Everything You Need to Know about BGA Technology in PCB Assembly

BGA, which stands for Ball Grid Array, represents an advanced packaging technology utilized in SMT assembly. It is a notable achievement in the field of electronic technology, reflecting substantial advancements in packaging techniques.

BGA packages feature a multitude of spherical bumps on their surface, providing a vast number of interconnection points that enable the realization of high-density packaging objectives.

1. What is Ball Grid Array (BGA) on a PCB Board?

BGA integrated circuits are SMD components which do not have leads. Instead, they include solder balls which are an array of metal balls incorporated on the PCB. Fixing of solder balls of BGA on the PCB is done through a laminated substrate present at the bot of the PCB package board.

Metal traces are used to route die connections to the solder balls. BGA-PCB packages allow tremendous IO connections as compared to flat packages and dual in-line boards.

BGA ICs show more efficiency and high-speed performance due to shorter connections from the silicon die to the solder balls. With its compact lead length and generous lead space, the BGA package presents an excellent solution for high-speed PCB products incorporating densely packed circuits.

Stacking Process of BGA on PCB:

PoP: PoP (package on package) is used to stack the ICs and components of BGA on the designated package. This process is efficient for stacking multiple ICs on a single package e.g. packaging of memory/logic device with a processor.

2. What are the Types of BGA Packages?

1. PBGA: Plastic over-molded BGA made with a plastic-coated body, the laminated substrate of glass mixture, and etched copper traces. Ball pitch: 1.0 mm, 1.27 mm. 2-4 layered board of organic matter.
2. FlipChip BGA: it has a hard multilayered substrate on board.
3. CBGA: Ceramic BGA in which ceramic substrate is incorporated with FlipChip (FC) electrical connections.
4. CDPBGA: Cavity Down PBGA having square-shaped low depression in the chip area called cavity area.
5. TBGA: Tape BGA has a soft strip-shaped substrate with 1-2 layered PCB, also called Flex Tape BGA.
6. H-PBGA: High thermal BGA.

3. Advantages and Disadvantages of BGA

Advantages of BGA:

• Small-sized board.
• Efficient electrical implementation.
• High thermal dissipation.
• Efficiency and reliability.
• Cost friendly.

Disadvantages of BGA:

• Difficult inspection after soldering.
• Highly cautious and difficult rework may be required.
• The high sensitivity of BGA components to environmental changes.
• Need electrostatic protection and high storage maintenance.

4. Key Features of BGA

• Interconnection density and less board complexity due to PoP stacking.
• Cost friendly processing
• It prevents the chip from overheating due to lower thermal resistance.
• Low electric inductance.
• Less space requirement on board.

5. BGA Applications in PCB Assembly

Ball Grid Array (BGA) technology has become a cornerstone in modern PCB assembly, especially for products that demand high reliability and compact design. Compared to traditional leaded packages, BGAs enable more I/O connections within a smaller footprint, making them an essential choice in today's high-density electronic systems.

SMT Requirements for BGA Placement

To successfully assemble BGAs, manufacturers must follow strict Surface Mount Technology (SMT) requirements:

• Stencil design and solder paste selection: The stencil aperture size and solder paste viscosity directly affect solder joint quality. A uniform solder paste deposit is critical to avoid bridging or voids.
• Pick-and-place precision: BGA packages demand higher placement accuracy compared to other components. Misalignment can lead to hidden soldering defects.
• Reflow profile control: A well-optimized reflow oven temperature curve ensures proper solder ball wetting without overheating, which could damage the package or PCB.

Typical Applications of BGA Technology

BGA packages are widely used in industries where space efficiency and signal integrity are key:

• High-density motherboards: Laptops, servers, and gaming consoles rely on BGA-packaged processors, chipsets, and memory modules.
• Telecommunication equipment: Routers, base stations, and network switches use BGA devices for high-speed signal processing.
• Consumer electronics: Smartphones, tablets, and wearable devices benefit from BGAs’ compact size and improved thermal performance.

Key Considerations in BGA Assembly

Engineers must address several challenges during PCB design and assembly to ensure long-term reliability of BGA joints:

• PCB layout density: Proper pad design and via placement are critical to accommodate escape routing of BGA balls.
• Solder ball pitch: Finer pitches increase I/O density but also raise manufacturing complexity.
• Thermal management: BGAs with high power consumption require thermal vias and adequate copper planes to dissipate heat effectively.

By understanding these application requirements and design considerations, engineers can fully leverage the benefits of BGA technology while minimizing assembly risks.

6. BGA Inspection Techniques

Inspecting BGA packages is challenging due to solder ball placement. Traditional optical methods are inadequate for detecting defects. To improve accuracy, electrical testing, boundary scan inspection, and automated X-ray inspection are commonly used in SMT assembly with BGAs.

1. Electrical testing: This conventional method identifies open circuit and short circuit defects.

2. Boundary scan inspection: Leveraging the inspection port of the boundary scan design, this technique accesses each solder joint on the boundary connector to detect component opens and shorts.

3. Automated X-ray inspection:

Automated X-ray inspection examines solder joints under components, revealing hidden defects like voids and bubbles, unlike AOI, which only inspects visible connections. Common BGA defects include misalignment, loose solder, opens, cold joint, bridges shorts, cavities, missing/dropped solder balls, and irregular sizes.

7. How to Fix BGA Defects

Detaching of components: BGA component faults can be rectified by first detaching the components from the circuit board. It can be done by careful heating of localized components on board, which melts down the solder joints, and we can change the components and fix the solder connections as required.

BGA rework process:  BGA rework process is done in a dedicated rework station in the factory., where BGA-PCB components are heated through an infrared heater. Heat level can be checked by thermocouple. To raise the package from the underlyingboard a vacuum device is used along with other equipment.

Localized heating: the heating process is done very carefully and it is limited to the defect area on the board. Localized heating ensures the safety of neighboring components on the board.

JLCPCB BGA Technology

JLCPCB is widely recognized as a trusted provider of PCB manufacturing and assembly services, and offers BGA production as a key component of their comprehensive service portfolio. Their expertise lies in the production and assembly of PCBs that incorporate BGA packages. BGA packages, known for their advanced packaging technology, consist of a grid of solder balls that facilitate high-density interconnections. JLCPCB provides a highly efficient system of testing and inspection of the BGA-PCB products before finalizing and sending them to customers.

JLCPCB's BGA production services are specifically tailored to address the demands of contemporary electronics, ensuring that customers' diverse requirements for BGA integration into their PCB designs are met with utmost precision and quality.