Compliant Connector for Stacked PCBs in Harsh Environments
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing connectors for stacked printed circuit boards fail to provide reliable connections in harsh environments due to cracking and breaking of solder joints under extreme temperatures, pressures, and mechanical shock, common in military and space applications.
Innovation Solution
A connector system using flexible polyimide film insulators and copper-covered compliant leads with S, C, or Z shapes, which absorb environmental stress and maintain connections through a press fit or solder joints, ensuring reliability across varying conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional rigid connectors with solder joints are used for stacked circuit boards, then manufacturing and assembly are simple, but the connections become unreliable under extreme temperatures, pressures, and mechanical shock in harsh environments
Solution Approach 1:
The patent employs a flexible circuit board with a thin film structure that can bend and deform to accommodate thermal expansion, mechanical shock, and pressure changes. This flexible construction allows the connector to maintain electrical connections without rigid solder joints that would crack under environmental stress, directly resolving the contradiction between connection reliability and environmental harshness.
Solution Approach 2:
The patent utilizes the elastic properties of the flexible circuit board material, allowing it to dynamically change its physical parameters (bending, expanding, contracting) in response to environmental conditions. This parameter change capability enables the connector to absorb stress without permanent deformation or connection failure, improving reliability under thermal and mechanical stress.
2Reliability
If compliant leads with complex bent shapes are used to absorb stress, then connection reliability improves, but manufacturing complexity increases
Solution Approach 1:
The patent combines the compliant lead structure with the flexible circuit board itself, integrating the stress-absorbing functionality into the base material rather than adding separate complex components. This merging simplifies manufacturing by using a single flexible substrate that inherently provides both structural support and stress compliance, reducing fabrication steps while maintaining solder joint integrity.
Solution Approach 2:
The patent uses composite material construction for the flexible circuit board, combining conductive traces with flexible insulating substrates. This composite structure provides both the electrical connectivity and the mechanical compliance needed to absorb stress, achieving reliable connections without requiring separately manufactured complex bent leads.
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
The solution maintains intact solder joints for over 300 thermal cycles, simulating long-term durability in military and space environments by distributing stress and accommodating minor misalignments, thus providing a reliable connection.
Implementation Method 1
A connector includes a flexible sheet insulator and a plurality of conductive surfaces separated and supported by the flexible insulator. At least one of the conductive surfaces has a hole there through and a bent compliant lead extending there from.
Implementation Method 2
The compliant lead may have a substantially S shape, C shape, or Z shape... maintains connections through a press fit or solder joints, ensuring reliability across varying conditions... maintains intact solder joints for over 300 thermal cycles
Data Source
AI summary
A system for connecting circuit boards is provided. A plurality of overlapping spaced apart circuit boards have a plurality of conductive pins passing through holes in the circuit boards. A connector includes a flexible sheet insulator and a plurality of conductive surfaces separated and supported by the flexible insulator. At least one of the conductive surfaces has a hole there through and a bent compliant lead extending there from. The hole engages one of the pins, and the complaint lead connects to one of the circuit boards.