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