Dual-Sided Molded Package Layout for Drop-Test Solder Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As circuit device pads on circuit boards decrease in size, drop tests result in increased failure rates due to increased stress on connections, leading to unreliable solder joints.
Innovation Solution
Implementing a packaged circuit device with varying solder interconnect pad sizes, where larger pads are positioned at critical stress points, such as corners, and corresponding interconnect members are sized to match the uniform size of the circuit board pads, enhancing solder joint reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the size of pads on circuit boards is decreased to reduce electronic device size, then the compactness of the electronic device is improved, but the reliability of solder connections deteriorates due to increased stress during drop tests
Solution Approach 1:
The patent applies local quality by creating non-uniform pad sizes on the circuit board, specifically making corner pads larger than edge and center pads. This localized variation in pad size provides enhanced mechanical support and stress distribution at critical corner locations during drop tests, while maintaining smaller pad sizes at other locations to preserve overall device compactness.
Solution Approach 2:
The patent segments the pad structure into different size categories (corner pads versus edge/center pads) with distinct dimensional characteristics. This segmentation allows each pad type to be optimized for its specific location and stress conditions, with corner pads designed for high-stress support and other pads optimized for signal routing and space efficiency.
2Volume of moving object
If uniform small pad sizes are used on circuit boards, then the overall device size is reduced, but the connection strength at critical stress points (corners) is insufficient
Solution Approach 1:
The patent implements local quality by differentiating pad sizes based on location-specific mechanical requirements. Corner pads are made larger to provide enhanced strength and stress distribution at these critical locations, while edge and center pads maintain smaller dimensions to preserve overall device compactness and meet signal routing requirements.
Solution Approach 2:
The patent introduces asymmetry in the pad layout by making corner pads distinctly larger than edge and center pads. This asymmetric design breaks the uniformity of traditional pad layouts and provides targeted mechanical reinforcement where it is most needed during drop tests, while maintaining space efficiency elsewhere.
Data Source
AI summary
A dual sided molded package has a substrate with pads of varying size configured to receive electrically conductive interconnect members thereon. The pads include first pads that have a larger surface area than a surface area of second pads. In one implementation, one or more first pads are proximate the corners of the substrate. First interconnect members are attached to the first pads and second interconnect members are attached to the second pads. The first interconnect members have an exposed solderable area that is substantially equal to the surface area of the first pads, and the second interconnect members have an exposed solderable area that is substantially equal to the surface area of the second pads. The first exposed solderable area is larger than the second exposed solderable area.