Field Device PCB Spring Grounding for Vibration-Tolerant Assembly

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing field device manufacturing methods require complex screw or clamp connections for grounding electronics, which are costly and prone to friction from vibrations, and necessitate edge metallization on circuit boards.

Innovation Solution

Grounding of field device electronics is achieved through spring contacts, eliminating the need for screw/clamp connections and allowing cost-effective manufacturing without edge metallization, while compensating for tolerances and reducing vibration-induced friction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If screw or clamp connections are used for grounding field device electronics, then reliable electrical connection is achieved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improvegrounding connection reliabilityVSAvoidgrounding structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the grounding function from the complex screw/clamp connection system and implements it through simple spring contacts integrated directly onto the circuit board. This eliminates the need for separate grounding clamps, screws, and associated assembly steps, thereby reducing device complexity while maintaining reliable electrical connection through the elastic contact mechanism.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The spring contacts are self-aligning and self-adjusting through their elastic deformation capability. They automatically compensate for manufacturing tolerances and maintain consistent contact pressure without requiring precise pre-positioning or adjustment during assembly, enabling the grounding system to self-regulate and reduce assembly complexity.

Inventive Principle:
Principle #25Self-service

2Reliability

If screw or clamp connections are used for grounding, then stable electrical connection is achieved, but manufacturing cost increases due to edge metallization requirements

Engineering Contradiction:
Improveelectrical connection stabilityVSAvoidcircuit board manufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent removes the requirement for edge metallization by extracting the grounding function to spring contacts that can be fabricated using standard PCB techniques. This eliminates the need for additional costly metallization processes on circuit board edges, directly reducing manufacturing costs while maintaining stable electrical connection through the spring contact mechanism.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The spring contacts are implemented as inexpensive, simple PCB traces with elastic elements rather than costly metallized edges. This approach uses cheaper manufacturing processes (standard PCB fabrication) to achieve the grounding function, significantly reducing circuit board manufacturing costs while maintaining adequate electrical connection stability.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Reliability

If screw or clamp connections are used for grounding, then firm contact is achieved, but friction increases due to vibration

Engineering Contradiction:
Improvecontact firmnessVSAvoidvibration-induced friction
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent transitions from static screw/clamp connections to dynamic spring contacts that can elastically deform in response to vibration. The spring mechanism absorbs vibrational energy through elastic deformation, preventing the transmission of vibration-induced friction to the contact interface, thereby maintaining firm electrical contact under vibrational conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The spring contacts provide beforehand cushioning by incorporating elastic elements that preemptively absorb mechanical shocks and vibrations. This cushioning effect protects the electrical contact from vibration-induced friction and wear, maintaining contact firmness without requiring over-tightening of screws or clamps.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

4Device complexity

If spring contacts are used for grounding, then manufacturing complexity is reduced, but manufacturing precision requirements increase

Engineering Contradiction:
Improvegrounding structure simplicityVSAvoidspring contact positioning tolerance
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent changes the critical parameter from fixed positional tolerance (required for screw/clamp connections) to elastic deformation characteristics of the spring contacts. By designing the spring geometry and material properties to provide adequate contact pressure over a range of positions, the system tolerates manufacturing variations while maintaining reliable electrical connection, effectively reducing the impact of positioning tolerance requirements.

Inventive Principle:
Principle #35Parameter changes

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 simplifies the grounding process, reduces manufacturing costs, and minimizes friction and complexity by using spring contacts, providing effective electrical connectivity and vibration compensation.

Implementation Method 1

spring contacts or spring fingers (5c), in particular arranged in the edge region (5b) of the first circuit board (5a), have outwardly bent legs and are elastic

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4000360B1Automation field device
Publication Date: 2025.08.06 ENDRESS & HAUSER GMBH & CO KG
  • EP4000360B1 patent drawingFigure 1a~1b
  • EP4000360B1 patent drawingFigure 2

AI summary

The invention relates to an automation field device (1), having: - a housing (2), which surrounds an interior (3); - a sensor- and/or actuator element (4) disposed on the housing (2); - an electronic circuit (5) disposed in the housing (2) for operating the sensor- and/or actuator element (4), wherein the electronic circuit (5) has at least one printed circuit board (5a) with an outer contour, preferably a round outer contour, and has a plurality of spring contacts (5c) in an edge region (5b), wherein the inner contour of the housing and the edge contour of the first printed circuit board (5a) are matched to one another such that the first printed circuit board (5a), with a main plane (E) in which it is formed, can be inserted into the housing (2) orthogonally to a longitudinal axis (L) that extends through the interior (3) of the housing (2), and the spring contacts (5c) are designed and disposed on the first printed circuit board (5a) so as to hold at least the first printed circuit board (5a) in this position in the interior (3) and furthermore to establish an electrical connection between the first printed circuit board (5a) and the housing (2) in order to conduct interference currents from the first printed circuit board (5a) via the spring contacts (5c) to the housing (2).