Dennis, I agree with Steve's comment on the maximum layer counts for the specified thicknesses. However, it goes several steps further. The key to having more than the noted layer count is the PCB facility you use or plan to use and the H/W they have to facilitate such non-standard recipes. 1. Not all shops can process cores around .004 to .006 mil range. Even if they claim to do so, they will have a high scrap rate processing the thin core material. In-turn, this cost is passed onto the customer. The chemistries are not the limitations, but the mechanics. 2. You may end up using .5oz Cu on all layers, which may not work into your Voltage requirements (2.5, 3.3, 5 VDC).n 3. The capital equipment needed at Lamination may not be available. You need proper temperature, pressure and vacuum controls to ensure minimal mis-registration. If using 1-ply constructions, you may be faced with resin starvation, in turn showing up as delamination in your PCA processes. Again, I'm only touching the surface of what needs to be looked at. There are numerous variables that play into how many layers can be achieved with standard thicknesses. Try to deviate outside the normal .028, .062, .093, .125 mil finished thicknesses. Nothing says you can not use .070, .075, etc. Again, this issue is based on what standards you are designing to, ISA, PCI, VXI, etc. The key is the PCB facilities you end up using. Call me should you have further questions. John Gulley Inet Technologies Inc 972-578-3928 ______________________________ Reply Separator _________________________________ Subject: <no subject> Author: Dennis Ward <[log in to unmask]> at Internet Date: 11/4/98 1:28 PM Good afternoon, Quick question. What is the maximum amount of layers an .062" thick boad can contain? What about .093" thick? Thanks Dennis Ward Net to Net Technologies ################################################################ 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 ################################################################