Rigid-Flexible PCB Layout for Adaptable Power Module Pin Positioning

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing power modules for traction inverters have rigid structures that are inflexible and require expensive modifications to accommodate different applications, limiting their adaptability and increasing production costs.

Innovation Solution

A rigid-flexible PCB power module design that incorporates a rigid portion with conductive paths and a flexible PCB with conductive traces, which can be bent up to 360 degrees without damage, combined with a molding case that allows for flexible positioning of control pins without modifying the leadframe or molding tool.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a rigid structure with rigid leadframe is used for mass production, then manufacturing efficiency and production line stability are improved, but adaptability to different applications deteriorates

Engineering Contradiction:

Improvemass production efficiencyVSAvoidapplication range flexibility

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The PCB is divided into rigid portions and flexible portions. The rigid portions maintain structural stability for mass production, while the flexible portions enable adaptability to different applications through bending and repositioning, resolving the contradiction between production efficiency and application flexibility.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The PCB transitions from a completely rigid structure to a rigid-flexible structure where specific portions can dynamically adjust their position and shape. This allows the same PCB design to accommodate different control pin positions and application requirements without modifying the leadframe or molding tool.

Inventive Principle:

Principle #15Dynamics

2Stability of the object's composition

If control pins are positioned using rigid leadframe, then structural stability is improved, but flexibility in positioning for different applications deteriorates

Engineering Contradiction:

Improveleadframe structural stabilityVSAvoidcontrol pins positioning flexibility

Core Design Contradiction:

Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The PCB is segmented into rigid portions that maintain structural stability and flexible portions that enable control pin repositioning. This segmentation allows the stable leadframe structure to coexist with flexible positioning capabilities for different applications.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The flexible PCB portions act as flexible films that can be bent and repositioned to accommodate different control pin positions, while the rigid portions and leadframe maintain structural stability. This resolves the contradiction between stability and positioning flexibility.

Inventive Principle:

Principle #30Flexible shells and thin films

3Ease of manufacture

If rigid PCB structure is used, then manufacturing simplicity is improved, but application customization capability deteriorates

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidapplication customization range

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The rigid-flexible PCB design allows dynamic adaptation to different applications through the flexible portions, while the manufacturing process remains relatively simple by using standardized rigid portions and leadframes. This enables customization without significantly increasing manufacturing complexity.

Inventive Principle:

Principle #15Dynamics

4Adaptability or versatility

If leadframe modifications are made for different applications, then application-specific optimization is improved, but production line cost deteriorates

Engineering Contradiction:

Improveapplication-specific optimizationVSAvoidproduction line modification cost

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

By segmenting the PCB into rigid and flexible portions, the invention enables application-specific optimization through the flexible portions without requiring modifications to the leadframe or molding tool. This maintains production line simplicity while achieving application customization.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The rigid-flexible PCB design creates a universal platform where the same leadframe and molding tool can serve multiple applications. The flexible PCB portions adapt to different requirements, eliminating the need for expensive production line modifications for each application.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentEP4560694A1Rigid-flexible PCB, power module including the PCB, and manufacturing method of the power module

Publication Date: 2025.05.28 STMICROELECTRONICS INT NV

Figure 1~2
Figure 3~4
Figure 5

AI summary

In a power module, a rigid-flexible PCB (20) exits from a resin molding case, and includes: a first PCB region having a stacked structure of piled up layers; a second PCB region having said stacked structure, further locally delimited at a first side by a top stiffening element (56) and at a second opposite side by a bottom stiffening element (62); and a third PCB region having said stacked structure without the top and bottom stiffening elements. The top and bottom stiffening elements extend at a surface (14c) of the molding case, where the PCB exits from the molding case, and are configured to locally increase the rigidity of the PCB with respect to regions of the PCB 20 where said top and bottom stiffening elements are absent.