CONTACT ASSEMBLY FOR AN ELECTRONIC COMPONENT, AND METHOD FOR PRODUCING AN ELECTRONIC COMPONENT

Abstract

A contact assembly for an electronic component includes a wiring substrate having an upper face, a lower face and at least one contact connection surface on the upper face. At least one bonding strip is provided for connection to the at least one contact connection surface. The at least one contact connection surface is disposed on at least one metal-filled recess in the volume of the wiring substrate. A semiconductor component, an electronic component and a method for producing an electronic component are also provided.

Claims

1-15. (canceled)

16. A contact assembly for an electronic component, the contact assembly comprising: a wiring substrate including an upper face, a lower face and a volume having at least one metal-filled recess formed therein; said wiring substrate having at least one contact connection surface provided at least on said upper face, said at least one contact connection surface disposed on said at least one metal-filled recess formed in said volume; and at least one bonding strip connected to said at least one contact connection surface.

17. The contact assembly according to claim 16, which further comprises an electrically insulating layer covering a side of said metal-filled recess disposed opposite to said at least one contact connection surface.

18. The contact assembly according to claim 16, wherein said metal-filled recess tapers into a conical shape and has a greatest diameter directly beneath said at least one contact connection surface.

19. The contact assembly according to claim 18, wherein said metal-filled recess tapers in a longitudinal section.

20. The contact assembly according to claim 16, wherein: said wiring substrate is multi-layered; and said at least one metal-filled recess includes a plurality of metal-filled recesses being interconnected and disposed above one another beneath said at least one contact connection surface in said volume of said wiring substrate.

21. The contact assembly according to claim 16, wherein said at least one metal-filled recess includes a plurality of interconnected, adjacently disposed, metal-filled recesses disposed beneath said at least one contact connection surface in said volume of the wiring substrate.

22. The contact assembly according to claim 16, wherein said at least one metal-filled recess has a metal filling including copper or consisting of copper.

23. The contact assembly according to claim 16, wherein said at least one metal-filled recess has an upper face being at least one of: formed flush with said upper face of said wiring substrate surrounding said at least one metal-filled recess, or covered with a metal layer having said at least one contact connection surface.

24. The contact assembly according to claim 16, which further comprises a laser welded connection interconnecting said bonding strip and said at least one contact connection surface.

25. The contact assembly according to claim 16, wherein said lower face of said wiring substrate is formed of an electrically insulating layer.

26. A semiconductor component, comprising: a contact assembly according to claim 16; and at least one semiconductor part having at least one contact connection surface connected by said at least one bonding strip to said contact connection surface of said wiring substrate disposed on said upper face of said wiring substrate.

27. The semiconductor component according to claim 26, wherein said at least one semiconductor part is a power semiconductor part.

28. An electronic component, comprising: a contact assembly according to claim 16; and at least one further wiring substrate having a contact connection surface connected by said at least one bonding strip to said contact connection surface of said wiring substrate.

29. A method for producing an electronic component according to claim 28, the method comprising: providing a wiring substrate having an upper face, a lower face and a matrix formed of an electrically insulating material and conductor track structures embedded in the electrically insulating material; introducing recesses into the wiring substrate by laser drilling or mechanical drilling from the upper face; introducing a metal filling into the recesses to form metal-filled recesses; applying contact connection surfaces to the upper faces of the metal fillings; and using at least one bonding strip to connect contact connection surfaces of a semiconductor part or a further wiring substrate to the contact connection surfaces.

30. The method according to claim 29, which further comprises forming a multi-layer wiring substrate by successively repeatedly performing the steps of providing the wiring substrate, introducing the recesses into the wiring substrate by laser drilling or mechanical drilling from the upper face, and introducing the metal filling into the recesses.

31. The method according to claim 29, which further comprises using the bonding strip to connect the contact connection surfaces of the semiconductor part or of the further wiring substrate to the contact connection surfaces by laser welding.

Description

[0032] Embodiments of the invention will be described by way of example below with reference to schematic drawings.

[0033] FIG. 1 shows a sectional illustration of a contact assembly as per a first embodiment of the invention;

[0034] FIG. 2 shows a plan view of the contact assembly device as per FIG. 1;

[0035] FIG. 3 shows a sectional view of a contact assembly as per a second embodiment of the invention;

[0036] FIG. 4 shows a sectional view of a contact assembly as per a third embodiment of the invention;

[0037] FIG. 5 shows a sectional view of a contact assembly as per a fourth embodiment of the invention;

[0038] FIG. 6 shows a sectional view of a contact assembly as per a fifth embodiment of the invention; and

[0039] FIGS. 7-11 show steps of a method for producing a contact assembly as per an embodiment of the invention.

[0040] FIG. 1 shows a contact assembly for a semiconductor component, in particular, but not only, for a power semiconductor component, and/or for an electronic component comprising at least two interconnected wiring substrates. The contact assembly 1 comprises a wiring substrate 2 with an upper face 4 and a lower face 6 opposite the upper face 4. At least one contact connection surface 8 is arranged on the upper face 4 of the wiring substrate 2 and is electrically contacted by means of at least one bonding strip 20.

