The instant disclosure relates to a semiconductor module arrangement.
Power semiconductor module arrangements often include at least one substrate arranged in a housing. A semiconductor arrangement including a plurality of controllable semiconductor elements (e.g., IGBTs, MOSFETs, HEMTs, etc.) may be arranged on each of the at least one substrate. Each substrate usually comprises a substrate layer (e.g., a ceramic layer), a first metallization layer deposited on a first side of the substrate layer, and a second metallization layer deposited on a second side of the substrate layer. The controllable semiconductor elements are mounted, for example, on the first metallization layer which usually is a structured layer. That is, the first metallization layer is not a continuous layer, but includes recesses between different sections of the layer. A size and shape of the individual sections generally depends on different aspects such as, e.g., specific design specifications. Due to the overall cost of a power semiconductor module, it is generally not desirable to significantly increase the size of a substrate. If integration density increases while keeping the size of the substrate as small as possible, however, the current density may significantly increase in at least some sections of the first metallization layer, especially in areas providing a comparably small cross-sectional area for the current to flow through.
There is a need for a power semiconductor module arrangement that provides an increased current carrying capacity, and that can be produced easily and at low costs.
A power semiconductor module arrangement includes a substrate including a dielectric insulation layer, and a first metallization layer arranged on a first surface of the dielectric insulation layer, at least one semiconductor body arranged on and attached to the first metallization layer by means of an electrically conductive connection layer, and at least one electrically conducting element arranged on the first metallization layer, wherein the first metallization layer is a structured layer including a plurality of different sub-sections, the first metallization layer has a uniform thickness in a vertical direction, wherein the vertical direction is perpendicular to the first surface of the dielectric insulation layer, each of the at least one electrically conducting element is arranged on and covers a subarea of a sub-section, thereby increasing the cross-sectional area of the subarea of the respective sub-section, and each of the at least one electrically conducting element includes an electrically conductive connection layer without a semiconductor body arranged thereon.
A method for forming a power semiconductor module arrangement includes attaching at least one semiconductor body to a first metallization layer of a substrate including a dielectric insulation layer and the first metallization layer, by means of an electrically conductive connection layer, and forming at least one electrically conducting element on the first metallization layer, wherein the first metallization layer is a structured layer including a plurality of different sub-sections, the first metallization layer has a uniform thickness in a vertical direction, wherein the vertical direction is perpendicular to the first surface of the dielectric insulation layer, each of the at least one electrically conducting element is formed on and covers a subarea of a sub-section, thereby increasing the cross-sectional area of the subarea of the respective sub-section, and each of the at least one electrically conducting element includes an electrically conductive connection layer without a semiconductor body arranged thereon.
The invention may be better understood with reference to the following drawings and the description. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like referenced numerals designate corresponding parts throughout the different views.
In the following detailed description, reference is made to the accompanying drawings. The drawings show specific examples in which the invention may be practiced. It is to be understood that the features and principles described with respect to the various examples may be combined with each other, unless specifically noted otherwise. In the description, as well as in the claims, designations of certain elements as “first element”, “second element”, “third element” etc. are not to be understood as enumerative. Instead, such designations serve solely to address different “elements”. That is, e.g., the existence of a “third element” does not require the existence of a “first element” and a “second element”. An electrical line or electrical connection as described herein may be a single electrically conductive element, or include at least two individual electrically conductive elements connected in series and/or parallel. Electrical lines and electrical connections may include metal and/or semiconductor material, and may be permanently electrically conductive (i.e., non-switchable). A semiconductor body as described herein may be made from (doped) semiconductor material and may be a semiconductor chip or be included in a semiconductor chip. A semiconductor body has electrically connecting pads and includes at least one semiconductor element with electrodes.
Referring to
Each of the first and second metallization layers 111, 112 may consist of or include one of the following materials: copper; a copper alloy; aluminum; an aluminum alloy; any other metal or alloy that remains solid during the operation of the power semiconductor module arrangement. The substrate 10 may be a ceramic substrate, that is, a substrate in which the dielectric insulation layer 11 is a ceramic, e.g., a thin ceramic layer. The ceramic may consist of or include one of the following materials: aluminum oxide; aluminum nitride; zirconium oxide; silicon nitride; boron nitride; or any other dielectric ceramic. For example, the dielectric insulation layer 11 may consist of or include one of the following materials: Al2O3, AlN, SiC, BeO or Si3N4. For instance, the substrate 10 may, e.g., be a Direct Copper Bonding (DCB) substrate, a Direct Aluminum Bonding (DAB) substrate, or an Active Metal Brazing (AMB) substrate. The substrate 10 may also be a conventional printed circuit board (PCB) having a non-ceramic dielectric insulation layer 11. For instance, a non-ceramic dielectric insulation layer 11 may consist of or include a cured resin.
