DC Solid State Switches

Abstract

The switch assembly includes a housing and a direct current (DC) electronic solid-state switch coupled to the housing. The housing covers the DC electronic solid-state switch, which has an on state and an off state. The DC electronic solid-state switch blocks between 650 volts and 1200 volts in a single direction in the off state. The DC electronic solid-state switch continuously carries at least 400 amperes of direct current with a voltage drop of less than one volt. The DC electronic solid-state switch also includes a plurality of semiconductor tube cores, each semiconductor tube core forming a MOSFET. The DC electronic solid-state switch also includes a plurality of signal conductors.

Description

Technical Field

[0001] The present disclosure relates to electrical components and, more particularly, to direct current (DC) electronic solid state switches and assemblies. Background Art

[0002] Existing high voltage, high current electromechanical relays are bulky (i.e., have a mass greater than 0.5 kg), have slow switching speeds (i.e., have switching speeds greater than 10 ms), and are susceptible to contact welding due to contact bounce during high current switching. In addition, existing electromechanical relays produce audible noise during switching that is unpleasant to customers. Therefore, there is a need to develop a switch that is lightweight, has fast switching speeds, and is quiet. Summary of the invention

[0003] The present disclosure relates to DC electronic solid-state switches. The switch assembly of the present disclosure is lightweight, has fast switching speeds, and is quiet. In addition, the DC electronic solid-state switch of the present disclosure achieves the following desired benefits, namely: continuously delivers at least 400 amperes of DC with a voltage drop of less than one volt; has 50% less power loss than IGBTs; is scalable; has fast fault interruptibility; has fault current limiting, improves repeatability and reliability; has no arc pinning or extinguishing; has intelligent power control; and a custom package.

[0004] In one aspect of the present disclosure, a switch assembly includes a housing and a direct current (DC) electronic solid-state switch coupled to the housing. The housing covers the DC electronic solid-state switch, which has an on state and an off state. The DC electronic solid-state switch may include a substrate, an electrically insulating thermally conductive layer disposed on the substrate, and a first conductive trace disposed on the electrically insulating thermally conductive layer. The first conductive trace forms a positive terminal. The DC electronic solid-state switch also includes a second conductive trace disposed on the electrically insulating thermally conductive layer. The second conductive trace forms a negative terminal. The DC electronic solid-state switch also includes a plurality of semiconductor dies, each of which is disposed on the first conductive trace. Each of the plurality of semiconductor dies forms a MOSFET or an IGBT or other type of electronically controllable switch, which can be manufactured by a standard semiconductor processing method. The DC electronic solid-state switch also includes a first plurality of electrical junctions, each connected to a corresponding one of the plurality of semiconductor dies. Each of the first plurality of electrical junctions electrically interconnects the plurality of semiconductor dies and the second conductive trace. The DC electronic solid-state switch also includes a plurality of signal conductors disposed on the electrically insulating thermally conductive layer and a second plurality of electrical junctions electrically connecting the plurality of signal conductors to the plurality of semiconductor dies. The DC electronic solid state switch blocks between 650 volts and 1200 volts in a single direction in an off state, and the DC electronic solid state switch continuously carries at least 400 amperes direct current with a voltage drop of less than one volt in an on state.

[0005] The substrate may have a thickness between two millimeters and three millimeters, and the plurality of semiconductor dies may be electrically connected to each other in parallel. The switch assembly may further include a solder layer disposed between the substrate and the electrically insulating heat-conducting layer to connect the substrate to the electrically insulating heat-conducting layer. The housing may include a polymer material. The electrically insulating heat-conducting layer may include a ceramic material. The substrate may include copper, aluminum, molybdenum, or an alloy thereof, or a metal-based composite material, such as AlSiC. The solder layer may be directly coupled to the substrate. Each of the substrate, the electrically insulating heat-conducting layer, and the solder layer may have a planar shape.

[0006] Each of the first conductive trace and the second conductive trace can be directly coupled to the electrically insulating thermally conductive layer. Each of the first conductive trace and the second conductive trace can be directly bonded to the electrically insulating thermally conductive layer. Each of the plurality of signal conductors can be directly coupled to the electrically insulating thermally conductive layer. Each of the plurality of signal conductors can be directly bonded to the electrically insulating thermally conductive layer. Each of the plurality of signal conductors, the first conductive trace and the second conductive trace can include a metal material, such as copper or aluminum and alloys thereof.

[0007] Each of the plurality of semiconductor dies may have a minimum area of ​​twenty square millimeters. Each of the plurality of semiconductor dies may include a semiconductor material. The semiconductor material may be silicon, silicon carbide, and gallium nitride. The plurality of semiconductor dies may include between four and sixteen semiconductor dies connected in parallel to carry a current of 400A. Each of the first plurality of electrical bonds may be a ribbon bond or a wire bond. Each of the second plurality of electrical bonds may be a wire bond.

[0008] Each of the first conductive trace and the second conductive trace can be directly coupled to the electrically insulating thermally conductive layer. The switch assembly can include four to sixteen semiconductor dies, and each of the semiconductor dies can have a specific on-resistance of less than 3.5 to 4.5 mΩ-cm 2 The switch assembly may have a maximum width of 55 to 65 mm, a maximum length of 65 mm, and a maximum height of 25 mm. The switch assembly may also include a plurality of thermistors coupled to the signal conductors. The isolation resistance of the switch assembly may be greater than 50 megohms. The DC electronic solid state switch may have a mass equal to or less than 250 grams and an on / off time of less than 10 microseconds.

