Many things are decided through spirited debate.
Dewey
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Stadem, Richard D.
Sent: Thursday, September 15, 2011 2:14 PM
To: [log in to unmask]
Subject: Re: [TN] ENIG versus LFHASL
Phil, I am all for selecting a final finish after several martinis. I
know many designers who I swear do it that way.
-----Original Message-----
From: Phil Nutting [mailto:[log in to unmask]]
Sent: Thursday, September 15, 2011 3:40 PM
To: TechNet E-Mail Forum; Stadem, Richard D.
Subject: RE: [TN] ENIG versus LFHASL
Ok, so we use SMT and PTH circuit boards, all are low speed (20 kHz to
50 kHz), no BGAs, smallest parts are typically 0603, no Bluetooth, no
RF, typically 0.015 pitch. Environment might be a medical office,
airport, semiconductor fab or research lab.
As for all the geniuses getting together to decide... I'm it. There is
no one else that has in depth knowledge of all the possible factors. I
guess I could go out to lunch and discuss it with myself over a couple
of martinis. Yum!
Phil
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Stadem, Richard D.
Sent: Thursday, September 15, 2011 3:19 PM
To: [log in to unmask]
Subject: Re: [TN] ENIG versus LFHASL
Regarding my previous post, I am not saying anyone should not use ENIG.
You just need to be knowledgeable in ALL surface finishes before you
make a selection.
Surface finish is not something you pull out of your hat based just on
whether the CCA is going to be lead-free, although that is definitely
one of the factors.
For example, you need to consider the type of circuitry. If it is an
analog, high RF, Bluetooth CCA for example, ENIG would be your last
choice (it may be too lossy, and if you do not understand what that
means you should not be determining the surface finish alone).
If it is a double sided SMT CCA with BGAs on both sides, with
through-hole parts that require hand soldering, and must be processed
using lead-free solder, why then, ENIG might just be the best choice. Or
it might not. In that case, OSP is definitely not the best choice.
Selection of finish should be left to a team of engineers who know all
of the advantages/disadvantages of each finish and understands
(intimately) his/her particular circuit design types (RF
receiver/converter, digital processor card, power supply card, D/A card,
thermoswitch device, etc,) and there are many to consider. The designer,
process engineer, and quality engineer should also be familiar with the
fabrication capabilities (or conversely, the weaknesses) of the
different fabricators they have a business relationship with, and have
that in mind when selecting a finish also.
It is definitely NOT something a manufacturing engineer alone should
decide based solely on process type or "personal favorite".
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Stadem, Richard D.
Sent: Thursday, September 15, 2011 1:37 PM
To: [log in to unmask]
Subject: Re: [TN] ENIG versus LFHASL
In fact, Werner wrote entire papers about the possible problems with
using ENIG. Here are some;
http://content.yudu.com/Library/A1qwqg/GlobalSMTampPackagin/resources/61
.htm
http://www.trafalgar2.com/documents/Issue_Archive/global_7.3_us_opt.pdf
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Reuven Rokah
Sent: Thursday, September 15, 2011 1:19 PM
To: [log in to unmask]
Subject: Re: [TN] ENIG versus LFHASL
I am in favor of LFHASL because of its robust in processes and storage
conditions. You just have to choose the right alloy in the HASL process.
You can search in the IPC archive and read Werner recommendations, he
was favor of Immersion Silver and against ENIG because of the Ni3Sn4 IMC
layer, High thermal energy (15 degC) at reflow soldering, lnferior
electrical properties of solder joints and other reasons such solder d
black pads.
Reuven
On Thu, Sep 15, 2011 at 8:00 PM, Phil Nutting
<[log in to unmask]>wrote:
> Hello Technetters,
>
> We are having a discussion about the merits of both ENIG and LFHASL.
> In
> 2006 when we switch to a RoHS compliant process we evaluated many
> board finishes and decided, for our volumes, that although ENIG was
> more expensive it was more robust. LFHASL wasn't ready for prime
> time, Immersion Silver was great but required careful storage and
> handling, OSP was not something that fit our process.
>
> Now that LFHASL appears to be more main stream we are reconsidering
it.
> ENIG is not always done in-house at some of our fab shops, so that
> adds time and money to the delivery. These shops now have LFHASL
> in-house, so there is a potential for some savings here. We have been
> given stories of storage issues with LFHASL and other concerns too.
>
> As I recall, the industry recommended method of storage of bare
> circuit boards is in a sealed bag with desiccant, regardless of board
finish.
> Leaving bare boards unwrapped and in an open bin is just plain bad
> practice especially if near the ocean.
>
> Several of us here think LFHASL is now right for our processes.
>
> Please advise if we are off base.
>
> Phil Nutting
> Design for Manufacturing Engineer
> Kaiser Systems, Inc.
> 126 Sohier Road
> Beverly, MA 01915
> Phone: 978-922-9300 x1310
> Fax: 978-922-8374
> e-mail: [log in to unmask]<mailto:[log in to unmask]>
> www.kaisersystems.com<http://www.kaisersystems.com>
> www.linkedin.com/in/philnutting<http://www.linkedin.com/in/philnutting
> >
>
>
> ________________________________
> Note: All the information contained in this e-mail and its attachments
> is proprietary to Kaiser Systems, Inc. and it may not be reproduced
> without the prior written permission of sender. If you have received
> this email in error, please immediately return it to sender and delete
> the copy you received.
>
>
> ______________________________________________________________________
> This email has been scanned by the MessageLabs Email Security System.
> 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
> -----------------------------------------------------
>
--
Best Regards,
*Reuven Rokah*
Mobile: 972-52-60-120-18
Tele-fax: 97239360688
<http://www.rokah-technologies.com/>[log in to unmask]
[log in to unmask]
www.rokah-technologies.com
**
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 MessageLabs Email Security System.
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
-----------------------------------------------------
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
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
-----------------------------------------------------
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
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
-----------------------------------------------------
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
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
-----------------------------------------------------
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
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
-----------------------------------------------------
|
