How exactly are the connections made between the layers of a multilayer circuit board.
Looking at the holes of one of the bad boards, through a microscope almost looks like a rivet was used.
Solder at this failed connection refused to bead at the base. At closer inspection i noticed that the metallic ring around the hole was missing. The connection looked strange in another way; what i first assumed was solder formed itself into a perfect tube inside the resin board.
Looked like this:
Is there a brass rivet/tube that connects the outside layers of a multilayer circuit board. Is this what the capacitors are soldered to?
This is a board that i got from ebay for $4.95 that appeared as though it had been factory re-capped before. It was covered with known-bad capacitors that were incorrect (higher than) values from similar boards that i own.
There was no memorable 'event' when the solder ring went missing. I don't know if maybe the tube shape, and the damage, was caused by the fact that a dental probe was used to clear the hole of solder. The solder ring could have also been pulled off by soldering braid but i think i would have felt some kind of momentary resistance when removing the braid.
Does solder alone connect the pads on opposite sides of the circuit board?
.
Looking at the holes of one of the bad boards, through a microscope almost looks like a rivet was used.
Solder at this failed connection refused to bead at the base. At closer inspection i noticed that the metallic ring around the hole was missing. The connection looked strange in another way; what i first assumed was solder formed itself into a perfect tube inside the resin board.
Looked like this:
Is there a brass rivet/tube that connects the outside layers of a multilayer circuit board. Is this what the capacitors are soldered to?
This is a board that i got from ebay for $4.95 that appeared as though it had been factory re-capped before. It was covered with known-bad capacitors that were incorrect (higher than) values from similar boards that i own.
There was no memorable 'event' when the solder ring went missing. I don't know if maybe the tube shape, and the damage, was caused by the fact that a dental probe was used to clear the hole of solder. The solder ring could have also been pulled off by soldering braid but i think i would have felt some kind of momentary resistance when removing the braid.Does solder alone connect the pads on opposite sides of the circuit board?
.
That makes a strong argument against the use of a dental pick. (or any other mechanical method for removing solder)
.
.
Comment