[0009] The switch assembly may also include a metal sheet, wherein the electrically insulating thermally conductive layer is directly bonded to the metal sheet. The metal sheet and the electrically insulating thermally conductive layer may together form a directly bonded substrate. The metal sheet includes metals such as copper and aluminum.

[0010] The DC electronic solid-state switch is capable of continuously carrying a scalable current with a low on-state resistance in an on state, and the semiconductor die is capable of blocking direct current between at least 650V and 1200V. The spacing between adjacent semiconductor dies may be greater than one millimeter and less than three millimeters. The switch assembly may also include a heat sink directly coupled to the substrate. The heat sink may include a heat sink and a plurality of pin-shaped heat sinks protruding from the heat sink. The substrate has a maximum thickness between two millimeters and three millimeters.

[0011] The switch assembly may further include a thermal interface material disposed between the heat sink and the substrate. The maximum thickness of the thermal interface material may be 0.1 mm. The maximum thickness of the substrate may be 2 mm.

[0012] The switch assembly may further include a metal sheet. The electrically insulating thermally conductive layer may be directly bonded to the metal sheet. The maximum thickness of the metal sheet may be 0.3 mm. The maximum thickness of the electrically insulating thermally conductive layer may be between 0.1 mm and 0.4 mm. The maximum thickness of each of the first conductive trace and the second conductive trace may be between 0.3 mm and 0.8 mm. The maximum thickness of each semiconductor die may be 0.2 mm.

[0013] The present application may also include the following schemes.

[0014] 1. A switch assembly, comprising:

[0015] case;

[0016] A direct current (DC) electronic solid-state switch coupled to the housing, wherein the housing covers the DC electronic solid-state switch, and the DC electronic solid-state switch has an on state and an off state, and the DC electronic solid-state switch comprises:

[0017] substrate;

[0018] An electrically insulating and heat-conductive layer disposed on the substrate;

[0019] a first electrically conductive trace disposed on the electrically insulating and thermally conductive layer, wherein the first electrically conductive trace forms a positive terminal;

[0020] a second electrically conductive trace disposed on the electrically insulating and thermally conductive layer, wherein the second electrically conductive trace forms a negative terminal;

[0021] a plurality of semiconductor dies, each semiconductor die disposed on the first conductive trace, wherein each of the plurality of semiconductor dies forms a MOSFET;

[0022] a first plurality of electrical bonds each electrically connected to a respective one of the plurality of semiconductor dies, wherein each of the first plurality of electrical bonds electrically interconnects the plurality of semiconductor dies and the second conductive trace;

[0023] a plurality of signal conductors, the plurality of signal conductors being disposed on the electrically insulating and thermally conductive layer;

[0024] a second plurality of electrical bonds electrically connecting the plurality of signal conductors to the plurality of semiconductor dies; and

[0025] Wherein, the DC electronic solid-state switch blocks a voltage between at least 650 volts and 1200 volts in a single direction in an off state, and the DC electronic solid-state switch continuously carries at least 400 amperes of direct current with a voltage drop of less than one volt in an on state.

[0026] 2. The switch assembly of claim 1, wherein the substrate has a thickness between two millimeters and three millimeters, and the plurality of semiconductor dies are electrically connected in parallel to one another.

[0027] 3. The switch assembly according to claim 2 further includes a solder layer, which is arranged between the substrate and the electrically insulating and heat-conductive layer to connect the substrate to the electrically insulating and heat-conductive layer, wherein the housing includes a polymer material, the electrically insulating and heat-conductive layer includes a ceramic material, and the substrate includes copper, the solder layer is directly coupled to the substrate, and each of the substrate, the electrically insulating and heat-conductive layer and the solder layer has a planar shape.

[0028] 4. The switch assembly of claim 3, wherein each of the first conductive trace and the second conductive trace is directly coupled to the electrically insulating thermally conductive layer, each of the first conductive trace and the second conductive trace is directly bonded to the electrically insulating thermally conductive layer, each of the plurality of signal conductors is directly coupled to the electrically insulating thermally conductive layer, and each of the plurality of signal conductors is directly bonded to the electrically insulating thermally conductive layer, and each of the plurality of signal conductors, the first conductive trace, and the second conductive trace comprises a metal material, and the metal material is selected from the group consisting of copper, aluminum, and alloys thereof.

[0029] 5. A switch assembly according to claim 4, wherein each of the plurality of semiconductor dies has a minimum area of ​​twenty square millimeters, each of the plurality of semiconductor dies comprises a semiconductor material selected from the group consisting of silicon, silicon carbide, gallium oxide, and gallium nitride, the plurality of semiconductor dies comprises four to sixteen semiconductor dies connected in parallel to carry a current of 400A, each of the first plurality of electrical bonds is at least one of a ribbon bond or a wire bond, and each of the second plurality of electrical bonds is a wire bond.

[0030] 6. The switch assembly of claim 5, wherein each of the first conductive trace and the second conductive trace is directly coupled to the electrically insulating thermally conductive layer, and the plurality of semiconductor dies comprises four to sixteen semiconductor dies, and each of the plurality of semiconductor dies has a specific on-resistance of less than 3.5 to 4.5 mΩ-cm 2 .

[0031] 7. The switch assembly according to claim 6, wherein the switch assembly has a maximum width of 55 to 65 mm, a maximum length of 65 mm, and a maximum height of 25 mm.

[0032] 8. A switch assembly according to Option 7, wherein the mass of the switch assembly is equal to or less than 250 grams.

[0033] 9. The switch assembly of Option 8 further comprises a plurality of thermistors coupled to the signal conductor.

[0034] 10. A switch assembly according to Option 9, wherein the isolation resistance of the switch assembly is greater than 50 megohms.

