Back-Surface Ground Pattern Notches Prevent Wiring Board Delamination

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Solution Overview

Problem

Existing BLE modules face challenges in maintaining communication quality under harsh conditions, particularly in industrial and in-car applications, due to moisture and heat resistance issues, leading to delamination of wiring layers in the electronic device.

Innovation Solution

The electronic device incorporates a back-surface wide pattern with notches in the back-surface ground pattern to create leak paths for evaporated moisture, preventing internal pressure rise and delamination, while maintaining the reliability and size requirements through a combination of wiring layers and antenna design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a continuous back-surface ground pattern is formed to ensure electrical connectivity and shielding, then electrical performance is improved, but moisture trapped underneath causes internal pressure rise and delamination under heat

Engineering Contradiction:
Improveelectrical connectivityVSAvoidmoisture trapping
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The back-surface ground pattern is divided into multiple separate ground patterns instead of forming a continuous pattern. This segmentation creates gaps that allow moisture to escape from underneath the wiring board, preventing internal pressure buildup and delamination while maintaining adequate electrical connectivity and shielding through the distributed ground patterns.

Inventive Principle:
Principle #1Segmentation

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 configuration enhances the moisture and heat resistance of the BLE module, improving its reliability by preventing delamination and ensuring consistent communication quality in demanding environments.

Implementation Method 1

create leak paths for evaporated moisture

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentUS10396031B2Electronic device with delamination resistant wiring board
Publication Date: 2019.08.27 RENESAS ELECTRONICS CORP
  • US10396031B2 patent drawing
  • US10396031B2 patent drawing
  • US10396031B2 patent drawing

AI summary

This invention provides an electronic device with improved reliability. The electronic device has a wiring board with a back-surface ground pattern formed at the back surface of the board. The back-surface ground pattern is provided with a notch overlapping a region of an upper wiring layer at which a board member is exposed and which is encircled by a wide pattern, the notch permitting the release of water vapor from the region.