Jason:

CEM-1 is a laminate with a random cellulose fiber core, woven glass adjacent to the outside, and a
difunctional epoxy resin.  FR-4 covers a multitude of laminates.  The common factors for the FR-4 family
include woven glass through the laminate and an epoxy resin which may be difunctional or multifunctional.
CEM-1 usually utilizes a low Tg resin while the FR-4 family can cover the Tg range from 110 to over 200 C.

In general, most applications for with plated through holes utilizing CEM-1 have resulted in disappointing
results due to a large Z-axis expansion.  If you require low cost and plated through holes (2 layer
product) you might want to investigate CEM-3 which is a random glass fiber core with woven glass near the
copper and an epoxy resin.

Don Vischulis

Jason Smith wrote:

> Fellow Technetters,  Does anyone have any experience with CEM -1 vs. FR-4?  What
> exactly is CEM1 and it's differences to FR-4?  What reliability issues need to
> be addressed?  A customer is looking for a cost savings on a high volume,
> scarcely populated product.  There is only one IC on it that may need to be glob
> topped or underfilled to handle the CTE of a different type of substrate.
>
> Jason Smith
> Process Materials Engineer
> Lexmark Electronics

################################################################
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
################################################################

################################################################
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
################################################################