Sonotrodes for ultrasonic welding of a conductive pin to a workpiece, ultrasonic welding systems

Abstract

A sonotrode for welding a conductive pin to a workpiece using ultrasound, wherein the sonotrode comprises: a hull section designed to be coupled with an ultrasonic transducer, wherein the body section terminates at a tip section, the tip section defining an joining element designed to be joined with a corresponding joining element of a base section of the conductive pin, wherein the conductive pin is aligned in a predetermined configuration by joining the joining element defined by the tip section with the corresponding joining element of the base section.

Description

REFERENCE TO LINKED REGISTRATION

[0001] This application claims the legal benefit of preliminary US application No. 63 / 725093, filed on November 26, 2024, the contents of which are hereby incorporated by reference. SPECIALIZATION

[0002] The invention relates to ultrasonic welding and in particular to improved sonotrodes for use in ultrasonic welding systems, such as ultrasonic welding systems for welding conductive pins. BACKGROUND

[0003] Ultrasonic welding is a technology used to join conductive components. In ultrasonic welding, an ultrasonic transducer (e.g., with a sonotrode) can be used to convert electrical energy into mechanical motion / friction (e.g., linear motion / friction, torsional motion / friction, etc.). U.S. Patents No. 10,882,134 and No. 11,364,565 (each entitled "ULTRASONIC WELDING SYSTEMS AND METHOD FOR THEIR USE"), granted to Kulicke and Soffa Industries, Inc., relate to improvements in ultrasonic welding technology and are incorporated herein by reference in their entirety.

[0004] One specific application of ultrasonic welding technology relates to the ultrasonic welding of pins (where such pins are conventionally soldered and / or pressed into power modules). U.S. Patent No. 11,285,561 (titled "ULTRASOUND WELDING SYSTEMS AND METHOD FOR THEIR USE"), U.S. Patent No. 11,504,800 (titled "ULTRASOUND WELDING SYSTEMS AND METHOD FOR THEIR USE"), U.S. Patent No. 11,958,124 (titled "ULTRASOUND WELDING SYSTEMS AND METHOD FOR THEIR USE"), U.S. Patent No. 11,850,676 (titled "ULTRASOUND WELDING SYSTEMS, METHOD FOR THEIR USE AND WORKFOLIOS CONNECTED THERE, INCLUDING WELDED CONDUCTIVE PINS"), U.S. Patent No. 12,070,814 (titled “ULTRASONIC WELDING SYSTEMS, METHOD FOR THEIR USE AND WORKPIECES RELATING TO WELDED CONDUCTIVE PINS”, US Patent No. 12,377.489 (titled "Ultrasonic Welding Systems, Methods for Their Use and Associated Workpieces Relating to Welded Conductive Pins"), US Patent No. 12,370,620 (titled "ULTRASOUND WELDING SYSTEMS FOR CONDUCTIVE PINS AND ASSOCIATED METHOD"), US Patent Application No. 2025 / 0332654 (titled "ULTRASOUND WELDING SYSTEMS FOR CONDUCTIVE PINS AND ASSOCIATED METHOD"), US Patent Application No. 2025 / 0187103 (titled "CONDUCTIVE PINS, POWER MODULES, ULTRASOUND WELDING SYSTEMS AND METHOD FOR THEIR USE"), International Patent Application No. WO 2024 / 220203 (titled “ULTRASONIC WELDING SYSTEMS, SONOTRODES AND CONDUCTIVE PINS FOR SUCH SYSTEMS AND RELATED PROCESSES AND WORKPIECES”), and US Patent Application No. 2025 / 0289074 (“ULTRASONIC WELDING SYSTEMS AND SONOTRODES FOR ULTRASONIC WELDING SYSTEMS”), which each individual Kulicke and Soffa Industries, Inc.The assigned tasks relate to improvements in ultrasonic welding technology with respect to conductive pins and are also included in their entirety by reference.

[0005] In practice, a sonotrode can be used to hold a conductive pin in place before ultrasonic welding of the conductive pin to a workpiece. During holding and / or ultrasonic welding, a conductive pin may be misaligned and / or misoriented relative to the sonotrode. Therefore, it would be desirable to provide improved sonotrodes and ultrasonic welding systems that incorporate such sonotrodes, specifically designed for use in conjunction with ultrasonic welding of pins. SUMMARY

[0006] According to an exemplary embodiment of the invention, a sonotrode is provided for welding a conductive pin to a workpiece using ultrasound. The sonotrode comprises a body section designed to be coupled to an ultrasonic transducer. The body section terminates at a tip section, the tip section defining a joining element designed to be joined with a corresponding joining element of a base section of the conductive pin. The conductive pin is aligned by joining the joining element defined by the tip section with the corresponding joining element of the base section.

[0007] According to a further exemplary embodiment of the invention, an ultrasonic welding system is provided. The ultrasonic welding system comprises a support structure designed to hold a workpiece and a welding head assembly. The welding head assembly includes an ultrasonic transducer and a sonotrode supported by the ultrasonic transducer. The sonotrode comprises a tip section, the tip section defining an joining element designed to be joined with a corresponding joining element of a base section of the conductive pin. The conductive pin is aligned in a predetermined configuration by joining the joining element defined by the tip section with the corresponding joining element of the base section.

[0008] According to other embodiments of the invention, the sonotrode and / or the ultrasonic welding system described in the two immediately preceding paragraphs may have one or more of the following features: the joining element defined by the tip section comprises an opening designed to be joined with a form of the corresponding joining element of the base section; the conductive pin defines a hole at a location along its length, the predetermined configuration relating to the orientation of the hole; the conductive pin is an "L"-shaped conductive pin, the predetermined configuration relating to the orientation of the "L"-shaped conductive pin; the conductive pin is a power connector designed for ultrasonic welding in a power module; the sonotrode is designed to weld the conductive pin to a workpiece using a linear motion;The joining element defined by the tip section comprises a chamfered section designed to guide the conductive pin into a position aligned with the sonotrode; and the sonotrode is designed to weld the conductive pin to a workpiece using a torsional motion.

