Single-switch power module

Abstract

The invention relates to a single-switch power module (100) comprising: a substrate (128), wherein the substrate (128) has a metallisation (146), wherein one or more semiconductor components (106) are arranged on the metallisation (146), and a leadframe (108) having a first part (110) and a second part (112), wherein the first part (110) has a gate (118), a source (120) and a power source (122) and the second part (112) has a power drain (124), wherein the one or more semiconductor components (106) are positioned parallel to the longitudinal direction (104) on the substrate (128), wherein a first connection for electrically contacting the power source (122) to a semiconductor component source (136) is implemented via a design (140) of the power source (122), with at least one first recess (144.1), a second recess (144.2) and a step (206) produced by stamping, wherein a second connection for electrically contacting the gate (118) to one or more semiconductor element gates (134) is implemented by bond connections (142.1, 142.2, 142.3) with the incorporation of a bond wire (132) and a port (116).

Description

[0001] Description

[0002] title

[0003] Technical field

[0004] The invention relates to a single-switch power module comprising a substrate with a semiconductor device array and a connection frame with a first part and a second part. Furthermore, the invention relates to a use of the single-switch power module.

[0005] State of the art

[0006] According to the state of the art, single-switch power modules such as STPAK from STMicroelectronic and Wolfspeed are known. These are used, for example, in Tesla's drive inverters. Such modules are characterized by one or more, typically two, semiconductor devices (SiC MOSFETs or Si IGBTs with a diode) mounted on an insulated AM B substrate. The assembly features a copper connection frame that serves as both a high-current and signal contact. One side is typically connected to the AM B substrate, the other to the front of the semiconductor device. The control connections of the semiconductor device are typically wire-bonded to a potential island on the AM B substrate and from there, also by wire bonding, to the connection frame. The entire assembly is encapsulated using the transfer molding process. The lower metallization of the AM B substrate remains exposed.This allows the modules to be sintered or soldered onto a heat sink later. A significant portion of the front-side metallization of the AMB is, according to current technology, "used up" for wiring the control connections of the semiconductor components. As a result, this metallization is no longer available for thermal expansion. In the case of the STPAK, this "area consumption" is 15%, and in the case of the Wolfspeed package, it is approximately 30%. Furthermore, the semiconductor components within the module are arranged orthogonally to the longitudinal direction.

[0007] Connecting the terminal frame to the upper potential of the semiconductor device requires that the central part of the semiconductor device, where the so-called gate runner is located, is not connected. Therefore, the terminal frame is embossed accordingly, creating a raised area in the region of the gate runner. With regard to the semiconductor device area, this means that the semiconductor devices must primarily grow in the transverse direction, i.e., orthogonally to the longitudinal direction, because otherwise the gate runner would be covered or the semiconductor device would be positioned too close to the edge of the metallization, resulting in unfavorable thermal behavior.

[0008] Disclosure of the invention

[0009] Single-switch power module comprising: a substrate with a metallization on which one or more semiconductor devices are arranged and a connection frame with a first part and a second part, wherein the first part has a gate, a source and a power source and the second part has a power drain.

[0010] The one or more semiconductor devices are placed parallel to the longitudinal direction on the substrate, wherein a first connection for electrical contacting the power source to a semiconductor device source is made via a design of the power source, wherein the design has at least a first recess and a second recess and a step embossing, wherein a second connection for electrical contacting the gate with one or more semiconductor device gates is made by one or more bond connections by inserting a bond wire and a terminal.

[0011] A single-switch power module is an electronic component for controlling or regulating power, such as current or voltage, in an electronic circuit. The connection frame according to the invention comprises a first part and a second part, both parts being attached to the single-switch power module, which contains, for example, semiconductor components. The connection frame, also called a leadframe, is formed by one or more structured printed circuit boards, such as gate, source, power source, and drain, made of a conductive material, such as copper. These form part of a single switching module and provide an interface for an electrical connection between the module and the corresponding connection frame or other components in an electronic system.A power source, as defined in the invention, is a terminal of the first part of the terminal frame, which is exclusively dedicated to the load current (AC and / or DC) flowing into a connected sink or supplied by a connected source. A gate is an element of the first part of the terminal frame in an electronic circuit, used to control current flow. For example, a specific electronic state can be activated or deactivated by applying an external voltage to the gate. The gate also acts as a control point for the flow of information or energy within a circuit, such as a single-switch power module. The source is the starting point for the first part of the electrical current flow and contributes to the energy flow within a circuit. Through an electrical connection to the source, the elements of the circuit are supplied with charge carriers.