[0035] 11. The switch assembly of claim 10, wherein the DC electronic solid-state switch has a mass equal to or less than 250 grams and an on / off time of less than 10 microseconds.

[0036] 12. The switch assembly according to claim 11 further comprises a metal sheet, wherein the electrically insulating thermally conductive layer is directly bonded to the metal sheet, the metal sheet and the electrically insulating thermally conductive layer together form a directly bonded substrate, and the metal sheet comprises a metal selected from the group consisting of copper and aluminum.

[0037] 13. The switch assembly of claim 1, wherein the DC electronic solid-state switch is capable of continuously carrying a scalable current with a low on-resistance in an on-state, and the semiconductor die is capable of blocking direct current between at least 650V and 1200V.

[0038] 14. The switch assembly of claim 1, wherein a spacing between adjacent semiconductor dies in the plurality of semiconductor dies is greater than one millimeter and less than three millimeters.

[0039] 15. The switch assembly according to Option 1 further includes a heat sink directly coupled to the substrate, wherein the heat sink includes a heat sink and a plurality of pin-shaped heat sinks protruding from the heat sink, the substrate has a maximum thickness between two millimeters and three millimeters, and the maximum thickness of the heat sink is four millimeters.

[0040] 16. The switch assembly according to embodiment 15, further comprising a thermal interface material disposed between the heat sink and the substrate, wherein a maximum thickness of the thermal interface material is 0.1 mm, and a maximum thickness of the substrate is 2 mm.

[0041] 17. The switch assembly according to Option 16 further includes a metal sheet, wherein the electrically insulating thermally conductive layer is directly bonded to the metal sheet, the maximum thickness of the metal sheet is 0.3 mm, the maximum thickness of the electrically insulating thermally conductive layer is between 0.1 mm and 0.4 mm, the maximum thickness of each of the first conductive trace and the second conductive trace is between 0.3 mm and 0.8 mm, and the maximum thickness of each of the semiconductor dies is 0.2 mm.

[0042] 18. A direct current (DC) electronic solid-state switch comprising:

[0043] substrate;

[0044] An electrically insulating and heat-conductive layer disposed on the substrate;

[0045] a first electrically conductive trace disposed on the electrically insulating and thermally conductive layer, wherein the first electrically conductive trace forms a positive terminal;

[0046] a second electrically conductive trace disposed on the electrically insulating and thermally conductive layer, wherein the second electrically conductive trace forms a negative terminal;

[0047] a plurality of semiconductor dies, each semiconductor die disposed on the first conductive trace, wherein each semiconductor die of the plurality of semiconductor dies forms a MOSFET;

[0048] a first plurality of electrical bonds each electrically connected to a respective one of the plurality of semiconductor dies, wherein each of the first plurality of electrical bonds electrically interconnects the plurality of semiconductor dies and the second conductive trace;

[0049] a plurality of signal conductors disposed on the electrically insulating and thermally conductive layer; and

[0050] A second plurality of electrical bonds electrically connects the plurality of signal conductors to the plurality of semiconductor dies.

[0051] 19. A DC electronic solid-state switch according to claim 18, wherein the substrate has a thickness between two millimeters and three millimeters, and the plurality of semiconductor dies are electrically connected in parallel to each other.

[0052] 20. The DC electronic solid-state switch according to Option 19 further includes a solder layer arranged between the substrate and the electrically insulating thermally conductive layer to connect the substrate to the electrically insulating thermally conductive layer, wherein the electrically insulating thermally conductive layer includes a ceramic material and the substrate includes copper, the solder layer is directly coupled to the substrate, and each of the substrate, the electrically insulating thermally conductive layer and the solder layer has a planar shape.

[0053] The above features and advantages and other features and advantages of the present teachings are readily apparent from the following detailed description of some best modes and other embodiments for carrying out the present teachings when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 is a schematic perspective view of a switch assembly.

[0055] Figure 2 yes Figure 1 Schematic perspective exploded view of a switch assembly.

[0056] Figure 3 yes Figure 1 A schematic perspective view of a DC electronic solid-state switch of a switching assembly.

[0057] Figure 4 yes Figure 3 Schematic exploded view of a DC electronic solid-state switch shown.

[0058] Figure 5 yes Figure 3 A schematic elevation view of a semiconductor die of a DC electronic solid-state switch is shown.

[0059] Figure 6 yes Figure 3 Schematic electrical diagram of a DC electronic solid-state switch shown.

[0060] Figure 7 is a schematic top view of a DC electronic solid-state switch according to another embodiment of the present disclosure.

[0061] Figure 8 is a schematic side view of a DC electronic solid-state switch according to another embodiment of the present disclosure.

[0062] Fig. 9is a schematic side view of a DC electronic solid-state switch according to another embodiment of the present disclosure. DETAILED DESCRIPTION

[0063] The following detailed description is merely exemplary in nature and is not intended to limit the application and uses. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding description, summary, or the following detailed description.

[0064] Embodiments of the present disclosure may be described herein in terms of functional and / or logical block components and various processing steps. It should be understood that such block components may be implemented by multiple hardware, software, and / or firmware components configured to perform specified functions. For example, embodiments of the present disclosure may employ various integrated circuit components, such as memory elements, digital signal processing elements, logic elements, lookup tables, etc., which may perform various functions under the control of one or more microprocessors or other control devices. In addition, those skilled in the art will appreciate that embodiments of the present disclosure may be practiced in conjunction with multiple systems, and the systems described herein are merely exemplary embodiments of the present disclosure.

