Cooling structure, method for manufacturing a cooling structure, cooling device and method for manufacturing a cooling device

Abstract

A cooling structure (120) for a semiconductor device (140) has a flat receiving surface (130) for receiving the semiconductor device (140) and a plurality of fingers (150) which extend away from the receiving surface (130), wherein the receiving surface (130) and the plurality of fingers (150) are formed in one piece from a metal element in the form of a metal sheet or a metal foil and wherein the plurality of fingers (150) are bent upwards relative to the receiving surface (130).

Description

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

[0002] Cooling structures are used to cool electronic components.

[0003] The state of the art is disclosed in DE 14 64 689 A, US 4 552 206 A and US 2012 / 0 223 070 A1.

[0004] Against this background, the present invention provides an improved cooling structure, an improved method for manufacturing a cooling structure, an improved cooling device, and an improved method for manufacturing a cooling device according to the main claims. Advantageous embodiments will become apparent from the dependent claims and the following description.

[0005] A cooling structure allows heat to be distributed and dissipated from the semiconductor component.

[0006] A cooling structure for a semiconductor device has a flat receiving surface for receiving the semiconductor device and a plurality of fingers extending away from the receiving surface. The receiving surface and the plurality of fingers are formed in one piece from a metal element in the form of a metal sheet or a metal foil, and the plurality of fingers are bent upwards relative to the receiving surface.

[0007] The cooling structure can be made of a highly thermally conductive material, such as copper. According to one embodiment, the flat receiving surface is centrally located on the cooling structure. This flat receiving surface is shaped to accommodate the semiconductor device. The semiconductor device can be understood as a semiconductor chip that expands during operation. The heat generated during operation can be dissipated using the cooling structure, for example, to a cooling fluid flowing around the fingers. Advantageously, the entire cooling structure can be formed from the flat, for example, rectangular, metal element by providing slots in the metal element and then bending the segments exposed by the slots to form the protruding fingers. Thus, the cooling structure can be manufactured using a stamping-bending process.

[0008] The majority of fingers can be arranged laterally offset along a length and / or width of the cooling structure. According to one embodiment, the majority of fingers thus extend around all four sides of the cooling structure. This allows the heat emanating from the semiconductor device to be dissipated particularly efficiently.

[0009] According to one embodiment, the multiple fingers can protrude from the receiving surface in various directions. This is particularly advantageous for liquid cooling, as it creates a larger contact area between the multiple fingers and the cooling fluid.

[0010] The majority of the fingers are bent upwards at acute angles relative to the receiving surface. This allows the receiving surface and the fingers to be oriented obliquely to each other. As a result, a volume extending laterally around the receiving surface can also be used for cooling. The majority of the fingers protrude from the receiving surface at various angles.

[0011] A cooling device can comprise a cooling structure and a semiconductor device, wherein the semiconductor device is metallurgically bonded to the receiving surface of the cooling structure. The metallurgical bond between the semiconductor device and the cooling structure ensures good heat transfer and a reliable connection.

[0012] According to one embodiment, the cooling device can have a support plate, in particular a copper plate, which is attached to the cooling structure opposite the receiving surface.

[0013] According to one embodiment, the support plate can be at least partially bent and form a section of a cooling channel. This allows the cooling structure to be connected to a cooling channel. According to another embodiment, the cooling structure can be located inside the cooling channel, so that the fingers can be surrounded by a cooling fluid flowing through the cooling channel.

[0014] A method for manufacturing a cooling structure for a semiconductor element comprises a step of providing a metal element in the form of a metal plate or metal foil, a step of making a plurality of cuts in the metal element to form a plurality of segments, and a step of bending the plurality of segments to form a flat receiving surface for receiving the semiconductor device and a plurality of fingers extending away from the receiving surface.

[0015] The cuts can be made, for example, by punching or forming them using a laser beam. The cuts can be made in such a way that, apart from the cut areas, no material is removed from the metal element; for example, no segment of the metal element is completely separated. A suitable bending tool can be used to bend the segments open.