[0012] A semiconductor device is an electronic component whose electrical conductivity can change depending on certain external influences such as voltage, current, or light. Semiconductor devices are typically made from materials such as silicon or germanium, which can both conduct and insulate electricity under certain conditions. A MOSFET (Metal Oxide Semiconductor Field Effect Transistor) is an example of a semiconductor device used in single-switch power modules. These transistors are made from a semiconductor material such as silicon and have at least three terminals: a source, a drain, and a gate.The semiconductor gate is the crucial component of the MOSFET, generating an electrical potential that controls the current flow in the channel between the semiconductor source and drain. The voltage across the semiconductor gate controls the conductivity of the channel, making MOSFETs highly efficient switches. The semiconductor source is the terminal through which the electrical current enters the channel, while the semiconductor drain is the output terminal through which the current leaves the channel. A gate runner, extending lengthwise along the semiconductor source, is a special structure used in some MOSFET designs to improve performance and efficiency. This distributes the electric field more evenly across the channel, reducing hot spots and optimizing switching speed.

[0013] In an advantageous further development of the single-switch power module proposed according to the invention, the first recess and the second recess are dimensioned such that a bonding tool for producing the first bond connection and the second bond connection can be placed within the first and the second recess.

[0014] In order to connect the control terminal of the semiconductor device gate to the terminal frame via the first and second bond connections, the first and second recesses are provided in the terminal frame in the area of ​​the power source terminal in the solution according to the invention. Within these recesses, after the terminal frame, in particular the first part of the terminal frame, has been placed, a bond wire can be guided from the gate of the semiconductor device to a terminal on the substrate. From there, the gate is connected to the external control electrodes, namely the terminal of the terminal frame.

[0015] In an advantageous further development of the single-switch power module proposed according to the invention, the connection for electrical contacting of the power source to the one or more semiconductor components is made by a solder connection.

[0016] In an advantageous embodiment of the single-switch power module proposed according to the invention, one or more semiconductor devices are positioned on the metallization such that the semiconductor device gate is oriented against the longitudinal direction. In a further advantageous embodiment of the single-switch power module proposed according to the invention, a second connection comprises a first bond connection, a second bond connection, and a third bond connection.

[0017] In a further advantageous embodiment of the single-switch power module proposed according to the invention, the first and second bond connections have an electrical contact between the semiconductor component gates and the terminal, wherein the first and second bond connections are spaced apart next to each other.

[0018] In an advantageous further development of the single-switch power module proposed according to the invention, the third bond connection has an electrical contact between the gate and the terminal, wherein the second and the third bond connection are spaced apart next to each other.

[0019] In an advantageous further development of the single-switch power module proposed according to the invention, the embodiment has a fork-shaped design comprising at least two or more fingers.

[0020] In a further advantageous embodiment of the single-switch power module proposed according to the invention, the fork-shaped design has a first fork, a second fork and a third fork, wherein the first and third forks each have one finger, and the second fork has a Y-fork shape with two fingers.

[0021] The first and / or second part of the terminal frame may also feature step embossing, a process in which the terminal frame is selectively shaped in certain areas to create structural features, such as a raised area. Step embossing is used to make the terminal frame more robust and reliable, or to facilitate contact with the semiconductor device.

[0022] A stepped embossing is created, for example, by pressing or stamping the connecting frame to form raised areas or steps. These steps can have different shapes and sizes depending on the requirements of the specific application. The steps serve, for example, to increase the mechanical stability of the component by providing additional support, or to improve heat dissipation by increasing the surface area.

[0023] Furthermore, the invention relates to the use of the single-switch power module in drive converters to enable efficient and reliable power control and conversion in electrical drive systems.

[0024] Advantages of the invention

[0025] In the solution according to the invention, the semiconductor components are advantageously arranged with their longest edge parallel to the longitudinal direction, which is thermally advantageous because this provides a large area around the semiconductor components, allowing the power loss to be distributed laterally and thus efficiently dissipated downwards into the heat sink.

[0026] Another advantage of this arrangement of semiconductor devices is that, in the bond wire region, the gate is routed parallel to the power source and source, resulting in a minimal conductor loop. The resulting mutual inductance leads to minimal parasitic inductance at the control terminal, thus optimizing the gate penetration of the semiconductor device. When switching the opposite topological gate switch in a half-bridge, the capacitive displacement current via the Miller capacitance can briefly and unintentionally charge the gate, thereby parasitically switching on the transistor. A low-inductance control loop allows the semiconductor devices to be driven more quickly, thus reducing switching losses.

