Well, there's 6 minutes of my life I won't get back.  Proving once again 
that some people have entirely WAY to much time on their hands.

Doug Pauls
Rockwell Collins



Steve Gregory <[log in to unmask]> 
Sent by: TechNet <[log in to unmask]>
05/29/2009 09:57 AM
Please respond to
TechNet E-Mail Forum <[log in to unmask]>; Please respond to
Steve Gregory <[log in to unmask]>


To
[log in to unmask]
cc

Subject
Re: [TN] Looking for opinions on separation/delamination between copper 
land and dielectric material.






Okay Inge, here's some light entertainment.

As engineers, I know many of you have struggled with the complex
problems of trying to teach your cats how to yodel.

So, thanks to the wonderful technology of the internet and two engineers
named Paul and TJ, here is a short video called: "An Engineers Guide to
Cat Yodeling" which hopefully solve your dilemma:

http://www.youtube.com/watch?v=aEjKk5Kt3rs&feature=channel

Enjoy B^)

Steve 

---------------------------------
On May 29, 2009 Inge wrote:

Looking forward to the TN Friday light entertainments....have nothing
myself at the moment

Inge






----- Original Message -----
From: "Werner Engelmaier /*" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, May 29, 2009 2:43 PM
Subject: Re: [TN] Looking for opinions on separation/delamination
between copper land and dielectric material.


> Ni hao charming,
> That separation can occur during cooling from solder reflow [if too 
> fast=thermal shock] or in your T-shock test [would have been good to 
> give details.
> Your TSSOP leads are likely Alloy42 [=very stiff] and are very stubby 
> [=very stiff] with SAC-solder  [=very stiff].
> In T-shock it is NOT any CTE-mismatch that causes your problem [even 
> though it does not help, and may cause reliability problems with the 
> product], but the thermal gradients resulting from T-shock and causing

> component/PCB warpage.
>
> How to improve on that? EASY, do not do T-shock in production [slow 
> cooling rate after reflow to 1.5C/sec or less] and in testing go less 
> severe or no T-shock at all.
>
> Werner
>
>
>
>
>
>
>
>
>
> -----Original Message-----
> From: Charming Chan <[log in to unmask]>
> To: [log in to unmask]
> Sent: Fri, 29 May 2009 4:45 am
> Subject: [TN] Looking for opinions on separation/delamination between 
> copper land and dielectric material.
>
>
>
>
>
>
>
>
>
>
> Hello All,
>
> Our guys ran a thermal shock test to verify solder joint reliability 
> of a TSSOP component. The micro-section shows that there is a minor 
> crack at the toe side of the solder joint and a 
> separation(delamination) between the copper land and the dielectric 
> material.
>
> My question is,
>
> Where did the separation/delamination occur? PCB fab house, PCB 
> assembly house, or thermal shock test?
>
> If the separation/delamination occurred at pcb fab house, then, what's

> the possible root cause gonna be?
>
> If the separation/delamination occurred at thermal shock test or pcb 
> assembly house, then, is it caused by CTE mismatch between pcb base 
> material, solder alloy, and gull-wing footprint? How to improve on
that?
>
> Brain storm, and any input is appreciated.
> I will get the micro-section picture posted once I get it. Thank you
all.
>
> Best Regards
> Charming Chan
>
> ---------------------------------------------------
> Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 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 15.0 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 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 15.0 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 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 15.0
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
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 15.0
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
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
-----------------------------------------------------