[0009] According to a further exemplary embodiment of the invention, a sonotrode is provided for ultrasonic welding of a conductive pin to a workpiece. The sonotrode comprises a body section designed to be coupled to an ultrasonic transducer. The body section terminates in a tip section. The tip section is designed to receive the conductive pin. The sonotrode also comprises an alignment mechanism designed to align the conductive pin within an opening of the sonotrode.

[0010] According to a further exemplary embodiment of the invention, an ultrasonic welding system is provided. The ultrasonic welding system comprises a support structure designed to hold a workpiece. The ultrasonic welding system also comprises a welding head assembly with an ultrasonic transducer. The ultrasonic welding system further comprises a sonotrode supported by the ultrasonic transducer. The sonotrode includes a tip section. The tip section is designed to receive a conductive pin. The sonotrode also includes an alignment mechanism designed to align the conductive pin within an opening of the sonotrode.

[0011] According to other embodiments of the invention, the sonotrode and / or the ultrasonic welding system described in the two immediately preceding paragraphs may have one or more of the following features: The alignment mechanism comprises a first alignment tool for aligning the conductive pin; the alignment mechanism comprises a second alignment tool for aligning the conductive pin, the first alignment tool being arranged adjacent to a first lateral opening of the sonotrode, the second alignment tool being arranged adjacent to a second lateral opening of the sonotrode; the first alignment tool and the second alignment tool being designed to be supplied with ultrasonic energy during a pin alignment process; the first alignment tool and the second alignment tool being designed to vibrate during a pin alignment process;The first alignment tool and the second alignment tool are spring-based alignment tools; the alignment mechanism is an alignment tool arranged within the opening of the sonotrode, wherein the alignment tool defines an alignment opening designed to receive an upper tip of the conductive pin; and the conductive pin defines a hole at a location along its length, wherein the alignment mechanism aligns the conductive pin within the opening by engaging the hole.

[0012] An unclaimed method for operating an ultrasonic welding system comprises the following steps: (a) providing a conductive pin for a sonotrode of the ultrasonic welding system, the sonotrode comprising a body section terminating at a tip section, the tip section defining an joining element designed to be joined with a corresponding joining element of a base section of the conductive pin; and (b) aligning the conductive pin in a predetermined configuration with respect to the sonotrode by joining the joining element defined by the tip section with the corresponding joining element of the base section.

[0013] The unclaimed method for operating an ultrasonic welding system described in the immediately preceding paragraph may have one or more of the following features: Step (a) comprises picking up the conductive pin using the sonotrode; the sonotrode picks up the conductive pin using a vacuum source; Step (b) comprises using a vacuum source coupled to the sonotrode, wherein the vacuum source assists in aligning the conductive pin in the predetermined configuration; it further comprises a step (c) of ultrasonic welding the conductive pin to a workpiece according to step (b); Step (c) comprises using torsion welding to ultrasonic welding the conductive pin to the workpiece; wherein Step (c) comprises using linear welding to ultrasonic welding the conductive pin to the workpiece;The joining element defined by the tip section includes an opening designed to be joined with a form of the corresponding joining element of the base section; the conductive pin defines a hole along its length, which relates to the orientation of the hole; the conductive pin is an "L"-shaped conductive pin, the predetermined configuration relating to the orientation of the "L"-shaped conductive pin; the conductive pin is a power terminal designed for ultrasonic welding in a power module; and the joining element defined by the tip section includes a chamfered section designed to guide the conductive pin into an aligned position with respect to the sonotrode.

[0014] Another unclaimed method for operating an ultrasonic welding system comprises the following steps: (a) providing a conductive pin for a sonotrode of the ultrasonic welding system, the sonotrode comprising a body section terminating at a tip section, the tip section receiving the conductive pin; and (b) aligning the conductive pin within an opening of the sonotrode at the tip section using an alignment mechanism.

[0015] The unclaimed method for functionalizing an ultrasonic welding system described in the immediately preceding paragraph may have one or more of the following features: Step (a) comprises picking up the conductive pin using the sonotrode; the sonotrode picks up the conductive pin using a vacuum source; it further comprises a step (c) of ultrasonic welding the conductive pin to a workpiece according to step (b); step (c) comprises using torsion welding to ultrasonic welding the conductive pin to the workpiece; wherein step (c) comprises using linear welding to ultrasonic welding the conductive pin to the workpiece; the alignment mechanism comprises a first alignment tool for aligning the conductive pin;The alignment mechanism comprises a second alignment tool for aligning the conductive pin; the first alignment tool is arranged adjacent to a first lateral opening of the sonotrode; the second alignment tool is arranged adjacent to a second lateral opening of the sonotrode; the first alignment tool and the second alignment tool are designed to be supplied with ultrasonic energy during a pin alignment process; the first alignment tool and the second alignment tool are designed to vibrate during a pin alignment process; the first alignment tool and the second alignment tool are spring-based alignment tools;The alignment mechanism is an alignment tool arranged within the opening of the sonotrode, wherein the alignment tool defines an alignment opening designed to receive an upper tip of the conductive pin; the conductive pin defines a hole along its length, and step (b) comprises aligning the conductive pin within the opening of the sonotrode such that the hole is arranged in a predetermined configuration; and the conductive pin is an "L"-shaped conductive pin, wherein step (b) comprises aligning the conductive pin within the opening such that the "L"-shaped conductive pin is arranged in a predetermined configuration. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The invention is best understood with reference to the following detailed description in conjunction with the accompanying drawings. It is emphasized that, in accordance with common practice, the various features in the drawings are not to scale. On the contrary, the dimensions of the various features have been arbitrarily enlarged or reduced for clarity. The drawings include the following figures: Fig. Figure 1 is a block diagram of an ultrasonic welding system according to various exemplary embodiments of the invention; Fig. Figures 2A-2F are side views in cross-section and top views of a sonotrode with an alignment mechanism and a conductive pin according to an exemplary embodiment of the invention; Fig. Figures 3A-3B are side views in cross-section of another sonotrode with an alignment mechanism and the conductive pin made of Fig. 2A-2F according to a further exemplary embodiment of the invention; Fig. 4 is a side view in cross-section of the sonotrode made of Fig. 2A-2F and the conductive pin made of Fig. 2A-2F according to a further exemplary embodiment of the invention; Fig. 5A is a side view in cross-section of another sonotrode with an alignment mechanism and the conductive pin made of Fig. 2A-2F according to a further exemplary embodiment of the invention; Fig. 5B is a bottom view of the sonotrode made of Fig. 5A; Fig. 5C is a top view of the conductive pin made of Fig. 5A in conjunction with part of the sonotrode made of Fig. 5A; Fig. Figure 6A is a side view in cross-section of another sonotrode and another conductive pin according to a further exemplary embodiment of the invention; Fig. 6B is a view of the sonotrode from Fig. 6A from the bottom; Fig. 6C is a top view of the conductive pin made of Fig. 6A; Fig. Figure 7A is a side view in cross-section of another sonotrode and another conductive pin according to a further exemplary embodiment of the invention; Fig. 7B is a bottom view of the sonotrode from Fig. 7A; Fig. 7C is a top view of the conductive pin made of Fig. 7A; Fig. Figures 8A-8B are side views in cross-section of another sonotrode and another conductive pin according to a further exemplary embodiment of the invention; Fig. 8C-8D are top views of the conductive pin made of Fig. 8A-8B; Fig. 8E is a bottom view of the sonotrode from Fig. 8A-8B; Fig. Figures 9A-9B are side views in cross-section of another sonotrode and another conductive pin according to a further exemplary embodiment of the invention; Fig. 9C-9D are top views of the conductive pin made of Fig. 9A-9B; Fig. 9E is a view of the sonotrode from Fig. 9A-9B from the bottom; Fig. Figure 10A is a side view in cross-section of another sonotrode and another conductive pin according to a further exemplary embodiment of the invention; Fig. 10B is a bottom view of the sonotrode made of Fig. 10A; Fig. 10C is a top view of the conductive pin made of Fig. 10A; and Fig. Figures 11-12 are flowcharts of various unclaimed methods for operating an ultrasonic welding system according to various exemplary embodiments of the invention. DETAILED DESCRIPTION