The substrate 10 is arranged in a housing 7. In the example illustrated in
One or more semiconductor bodies 20 may be arranged on the at least one substrate 10. Each of the semiconductor bodies 20 arranged on the at least one substrate 10 may include a diode, an IGBT (Insulated-Gate Bipolar Transistor), a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), a JFET (Junction Field-Effect Transistor), a HEMT (High-Electron-Mobility Transistor), and/or any other suitable semiconductor element.
The one or more semiconductor bodies 20 may form a semiconductor arrangement on the substrate 10. In
The power semiconductor module arrangement 100 illustrated in
The power semiconductor module arrangement 100 may further include an encapsulant 5. An encapsulant 5 may consist of or include a silicone gel or may be a rigid molding compound, for example. The encapsulant 5 may at least partly fill the interior of the housing 7, thereby covering the components and electrical connections that are arranged on the substrate 10. The terminal elements 4 may be partly embedded in the encapsulant 5. At least their second ends 42, however, are not covered by the encapsulant 5 and protrude from the encapsulant 5 through the housing 7 to the outside of the housing 7. The encapsulant 5 is configured to protect the components and electrical connections of the power semiconductor module 100, in particular the components arranged on the substrate 10 inside the housing 7, from certain environmental conditions and mechanical damage.
Now referring to
Depending on the specific application a power semiconductor module arrangement is used in, more sub-sections of the first metallization layer 111, more semiconductor bodies 20, more terminal elements and more electrical connections may be required. The layout of a power semiconductor module arrangement, therefore, may be very specific. In order to keep the overall size of the substrate 10 as small as possible, due to cost reasons, the different sub-sections of the metallization layer may be comparably small in size. Even further, at least some of the sub-sections may have irregular forms. However, some applications require that comparably large currents flow through at least some of the sub-sections of the first metallization layer 111. If integration density of a power semiconductor module arrangement increases while keeping the size of the substrate as small as possible, however, the current density may significantly increase in some sub-sections of the first metallization layer, especially in areas providing a comparably small cross-sectional area for the current to flow through.
Now referring to
Now referring to
That is, the one or more semiconductor bodies 20 may be mounted to the first metallization layer 111 by means of a solder layer comprising or consisting of a first material, e.g., PbSnAg (or any other suitable material commonly used for soldering). Each of the at least one electrically conducting element 80 may comprise a solder layer comprising or consisting of the same first material. This allows to form all electrically conductive connection layers 30 at the same time. In particular, when the one or more semiconductor bodies 20 are soldered to the first metallization layer 111, the one or more electrically conducting elements 80 may be formed at the same time. The one or more semiconductor bodies 20 may be arranged on the first metallization layer 111 with an electrically conductive connection layer 30 arranged between each of the one or more semiconductor bodies 20 and the first metallization layer 111. The electrically conductive connection layers 30 of the one or more electrically conducting elements 80 may be formed at the same time, without a semiconductor body 20 arranged thereon. In a next step, the arrangement may be heated, thereby attaching the one or more semiconductor bodies 20 to the first metallization layer 111. During the heating step, the electrically conductive connection layers 30 of the one or more electrically conducting elements 80 will melt as well. The same applies when the electrically conductive connection layers 30 are all sinter layers, for example.
In the example illustrated in
It is generally possible that a power semiconductor module arrangement only comprises one or more electrically conducting elements 80 as illustrated in
The thickness d80 of the at least one electrically conducting element 80 in the vertical direction y may be at least 10 μm, or at least 50 μm. A certain minimum thickness is generally required in order to result in a noticeable effect of the electrically conducting elements 80 (increase of thickness is large enough to noticeably increase the current carrying capability of the respective subarea). The electrically conducting elements 80 may generally have any thickness above this minimum thickness.
A width w80 of an electrically conducting element 80 may correspond to the width of the respective subarea of the first metallization layer 111 it is arranged on. As is schematically illustrated in
Each of the one or more electrically conducting elements 80 may be arranged on a subarea of the first metallization layer 111, for which an increase of its cross-sectional area is desired. This may apply for very narrow subareas that need to conduct large currents. However, even some broader subareas may benefit from an electrically conducting element 80 arranged thereon. By increasing the cross-sectional area of subareas of the structured first metallization layer 111, the overall lifetime of the power semiconductor module arrangement may be significantly increased, as the current density in the concerned subareas may be significantly decreased.
Terms such as “first”, “second”, and the like, are 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.
The expression “and/or” should be interpreted to cover all possible conjunctive and disjunctive combinations, unless expressly noted otherwise. For example, the expression “A and/or B” should be interpreted to mean only A, only B, or both A and B. The expression “at least one of” should be interpreted in the same manner as “and/or”, unless expressly noted otherwise. For example, the expression “at least one of A and B” should be interpreted to mean only A, only B, or both A and B.
It is to be understood that the features of the various embodiments described herein may be combined with each other, unless specifically noted otherwise.
Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this invention be limited only by the claims and the equivalents thereof.
Number | Date | Country | Kind |
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23160942.1 | Mar 2023 | EP | regional |