From: Paul M Fly Ken, I think IPC-2222 section 9.2.2 will give you what you want. ********************************* Paul Fly Eastman Kodak Company Engineering Technology Center 901 Elmgrove Rd. Rochester, New York 14653-5313 Phone: (716) 726-5670 Fax: (716) 726-0275 E-mail: [log in to unmask] ********************************* Ken Patel <[log in to unmask]> on 16/06/2000 14:01:33 Please respond to "TechNet E-Mail Forum." <[log in to unmask]>; Please respond to Ken Patel <[log in to unmask]> To: [log in to unmask] cc: (bcc: Paul M Fly/243609/EKC) Subject: [TN] component Hole dia v/s lead dia for better solder fillet Guys, It was told to us by our assembly house that PTH/component lead ratio is too tight for good solder fillet and to avoid solder depression (hole is not being completely filled up). I can see there is no de-wetting either on wall or the pin after cross-section. I want to know what that magic number should be. I believe that clearance or the gap between pin and hole - what is the minimum clearance recommenced and what should be maximum clearance for better solder fillet. Is this information available on any IPC document? I have read it but can't remember now. re, ken patel The boards I've seen after cleaning look acceptable. The fact that the holes are not completely filled can also be caused by improper PTH/component lead ratio. I suggest increasing the PTH diameter to alleviate the insufficient fill. ______________________________________________________ Ken Patel Phone: (408) 490-6804 1708 McCarthy Blvd. Fax: (408) 490-6859 Milpitas, CA 95035 ############################################################## 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 ############################################################## ############################################################## 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 ##############################################################