PCB Snap-Fit Coupling for Secure Screwless Mounting

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Solution Overview

Problem

The use of screws for mounting printed circuit boards is complex, prone to misalignment, damage, and requires costly cleaning and specialized equipment, and generates debris.

Innovation Solution

A snap-fit fastener system with snap-fit and engagement formations that secure a circuit board to a mount without screws, using polymer materials and resilient clamping to prevent rotation and loosening.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If screws are used to fix the circuit board to the mount, then the circuit board can be securely mounted, but the operation becomes complex and time-consuming due to alignment requirements and potential mis-threading

Engineering Contradiction:

Improvesecure mountingVSAvoidalignment complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The fastening function is divided into two independent parts: a snap-fit connection formation for securing and an engagement formation for anti-rotation. This segmentation allows each feature to perform its specific function without interfering with the other, simplifying the overall assembly process while maintaining secure mounting and preventing rotation.

Inventive Principle:

Principle #1Segmentation

2Reliability

If screws are used to mount the circuit board, then secure fixation is achieved, but material is removed in the form of chips and particulates requiring cleaning

Engineering Contradiction:

Improvesecure fixationVSAvoiddebris generation

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

Instead of removing material through thread-cutting, the invention uses elastic deformation of polymer materials to create the fastening connection. The snap-fit mechanism relies on the elastic recovery of the mount material, converting what would be a harmful material removal process into a beneficial non-destructive joining method that generates no debris.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The traditional mechanical screw-thread system is replaced with a snap-fit elastic deformation system. This substitution eliminates the need for thread-cutting operations that generate chips and particulates, while still achieving secure fixation through the elastic recovery of the polymer mount material.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If screws are used for circuit board mounting, then fixation is achieved, but specialized equipment and cleaning processes are required, increasing cost and production time

Engineering Contradiction:

ImprovefixationVSAvoidproduction cycle time

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The snap-fit fastener is designed to be self-aligning and self-securing. The elastic deformation of the mount material automatically guides the fastener into place and secures it without requiring specialized alignment equipment. The engagement formation with the aperture provides automatic anti-rotation functionality, eliminating the need for additional tools or processes.

Inventive Principle:

Principle #25Self-service

4Reliability

If screws are used to secure the circuit board, then mounting is achieved, but misalignment can lead to poor fixation or damage to the assembly

Engineering Contradiction:

Improvemounting securityVSAvoiddamage risk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The polymer mount material provides inherent cushioning and compliance during the assembly process. The elastic nature of the material absorbs misalignment errors and prevents the hard contact that would occur with rigid screw holes, thereby protecting both the circuit board and mount from damage while still achieving secure fixation.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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

Provides a secure, cost-effective, and efficient mounting solution that reduces production time and risk of damage, while eliminating the need for specialized tools and debris generation.

Implementation Method 1

a first snap-fit connection formation for establishing a snap-fit connection with a second snap-fit connection formation provided on the mount for securing the circuit board thereto

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

the first engagement formation is configured to key through an aperture provided in the circuit board for preventing rotation of the circuit board relative to the fastener

Methodology Applied

Scientific EffectGeometric constraint: Geometry

Data Source

PatentEP3922866B1A fastener and coupling for connecting a circuit board to a mount

Publication Date: 2025.11.05 APTIV TECHNOLOGIES AG

Figure 1
Figure 2~3
Figure 4~5

AI summary

A coupling (1) for connecting a circuit board (14) to a mount (3) with a fastener (2). The mount (3) may be connected to a component. The fastener (2) includes a first snap-fit connection formation (7,8) for establishing a snap-fit connection with a second snap-fit connection formation (9,10,11) provided on the mount. When connected, the fastener (2) clamps the circuit board (14) against the mount (3). The fastener (2) further includes a first engagement formation (5) configured to engage with a second engagement formation (12) on the mount for bracing the snap-fit connection.