Hello there, I just want to ask you how often do you take your profiles on the Reflow Oven and Wave solder? I have a HMLV line running 5-6 products per shift (Reflow Oven & WS) my tech spend too much time checking the profile, but no major differences found, I guess it is Ok to check profile once a day for each process, what do you think? I will propose to the team to conduct a verification just once a day based on the fact that profile is "identical" each time I checked.. does it make sense for you?
Once a day is excellent QA but my experience has been that it's overkill. We check various products at the start of the run - it amounts to a couple of times per month at most. Over the years, I have not seen any problems with the ovens. The only changes I have to make to recipes are related to time of year as it can get hot in the shop during the summer and relatively cool in the winter which forces us to make minor adjustments to the ovens to accomodate for ambient temp. changes - never more than a few degrees here and there. I would say the only reason to do it everyday is if your customer demands it or if you are having problems with an oven or recently fixed one and want to watch it close until you are certain it's O.K. If you have to get out of a running recipe and load a specific recipe with a dedicated profile jig or PCB for your checks, you will see variation in profiles just based on how much time you have to let the oven stabilize and that would be wasted time and not reliable information.
You should just be running you Kic or Mole to verify the process.Every new board should be profiled. Once have verified the process there should be no reason to keep prifiling the boards. Your QA dept should be inspecting the solder joints. If there is a solder issue then you should go back to the KIC. If your oven looses a fan the zone will still read the correct temp, but the fan will not blow the air through the zone. You will never know this is happening until you run your KIC. Having said this you will see defective solder joints. You should trun on your oven once a month in a warm up mode. Open the cover and make sure that your blower fans are running in each zone.
we encounter the same problem as you 3 years ago. but now we have implement to use KIC 24/7. you just need to take 1 time profile (for the base line profile), and then for the next time you run your product, it will take profile for each board you build virtually.
KIC 24/7 has evolved into RPI. Not only will it give you virtual profiles, it also gives you DPMO and yield, based where each board lands in the process window. The good thing about this software, you can go back a year later and look up a specific serial number and be able to print out the profile that specific board saw. Very useful when your customer has a field failure.