In a message dated 3/23/99 10:40:29 PM Pacific Standard Time, tamir_ben-
[log in to unmask] writes:

> Hello,
>  The application is a 'SHELLCASE' package which made of a kind of glass with
>  CTE of a bout 4ppm.
>  I would like to know some popular materials used in the PCB's industry
which
>  compatible regarding the CTE and conventional assembly process.
>
>  Tanks In Advance.

Hi Tamir,

    While confessing up front about being a "newbie" as far as having any real
experience concerning the fine details of PCB fab materials, I will say that
my desire to learn more about this stuff was stimulated after attending this
years IPC Printed Circuit Expo. What's the saying?; "The more you learn the
less you know..." certainly applies here.

    Anyways, what I do sometimes when I see something come up on the TechNet
that interests me that I know nothing about, I'll use the internet to search
and learn. So this is what I found:

Go to:  http://www.arlonmed.com

It's a company called:

Arlon Electronic Substrates
9433 Hyssop Drive
Rancho Cucamonga, California 91730
Phone: (909) 987-9533

There's a material they make that uses Kevlar for the fabric and a resin
system they call N5NK which has a CTE of 4-7ppm, it's Tg is 180 C....4ppm is
asking a lot seeing how silicon die itself is 3ppm...

There's also an interesting paper on the site at:

  http://www.arlonmed.com/papers/aramidcte.htm

that gets into a good discussion about low cte substrate materials that you
might find interesting. Anyways, these guys seem like the people you need to
talk to find what you seek...

-Steve Gregory-

################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe:   SUBSCRIBE TechNet <your full name>
To unsubscribe:   SIGNOFF TechNet 
################################################################
Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################