View Bga Package Soldering Pictures. Bga ics having 4 pins to this smd package employs an array of metal spheres that are made of solder called the solder balls for. When bga balls melt down they collapse and the bga sinks down a little bit, with the time you will get experience and will notice this collapse to be sure when the bga balls are really soldered. I've found that bga balls actually melt.

I've read that some say that it's advised to add some paste, some say to add flux and some say just to put the chip in place.

Substrate used for bga packages having high heat resistant thermosetting resin of the additional. Array of chip solder balls requires a fine via grid on the top surface of the bga. Solder pastes, microstencils and microsqueegees have been developed to correspond with multiple bga sizes and ball array footprints. 8.1.5.1 ball grid array packages. It is the solution to 2.wellpcb bga capability & service. The underlying metal surface to be wetted by solder. High bond strength, ph value neutral, insulation is strong, welding surface smooth. 3.3.3 notes on bga package reflow soldering.