Method for Improved Guidance of Fine Pitch Card Edge Tab Connectors
Publication Date: 2010-Mar-09
The IP.com Prior Art Database
The present invention proposes a connector based on a traditional card edge connector, but allowing a small amount of float of the contacts along the length of the connector.
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Typically, the contacts of the edge card connector ride along the surface of the tab on a printed circuit board (PCB), ideally located in the center of the tab. However, as contact pitch shrinks, the tabs and contacts get closer together, and the risk of shorting (when one contact bridges two pads) and opens (when a contact rides between two pads, failing to make appropriate electrical contact) increases. Card edge interconnect systems are mechanically located with either the rigid edges of the card/connector surfaces, or with a locating key/slot combination. But it has been demonstrated that locating keys wear, allowing for misalignment of the mating interface. With finer pitches emerging in the industry, even slight wear can contribute to significant misalignment. It has also been shown to locate the card with a spring member on the end of the connector. However, neither the locating key solution, nor the spring member, address the issue when the card and/or the connector grow or shrink in the attach process or in the operating environment. Even with slight growth or shrinkage, misalignment and thus shorts/opens can occur. With densities increasing, and pitches decreasing (as is the trend in the industry), the amount of growth/shrinkage tolerance decreases. As card lengths and/or connector lengths increase (as is the trend in the industry), the overall allowable growth/shrinkage as a percentage of total length decreases. This makes it increasingly harder to control.
The present invention proposes a connector based on a traditional card edge connector, but allowing a small amount of float of the...