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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Lead free selective solder

Views: 834

#77909

Lead free selective solder | 23 June, 2017

We are having issues with top fill and dropping pins on Molex connectors with our KISS 101. Unfortunately we do not have a pre heater and bottom side pre heat with our nozzles is not satisfactory. Most of the issues occur when using a no clean process. We are a contract manufacturer and runtime is a critical factor.

This is my first experience with lead free solder using this equipment. Any recommendations?

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#77912

Lead free selective solder | 23 June, 2017

Try add a pre-heater. If not change the process or the machine. With KISS you will hardly get any PCB to work properly.

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Tim

#77950

Lead free selective solder | 24 June, 2017

You will need to preheat the boards for a lead free selective solder process. A preheat module is critical for any wave or selective solder process, if you don't get the board preheated properly the solder is going to resist flowing to the top of the PCB.

The best option is to get a machine with a preheat module but there is the cost factor with this. For lead free my company uses a ERSA Versaflow 3 machine and we have had great results with both no clean and water soluble fluxes.

Another option is if you have a oven that you bake your boards in you can try to take a board directly from that oven and put it in your machine, this is a bad process but it might work if you only have one lead free assembly to run.

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#78018

Lead free selective solder | 29 June, 2017

HOW THICK IS THE BOARD?

IS THERE A LOT OF COPPER IN THE BOARD?

DOES YOUR CUSTOMERS PROVIDE HEAT RELIEF IN THE BOARDS BARREL DESIGN

THERE NEEDS TO BE PLENTY OF ROOM FOR LEADFREE SOLDER TO FLOW, DID YOU CHECK YOUR PIN(LEAD)TO HOLE (BARREL) RATIO?

NO PREHEATER, CAN YOU PRE-BAKE YOUR BOARDS? BE CAREFUL OF OTHER COMPONENTS

THICKER BOARDS (THICKER THAN .062") WITH HEAVY GROUND PLANE ARE CHALLENGING PREHEAT AND TO FLUX.

IS THE FLUX FILLING THE BARREL?

TAKE A BARE BOARD OR THE SOLDER SAMPLE OF THE BOARD, WITHOUT PARTS. PLACE A SHEET OF PAPER ON THE TOPSIDE, RUN THE BOARD THROUGH THE FLUXING/SOLDERING PROCESS THEN CHECK THE PAPER. THE PAPER SHOULD BE WET WITH FLUX LETTING YOU KNOW YOUR SPRAY FLUXER WORKS WELL AND FLUX IS MAKING IT TO THE TOP OF THE BARREL

ANOTHER WAY TO CHECK IS TO APPLY A DROP OR TWO OF FLUX FROM THE TOPSIDE INTO THE BARRELS IF THE SOLDERING IMPROVES YOUR SPRAY FLUXER COULD BE THE ISSUE

DROPPING CONNECTOR PINS, I THINK IT COULD BE RELATED TO TOO LONG OF A DWELL TIME OVER HEAT

I HOPE THIS HELPS :)

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Reflow Oven

PCB machines