Lum Wee Mei said: >I am from Singapore. I am in-charge of a group of layout designer and have >not heard of Hull Cell Scale. >What is this item? Well, I'm from Arkansas, but don't tell anyone, it might hurt my credibility. It was completely in the other corner of the state from Bill, I have relocated long ago to Texas. A Hull cell is a small open tank which is used to test electroplating solutions. A small (about 500 ml) sample of the solution is put in the cell, and prepared anode and polished cathode plate placed in the cell, then current is applied. The cathode is plated, results are used to determine whether the plating solution is performing properly across a range of current densities which vary because of the distance relationship from the anode to the cathode in the Hull cell. The plating will look thin and spotty in the low current density areas, then begin to look OK, and become ugly again when the density is too high resulting in "burned" plating. The "scale" is a small clear ruler which shows the current density (Amps/ft2) at different positions on the test (cathode) plate. This permits small proportional changes in the plating bath chemistry to be made and subsequently test results, predicting the best performance range of the bath. It is of course more easily done in the small test cell than in a large bath with hundreds of gallons of solutions. Generally speaking, it is used to keep the organic addititives at the proper level during production of the plating line, and Hull cell tests are done routinely and periodically to determine the amounts to be added. If the results are really bad, the bath can be carbon filtered or other remedial action taken. If any of this is wrong, remember I'm not under oath, and I may refuse further testimony, change the subject, or start an armed conflict if pursued. regards, Jerry Cupples Interphase Corporation Dallas, TX USA http://www.iphase.com ################################################################ 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 ################################################################