[0065] For the sake of brevity, technologies related to signal processing, data fusion, signal transmission, control and other functional aspects of the system (and the various operating components of the system) may not be described in detail herein. In addition, the connecting lines shown in the various figures included herein are intended to represent example functional relationships and / or physical couplings between the various elements. It should be noted that alternative or additional functional relationships or physical connections may exist in the embodiments of the present disclosure.

[0066] refer to Figure 1 , the switch assembly 100 includes a DC electronic solid-state switch 102 having an off state and an on state. Due to its configuration as described below, the DC electronic solid-state switch 102 is capable of blocking at least 900 volts in a single direction SD during the off state. Due to its configuration as described below, the DC electronic solid-state switch continuously carries at least 400 amperes of direct current during the on state, with a voltage drop of less than 1 volt. Due to its configuration as described below, the DC electronic solid-state switch 102 has a mass equal to or less than 250 grams, and the on / off time is less than 10 microseconds. Due to its configuration as described below, the switch assembly 100 has a maximum width MW of 55 to 65 mm, a maximum length ML of 65 mm, and a maximum height HH of 25 mm, thereby minimizing the size of the switch assembly 100. Due to the configuration described, the isolation resistance of the switch assembly is greater than 50 megohms (MΩ).

[0067] The switch assembly 100 includes a housing 104 covering the DC electronic solid-state switch 102. The housing 104 is also configured to hold and encapsulate the hardware of the DC electronic solid-state switch 102, and may be made in whole or in part of an electrically insulating and rigid material such as a rigid polymer material. Due to its configuration as described below, the mass of the switch assembly 100 does not exceed 250 grams.

[0068] refer to Figure 2-6 , the DC electronic solid-state switch 102 includes a substrate 106 having mounting holes 108 on opposite sides of the substrate 106. The substrate 106 has a maximum thickness BT between two millimeters and three millimeters to minimize the overall size of the DC electronic solid-state switch 102. In addition, the substrate 106 has a generally planar shape (and therefore a flat configuration) to minimize the overall size of the DC electronic solid-state switch 102. In addition, the substrate 106 can be made in whole or in part of a thermally conductive material, such as a metal or a metal matrix composite. For example, the substrate 106 can be made in whole or in part of copper, aluminum, molybdenum, or an alloy thereof, or a metal matrix composite material (such as AlSiC or copper foam), and can be mounted on a heat sink. The substrate 106 can preferably have a pin-shaped heat sink.

[0069] The DC electronic solid-state switch 102 includes an electrically insulating and thermally conductive layer 110 disposed on (although not directly on) the substrate 106. The electrically insulating and thermally conductive layer 110 may be entirely of or made of a ceramic material. Suitable ceramic materials for the electrically insulating and thermally conductive layer 110 include, but are not limited to, aluminum oxide (Al2O3), aluminum nitride (AlN), aluminum silicon carbide (AlSiC), silicon nitride (Si3N4), diamond, gallium oxide, and the like.

[0070] The DC electronic solid-state switch 102 includes a solder layer 112 disposed between the substrate 106 and the electrically insulating thermally conductive layer 110 to connect the substrate 106 to the electrically insulating thermally conductive layer 110. The term "solder" refers to a low melting point alloy used to connect metals with poor fusibility, especially a low melting point alloy based on lead and tin or (for higher temperatures) based on brass or silver. The solder layer 112 is directly disposed on the substrate 106 to facilitate and strengthen the connection between the solder layer 112 and the substrate 106. Each of the substrate 106, the electrically insulating thermally conductive layer 110, and the solder layer 112 has a planar shape to minimize the size of the DC electronic solid-state switch 102 coupled.

[0071] The DC electronic solid-state switch 102 also includes a metal sheet 114, which is directly coupled to the electrically insulating heat-conducting layer 110 to form a directly bonded substrate 1. The directly bonded substrate 115 has a thickness between 0.1 mm and 0.8 mm to minimize the size of the DC electronic solid-state switch 102. The metal sheet 114 can be directly bonded to the electrically insulating heat-conducting layer to form a directly bonded substrate. The metal sheet 114 can be made of copper in whole or in part, and thus form a directly bonded copper (DBC) substrate with the electrically insulating heat-conducting layer 110. The metal sheet 114 can be made of aluminum in whole or in part to form a directly bonded aluminum (DBA) substrate with the electrically insulating heat-conducting layer 110. The metal sheet 114 can be directly coupled to (and directly disposed on) the solder layer 112 to enhance the structural integrity of the DC electronic solid-state switch 102. In this way, the metal sheet 114 is arranged between the solder layer 112 and the electrically insulating heat-conducting layer 110 (e.g., a ceramic layer). In other words, the metal sheet 114 is sandwiched between the solder layer 112 and the electrically insulating and thermally conductive layer 110 .

[0072] The DC electronic solid-state switch 102 also includes a first conductive trace 116 disposed directly on the electrically insulating thermally conductive layer 110 to minimize the size occupied by the DC electronic solid-state switch 102. The first conductive trace 116 is disposed directly on (and directly bonded to) the electrically insulating thermally conductive layer 110 to enhance the structural integrity of the DC electronic solid-state switch 102. The first conductive trace 116 has a planar shape to minimize its size and forms a positive terminal. In addition, the first conductive trace 116 is made entirely or partially of a metal material, such as copper or aluminum.

[0073] The DC electronic solid-state switch 102 also includes a second conductive trace 118 disposed directly on the electrically insulating thermally conductive layer 110 to minimize the space occupied by the DC electronic solid-state switch 102. For example, the second conductive trace 118 is disposed directly on (and directly bonded to) the electrically insulating thermally conductive layer 110. The second conductive trace 118 has a planar shape to minimize its size and forms a negative terminal. In addition, the conductive trace 118 is made of a metal material, such as copper or aluminum.