[0027] Furthermore, the orthogonal alignment of the main current path and the gate current path on the substrate advantageously suppresses couplings, namely drain-to-gate. The solution according to the invention also proposes an advantageous fork-shaped configuration, designed to mechanically relieve the gate runner on the semiconductor device. Simultaneously, the advantageous Y-shaped fork configuration creates a low-inductance current path in the area between the semiconductor devices, through which compensating currents can flow, thereby suppressing, for example, vibrations and oscillations of the load current between the semiconductor devices.

[0028] The semiconductor components can be advantageously scaled in both length and width by connecting them using a "fork shape".

[0029] The recess formed by the fork also contributes to a better connection between the connecting frame and the mold body, as a positive fit is achieved by filling the recesses with the injection molding tool (transfer mold).

[0030] The recess also reduces the volume of the copper connection frame, thereby minimizing thermal expansion mismatch (due to differing thermal conductivity coefficients) between the mold body and the connection frame. The result is a less rigid connection, allowing for lower mechanical stress, particularly at the interface with the semiconductor device.

[0031] Brief description of the drawings

[0032] Embodiments of the invention are explained in more detail with reference to the drawings and the following description.

[0033] They show:

[0034] Figure 1 shows a schematic representation of a single-switch power module with one embodiment of the connection frame and

[0035] Figure 2 is a schematic representation of how a first bond connection is made using a bonding tool. Embodiments of the invention

[0036] In the following description of embodiments of the invention, identical or similar elements are designated by the same reference numerals, and repeated descriptions of these elements are omitted in individual cases. The figures represent the subject matter of the invention only schematically.

[0037] Figure 1 shows a schematic representation of a single-switch power module 100 with a connection frame 108. Figure 1 also shows the single-switch power module 100, the connection frame 108 with a first part 110 and a second part 112, and two semiconductor components 106.

[0038] Figure 1 further illustrates that the first part 110 of the connection frame 108 has a gate 118, a source 120, and a power source 122, and the second part 112 has a power drain 124. Furthermore, the single-switch line module 100 has a substrate 128 with a metallization 146, two semiconductor devices 106, and a terminal 116 positioned next to the metallization 146. The substrate 128 can, for example, be made of ceramic 128.1.

[0039] The semiconductor device 106 according to Figure 1 has a semiconductor device gate 134 and a semiconductor device source 136. The multiple semiconductor devices 106 are arranged parallel to the longitudinal direction 104. Furthermore, it can be seen that the semiconductor device source 136 is divided into two parts such that a gate runner 126 is located between the two divided sections of the semiconductor device source 136.

[0040] Figure 1 further shows that the power source 122 is connected to the source 120 and, by means of four fingers 138, to the semiconductor component source 136 of the semiconductor components 106. It can also be seen that the power source 122 has an embodiment 140 with the source 120. The embodiment 140 is formed from a fork-shaped structure 140.1 with a first fork 152.1, a second fork 152.2, the second fork having a Y-shaped fork 141, and a third fork 153.3, which has a first recess 144.1 and a second recess 144.2. The first and third forks 152.1 and 152.3 each have one finger 138, and the second fork 152.2 has two fingers 138. The first and second recesses 144.1, 144.2 have a recess width of 148 and a recess length of 150, which define the first and second recesses 144.1, 144.2 in the connecting frame 108, namely the recess width 148 and the recess length 150, are designed such that they are suitable for receiving a bonding tool 200. The recess width 148 of the first and second recesses 144.1, 144.2, the recess length 150 of the first and second recesses 144.1, 144.2, and optionally a step height in the embossed connecting frame 108 are important in this respect. For functional reasons, the first and second recesses 144.1, 144.2 are preferably designed to be so small and narrow that the dimensions, namely recess width 148 and recess length 150, are predetermined by the bonding tool 200 for the bonding process. The step height of the connection frame 108 is preferably designed to be as flat as possible, with the result that typical bonding tools 200 become larger with increasing distance from the bonding point, i.e., they increase in width. This is illustrated in Figure 2.

[0041] Figure 1 further shows a connection of the two semiconductor device gates 134 to the gate 118 of the first part 110 of the connection frame 108 via a first bond connection 142.1, a second bond connection 142.2 and a third bond connection 142.3 with the insertion of a bond wire 132 and the connection 116 on the substrate 128.

[0042] Figure 2 shows a schematic representation of the production of a first bond connection by a bonding tool 200 of a single-switch line module 100 with a terminal frame 108. Figure 2 further shows the single-switch line module 100, the terminal frame 108 with two semiconductor devices 106. Figure 2 also shows the first part 110 of the terminal frame 108, the gate 118, the power source 122, and the power drain 124. The single-switch line module 100 also has a substrate 128 with a metallization 146, two semiconductor devices 106, and, next to the metallization 146, the terminal 116. The substrate 128 can, for example, be made of ceramic 128.1.