[0016] During the insertion step, the majority of cuts can include initial cuts that extend to an edge of the metal element. Furthermore, the majority of cuts can include secondary cuts that do not extend to an edge of the metal element. In this way, branching fingers can also be created. For example, a secondary cut can intersect at least one initial cut.

[0017] A method for manufacturing a cooling device comprises a step of providing said cooling structure and a step of bonding a semiconductor device to the receiving surface of the cooling structure. Additionally or alternatively, in the bonding step, the cooling structure is connected to a support plate.

[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 device; Fig. 2 a schematic view of an embodiment of a cooling structure from above; Fig. 3 a schematic representation of an embodiment of a cooling structure in a cooling channel; Fig. 4. A flowchart of a process for manufacturing a cooling structure for a semiconductor device; and Fig. 5 a flowchart of a process for manufacturing a cooling device.

[0019] In the following description of preferred embodiments of the present invention, the same or similar reference numerals are used for the elements shown in the various figures and having a similar effect, without repeating these elements.

[0020] Fig. Figure 1 shows a schematic representation of an embodiment of a cooling device 100. The cooling device 100 comprises a carrier plate 110 on which a cooling structure 120 is arranged. The cooling structure 120 has a receiving surface 130. A semiconductor device 140 is arranged on the receiving surface 130. Opposite the receiving surface 130, the cooling structure 120 is connected to the carrier plate 110. Furthermore, the cooling structure 120 divides into a plurality of fingers 150 adjacent to the receiving surface 130. For example, the semiconductor device 140 is metallurgically bonded to the cooling structure 120, and the cooling structure 120 is metallurgically bonded to the carrier plate 110.

[0021] The support sheet is, for example, a copper or aluminum sheet and exhibits good thermal conductivity. According to one embodiment, the support sheet 110 is bent and formed as part of a cooling channel.

[0022] According to one embodiment, the cooling structure 120 is formed from copper. The cooling structure 120 is formed in one piece, so that the receiving surface 130 and the plurality of fingers 150 are manufactured from a single part. The receiving surface 130 is planar and designed to receive the semiconductor device 140. According to one embodiment, the plurality of fingers 150 extend away from the receiving surface 130 and are bent upwards relative to the receiving surface 130. In one embodiment, the plurality of fingers 150 are oriented obliquely relative to the receiving surface 130.

[0023] The cooling structure 120 is suitable for direct liquid cooling. For this purpose, the majority of the fingers 150 are used as cooling fins, similar to conventional heat sinks. Since the majority of the fingers 150 can be bent open using a bending process, milling from solid material is unnecessary, thus enabling efficient manufacturing.

[0024] Fig. Figure 2 shows a schematic top view of an embodiment of an unbent cooling structure 120. According to one embodiment, the cooling structure 120, when bent, can provide the cooling capacity described in Fig. Form the cooling structure described in 1. The cooling structure 120 is therefore not yet fully formed here, since the majority of fingers have not yet been bent, and thus, according to one embodiment, is still formed as a plurality of segments 200 in a metal element 210.

[0025] To manufacture the cooling structure 120, a metal element 210, for example a sheet or foil, is first provided. Then, to form the segments 200, cuts 260, 270 are made into the metal element 210 so that the segments 200 can be bent open to form the fingers of the cooling structure 120. The cuts 260, 270 form so-called bending slots in the metal element 210. Initial cuts 260 are made that extend to the edges of the metal element 210. For example, a first number of initial cuts 260 are made, here for example five initial cuts 260, extending to a first edge, and a second number of initial cuts 260 are made, here for example five initial cuts 260, extending to a second edge opposite the first edge.

[0026] The first cuts 260, extending to the first edge, are aligned parallel to each other according to one embodiment and optionally have the same distance between them. The length of these first cuts 260 corresponds, for example, to between one-third and two-thirds of the distance between the first edge and the support surface 130.

[0027] The first cuts 260, extending to the second edge, are aligned parallel to each other according to one embodiment and optionally have the same distance between them. The length of these first cuts 260 corresponds, for example, to between one-third and two-thirds of the distance between the second edge and the support surface 130.

