Hi team! I agree with Bhanu, having a fixed number requires established processes and material sets to be safe and even then, there is risk. Our current procedures allow for 3 reworks before a process/design team consultation/review is required. Dave Hillman Rockwell Collins [log in to unmask] On Wed, Mar 28, 2018 at 1:03 PM, Bhanu Sood <[log in to unmask]> wrote: > Rework or scrap? the risk is usually assessed by weighing in the laminate > type (PI, FR-4, flex etc), design, board stack-up, components in vicinity > of rework site and time/temperature required for each rework (including > preheat). > > > Any guidelines regarding the number of allowable reworks are going to be > specific to a design/material combination, tricky to extrapolate that > guidance into a standard…rework risk assessment needs to analyze all > factors and be better understood with solid research. Most companies say a > site can be reworked 2 or 3 times (assuming high Td/Tg PI...$$$). > > > > On Wed, Mar 28, 2018 at 1:40 PM, Nutting, Phil <[log in to unmask] > > > wrote: > > > Respected colleagues, > > > > I was just asked a question to which I could not put a number. > > > > In the case of needing to fix a circuit board "right now" to fill the > > income stream there should be a logical point at which the reworks have > > become too extensive for production boards beyond the "right now" need > and > > the board should be revised to eliminate the reworks. > > > > Is there an IPC or MIL standard that suggests a limit on the number of or > > amount of rework allowed on a circuit board before it should be revised? > > > > > > Phil Nutting | HVP Senior Development Engineer | Excelitas > > Technologies Corp > > > > Lab: +1 978.224.4332 | Office: +1 978.224.4152 > > 35 Congress St, Salem, MA 01970 USA > > [log in to unmask]<mailto:[log in to unmask]> > > www.excelitas.com<http://www.excelitas.com/> > > > > > > [Excelitas R_emailsig] > > > > > > Please consider the environment before printing this e-mail. > > ________________________________ > > This email message and any attachments are confidential and proprietary > to > > Excelitas Technologies Corp. If you are not the intended recipient of > this > > message, please inform the sender by replying to this email or sending a > > message to the sender and destroy the message and any attachments. Thank > > you. > > > > > > -- > Bhanu Sood > Tel: (202) 468-8449 >