[0017] Certain conductive pins are desirablely welded to a workpiece in a predetermined configuration. For example, conductive pins that define a "hole" along their length (sometimes called "fisheye" pins) are sometimes welded to a workpiece. Such fisheye pins can be used for proper soldering after the assembly of a power module. These fisheye pins can be pressed into a fixture on a printed circuit board. Therefore, the configuration of the conductive pin is important when welding it to a workpiece.

[0018] In the case of fisheye pins and / or other conductive pins where the orientation of the conductive pin (e.g., a "directional" conductive pin) is relevant, certain embodiments of the present invention provide sonotrodes that correctly orient / align the conductive pins during (and / or after) the conductive pin is picked up by the sonotrode. Accordingly, the orientation, alignment, and / or directional dependence (e.g., in an XY plane of an ultrasonic welding system) of the conductive pin can be provided during ultrasonic welding of the conductive pin to a workpiece.

[0019] Referring to the drawings, shows Fig. 1. An ultrasonic welding system 100. The ultrasonic welding system 100 comprises an infeed workpiece feeder 102 for providing a workpiece 102a1, wherein the infeed workpiece feeder 102 can be designed to carry a variety of workpieces 102a1 (e.g., the infeed workpiece feeder 102 can be a carrier, such as a handling system for magazines for carrying a variety of workpieces 102a1, or other feeder structures suitable for the application-specific workpiece, etc.). Exemplary workpieces 102a1 carried by the infeed workpiece feeder 102 include power modules, components of power modules, ladder frames, battery modules, etc.The workpieces 102a1 are fed from the input workpiece feeder 102 to the material handling system 104 (by any desired transport device, which may be included in a material handling system 104, such as a gripper device). The material handling system 104 moves the workpiece 102a1 (e.g., using a conveyor device, a gripper device, etc.) from the input workpiece feeder 102 to a support structure 106. The support structure 106 holds the workpiece (e.g., workpiece 102a1, a clamped workpiece 102a2, etc.) during a welding process. After the welding process (which is described below in relation to a welding head assembly 112), a now welded workpiece 102a3 (e.g. using a conveying device, a gripping device, etc.) is moved from a section of the material handling system 104 downstream of the support structure 106 to an output workpiece supply 110.The output workpiece supply 110 is designed to receive welded workpieces 102a3 after processing by the welding head assembly 112. The output workpiece supply 110 can be a carrier, for example a handling system for magazines for transporting a large number of welded workpieces 102a3, or another feeding structure suitable for the application-specific workpiece.

[0020] The ultrasonic welding system 100 comprises a welding head assembly 112. The welding head assembly 112 includes an ultrasonic transducer 112b, which carries a sonotrode 116 (e.g., sonotrode 216, sonotrode 216', sonotrode 516, sonotrode 616, sonotrode 716, sonotrode 816, sonotrode 916, sonotrode 1016) and is movable along a variety of essentially horizontal axes (e.g., X-axis, Y-axis, etc.). The sonotrode 116 comprises a body section 116a, which terminates at a tip section 116b (e.g. tip section 216b, tip section 516b, tip section 616b, tip section 716b, tip section 816b, tip section 916b, tip section 1016b).

[0021] In the Fig. In the example shown in Figure 1, the welding head assembly 112 is designed to move along the X-axis and the Y-axis of the ultrasonic welding system 100. In the example shown in Figure 1, the welding head assembly 112 is designed to move along the X-axis and the Y-axis of the ultrasonic welding system 100. Fig. In the example shown, the welding head assembly 112 is also designed to move along the Z-axis of the ultrasonic welding system 100 and around a theta-axis (Ø-axis) of the ultrasonic welding system 100. Not all of these axes of movement are required in every application. Using the axes of movement of the welding head assembly 112, the sonotrode 116 can be moved into the correct welding positions relative to the clamped workpiece 102a2 (clamps not shown).A camera 114 of the ultrasonic welding system 100 is also provided (whereby the camera can optionally be carried by the welding head assembly 112 or by another part of the ultrasonic welding system 100) for imaging operations relating to the alignment between the sonotrode 116 and the clamped workpiece 102a2, the alignment of the components of the clamped workpiece 102a2 itself, the optical inspection of the welds after the welding process, etc.

