I need to replace a broken planar circut (a Hall effect sensor) that was attached to a plastic hull of another unit (a rotor wheel assembly). And, most probably, will need to move the entire connector to a replacement assembly eventually.
The (remains of) the old circuit and its resting place look like this. The pads are thin copper. The whole depression was filled with some amber-like mass, remnants of which can be seen in the photo to the right (bonus points for any ideas what it might be).
Can someone explain how this connector was made, and how it's supposed to be worked on? For example:
- If I try to just solder the new circuit in, I'm probably going to melt the underlying plastic in the process
- It's unclear how whoever made this was able to place the pads by hand with such precision (the IC's size is 2x5 mm). This is clearly not any kind of printed design.
Looking around the Net found plenty of guides on soldering surface mount components, but nothing on non-PCB placement or dealing with a melty surface.
Photo from the side with all the amber-like mass removed: