Hello all,
I have been desoldering some components from an old CRT TV recently, and I ran into a type of solder joint I've never seen before. You will notice a "flower pedal" pattern on the joint. This was revealed after removing most of the solder from the joint. I have been unable to find a reference to this type of connection online.
The following is total speculation.
I think this could be some sort of riveted connection that was added for support or to prevent easy removal of the component. What I'm imagining is something similar to the "copper rivet" image I attached, except that it's small enough to fit inside the component hole, and is slotted at the bottom. The manufacturer would flatten out the rivet on the bottom side of the circuit board during construction of the board. This could explain the "flower pedal" pattern observed on the "unknown solder joint" image.
I have attached images of the type of joint from above and below. Also, I have included an image of a copper rivet, which I am imagining being inserted in the component hole.
Thanks in advance to anyone who corrects me or has any more information on this.