Actually a hole that is "a bit" rough is NOT a bad thing, it provides better adhesion of the copper plating. A wall that is too smooth is usually covered with burned and melted epoxy-fiberglass, leaving a surface that has little affinity for subsequent process. Desmear leaves a smoother surface then etchback and is in most cases prefered here at CAE. Etchback usually increasesd wicking and makes the wall rougher. Sorry, but I don't have another specification to offer. All things in moderation may not be a bad thing if you think about it. Alain Savard, B. Sc. Chemical Process Analyst CAE Electronics Ltd. -----Original Message----- From: Charles E. McMahon [mailto:[log in to unmask]] Sent: August 3, 2000 7:48 AM To: TechNet E-Mail Forum.; Alain Savard Subject: RE: [TN] Hole wall roughness As a follow on to your comment Alain to hole wall roughness. I have seen customers reject boards for hole wall roughness. Using desmear for cleaning after drill leaves a jagged surface of glass fibers when seen in cross-section. Plating to it is fine but it put doubts of hole wall strength in the customers view. As there are no IPC Standards for determining the roughness of a hole wall, can a customer reject a board simply based on a unilateral perception that the hole "looks rough". Is there a specification outside of IPC that is available for this issue. Would appreciate your thoughts. Charles McMahon -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Alain Savard Sent: Thursday, August 03, 2000 7:09 AM To: [log in to unmask] Subject: Re: [TN] Hole wall roughness You could always verify for drilled hole diameter, wicking and nodules with a microsection. Of course this works best after plating and can be inspected as per IPC-6012 and IPC-600. You will also get a general idea of the roughness just by looking at it still on a microsection, this can be checked on the section prior to plating, but there are no IPC standards for it. P.S. Wicking is best seen on a non-metallographic microscope wit a good depth of field. Alain Savard, B.Sc. Chemical Process Analyst CAE Electronics Ltd. e-mail: [log in to unmask] -----Original Message----- From: Shirley Xiao [mailto:[log in to unmask]] Sent: August 3, 2000 5:32 AM To: [log in to unmask] Subject: [TN] Hole wall roughness Is there anyone knows how to measure hole wall roughness after drilling or after plating? (Notes:I've searched TechNet archive but there is nothing about hole wall roughness.) Shirley ############################################################## 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 ##############################################################