Power semiconductor device with contact device and manufacturing process therefor

Abstract

Power semiconductor device (2) with a contact device (3), wherein the power semiconductor device (2) has a first main surface (200) defining a normal direction (N), with a first load connection surface (22) and with a centrally arranged control connection surface (24) separated from the first load connection surface (22) by a first insulating surface (26), and a second main surface (202) with a second load connection surface (28), wherein the contact device (3) is designed as a planar shaped body with a first and a second main surface (300, 302), wherein the shaped body has a first and a second centrally arranged metal shaped body (32, 34) and an insulating shaped body (36) arranged between them when viewed in the normal direction (N),wherein the contact device (3) with its second main surface (302) is arranged on the first main surface (200) of the power semiconductor device (2) and the first metal body (32) is electrically connected to the load connection surface (22) and the second metal body (34) to the control connection surface (24).

Description

[0001] The invention relates to a power semiconductor device with a contact device, wherein the power semiconductor device has a first main surface defining a normal direction N, with a first load connection surface and with a centrally arranged control connection surface, which is separated from the first load connection surface by a first insulating surface, and a second main surface with a second load connection surface, wherein the contact device is designed as a planar shaped body with a first and a second main surface, wherein the shaped body comprises a metal shaped body, wherein the contact device is arranged with its second main surface on the first main surface of the power semiconductor device and the metal body is electrically connected to the load connection surface.The invention further relates to a method for manufacturing such a power semiconductor device with a contact device arranged thereon.

[0002] From the prior art, specifically disclosed in DE 10 2005 047 566 A1, an arrangement is known comprising at least one power semiconductor device and an electrically insulating housing, as well as externally leading connection elements and a substrate at least partially enclosed by the housing. The power semiconductor device has at least one contact surface with a metallization layer of a noble metal on its first main surface facing away from the substrate. The metal body also has a noble metal layer on its second main surface facing the power semiconductor device. These are connected to each other by means of a pressure sintering process.The associated manufacturing process is characterized by the essential step that the metal mold bodies are arranged on the power semiconductor components in the wafer composite and a plurality of these arrangements are simultaneously subjected to pressure, thus creating the pressure sintering connection for several of these arrangements simultaneously.

[0003] DE 10 2011 115 887 A1 discloses a power semiconductor chip with at least one upper potential surface and contacting thick wires or ribbons, with a bonding layer on the potential surfaces, and at least one metallic shaped body on the bonding layer(s), the lower flat side of which facing the potential surface is coated for joining with a bonding method of the bonding layer according to, and whose material composition and thickness are selected to be of the same order of magnitude as those of the thick wires or ribbons used in the contact method on the upper side of the shaped body.

[0004] DE 10 2014 117 086 A1 discloses an electronic component comprising an electrically conductive mounting structure, an electronic chip on the mounting structure, an electrically conductive redistribution structure on the electronic chip and a peripheral connection structure that is electrically coupled to the redistribution structure and designed for connecting the electronic component to an electronic peripheral, wherein at least the electrically conductive mounting structure or the electrically conductive redistribution structure comprises electrically conductive inserts in an electrically insulating matrix.

[0005] DE 10 2019 112 477 A1 discloses a power semiconductor device with a contact device, wherein the power semiconductor device has a load connection area and a control connection area with a control connection area boundary on a first main surface with a normal direction, wherein the contact device is designed as a layer stack with a first and a second electrically conductive layer and a first electrically insulating layer arranged between them, wherein the first electrically conductive layer has a first load layer and a first control layer, wherein the first load layer is electrically connected to the load connection area and the control layer is electrically connected to the control surface, wherein the second electrically conductive layer has a second load layer and a second control layer, the latter having a first section that is aligned in the normal direction with the control surface.a second section whose control conductor layer boundary is laterally offset in projection in the normal direction to the control connection surface boundary and a third section which connects the first and second sections together and wherein the first insulating layer has a first via between the first and second load layer and a second via between the first and second control conductor layer.

[0006] DE 10 2014 117 246 A1 discloses a method for manufacturing a substrate adapter, which is used in particular for contacting semiconductor elements, comprising the steps: structuring an electrically conductive metal element, at least partially encasing the structured metal element with an electrically insulating material, in particular plastic, and applying a contacting material to a first side of the metal element.