[0022] The ultrasonic welding system 100 (or other systems within the scope of the invention) can be used to weld various types of workpieces. Examples of workpieces include a power module, a ladder frame, and a battery module.

[0023] According to the invention, various types of ultrasonic movements can be transmitted to a conductor (e.g., a conductive pin, a signal connector, a conductive terminal, a power terminal, etc.). For example, the sonotrode can be designed to weld a conductor to a workpiece using at least one linear ultrasonic movement and / or one torsional ultrasonic movement.

[0024] Certain of these workpieces are designed to receive a conductive pin. The term "conductive pin" here refers to a conductive structure intended to be welded to a workpiece. The conductive pin may have a free end (after welding to a workpiece), and a body section of the conductive pin may extend substantially vertically from a "welded" end to the free end. The cross-section of the conductive pin may be round, square, rectangular, or any other shape. The conductive pins described here may include, among others, "L-shaped" pins or "fisheye" pins. The term "conductive pin" also encompasses conductive receptacles or sleeves (e.g., in a tubular form), where the conductive receptacle / sleeve is ultrasonically welded to a workpiece and designed to receive another conductive element.In certain embodiments, the conductive pin can be a power terminal designed for ultrasonic welding in a power module.

[0025] According to certain exemplary embodiments of the invention, the ultrasonic welding system 100 comprises a conductive pin feeder 108 designed to provide a plurality of conductive pins 208 (although conductive pins 208 are shown, the conductive pin feeder 108 can include any pins within the scope of the invention, such as conductive pin 608, conductive pin 708, conductive pin 808, conductive pin 908, and conductive pin 1008) for welding using the sonotrode 116. Exemplary configurations for the conductive pin feeder include: a grid arrangement (including columns and rows of conductive pins aligned to facilitate intake), a tray feeder, a hopper, a coil, etc. Alternative configurations are conceivable.The feeder for conductive pins 108 can be designed to operate with a buffer system so that the pins are guided through a staging area and are ready to be picked up for welding.

[0026] The ultrasonic welding system 100, including the conductive pin feeder 108 and the sonotrode 116, can take various forms. More precisely, different configurations of the conductive pin feeder 108, different configurations of the sonotrode 116, etc., are conceivable. Exemplary configurations are shown and described here.

[0027] With reference to the Fig. Figure 2A-2F shows a sonotrode 216 for ultrasonic welding of a conductive pin 208 to a workpiece. The sonotrode 216 comprises a body section (see, for example, body section 116a in Figure 2A-2F). Fig. 1), which is designed to be coupled to the ultrasonic transducer 112b. The body section of the sonotrode 216 terminates at a tip section 216b. The tip section 216b is designed to receive the conductive pin 208. For example, the tip section 216b defines an opening 216b1 for receiving the conductive pin 208. The tip section 216b defines a working surface 216b2 for interacting with a base section 208a of the conductive pin 208.

[0028] The tip section 216b is shown with a lateral opening 216b3 and a lateral opening 216b4. The lateral opening 216b3 and the lateral opening 216b4 are designed to allow alignment tools (e.g., alignment needles) of an alignment mechanism to be arranged within the lateral opening 216b3 and the lateral opening 216b4 in order to align the conductive pin 208 within the opening 216b1 of the sonotrode 216.

[0029] The conductive pin 208 is shown arranged inside the sonotrode 216 (e.g., using the vacuum of a vacuum source) such that a surface of the base section 208a contacts the working surface 216b2 of the sonotrode 216. The conductive pin 208 comprises a base section 208a connected to an elongated section 208b. The conductive pin 208 defines a hole 208c1 at a location along its length. In the Fig. In the example shown in Figure 2A, the hole 208c1 is defined by an upper tip 208c of the conductive pin 208.

[0030] With reference to Fig. Figure 2B shows a top view of the conductive pin 208 (with the sonotrode 216 not shown for clarity).

[0031] With reference to the Fig. Figure 2C-2D shows an alignment mechanism 218 of the sonotrode 216. The alignment mechanism 218 is designed to align the conductive pin 208 within the opening 216b1 by engaging with the hole 208c1 (and / or the tip section 208c). The alignment mechanism 218 comprises an alignment tool 218a and an alignment tool 218b for aligning the conductive pin 208. The alignment tool 218a is located within the lateral opening 216b3 of the sonotrode 216. The alignment tool 218b is located within the lateral opening 216b4 of the sonotrode 216.

[0032] As shown, the alignment tool 218a and the alignment tool 218b are brought into contact with the tip section 208c of the conductive pin 208. In certain embodiments, the alignment tool 218a and the alignment tool 218b are designed to be supplied with ultrasonic energy (e.g., ultrasound from the ultrasonic transducer 112b). In certain embodiments, the alignment tool 218a and the alignment tool 218b are designed to vibrate during a pin alignment process (e.g., using a piezoelectric stack actuator).

[0033] With reference to the Fig. Figures 2E-2F show the alignment mechanism 218 of the sonotrode 216, which pushes through the hole 208c1 of the conductive pin 208, thereby rotating the conductive pin 208 (e.g., by ~90°), aligning, and adjusting it. Accordingly, it is shown that the sonotrode 216 and / or the alignment mechanism 218 align the conductive pin 208 in a desired (e.g., predetermined) orientation.

[0034] With reference to the Fig. Figures 3A-3B show a sonotrode 216'. The sonotrode 216' is essentially identical to the sonotrode 216, except that instead of the alignment mechanism 218 of the sonotrode 216, an alignment mechanism 218' is provided. Repeated reference numerals have been omitted, and certain reference numerals relating to Fig. References to 1 have been added for clarification. The alignment mechanism 218' comprises a spring-based alignment tool 218'a and a spring-based alignment tool 218'b (e.g., using a leaf spring). With particular reference to Fig. 3A The spring-based alignment tool 218'a and the spring-based alignment tool 218'b are compressed / bent together if the conductive pin 208 is not aligned. With particular reference to Fig. 3B The spring-based alignment tool 218'a and the spring-based alignment tool 218'b are relaxed / straightened when the conductive pin 208 is rotated, aligned and oriented.

