The current high Tg FR4 laminates most widely offered to the North American
market consist of Tg 170 Dicy resin system and Tg170 Phenolic resin system
(huge in Asia but not so widely used or offered in North America). There is
also Nelco -13 which is a modified epoxy resin system that yields a Tg of
210.
Our experience has shown that the standard Dicy Tg 170 resin system is
adequate for most lead free applications. However, it is not "robust".
Sometimes rework or multiple passes in the higher temperature lead free
processes can damage the material.

It is well known that the Phenolic Tg 170 resin system has a higher
Degradation Temperature and therefore can withstand more thermal excursions
but it is not as widely offered in North America.

Nelco has a material which is designed for high speed applications which
boasts a Tg of 210. This material is very robust for lead free applications
but is more expensive than the other resin systems listed above.

As the lead free movement continues to gain momentum the North American
laminate manufacturers will continue to develop more standard FR4 products
designed to meet the higher temperature demands of lead free assembly.

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: "Eddie Rocha" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, August 06, 2004 10:11 AM
Subject: [TN] Laminate for Lead-free assembly


> Can somebody help me with this question? Will PCB fabricators need to use
a
> different type of laminate for the lead free assembly process? I
understand
> the temperatures will be higher for lead-free solders so will the typical
> high temperature FR4's (170-180 Tg) be acceptable?
>
> I ask this because I see a new high temperature FR4 with the same 170-180
Tg
> offered by the laminate suppliers. Is there another requirement for the
> laminate that is needed for lead-free assembly?
>
> thanks,
>
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