[0007] EP 2 963 682 A1 discloses a semiconductor device featuring excellent connection reliability between a main electrode and a control electrode, which are provided on a main surface of a semiconductor element, and connecting wiring. The control electrode and a main electrode are each electrically connected to the connecting wiring in wire or tape form via a conductive element. The connecting wiring is divided into a conductive element for the control electrode and a conductive element for the main electrode, wherein the conductive element for the control electrode and the conductive element for the main electrode are secured by an insulating element.

[0008] DE 102 49 855 A1 discloses a material for supplying current to a semiconductor, wherein the material has a material coefficient of thermal expansion and a material modulus of elasticity and can be electrically contacted and attached to at least a part of the semiconductor in such a way that the current is conducted through the material as a conductor into the semiconductor, and the material of the semiconductor has a semiconductor coefficient of thermal expansion and a semiconductor modulus of elasticity.

[0009] The invention is based on the objective of presenting an improved power semiconductor device with a contact device and a manufacturing method for it.

[0010] This problem is solved according to the invention by a power semiconductor device with a contact device, wherein the power semiconductor device has a first main surface, which defines a normal direction, with a first load connection surface and with a centrally arranged control connection surface, which is separated from the first load connection surface by a first insulating surface, and a second main surface with a second load connection surface, wherein the contact device is designed as a planar molded body with a first and a second main surface, wherein the molded body has a first and a second centrally arranged metal molded body and an insulating molded body arranged between them when viewed in the normal direction.wherein the contact device is arranged with its second main surface on the first main surface of the power semiconductor device and the first metal body is electrically connected to the load connection surface and the second metal body to the control connection surface.

[0011] The insulating body can be made of ceramic or plastic.

[0012] The electrically conductive connection between the first metal component and the first load connection surface preferably connects at least 90% of this first load connection surface. The electrically conductive connection between the second metal component and the control connection surface preferably connects at least 90% of this control connection surface.

[0013] It can be advantageous if the contact device, viewed in the normal direction, does not overlap the power semiconductor device laterally, in an edge region. It is particularly advantageous if an insulating compound is arranged on the edge region and in contact with an edge area of ​​the contact device.

[0014] It may be preferable if the metal molded parts are connected to the insulating molded part without gaps.

[0015] It may also be preferred if the first load connection surface is formed by a plurality of partial connection surfaces, each with second insulation surfaces arranged between the partial connection surfaces.

[0016] It can be advantageous if the first metal molded body has a channel-like recess on its second main surface, extending from the outside towards the insulating molded body. It can be particularly advantageous if, viewed in the standard direction, the recess is flush with the second insulating surface.

[0017] In principle, it may be preferred if the contact element has a thickness between 0.05 mm and 0.7 mm, preferably between 0.2 mm and 0.5 mm. It may also be advantageous if the thickness of the contact element is between 0.5 and 5 times the thickness of the power semiconductor device.

[0018] It may also be generally preferred if the first main surface or the second main surface or both main surfaces of the contact device have a roughness, according to ISO 4287, with a mean roughness value of 2 µm to 20 µm, section by section or completely.

[0019] The problem is further solved by a method for manufacturing a specified power semiconductor device with the following process steps: a. Provision of the power semiconductor device; b. Training of the contact facility; c. Forming an electrically conductive connection between the power semiconductor component and the contact device.

[0020] Advantageously, a minimum area of ​​90% of the first load connection surface is connected to the first metal molded body.

[0021] In this context, it can be advantageous if the electrically conductive connection is formed as a material-jointed connection, in particular as a soldered, glued or sintered connection, or as a force-fit connection using a pressure device.

[0022] In particular, it can be advantageous if, prior to step a), the first metal body is joined to the insulating formwork and the second metal body using an embossing process. Furthermore, it can be advantageous if the contact surfaces of the respective metal bodies to the insulating formwork, and alternatively or additionally the contact surfaces of the insulating formwork to the respective metal body, have a roughness with a mean roughness value, according to ISO 4287, of 5 µm to 20 µm.

[0023] Alternatively, it may be advantageous if, prior to step a), the shaped body is cut as a disc from a prefabricated profile body. For this purpose, the profile body can be designed as a square or round tube, which, when cut, forms the first metal shaped bodies. An insulating tube is arranged within this square or round tube, which, when cut, forms the insulating shaped bodies. A metal cylinder is arranged within this insulating tube, which, when cut, forms the second metal shaped body.

[0024] Of course, unless explicitly or per se excluded or contrary to the idea of ​​the invention, the features or groups of features mentioned in the singular may be present multiple times in the assembly or power semiconductor device according to the invention.

