this case, the surface interaction between the woven fabric and the curable encapsulant material116creates adherence and mechanically couples the curable encapsulant116to the reinforcing structure118. Multiple sheets of the woven fabric may be used together in a single volume of the curable encapsulant material116to enhance the structural integrity.

Referring toFIG.3C, another embodiment of the reinforcing structure118is shown. In this embodiment, the reinforcing structure118is a plurality of disconnected filler elements. Each of the disconnected filler elements may be flake-like structures with a textured surface. The disconnected filler elements may comprise perforations or may be a continuous object. The geometry of the disconnected filler elements can be random and/or non-identical as between two filler elements. The disconnected filler elements can be immersed in the encapsulant116. In the aggregate, the incorporation of a plurality of disconnected filler elements into the curable encapsulant116can enhance the tensile strength of the encapsulant116in comparison to a volume of the encapsulant116without the filler elements.

In any of the above-described examples, the material which forms the reinforcing structure118can be any material that can create the necessary geometry while also conforming to tensile strength requirements and/or coefficient of thermal expansion requirements, as the case may be. The material which forms the reinforcing structure118can be a dielectric material such that the encapsulant116with the reinforcing structure118has the necessary electrical isolation properties. Examples of materials that can satisfy this criterion include thermoplastic materials, epoxy materials duroplastics, elastomers and silicone materials, for example.

The reinforcing structures118disclosed with reference toFIGS.3A,3B and3Cmay be combined within one another in a single volume of curable encapsulant116to enhance. For example, a cubic-shaped object as described with reference toFIG.3Amay be immersed in a curable encapsulant116comprising the disconnected filler elements as described with reference toFIG.3Cmixed therein. In another example, a woven fabric as described with reference toFIG.3Bmay be immersed in a curable encapsulant116comprising the disconnected filler elements as described with reference toFIG.3Cmixed therein.

Referring toFIG.4A, a method of producing a semiconductor module100comprises providing the carrier102comprising a structured metallization layer104disposed on an electrically insulating substrate106, mounting a semiconductor die108on the carrier102and providing a housing114that surrounds an interior volume over the carrier102. The semiconductor die108can be mounted on the structured metallization layer104using a conductive adhesive such as solder. The electrical interconnect elements, e.g., bond wires, clips, ribbons, etc., may be attached using conductive adhesives such as solder or other bonding methods such as welding technologies. Subsequently, the reinforcing structure118can be placed within the interior volume of the housing114, e.g., in the case of a cubic-shaped object that comprises a network of cells or a woven fabric. The reinforcing structure118may be designed to fit around the electrical interconnect elements or the electrical interconnect elements may deform the reinforcing structure118. For example, as shown, the reinforcing structure118may comprise a slit or opening to accommodate wire bonds (as shown inFIG.1), while being planar and flush against the structured metallization layer104in different cross-sections (as shown inFIGS.4A and4B).

Referring toFIG.4B, the curable encapsulant116is provided within the interior volume such that the semiconductor die108is encapsulated and such that the reinforcing structure118is embedded within the encapsulant116. This process may comprise flowing the curable encapsulant116into the interior volume in a liquified state so as to cover the semiconductor die108and interact with the textured surface area of the reinforcing structure118. Subsequently, the encapsulant116is hardened such that the reinforcing structure118is inseparable from the curable encapsulant116.

In an embodiment wherein the reinforcing structure118is a cubic-shaped object that comprises a network of cells, the encapsulation process may be carried out such that the cells absorb the liquified encapsulant116. To this end, the cells may be dimensioned to permit the liquefied state encapsulant116to flow into them during the flowing of the curable encapsulant116. The ability of the cells to absorb the liquefied state encapsulant116can be a function of the volume of the cells, the degree of open ingress and egress between the cells and the exterior environment, and the viscosity of the liquefied state encapsulant116. Accordingly, these variables may be selected to ensure that the liquefied state encapsulant116is mostly absorbed (e.g., at least 75% of capacity) in a commercially reasonable about of time. Separately or in combination, the atmospheric conditions may be selected to enhance absorption. For example, the curable encapsulant116can be flowed by a vacuum potting process whereby interior volume of the housing114is in a very low-pressure atmosphere. This removes air from the cells of the reinforcing structure118and allows for easier displacement of the liquified encapsulant116into the cells.

