CEM 1 has a cellulose pape core with woven glass on the outside, all
impregnated with an epoy resin.

CEM 3 has a non woven glass core with woven glass on the outside, all
impregnated with an epoxy resin

FR4 is all woven glass fabric impregnated with epoxy resin.

All are available with UL 94-V0 flammability rating.

CEM 1 tends to be used for single sided. CEM 3 and FR4 for pth

CEM 1, CEM 3 and FR4 are all NEMA classifications, maybe, just maybe.
there's more info on the NEMA web site at www.nema.org

> ----------
> From:         Tom Burek[SMTP:[log in to unmask]]
> Reply To:     TechNet E-Mail Forum.;[log in to unmask]
> Sent:         25 May 1999 23:25
> To:   [log in to unmask]
> Subject:      [TN] Compare CEM-1, CEM-3 and FR4
>
> Can anyone tell me what CEM-3 is?  How does this differ from CEM-1 and
> FR4?  Is there a WEB site that list this information in one site?
> Thank You,
>
> Tom Burek
> [log in to unmask]
>
> ################################################################
> 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
################################################################

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