[0025] It is understood that the various embodiments of the invention, regardless of whether they are mentioned in connection with the power semiconductor device or with the manufacturing process, can be implemented individually or in any combination to achieve improvements. In particular, the features mentioned and explained above and below can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the present invention.

[0026] Further explanations of the invention, advantageous details and features, will become apparent from the following description of the invention contained in the Fig. 1 to 3 schematically illustrated embodiments of the invention, or of respective parts thereof. Fig. Figure 1 shows a power semiconductor device according to the invention with a contact device in a three-dimensional representation. Fig. Figure 2 shows a section through an arrangement of a power semiconductor device according to the invention with a contact device. Fig. Figure 3 shows a section through a further embodiment of a power semiconductor device according to the invention with a contact device. Fig. Figure 4 shows one step in the manufacturing process of a contact device.

[0027] Fig. Figure 1 shows a three-dimensional representation of a power semiconductor device 2 according to the invention, comprising a contact element 3. The power semiconductor device 2 has a first main surface 200, which defines a normal direction N. A control terminal 24 is arranged centrally on this first main surface 200. This control terminal 24 is surrounded by a first insulating surface 26, which separates the control terminal 24 from the first load terminal 22. In this embodiment, the first load terminal 22 is formed by a plurality of, more precisely, two partial terminal surfaces 220, between each of which a second insulating surface 27 is arranged.

[0028] The contact element 3 is designed as a planar shaped body with a first and a second main surface 300, 302. Here, the shaped body comprises a first and a second metal shaped body 32, 34 and an insulating shaped body 36 arranged between them, viewed in the normal direction N. The contact element 3 is shown here spaced apart from the power semiconductor device 2 for illustrative purposes only. In principle, the contact element 3 is arranged with its second main surface 302 on the first main surface 200 of the power semiconductor device 2, thereby electrically connecting the first metal body 32 to the load connection surface 22 and the second metal body 34 to the control connection surface 24. This electrically conductive connection is preferably designed as a material-fit or force-fit connection, as is customary in the field.For material-bonded connection options, soldering, adhesive bonding or sintering are particularly suitable, and for force-bonded connection options, a pressure device is suitable.

[0029] Fig. Figure 2 shows a section through an arrangement of a power semiconductor device 2 according to the invention with a contact device 3, wherein the section is along a direction AA with respect to the contact device 3 according to Fig. 1 is executed. The power semiconductor component 2 shown, as well as the contact device 3, exhibit the features described below. Fig. The embodiment described in section 1 is shown. The power semiconductor device 2 is arranged on a conductor track 12 of a standard power electronic substrate 1, for example an IMS substrate. Here, the second load connection surface 28, located on the second main surface 202, is electrically conductive and connected to this conductor track 12 in a standard manner.

[0030] The arrangement further comprises a connection device 5, which is conventionally designed as a wire bond connection or, as shown here, preferably as a foil composite of electrically conductive and electrically insulating foils 52, 54, 56. This foil composite has a via 540 aligned in the normal direction with the control connection surface 24 and the second metal formwork 34. The sections of the lower foil 52 of the foil composite are electrically conductive and materially or force-fit connected to the two metal formwork 32, 34 in accordance with the circuit configuration.

[0031] The contact element 3 has a thickness of approximately 0.4 mm, which is about four times the thickness of the power semiconductor component 2. Both main faces 300, 302 of the contact element 3 exhibit a roughness with a mean roughness value of 10 µm in sections, specifically in the area of ​​the surfaces of the two metal components 32, 34.

[0032] Fig. Figure 3 shows a section through a further embodiment of a power semiconductor device 2 according to the invention with a contact device 3, wherein the section is along a direction BB with respect to the contact device 3 according to Fig. 1 is executed.

[0033] The first metal form 32 has a channel-like recess 37 on its second main surface 302, extending from the outside towards the insulating form 36. This recess corresponds, viewed in the normal direction N, to the second insulating surface 27 of the power semiconductor device 2.

[0034] Furthermore, it is shown here that the contact device 3, viewed in the normal direction N, does not overlap the power semiconductor device 2 laterally in an edge region 204 and extends only to the edge of the first load connection surface 22. A preferably gel-like insulating compound can be arranged on this edge region 204 and in contact with an edge region 306 of the contact device 3, which also covers the laterally circumferential section 206 of the power semiconductor device 2.

