Ultrasonic Welding Power Semiconductor Module Contacts
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power semiconductor modules face limitations in operating temperature, with soldered connections typically restricted to below 125°C, making it challenging to extend this range effectively.
Innovation Solution
The method involves using ultrasonic welding to connect current pickups or current connections in power semiconductor modules, employing a sonotrode to join contact areas with contact elements made of solid copper or copper-containing materials, with specific parameters such as ultrasonic welding power, force, and frequency to form reliable contacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If soldered connections are used to connect contact areas with contact elements, then the manufacturing process is simple and reliable, but the operating temperature range is limited to below 125°C
Solution Approach 1:
The patent changes the joining method from soldering to ultrasonic welding, fundamentally altering the process parameters. Ultrasonic welding uses mechanical vibration and pressure instead of thermal bonding, enabling operation temperatures above 125°C while maintaining manufacturing simplicity through automated contactless energy transfer and precise control of welding parameters (amplitude, pressure, time)
Solution Approach 2:
The patent replaces the thermal-mechanical soldering process with a purely mechanical ultrasonic welding process. The sonotrode transmits ultrasonic vibrations directly to the contact elements, creating metallurgical bonds through mechanical interlocking and diffusion without requiring solder material or high-temperature heating, thus extending the operating temperature range
2Reliability
If ultrasonic welding is used to connect contact areas with contact elements, then the operating temperature range is extended, but the manufacturing process becomes more complex
Solution Approach 1:
The sonotrode is designed to perform multiple functions: it serves as both the ultrasonic vibration source for welding and the mechanical press for applying bonding pressure. This multi-functionality integrates the welding and pressing operations into a single device, reducing overall manufacturing system complexity while ensuring reliable contact connections with extended temperature capability
Solution Approach 2:
The patent merges the ultrasonic welding function and the pressing function into a single integrated process step using the sonotrode. By combining these functions, the manufacturing process achieves high reliability through simultaneous vibration-based bonding and pressure application, without requiring separate welding and pressing equipment
3Strength
If a sonotrode is used to press and weld contact ends to contact areas, then the contact connection is strengthened, but the risk of detachment at edge portions increases
Solution Approach 1:
The patent applies local quality by directing ultrasonic vibration and pressure specifically to the contact end regions that require strengthening, while using a welding direction parallel to edge portions to avoid concentrated stress at vulnerable edge areas. This localized approach strengthens critical connections without compromising edge integrity
4Strength
If ultrasonic welding power and normal force are increased to improve contact connection, then the bonding strength increases, but the risk of damaging contact areas or substrates increases
Solution Approach 1:
The patent employs periodic ultrasonic vibration during the welding process, applying energy in oscillating cycles rather than continuous static pressure. This periodic action allows the material to deform and bond progressively without exceeding damage thresholds, achieving strong contact connections while protecting the contact areas and substrates from ultrasonic welding power and normal force
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for the formation of contacts with extended operating temperature ranges in a simple and reliable manner, enhancing the thermal performance of power semiconductor modules.
Implementation Method 1
at least the first contact end is mechanically and electrically connected to the first contact area to form a first contact and in which a respective contact is formed by means of ultrasonic welding, in that a sonotrode, which is used for the ultrasonic welding process, is also used to join the contact end to the contact areas
Data Source
Figure 1A
Figure 1B
Figure 1C
AI summary
A method for manufacturing a power semiconductor module (1) is proposed in which a contact (40 - 43) between a contact area (20 - 23) and a contact element (30 - 32) is formed as an ultrasonic welding contact by using a sonotrode (50) used for the ultrasonic welding process also to join the contact areas (20 - 22) with the contact ends (33, 34) and thus to join the contacts (40, 42) and the foot areas (F, F1 - F3).