DC25_PAPER_TRACK13_DifferentialSkewMitigationTechResults_Kinney.pdf

1、 Information Classification:General Differential Skew Mitigation Technique Results Chris Kinney,Google Vijay Kunda Yi Amy H Luoh Xiaoning Ye,Intel X Information Classification:General Abstract Each differential pair skew mitigation technique has unique performance and cost tradeoffs.For example,imag

2、e rotation results in significant cost adder due to lower panel utilization,while angled routing often results in unnecessary meandering in routing and sometimes not implementable due to limited routing channel.In this paper,a skew mitigation technique that aligns the trace pitch to the underlying g

3、lass fabric fiber-weave pitch is studied.This leads to a differential pitch that is often larger than the typical differential trace pitch found in current platforms.The wider trace pitch also enables wider trace width and thus lower loss.Given high-frequency low-loss printed circuit board transmiss

4、ion lines have limited material property improvement,wider trace width is often a preferred lower-loss option.Delta-L coupons were tested from two PCB fabrication houses with four state-of-art PCB materials.This paper reports on the skew and insertion loss measurement results using standard IPC weav

5、es matched and unmatched on high performance glass.Absolute skew results are less than 2 picoseconds on 5-inch and 10-inch Delta-L coupons,which is about the measurement accuracy of the test equipment.Evidence also indicates that the lines routed in the weft direction are less impacted compared to t

6、he warp direction.Author(s)Biography Chris Kinney is a signal integrity engineer starting 18 years at Google,Intel,Micron and Kioxia.He is currently working on signal integrity challenges with Google Cloud hardware.He has patents and papers on high-density interconnect technology and power delivery.