Ivan, One method is to use a laser for this Soldermask removal. I have done it several time recently for smaller areas where we used a mask made from thin core copper. Larry ----- Original Message ----- From: Ivan Barrios <[log in to unmask]> To: <[log in to unmask]> Sent: Wednesday, April 26, 2000 12:14 Subject: [TN] Removal of Solder mask > We need to remove a small area (0.120" x 0.100") of soldermask from the top > layer, without removing any of the copper underneath. Is there a chemical > used to "etch" out this soldermask, and not compromise the copper layer > underneath? As always, your responses are most welcome > > Ivan Barrios > > ############################################################## > 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 Keach Sasamori at [log in to unmask] or > 847-509-9700 ext.5315 > ############################################################## > 000000000000000M!5?1kzڿ~ǫ' ȧI4E000000000000000N칻&칻&g,HDUFZ0xmnrN칻&0I@R sD\/~evN˛n Ӆ#sD000000000000000>Wȭȭ/?0+m_ߢfv+bvwf"/y?j"֧r '-rOjƦkjƤ++P?4m000000000000000