" {The reason behind the capability is that the above laminates have a
good balancing of the important qualities, Td, CTE, Z axis stability,
etc. Tg is not that important, previous threads on TN and LF predict
that even 140Tg would do for up to 8 layers, as long as all the other
qualities are properly taken care of.}"
Correct. Even FR-4 laminate will withstand Pb-free temps if the pre-preg
B-stage material is manufactured properly.
Werner Engelmaier suggested a formula that took all of the fab material
properties into consideration and provided a factor to rate its ability
to withstand reflow temperatures. I believe he called it the STII scale.
Werner, do you still have that information?
-----Original Message-----
From: Leadfree [mailto:[log in to unmask]] On Behalf Of Tempea, Ioan
Sent: Tuesday, May 09, 2006 1:47 PM
To: [log in to unmask]
Subject: Re: [LF] Cost pressures starting!
Phil,
I don't think you should be that nervous about Isola 410, it is among
the new laminates, that passed the tests for lead-free capability. At
least this is the info I have got from several PCB fabs. A few months
ago, when we were looking into the PCB issues, there were 3 front
runners, tested for lead-free and UL:
Polyclad PCL-370HR
Nelco 4000-11
Isola IS410
There were also rumors about some Japanese laminates, can't really
remember which.
The reason behind the capability is that the above laminates have a good
balancing of the important qualities, Td, CTE, Z axis stability, etc. Tg
is not that important, previous threads on TN and LF predict that even
140Tg would do for up to 8 layers, as long as all the other qualities
are properly taken care of.
Regards,
Ioan
-----Original Message-----
From: Leadfree [mailto:[log in to unmask]]On Behalf Of Phil Nutting
Sent: Tuesday, May 09, 2006 2:25 PM
To: [log in to unmask]
Subject: Re: [LF] Cost pressures starting!
Ioan,
You are making me nervous. We have switched to specifying Isola 410
with a 170Tg in stiff 0.062" configuration. Are you suggesting it will
delaminate? Yikes! I ran some tests with Isola 402 trying to blister
them, but they took the beating.
Phil
-----Original Message-----
From: Leadfree [mailto:[log in to unmask]] On Behalf Of Tempea, Ioan
Sent: Tuesday, May 09, 2006 12:37 PM
To: [log in to unmask]
Subject: Re: [LF] Cost pressures starting!
Pete,
our first attempt to run lead-free was on a PCB with 170Tg, because we
assumed at that time this would take care of the temperautre raise.
Guess what? We ended up with the most extensive delamination I have ever
seen. And it was a consumer good, 6 layer, lightly populated assembly.
So, if you are lucky and you see delam after the first pass, you will
scrap all the boards in stock, because if it happens it happens on all
the PCBs from that batch. Add the cost of the scrapped material to the
cost of losing the contract because you cannot deliver.
Then, if you are almost lucky, you will see delam after more thermal
excursions. This means that you scrap more material and you cope again
with compromised delivery schedule.
And if you are not lucky, you won't see a thing, you test OK, you ship
and the products die in the field right after that, due to latent damage
to the PCB structure.
Ask your bean counters to make a paradigm shift: they should make sure
that more is charged to the customer. There is no other way.
Regards,
Ioan
-----Original Message-----
From: Leadfree [mailto:[log in to unmask]]On Behalf Of Lee parker
Sent: Tuesday, May 09, 2006 11:02 AM
To: [log in to unmask]
Subject: Re: [LF] Cost pressures starting!
Pete
The variable that the accounts always overlook in cases such as this is
the yield impact. If you continue using 140 Tg materials you will
undoubtedly decrease the yield of your assembly process not to mention
increased customer returns.
You can understand the trade offs by first calculating the cost of a
unit degradation in yield. Then determine how much yield impairment you
can tolerate as a result of continuing to use the present materials in a
more aggressive assembly environment. I imagine any reasonable estimate
in the yield impairment will show an advantage for using the more
expensive high performance materials.
Best regards
Lee
J. Lee Parker, Ph.D.
JLP Consultants LLC
804 779 3389
----- Original Message -----
From: "Pete Houwen" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, May 09, 2006 10:11 AM
Subject: [LF] Cost pressures starting!
> We have successfullly made the transtition, and are beginning to
produce
> complaint products.
>
> And that's starting to drive the bean counters into a frenzy. Our new
PCB
> material spec is calling for 330Td, non-dicy, Z-Axis max, etc... and
guess
> what, - it costs more than the old 140Tg material. Now they want to
go
> back to the old material - throw out a year of research and testing -
> because they ran a few boards using the old material.
>
> The questions are - is anyone running lead free solder processes using
the
> old standard 140Tg, in any kind of volume, with any measurable
quality?
>
> How do you convince them that RoHS just costs more, but it will get
> cheaper eventually?
>
>
------------------------------------------------------------------------
-------Leadfee
> Mail List provided as a service by IPC using LISTSERV 1.8d To
> unsubscribe, send a message to [log in to unmask] with following text
in
> the BODY (NOT the subject field): SIGNOFF Leadfree To temporarily
> stop/(start) delivery of Leadree for vacation breaks
send:
> SET Leadfree NOMAIL/(MAIL)
> Search previous postings 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
>
------------------------------------------------------------------------
-------
>
------------------------------------------------------------------------
-------Leadfee Mail List provided as a service by IPC using LISTSERV
1.8d To unsubscribe, send a message to [log in to unmask] with following
text in the BODY (NOT the subject field): SIGNOFF Leadfree To
temporarily stop/(start) delivery of Leadree for vacation breaks
send: SET Leadfree NOMAIL/(MAIL)
Search previous postings 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
------------------------------------------------------------------------
-------
------------------------------------------------------------------------
-------Leadfee Mail List provided as a service by IPC using LISTSERV
1.8d To unsubscribe, send a message to [log in to unmask] with following
text in the BODY (NOT the subject field): SIGNOFF Leadfree To
temporarily stop/(start) delivery of Leadree for vacation breaks
send: SET Leadfree NOMAIL/(MAIL)
Search previous postings 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
------------------------------------------------------------------------
-------
------------------------------------------------------------------------
-------Leadfee Mail List provided as a service by IPC using LISTSERV
1.8d To unsubscribe, send a message to [log in to unmask] with following
text in the BODY (NOT the subject field): SIGNOFF Leadfree To
temporarily stop/(start) delivery of Leadree for vacation breaks send:
SET Leadfree NOMAIL/(MAIL) Search previous postings 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
------------------------------------------------------------------------
-------
------------------------------------------------------------------------
-------Leadfee Mail List provided as a service by IPC using LISTSERV
1.8d To unsubscribe, send a message to [log in to unmask] with following
text in the BODY (NOT the subject field): SIGNOFF Leadfree To
temporarily stop/(start) delivery of Leadree for vacation breaks send:
SET Leadfree NOMAIL/(MAIL) Search previous postings 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
------------------------------------------------------------------------
-------
-------------------------------------------------------------------------------Leadfee Mail List provided as a service by IPC using LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Leadfree
To temporarily stop/(start) delivery of Leadree for vacation breaks send: SET Leadfree NOMAIL/(MAIL)
Search previous postings 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
-------------------------------------------------------------------------------
|
