[glenfraser]

Proberly posted this in the wrong place but i am sure admins may stick it someware else etc....

Right so we have all built, or about to the cnc pcb(printed circuit board) drilling machine. GREAT

But now what about the pcb tinning machine. Something i would like to try but havnt got a clue how to do. Hours searching for a cheep second hand one. No luck.
Hours searching for any info on how one works or how to build one. No Luck.

So i turn to you guys to see if any of you no how to build one.
How does the rollers heat up ?
Were do we get cheap rollers for this.
Anyone got any designs ?

Dont mine a hand turned one but havnt got a clue how to start about making one.

Any help from u guys is welcome.

Glen

[ToMMY2ooo]

Tinning is (or at least can be) a chemical process.

Cheers,
Tom

[glenfraser]

Yes i have done it this way but would like to do it with a machine instead of using the tinning xtals....
Glen

[Tonton75]

Yes i have done it this way but would like to do it with a machine instead of using the tinning xtals....
Glen

Hello ,

I decided like you to undertake the construction of a machine .
Below the image of a small machine of mark CIF (French) of which you can be inspired to construir your .
Since september 2004 had progressed you?

Cordially
Tonton75
Sorry for my bad English !

[ElectronicsEng]

Roller tinning is not difficult, at least not for small volumes.

The solder is heated in a tank, or bath, which is usually heated electrically. A metal roller (usually steel I think) is immersed in the solder and a temperature resistant slightly compliant roller abover the PCB is used to apply pressure and guide the PCB through the slot.

The PCB needs to be well cleaned before it is coated. Flux needs to be used and can either be brushed or sprayed onto the board or applied to the solder in the bath. The roller coating process will leave 'dags' all over th eplace usually. So the board then needs to be cleared, usually by using a hot air 'levelling knife' or reflow process.

But to be honest, if you are only building boards for yurself, why do you need to solder coat them? Why not just clean and flux coat? There are plenty of really good fluxes around now (have a look at the Ketser web site).

John

[Tonton75]

Roller tinning is not difficult, at least not for small volumes.

The solder is heated in a tank, or bath, which is usually heated electrically. A metal roller (usually steel I think) is immersed in the solder and a temperature resistant slightly compliant roller abover the PCB is used to apply pressure and guide the PCB through the slot.

The PCB needs to be well cleaned before it is coated. Flux needs to be used and can either be brushed or sprayed onto the board or applied to the solder in the bath. The roller coating process will leave 'dags' all over th eplace usually. So the board then needs to be cleared, usually by using a hot air 'levelling knife' or reflow process.

But to be honest, if you are only building boards for yurself, why do you need to solder coat them? Why not just clean and flux coat? There are plenty of really good fluxes around now (have a look at the Ketser web site).

John

Ok,


Thank you for the answer, but my question more particularly relates to the detail of the realization of a machine. I already used the chemical method (too thin layer, produces expensive) as well as the method of coating (hard, lack of uniformity of the layer).
The process of coating to the machine remains most professional.....
The problem for a ` amateur' it is the price even for a small machine.
Thus if somebody already produced such a machine, I am taking of all information.

Cordially
Tonton75

[philba]

A simpler/cheaper way to tin is to use diluted solder paste and "reflow" it. You can use plumbers solder paste which is fairly cheap and an electric skillet ($30 from target or about 5 from a thrift store).. Put the paste on thinly and then heat it up in the skillet. The thin solder paste won't bridge and won't stick to FR4. You might have to do several applications to get the right thickness.

[Chris D]

A simpler/cheaper way to tin is to use diluted solder paste and "reflow" it. You can use plumbers solder paste which is fairly cheap and an electric skillet ($30 from target or about 5 from a thrift store).. Put the paste on thinly and then heat it up in the skillet. The thin solder paste won't bridge and won't stick to FR4. You might have to do several applications to get the right thickness.

I use a similar process too - only I heat it with a heat gun - works great!

Chris

[greybeard]

I've not come across this product in the uk.
Do you get the paste ready-thinned ?
If not, what do you dilute it with ?
John

[philba]

I believe it is water thinnable - go to http://www.mcmaster.com/ and search for "solder paste". scroll down about half way in the results for "solder paste with flux" 7683A4 is "ideal for tinning" according to their info there. (sorry, tried to link to the results page but it didn't work) You could use the Pb-free stuff but you'll need more heat and it's quite a bit more pricey. Can't help you on UK availability.

And if you have a hot air machine/blower, that's just as good as the hot plate approach.

Phil

[Tonton75]

Hello !

I began construction from my machine to be galvanized. The first part the stainless roller... To follow.....

Tonton75

[neazoi]

I have tried all chemical methods above. Tinning crystals solution or plumpers heating pastes. All of them look proffessional at the beginning but they are crappy. The tinning crystals solution oxidizes by the heat of the iron and also after some weeks. The plumpers heating paste is too hard to remove after curing and the lead-free solder does not stick to it easily. As I said these are crap!
The only reliable and long term solution to tinning is tin copper with "real" solder. This can be done with the iron or proffessionally (and better) with the roller tinning machine.
I remember how fast and reliable tinning was with such a machine back in the university lab.

Nevertheless, when making microwave PCBs in teflon laminates, it is not suitable. Bare copper there usually not tinned at all, or tinned lightly with the crystals tinning solution.