[0074] The DC electronic solid-state switch 102 also includes a plurality of signal conductors 120 (e.g., a first signal conductor 120a and a second signal conductor 120b) disposed directly on the electrically insulating thermally conductive layer 110. The first conductive trace 116 is generally U-shaped and partially surrounds the signal conductor 120. In the present disclosure, the term "generally U-shaped" refers to a shape including two parallel legs directly connected to another leg perpendicular to the two parallel legs. The second conductive trace 118 is also generally U-shaped and partially surrounds the first conductive trace 116. The general U-shape of the first conductive trace 116 and the second conductive trace 118 helps to minimize the size of the DC electronic solid-state switch 102. The first signal conductor 120A and the second signal conductor 120B are made of a metal material such as copper or aluminum in whole or in part, and are directly bonded to the electrically insulating thermally conductive layer 110 (e.g., a ceramic layer). The first signal conductor 120a may be referred to as a source conductor (S), and the second signal conductor 120b may be referred to as a gate conductor. The control input transmitted through the signal conductor 120 draws near zero power (ie, less than 0.5 Watts) to keep the DC electronic solid-state switch 100 on or off.

[0075] The DC electronic solid-state switch 102 includes a plurality of semiconductor dies 122, each of which is disposed directly on the first conductive trace 116 to facilitate current flow. Although the depicted embodiment shows eight semiconductor dies 122, the DC electronic solid-state switch 102 includes four to sixteen semiconductor dies 122 (each having a rated voltage from 650 volts to 1200 volts) to be electrically connected in parallel with each other to carry 400A of current and enhance scalability. Each of the plurality of semiconductor dies forms a metal oxide semiconductor field effect transistor (MOSFET) 123 and includes a source terminal S, a gate terminal G, and a drain terminal D. Each semiconductor die 122 has a minimum area of ​​twenty square millimeters to share and carry 400A of current.

[0076] Each of the plurality of semiconductor dies 122 includes a semiconductor material such as silicon, silicon carbide, gallium oxide, and gallium nitride. The semiconductor dies 122 are arranged in a predetermined pattern on top of the direct bonding substrate 115 (eg, Figure 3 114 and the electrically insulating thermally conductive layer 110, the directly bonded substrate 115 also includes a first conductive trace 116, a second conductive trace 118, and a signal conductor 120. The bottom side of each semiconductor die 122 is directly coupled to the first conductive trace 116 (which has a predetermined shape). Each semiconductor die 122 has a resistance of less than 3.5 to 4.5 m-Ωcm. 2The arrangement of the semiconductor die 122 and the pattern of the direct bonding substrate 115 achieve equal current distribution and low parasitic inductance. The DC electronic solid-state switch 102 includes a plurality of damping resistors 121, each of which is electrically connected in series to the gate terminal of the corresponding MOSFET 123 to prevent or at least minimize power oscillations. A plurality of semiconductor die 122 are electrically connected in parallel to achieve a scalable rated current (e.g., multiples of 100A), and the switch assembly 100 includes an electrically insulating thermally conductive layer 110 (e.g., a ceramic layer) having a predetermined thermal stack height and pattern. For optimal thermal management, the spacing P between adjacent semiconductor die 122 is greater than 1 mm and less than 3 mm. The term "pitch" refers to the distance between the edge of one of the semiconductor die 122 and the nearest edge of an adjacent one of the semiconductor die 122.

[0077] The semiconductor die 122 may be capable of blocking 650V to 1200V (e.g., at least 1200V) DC, and the semiconductor die 122 may have different stack lengths. In this way, the DC electronic solid-state switch 102 is able to continuously carry a scalable current with a low on-resistance in the on state. The switch assembly 100 includes a plurality of semiconductor dies 122 electrically connected in parallel to each other so as to have scalability and different stack lengths in a minimum package size with an isolation resistance greater than 50M ohms. The electrically insulating thermally conductive layer 110 (e.g., a ceramic layer) may have a predetermined thermal stack height and pattern to provide the required thermal capacity.

[0078] The DC electronic solid-state switch 102 includes a first plurality of electrical bonds 124, each electrically connected to a corresponding one of the plurality of semiconductor dies 122. Specifically, each of the first plurality of electrical bonds 126 electrically connects the source terminal of the corresponding MOSFET 123 to the second conductive trace 118. Each of the first plurality of electrical bonds 126 electrically interconnects the plurality of semiconductor dies 122 and the second conductive trace 118. Each of the first plurality of electrical bonds 126 may be a high current aluminum or copper ribbon bond or foil bond to minimize parasitic inductance and resistance.

[0079] The DC electronic solid-state switch 102 also includes a second plurality of electrical bonds 128, each electrically connecting the plurality of signal conductors 120 to the plurality of semiconductor dies 122. Specifically, each of the second plurality of electrical bonds electrically connects the gate terminal G or source terminal of the corresponding MOSFET 123 to the first signal conductor 120a or the second signal conductor 120b. The second plurality of electrical bonds can be short, low current wire bonds to minimize parasitic inductance and resistance.

[0080] The DC electronic solid-state switch 102 may include a signal terminal 130 (e.g., a first signal terminal 130a and a second signal terminal 130b) electrically connected to the signal conductor 120. The first signal terminal 130a is directly coupled to the first signal conductor 120a and may be referred to as a gate terminal. The second signal terminal 130a is directly coupled to the second signal conductor 120a and may be referred to as a source terminal. The control input carried by the signal terminal 130 controls the on / off state of the DC electronic solid-state switch 102. The signal terminal 130 is electrically insulated from the substrate 106.