According to another technique a structure comprising the reinforcing structure118and an encapsulant116such as a curable dielectric gel is hardened is prepared outside of the interior volume. This prepared structure with the hardened encapsulant116is then arranged within the interior volume. Subsequently, a second liquified encapsulant116is flowed into the interior volume to fill the areas between the prepared structure and the housing114.

Referring toFIG.5, a semiconductor package200is depicted, according to an embodiment. Generally speaking, the semiconductor package200can have a wide variety of configurations, e.g., discrete device package, integrated device, etc. The semiconductor package200can comprise a metal lead frame202with a die pad and a plurality of leads extending away from the die pad. A semiconductor die108is mounted on the lead frame202and is electrically connected to the leads using electrical interconnect elements, e.g., wire bonds as shown.

The semiconductor package200comprises an encapsulant body204of encapsulant material116. The encapsulant body204can be formed by a molding process such as injection molding, transfer molding, compression molding, etc. According to these techniques, a lead frame assembly comprising the lead frame202with the semiconductor die mounted108thereon is arranged into a molding tool, a mold compound is injected into the molding tool and is subsequently cured to form the encapsulant body204. Generally speaking, the mold compound can comprise dielectric materials such as epoxy, thermosetting plastic, polymer, resin, etc.

The semiconductor device additionally comprises a reinforcing structure118contained within the encapsulant body204and arranged between the semiconductor die108and an outer surface206of the encapsulant body204. The reinforcing structure118can comprise any one or combination of the previously described embodiments. As shown, the reinforcing structure118is a cubic-shaped object that comprises a network of cells. This reinforcing structure118can be arranged over the semiconductor die prior to the mold injection process such that a liquified encapsulant material flows into and is absorbed by the reinforcing structure118in a similar manner as previously described. The reinforcing structure118advantageously mitigates cracking and mechanical failure as well as the formation of voids of delamination within the semiconductor package200in the same way as previously described.

A reinforcing structure118as described herein can be incorporated into a variety of different types of curable materials used in electronics applications. Examples of these curable materials include adhesive compounds, sealings, electrically conductive gels. In the case of an electrically conductive curable materials, the material composition of the reinforcing structure118can be selected accordingly.

Although the present disclosure is not so limited, the following numbered examples demonstrate one or more aspects of the disclosure.

Example 1

A semiconductor module, comprising: a power electronics carrier comprising a structured metallization layer disposed on an electrically insulating substrate; a power semiconductor die mounted on the power electronics carrier; a housing comprising sidewalls that surround an interior volume over the power electronics carrier; a reinforcing structure contained within the interior volume and comprising a textured surface that is accessible by fluid; a volume of curable encapsulant disposed within the interior volume and encapsulating the power semiconductor die, wherein the reinforcing structure is embedded within the volume of curable encapsulant such that the textured surface adheres to the encapsulant, wherein the reinforcing structure has a tensile strength that is greater than a tensile strength of the curable encapsulant, and wherein the reinforcing structure comprises a material with a coefficient of thermal expansion that is equal to or less than a coefficient of thermal expansion of the encapsulant.

Example 2

The semiconductor module of example 1, wherein the reinforcing structure comprises a network of cells, and wherein the cells at least partially absorb the encapsulant.

Example 3

The semiconductor module of example 2, wherein the cells form a three-dimensional grid.

Example 4

The semiconductor module of example 3, wherein the reinforcing structure is an foam or sponge.

Example 5

The semiconductor module of example 3, wherein the reinforcing structure comprises any one or more of: duroplastics, elastomers, and silicone.

Example 6

The semiconductor module of example 1, wherein the reinforcing structure comprises any one or more of: a woven fabric, and a plurality of disconnected filler elements.

Example 7

The semiconductor module of example 1, wherein the curable encapsulant and the reinforcing structure are each formed from dielectric materials.

Example 8

The semiconductor module of example 7, wherein the curable encapsulant is a silicone-based potting compound.

Example 9

The semiconductor module of example 1, wherein the reinforcing structure has a lower coefficient of thermal expansion than the encapsulant.

Example 10

A semiconductor device, comprising: an encapsulant body of electrically insulating encapsulant material; a semiconductor die encapsulated within the encapsulant body; and a reinforcing structure contained within the encapsulant body and arranged between the semiconductor die and an outer surface of the encapsulant body, wherein the reinforcing structure comprises a textured surface area that is accessible by fluid, wherein the reinforcing structure is embedded within the encapsulant body such that the textured surface adheres to the encapsulant material, and wherein the reinforcing structure has a tensile strength that is greater than a tensile strength of the curable encapsulant, and wherein the reinforcing structure comprises a material with a coefficient of thermal expansion that is equal to or less than a coefficient of thermal expansion of the encapsulant.

