Joel I am glad to here that you are successfully using ENIG boards; unfortunately this has not been the case with some other OEMs and CMs. Almost every week in this forum, I see a report of a problem with ENIG. I myself spent this spring moving several clients from ENIG to other solderability coatings. It has been my experience that if the gold thickness is <2 microinches there is a serious risk of poor solderability. If the gold thickness is> 4 microinches black pad may become a problem. The issue can also be elevated or diminished by the particular plating chemistry and the ability of the fabricator to control the process. Consequently, I often work with clients to evaluate and migrate too other hard metal finishes such as immersion silver and flash gold. The attributes of immersion silver have been discussed here at length many times and I am an advocate. I installed the first immersion silver line in North America at the AT&T plant in Richmond. I then worked with most of the AT&T assembly locations to verify the process. Flash gold is more recent and is found mostly in Chinese PCB shops where it has been resurrected and improved upon. In fact, we used a similar process at the AT&T facility in Richmond many years ago for “other” OEM boards. Most Chinese shops have installed the process and have made substantial improvements. The price is competitive. I along with others will be giving a paper on this process at the IPC February meeting. As an aside, this is probably the first novel technology innovation to originate in the Chinese PCB industry and we should all take notice. I believe we are seeing the same ingenuity in the Chinese PCB shops that Marco Polo found on his first visit to China when he returned to Venice with firecrackers and gun power. Best regards Lee J. L. Parker Ph.D. JLP Consultants LLC (804) 779 3389 -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Joel Mearig Sent: Tuesday, October 11, 2005 3:54 PM To: [log in to unmask] Subject: Re: [TN] Hasl Lee, Good input that I agree with. However, I was wondering if you could further discuss the "flash" vs. "ENIG" issue. I have been using ENIG on my Pb-free assemblies for about 7 years with very little problems. If I am missing something further education would be extremely helpful. Thanks Joel Mearig Delta Tau Data Systems, Inc. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Lee parker Sent: Tuesday, October 11, 2005 10:03 AM To: [log in to unmask] Subject: Re: [TN] Hasl Ramon After reflowing a soldered surface, you will form a meniscus which will interfere with SMT component placement. To avoid the problem I suggest a flat metal finish such as immersion silver or flash gold (not ENIG) Best regards Lee J. Lee Parker, Ph.D. JLP Consultants LLC 804 779 3389 ----- Original Message ----- From: Dehoyos, Ramon<mailto:[log in to unmask]> To: [log in to unmask]<mailto:[log in to unmask]> Sent: Tuesday, October 11, 2005 12:52 PM Subject: [TN] Hasl Hi technetters: Is there a fine pitch limit to the use of HASL board plating finish due to its variation in thickness? Does selective solder strip and reflow plating, SSSR, have a significant advantage over HASL? Any comments relating to platting finish would be greatly appreciated. I thank you for your comments. Ramon ME 410.552.2210 --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask]<mailto:[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]<mailto:[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]<mailto:[log in to unmask]>: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives<http://listserv.ipc.org/archives> Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16<http://www.ipc.org/conten tp age.asp?Pageid=4.3.16> for additional information, or contact Keach Sasamori at [log in to unmask]<mailto:[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 ----------------------------------------------------- --------------------------------------------------- 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 -----------------------------------------------------