Try 10 mls ammonium hydroxide (ammonia) 10 mls water 10 drops 35% hydrogen peroxide swab on the section 5-8 times with a cotton-tipped swab and rinse immediately with cold water. If you immediately dip the section in an antitarnish, you can keep the copper from staining. If you need better contrast between the copper and the solder (for photographs) you can dip the section in 25% v/v nitric acid prior to the antitarnish - this will turn the solder dark. The etch solution will last for only an hour or two before it no longer is effective. >>> "Eltek Ltd. - Process Engineering" <[log in to unmask]> 03/19/98 07:11am >>> Hi ! What is the composition of solution for microetching of crosssections to show the borders between copper layers ? Edward Szpruch Eltek Ltd - Israel Tel 972 3 9395050 Fax 972 3 9309581 E-mail : [log in to unmask] ################################################################ 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 web site (http://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################ ################################################################ 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 web site (http://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################