Hi Teuven,
I actually have info about this:
· Table 3-2 on IPC-6012 "Qualification and Performance Specification for Rigid Printed Boards" has information regarding thickness for each finish.
· On IPC-4554 "Specification for Immersion Tin Plating for Printed Circuit Boards" there is a formula that describes the "Intermetallic Growth of Tin/Copper (Sn/Cu) with Immersion Tin". For this you can calculate how fast the IMC (the cause of the oxidation) will reach the surface.
Overall, by reading IPC-6012 and the IPC-455X Series you can get a good idea on the effect of baking on oxidation of the different finishes.
Rigo
Sr. Quality Assurance Engineer
Workmanship Standards, Code 300
NASA, Goddard Space Flight Center
Greenbelt, MD 20771
Phone. (301) 286-6129
Fax. (301) 286-6576
From: Reuven Rokah [mailto:[log in to unmask]]
Sent: Thursday, November 17, 2011 1:31 PM
To: TechNet E-Mail Forum; Garcia, Rigo (GSFC-300.0)[MANTECH SRS TECHNOLOGIES]
Subject: Re: [TN] Recommended Bakeout Temperature for Boards and Assemblies
Beside the internal forces caused by the heated moisture there is the oxidation rating, much faster with higher temp.
Do anyone have a graph of this rating (temp. per time per oxidation thickness)? on PCB finish (Imm. Ag, Imm Sn, ENIG, OSP)?
Reuven
On Thu, Nov 17, 2011 at 6:28 PM, Garcia, Rigo (GSFC-300.0)[MANTECH SRS TECHNOLOGIES] <[log in to unmask]<mailto:[log in to unmask]>> wrote:
Good day TechNetters!
I have been reading all sorts of materials regarding bakeout of boards and the consequences. Among some of the documents I've read is IPC-1601 - "Printed Board Handling and Storage Guidelines".
One of the main questions I still have is, if moisture contributes to delamination by the internal forces generated internally on the PCB when heating up the board at high temperatures due to the evaporation of the water, why would anybody recommend temperatures above 100 °C which is the boiling temp for water? For instance, baking at 125 °C would create the same effects we are trying to avoid, wouldn't it?
Does anybody know any good reading material to learn about this?
Thanks for the help!
Rigo Garcia
Sr. Quality Assurance Engineer
Workmanship Standards, Code 300
NASA, Goddard Space Flight Center
Greenbelt, MD 20771
Phone. (301) 286-6129<tel:%28301%29%20286-6129>
Fax. (301) 286-6576<tel:%28301%29%20286-6576>
______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask]<mailto:[log in to unmask]>
______________________________________________________________________
---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 16.0
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
For additional information, or contact Keach Sasamori at [log in to unmask]<mailto:[log in to unmask]> or 847-615-7100 ext.2815<tel:847-615-7100%20ext.2815>
-----------------------------------------------------
--
Best Regards,
Reuven Rokah
Mobile: 972-52-60-120-18
Tele-fax: 97239360688
<http://www.rokah-technologies.com/>[log in to unmask]
<mailto:[log in to unmask]>[log in to unmask]<mailto:[log in to unmask]>
www.rokah-technologies.com<http://www.rokah-technologies.com/>
[http://royiro.weebly.com/uploads/6/3/6/9/6369812/4511319.jpg?303]
This e-mail message is intended for the recipient only and contains information which is CONFIDENTIAL and which may be proprietary of Rokah Technologies. If you have received this transmission in error, please inform me by e-mail, phone or fax, and then please delete all of the original files and all other copies exist.
______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask]
______________________________________________________________________
---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 16.0
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
For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
-----------------------------------------------------
|
