A pad the same size as the end termination or only slightly larger, say .005" on three sides, is desirable for chip caps and resistors. It provides the optimum amount of solder without additional unecessary solder that can lead to chip cracking issues. And whenever you need to rework these, you should never touch them with a solder iron as that will thermally shock them and also lead to cracking, depending on the type. Use a hand-held hot-air soldering tool. Hakko and Pace are two suggested sources. But there are many others. Once the operator aquires the skill, it is much faster than trying to unsolder or solder a chip cap with a standard solder iron. When soldering, if you solder one end first and then the other, as the solder cools on the second termination it applies a very large stress to the component. This can eventually lead to cracks. Using a hot-air pencil allows you to solder both ends of the termination at once, and this provides the same equilibrium of force as the original reflow solder process. Go to the AVX website for a lot of good information on pad geometry as related to reliability. They also have a lot of good info on rework. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of - Bogert Sent: Tuesday, November 22, 2005 4:27 AM To: [log in to unmask] Subject: [TN] Making existing PWB land areas larger November 22, 2005 Folks we have an OEM who designed a PWB with too small a land area for mounting a surface mount tantalum chip capacitor. This design does not allow for replacing the capacitor via manual soldering with an iron since the part will be damaged if the iron touches the part body. Is there a way to enlarge the existing land size by some type of solder on land piece. I know they make such an item that folks use for replacement of damaged traces. If the lands can be increased in size, --------------------------------------------------- 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 ----------------------------------------------------- how does one do this and will a reliable solder connection result? --------------------------------------------------- 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 -----------------------------------------------------