[0035] With reference to Fig. Figure 4 shows the sonotrode 216, which is used in conjunction with an alignment mechanism 218''. The alignment mechanism 218'' is essentially the same as the alignment mechanism 218' from Fig. 3A-3B, except that the alignment mechanism 218' is not entirely supported by the sonotrode; instead, the alignment mechanism 218'' (including a spring-based alignment tool 218''a and a spring-based alignment tool 218''b) is supported by the ultrasonic transducer 112b of the welding head assembly 112. Thus, it is clear that alignment mechanisms within the scope of the invention can be supported by any part of the welding head assembly 112. Repeated reference numerals have been omitted, and certain reference numerals relating to Fig. The reference to 1 was added for clarification.

[0036] Further exemplary aspects (and uses) of alignment tools (e.g., alignment needles) that are used in conjunction with the Fig. The processes shown and described in Figures 2A-2F, 3A-3B, and 4 can be described as follows. After a conductive pin has been inserted into the sonotrode (e.g., by vacuum), the alignment tools (e.g., alignment needles) can be pressed against a portion of the conductive pin that defines the hole (the "fisheye"). Energy (e.g., ultrasonic energy, vibration, etc.) can be applied to the sonotrode to properly align the conductive pin with the alignment tools (e.g., alignment needles). Once the conductive pin is properly aligned, it is welded to a workpiece. The sonotrode can then be raised (e.g., after releasing the alignment tools) to receive another conductive pin. The alignment tools can be released before or after the ultrasonic welding of the conductive pin to the workpiece.Alignment needles must not touch the sonotrode during operation and may have rounded tips to assist in the alignment of a conductive pin and to avoid excessive wear.

[0037] The alignment tools (e.g., alignment needles) can be actuated by electric, pneumatic, air, piezoelectric, magnetic, electric motor, or any other device suitable for the process. The alignment tools (e.g., alignment needles) can be made of a hard and durable engineering material, metal, ceramic, or a combination such as tungsten carbide. The alignment tools (e.g., alignment needles) can have a durable coating or a special tip section made of a different material than the rest of the alignment tool.

[0038] Although the drawings use two different alignment tools in each of the Fig. As shown in Figures 2A-2F, 3A-3B and 4, the invention is not limited thereto. A single alignment tool or more than two alignment tools are conceivable.

[0039] In certain embodiments, the alignment tools (e.g., alignment tool 218a, alignment tool 218b, alignment tool 218'a, alignment tool 218'b, alignment tool 218'‚a, alignment tool 218''b) of the alignment mechanisms (e.g., alignment mechanism 218, alignment mechanism 218', alignment mechanism 218'') can be supplied using an ultrasonic transducer 112b to assist in the alignment / rotation of the conductive pin 208 (e.g., to assist in the connection of the alignment tool and the hole 208c1 of the upper tip 208c of the conductive pin 208, to overcome friction due to misalignment, etc.).

[0040] With reference to Fig. Figure 5A shows a sonotrode 516 for ultrasonic welding of the conductive pin 208 to a workpiece. The sonotrode 516 comprises a body section (see, for example, body section 116a in Figure 5A). Fig. 1), which is designed to be coupled to the ultrasonic transducer 112b. The body section of the sonotrode 516 terminates at a tip section 516b. The tip section 516b is designed to receive the conductive pin 208. For example, the tip section 516b defines an opening 516b1 for receiving the conductive pin 208. The opening 516b1 can have more than one diameter along the length of the sonotrode 516 to receive various elements (e.g., the conductive pin 208, an alignment mechanism, an alignment tool, etc.). In the illustrated embodiment, the opening 516b1 comprises: a first diameter designed to receive a conductive pin (e.g., the conductive pin 208); and a second diameter designed to receive part of an alignment mechanism (e.g., alignment tool 518a).The tip section 516b defines a working surface 516b2 for interaction with the base section 208a of the conductive pin 208.

[0041] The sonotrode 516 includes an alignment mechanism 518. The alignment mechanism 518 includes an alignment tool 518a for aligning the conductive pin 208. The alignment tool 518a is located within the opening 516b1 of the sonotrode 516. The alignment tool 518a defines an alignment opening 518b (e.g., a gap, a space, an opening, etc., as shown in Fig. 5C shown), which is designed to accommodate the upper tip 208c of the conductive pin 208.

[0042] With reference to Fig. Figure 5B shows a bottom view of sonotrode 516. (With reference to...) Fig. Figure 5C shows a top view of the conductive pin 208 interacting with part of the alignment tool 518a.

[0043] When the conductive pin 208 is provided to the sonotrode 516 (e.g., the sonotrode 516 picks up the conductive pin 208 using a vacuum source), the alignment tool 518a interacts with an upper section (e.g., the upper tip 208c) of the conductive pin 208, such that the conductive pin 208 is aligned in a predetermined configuration. In the illustrated embodiment, the alignment tool 518a comprises a first flange section 518a1 and a second flange section 518a2. The first flange section 518a1 and the second flange section 518a2 are arranged on opposite sides of the conductive pin 208 in order to align the conductive pin 208 (e.g., at least one section of the conductive pin 208, such as the upper tip 208c, can be described as being ‘clamped’ between the first flange section 518a1 and the second flange section 518a2).In certain embodiments, ultrasonic energy can be delivered to the alignment tool 518a using an ultrasonic transducer 112b to assist in the alignment / rotation of the conductive pin 208 (e.g., to assist in the connection between the alignment tool 518a and the upper tip 208c of the conductive pin 208, to overcome friction due to misalignment, etc.).

