Darrell It seem that there is some confusion between SOLDER coverage and SOLDERMASK coverage. IPC-RB-276, the bare board spec, allows exposed copper (copper that is not covered with solder) along the vertical edges and 1% of the other conductor surface that is not covered with soldermask or meant to be soldered. The same specification, IPC-RB-276 Amend. 1, does not allow voids or pinholes in the SOLDERMASK on the "conductor surfaces" of bare boards in any area where solder mask is required, but does allow touchup; vertical edges ARE NOT excluded from soldermask coverage. IPC-A-600E reflects the requirements of IPC-RB-276. The soldermask coverage requirement on bare boards is to prevent inadvertant solder balls attached to the conductors after soldering and which could cause shorting. After the soldering is done and the "soldermask" has done its job, some defects in the soldermask coverage is allowed per IPC-A-610B Amend.1. Of course. the word "base copper" was omitted becasue many of the metals under the soldermask are not always copper. The wording now states that these are okay after assembly if they do not bridge adjacent conductors, but I think the intent was to line out "base copper" and leave it as "expose conductor surfaces". Perhaps the task group chairman of the A-610 group needs to clarify the wording and its meaning Phil Hinton Hinton "PWB" Engineering [log in to unmask] *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * ***************************************************************************