BGA technique (ball grid array package) that is, ball gate array packaging technology. The emergence of this technology has become the best choice for high-density, high-performance, multi pin packaging such as CPU, motherboard south, and North Bridge chips.
The area occupied by BGA packaging is relatively large Adopted a controlled collapse chip welding method so that its electrothermal performance could be improved. Addi - tionally the assembly of this technique can be weld coplanarly, allowing for a substantial increase in encapsulation reliability; And the encapsulated CPU implemented by this technology has a small signal transfer delay, and the adaptation frequency can be improved greatly.
BGA encapsulation has the following characteristics:
1. The number of I / O pins although increased, the distance between pins is much larger than the QFP packaging way, which improves the finished product rate
2. Although the power consumption of BGA is increased, it is possible to improve the electrothermal performance since a controllable collapse chip based welding is adopted
3. Small delay in signal transmission and greatly increased frequency of adaptation
4. Assembly can be welded coplanarly with greatly improved reliability
Inadequacies of BGA encapsulation: BGA encapsulation is still the same as QFP, PGA, occupied the substrate area is too large; The warping problem of plastic BGA packaging is its main drawback, i.e., the coplanarity problem of tin spheres. The criteria for coplanarity are to reduce warping and improve the characteristics of BGA encapsulation, and plastic, viscosupply, and substrate materials should be studied and optimized. At the same time, because of the high cost of the substrate, which makes it expensive.