[0044] Certain embodiments of the invention relate to joining elements of a tip section of a sonotrode that interact with a corresponding joining element of a base section of a conductive pin. As used herein, “joining element” refers to a shape, structure, or feature designed to align a conductive pin in a predetermined configuration. For example, the predetermined configuration may refer to the arrangement of the “hole” of a fisheye pin such that it points in a predetermined direction (e.g., is angled in that direction). In another example, the predetermined configuration may refer to the arrangement of an “L”-shaped pin such that it points in a predetermined direction (e.g., is angled in that direction).

[0045] Although various designs exist, which are described in the Fig. Figures 6A-6C, 7A-7C, 8A-8E, 9A-9E and / or 10A-10C show flat or planar joining elements (e.g., including chamfered joining elements). It should be understood that the joining elements may include curved surfaces (e.g., a concave dome shape, a semi-ellipsoidal shape, a groove shape, a conical shape, etc.) to facilitate the alignment of a joining element of a tip section of a sonotrode with a corresponding joining element of a base section of a conductive pin. It is understood that certain joining elements described here can be used in conjunction with vibrational energy (e.g., ultrasonic energy) and vacuum, so that misalignment between a joining element (e.g., a tip section of a sonotrode) and a corresponding joining element (e.g., a base section of a conductive pin) can be mitigated and improved before ultrasonic welding of the conductive pin to a workpiece.

[0046] With reference to Fig. Figure 6A shows a sonotrode 616 for ultrasonic welding of a conductive pin 608 to a workpiece. The sonotrode 616 comprises a body section (see, for example, body section 116a in Figure 6A). Fig. 1), which is designed to be coupled to the ultrasonic transducer 112b. The body section of the sonotrode 616 terminates at a tip section 616b. The tip section 616b is designed to receive a conductive pin 608. For example, the tip section 616b defines an opening 616b1 for receiving the conductive pin 608. The tip section 616b defines a working surface 616b2 for interacting with a base section 608a of the conductive pin 608. The tip section 616b defines an joining element 616b5, which is designed to join with a corresponding joining element 608a1 of the base section 608a.

[0047] The conductive pin 608 is arranged within the sonotrode 616 (e.g., using the vacuum of a vacuum source) such that a surface of the base section 608a contacts the working surface 616b2 of the sonotrode 616. The conductive pin 608 comprises a base section 608a connected to an elongated section 608b. The conductive pin 608 includes a top tip 608c that defines a hole 608c1. The conductive pin 608 is aligned in a predetermined configuration by joining the joining element 616b5 of the sonotrode 616 with the corresponding joining element 608a1 of the base section 608a. Although the joining element 616b5 of the sonotrode 616 has a slight gap (e.g.,(not shown flush), this gap serves only for illustration; it is understood that the joining element 616b5 and the joining element 608a1 are sufficiently close to each other along their respective circumferences to ensure proper alignment of the conductive pin 608.

[0048] With reference to Fig. Figure 6B shows a bottom view of sonotrode 616. With reference to Fig. Figure 6C shows a top view of the conductive pin 608. In the illustrated embodiments, the joining element 616b5 and the joining element 608a1 are essentially oval and of similar (albeit different) size.

[0049] In Fig. Figure 7A shows a sonotrode 716 for ultrasonic welding of a conductive pin 708 to a workpiece. The sonotrode 716 comprises a body section (see, for example, body section 116a in Figure 7A). Fig. 1), which is designed to be coupled to the ultrasonic transducer 112b. The body section of the sonotrode 716 terminates at a tip section 716b. The tip section 716b is designed to receive the conductive pin 708. For example, the tip section 716b defines an opening 716b1 for receiving the conductive pin 708. The tip section 716b defines a working surface 716b2 for interacting with a base section 708a of the conductive pin 708. The tip section 716b defines an joining element 716b5, which is designed to be joined with a corresponding joining element 708a1 of the base section 708a of the conductive pin 708.

[0050] The conductive pin 708 is arranged within the sonotrode 716 (e.g., using a vacuum source) such that a surface of the base section 708a contacts the working surface 716b2 of the sonotrode 716. The conductive pin 708 comprises a base section 708a connected to an elongated section 708b. The conductive pin 708 includes a top tip 708c defining a hole 708c1. The conductive pin 708 is aligned in a predetermined configuration by joining the joining element 716b5 of the sonotrode 716 with the corresponding joining element 708a1 of the base section 708a. Although the joining element 716b5 of the sonotrode 716 has a slight gap (e.g.,(not flush) in relation to the joining element 708a1 of the base section 708a, this gap is shown for illustrative purposes only; it is understood that the joining element 716b5 and the joining element 708a1 are sufficiently close to each other along their respective circumferences to ensure proper alignment of the conductive pin 708.

[0051] With reference to Fig. Figure 7B shows a bottom view of sonotrode 716. With reference to Fig. Figure 7C shows a top view of the conductive pin 708. In the illustrated embodiments, the joining element 716b5 and the joining element 708a1 are essentially oval and of similar (albeit different) size. The main difference between the ones shown in the Fig. embodiment shown in 7A-7C and in the Fig. The embodiment shown in 6A-6C consists in the fact that the joining element of the conductive pin is the lowest section of the conductive pin (i.e. Fig. 7A-7C) is, in contrast to a feature that is not the lowest feature (i.e., see fitting section 608a1 on a section of the conductive pin 608, which is not the lowest feature of the Fig. 6A-6C is).

[0052] Although the conductive pin 208, the conductive pin 608, and the conductive pin 708 can be understood as an arrangement of different materials (e.g., a rivet, a conductive sleeve, an elongated pin body, etc.), wherein the respective elongated section is generally cylindrical, the invention is not limited thereto. For example, a conductive pin can be a single piece of material (e.g., a bent piece of conductive material), wherein the cross-section of such a conductive pin can generally be rectangular (see, for example, conductive pin 808, conductive pin 908, conductive pin 1008, etc.).

