SEMICONDUCTOR MODULE COMPRISING A SEMICONDUCTOR AND COMPRISING A SHAPED METAL BODY THAT IS ELECTRICALLY CONTACTED BY THE SEMICONDUCTOR

Abstract

Semiconductor module including a semiconductor and including a shaped metal body that is electrically contacted by the semiconductor, for forming a contact surface for an electrical conductor, wherein the shaped metal body is bent or folded. A method is also described for establishing electrical contacting of an electrical conductor on a semiconductor, said method including the steps of: fastening a bent or folded shaped metal body of a constant thickness to the semiconductor by means of a first fastening method and then fastening the electrical conductor to the shaped metal body by means of a second fastening method.

Claims

1. A semiconductor module comprising a semiconductor and comprising a shaped metal body that is electrically contacted by the semiconductor, for forming a contact surface for an electrical conductor, wherein the shaped metal body is bent or folded.

2. The semiconductor module according to claim 1, wherein the shaped metal body is bent multiple times or folded multiple times.

3. The semiconductor module according to claim 1, wherein the shaped metal body is corrugated.

4. The semiconductor module according to claim 1, wherein the shaped metal body consists of aluminum (Al) or copper (Cu).

5. The semiconductor module according to claim 1, wherein the shaped metal body is connected to the semiconductor by means of sintering.

6. The semiconductor module according to claim 1, wherein the shaped metal body is connected to the semiconductor by means of adhesive bonding.

7. The semiconductor module according to claim 1, wherein the shaped metal body is connected to the semiconductor by means of soldering.

8. The semiconductor module according to claim 1, wherein the shaped metal body is connected to the semiconductor by means of nanowires.

9. The semiconductor module according to claim 1, wherein the electrical conductor is a lead frame or a ribbon.

10. The semiconductor module according to claim 1, wherein the semiconductor is produced from silicon carbide (SiC), at least in part.

11. A method for establishing electrical contacting of an electrical conductor on a semiconductor, said method comprising the steps of: fastening a bent or folded shaped metal body of a constant thickness to the semiconductor by means of a first fastening method, fastening the electrical conductor to the shaped metal body by means of a second fastening method.

12. A method according to claim 11, wherein the first fastening method is sintering.

13. The method according to claim 11, wherein the first fastening method is by means of nanowires.

14. The method according to claim 11, wherein the second fastening method is thermosonic bonding or ultrasonic bonding.

15. The method according to claim 11, wherein the second fastening method is by means of nanowires.

16. The method according to claim 11, wherein the electrical conductor is a lead frame or a ribbon.

17. The method according to claim 11, wherein the semiconductor is produced from silicon carbide (SiC), at least in part.

18. The semiconductor module according to claim 2, wherein the shaped metal body is corrugated.

19. The semiconductor module according to claim 2, wherein the shaped metal body consists of aluminum (Al) or copper (Cu).

20. The semiconductor module according to claim 3, wherein the shaped metal body consists of aluminum (Al) or copper (Cu).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The invention will be explained in greater detail in the following, with reference to a particularly preferred embodiment shown in the accompanying drawings. In the drawings:

[0045] FIG. 1 is a perspective detail view of a particularly preferred embodiment of a semiconductor module according to the invention;

[0046] FIG. 2 is a side view of differently designed shaped metal body according to preferred embodiments;

[0047] FIG. 3 is a schematic view illustrating the fastening of an electrical conductor to the shaped metal body formed according to the invention, by means of ultrasonic welding;

[0048] FIG. 4 is a schematic view illustrating the fastening of an electrical conductor to the shaped metal body formed according to the invention, by means of laser welding; and

[0049] FIG. 5 is a flow chart illustrating the inventive method for establishing electrical contacting of an electrical conductor on a semiconductor.

DETAILED DESCRIPTION

[0050] FIG. 1 is a perspective detail view of a particularly preferred embodiment of a semiconductor module according to the invention.

