Susan: Wouldn't you say that some of the thermal caused delamination is repairable? One repair that comes to mind is drilling holes on both sides of the blister and injecting epoxy, pressing down and bake. In this case the blisters are too big and span under some geometries. There were some serious errors in building these boards such as poor cleaning, skipping steps,... Regards, Ramon -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Susan Mansilla Sent: Thursday, November 30, 2006 10:28 AM To: [log in to unmask] Subject: Re: [TN] More delam 1. Are any of these fixable? No, they are not fixable. The one thing that you could do is determine if the delam after the hand soldering is a function of the lot of boards or the hand soldering process. The ground planes in the board present a problem when pre-baking, but you can pre-bake to remove the moisture between the ground plane layers. 2. Would you try, or would you just let them go, or would you scrap them? The boards have to be scrapped, in my opinion, since you now know the extent of the delamination within the board. 3. Can someone interpret what IPC-A-600 means by: -The blister or delamination does not span more than 25% of the distance between adjacent conductive patterns. (adj patterns on the same layer as the delam, or adj patterns on any layer in the board or ...?) For instance, dctest2.jpg spans the conductive patterns on the top layer, but the delam is on an internal layer (of course). IPC-A-600 addresses a bare board. The requirements in it are for bare boards PRIOR to any thermal stressing for blisters and delamination. Since the condition was propagated by the thermal stressing of the soldering process, that alone makes it non-compliant. Susan Hott Robisan Lab --------------------------------------------------- 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 -----------------------------------------------------