[0053] With reference to the Fig. Figures 8A-8B show a sonotrode 816 for ultrasonic welding of a conductive pin 808 (e.g., an "L"-shaped conductive pin) to a workpiece. The sonotrode 816 comprises a body section (see, for example, body section 116a in Figure 8A-8B). Fig. 1), which is designed to be coupled to the ultrasonic transducer 112b. The body section of the sonotrode 816 terminates at a tip section 816b. The tip section 816b is designed to receive a conductive pin 808. For example, the tip section 816b defines an opening 816b1 for receiving the conductive pin 808. The tip section 816b defines a working surface 816b2 for interacting with a base section 808a of the conductive pin 808. The tip section 816b defines an joining element 816b5, which is designed to engage with a corresponding joining element 808a1 of the base section 808a of the conductive pin 808.

[0054] The conductive pin 808 is arranged within the sonotrode 816 (e.g., using the vacuum of a vacuum source) such that a surface of the base section 808a contacts the working surface 816b2 of the sonotrode 816. The conductive pin 808 comprises a base section 808a connected to an elongated section 808b. The conductive pin 808 includes a top tip 808c defining a hole 808c1. The conductive pin 808 is aligned in a predetermined configuration by joining the joining element 816b5 of the sonotrode 816 with the corresponding joining element 808a1 of the base section 808a.

[0055] With reference to the Fig. Figures 8C-8D show top views of the conductive pin 808 (the size of which has been arbitrarily enlarged for clarity). With reference to Fig. Figure 8E shows a top view of the sonotrode 816.

[0056] With reference to the Fig. Figures 9A-9B show a sonotrode 916 for ultrasonic welding of a conductive pin 908 (e.g., an "L"-shaped conductive pin) to a workpiece. The sonotrode 916 comprises a body section (see, for example, body section 116a in Figure 9A-9B). Fig. 1), which is designed to be coupled to the ultrasonic transducer 112b. The body section of the sonotrode 916 terminates at a tip section 916b. The tip section 916b is designed to receive the conductive pin 908. For example, the tip section 916b defines an opening 916b1 for receiving the conductive pin 908. The tip section 916b defines a working surface 916b2 for interacting with a base section 908a of the conductive pin 908. The tip section 916b defines an joining element 916b5 (e.g., a chamfered section, a rounded section, a fillet section, etc.) designed to engage with a corresponding joining element 908a1 of the base section 908a of the conductive pin 908. It is understood that the joining element 916b5 is shown with a single chamfer width, but a combination of different chamfer widths can also be used (e.g.(a large or shallow chamfer adjacent to a smaller or steep chamfer to facilitate the alignment of the conductive pin 908 when used under vacuum). The joining element 916b5 (defined by the tip section 916b) comprises a chamfered section designed to guide the conductive pin 908 into an aligned position with respect to the sonotrode 916. For example, when a vacuum is drawn through the opening 916b1, a section of the conductive pin 908 (e.g., a corresponding joining element 908a1 of the base section 908a, an edge of the base section 908a) can be drawn against the chamfered section to align and / or position the conductive pin 908 at a desired location within the opening 916b1.

[0057] The conductive pin 908 is shown positioned within the sonotrode 916 (e.g., using the vacuum of a vacuum source) such that a surface of the base section 908a contacts the working surface 916b2 of the sonotrode 916. The conductive pin 908 comprises a base section 908a connected to an elongated section 908b. The conductive pin 908 includes a top tip 908c. The conductive pin 908 is aligned in a predetermined configuration by joining the joining element 916b5 of the sonotrode 916 with the corresponding joining element 908a1 of the base section 908a.

[0058] With reference to the Fig. Figure 9C-9D shows a top view of the conductive pin 908 (the size has been arbitrarily enlarged for clarity). With reference to Fig. Figure 9E shows a view of sonotrode 916 from below. The figures in the Fig. The embodiment shown in 9A-9E may be particularly suitable for linear ultrasonic welding.

[0059] With reference to Fig. Figure 10A shows a sonotrode 1016 for ultrasonic welding of a conductive pin 1008 to a workpiece. The sonotrode 1016 comprises a body section (see, for example, body section 116a in Figure 10A). Fig. 1), which is designed to be coupled to an ultrasonic transducer 112b. The body section of the sonotrode 1016 terminates at a tip section 1016b. The tip section 1016b is designed to receive the conductive pin 1008. For example, the tip section 1016b defines an opening 1016b1 for receiving the conductive pin 1008. The tip section 1016b defines a working surface 1016b2 for interacting with a base section 1008a of the conductive pin 1008. The tip section 1016b defines an joining element 1016b5, which is designed to be joined with a corresponding joining element 1008a1 of the base section 1008a of the conductive pin 1008.

[0060] The conductive pin 1008 is arranged within the sonotrode 1016 (e.g., using the vacuum of a vacuum source) such that a surface of the base section 1008a contacts the working surface 1016b2 of the sonotrode 1016. The conductive pin 1008 comprises a base section 1008a connected to an elongated section 1008b. The conductive pin 1008 includes a top tip 1008c defining a hole 1008c1. The conductive pin 1008 includes a stress relief section 1008d. The conductive pin 1008 is aligned in a predetermined configuration by joining the joining element 1016b5 of the sonotrode 1016 with the corresponding joining element 1008a1 of the base section 1008a.

[0061] With reference to Fig. Figure 10B shows a bottom view of sonotrode 1016. With reference to Fig. Figure 10C shows a top view of the conductive pin 1008 (where the size has been arbitrarily enlarged for clarity).

[0062] As experts know, the shapes of the respective joining elements of the sonotrode and the base sections are simplified in the drawings herein (e.g., in the Fig. 6A-6C, 7A-7C, 8A-8E, 9A-9E and 10A-10C). It is understood that, in order to fulfill the function of aligning the conductive pin in the desired predetermined configuration, the respective joining elements may have a curvature and other features not shown here.

[0063] The Fig. Figures 11-12 are flowcharts illustrating various unclaimed methods for the functional operation of an ultrasonic welding system. As is known to those skilled in the art, certain steps included in the flowchart can be omitted; certain additional steps can be added; and the sequence of the steps can be changed from the sequence shown – all within the scope of the invention.

