Here is the abstract you requested from the IMAPS_2009 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|New PCB Materials for Low Skew Close Phase Matching in 10Gbps Differential System Designs|
|Keywords: PCB Material for 10Gbps, Serial transmission skew reduction, Dielectric measurements|
|A new process to weave, flatten and spread the glass reinforcement material has been developed to be used in high performance differentially routed printed circuit boards (PCB’s). This paper describes the features and benefits of this low cost process for modifying conventional PCB glass cloth reinforcement which mitigates the serious effects of intra-pair skew especially for 5, 6.25 and 10 Gigabit per second differential PCB trace designs. Publications recently released by Intel, Teraspeed and others at recent DesignCon meetings and patent submissions point out the need for trace pair parameters which do not vary with respect to the position of the PCB traces above (below) the warp and weft strands of the basket weave of the reinforcing glass cloth. Test cards have been created which compare conventional 106 reinforced FR-4 with a number of modified glass reinforced samples. Measurements have been made utilizing 40 GHz microwave wedge probes in a G-S-G configuration which minimize reflection and maximize transmission. The project has demonstrated that the use of a cost effective process of flattening and spreading of conventional glass reinforcing fiber strands results in the significantly reduced spatial and directional dielectric constant variations in multi-Gigabit differential systems.|
|Dr. Edward P. Sayre, P. E., CTO
North East Systems Associates, Inc.