The carrier of TBGA is copper/polyimide/copper bimetallic layer, and the copper wire used for signal transmission is distributed on the upper surface of the carrier, and the other surface is used as the stratum. The connection between the chip and the carrier can be realized by flip chip technology. When the connection between the chip and the carrier is completed, the chip is encapsulated to prevent mechanical damage.
The vias on the carrier play the role of connecting two surfaces and realizing signal transmission. The solder balls are connected to the via pads through a micro-welding process similar to wire bonding to form a solder ball array. The reinforcing layer is connected to the top surface of the carrier by glue to provide rigidity for the package and ensure the flatness of the package.
Thermal paste is generally used to connect the heat sink on the back of flip chip, and the package provides good heat dissipation characteristics. The tin ball composition of TBGA is 90Pb/lOSn, which has been changed to SnAgCu after lead-free. The diameter of solder balls is about 0.65mm, and the typical solder ball spacing is. Omm, 1.27mm and1.5mm.
At present, the I/O number of commonly used TBGA packages is less than 448, TBGA736 and other products have been listed, and some large foreign companies are developing TBGA with I/O number greater than 1000. It is a surface mount package for multi-pin LSI, which is assembled on the front of the substrate (some BGA chips and leads are on the same side of the substrate).
Definition of BGA package:
The bottom surface of the whole device can be used as a pin instead of just the periphery, and the average line length can be shorter than the package type defined around, thus having better high-speed performance. Ball grid array (BGA) package is to make an array on the bottom of the package substrate, and solder balls are used as I/O terminals of the circuit to interconnect with the printed circuit board (PCB).
The devices packaged by this technology are surface mount devices. BGA(Ball Grid Array), abbreviated as BGA, can be translated into spherical contact array package, ball grid array or network solder ball array and spherical array. Spherical contacts are made as pins on the back of the substrate in array mode.