[0051] The semiconductor module 100 comprises a semiconductor 10 that is arranged on a substrate 20. A shaped metal body 30 which forms a contact surface for an electrical conductor 40 is arranged on the upper face of the semiconductor 10. In the example shown, the shaped metal body 30 is electrically conductively connected to the semiconductor 10 over the entire surface, by means of a connection layer 50, in particular a sintered layer. The semiconductor 10 and the shaped metal body 30 can be connected in a conventional manner, by means of sintering.

[0052] Alternatively, the semiconductor 10 and the shaped metal body 30 can be connected using electrically conducting nanowires. Such nanowires are grown from one or more of the surfaces to be connected, and then the surfaces are brought together. The joining takes place under compression and possibly with a raised temperature. However, the technique is admirably suited to the current invention, since it can successfully be used with relatively low pressures, thus enabling the connection of components utilizing the shaped metal body 30 without damaging the elastic properties of the shaped metal body 30. The pressure used for bonding may be up to 70 MPa, but in some situations it may be as low as 1 MPa. The nanowires 10 may typically comprise copper or gold, nickel, silver, platinum, or other suitable metals. Typically they may have a diameter of between 30 nm and 2 μm and have a length of between 500 nm and 50 μm. A potential great advantage of the use of nanowires, is that the joint formed is flexible, and thus the stresses around the items being joined, such as a semiconductor chip or a substrate, is reduced. This in turn leads to much improved reliability and module life.

[0053] In this case, the shaped metal body 30 is elasticity elastically deformable in the X- or Y- and in the Z-direction and has a sufficient surface area for establishing electrical contact. In this case, the shaped metal body comprises a corrugated structure extending in the y-direction, as a result of which the shaped metal body also extends in the Z-direction.

[0054] FIG. 2 is a side view of differently designed shaped metal bodies 30 according to preferred embodiments. Metal shaped bodies that are designed in a preferred manner have a wavelike appearance similar to the designation of vibration modes of signals from the side or in cross section, in particular as a sine wave (a), a square wave (b) or a triangular wave (c). Alternatively, the shaped metal body 30 may also be formed in a manner similar to a sawtooth wave (not shown) in cross section.

[0055] FIG. 3 is a schematic view illustrating the fastening of an electrical conductor to the shaped metal body formed according to the invention, by means of ultrasonic welding.

[0056] In particular, FIG. 3 shows a semiconductor module 100 comprising a semiconductor 10 that is arranged on a substrate 20 and carries a shaped metal body 30, designed in a particularly preferred manner, on the upper face thereof. The shaped metal body 30 is used to form a contact surface for an electrical conductor 40 which, in the example shown, is intended to be connected to the shaped metal body 30 by means of ultrasonic welding. In this case, the corrugated shaped metal body 30 functions as a buffer zone for mechanical stress caused by the ultrasonic welding UW process. This stress acts in the direction of the semiconductor 10, and can be absorbed by deformations in the shaped metal body 30, thus protecting the semiconductor 10.

[0057] As an alternative, FIG. 4 is a schematic view illustrating the fastening of an electrical conductor to the shaped metal body formed according to the invention, by means of laser welding L. In the same structure of the semiconductor module 100, the shaped metal body 30 functions in this case as a thermal buffer zone in which the heat introduced by the laser welding can be dissipated without damaging the semiconductor 10.

[0058] FIG. 5 is a flow chart illustrating the inventive method 200 for establishing electrical contacting of an electrical conductor on a semiconductor. The said method 200 comprises the steps of: [0059] 1. fastening 201 a bent or folded shaped metal body of a constant thickness to the semiconductor by means of a first fastening method, and [0060] 2. fastening 202 the electrical conductor to the shaped metal body by means of a second fastening method.

[0061] While the present disclosure has been illustrated and described with respect to a particular embodiment thereof, it should be appreciated by those of ordinary skill in the art that various modifications to this disclosure may be made without departing from the spirit and scope of the present disclosure.