From 3da78c5da1c306f077198ac06114f0b85abc3bc8 Mon Sep 17 00:00:00 2001 From: dickelbeck Date: Fri, 13 Nov 2009 14:37:37 +0000 Subject: [PATCH] default_smd was too big for low density boards --- pcbnew/specctra_export.cpp | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/pcbnew/specctra_export.cpp b/pcbnew/specctra_export.cpp index 990625a56b..fafe3032f3 100644 --- a/pcbnew/specctra_export.cpp +++ b/pcbnew/specctra_export.cpp @@ -993,14 +993,20 @@ void SPECCTRA_DB::FromBOARD( BOARD* aBoard ) throw( IOError ) sprintf( rule, "(clearance %.6g)", clearance+safetyMargin ); rules.push_back( rule ); - // On a high density board, a typical solder mask clearance will be 2-3 mils. + // On a high density board (a board with 4 mil tracks, 4 mil spacing) + // a typical solder mask clearance will be 2-3 mils. // This exposes 2 to 3 mils of bare board around each pad, and would // leave only 1 to 2 mils of solder mask between the solder mask's boundary // to the edge of any trace within "clearance" of the pad. So we need at least // 2 mils *extra* clearance for traces which would come near a pad on // a different net. So if the baseline trace to trace clearance was say 4 mils, then - // the SMD to trace clearance should be at least 6 mils. Also add our safetyMargin. - sprintf( rule, "(clearance %.6g (type default_smd))", clearance + 2.0 + safetyMargin ); + // the SMD to trace clearance should be at least 6 mils. + double default_smd = clearance + safetyMargin; + if( default_smd <= 6.0 ) + default_smd = 6.0; + + sprintf( rule, "(clearance %.6g (type default_smd))", default_smd ); + rules.push_back( rule ); /* see: http://www.freerouting.net/usren/viewtopic.php?f=5&t=339#p474