BGA assembly (Ball Grid Array Assembly) plays a vital role in chip design PCBs for placing BGA (Ball Grid Array) components. BGA assembly is used for complex PCBs. It uses a fine pitch assembly method to place BGA components on the components. BGA offers customers low assembly cost and excellent density.

Basically, BGA assembly is one of the best ways to place ball grid components on PCBs using automatic reflow soldering. BGA is a surface mount component that has multiple ball arrays to provide connections to the PCB. LGA is a similar part of BGA. LGA is a pad grid array that has square ball arrays on it to make connections on the PCB.

What is BGA?
BGA is a surface mount component that is used for chip design ICs. The full name of BGA is ball grid array. Therefore, it has many balls in the form of an array. Generally, BGA is used for chip design PCBs such as microprocessors and integrated ICs. That is why ICs and processors require a permanent solution to mount any PCB. Because these chips and processors are used in computers, RAM, laptops, etc. Therefore, BGA is the best solution for the future due to its high density. BGA components are placed using only automatic pick and place machines and soldered using reflow machines. Because they are difficult to rework. That is why sometimes customers require additional inspection of BGA parts.

BGA Package Types
Plastic BGA
Ceramic BGA
Tape BGA
Enhanced BGA
Metal BGA
Micro BGA
BGA Assembly Process
Stencil Creation and Inspection: First, a solder stencil is created and inspected for solder joints and unwanted solder paste by a solder paste inspection machine.

BGA Placement: After creating the solder paste, these PCBs will be picked and placed by a machine to place the BGA components on the PCB.

Reflow Soldering: The BGA PCBA is placed in a reflow oven to heat the solder and place the parts correctly on the pads.

Cleaning and Inspection: After the reflow soldering process is over, the PCB needs to cool the solder. Usually, BGA PCB assembly prefers no-clean assembly. Sometimes cleaning is required, then BGA PCBA should be cleaned as required. The assembled circuit board uses different inspection methods to check whether the solder joints are correct.

Critical Factors of BGA Assembly

Baking Procedures
Due to the packaging of BGA components, some baking procedures are required during the production process. Basically, BGA is packed in plastic bags and packaging bags. Therefore, it absorbs moisture. That is why it needs to be baked at a low temperature to remove moisture and air cavities.

Precautions for Solder Paste Printing
As we know, BGA has many solder balls arranged in an array. Basically, these solder balls have some specific fine pitches such as 0.05 mm, 1.27 mm, etc. Therefore, more precautions need to be taken during solder paste printing. If the right solder paste is not used, then there will be short circuit problems and misalignment may occur.

Pressure in BGA Mounting
BGA components are placed on the PCB using a mounter. This mounter has an outlet for mounting them on the PCB. Therefore, this outlet uses some pressure to place them on the PCB. Sometimes placing BGA on PCB may require a lot of pressure, and then BGA will suffer some manufacturability impact.

Specific Reflow Temperature
BGA is placed on PCB using reflow soldering process. Reflow soldering requires a certain temperature to melt solder to connect the ball with PCB. Sometimes BGA will be affected by the temperature of reflow oven. Therefore, most customers will provide a specific temperature for BGA, which is used in reflow oven.

Solder Joint and Performance Inspection
Due to the performance of BGA components, they will not be used again on PCB. In addition, BGA components are difficult to rework. Since BGA solder balls are small, rework takes more time. PCB assembly BGA requires more methods to check solder joints and their performance.

Via-in-pad method for BGA assembly
When you place BGA assembly order, please use via-in-pad method for ball grid array assembly because BGA has fine pitch. Therefore, PCB assembly BGA will be beneficial.

No-clean solder paste
Compared with no-clean solder paste, BGA assembly is more suitable for solder cleaning.

Quality inspection of BGA assembly

AOI and manual inspection
We can use AOI and manual inspection to inspect BGA connections. AOI and manual inspection methods are used to find bad solder joints, solder joint shorts, and other types of errors.

X-ray inspection
Automatic X-ray inspection machine can inspect the entire BGA component, solder joints, solder joint voids, solder bridges, BGA component misalignment and shorts. These types of errors are usually visible on the PCB. Therefore, X-ray inspection is easy to find. Some customers want X-ray images of BGA assembly.

Electrical test
We can verify BGA assembly short and open errors using electrical test methods.

BGA assembly advantages
High reliability
BGA components have solder balls for electrical connections. We can easily solder BGA components to pads. Therefore, BGA assembly provides high reliability for placing BGA components on PCBs.

Excellent Performance
BGA components have very tight solder ball pitches due to their small pitch. The solder balls are very closely spaced and form a strong bond with each other, so excellent performance can be achieved.

Thermal Management
BGA parts have heat lines that eliminate overheating of chip ICs. Therefore, BGA components are more effective in preventing overheating, which is beneficial for improving the thermal resistance of PCBs.

High Compactness
BGA parts are small in size and occupy less space on PCBs. Therefore, BGA components provide high compactness for PCBs.

Disadvantages of BGA Assembly

More Inspections
BGA components have BGA parts that have tiny solder balls for soldering. So, are these solder balls done correctly? That is why component suppliers use more inspection methods to check various errors in BGA components.

Costs
Many BGA parts are cheaper, but some are more expensive. Generally, chip-designed BGAs are more expensive in the electronics market. Moreover, these chip-based BGAs have higher rework costs.

More Precautions
BGAs are very sensitive parts. Therefore, we need to take more precautions about BGA components and their storage requirements. Therefore, BGA assembly is quite difficult for bulk orders.

After thoroughly checking everything about BGA assembly, we need to look at BGA assembly instructions, pros and cons before placing BGA components on PCB. It is good for us. If you don’t know the requirements, it is a waste of time for all of us, including assembly suppliers and manufacturers. As we all know, BGA assembly is used for chip ICs and processors. Therefore, refer to the fine pitch in PCB design for routing. In addition, create stencil and mask patterns according to BGA assembly.