Dear All, We are currently attempting to verify our work on PCB substrate utilisation. We believe that it is possible to extract technology related constants from PCB layouts and use these to estimate the size (and hence cost) of new layouts from the same design stable. As a spin out from this work we have noted that many layouts utilise the substrate area poorly and hence are larger or use more layers than necessary. We have used some locally collected data to verify that the theory is sound, but we need a larger volume of data in order to broadly characterise the types of electronic systems in current production and to validate the model more generally. We believe that the best hand layouts achieve a trace utilisation of about 64%, while the average utilisation is only 30% with the average FALLING through the past decade. The least efficient designs achieve utilisations of only 10% - 15%. We can hypothesise several be good technical reasons for low utilisations, and we would expect to find evidence for these in a large enough survey. To collect data we have produced an online form that calculates PCB trace utilisation from the data avalable on typical EDA tools. The form has an option to send the data to us, where we will use it as part of our survey. If you are able to help, or would simply like to know more about our work please follow the link below: http://pc-ensmh.lboro.ac.uk/prime1/ ------------------------------------------------ Paul J Palmer Senior Research Fellow, PRIME Faraday Partnership, Dept of Manufacturing Engineering, Loughborough University, Loughborough, LE11 3TU Tel: +44 (0) 1509 222940 Fax: +44 (0) 1509 222912 mobile: 07885 573364 URL: http://www.lboro.ac.uk/faraday/ ______________________________________ ------------------------------------------------ Paul J Palmer Senior Research Fellow, PRIME Faraday Partnership, Dept of Manufacturing Engineering, Loughborough University, Loughborough, LE11 3TU Tel: +44 (0) 1509 222940 Fax: +44 (0) 1509 222912 mobile: 07885 573364 URL: http://www.lboro.ac.uk/faraday/ ______________________________________ ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ##############################################################