Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Air Vac Mini Wave Process

Kevin Facinelli

#23173

Air Vac Mini Wave Process | 27 January, 2003

We have an assembly that requires a number of high density connectors to be placed after SMD. The process will not allow a normal wave solder setup due to the population of SMD comps. We cannot use a selective solder pallet due to profiles. We are looking to us an Air Vac mini wave to selective solder these connectors. We are concerned that we get good solder joints for the connectors. We are thinking of using our standard OA flux but concerned we may not have preheat to activate the flux. I am interest in hearing from people that have done a similar process and how they setup and what chemistry they used. The boards can be cleaned with a Aqueous batch cleaner after this process.

Looking for some good recommendations....

Thanks,

Kevin

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RDR

#23177

Air Vac Mini Wave Process | 27 January, 2003

i have done this thousands of times. You are correct about no preheat, however it never seemed to be any issue for us. You do have to make sure that you do not expose any SMT comps. to the solder or they will become heat stressed/fractured. Connectors dont really need to be pre-heated as far as the component goes. You will need to set your solder dwell time accordingly to burn off the excess flux and achieve good fillets. If you have the adjustable ramp-up/down you will be able to perform this process very well with minimal defects. The most trouble I ever had was with dross coming up in the nozzle. We fixed this by wiring up another potentiometer to ensure that the solder level did not drop down to 0 pump speed at the end of the cycle and maintained the solder to a level that it would continually drip out of the drains in the nozzle.

Hope this helps

Russ

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