[0064] With reference to Fig. Figure 11 describes an unclaimed method for operating an ultrasonic welding system (e.g., ultrasonic welding system 100). In step 1100, a conductive pin (e.g., conductive pin 608, conductive pin 708, conductive pin 808, conductive pin 908, conductive pin 1008) is provided at a sonotrode (e.g., sonotrode 616, sonotrode 716, sonotrode 816, sonotrode 916, sonotrode 1016) of the ultrasonic welding system. The sonotrode comprises a body section (e.g., body section 116a) that terminates at a tip section (e.g., tip section 116b, tip section 616b, tip section 716b, tip section 816b, tip section 916b, tip section 1016b). The tip section defines a connecting element (e.g., connecting element 616b5, connecting element 716b5, connecting element 816b5, connecting element 916b5, connecting element 1016b5) designed to connect to a corresponding connecting element (e.g.,In step 1102, the conductive pin is aligned in a predetermined configuration with respect to the sonotrode by joining the connecting element to the corresponding feature of the base section. In step 1104, the conductive pin is ultrasonically welded to a workpiece after step 1102 (e.g., using a torsional motion, a linear motion, etc.).

[0065] With reference to Fig.Figure 12 describes an unclaimed method for operating an ultrasonic welding system. In step 1200, a conductive pin (e.g., conductive pin 208) of a sonotrode (e.g., sonotrode 116, sonotrode 216, sonotrode 216', sonotrode 516) of the ultrasonic welding system is provided. The sonotrode comprises a body section (e.g., body section 116b) terminating at a tip section (e.g., tip section 216b, tip section 516b). The tip section receives the conductive pin. In step 1202, the conductive pin is aligned within an opening of the sonotrode at the tip section using an alignment mechanism (e.g., alignment mechanism 218, alignment mechanism 218', alignment mechanism 218'', alignment mechanism 518). In step 1204, the conductive pin from step 1202 is welded using ultrasonic welding (e.g. using a torsional movement, a linear movement, etc.).) attached to a workpiece.

[0066] Although the invention is illustrated and described here with reference to certain embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications to the details can be made within the scope and range of the equivalents of the claims without departing from the invention. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 63 / 725.093

[0001] US 10,882,134

[0003] US 11,364,565

[0003] US 11,285,561

[0004] US 11.504.800

[0004] US 11.958.124

[0004] US 11.850.676

[0004] US 12.070.814

[0004] US 12.377.489

[0004] US 12.370.620

[0004] US 2025 / 0332654

[0004] US 2025 / 0187103

[0004] WO 2024 / 220203

[0004] US 2025 / 0289074

[0004]

Claims

[1] A sonotrode for welding a conductive pin to a workpiece using ultrasound, the sonotrode comprising: a hull section designed to be coupled with an ultrasonic transducer, wherein the body section terminates at a tip section, the tip section defining an joining element designed to be joined with a corresponding joining element of a base section of the conductive pin, wherein the conductive pin is aligned in a predetermined configuration by joining the joining element defined by the tip section with the corresponding joining element of the base section. [2] Sonotrode according to claim 1, wherein the joining element defined by the tip section comprises an opening designed to join with a form of the corresponding joining element of the base section. [3] Sonotrode according to claim 1, wherein the conductive pin defines a hole at a point along its length, the predetermined configuration relating to an orientation of the hole. [4] Sonotrode according to claim 1, wherein the conductive pin is an “L”-shaped conductive pin, which refers to an orientation of the “L”-shaped conductive pin. [5] Sonotrode according to claim 1, wherein the conductive pin is a power terminal designed for ultrasonic welding in a power module. [6] Sonotrode according to claim 1, wherein the sonotrode is designed to weld the conductive pin to a workpiece using a torsional movement. [7] Sonotrode according to claim 1, wherein the sonotrode is designed to weld the conductive pin to a workpiece using a linear movement. [8] Sonotrode according to claim 1, wherein the joining element defined by the tip section comprises a chamfered section designed to guide the conductive pin into an aligned position with respect to the sonotrode. [9] Ultrasonic welding system, comprising: a support structure designed to hold a workpiece; a welding head assembly comprising an ultrasonic transducer; and a sonotrode carried by the ultrasonic transducer, wherein the sonotrode comprises a tip section, the tip section defining an joining element designed to join with a corresponding joining element of a base section of the conductive pin, wherein the conductive pin is aligned in a predetermined configuration by joining the joining element with the corresponding element of the base section. [10] A sonotrode for welding a conductive pin to a workpiece using ultrasound, the sonotrode comprising: a body section designed to be coupled with an ultrasonic transducer, wherein the body section terminates at a tip section, the tip section being designed to receive the conductive pin; and an alignment mechanism designed to align the conductive pin within an opening of the sonotrode. [11] Sonotrode according to claim 10, wherein the alignment mechanism comprises a first alignment tool for aligning the conductive pin. [12] Sonotrode according to claim 11, wherein the alignment mechanism comprises a second alignment tool for aligning the conductive pin, wherein the first alignment tool is arranged adjacent to a first lateral opening of the sonotrode, wherein the second alignment tool is arranged adjacent to a second lateral opening of the sonotrode. [13] Sonotrode according to claim 12, wherein the first alignment tool and the second alignment tool are designed to be supplied with ultrasonic energy during a pin alignment process. [14] Sonotrode according to claim 12, wherein the first alignment tool and the second alignment tool are designed to vibrate during a pin alignment process. [15] Sonotrode according to claim 12, wherein the first alignment tool and the second alignment tool are spring-based alignment tools. [16] Sonotrode according to claim 10, wherein the alignment mechanism is an alignment tool arranged within the opening of the sonotrode, the alignment tool defining an alignment opening designed to receive an upper tip of the conductive pin. [17] Sonotrode according to claim 10, wherein the conductive pin defines a hole at a point along its length, wherein the alignment mechanism aligns the conductive pin by engaging with the hole within the opening. [18] An ultrasonic welding system comprising the following: a support structure designed to hold a workpiece; a welding head assembly with an ultrasonic transducer; a sonotrode carried by the ultrasound transducer, wherein the sonotrode has a tip section designed to receive a conductive pin, and wherein the sonotrode has an alignment mechanism designed to align the conductive pin within an opening of the sonotrode.

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