[0081] The DC electronic solid-state switch 102 may include a plurality of power terminals 132 (e.g., Figure 2 1. The first power terminal 132a is directly coupled to (and electrically connected to) the first conductive trace 116. The second power terminal 132b is directly coupled to (and electrically connected to) the second conductive trace 118. The power terminals 132 are electrically insulated from the substrate 106.

[0082] The DC electronic solid-state switch 102 may optionally include one or more thermistors 134 directly connected to the direct bonding substrate 115 ( Figure 7 ) to measure (with optimal accuracy) the temperature of the DC electronic solid-state switch 102. The thermistors 134 may be directly coupled to the additional signal conductors 140a, 140b to measure and monitor the temperature of the DC electronic solid-state switch 102. One thermistor 134 may be directly coupled to the first signal conductor pair 140a, and the other thermistor 134 may be directly coupled to the second signal conductor 140b. Alternatively, the thermistors 134 may be embedded as chips near the bare semiconductor die 122.

[0083] Reference Figure 7 , except for the features described below, the structure and function of the DC electronic solid-state switch 102a are substantially the same as the DC electronic solid-state switch 102 described above. A first conductive trace 116 is included in the DC electronic solid-state switch 102a, which is approximately U-shaped and partially surrounds the second conductive trace 118. The second conductive trace 118 is T-shaped. The signal conductor 120 is approximately U-shaped and partially surrounds the first conductive trace 116 and the second conductive trace 118. This configuration facilitates manufacturing and improves reliability. The signal conductor 120a has a plurality of top-side wire-bonded chip resistors 121, which are electrically attached to the signal trace 120a on the lower side. The upper side of the chip resistor 121 is wire-bonded to the gate terminal of the closest semiconductor die 122. The use of the top-side wire-bonded chip resistor 121 saves space, minimizes parasitic inductance in the switch module, and attenuates high-frequency oscillations during switching.

[0084] refer to Figure 8 , except for the features described below, the structure and function of the DC electronic solid-state switch 102b are substantially the same as the DC electronic solid-state switch 102 described above. The DC electronic solid-state switch 102b includes a heat sink 136, which includes a heat sink plate 138 and a plurality of pin-shaped heat sinks 140 protruding directly from the bottom side of the heat sink plate. The pin-shaped heat sink 140 may be made of aluminum in whole or in part. The maximum total thickness MTH of the heat sink plate 138 is between four millimeters and ten millimeters to enhance the thermal characteristics of the DC electronic solid-state switch 102b while minimizing its size.

[0085] The DC electronic solid-state switch 102b also includes a thermal interface material 142 directly disposed on the upper surface of the heat sink 138 (and in direct contact therewith) to maximize heat transfer between the heat sink 138 and the thermal interface material 142. The term "thermal interface material" refers to a material inserted between two components to enhance the thermal coupling between them. Suitable thermal interface materials include, but are not limited to, thermal grease, thermal adhesives, thermal gap fillers, thermal pads, thermal tapes, and phase change materials, direct sintering or brazing joints, etc. The maximum thickness MH of the thermal interface material 142 is less than 0.1 mm to enhance the thermal characteristics of the DC electronic solid-state switch 102b while minimizing its size.

[0086] The substrate 106 of the DC electronic solid-state switch 102b is directly disposed on (and in direct contact with) the thermal interface material 142 to maximize heat transfer between the substrate 106 and the thermal interface material 142. As described above, the substrate 106 may be made in whole or in part of a metal material, such as copper, aluminum, and / or alloys thereof, and metal matrix composite materials. The maximum thickness BH of the substrate 106 is two millimeters to enhance the thermal characteristics of the DC electronic solid-state switch 102b while minimizing its size.

[0087] The solder layer 112 of the DC electronic solid-state switch 102b is disposed directly on (and in direct contact with) the substrate 106 to enhance the structural integrity of the DC electronic solid-state switch 102b. The maximum thickness SH of the solder layer 112 is at most 0.1 mm to enhance the thermal characteristics of the DC electronic solid-state switch 102b while minimizing its size.

[0088] The metal sheet 114 of the DC electronic solid-state switch 102b is directly disposed on (and in direct contact with) the solder layer 112 to enhance the structural integrity of the DC electronic solid-state switch 102b. The maximum thickness CH of the metal sheet 114 is at most 0.3 mm to enhance the thermal characteristics of the DC electronic solid-state switch 102b while minimizing its size. As described above, the metal sheet 114 can be made of copper, aluminum and / or alloys thereof in whole or in part.

[0089] The electrically insulating thermally conductive layer 110 (e.g., a ceramic layer) of the DC electronic solid-state switch 102b is directly disposed on (and in direct contact with) the metal sheet 114 to enhance the structural integrity of the DC electronic solid-state switch 102b. The electrically insulating thermally conductive layer 110 has a maximum thickness RH of 0.0.1 to 0.4 mm to enhance the thermal characteristics of the DC electronic solid-state switch 102b while minimizing its size.

[0090] The first conductive trace 116 and the second conductive trace 118 of the DC electronic solid-state switch 102b are directly disposed on (and in direct contact with) the electrically insulating thermally conductive layer 110 to enhance the structural integrity of the DC electronic solid-state switch 102b. The maximum thickness FSH of the first conductive trace 116 and the second conductive trace 118 is between 0.3 mm and 0.8 mm to enhance the electrical and thermal characteristics of the DC electronic solid-state switch 102b while minimizing its size.

