Frequency Inverter Plastic Molding for Safe PCB Integration

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Frequency converters pose a risk of accidental contact with hazardous voltages during assembly and disassembly, and existing solutions do not adequately address the need for easy and safe handling of sensitive components.

Innovation Solution

A frequency converter design featuring a three-dimensionally shaped plastic molding with holding means that securely fixes the printed circuit board, preventing accidental contact and reducing assembly complexity, combined with a housing that allows for secure mechanical fixing without additional screws and includes features for safe cable routing and thermal management of power semiconductor components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the printed circuit board is mechanically fixed to the housing using additional screw connections, then the mechanical stability and protection against contact is improved, but the assembly complexity and assembly effort increases

Engineering Contradiction:
Improveprotection against contactVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the protective cover and the mechanical fixing function into a single integrated component. The cover is designed with integrated holding means (lugs, clips, or snap-fit features) that directly secure the printed circuit board to the housing, eliminating the need for separate screw connections. This merging of functions reduces assembly complexity while maintaining reliable mechanical fixation and contact protection.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cover serves multiple functions simultaneously: it provides protection against contact with hazardous voltages, mechanically fixes the printed circuit board in place, and structures the housing assembly. By making the cover multi-functional, the patent reduces the total number of components and assembly steps without compromising reliability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Stability of the object's composition

If the printed circuit board is mechanically fixed to the housing using additional screw connections, then the mechanical stability is improved, but the assembly time increases

Engineering Contradiction:
Improvemechanical stabilityVSAvoidassembly time
Core Design Contradiction:
Stability of the object's compositionVSLoss of time

Solution Approach 1:

The holding means are pre-integrated into the cover structure during manufacturing, so that during assembly the printed circuit board can be directly attached to the housing without requiring separate fixing operations. The cover is designed beforehand with built-in lugs, clips, or snap-fit features that provide immediate mechanical stability upon installation, reducing assembly time while maintaining stability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces the traditional screw-based mechanical fixing system with an integrated snap-fit or clip-based system built into the cover. This substitution eliminates the need for tools and multiple fastening operations, significantly reducing assembly time while maintaining adequate mechanical stability for the application.

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

3Reliability

If the plastic molding is designed to cover the printed circuit board areas, then the protection against hazardous voltage contact is improved, but the accessibility of terminal connectors may be reduced

Engineering Contradiction:
Improveprotection against contactVSAvoidaccessibility of connectors
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The cover is designed with differentiated local qualities: solid covering areas over the printed circuit board for protection, and localized openings or recesses at specific positions to provide access to terminal connectors. This allows the cover to simultaneously provide comprehensive protection where needed while maintaining operational accessibility where required, resolving the contradiction between safety and ease of operation.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2830402B1Frequency inverter
Publication Date: 2020.07.29 LENZE DRIVES
  • EP2830402B1 patent drawingFigure 1
  • EP2830402B1 patent drawingFigure 2
  • EP2830402B1 patent drawingFigure 3

AI summary

A frequency converter (100) comprises: a printed circuit board (1) with areas to be protected against contact, a plastic molded body (2) with retaining means (3) designed to detachably mechanically fix the printed circuit board (1) in the plastic molded body (2), wherein the areas of the printed circuit board (1) to be protected against contact are covered by the plastic molded body (2) in such a way as to prevent contact when the printed circuit board (1) is fixed in the plastic molded body (2), and a housing (4a, 4b) into which the plastic molded body (2) and the printed circuit board (1) fixed in the plastic molded body are inserted.