[0041] The contact connection surface 8 is arranged on a metal-filled recess 10 which is formed in the wiring substrate 20. The metal-filled recess 10, in the first embodiment shown in FIG. 1, has a cone shape, wherein the tip 12 of the cone is directed away from the upper face 4 in the direction of the lower face 6, so that the base area of the cone forms part of the upper face 4 of the wiring substrate 2. The contact connection surface 8 is formed on this base area.

[0042] FIG. 2 shows a plan view of the contact assembly 1 as per FIG. 1. In this view, it can be seen that the bonding strips 20, two of which are shown in this view bonded adjacently on the contact connection surface 8, have a relatively large width b.sub.1, b.sub.2. The widths b.sub.1, b.sub.2 are in particular several times greater than a thickness d of the bonding strips 20.

[0043] In this embodiment, the contact connection surface 8 has a rectangular shape. In order to absorb across its entire width the heat that is produced during the bonding process, a plurality of recesses 10 are arranged adjacently beneath the contact connection surface 8. In this way, the heat created when bonding a plurality of adjacently bonded bonding strips, of which also three or more can be provided, can be taken up.

[0044] FIG. 3 shows a contact assembly 1 according to a second embodiment. This differs from the embodiment shown in FIG. 1 in that at least one electrically conductive layer 14 is provided in the wiring substrate 2. In the shown embodiment the electrically conductive layer 14 is not exposed on the lower face 6 of the wiring substrate 2, but instead an electrically insulating material is provided.

[0045] In the embodiment shown in FIG. 3, the metal-filled recess 10 reaches as far as the electrically conductive layer 14 and contacts the latter. In this way, the electrically conductive layer 14 is likewise used to dissipate and spread heat. Depending on the layout of the wiring substrate 2, however, it can also be advantageous to avoid electrical contact between the metal-filled recess 10 and the electrically conductive layer 14. In such a case, the metal-gilled recess 10 ends above the electrically conductive layer 14.

[0046] FIG. 4 shows a contact assembly 1 according to a third embodiment. This differs from the second embodiment shown in FIG. 3 in that the wiring substrate 2 has a plurality of wiring layers 16. In order to be able to dissipate heat particularly efficiently, metal-filled recesses 10 are arranged in each wiring layer 16, more specifically in such a way that the recesses are arranged stacked beneath the contact connection surfaces 8. In this way, heat can be taken up by the contact connection surface 8 and can be dissipated and distributed via a plurality of layers.

[0047] FIG. 5 shows a fourth embodiment of the contact assembly 1, which differs from that shown in FIG. 4 in that the metal-filled recesses 18 are not conical, but cylindrical. Such geometries of metal-filled recesses 18 can be produced in particular by mechanical drilling.

[0048] FIG. 6 shows a contact assembly 1 as per a fifth embodiment of the invention. According to this embodiment, the wiring substrate 2 is formed from a plurality of layers 16, 16′, which each have different metal-filled recesses 10, 18. The metal-filled recesses 10, 18 can be used here both to for electrically contacting and for heat dissipation.

[0049] In the embodiment shown in FIG. 6, metal-filled recesses 10 are exposed at the lower face 6 of the wiring substrate 2. This can be problematic in some circumstances, if the wiring substrate 2 is to be applied directly to a heat sink without contacting this electrically. In this case, an insulating layer can be introduced between the wiring substrate 2 and the heat sink.

[0050] Subjacent recesses 10, 18 in FIGS. 4 to 6 can be filled, as shown, with a metal; they can also be unfilled.

[0051] FIGS. 7-11 show steps of a method for producing a wiring substrate 2 for a contact assembly 1.

[0052] FIG. 7 shows a wiring substrate 2 with an upper face 4 and a lower face 6 arranged opposite, wherein a recess 22 is made in the wiring substrate from the upper face 4. The recess 22 is made by means of laser drilling, which is symbolized by the arrow 24. The method of laser drilling results typically, but not necessarily, in a conical or frustoconical geometry of the recess 22.

[0053] FIG. 8 shows the wiring substrate 2 once a metal filling has been introduced into the recess 22 to form a metal-filled recess 10.

[0054] FIG. 9 shows the wiring substrate 2 once a further layer 2′ has been applied to the upper face 4 of the wiring substrate 2.

[0055] FIG. 10 shows the making of a recess 22 in the further layer 2′ from the upper face 4′ by means of laser drilling. In FIG. 10 an inner contact connection surface 80, or what is known as an inner layer path, is also shown by dashed lines. Inner contact connection surfaces 80 of this kind can also be integrated into the wiring substrate 2.

[0056] FIG. 11 shows the wiring substrate 2, 2′ once a metal contact connection surface 8 has been applied to the metal-filled recesses 10′, 10.

[0057] With the method described with reference to FIGS. 7-11, it is possible to produce multi-layer wiring substrates 2, as are also shown in FIGS. 4-6.