The electronics industry, particularly communications, has been moving to higher frequencies and PCB's with denser circuitry. To best of my knowledge, most manufacturers of high frequency circuits clean after soldering to remove flux residues and any possible deleterious effect they may have on high frequency / high speed signals. Recently, my coworkers and I have been asked by customers what effects certain flux residues have on high frequency circuits, and my best answer is they have effects, but we haven't quantified them. I have been asked to measure the high frequency effects of solder paste and flux residues so that Alpha Metals can provide useful physical data on technical bulletins for flux and solder paste products. I've been trying to educate myself by reading elementary textbooks on RF circuits. However, I'm still not sure what kind of physical properties of flux residues assemblers/designers of high speed circuits want to have or how to measure them, including electrical measurement equipment, test coupons and methodology. I really don't want to spend > 40K on a network analyzer or a TDR unless I am sure it will provide useful information for customers. For these reasons, I am submitting the following questionnaire to TechNet Any information you provide will be appreciated. Karen Tellefsen Alpha Metals, Inc Jersey City, NJ 1. Do you assemble RF high frequency / high speed circuit boards? 2. If yes, what generic kind of data concerning solder paste and flux residues would you find helpful in designing or assembling high frequency / high speed circuits? If possible, be specific, e.g. residue dielectric constant, microstrip TDRs with and without residues, etc. 3. Do you measure the effects of solder paste or flux residues on high speed circuits? If yes, how do you measure it, if no, do you have any ideas how to measure it? 4. Do you know of any published work concerning the effect of solder paste and flux residues on high frequency circuits? I am particularly interested in measurement techniques, but data would be useful also. 5. Would you like to collaborate with me on this project? ############################################################## 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. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ##############################################################