Cooling element for a semiconductor device, manufacturing process for cooling element and method for operating a semiconductor device

Abstract

The approach presented here comprises a cooling element (100) for a semiconductor device (120), wherein the cooling element has a cooling channel (125) for guiding a cooling fluid, and a heat sink (110) with at least one cooling structure (115), wherein the cooling structure (115) is arranged at or forms such an end of the heat sink (110) and extends into an interior of the cooling channel (125), and wherein the heat sink (110) has a heat absorption area (135) for heat from the semiconductor device (120), which is arranged laterally offset to the cooling structure (115) in the cooling channel (125).

Description

[0001] The present invention relates to a cooling element for a semiconductor device, a manufacturing method for a cooling element and a method for operating a semiconductor device.

[0002] Cooling elements can be shaped to cool electrical components. However, this can result in insufficient heat dissipation, meaning that a semiconductor component is not adequately cooled.

[0003] Against this background, the present invention provides an improved cooling element for a semiconductor device, an improved manufacturing process for a cooling element, and an improved method for operating a semiconductor device, according to the main claims. Advantageous embodiments are described in the dependent claims and the following description.

[0004] Cooling of a semiconductor component in a cooling channel can take place through one or more cooling structures.

[0005] The invention comprises a cooling element for a semiconductor device, which includes a cooling channel for guiding a cooling fluid; and a heat sink with at least one cooling structure, wherein the cooling structure is arranged at or forms such an end of the heat sink and extends into an interior of the cooling channel, and wherein the heat sink has a heat absorption area for heat from the semiconductor device, which is arranged laterally offset to the cooling structure in the cooling channel.

[0006] A cooling element can be understood as a device which, according to one embodiment, is designed to cool a semiconductor component. The semiconductor component can be understood as a semiconductor or an electronic component which, according to one embodiment, is shaped as a chip. According to one embodiment, the cooling fluid can comprise a liquid such as water and / or a gas. A heat sink can be understood as a heat spreader designed to dissipate the largest possible amount of heat quickly. According to one embodiment, the heat sink can be made of copper. Copper is a particularly good thermal conductor, which is advantageous for cooling. According to one embodiment, two or more cooling structures can also be arranged on the heat sink. According to one embodiment, the cooling structure can also be made of copper and, for example, be manufactured integrally with the heat sink.The heat absorption area can be understood as an area next to (for example, in the flow direction of a fluid flowing in the fluid channel during operation) a cooling structure or between two cooling structures, which, according to one embodiment, is shaped to accommodate the semiconductor device.

[0007] In one embodiment, the cooling element's cooling structure can be arranged at least partially upstream of the heat absorption area in the fluid flow direction. In another embodiment, the cooling structure can be arranged at least partially downstream of the heat absorption area in the fluid flow direction. This distributes the generated heat and allows it to be dissipated more quickly.

[0008] The cooling structure can be designed as a plurality of fingers and / or ribs extending into the interior of the cooling channel. This gives the cooling structure a larger surface area in contact with the fluid. The more surface area interacting with the fluid, the more efficiently the cooling structure is cooled.

[0009] According to one embodiment, the heat sink can be arranged on a printed circuit board, the circuit board being attached to a wall of the cooling channel. Such an embodiment offers the advantage of being able to securely and firmly attach the cooling element to a wall of the cooling channel. At the same time, the circuit board can also be used to electrically contact, for example, a semiconductor device.

[0010] According to one embodiment, the heat sink can be glued, soldered, or sintered onto the circuit board. This allows the use of already known manufacturing methods. Additionally, a particularly cost-effective manufacturing method can be chosen, since the connection between the heat sink and the circuit board does not necessarily need to be highly thermally or electrically conductive.

[0011] According to a further embodiment, a semiconductor device can be provided comprising a cooling element and a semiconductor device, wherein the semiconductor device is arranged on the heat sink in the heat absorption area. This allows heat to be dissipated directly from the semiconductor device into the cooling element, partly via the heat sink and partly directly via a fluid flowing in the fluid channel, resulting in rapid cooling of the semiconductor device.

