Gary, Could not find any requirement on solder mask thickness in the IPC-6012 Rev. B specification. The only paragraph I am aware of dealing with solder mask thickness is the 3.7.3 which states that "solder resist thickness is not measured unless specified in the procurement documents. If a thickness measurement is required, instrumental methods may be used or assessment may be made using a microsection of the parallel conductors on the E coupon." This seems to apply for all IPC classes. Regards, Arnaud Grivon Gary Ferrari a écrit : > The IPC-D-325 has not been revised in several years and it"s > replacement is current in work. To be in accordance with current > specifications, all that is necessary, in addition to the type of mask > you wish to use and the sides to apply it to, is to specify that the > mask meet IPC-SM-840, Type T or H. If you wish a specific mask > thickness, then specify it as well. Only class 3 of IPC-6012 specifies > a minimum soldermask thickness. > > Regards, > > Gary Ferrari > FTG Circuits > Director, Technical Support > 860-350-9300 > > Andrew Clifford wrote: >> I am currently working on the notes section of a new PCB design and >> was pointed towards the examples section in IP-D-325A for some >> suggested notes on the choice of soldermask. The note I have been >> asked to use is: >> >> "Construction to be SMOBD, using liquid photoimageable (LPI) solder >> mask material, type XXXX. Apply to both external layers in accordance >> with IPC, (Type B, Class 2). Use appropriate solder mask artworks for >> each side of board." >> >> I am aware that "Type B, Class 2" has now become Type H (well, Class >> 3, but that is what we are using), but my question is this: >> >> What is the "Type XXXX"? I haven't been able to find much information >> at all in my searches. I found a series of posts on here from 1998, >> in which types B1 and B2 are mentionned, but a source for these was >> never disclosed. >> >> If these are the types in question, I would be very grateful if >> someone could let me know the source of them, as my quality control >> guys will insist on a source if i put it down!!! >> >> Thanks very much for any help you can offer. >> >> Andrew Clifford >> Systems Engineer >> BAE Systems >> Plymouth, UK >> >> --------------------------------------------------- >> Technet Mail List provided as a service by IPC using LISTSERV 1.8e >> To unsubscribe, send a message to [log in to unmask] with following >> text in >> the BODY (NOT the subject field): SIGNOFF Technet >> To temporarily halt or (re-start) delivery of Technet send e-mail to >> [log in to unmask]: SET Technet NOMAIL or (MAIL) >> To receive ONE mailing per day of all the posts: send e-mail to >> [log in to unmask]: SET Technet Digest >> Search the archives of previous posts at: >> http://listserv.ipc.org/archives >> Please visit IPC web site >> http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional >> information, or contact Keach Sasamori at [log in to unmask] or >> 847-615-7100 ext.2815 >> ----------------------------------------------------- >> >> > > --------------------------------------------------- > Technet Mail List provided as a service by IPC using LISTSERV 1.8e > To unsubscribe, send a message to [log in to unmask] with following text in > the BODY (NOT the subject field): SIGNOFF Technet > To temporarily halt or (re-start) delivery of Technet send e-mail to > [log in to unmask]: SET Technet NOMAIL or (MAIL) > To receive ONE mailing per day of all the posts: send e-mail to > [log in to unmask]: SET Technet Digest > Search the archives of previous posts at: > http://listserv.ipc.org/archives > Please visit IPC web site > http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional > information, or contact Keach Sasamori at [log in to unmask] or > 847-615-7100 ext.2815 > ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------