Motor Vehicle Sensor Marking to Reduce Positioning Tolerances
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Solution Overview
Problem
Existing sensor manufacturing methods for motor vehicles suffer from significant positioning tolerances, leading to reduced precision due to uncontrolled accumulation of multiple manufacturing dimension chain tolerances, particularly in the positioning of integrated circuits and magnets relative to reference systems.
Innovation Solution
A method involving a camera-based positioning system to detect and mark the relative positions of measurement cells and magnetic elements using data matrix codes, reducing the manufacturing dimension chain to two or three tolerances by applying markings that store positional information, enabling precise tracking and correction during production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If multiple manufacturing steps (positioning integrated circuit, overmolding, positioning magnet) are performed using conventional methods, then the sensor can be manufactured, but the positioning tolerances accumulate and reduce sensor precision
Solution Approach 1:
Positioning references are created on the baseplate before the integrated circuit is mounted, and a first marking is applied recording the position of measurement cells relative to these references. This preliminary positioning and marking enables subsequent steps to reference back to these initial positions, preventing tolerance accumulation.
Solution Approach 2:
A camera detects the positioning references and measurement cells to determine their actual positions, and this information is recorded in markings. The detected positions provide feedback that allows correction and precise positioning in subsequent manufacturing steps, ensuring high precision despite multiple operations.
2Ease of operation
If the integrated circuit is positioned relative to reference systems located far away on the baseplate, then the positioning is easier to perform, but the tolerance increases
Solution Approach 1:
Positioning references are created at multiple locations on the baseplate, including positions close to where the integrated circuit will be mounted. This local positioning approach maintains ease of operation while minimizing tolerance by using nearby references rather than distant ones.
3Device complexity
If conventional manufacturing methods are used without positioning markings, then the manufacturing process is simpler, but the reproducibility of sensor manufacturing is reduced
Solution Approach 1:
Positioning references and first markings are created during initial setup steps, establishing a reference framework before subsequent manufacturing operations. This preliminary action enables consistent reproduction of sensor assemblies by providing stable reference points that persist through all manufacturing steps.
Solution Approach 2:
The camera-based detection system records actual positions of components relative to references, and this feedback information is stored in markings. This enables verification and correction of positioning, ensuring high reproducibility across multiple sensors manufactured using the same process.
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
Significantly improves sensor precision by reducing manufacturing tolerances and allowing for precise positioning and correction of elements, ensuring high reproducibility and accuracy in sensor assembly.
Implementation Method 1
placing a camera facing the leadframe so as to generate a sequence of images showing the at least one positioning reference system and the at least one measurement cell or the integrated circuit, detecting the at least one measurement cell or the integrated circuit in the images generated by the camera
Implementation Method 2
the sensor comprises an integrated circuit and a magnet, disposed in line with said integrated circuit, which has measurement cells. Such superposition allows these measurement cells of the integrated circuit to measure the electromagnetic field variations perceived by the magnet
Data Source
AI summary
A method for manufacturing a sensor for motor vehicles, includes placing a camera facing the leadframe to generate a sequence of images showing at least one positioning reference system and at least one measurement cell or an integrated circuit, detecting the at least one measurement cell or integrated circuit in images generated by the camera, determining the position of the at least one measurement cell or integrated circuit relative to the at least one reference system, applying a first marking to the baseplate, the first marking containing information representing the determined position, overmolding the assembly formed by the support zone and integrated circuit, with the at least one reference system still being visible, positioning the magnetic element in the electromagnetic proximity of the at least one measurement cell, detecting the magnetic element in the images generated by the camera, determining the position of the magnetic element relative to the at least one reference system, and applying a second marking to the sensor, the second marking containing information representing said determined position.