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Solder Paste Problem (M705)

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#38504

Solder Paste Problem (M705) | 15 December, 2005

Hi Guys

I am new to SMT Line Currently having a lot of paste problem, have to change every 1.5 day after use. Please advice.

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Ooi

#38510

Solder Paste Problem (M705) | 15 December, 2005

What u meant by change every 1.5 day ( Expose to enviroment 1.5 day) ?

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#38511

Solder Paste Problem (M705) | 15 December, 2005

Hi I mean once I open the jar and load into the print machine, paste can use about 1.5 day and start giving a lot of problem.

I want to know how long it can be use in print machine.Please advise.

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#38512

Solder Paste Problem (M705) | 15 December, 2005

Welcome.

A day and a half seems like a very long time to leave paste on your stencil. We'd expect that the volitiles in the flux would have left the building in that time, making the flux less active. We start with fresh paste at the beginning of each shift.

You should follow the guidelines provided by your paste supplier [Senju].

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#38516

Solder Paste Problem (M705) | 16 December, 2005

A day and half is a life time for our solder paste, Almit V14L... but then we dont have in-line solder paste printers, we have micro BGA stencil that wont work with anything but new solder paste, 0.8mm pitch and pad size is 0.3mm, stencil thickness is 0.120mm, Flash gold PCB�s tin plated by manufacturer. I would suggest changing more often or using solder paste with slightly more flux content. What kind of sqeedgee�s do you use? do they re-cycle the solder paste for example holding the solder paste within the squdgee itself?

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trs

#38517

Solder Paste Problem (M705) | 16 December, 2005

Try to get a sample of Indium and give it a try......i happen to think its the greatest stuff since sliced bread!

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Rob

#38519

Solder Paste Problem (M705) | 16 December, 2005

How about keeping a fridge near the line and only putting on the stencil what is needed, then topping up from the jar as & when?

As soon as the paste hits the stencil flux will evapourate, and all of that time spent by people in labs developing complex multi-stage fluxes will be wasted.

So leave it on there for as short a time as possible.

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#38522

Solder Paste Problem (M705) | 16 December, 2005

Rob

The typical warming or stabilization time for solder paste is four to six hours. Check with your supplier for specific recommendations.

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Rob

#38524

Solder Paste Problem (M705) | 16 December, 2005

Hi Dave,

Sorry, blonde moment.

For our prototype line we decant the paste into a cleaned out pot, that goes under the printer hood, with the lid left on, the rest stays in the fridge until it starts to run down.

If we get it wrong we definitely don't steal paste from another line.

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#38561

Solder Paste Problem (M705) | 17 December, 2005

Hi Guys

My is in line system, printer DEK 265 stencil 4 mil only have to mount 20 components but giving me problem. After a month or so on this line still having paste problem about 1.5day need to change new paste. We are using whole jar 250g but doing manually stiring the paste before use. Do not know is the stiring having problem.

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