I really echo Warren's message. When first developing HP's BGA rework
process, using SRT, it took three months to get everything almost right.
Then, there were surprises needing rectification. It never really ended as
new boards and components were designed and built plus CPI.

The process first must be developed. It must be transferred to manufacturing
including all procedures for everyone and all parts involved, or those
perceived to be, it must be validated for each part on each board type, and
operators must be trained for each shift. Though most all operators great at
their jobs, some definitely caught on quicker and did consistently better
jobs than others.

Profiles alone can take much development time, and they're long themselves,
no matter the paste or original assembly profile. Parts must be removed and
sites cleaned and touched up and thoroughly inspected. A costly supply of
nozzles must be bought as well. Micro stencils must be purchased and
processes developed for their use. Part replacement and reflow processes
must be right on. X-ray inspection is a must for rework, as it is for
prototypes, before final test, and on it goes.

This is a good one to "farm out." I think you already knew this or are an
excellent rework engineer yourself.

MoonMan

---------------------------------------------------------------------------------
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
---------------------------------------------------------------------------------