We have many customers requesting lead free materials. We use a specific
material with a higher Td which is specifically designed for lead free and
is widely used in Asia where the lead free initiative is much further along.
Our lead free material is actually less expensive than the current "dicey"
cured materials we use for non lead free assemblies.
If you want more information please feel free to contact me off-line.
James Hofer
Director of Operations
Accurate Circuit Engineering
3019 S. Kilson Dr.
Santa Ana Ca. 92707-4202
714-546-2162 work
714-473-6127 cell
[log in to unmask]
----- Original Message -----
From: "Jeffrey Bush" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Wednesday, November 24, 2004 12:34 PM
Subject: Re: [TN] FR4 and Lead free
The issue is not Tg but Td. Some higher Tg materials actually perform
worse than lower Tg materials. It is important develop a test program
to validate your lead free process with specific base materials.
Laminate manufactures offer some variety of thermally stable materials
targeting lead-free, but these are used at a premium. If your lead-free
process can be supported by existing base materials, than that is best
economic solution. The test program will provide the feedback needed.
Please contact me off-line if you need specific information on alternate
base materials and Td for lead-free.
Jeffrey Bush
Director, Quality Assurance and Technical Support
VERMONT CIRCUITS INCORPORATED
76 Technology Drive - POB 1890
Brattleboro, Vermont 05302
Voice: 802.257.4571.21 Fax: 802.257.0011
http://www.vtcircuits.com
-----Original Message-----
From: Black, Paul [mailto:[log in to unmask]]
Sent: Wednesday, November 24, 2004 3:08 PM
To: [log in to unmask]
Subject: [TN] FR4 and Lead free
Hi Tech Gurus,
As people talk more and more about Lead free, I keep hearing that
standard FR boards might not be able to take the extra heat required for
a reliable Lead free solder joint. The problem is that I keep hearing
the word MIGHT. I have not heard that this is definitely true and, if it
is true, I have not heard anyone offer a cost effective solution. So, I
am asking the many experts on this forum, will standard FR4 be able to
handle the higher excursions (particularly, let's say, for a 7" X 9", 8
layer, double-sided SMT, .062" 5/5 board) associated with Lead free
solder paste? If not, what would be the most cost-effective offering
(i.e. high Tg FR4)?
Thank you,
Paul Black
Manufacturing Engineer
Kronos
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