Hey Greg, long time no talk to. The most common oversight in comparing
peroxide and chlorate is understanding consumption and by-products
generated from the reaction. The reaction using peroxide generates 1 mole
of water for 1 mole of cupric chloride regenerated, the reaction using
sodium chlorate generates 1 mole of water for 2 moles of cupric chloride,
half as much water. Also, 1 mole of peroxide consumes 1 mole of copper
whereas 1 mole of sodium chlorate consumes 3 moles of copper. The volume
consumption of 50%by weight Hydrogen Peroxide is 3 times that of CuOx, e.g.
if a process consumes 100 gallons of peroxide per day, when switching to
chlorate they will only use app. 33 gallons of chlorate in the same
conditions. Given the other dilution and stabilization issues with peroxide
it is common for the consumption difference to be closer to 4 times that of
sodium chlorate.

Salt is a by-product generated in the chlorate reaction, which my of us add
over the side to increase etch rate.

Alot of water is generated in the peroxide reaction, which somtimes makes
it difficult to maintain Cu loading. Hope this helps,

---------------------------------------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL
Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
---------------------------------------------------------------------------------