Help needed in interpretation of IPC-6012.

Appendix A (page 37) calls out Table 3-8 and Paragraph 3.6.2.13 for
External Conductor Minimum Thickness after plating.

Table 3-8 shows that Minimum Surface Thickness after processing is 3.295
mils when the starting foil weight is 2 Oz.

Our company specifies the finished copper weight as 2 Oz on the drawing.
We do not specify the starting foil weight. PCB manufacturer is allowed
to choose a material that he has in stock and plate it up to be 2 Oz.

My question is - What minimum surface conductor thickness after
processing shall be targeted if the starting foil weight is not 2 Oz?
(The PWB house insists on having the conductor thickness 2.8 mils after
processing. However, I cannot find such a number in IPC-6012.)
  
Thank you,   

Veronika Anderson, C.I.D.
Senior Electrical / Mechanical Designer
 
PerkinElmer Optoelectronics
1330 East Cypress St.,
Covina, CA 91724
Phone: (626) 967-9521 X 236
E-mail: [log in to unmask]
 

---------------------------------------------------------------------------------
DesignerCouncil 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 DesignerCouncil.
To temporarily stop/(restart) delivery of DesignerCouncil send: SET DesignerCouncil NOMAIL/(MAIL)
Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
---------------------------------------------------------------------------------