[0043] The semiconductor device 106 according to Figure 2 has a semiconductor device gate 134 and a semiconductor device source 136. The two semiconductor devices 106 are arranged parallel to the longitudinal direction 104. Furthermore, it can be seen that the semiconductor device source 136 is divided into two parts, such that a gate runner 126 is located between the two divided sections of the semiconductor device source 136.

[0044] Furthermore, Figure 2 shows that the power source 122 is connected to the source 120 and, by means of four fingers 138, to the semiconductor component source 136 of the semiconductor component 106. It can also be seen that the power source 122 has an embodiment 140 with the source 120. Embodiment 140 is formed from a fork-shaped embodiment 140.1 with a first fork 152.1, a second fork 152.2, the second fork having a Y-shaped fork 141, and a third fork 152.3, which has a first recess 144.1 and a second recess 144.2. The first and third forks 152.1 and 152.3 each have one finger 138, and the second fork 152.2 has two fingers 138. Furthermore, Figure 2 shows that a bonding tool 200 has been inserted into the first recess 144.1.The bonding tool 200 has an asymmetrical profile, starting from a narrow end with a first width 202 and gradually widening to a wider end with a second width 204 in the Z-direction 208. Figure 2 also shows that the first and second recesses 144.1, 144.2 each have a recess width 148 and a recess length 150, designed such that the bonding tool 200 can be inserted into it with a bonding wire 132 to create the first and second bond connections 142.1, 142.2. Figure 2 also shows that the power source 122 has a stepped embossing 206.

[0045] The invention is not limited to the embodiments described here and the aspects highlighted therein. Rather, within the scope specified by the claims, a multitude of modifications are possible that fall within the bounds of what is considered skilled in the art.

Claims

Claims 1. Single-switch power module (100) comprising: a substrate (128), wherein the substrate (128) has a metallization (146), wherein one or more semiconductor devices (106) are arranged on the metallization (146), and a connection frame (108), wherein the connection frame (108) has a first part (110) and a second part (112), the first part (110) having a gate (118), a source (120), and a power source (122), and the second part (112) having a power drain (124), wherein the one or more semiconductor devices (106) are placed parallel to the longitudinal direction (104) on the substrate (128), wherein a first connection for electrically contacting the power source (122) to a semiconductor device source (136) is made via a feature (140) of the power source (122), the feature (140) having at least a first recess (144.1) and a second recess (144.2) and has a step embossing (206), wherein a second connection for electrical contacting of the gate (118) with one or more semiconductor device gates (134) is made by one or more bond connections (142.1 , 142.2, 142.3) by introducing a bond wire (132) and a connection (116).

2. Single-switch power module (100) according to claim 1, wherein the first recess (144.1) and the second recess (144.2) are dimensioned such that a bonding tool (200) for producing the first bond connection (142.1) and the second bond connection (142.2) can be placed within the first and second recesses (144.1, 144.2).

3. Single switch power module (100) according to claim 1 or 2, wherein the connection for electrical contacting the power source (122) on the one or more semiconductor devices (106) by means of a solder connection.

4. Single-switch power module (100) according to one of the preceding claims, wherein the one or more semiconductor devices (106) is / are positioned on the metallization (146) such that the semiconductor device gate (134) is aligned opposite to the longitudinal direction (104).

5. Single-switch power module (100) according to one of the preceding claims, wherein a second connection comprises a first bond connection (142.1), a second bond connection (142.2) and a third bond connection (142.3).

6. Single-switch power module (100) according to one of the preceding claims, wherein the first and second bond connections (142.1 , 142.2) have an electrical contact between the semiconductor device gates (134) and the terminal (116), wherein the first and second bond connections (142.1 , 142.2) are spaced apart next to each other.

7. Single-switch power module (100) according to one of the preceding claims, wherein the third bond connection (142.3) has an electrical contact between the gate (118) and the terminal (116), wherein the second and the third bond connection (142.2, 142.3) are spaced apart next to each other.

8. Single switch power module (100) according to one of the preceding claims, wherein the embodiment has a fork-shaped design (140.1) comprising at least two or more fingers (138).

9. Single-switch power module (100) according to claim 7, wherein the fork-shaped design (140.1) has a first fork (152.1), a second fork (152.2) and a third fork (152.3), wherein the first and third forks (152.1, 152.3) each have a finger (138), wherein the second fork (152.2) has a Y-fork shape (141) with two fingers (138).

10. Use of the single-switch power module (100) according to one of the preceding claims in drive converters.

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