[0091] Another solder layer 112 of the DC electronic solid-state switch 102b is disposed directly on (and in direct contact with) the first conductive trace 116 and the second conductive trace 118 to enhance the structural integrity of the DC electronic solid-state switch 102b. The maximum thickness of the solder layer 112 is at most 0.1 mm to enhance the thermal characteristics of the DC electronic solid-state switch 102b while minimizing its size.

[0092] The semiconductor die 122 of the DC electronic solid-state switch 102b is disposed directly on (and in direct contact with) the solder layer 112 to enhance the structural integrity of the DC electronic solid-state switch 102b. The maximum thickness SCH of each semiconductor die 122 is 0.2 mm to enhance the thermal characteristics of the DC electronic solid-state switch 102b while minimizing its size.

[0093] Due to the size, spacing and materials of the components of the DC electronic solid-state switch 102b described above, the total thermal stack resistance Rth (without the heat sink 136) is less than one degree Celsius per watt. The thermal stack and layout of the DC electronic solid-state switch 102b minimizes current imbalance and reduces the temperature rise through the thermal conduction path, or due to thermal crosstalk between the semiconductor die 122, assuming a worst-case cooling plate at 85 degrees Celsius. For minimum temperature rise, the thickness of the different components (as described above) should be used to minimize the temperature rise in the DC electronic solid-state switch 102b. Moreover, the die-to-die spacing, the die-to-edge spacing, and the die-to-terminal spacing affect the temperature rise in the DC electronic solid-state switch 102b. In an exemplary case, the temperature difference from the semiconductor die 122 to the heat sink 136 can preferably be less than 50 degrees Celsius. The power dissipated by each semiconductor die 122 can preferably be less than 50 watts. The drain-source resistance R of the exemplary semiconductor die 122 DS(on)20 milliohms at its highest temperature. The feasible current carried by each such semiconductor die 122 is 50 amps. For a 400A rating, eight such semiconductor dies 122 should be used and electrically connected in parallel.

[0094] refer to Fig. 9 , except for the features described below, the structure and function of the DC electronic solid-state switch 102c are substantially the same as the DC electronic solid-state switch 102 described above. In the DC electronic solid-state switch 102c, each signal conductor 120 (e.g., the first signal conductor 120a and the second signal conductor 120b) includes a pad 144 for soldering the pins of the external gate (G) and source (S) terminals of the DC electronic solid-state switch 102.

[0095] The detailed description and the accompanying drawings or pictures support and describe the present teaching, but the scope of the present teaching is limited only by the claims. Although some best modes and other embodiments for carrying out the present teaching have been described in detail, there are various alternative designs and embodiments for practicing the present teaching defined in the appended claims.

Claims

1. A switch assembly, comprising: case; A direct current (DC) electronic solid-state switch coupled to the housing, wherein the housing covers the DC electronic solid-state switch, and the DC electronic solid-state switch has an on state and an off state, and the DC electronic solid-state switch comprises: substrate; An electrically insulating and heat-conductive layer disposed on the substrate; a first electrically conductive trace disposed on the electrically insulating and thermally conductive layer, wherein the first electrically conductive trace forms a positive terminal; a second electrically conductive trace disposed on the electrically insulating and thermally conductive layer, wherein the second electrically conductive trace forms a negative terminal; a plurality of semiconductor dies, each semiconductor die disposed on the first conductive trace, wherein each of the plurality of semiconductor dies forms a MOSFET; a first plurality of electrical bonds each electrically connected to a respective one of the plurality of semiconductor dies, wherein each of the first plurality of electrical bonds electrically interconnects the plurality of semiconductor dies and the second conductive trace; a plurality of signal conductors, the plurality of signal conductors being disposed on the electrically insulating and thermally conductive layer; a second plurality of electrical bonds electrically connecting the plurality of signal conductors to the plurality of semiconductor dies; and Wherein the DC electronic solid-state switch blocks voltages between 650 volts and 1200 volts in a single direction in an off state, and the DC electronic solid-state switch continuously carries at least 400 amperes of direct current with a voltage drop of less than one volt in an on state.

2. The switch assembly according to claim 1, wherein: The substrate has a thickness between two and three millimeters, and the plurality of semiconductor dies are electrically connected in parallel to one another.

3. The switch assembly according to claim 2, further comprising a solder layer, the solder layer being disposed between the substrate and the electrically insulating and thermally conductive layer to connect the substrate to the electrically insulating and thermally conductive layer, wherein The housing includes a polymer material, the electrically insulating and thermally conductive layer includes a ceramic material, and the substrate includes copper, the solder layer is directly coupled to the substrate, and each of the substrate, the electrically insulating and thermally conductive layer, and the solder layer has a planar shape.

4. The switch assembly according to claim 3, wherein: Each of the first conductive trace and the second conductive trace is directly coupled to the electrically insulating thermally conductive layer, each of the first conductive trace and the second conductive trace is directly bonded to the electrically insulating thermally conductive layer, each of the plurality of signal conductors is directly coupled to the electrically insulating thermally conductive layer, and each of the plurality of signal conductors is directly bonded to the electrically insulating thermally conductive layer, and each of the plurality of signal conductors, the first conductive trace, and the second conductive trace comprises a metal material selected from the group consisting of copper, aluminum, and alloys thereof.

5. The switch assembly according to claim 4, wherein: Each of the plurality of semiconductor dies has a minimum area of ​​twenty square millimeters, each of the plurality of semiconductor dies comprises a semiconductor material selected from the group consisting of silicon, silicon carbide, gallium oxide, and gallium nitride, the plurality of semiconductor dies comprises four to sixteen semiconductor dies connected in parallel to carry a current of 400A, each of the first plurality of electrical bonds is at least one of a ribbon bond or a wire bond, and each of the second plurality of electrical bonds is a wire bond.