[0028] For example, only a single first cut 260 is made, extending to a third edge connecting the first and second edges, and only a single first cut 260 is made, extending to a fourth edge opposite the third edge. The length of these first cuts 260 corresponds, for example, to more than half or more than two-thirds of the distance between the third edge and the support surface 130, or between the fourth edge and the support surface 130.

[0029] For example, the first cuts 260 are each aligned at right angles to the edges to which the first cuts 260 extend.

[0030] According to one embodiment, second cuts 270 are made that do not extend to the edges of the metal element 210. For example, two second cuts 270 are made that intersect the first cut 260 extending from the third edge, here intersecting it at right angles. One of the second cuts 270 intersects this first cut 260 at its midpoint, and the other of the second cuts 270 intersects an end of this first cut 260 adjacent to the bearing surface 130.

[0031] As an example, two second cuts 270 are also made, which intersect the first cut 260 extending from the fourth edge, here intersecting it at right angles. One of the second cuts 270 intersects this first cut 260 in the middle, and the other of the second cuts 270 intersects an end of this first cut 260 adjacent to the support surface 130.

[0032] The number, orientation, shape and arrangement of cuts 260, 270 are merely examples.

[0033] Advantageously, cuts 260 and 270 allow for a simple realization of the cooling structure 120 as a multiply bent copper sheet.

[0034] Depending on the embodiment, the semiconductor component 140 is applied to the support surface 130 before or after the segments 200 are bent towards the fingers.

[0035] According to one embodiment, the plurality of segments 200 are arranged around the semiconductor device 140. The plurality of segments 200 are formed by punching or cutting out a pattern around the semiconductor device 140 according to one embodiment. The pattern is formed, for example, by the first cuts 260 originating from the edges of the metal element 210, wherein at least some of the first cuts 260 are in turn intersected by second cuts 270, which do not originate from the edges.

[0036] According to one embodiment, adjacent segments 200 are only separated from each other by the respective intervening sections 260, 270.

[0037] According to one embodiment, the cooling structure 120, which exemplifies a heat spreader cooling structure for direct liquid cooling of the semiconductor component 140 in the form of a semiconductor chip, is stamped from the metal element 210 in the form of a copper sheet.

[0038] As an example, the cooling structure 120, which can be used as a heat exchanger, is stamped from copper sheet or copper foil and bent accordingly. Slots 260 and 270 are punched into the metal element 120 so that the individual segments 200 can be bent open and thus act like cooling fins.

[0039] This can be advantageously achieved through a cost-effective stamping process instead of a milling process, resulting in minimal material waste and making it possible to use a wide variety of materials. Therefore, instead of copper, other suitable materials can be used, such as other metals with good thermal conductivity.

[0040] Fig. Figure 3 shows a schematic representation of an embodiment of a cooling structure 120 in a cooling channel 300. According to one embodiment, the cooling structure 120 is the one described in Fig. 1. Cooling structure described. The cooling channel 300, in which the cooling structure 120 is arranged, is exemplified by being installed in an electronic device 310.

[0041] According to one embodiment, the electronic device 310 is designed as a power converter for an axle drive for a vehicle.

[0042] The cooling structure 120 can be cooled by a fluid via the cooling channel 300 by generating a fluid flow in the closed system. Depending on the embodiment, the fluid can be a liquid or a gas.

[0043] This is merely an example based on Fig. The copper plate 110 described above forms a wall of the cooling channel 300. Thus, a side of the cooling structure 120 opposite the semiconductor device is connected to an inner wall of the cooling channel 300.

[0044] Fig. Figure 4 shows a flowchart of a process 400 for manufacturing a cooling structure for a cooling structure. According to one embodiment, the cooling structure is the one in Fig. 1 described cooling structure.

[0045] Method 400 for manufacturing the cooling structure comprises a step 410 of providing a metal element, wherein the metal element is formed as a metal plate or a metal foil according to an exemplary embodiment.

[0046] Responding to step 410 of the provisioning, step 430 of making cuts into the metal element is performed to form a plurality of segments. For example, this is done using the following: Fig. Two patterns of cuts are shown, for example punched.

