BGA vs. LGA: The Difference between the Two Grid Arrays

Remember when we had to deal with huge ICs? Thankfully, that era is over, and we now have access to smaller compact ICs. Undoubtedly, manufacturers use these tiny ICs to build small but impressive CPUs that can control some of the most powerful computers. But, when talking about CPUs, there’s a high chance you’ll come across terms like BGA and LGA. Though they sound alike, they describe different types of IC packages and breed variations.

Read on to learn more about these IC packages, when to use them, and their differences.

 

What is a BGA?

The Ball Grid Array (BGA) is an IC package that precedes the Pin Grid Array (PGA). While the PGA uses pins to connect to a PCB, the BGA uses pads with tiny solder balls.

BGAs can only work with PCBs that feature copper pad patterns matching the solder balls. Also, you can place the solder balls manually or automatically. And tacky flux helps BGAs to stay in place during assembly.

After the assembly, manufacturers heat the BGAs with an infrared heater or in a reflow oven. This process melts the solder and secures the package to the PCB. Also, the BGA will have correct alignment with proper separation distance–from other components.

Once the solder cools and solidifies, it will connect the BGA to the PCB. Sometimes, you’ll find these solder balls on the package and PCB. It’s a way to connect two packages.

What is an LGA?

The Land Grid Array (LGA) is an IC package with pins on the socket instead of the IC. However, this only applies when a PCB has a socket connector.

If your PCB doesn’t have a socket, it’s possible to solder LGAs to the board directly.

LGAs have rectangular contact grids (called “land”) on their undersides. Also, you don’t have to use all the grid rows and columns.

Additionally, manufacturers can make these lands with solder paste or LGA sockets. Also, the grid elements can have different polygonal shapes and sizes, like triangular or circular. Some may even have a honeycomb appearance.

Manufacturers usually optimize their designs for factors like getting the best shape for matching spring contacts, contact likeness, and proper electrical distance to nearby contacts.

What is a CPU Socket?

CPU sockets on PCBs utilize different pins that help connect a CPU to a computer motherboard. In addition, CPUs connected via sockets don’t need solder, allowing easy replacements.

Additionally, manufacturers often use CPU sockets for desktop gaming PCs, while laptops mostly have soldered versions.

Choosing a motherboard goes beyond getting the features you want. So, you must also examine if the motherboard has a CPU socket that supports your CPU model.

So, it doesn’t matter if you have a state-of-the-art CPU. However, it won’t work if you have the wrong socket. Manufacturers like Intel and AMD have different CPU socket types for their mainstream and high-end desktop CPUs.

LGA vs. BGA

Now let’s take a closer look at how these grid arrays are different and what you can use them for in a PC circuit.

LGA vs BGA: Pros and Cons

Pros of BGA

• BGAs don’t take up a lot of space because of their small sizes. In other words, they allow for optimal space utilization. But irrespective of the size of these IC packages, it’s possible to create small and powerful gadgets.

• It’s easy to unsolder BGA packages. And the process doesn’t damage the PCB or IC package.

• You can remove old and worn-out solder balls from your BGA package through deballing. 

• Also, you can add new solder balls to your package through the reballing process.

• It’s rare for BGA packages to overheat because they have excellent heat dissipation capabilities.

• BGA chips are not permanent. Therefore, they are easy to unsolder. And you can move them to other devices without any damage. Also, you can use the deballing and reballing process if the solder balls are weak.

• You can use the BGA as a computer CPU because of its excellent thermal and mechanical properties.

• BGAs boast of short lead connection paths. As a result, they have low impedance features and can generate signals quickly.

Drawbacks of BGAs

• It’s not easy to inspect solder joints on a BGA package. And you’d need x-rays to access the component-to-PCB connection since BGAs use their bellies to make connections.

• You can’t use BGA packages for many applications because they can only operate on multi-layered circuit boards.

• Although it’s easy to unsolder, you’d need special equipment to solder these packages to the PCB.

• It’s a bit tricky to carry out BGA repairs. And you’ll need expertise and special equipment to execute repairs.

Pros of LGAs

• LGAs are space-efficient due to their small sizes. And you can use them to build small, powerful devices.

• LGA packages are more durable and won’t get damaged easily. Why? Because the pins are on the board, not the CPU. Also, the socket’s bear points have impressive durability.

• LGA pins are tiny, allowing manufacturers to fit many pins in a small area.

Cons of LGAs

• Although LGAs don’t get damaged easily, they can be expensive to fix if problems occur.

LGA VS BGA: Components

LGAs don’t use balls for connections. Instead, they use flat contacts that need sockets or direct soldering to connect to a PCB.

In contrast, BGAs use balls for connecting to PCBs. And manufacturers usually attach these balls to the bellies of these packages.

LGAs vs. BGAs: Ease of Connection and Replacement

LGAs are pretty easy to connect to a PCB. Usually, these PCBs come with sockets where you can insert your LGA CPUs. Also, there’s no unique replacement process–you only need to remove the old CPU and insert the new one.

On the other hand, BGAs need special equipment to connect and remove them from their CPU sockets. Though it’s almost risk-free, the process is still more expensive than LGA packages.

LGA vs. BGA: Use in Microprocessors

Most top manufacturers like AMD and Intel prefer using LGA packages over BGA, especially for desktop gaming PCs.

Moreover, some manufacturers still use BGA to permanently mount microprocessors, WiFi chips, and FPGAs.

BGA vs. LGA: Which is Better?

BGAs and LGAs are great. But your choice should depend on preferences or what is best suited for your project requirements.