PCB wave soldering problem_Solder shorts, Dry-joints,etc...

wave soldering component

Facing huge quality problems regarding PCB soldering in our factory.
Can anyone help to guide me: PCBA wave soldering effects simulation machine (based on actual PCBA) or software (based on PCB CAD data)?

wave soldering accepted dfm points

while doing PCb designing you should consider some important points if your are going to do wave solder.

All the caps should be perpendicular to the machine flow direction.

all caps should not be under the shadow for height components.

100 mils distance should be maintained from height components.

by this you can rectify all the major problems

hope this will help you

cheers,
chak

wavesoldering issue

chakravarthy80pcb said:

while doing PCb designing you should consider some important points if your are going to do wave solder.
All the caps should be perpendicular to the machine flow direction.
all caps should not be under the shadow for height components.
100 mils distance should be maintained from height components.
by this you can rectify all the major problems
hope this will help you cheers, chak

Click to expand...

I am impressed with your sugession. You have nice knowledge in PCB designing. Good luck. Keep it up.

soldering wave forum

Hi

As we are using IPC 7351 calculator for footprint creation with nominal settings though we have minimal and maximum settings in the calculator.

As per discussion,i have one doubt here.Do we need to change the footprints based on soldering requirments(Wave/Reflow) ,if we use 7351Cali

In IPC782 ,it was giving different footprints based on Wave/Reflow

plz guide me.
Abhishek

dry soldering

hi abhi002

ipc 782 in1996 reflow pattern..

ipc7351b is latest 2009 updated version...
i am also using footprint calc from pcb matrix.....

if u r using reflow pattern no prob...but ur going to flow soldering process must u should go to any another dimns...or

Added after 11 minutes:

i think no standards for flow soldering footprint pattern.we are assuming our experience .


if any standards is there pls ask me......its very helpful for me.

wave soldering problems and solutions

Just changing your footprints wont completely cure it, footprints are not the answer to everything.
(although they often get blamed - it can often also be found to be something else).

You need to also look at the wave machine profiles, fluxing, temperatures et all.

Have you got a trained & really experienced operator running the solder wave machine?
Is it cleaned regularly & is your solder uncontaminated?
Have you got the correct flux for the board, the correct solder & are you running the correct temperatures for that solder?

chakravarthy80pcb's suggestions are good & should be followed however there are still many more considerations to preventing bad joints when wave soldering the boards.

Can you provide close up photo's of the problem components/joints etc?

circuit board dry joints

Thanks for all of you guys replies and suggestions.
However, we do know about wave soldering problem solving techniques. But the problem with that, it is on a trial and error basis (case to case basis). What I require is more onto upstream solutions from PCB design. As such I am looking for any simulation machines or software programs that could make predictions before the actual PCB been released to Factory.

I hope you could help

Ronnie

what is dry soldering

so far there is not a software tool could simulated a result of you pcb design throughout wave oven.

but you can improve you design of pcb library .

soldering pcb on top of pcb

Hi Cyberrat,

Thanks for reply.

As a PCB design engineer,my control is on footprints and other PCB design processes.I can easily modify the footprints and placements as per the soldering requirements ..so that there should be any issue while assembly.
But to go for skilled technician and good setup is not in my hand and Also its cost related issue which is i feel most of the companies won't agree.
Anyway it was nice chat all you experts.

Thanks a lot

dry joint solderabilyt problem

Abhi, dont get me wrong, there is a 100% need for the design engineer to do the designs based on best manufacturability (DFM) and to ensure that all footprints that are used in a Wave soldering machine are suitable for it.

However a lot also relies on the competence of the wave machine operators, in the past I have seen absolutely no problems with boards with what can only be described as "pads bad for wave soldering" being sent through the wave with absolutely no problems because the operator knew what he was doing and how to run it through, but on his days off we get complaints from his supervisor saying the pads must be too small.

Hence my suggestion.

So yes, ensure your libraries contain wave only footprints, your boards are designed with wave flow, shadowing, and all the other stuff in mind - you ensure you do your bit.

But you "may" still get problems on the shop floor and guess who they blame....... the designer - he must have designed it wrong.

If a company will not employ a skilled operator of such a high spec machine then they are losing out, the costs of fixing the faults will far outweigh the cost of a decent operator.


Such is life... we do our best but still get bitten on the ass...