[0035] Fig. Figure 4 shows a step in the manufacturing process of a contact device, which is carried out before process step a). The starting point is a first rod-like metal body, which is centered inside a second, tube-like metal body with, purely by way of example, a square outer contour. The surfaces of the two metal bodies facing each other each have a roughness with a mean roughness value of 8 µm.

[0036] The cavity between the two metal bodies is then filled with a plastic material, which subsequently hardens. The individual contact elements, one of which is shown, are then cut from this resulting profile body 6. This creates contact elements whose metal components 32, 34 are seamlessly connected to the insulating component 36.

[0037] Alternatively, though not shown, the first metal mold body 32 can be joined to the insulating mold body 36 and the second metal mold body 34 by an embossing process prior to step a). The insulating mold body (36) can preferably be made of a ceramic, ring-shaped material and have a roughness at its inner and outer edges with a preferred average roughness of 12 µm. It is also advantageous if the metal mold bodies (32, 34) have a greater thickness than the insulating mold body (36) before the embossing process. It is particularly preferred if, after the embossing process, the insulating mold body (36) still has a smaller thickness than at least one of the two metal mold bodies (32, 34).

Claims

[1] Power semiconductor device (2) with a contact device (3), wherein the power semiconductor device (2) has a first main surface (200) defining a normal direction (N), with a first load connection surface (22) and with a centrally arranged control connection surface (24) separated from the first load connection surface (22) by a first insulating surface (26), and a second main surface (202) with a second load connection surface (28), wherein the contact device (3) is designed as a planar shaped body with a first and a second main surface (300, 302), wherein the shaped body has a first and a second centrally arranged metal shaped body (32, 34) and an insulating shaped body (36) arranged between them when viewed in the normal direction (N),wherein the contact device (3) with its second main surface (302) is arranged on the first main surface (200) of the power semiconductor device (2) and the first metal body (32) is electrically connected to the load connection surface (22) and the second metal body (34) to the control connection surface (24). [2] Power semiconductor device according to claim 1, wherein the contact device (3) viewed in the normal direction (N) does not overlap the power semiconductor device (2) laterally, in an edge region (204). [3] Power semiconductor device according to claim 2, wherein an insulating compound is arranged on the edge region (204) and in contact with an edge region (306) of the contact device (3). [4] Power semiconductor device according to one of the preceding claims, wherein the metal components (32, 34) are connected to the insulation component (36) without gaps. [5] Power semiconductor device according to one of the preceding claims, wherein the first load connection surface (22) is formed by a plurality of partial connection surfaces (220) with second insulating surfaces (27) arranged between the partial connection surfaces (220). [6] Power semiconductor device according to one of the preceding claims, wherein the first metal form body (32) has on its second main surface a trough-like depression (37) extending from the outside to the insulation form body (36). [7] Power semiconductor device according to claims 5 and 6, wherein the recess (37) is aligned with one of the second insulating surfaces (27) when viewed in the normal direction (N). [8] Power semiconductor device according to one of the preceding claims, wherein the contact device (3) has a thickness between 0.05 mm and 0.7 mm, preferably between 0.2 mm and 0.5 mm. [9] Power semiconductor device according to one of the preceding claims, wherein the first main surface (300) or the second main surface (302) or both main surfaces (300,302) of the contact device (3) has a roughness section by section or completely with a mean roughness value of 2 µm to 20 µm. [10] Method for manufacturing a power semiconductor device (2) according to any one of the preceding claims comprising the following method steps: a. Provision of the power semiconductor device (2); b. Training the contact device (3); c. Forming an electrically conductive connection between the power semiconductor device (2) and the contact device (3). [11] Method according to claim 10, wherein the electrically conductive connection is formed as a material-jointed connection, in particular as a soldered, glued or sintered connection or as a force-fit connection by means of a pressure device. [12] Method according to one of claims 10 or 11, wherein, prior to step a), the first metal body (32) is joined to the insulation form body (36) and the second metal body (34) in an embossing process. [13] Method according to claim 12, wherein the connecting surfaces of the respective metal bodies (32, 34) to the insulating form body (36) and alternatively or additionally the connecting surfaces of the insulating form body (36) to the respective metal body (32, 34) have a roughness with a mean roughness value of 5 µm to 20 µm. [14] Method according to one of claims 10 or 11, wherein prior to step a) the shaped body is cut as a disk from a profile body (6).

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