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Modified VHDM* connectors and modular flexible circuitry allowing for increased design flexibility and manufacturability

IP.com Disclosure Number: IPCOM000029050D
Original Publication Date: 2004-Jun-14
Included in the Prior Art Database: 2004-Jun-14
Document File: 8 page(s) / 161K

Publishing Venue

IBM

Abstract

Today's complex high-speed applications often need to address high density electrical interconnect as well as mechanical flexibility requirements and stringent cost criteria. Utilizing modular connectors and flexible circuitry, designers can address these issues without adversely affecting design flexibility and manufacturability.

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Modified VHDM* connectors and modular flexible circuitry allowing for increased design flexibility and manufacturability

High density connectors such as the 8-row VHDM* solder tail are required to be used in advanced flex applications. In the case of a complex system, the combination of multiple VHDM connectors and signal wiring results in a complex flex circuit with significant manufacturing concerns, increased cost and risk. The circuit has approximately a large number of connector vias and thousands of inches of wiring.

     This invention allows the cable to be split into modular sections, thus reducing complexity and manufacturing risk. For example, a modular 2-drawer cable could be used twice to create a 3-drawer system, three times for a 4-drawer system, four times if a 5-drawer system was added to plan in the future. Due to the "return loop" requirements on a multi-drawer system, a 3, 4 or 5-drawer return loop cable would be needed along with the individual modular drawer-to-drawer cables. Since the return loop runs at 2/3 the speed of the drawer-to-drawer segments and does not have the same flexibility requirements as the drawer-to-drawer sections, the cross section of this cable may be optimized differently. This invention also allows additional design flexibility by allowing multiple circuits, normally too stiff to be bonded together, to be stacked without mechanical flexibility penalties.

     This invention removes the middle ground pin in a high density connector such as the 8-row solder tail VHDM connector application. In the area of the removed pin, the mating flex cable is slit to allow a the cable to be subdivided. This takes advantage of the VHDM connector pinout of the bus with 4 in and 4 out signal pins per row of connector. The remaining six ground pins and continuity of these ground pins in every blade of the connector will limit any significant signal degradation caused by splitting the cable. The advantage of this invention is it allow a complex cable to be broken into pieces, reducing the manufacturing risk (yields and the ability to deliver manufacturing volumes), cable compl...