Dear Vaughan, It is a very good brainstorming practice. I appreciate very much. But how to measure the before and after (hi/low) to tell the etch depth. Our CMM can only measure up to 0.00001". But the depth is 0.00001-0.00003. We need to consider the tolerance of the CMM as well which reflect the reading accuracy. _____________________________________________________________ At 06:00 AM 1999/4/22 -0700, Vaughan, Ralph H wrote: >Hi Albert, > >I don't have a complete answer for you but in my normal keep-it-simple >methodology, could you not take your copper surfaced control board, mask >areas or patterns (stripes or checkerboard for example) on the surface, then >etch. When you de-mask, you will have adjacent hi/low surfaces that can >be compared. > >Just a thought. > >Ralph Vaughan >Boeing-Atlanta > >> ---------- >> From: Albert Mok[SMTP:[log in to unmask]] >> Reply To: TechNet E-Mail Forum.;Albert Mok >> Sent: Thursday, April 22, 1999 4:40 AM >> To: [log in to unmask] >> Subject: [TN] Microetch depth measurement >> >> Dear technetters, good morning, >> >> Many board shops required microetch process, which is normal the >> pretreatment/pre-cleaning of copper surface prior to subsequent chemical >> processes. We have to control the etch depth, either from the spray >> system, >> or the batch wise bath from autoplating line. The desired etch depth >> varies from process for process but ranging from 20-50 microinch. >> >> We are using one sq. ft. bare board for the etch testing so that the etch >> depth is calculated when we based on the fact that 1 microinch is 0.02g of >> copper for one side. >> >> We hope to collect ideas or to gain your experience for getting this >> results more wisely. We tried of weighing the board, etch, clean and >> weigh >> it again. We are thinking to make some tools for this test so as to make >> the control more easily. We hope to plate copper at a control thickness of >> 30 microinch and use this as a specimen for the control test or to find a >> way telling the etch depth by co-relation. We cannot consider the etch >> chemicals condition since the batch wise and spray application are two >> extremes. >> >> Please kindly offer your ideas and chat. >> >> ################################################################ >> 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 ################################################################