Electronic Module Sensor Positioning via PCB Through-Hole

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Solution Overview

Problem

Existing electronic modules in automotive transmissions face challenges in protecting electronic components from aggressive transmission fluids and managing the installation and positioning of sensor elements, which can be prone to mechanical stress and thermal expansion issues.

Innovation Solution

The electronic module design features a circuit board with a potting compound covering electronic components, including a socket for screwable connections that allows for flexible sensor element positioning without mechanical stress, using a thermoset material for the potting compound to ensure stability and protection from transmission fluids, and embedding electrical connections within the compound for added protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a sensor element is installed in a plastic carrier with mechanical preload, then the sensor position is fixed, but the assembly becomes complex and cannot be changed without complex modification

Engineering Contradiction:
Improvesensor position stabilityVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The sensor element is extracted from the plastic carrier and directly mounted on the PCB. The through-hole in the PCB provides direct access to the sensor element, eliminating the need for the plastic carrier and its associated mechanical preload system. This simplifies the assembly while maintaining sensor position stability through the potting compound that secures the sensor in place.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The mounting function previously performed by the plastic carrier is merged into the PCB structure itself. The through-hole in the PCB combined with the potting compound creates an integrated mounting solution that both positions and secures the sensor element, eliminating the need for separate carrier components.

Inventive Principle:
Principle #5Merging (Combining)

2Ease of manufacture

If the circuit board is subjected to mechanical stress from sensor installation, then the sensor can be mounted, but the circuit board may be damaged

Engineering Contradiction:
Improvesensor installation easeVSAvoidcircuit board integrity
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The potting compound is applied beforehand to secure the sensor element in the through-hole, creating a cushioning effect that prevents mechanical stress from being transmitted to the PCB during operation. The compound absorbs hydraulic pressure and prevents force transmission to the circuit board.

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

Solution Approach 2:

The potting compound acts as an intermediary between the sensor element and the PCB. It provides the necessary mechanical support and stress absorption, preventing direct force transmission from the sensor to the circuit board while still allowing secure mounting.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If transmission fluid is exposed to electronic components, then the components are accessible, but the components are damaged by aggressive fluid

Engineering Contradiction:
Improvecomponent accessibilityVSAvoidfluid aggression to electronics
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The electronic components and sensor element are nested within the potting compound, which is itself mounted on the PCB. This nested structure provides multiple layers of protection, with the potting compound serving as a barrier that prevents transmission fluid from reaching and damaging the electronic components while allowing the sensor to remain accessible through the through-hole.

Inventive Principle:
Principle #7Nested doll (Nesting)

4Adaptability or versatility

If different materials are used for carrier and circuit board, then mounting is possible, but thermal expansion differences cause problems

Engineering Contradiction:
Improvematerial selection flexibilityVSAvoidthermal expansion stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The potting compound is selected to have thermal expansion properties that are homogeneous with or compatible to those of the PCB. This eliminates the thermal expansion mismatch problems that would occur between dissimilar materials like plastic carriers and PCBs, ensuring stability across temperature variations.

Inventive Principle:
Principle #33Homogeneity

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 design enables easy adaptation of sensor element positioning, eliminates mechanical stress, and provides effective protection against transmission fluids and thermal expansion, ensuring reliable operation under hydraulic pressure without the need for additional carriers or fasteners.

Implementation Method 1

a potting compound arranged on the first side which covers the electronic components

Methodology Applied
Scientific EffectPhysical containment: Physical Containment

Implementation Method 2

using a thermoset material for the potting compound to ensure stability and protection from transmission fluids

Methodology Applied
Scientific EffectThermal stability:

Implementation Method 3

the medium channel being in fluid communication with the sensor element

Methodology Applied
Scientific EffectHydraulic pressure transmission: Pressure Increase

Data Source

PatentEP3649835B1Electronic module and combination of an electronic module and a hydraulic plate
Publication Date: 2023.12.20 ROBERT BOSCH GMBH
  • EP3649835B1 patent drawingFigure 1
  • EP3649835B1 patent drawingFigure 2~4
  • EP3649835B1 patent drawingFigure 5~6

AI summary

The application relates to an electronic module (1), more particularly a control module or sensor module for a motor vehicle transmission, having a circuit board (2) having a first side (21) and a second side (22) facing away from the first side (21), electronic components (24) arranged on the first side (21) and a casting compound (8) arranged on the first side (21), which casting compound (8) covers the electronic components (24). It is proposed that the circuit board (2) has a through-hole connecting the first side (21) to the second side (22) and that a sensor element (4) covering the through-hole (23) is arranged on the first side (21) of the circuit board (2). The application also relates to a combination of an electronic control module of this kind and a hydraulic plate, wherein the second side (22) of the circuit board (2) of the electronic control module (1) lies flat on a surface (31) of the hydraulic plate (3) and the hydraulic plate (3) has a medium channel (33) which opens at the surface (31), wherein the medium channel (33) is fluidically connected to the sensor element (4).