Dashboard Display Assembly With Removable PCB and Adhesive Carrier

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Solution Overview

Problem

Existing display assemblies for motor vehicle dashboards lack precision and stability, particularly in supporting TFT cells, and do not allow for easy inspection or replacement of printed circuit boards after installation.

Innovation Solution

A display assembly with a pre-assembled module comprising a TFT panel, covering glass, and a carrier with adhesive elements and a centring system, where the carrier is glued to the rear surface of the display and connected to the printed circuit board using pins and screws, allowing for stress absorption and easy removal of the rear covering element for inspection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the rear covering element is fixed to the display with glue or double-sided adhesive tape, then the display assembly achieves structural stability, but the printed circuit board cannot be inspected or removed after installation

Engineering Contradiction:
Improvestructural stabilityVSAvoidinspectability of printed circuit board
Core Design Contradiction:
Stability of the object's compositionVSEase of repair

Solution Approach 1:

The rear covering element is divided into two separate components: a rear cover that is permanently fixed to the display with adhesive, and a separate printed circuit board assembly that can be independently removed. This segmentation allows the rear cover to provide structural stability while the separate PCB assembly maintains accessibility for inspection and repair.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A carrier element is introduced as an intermediary component between the display and the printed circuit board. The carrier serves as a removable interface that allows the PCB to be accessed and removed without damaging the permanently fixed rear cover, thus enabling both structural stability and ease of repair.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If the tolerance chain is small (one tenth of millimetre), then the rear covering element can be directly fixed to the rear structure of the display, but the assembly requires high precision manufacturing

Engineering Contradiction:
Improvetolerance chainVSAvoidassembly complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The carrier element acts as an intermediary that absorbs and compensates for tolerance variations in the assembly process. By introducing this intermediate component with adjustable positioning features, the system can accommodate larger tolerance chains without requiring high-precision manufacturing, thereby simplifying the manufacturing process.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The design allows for adjustment of dimensional parameters of the carrier and PCB assembly to compensate for tolerance variations. By making certain dimensions adjustable rather than fixed, the system can accommodate a wider range of manufacturing tolerances while maintaining proper assembly and function.

Inventive Principle:
Principle #35Parameter changes

3Strength

If the display assembly uses traditional fixing methods with screws and brackets, then the assembly achieves mechanical strength, but the TFT cell is exposed to stresses during assembly and installation

Engineering Contradiction:
Improvemechanical strengthVSAvoidstresses on TFT cell
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

Adhesive elements are applied beforehand to the carrier and display surfaces to create a cushioning layer that distributes and absorbs assembly stresses. This pre-applied adhesive cushioning protects the sensitive TFT cell from the mechanical stresses that would otherwise be transmitted during the screwing and bracket installation processes.

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

Solution Approach 2:

The design replaces direct mechanical fastening methods (screws and brackets attached directly to the display) with an adhesive-based bonding system. The adhesive elements provide the necessary mechanical strength while eliminating the stress concentration and potential damage caused by traditional mechanical fasteners directly contacting the TFT cell structure.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

The solution provides enhanced stability and precision in supporting the TFT cell, absorbs stresses during assembly, and allows for easy inspection and potential replacement of the printed circuit board, while maintaining the structural integrity and safety standards for automotive applications.

Implementation Method 1

the carrier being fixed, by means of adhesive elements, to a rear surface of the display

Methodology Applied
Scientific EffectAdhesive: Adhesive

Data Source

PatentEP4227138B1Display assembly, in particular for a motor vehicle dashboard, and assembling method for assembling such an assembly
Publication Date: 2024.10.16 MARELLI EURO SPA
  • EP4227138B1 patent drawingFigure 1
  • EP4227138B1 patent drawingFigure 2~4
  • EP4227138B1 patent drawingFigure 5~7

AI summary

A display assembly (1), in particular for a motor vehicle dashboard, is provided with a display (3) having a rear surface (8), on which a carrier (12) is arranged; the assembly is further provided with a rear covering element (22) and with a main printed circuit board (11), which is coupled to the carrier (12) by a centring system (13) and is arranged between the carrier (12) and the rear covering element (22); the latter is fixed to the carrier (12) so as to hold the main printed circuit board (11) in position; the carrier (12) is fixed to the rear surface (8) of the display (3) by means of adhesive.