Card Edge Connector Solder Pad Staggering for Crosstalk Reduction
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Solution Overview
Problem
Existing electrical connectors with densely arranged solder balls on contact tails experience significant crosstalk, which impairs high-frequency communication.
Innovation Solution
The electrical connector features an insulative housing with two rows of contacts, where solder pads are alternately arranged in opposite directions and offset from each other to maintain a constant distance, preventing crosstalk, and include a retaining section, a deflectable contacting section, and a tail section with a connecting section and solder pad, allowing for optimal spacing and reduced interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If solder pads are arranged closely to increase density, then the connector can accommodate finer pitch contacts, but crosstalk between adjacent solder pads increases significantly
Solution Approach 1:
The solder pads are arranged asymmetrically in a staggered pattern where pads in adjacent rows are offset from each other in the longitudinal direction. This asymmetric arrangement increases the effective distance between pads in neighboring rows, reducing capacitive coupling and crosstalk while maintaining high density. The offset distance is designed to be at least 0.05 inches to ensure adequate isolation.
Solution Approach 2:
The invention transitions from a simple grid arrangement to a three-dimensional staggered configuration by introducing offset in the longitudinal dimension. This dimensional change allows pads to be densely packed in the transverse direction while maintaining separation in the longitudinal direction, effectively reducing crosstalk without sacrificing density.
2Object-affected harmful factors
If solder pads are spaced far apart to reduce crosstalk, then signal integrity improves, but the connector density decreases
Solution Approach 1:
By utilizing the longitudinal offset dimension, the design achieves effective pad separation without increasing the transverse pitch. The staggered arrangement allows maximum utilization of available space in three dimensions, maintaining high density while providing adequate isolation distance for signal integrity.
Solution Approach 2:
The contacting section is designed to be deflectable, allowing the contact to flex during insertion and mating operations. This dynamic characteristic enables the contact to accommodate variations in board position and solder pad location while maintaining reliable electrical connection, facilitating the use of offset staggered arrangements.
Data Source
AI summary
A card edge connector includes an insulative elongated housing, two rows of contacts disposed in the housing. The housing includes a pair of side walls extending along the longitudinal direction with a receiving slot therebetween in a transverse direction perpendicular to the longitudinal direction. The receiving slot is configured to receive a card type memory module. Each contact is equipped with the solder ball for surface mounting upon the printed circuit board. The contact includes a retaining section secured to the housing, a deflectable contacting section extending upwardly from the retaining section, and a tail section extending downwardly from the retaining section and including a connecting section and a solder pad. The solder pads of the contacts in a same row along the longitudinal direction are alternately arranged in opposite directions in the transverse direction perpendicular to the longitudinal direction.