Motor Vehicle Lighting Circuit Carrier Positioning

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Solution Overview

Problem

Existing methods for positioning semiconductor light sources in motor vehicle lighting devices face challenges in achieving high precision due to interference from the manufacturing and coating processes of the optical system, particularly with reflective surfaces, which affects the accuracy of light-emitting area alignment relative to the optical system.

Innovation Solution

A method involving a circuit carrier with stop elements and stop ribs that allow for precise positioning of semiconductor light sources relative to the optical system, independent of the optical system's manufacturing and coating processes, by using stop elements inserted into bores on the carrier, which are designed to maintain accuracy despite conductor tracks and components, and are shaped to minimize paint accumulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the optical system is coated with paint by dipping or spraying process, then the optical surface obtains reflective properties, but paint accumulates on stop surfaces and stop areas affecting positioning accuracy

Engineering Contradiction:
Improvepositioning accuracy of semiconductor light sourceVSAvoidpaint accumulation on stop surface
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The stop surface and stop areas are extracted from the optical system's coated surface. By creating a separate, uncoated positioning interface on the circuit carrier that contacts uncoated stop areas on the optical system, the harmful paint accumulation is eliminated while the optical surface retains its reflective coating for light guidance.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The circuit carrier is segmented into different functional zones: areas with conductor tracks and components for electrical function, and a separate positioning area with contact areas that are free of solder resist and conductive elements. This positioning area specifically contacts the uncoated stop areas of the optical system, separating the electrical function from the positioning function to avoid paint interference.

Inventive Principle:
Principle #1Segmentation

2Manufacturing precision

If the circuit carrier includes contact areas free of solder resist for positioning, then positioning accuracy is improved, but the circuit carrier design becomes more complex

Engineering Contradiction:
Improvepositioning accuracyVSAvoidcircuit carrier design
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The positioning function is merged into the circuit carrier design by integrating contact areas directly onto the carrier substrate. These contact areas are formed as uncoated zones during the manufacturing process, combining the mechanical support function with the positioning function in a single integrated component rather than requiring separate positioning elements.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The contact areas are prepared in advance during the circuit carrier manufacturing process by defining uncoated zones before the solder resist application. This preliminary preparation ensures that the positioning surfaces are ready for precise alignment with the optical system's stop areas, eliminating the need for subsequent masking or special handling during assembly.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3321570B1Method for arranging a circuit carrier and lighting device for a motor vehicle with a circuit carrier arranged according to this method
Publication Date: 2021.12.22 MARELLI GERMANY GMBH
  • EP3321570B1 patent drawingFigure 1
  • EP3321570B1 patent drawingFigure 2~3
  • EP3321570B1 patent drawingFigure 4~5

AI summary

The invention relates to a method for arranging a circuit carrier (30) comprising at least one semiconductor light source (32) in a specific position relative to an optical system (20) of a lighting device of a motor vehicle. To improve the accuracy of the positioning of the semiconductor light source (32) with respect to the optical system (20), it is proposed that a stop surface (400) with projecting stop ribs (402) be formed on the optical system (20), upon which the circuit carrier (30) rests with defined support areas (404). The stop ribs (402) are specially designed to allow paint applied to the optical system (20) to flow off the ribs (402) as much as possible.