Conductive pins, power modules, ultrasonic welding systems, and methods of using the same
A conductive pin for ultrasonic welding is provided. The conductive pin includes a body portion. The conductive pin also includes a pin head at one end of the body portion. The pin head defines a bonding surface configured to be ultrasonically welded to a workpiece. The bonding surface includes at least one of (i) a nonplanar surface and (ii) an aperture defined in a central region of the bonding surface.
1 . A method of ultrasonically welding a conductive pin to a workpiece, the method comprising steps of:
(a) providing the workpiece; and
(b) ultrasonically welding a bonding surface of the conductive pin to the workpiece to create a welded side of the conductive pin, the conductive pin including a body portion, and a pin head at one end of the body portion, the pin head defining the bonding surface configured to be ultrasonically welded to the workpiece, the bonding surface including a conical aperture defined in a central region of the bonding surface.
2 . The method of claim 1 wherein step (b) includes applying process parameters, using a control system, during the ultrasonic welding based on the bonding surface.
3 . The method of claim 1 wherein the workpiece includes at least one of a power module, a lead frame, and a battery module.
4 . The method of claim 1 wherein step (b) includes applying process parameters, using a control system, during the ultrasonic welding based on the aperture defined in the central region.
5 . The method of claim 1 wherein the bonding surface further includes a nonplanar surface, and step (b) includes applying process parameters, using a control system, during the ultrasonic welding based on the nonplanar surface and the aperture defined in the central region of the nonplanar surface.
6 . The method of claim 1 wherein step (b) includes applying process parameters, using a control system, during the ultrasonic welding, wherein the process parameters include at least one of bonding force, bonding energy, and bonding time.
7 . The method of claim 1 wherein step (b) includes applying process parameters, using a control system, during the ultrasonic welding, wherein the ultrasonic welding utilizes torsional vibration applied by a sonotrode configured to ultrasonically weld the conductive pin to the workpiece.
8 . The method of claim 1 wherein the aperture has a width of 0.1-3 mm.
9 . The method of claim 1 wherein the aperture includes an angle of 60-170 degrees.
10 . The method of claim 1 wherein the aperture includes a depth of 10-1000 μm.
11 . A method of ultrasonically welding a conductive pin to a workpiece, the method comprising steps of:
(a) providing the workpiece; and
(b) ultrasonically welding the conductive pin to the workpiece, the conductive pin including a body portion, and a pin head at one end of the body portion, the pin head defining a bonding surface configured to be ultrasonically welded to the workpiece, the bonding surface including a nonplanar surface, and an aperture defined in a central region of teh bonding surface,
wherein the conductive pin, including the pin head, has a round cross section along its length in a direction from the bonding surface towards the body portion.
12 . The method of claim 11 wherein step (b) includes applying process parameters, using a control system, during the ultrasonic welding based on the bonding surface.
13 . The method of claim 11 wherein step (b) includes applying process parameters, using a control system, during the ultrasonic welding based on the nonplanar surface.
14 . The method of claim 11 wherein step (b) includes applying process parameters, using a control system, during the ultrasonic welding based on the nonplanar surface and the aperture.
15 . The method of claim 11 wherein step (b) includes applying process parameters, using a control system, during the ultrasonic welding, wherein the process parameters include at least one of bonding force, bonding energy, and bonding time.
16 . The method of claim 11 wherein step (b) includes applying process parameters, using a control system, during the ultrasonic welding, wherein the ultrasonic welding utilizes torsional vibration applied by a sonotrode configured to ultrasonically weld the conductive pin to the workpiece.
17 . The method of claim 11 wherein the workpiece includes at least one of a power module, a lead frame, and a battery module.
18 . The method of claim 11 wherein the nonplanar surface includes a curved surface having a radius of curvature of 1-1000 mm.
19 . The method of claim 11 wherein the nonplanar surface includes a curved surface having a radius of curvature of 2-100 mm.