6. The switch assembly according to claim 5, wherein: Each of the first conductive trace and the second conductive trace is directly coupled to the electrically insulating thermally conductive layer, and the plurality of semiconductor dies includes four to sixteen semiconductor dies, and each of the plurality of semiconductor dies has a specific on-resistance of less than 3.5 mΩ-cm 2 .

7. The switch assembly according to claim 6, wherein: The switch assembly has a maximum width of 55 mm, a maximum length of 65 mm and a maximum height of 25 mm.

8. The switch assembly according to claim 7, wherein: The mass of the switch assembly is equal to or less than 250 grams.

9. The switch assembly of claim 8, further comprising a plurality of thermistors coupled to the signal conductors.

10. The switch assembly according to claim 9, wherein: The isolation resistance of the switch assembly is greater than 50 megohms.

11. The switch assembly according to claim 10, wherein: The DC electronic solid-state switch has a mass equal to or less than 250 grams and an on / off time of less than 10 microseconds.

12. The switch assembly of claim 11, further comprising a metal sheet, wherein the electrically insulating thermally conductive layer is directly bonded to the metal sheet, the metal sheet and the electrically insulating thermally conductive layer together form a directly bonded substrate, and the metal sheet comprises a metal selected from the group consisting of copper and aluminum.

13. The switch assembly according to claim 1, wherein: The DC electronic solid-state switch is capable of continuously carrying a scalable current with a low on-resistance in an on-state, and the semiconductor die is capable of blocking direct current between 650V and 1200V.

14. The switch assembly according to claim 1, wherein: A spacing between adjacent semiconductor dies in the plurality of semiconductor dies is greater than one millimeter and less than three millimeters.

15. The switch assembly of claim 1 further comprising a heat sink directly coupled to the substrate, wherein: The heat sink includes a heat dissipation plate and a plurality of pin-shaped heat dissipation fins protruding from the heat dissipation plate, the base plate has a maximum thickness of two millimeters, and the maximum thickness of the heat dissipation plate is four millimeters. 16 . The switch assembly of claim 15 , further comprising a thermal interface material disposed between the heat sink and the substrate, wherein a maximum thickness of the thermal interface material is 0.1 mm, and a maximum thickness of the substrate is 2 mm.

17. The switch assembly of claim 16, further comprising a metal sheet, wherein the electrically insulating thermally conductive layer is directly bonded to the metal sheet, the maximum thickness of the metal sheet is 0.3 mm, the maximum thickness of the electrically insulating thermally conductive layer is 0.1 mm, the maximum thickness of each of the first conductive trace and the second conductive trace is 0.3 mm, and the maximum thickness of each of the semiconductor dies is 0.2 mm.

18. The switch assembly according to claim 5, wherein: Each of the first conductive trace and the second conductive trace is directly coupled to the electrically insulating thermally conductive layer, and the plurality of semiconductor dies includes four to sixteen semiconductor dies, and each of the plurality of semiconductor dies has a specific on-resistance of less than 4.5 mΩ-cm 2 .

19. The switch assembly according to claim 6, wherein: The switch assembly has a maximum width of 65 mm, a maximum length of 65 mm and a maximum height of 25 mm.

20. The switch assembly of claim 1, further comprising a heat sink directly coupled to the substrate, wherein: The heat sink includes a heat dissipation plate and a plurality of pin-shaped heat dissipation fins protruding from the heat dissipation plate, the base plate has a maximum thickness of three millimeters, and the heat dissipation plate has a maximum thickness of four millimeters.

21. The switch assembly of claim 16, further comprising a metal sheet, wherein the electrically insulating thermally conductive layer is directly bonded to the metal sheet, the maximum thickness of the metal sheet is 0.3 mm, the maximum thickness of the electrically insulating thermally conductive layer is 0.4 mm, the maximum thickness of each of the first conductive trace and the second conductive trace is 0.8 mm, and the maximum thickness of each of the semiconductor dies is 0.2 mm.

22. A DC electronic solid-state switch, comprising: substrate; An electrically insulating and heat-conductive layer disposed on the substrate; a first electrically conductive trace disposed on the electrically insulating and thermally conductive layer, wherein the first electrically conductive trace forms a positive terminal; a second electrically conductive trace disposed on the electrically insulating and thermally conductive layer, wherein the second electrically conductive trace forms a negative terminal; a plurality of semiconductor dies, each semiconductor die disposed on the first conductive trace, wherein each semiconductor die of the plurality of semiconductor dies forms a MOSFET; a first plurality of electrical bonds each electrically connected to a respective one of the plurality of semiconductor dies, wherein each of the first plurality of electrical bonds electrically interconnects the plurality of semiconductor dies and the second conductive trace; a plurality of signal conductors disposed on the electrically insulating and thermally conductive layer; and A second plurality of electrical bonds electrically connects the plurality of signal conductors to the plurality of semiconductor dies.

23. A DC electronic solid state switch according to claim 22, wherein: The substrate has a thickness between two and three millimeters, and the plurality of semiconductor dies are electrically connected in parallel to one another.

24. The DC electronic solid-state switch of claim 23, further comprising a solder layer disposed between the substrate and the electrically insulating thermally conductive layer to connect the substrate to the electrically insulating thermally conductive layer, wherein The electrically insulating and thermally conductive layer includes a ceramic material, and the substrate includes copper, the solder layer is directly coupled to the substrate, and each of the substrate, the electrically insulating and thermally conductive layer, and the solder layer has a planar shape.

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