Hi all,

When soldering SMD components, it is a bad practice to leave the pads visible (as shown in the photo below)?


Also, is it normal for high temperature solder not to be shiny (as shown in the photo below)?

Are these solder joints any good, or will they cause intermittent problems?

Thanks in advance.

 

Unless the pad-plus-solder is being relied on as a heatsink I see no problem with the pad not being totally covered in solder.
Lead-free solder joints may be dull. Don't know about high-temp solder joints.

 

Hi temp solder is ugly looking, never bright smooth joints like the time tested 60/40 tin lead solder makes.

 

Are these solder joints any good

Most of them look like they have too much solder.

If oxidation is limited to the surface, it won't be a big problem.

 

Thanks for the replies. The first and last photos look ok, although the finish is not shiny. But is the solder joint shown in the second photo normal? its eggshell surface does not give me the impression of a good solder joint.

 

How To Solder SMD resistor Using Solder Paste.

 

Hi all,

When soldering SMD components, it is a bad practice to leave the pads visible (as shown in the photo below)?
View attachment 110795

Also, is it normal for high temperature solder not to be shiny (as shown in the photo below)?
View attachment 110797 View attachment 110798 View attachment 110800
Are these solder joints any good, or will they cause intermittent problems?

Thanks in advance.

One school of thought suggests if the components are too well soldered, thermal expansion can cause fractures - the opposite view is that the fractures will happen in the solder if the fillets are a bit thin.

Moderation is the name of the game, like anything; there's always compromises.

Some of the solder in the image looks a bit thin, but I'd examine closely with light an magnifier, and only fix the ones that are broken.

The definition of "broken" is any evidence of hairline fracture.

Lead free solder usually looks like dry joints anyway - so that isn't necessarily a criteria.

 

The joints in the second photo look slighly cold. Make sure that you use adequate flux when creating the joints.

Why are you using high temp solder?

Is that a gold finish on your pads? If so, what is its thickness?

 

The SMD would be considered "insufficient wetting" by the IPC A-610 standard.