With ever-increasing smartphone prices, repair and rework options are often a good financial choice for both manufacturers and consumers. As such, the ability to solve simple connection problems with a ball grid array (BGA) rework station is an increasingly popular solution. BGA rework stations offer solutions from upgrades to fixing faulty parts and assemblies all with a 60% to 90% success rate.

The Evolution of BGA Rework Machines

BGAs are favored for their advantages in density and yield, which are some of the reasons that they have become a popular choice for mobile devices. However, the same features that make BGAs favorable in technology make them difficult to rework. Solder bumps are hidden from view on a BGA, making visual inspection practically impossible, and the solder cannot easily be altered to fix mistakes. As such, rework requires removing the solder through the application of heat and starting fresh.

At its core, a BGA rework station is a designated workspace that technicians use to alter PCBs with BGA packaging and surface mounted devices (SMDs). Also called SMD rework stations or surface-mounted technology rework stations, BGA rework stations historically consisted of a machine that simply blew hot air onto the board. The goal of these methods is to heat up a portion of the board to the right temperature so that the solder melts from the board. In very small-scale situations, the same thing was accomplished with a common heat gun.

While these early rework stations accomplished their goals, they were prone to errors. Users had to hold the hot air applicator in place over the board, which left room for human error and the potential for the board to get over-heated. Early stations also had limited nozzle sizes to blow hot air, which meant that more of the board was heated than intended. Additionally, the solder could easily fall from the board and roll to the floor, posing risks if the solder is lead-based. To combat these issues, industry professionals developed more sophisticated BGA rework stations.

Over time, BGA rework stations evolved to become all-in-one machines specifically for rework. In addition to the hot air rework method, infrared rework stations were also developed as an alternative. Both methods are available in a range of solutions, from the traditional hand-held method to all-in-one stations that hold a board in place. Stations can also come with options to apply heat to the top and bottom of the board for more targeted application. Some stations are fully self-contained with their own internal air and vacuum systems, as well as areas to trap solder as it falls from the board.

BGA rework stations have become increasingly advanced over time, and have further developed with the evolving industry. Today, BGA rework stations for mobile phones are specifically designed for the minute nature of mobile industry BGAs. These machines often include split-vision assist cameras to allow for detailed work, as well as some automated functions for large-scale rework projects.

Why Manufacturers Are Beginning to Use Rework Machines

BGA rework stations have several applications that make them attractive to manufacturers and repair service providers. Some of the top reasons manufacturers use rework stations include:

• Part corrections: A PCB may contain multiple parts that are attached to the board incorrectly. Whether due to BGA removal, heat-cycling or solder joint voiding, incorrectly attached parts can be fixed using a BGA rework station to redo the part connections.
• Upgrades: Manufacturers often need to swap out parts on a PCB due to an upgrade, so instead of throwing out each PCB, they simply rework the board.
• Component replacements: Components can break due to natural wear and tear from physical stress and usage, but they may also be damaged due to accidents like liquid ingress. Many of these problems can be fixed with a BGA rework station to swap out parts or reset solder joints.
• Assembly fixes: Assembly mistakes happen, but they don't have to be as costly. Whether the BGA orientation is wrong, an error occurred during assembly or testing reveals a critical problem that requires a redesign, BGA rework stations can be used to change the assembly.

While there's no way to repair damaged mobile devices by simply redoing the original assembly process, a well-designed rework station and trained technician can bring the device back to full functionality. This presents a significant cost benefit to manufacturers, who can simply rework a board instead of replacing it entirely. It also helps to reduce electronic waste, which benefits the environment.

Types of BGA Rework Stations for Mobile Phones

Manufacturers typically use two different types of BGA rework stations for mobile phones: hot air or infrared (IR). These specific kinds of rework stations are discussed in more detail below:

• Hot air rework stations: Hot-air rework stations work just like their name implies — they apply hot air to heat BGAs. This more traditional setup comes with nozzles of different diameters to direct hot air to the surface of the circuit board and uses a generalized board heater on the lower portion. Because these setups use an air pump, they tend to be louder than infrared rework stations, but their establishment in the industry also means that more technicians are trained to use hot air BGA rework stations.
• Infrared rework stations: IR rework stations use precise beams of infrared or heat lights to heat BGAs. IR stations come in a range of tiers, using ceramic heaters in the low and mid-tier stations and focus beams in the high-tier stations. Higher-tier IR stations provide excellent isolation of the heat beam without damaging adjacent regions, making these stations excellent for detailed rework jobs. This station is silent but does require more maintenance than hot air stations. It's also a newer technology, so fewer technicians are trained on IR BGA rework stations.

Each of these rework station types offers their own features, but the key is knowing which features will best suit your application. Some of the most significant parameters to consider when choosing a BGA rework station for mobile phones include temperature control and efficiency.

While IR allows for more isolated temperature control, they take significantly longer to bring target sections to the temperature required, especially for new boards using lead-free solder. Hot air rework stations, on the other hand, have a good level of temperature control due to the use of focused air nozzles and can bring targets to temperature much more quickly. If you also factor in training, hot air rework stations are more firmly established in the industry, meaning that technicians are more likely to know how to use hot air effectively, unlike IR which is a newer technology that often requires additional training.

While both IR and hot air BGA rework stations have their advantages and disadvantages that make them better for specific kinds of applications, the operator's skill is the most important factor. At Precision PCB Services, our focus is on hot air BGA rework stations since this technology is better established.

Choose Precision PCB

BGA rework for mobile phones requires both a high-quality rework station and a skilled technician to be successful. To help meet these needs, Precision PCB Services, Inc. supplies industry-leading BGA rework stations, and we offer complete technical training and lifetime support. You can trust Precision PCB Services to help you choose the best rework station for your needs and get your technicians trained on using a BGA rework station for mobile phone repairs.

Since 1991, Precision PCB has been a trusted name in the electronics industry. We pride ourselves on providing the latest information in the design, technological and training requirements of electronics reworking processes, which informs our comprehensive approach to the rework, repair and assembly processes. This approach helps us equip our clients with the most successful and cost-effective rework solution every time.

For more information on our solutions for BGA rework stations for mobile phones, fill out our contact form, and we’ll respond as soon as possible.