washing miss-printed boards

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Hello experts, I wonder if you have any recommendation rega... - Mar 17, 2018 by Diego

1. Use ultrasonic cleaner after you manually wipe out the ma... - Mar 19, 2018 by Evtimov

I agree with the other comment, if you have misprint somethi... - Mar 21, 2018 by Armando_Gomez

Also, get your PCB suppliers to send you BBT failures that t... - Mar 22, 2018 by Robl

Thank you guys. And Yes, the process and knowhow of the team... - Mar 22, 2018 by Diego

Hi Diego, Yes, we use a low tack Polyethylene tape, 300mm... - Mar 23, 2018 by Robl

Diego

#79994

washing miss-printed boards | 17 March, 2018

Hello experts, I wonder if you have any recommendation regarding reducing the boards needs to be washed out.... it is mainly generated due to first miss-printing after each Production Order setup.... but since board washing is a very manual process, I can not confirm that it will clear all residue from it.

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Evtimov

#80008

washing miss-printed boards | 19 March, 2018

1. Use ultrasonic cleaner after you manually wipe out the main amount of solder. 2. Ask yourself why you have misprints so often. I work in this industry for 20 years and can't recall having many misprints. Something in your process should be fixed. Good luck!

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Armando_Gomez

#80040

washing miss-printed boards | 21 March, 2018

I agree with the other comment, if you have misprint something is wrong with the screen printing process, meanwhile try to get a ultrasonic cleaner for your boards, another thing you can do is to use dummy boards, if you don't have a lot of different boards, use one to test the screen printer before to run, this way you can fix the problem and then run, but I think you first need to check you printer.

cheers!

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Robl

#80046

washing miss-printed boards | 22 March, 2018

Also, get your PCB suppliers to send you BBT failures that they would usually throw in the bin. In addition to print testing you and use them for profiling.

We use a sticky film for print testing, then wipe, peel off and throw in the bin.

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Diego

#80050

washing miss-printed boards | 22 March, 2018

Thank you guys. And Yes, the process and knowhow of the team has a lot to be worked on, but Work Orders are of 5k to 10k units, so miss-printings will occur everytime that the printer is setup at the very least.

I wonder if you have a PCB washer to be used closer to the production line in order to use this method of dummy boards.

Also Rob, what do you mean by sticky film? Do you print over a thicker board (board+film) and then inspect the printed sticky board in SPI?

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Robl

#80054

washing miss-printed boards | 23 March, 2018

Hi Diego,

Yes, we use a low tack Polyethylene tape, 300mm wide in reels of 250m. It's about 75 micrometers/ 0.075mm / 0.003", although we are looking at going down to about 0.06.

Not all boards go through SPI, some just go through 2D - depends on the quality plan and build standard.

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