[0047] In step 450, the segments released by the cuts are bent open. This leaves the flat receiving surface as an unbent section of the metal element, while the segments are bent open to form the fingers. The segments are bent open to such an extent that at least some of the fingers are oriented obliquely to the flat receiving surface.

[0048] Fig. Figure 5 shows a flowchart of a method 500 for manufacturing a cooling device. The cooling device can be constructed according to an embodiment of the method described in Figure 500. Fig. 1 correspond to the cooling device described.

[0049] The manufacturing process 500 comprises a step 530 of providing a cooling structure and a step 532 of joining a semiconductor device to the receiving surface of the cooling structure by means of a material bond, and additionally or alternatively a step 534 of attaching the cooling structure to a carrier sheet. Steps 532 and 534 can be performed in any order.

[0050] According to one embodiment, method 500 comprises the steps of the procedure based on Fig. The procedure described in section 4 for manufacturing a cooling structure is used. In this case, step 532 of connecting the semiconductor device is optionally performed before step 430 of making cuts or before step 450 of bending. Reference sign 100 Cooling device 110 copper plates 120 cooling structure 130 recording area 140 semiconductor device 150 Plural of fingers 200 Plural of segments 210 metal element 260 first cuts 270 second cuts 300 cooling channel 310 electronic device 400 methods for manufacturing the cooling structure Step 410 of providing a metal element Step 430 of the insertion process 450 steps of bending 500 methods for manufacturing a cooling device Step 530 of deploying a cooling structure Step 532 of connecting

Claims

[1] Cooling structure (120) for a semiconductor device (140), the cooling structure having the following features: a planar receiving surface (130) for receiving the semiconductor component (140); and a plurality of fingers (150) extending away from the receiving surface (130), wherein the receiving surface (130) and the plurality of fingers (150) are formed integrally from a metal element (210) in the form of a metal sheet or a metal foil, and wherein the plurality of fingers (150) are bent at acute angles relative to the receiving surface (130), wherein the plurality of fingers (150) protrude at different angles from the receiving surface (130). [2] Cooling structure (120) according to claim 1, wherein the plurality of fingers (150) are arranged laterally offset along a length of the cooling structure (120) and / or along a width of the cooling structure (120). [3] Cooling structure (120) according to one of the preceding claims,characterized by that the plurality of fingers (150) protrude in different directions from the receiving surface (130). [4] Cooling device (100) having the following features: a cooling structure (120) according to one of the preceding claims; and the semiconductor component (140) which is integrally connected to the receiving surface (130) of the cooling structure (120). [5] Cooling device (100) according to claim 5, wherein the cooling device (100) comprises a carrier plate (110), in particular a copper plate, which is fastened to the cooling structure (120) opposite the receiving surface (130). [6] Cooling device (100) according to claim 6, wherein the carrier sheet (110) is at least partially bent and forms a portion of a cooling channel (300) enclosing the cooling structure (120). [7] A method (400) for producing a cooling structure (120) for a semiconductor device (140), the method (400) comprising the following steps: Providing (410) a metal element (210) in the form of a metal plate or a metal foil; Making (430) a plurality of cuts (260, 270) in the metal element (210), to form a plurality of segments (200); and Bending (450) the plurality of segments (200) to form a planar receiving surface (130) for receiving the semiconductor device (140), and a plurality of fingers (150) extending away from the receiving surface (130). [8] A method (400) for manufacturing a cooling structure (120) according to claim 8, wherein in the step (430) of introducing, the plurality of cuts comprises first cuts (260) that extend to an edge of the metal element (210) and second cuts (270) that do not extend to an edge of the metal element (210). [9] Method (500) for manufacturing a cooling device (100), the method (500) comprising the following steps: Providing (530) a cooling structure (120) according to one of claims 1 to 4; and Connecting (532) a semiconductor component (140) in a material-to-material manner to the receiving surface (130) of the cooling structure (120) and / or the cooling structure (120) to a carrier sheet (110).

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