WAVE SOLDERING PROBLEM - COMPONENTS are RAISED

[kuba]

Hello,

I have problem... PCB boards sometimes have raised components (esp.
connectors). I wonder if there is a solution for this. Maybe some
CLAMP ? I have tried a lot of possibilities.. I made clamp myself. I
put on connectors steel blocks. Nothing has finished with the
success.. Please, help me.

 

[Eeyore]

Hello,

I have problem... PCB boards sometimes have raised components (esp.
connectors). I wonder if there is a solution for this. Maybe some
CLAMP ? I have tried a lot of possibilities.. I made clamp myself. I
put on connectors steel blocks. Nothing has finished with the
success.. Please, help me.

When components are fitted in a position other than flush with a PCB they may
require additional mechanical support.

Please explain what information it is exactly that you want. What type of
components is/are giving you trouble ?

Graham

 

[DJ Delorie]

Have you tried smaller holes?

 

[J.A. Legris]

Hello,

I have problem... PCB boards sometimes have raised components (esp.
connectors). I wonder if there is a solution for this. Maybe some
CLAMP ? I have tried a lot of possibilities.. I made clamp myself. I
put on connectors steel blocks. Nothing has finished with the
success.. Please, help me.

It may be a problem with your flux and/or preheating. A raised
component is lifted by the surface tension of the solder wave and
properly fluxed components break through the surface tension and
settle down properly. The flux is activated partly during the
preheating phase. Contact the flux supplier for advice.

 

[kuba]

Thank you very much. I will contact my supplier of flux. Maybe that's
the problem. Size of holes is also too big I think I have problems
especially with 3-pin plastic connectors mounted on the PCB.

 

[J.A. Legris]

Thank you very much. I will contact my supplier of flux. Maybe that's
the problem. Size of holes is also too big I think I have problems
especially with 3-pin plastic connectors mounted on the PCB.

If they're extemely light you may have to hold them down with
adhesive. Also, try soldering one manually - some parts, such as old
stock that has corroded, are just about unsolderable.

 

[ChairmanOfTheBored]

It may be a problem with your flux and/or preheating. A raised
component is lifted by the surface tension of the solder wave and
properly fluxed components break through the surface tension and
settle down properly. The flux is activated partly during the
preheating phase. Contact the flux supplier for advice.

Great answer.

 

[ChairmanOfTheBored]

Thank you very much. I will contact my supplier of flux. Maybe that's
the problem. Size of holes is also too big I think I have problems
especially with 3-pin plastic connectors mounted on the PCB.

You can also squirt (drape) a bead of solder mask over the connector for
a temporary "stay". Remove right after wash, or it gets firmer with age.

 

[kuba]

You can also squirt (drape) a bead of solder mask over the connector for
a temporary "stay". Remove right after wash, or it gets firmer with age.

Hmm... I don't quite understand. Could you please explain it one more
time for me? I understood, that I must cover tips of connector with
tin solder. It's impossible to do this, because I work in very big
factory, and we cannot make this with each connector (( I know, that
we should buy special PCB carriers, but money money money....

 

[kuba]

If they're extemely light you may have to hold them down with
adhesive. Also, try soldering one manually - some parts, such as old
stock that has corroded, are just about unsolderable.

Thank you for this message, but I have question. Do you know which
exactly glue would be perfect for this problem? I'm not a glue-
specialist

 

[Eeyore]

Hmm... I don't quite understand. Could you please explain it one more
time for me? I understood, that I must cover tips of connector with
tin solder. It's impossible to do this, because I work in very big
factory, and we cannot make this with each connector (( I know, that
we should buy special PCB carriers, but money money money....

What he means (I think) is that some components should be hand soldered (after
wave soldering) to prevent them being moved in the wave solder process.

In order to do this you need to 'mask' the holes they fit into during wave
soldering with a compound he calls 'solder mask'. After wave soldering this must
be removed before it cures like an adhesive becomes tough to remove.

And yes. It costs MONEY and TIME to do the job right. If you want to save money
and do the job BADLY, that is your (actually the management's) decision. This is
why it's important to have good competent managers. An incompetent manager may
find a way to do the job on the CHEAP but it will never be a job done WELL.

Of course the reason you have about these issues is because clearly your
management IS incompetent or this problem would never have happened in the first
place. Sadly, today, most management is incompetent in my experience. The bosses
just want a 'yes man' more than they want a man who knows what he's talking
about.

Graham

 

[kuba]

What he means (I think) is that some components should be hand soldered (after
wave soldering) to prevent them being moved in the wave solder process.

In order to do this you need to 'mask' the holes they fit into during wave
soldering with a compound he calls 'solder mask'. After wave soldering this must
be removed before it cures like an adhesive becomes tough to remove.

And yes. It costs MONEY and TIME to do the job right. If you want to save money
and do the job BADLY, that is your (actually the management's) decision. This is
why it's important to have good competent managers. An incompetent manager may
find a way to do the job on the CHEAP but it will never be a job done WELL.

Of course the reason you have about these issues is because clearly your
management IS incompetent or this problem would never have happened in the first
place. Sadly, today, most management is incompetent in my experience. The bosses
just want a 'yes man' more than they want a man who knows what he's talking
about.

Graham

hmm... you are right. I will talk to my management... you are
absolutely right. In my opinion quality is more important than
quantity.

 

[kuba]

Does anybody know glue which will be OK for this purpose?

 

[Eeyore]

hmm... you are right. I will talk to my management... you are
absolutely right. In my opinion quality is more important than
quantity.

Are you confident your management feel the same ? Often they don't.

Graham

 

[Eeyore]

Does anybody know glue which will be OK for this purpose?

I think Loctite make some specific adhesives and the like for pcb manufacture.

Here are some examples of the 'solder mask/resist' needed to keep drilled holes
solder free (for later manual component insertion and soldering) during the wave
soldering process.
http://uk.farnell.com/jsp/search/br...earch_001&Ntt=solder+mask&Ntx=&_requestid=897

Graham

 

[kuba]

well....I have just talked to my boss. specialist of fluxing and
soldering. He said that there is no chance that flux is guilty. He
said that's bullshit ((

 

[Eeyore]

well....I have just talked to my boss. specialist of fluxing and
soldering. He said that there is no chance that flux is guilty. He
said that's bullshit ((

Indeed it's not the flux.

Why did you think it was ?

Graham

 

[kuba]

Indeed it's not the flux.

Why did you think it was ?

Graham

because of that:

 

[Eeyore]

because of that:

It wasn't me who wrote that but it has some value.

What occurs to me is that the surface tension of lead-free and leaded solder is
VERY different. Lead-free solders have poor 'wetting' ability. Maybe this is
your problem ?

Graham

 

[kuba]

maybe that's the problem. But I know, that when we used lead solder
there were also problems with raised components Maybe do you know
people working in similar factories than mine ? I want to contact with
quality engineers from factories producing pcb circuits.