[0012] According to another embodiment, the thermal resistance between the heat sink and the circuit board can be lower than the thermal resistance between the semiconductor device and the heat absorption area. Such an embodiment offers the advantage of a very flexible choice of materials for connecting the circuit board to the heat sink, as well as for connecting the cooling element to the semiconductor device.

[0013] A method for manufacturing a cooling element according to an embodiment of the approach presented here may comprise a step of providing a heat sink with at least one cooling structure, wherein the cooling structure is arranged at or forms an end of the heat sink, and wherein the heat sink has a heat absorption area for heat of a semiconductor device, which is or can be arranged laterally offset to the cooling structure in the cooling channel, the semiconductor device being arranged on the heat sink in the heat absorption area. Furthermore, the manufacturing method may comprise a step of attaching the provided heat sink to a cooling channel to be formed, such that the cooling structure extends into the interior of the cooling channel to manufacture the cooling element.

[0014] A method for operating a semiconductor device may comprise a step of driving the semiconductor device and a step of activating a fluid flow onto the cooling structure of the heat sink to cool the cooling structure in order to operate the semiconductor device. According to one embodiment, the steps of the operating method may be performed repeatedly.

[0015] The approach presented here further creates a control unit designed to execute, control, and implement the steps of a variant of the method presented here in appropriate devices. This embodiment of the invention, in the form of a control unit, also allows the underlying problem to be solved quickly and efficiently.

[0016] A control unit can be an electrical device that processes electrical signals, such as sensor signals, and outputs control signals accordingly. The control unit can have one or more suitable interfaces, which can be implemented in hardware and / or software. In hardware implementations, the interfaces can, for example, be part of an integrated circuit in which the control unit's functions are implemented. The interfaces can also be dedicated integrated circuits or consist at least partially of discrete components. In software implementations, the interfaces can be software modules, such as those found on a microcontroller alongside other software modules.

[0017] A computer program product with program code that can be stored on a machine-readable medium such as semiconductor memory, hard disk memory or optical memory and is used to carry out the method according to one of the embodiments described above is also advantageous when the program is executed on a computer or control unit.

[0018] The invention is explained in more detail by way of example with reference to the accompanying drawings. These show: Fig. 1 a schematic representation of an embodiment of a cooling element; Fig. 2. A flowchart of an exemplary embodiment of a manufacturing process for a cooling element; and Fig. 3 a flowchart of an exemplary embodiment of a method for operating a semiconductor component.

[0019] In the following description of preferred embodiments of the present invention, the same or similar reference numerals are used for the elements depicted in the various figures and having a similar effect, thus omitting a repeated description of these elements. The embodiments described and shown in the figures are chosen only as examples. Different embodiments can be combined completely or with respect to individual features. An embodiment can also be supplemented by features of another embodiment.

[0020] Fig. Figure 1 shows a schematic representation of an embodiment of a cooling element 100. The cooling element 100 has a circuit board 105, which is connected to a heat sink 110. The heat sink 110 has two cooling structures 115, each located opposite one end of the heat sink 110 or forming such an end. A semiconductor device 120 is arranged between the two cooling structures 115. The circuit board 105 is attached to a wall of a cooling channel 125. During operation of the cooling element, a fluid flow 130, shown here as arrows, flows in the cooling channel 125. It is also conceivable that the cooling element 100 has only one cooling structure 115, which is arranged, for example, upstream or downstream of the semiconductor device 120 in the direction of the fluid flow 130.

[0021] The semiconductor device 120 heats up when it is active. According to one embodiment, the heat sink 110 is shaped to absorb and dissipate heat from the semiconductor device 120. According to the embodiment described in the Fig. In the embodiment shown in Figure 1, the heat sink 110 for the semiconductor device 120 has a heat absorption area 135 for heat from the semiconductor device 120. To create a thermally conductive connection between the semiconductor device 120 and the heat sink 110, the semiconductor device 120 is soldered, glued, and / or sintered onto this heat absorption area 135, according to one embodiment. The heat is thus efficiently distributed over the entire length of the heat sink 110. At each end of the heat sink 110, according to the illustration in Figure 1, a heat sink is provided. Fig. In the illustrated embodiment 1, cooling structures 115 are arranged. Here, too, the cooling structures 115 are connected to the heat sink 110 in such a way that as much heat as possible can be transferred, for example by soldering or sintering. It is also conceivable that the cooling structures 115, or at least one cooling structure 115, are manufactured integrally with the heat sink 110.

