Warren- "Lines between pins" probably refers to the number of circuit traces between PWB vias. For a given via-to-via spacing (the via, or pin "pitch"), 125/125 most likely means 125 micron lines (traces), with 125 micron spaces between evenly spaced traces, which in English units corresponds to 5 mil lines/5 mil spaces (1 mil is approx. equal to 25 microns). For DIP style IC pins (into plated thru hole "vias"), pins 100 mils (0.100 inches) apart, with a 45 mil dia pad at each pin, can have 5 traces running between the pads, where all traces and clearances are 5 mils nominal. -Michael Alderete, Aerojet You wrote... ------------------------------ Date: Tue, 1 Dec 1998 00:53:59 -0500 From: "Dr. Warren Smith" <[log in to unmask]> Subject: Lines Between Pins In a journal article I am translating (from Japanese into English) regarding PWBs, there are many statements about "lines between pins." Low-end boards have 2 lines between pins. Normal boards have 3 lines between pins. High end boards have 4 lines between pins (at 125/125 lines and spaces). The highest density production boards, apparently, have 5 lines between pins. What is all of this talking about? Lines of *what*? Is this referring to a ratio of pin-to-pin spacing vs. line spacing on the board? Any help you can give me would be appreciated. Thanks in advance. Warren Smith, Friendly Neighborhood Japanese Technical Translator ------------------------------ ################################################################ TechNet E-Mail Forum 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################