Out of curosity, why is HAL not recommended for controlled Zo? Thanks. Brian Ellis wrote: > Hi! > > I do not recommend HAL for UHF boards: the flux residues are damn hard > to remove and the hygroscopicity of them may be limitative, especially > if you do decide on an FR-4. You may also care to consider 35 µm copper > (1 oz) on the inner layers for a better connection to through > holes/vias. Does the fact that 2 x 1080 is specified suggest controlled > impedance? If so, be prepared to find the high resin:glass ratio will > give a slightly higher dielectric constant than a more usual build. Also > HAL is definitely NOT recommended for controlled Zo. > > Brian > > Ko Adeline-FSGA2298 wrote: > > > > > Hi there, > > > > > > My engineer is asking me to design a 900Mhz 4-layer brd using the > > > following information. > > > As this is my first time doing such a high freq brd. > > > I wish to know, is this PCB material perform excellent in high freq. > > > > > > PCB Info > > > Top layer --> 1/2 oz copper > > > Prepreg --> 2 X 1080 > > > Layer 2 --> 1/2 oz copper > > > Prepreg --> 2 X 7118 > > > Layer 3 --> 1/2 oz copper > > > Prepreg --> 2 X 1080 > > > Bottom --> 1/2 oz copper > > > > > > Brd finishing thickness : 0.031" +/- 0.005" > > > Material : FR4. > > > Plating : Tin / Lead 63/37 HAL > > > > > > Thanks & Best Rdgs > > > Adeline Ko > > > > ############################################################## > > TechNet Mail List 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 web site (http://www.ipc.org/html/forum.htm) for additional > > information. > > If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or > > 847-509-9700 ext.5365 > > ############################################################## > > ############################################################## > TechNet Mail List 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 web site (http://www.ipc.org/html/forum.htm) for additional > information. > If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or > 847-509-9700 ext.5365 > ############################################################## ############################################################## TechNet Mail List 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 web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################