[0022] According to one embodiment, the cooling structure 115 forms a plurality of fingers or ribs which are connected to the heat sink 110. The heat sinks 110 extend from the heat sink 110 into the interior of the cooling channel 125. Due to the plurality of ribs, the cooling structure 115 has a large contact area for contacting the fluid of the fluid flow 130, which, according to one embodiment, is shaped to transfer heat to the fluid of the fluid flow 130. To ensure the most efficient cooling possible, the semiconductor device 120 is arranged laterally offset from the cooling structure 115 in the cooling channel 125, so that at least one semiconductor device 120 can also be cooled by the fluid of the fluid flow 130. The fluid can be, for example, a liquid or a gas.

[0023] The semiconductor device 120 is manufactured according to the one described in the Fig. In the embodiment shown in Figure 1, the semiconductor device 120 is controlled by a control unit 140. For this purpose, the control unit 140 sends a control signal 145 to the semiconductor device 120. The control unit 140 also sends an activation signal 150 to the fluid flow 130, which is emitted in response to the activation of the semiconductor device 120. As the fluid moves within the fluid flow 130, heat is absorbed and dissipated by the cooling structure 115, the heat sink 110, and / or the semiconductor device 120. Thus, several advantageous scenarios can occur. Higher cooling performance can be achieved under otherwise identical conditions, and / or a higher maximum cooling capacity can be achieved. If these scenarios do not occur, a shorter cooling channel 125 can be constructed while maintaining the same cooling performance, or the pressure drop can be kept very low.Less pressure drop results in higher reliability and lower required pumping power, which saves energy.

[0024] Such a design of a cooling element according to the one described in the Fig. The variant shown in Figure 1 is advantageous because the power dissipation density of modern semiconductors is constantly increasing in many applications (HPC, AI, CPUs / GPUs, and also power electronics), and with it the requirements for heat dissipation. A low thermal resistance up to the heat sink is desirable, as this positively influences the maximum current, the trace resistance, and the component's lifetime. Direct flow of a suitable liquid around the semiconductor 120 offers significantly better heat dissipation than, for example, heat dissipation solely through the cooling structure. The cooling performance can be increased by the approach presented here by using a novel combination of a heat spreader 110 and a cooling structure 115 within the cooling channel 125.

[0025] Direct liquid cooling in power electronics, on the other hand, is still in the research stage, but the technology is already used in data centers at much lower voltages. Due to the high voltages (>1000V), the insulating properties of the coolant are of particular importance.

[0026] An important aspect of the approach presented here is that heat is not only dissipated by the liquid or fluid, but can also be dissipated through the chip or semiconductor component. The heat is also distributed above the circuit board or printed circuit board via a highly thermally conductive heat spreader (e.g., made of copper) and transferred to the liquid or fluid by cooling structures 115 with the largest possible surface area. The semiconductor chips are soldered, glued, or sintered onto the heat spreader, with the connection needing to be as thermally conductive as possible. The heat spreader itself is also either glued or soldered to the circuit board; this connection does not necessarily need to be highly thermally or electrically conductive, but good electrical conductivity is advantageous.

[0027] Fig. Figure 2 shows a flowchart of an embodiment of a manufacturing process 200 for a cooling element. According to one embodiment, the cooling element can be produced by the process shown in Fig. The manufacturing process 200 comprises a step 210 of providing a heat sink with at least one cooling structure, wherein the cooling structure is arranged at or forms an end of the heat sink, and wherein the heat sink has a heat absorption area for heat of a semiconductor device, which is or can be arranged laterally offset to the cooling structure in the cooling channel, the semiconductor device being located on the heat sink in the heat absorption area. Furthermore, the process 200 comprises a step 230 of attaching the provided heat sink to a wall of a cooling channel to be formed, such that the cooling structure extends into an interior of the cooling channel to produce the cooling element, wherein the attaching step 230 is performed following the providing step 210.

