Solderless Actuator Connection via Open Metallic Contacts
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Solution Overview
Problem
Conventional soldering methods for electric actuators on printed circuits, especially in automotive dashboard applications, face issues with lead usage, high melting temperatures of lead-free solder pastes, and inadequate mechanical strength, leading to potential damage and increased costs.
Innovation Solution
A solderless connection method using specifically designed metallic contacts with open contact zones, which are stamped or sheared to create a cross-shaped opening, allowing for secure electrical connection without soldering and ensuring mechanical strength through precise self-centering and deformation, enabling efficient and cost-effective assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If lead-free solder paste is used to comply with RoHS directive, then environmental safety is improved, but melting temperature increases from 180°C to 220-230°C which can damage actuators and fragile components
Solution Approach 1:
The invention extracts the connection function from the soldering process by introducing metallic contacts with open contact zones that mechanically receive and hold actuator connection lugs. This eliminates the need for high-temperature soldering of actuators while maintaining electrical connectivity, thereby resolving the contradiction between environmental compliance and temperature damage.
Solution Approach 2:
The metallic contacts serve as an intermediary element between the printed circuit board and the actuator. These contacts are soldered to the PCB but provide a mechanical insertion interface for the actuator, decoupling the thermal process from the mechanical connection and protecting the actuator from high temperatures.
2Object-affected harmful factors
If tulip connectors are used for solderless connection, then actuator trauma is avoided, but mechanical strength is insufficient and additional thermoplastic elements are required
Solution Approach 1:
The open contact zones in the metallic contacts are designed with curved or rounded geometries that allow the connection lugs to be inserted and deformed around them, creating a interference fit. This geometric design provides mechanical retention and strength without requiring additional thermoplastic elements or flanges.
3Ease of manufacture
If press-fit connection is used for solderless connection, then soldering is avoided, but insertion force is high and can damage the printed circuit
Solution Approach 1:
The metallic contacts are pre-soldered to the printed circuit board before actuator installation. This preliminary action creates a robust mechanical and electrical foundation that can withstand the insertion forces of the actuator lugs, preventing damage to the PCB while maintaining the solderless connection benefit for the actuator itself.
4Reliability
If conventional soldering is used for actuator connection, then electrical connection is ensured, but mechanical strength is insufficient under vibration conditions
Solution Approach 1:
The invention merges the electrical connection function and mechanical retention function into a single integrated solution. The metallic contacts provide both electrical connectivity through their conductive material and mechanical strength through their deformed structure that retains the connection lugs, eliminating the need for separate electrical and mechanical connection components.
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 method provides a reliable, cost-effective, and mechanically strong connection for electric actuators on printed circuits, avoiding the trauma of high temperatures and insertion forces, while maintaining electrical integrity and supporting vibrations in automotive applications.
Implementation Method 1
The connection is made by inserting the electrical connection tabs, linked to the actuator, into the metal contacts specially placed on the printed circuit and which have an opening, preferably in the shape of a cross, that the connection tabs of the actuator come through.
Implementation Method 2
The mixture allowing the welding of the contact is deposited beforehand at the location of the contact on the circuit. Once the contacts have been deposited, the circuit is placed in an oven following a defined variable temperature profile.
Data Source
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AI summary
The invention relates to a method of connecting an electric actuator to a printed circuit by means of metal contacts having an open contact zone. The invention is characterised in that the metal contacts are soldered to the printed circuit using an SMD-type automated method which is performed at a high speed and at a high temperature and in that the electrical connection pins of the actuator can be mechanically connected to the metal contacts without soldering by butting the contact zone of the metal contacts against the connection pins of the actuator once said connection pins have been inserted through the contact zone.