Hi Paul! I just want to thank you for your input...another Technet "nugget" of gold to be saved... -Steve Gregory- I have to agree with Jeffery and Susan. A degree of roughness is normal and solder leveling smoothes the hole so you would not notice it typically. Any of the electroless processes will tend to make moderate roughness visible. That being said, it is still a matter of degree of roughness that is of concern. Your question was "Does this impact on current carrying capacity?" The answer to that question is that, if the copper plating is within your thickness specification, then the roughness of itself will not impact current carrying capacities. Macroscopically (say 50X) the back lit hole with an electroless finish should look rough but round, maybe nodular or striated, but defiantly not like a "star shaped cookie cutter center" with spikes, posts, or flakes of copper sticking in from the edge of the PTH. Be concerned if the minimum hole size is violated. I believe that microsectioning in this case is prudent. Measure the thickness of the copper in the thinnest part of the hole and expect it to measure greater than .0008". Next, look for gouges in the barrel of the hole caused by drilling or etchback and expect them to be .001" or less. Drill gouges are not usually an issue, even if they are large (.002"), but they usually are not greater than .001" either. If you find very large drill gouging or very thin plating a flag should go up and a MRB review is in order. The picture posted looks normal. Paul Reid PWB Interconnect Solutions -----Original Message----- From: Jeffrey Bush [mailto:[log in to unmask]] Sent: Monday, January 24, 2005 9:21 AM To: [log in to unmask] Subject: Re: [TN] Silver plated barrel? does it reduce current carrying ability? This is actually how a copper plated barrel looks. Some what rough drilling, but not an issue unless there are voids in the plating. Immersion coating like tin and silver are thin and will represent the barrel topography. Solder levels the barrel and masks the topography of the walls. Jeffrey Bush Director, Quality Assurance and Technical Support VERMONT CIRCUITS INCORPORATED 76 Technology Drive - POB 1890 Brattleboro, Vermont 05302 Voice: 802.257.4571.21 Fax: 802.257.0011 http://www.vtcircuits.com -----Original Message----- From: Matthew Lamkin [mailto:[log in to unmask]] Sent: Monday, January 24, 2005 6:44 AM To: [log in to unmask] Subject: [TN] Silver plated barrel? does it reduce current carrying ability? I have just noticed the barrels on some boards that we now get silver plated instead of tin plated so as to be lead free. I can clearly see the laminate strands through this hole and many others on the boards. What difference is this from an ordinary tin plated hole? looking at older boards, I can see nice shiny & flat holes & no ridges. Is there something wrong with the holes that have been silver plated or would they look like this anyway? What impact does this have on the current carrying ability of a plated hole? I have managed to get a picture taken of one hole to indicate what I'm on about. http://www.ukxboxgamers.co.uk/BARRELL.jpg Thankyou, Matthew Lamkin. --------------------------------------------------- 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 -----------------------------------------------------