What is BGA or Ball Grid Array?

Ball Grid Array (BGA) is a type of surface-mount packaging technology that is used to attach IC components to printed circuit boards (PCBs). This type of packaging uses solder balls instead of regular leads to connect with the PCB. These solder balls are present on the bottom side of the IC package in a grid-like fashion and are soldered to the PCB through reflow soldering process. This type of packaging has more metal traces within the IC route connections from the silicon die to the solder balls, thus offering more I/O (input/output) connections compared to traditional packages, such as dual in-line or flat packages. The grid layout allows for high interconnection density and also provides better electrical performance.

BGA ICs enable shorter electrical paths between the die and solder balls with reduced resistance and inductance, supporting superior signal integrity for high-speed data transmission. Thus, this type of packaging is ideal for densely packed PCBs that have to meet high demands of signal integrity for fast processing and low-latency applications.

Types of BGA Packages 

There are several types of BGA packages, each designed to meet specific requirements. The following are the most commonly used BGA packaging: 

• PBGA (Plastic Ball Grid Array): This is the most popular type of BGA package used with double-sided PCBs. The core is made of bismaleimide triazine (BT) resin that is used as the substrate material. It can have 200 to 500 ball arrays, which makes it suitable for a number of applications.
• CBGA (Ceramic Ball Grid Array): It uses ceramic as substrate material and tin balls (ratio between tin and lead: 10:90) with a high melting point. The internal chip depends on Controlled Collapse Chip Connections (C4) which have excellent thermal conductivity and electrical performance.
• FlipChip BGA (FC-BGA): It is similar to CBGA in terms of structure but with BT resin used instead of a ceramic substrate, which is cheaper. It also has shorter internal circuit pathways, effectively improving electrical performance. The flip chip package has a ball grid made of tin and lead in a ratio of 63:37. 

Advantages of BGA Packaging

Due to their compact size BGAs allow for a smaller board footprint and are ideal for applications with space constraints. The shorter connection from the silicon die to the solder balls enables efficient electrical performance. BGAs are also highly efficient in terms of thermal management and thus help prevent the chip from overheating. They are known for their reliability as they are durable and deliver consistent performance in various applications. BGA packages strike an ideal balance between performance and cost which is why they are the most commonly used solution for most electronic devices.

Disadvantages of BGA Packaging

BGAs are difficult to inspect after soldering when searching for defects. The traditional optical methods may not be adequate and hence require advanced techniques such as X-ray inspection using expensive machinery. Reworking on BGAs is also more complex as they have more sensitivity; hence, reworking also requires precise handling and special equipment for BGA components. BGA components are also susceptible to environmental changes which means they need to be protected against electrostatic defects and carefully stored to assure reliability.