[0028] Fig.Figure 3 shows a flowchart of an embodiment of a method 300 for operating a semiconductor device. The method 300 comprises a step 310 of controlling the semiconductor device, followed by a step 330 of activating a fluid flow onto the cooling structure of the heat sink in order to cool the cooling structure in order to operate the semiconductor device.

[0029] Furthermore, the process steps according to the invention can be repeated and carried out in a different order than described.

[0030] If an embodiment includes an “and / or” connection between a first feature and a second feature, this can be interpreted as meaning that the embodiment according to one embodiment has both the first feature and the second feature, and according to another embodiment either only the first feature or only the second feature. Reference sign 100 cooling elements 105 circuit board 110 heat sinks 115 Cooling structure 120 semiconductor components 125 Cooling channel 130 Fluid flow 135 Heat absorption area 140 control unit 145 Control signal 150 Activation signal 200 manufacturing processes 210th step of deployment 230 Step of fastening 300 procedures for operating 310th step of the approach Step 330 of the activating process

Claims

[1] Cooling element (100) for a semiconductor device (120), characterized by the following features: - a cooling channel (125) for guiding a cooling fluid; and - a heat sink (110) with at least one cooling structure (115), wherein the cooling structure (115) is arranged at or forms such an end of the heat sink (110) and extends into an interior of the cooling channel (125), and wherein the heat sink (110) has a heat absorption area (135) for heat from the semiconductor device (120), which is arranged laterally offset to the cooling structure (115) in the cooling channel (125). [2] Cooling element (100) according to one of claim 1, characterized by that the cooling structure (115) is arranged at least partially in front of the heat absorption area (135) in the direction of fluid flow. [3] Cooling element (100) according to any one of the preceding claims, characterized bythat the cooling structure (115) is arranged at least partially downstream of the heat absorption area (135) in the direction of fluid flow. [4] Cooling element (100) according to any one of the preceding claims, characterized by , that the cooling structure (115) is designed at least as a plurality of fingers and / or ribs extending into the interior of the cooling channel (125). [5] Cooling element (100) according to any one of the preceding claims, characterized by , that the heat sink (110) is arranged on a circuit board (105) which is attached to a wall of the cooling channel (125). [6] Cooling element (100) according to claim 5, characterized by , that the heat sink (110) is glued and / or soldered and / or sintered onto the circuit board (105). [7] Semiconductor device with a cooling element (100) according to 1 to 6, and a semiconductor device (120) which is arranged in the heat absorption area (135) on the heat sink (110). [8] Semiconductor device according to claim 7, characterized by , that a thermal resistance between the heat sink (110) and the circuit board (105) is lower than a thermal resistance between the semiconductor device (120) and the heat absorption area (135). [9] Method (200) for manufacturing a cooling element (100) according to any one of claims 1 to 6, wherein the method (200) is characterized by the following steps: - Providing (210) a heat sink (110) with at least one cooling structure (115), wherein the cooling structure (115) is arranged at one end of the heat sink (110), wherein the heat sink (110) has a heat absorption area (135) for heat of a semiconductor device (120) which is or can be arranged laterally offset to the cooling structure (115) in the cooling channel (125), wherein the semiconductor device (120) is arranged on the heat sink (110) in the heat absorption area (135); - Attaching (230) the provided heat sink (110) to a wall of a cooling channel (125) to be formed, such that the cooling structure (115) extends into an interior of the cooling channel (125) to produce the cooling element (100). [10] Method (300) for operating a semiconductor device according to one of claims 7 or 8, characterized by the following steps: - Controlling (310) the semiconductor device (120); and - Activating (330) a fluid flow (130) onto the cooling structure (115) of the heat sink (110) to cool the cooling structure (115) in order to operate the semiconductor device. [11] Control unit (140) configured to perform and / or control the steps (210, 230; 310, 320) of at least one of the methods (200; 300) according to claim 9 or 10 in corresponding units. [12] Computer program configured to perform and / or control the steps (210, 230; 310, 320) of at least one of the methods (200; 300) according to one of the preceding claims. [13] Machine-readable storage medium on which the computer program according to claim 12 is stored.

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