Example 11

The semiconductor device of example 10, wherein the reinforcing structure comprises a network of cells, wherein the cells at least partially absorb the encapsulant, and wherein the cells form a three-dimensional grid.

Example 12

A method of producing a semiconductor module, the method comprising: providing a power electronics carrier comprising a structured metallization layer disposed on an electrically insulating substrate; mounting a power semiconductor die on the power electronics carrier; providing a housing comprising sidewalls that surround an interior volume over the power electronics carrier; providing a reinforcing structure within the interior volume that comprises a textured surface area; and providing a curable encapsulant disposed within the interior volume that encapsulates the power semiconductor die, wherein the reinforcing structure is embedded within volume of curable encapsulant such that the textured surface area adheres to the encapsulant, wherein the reinforcing structure has a tensile strength that is greater than a tensile strength of the curable encapsulant, and wherein the reinforcing structure comprises a material with a coefficient of thermal expansion that is equal to or less than a coefficient of thermal expansion of the encapsulant.

Example 13

The method of example 12, wherein the reinforcing structure is provided within the interior volume before providing the curable encapsulant, and wherein providing the curable encapsulant comprises: flowing the curable encapsulant in a liquified state into the interior volume so as to cover the power semiconductor die and interact with the textured surface area; and hardening the encapsulant such that the reinforcing structure is inseparable from the curable encapsulant.

Example 14

The method of example 13, wherein the reinforcing structure comprises a network of cells, and wherein the cells are dimensioned to permit the liquefied state encapsulant to flow into them during the flowing of the curable encapsulant.

Example 15

The method of example 14, wherein the cells form a three-dimensional grid.

Example 16

The method of example 13, wherein the reinforcing structure distributes the curable encapsulant into a plurality of distributed regions that permit compression and expansion of the encapsulant during thermal cycling.

Example 17

The method of example 16, wherein the power semiconductor die has a maximum operating temperature of at least 75° C.

Example 18

The method of example 12, wherein the curable encapsulant comprises a dielectric gel.

Example 19

The semiconductor module of example 19, wherein the dielectric gel is a silicone-based potting compound.

The semiconductor dies108disclosed herein can be formed in a wide variety of device technologies that utilize a wide variety of semiconductor materials. Examples of such materials include, but are not limited to, elementary semiconductor materials such as silicon (Si) or germanium (Ge), group IV compound semiconductor materials such as silicon carbide (SiC) or silicon germanium (SiGe), binary, ternary or quaternary III-V semiconductor materials such as gallium nitride (GaN), gallium arsenide (GaAs), gallium phosphide (GaP), indium phosphide (InP), indium gallium phosphide (InGaPa), aluminum gallium nitride (AlGaN), aluminum indium nitride (AlInN), indium gallium nitride (InGaN), aluminum gallium indium nitride (AlGaInN) or indium gallium arsenide phosphide (InGaAsP), etc.

The semiconductor dies108disclosed herein may be configured as a vertical device, which refers to a device that conducts a load current between opposite facing main and rear surfaces of the die. Alternatively, the semiconductor dies108may be configured as a lateral device, which refers to a device that conducts a load current parallel to a main surface of the die.

Spatially relative terms such as “under,” “below,” “lower,” “over,” “upper” and the like, are used for ease of description to explain the positioning of one element relative to a second element. These terms are intended to encompass different orientations of the device in addition to different orientations than those depicted in the figures. Further, terms such as “first,” “second,” and the like, are also used to describe various elements, regions, sections, etc. and are also not intended to be limiting. Like terms refer to like elements throughout the description.

As used herein, the terms “having,” “containing,” “including,” “comprising” and the like are open-ended terms that indicate the presence of stated elements or features, but do not preclude additional elements or features. The articles “a,” “an” and “the” are intended to include the plural as well as the singular, unless the context clearly indicates otherwise.

With the above range of variations and applications in mind, it should be understood that the present invention is not limited by the foregoing description, nor is it limited by the accompanying drawings. Instead, the present invention is limited only by the following claims and their legal equivalents.