Encapsulated in CPUs, GPUs, RAM and Flash: Types and Uses

The different chips on the market come with a cover, most of it made of plastic, that covers them. What is this coverage and what is it for? In this article we will talk about the different types of encapsulation that you can find both in PC hardware and in smartphones and found in all types of chips.

It is not possible to manipulate a chip as is, they are too fragile and sensitive, hence the need to place these in what we call an encapsulation, to prevent them from deteriorating quickly and that their manipulation on our part ends up breaking them.

Encapsulated in CPUs

What is the encapsulation of a chip?

You find yourself installing a CPU on the motherboard of your PC, but what you are holding between your fingers is not the processor itself, but the package of it. A layer of plastic or ceramic that is responsible for protecting it. Each and every one of the processors on the market is packaged and used in various types and sizes.

The first differential point is the size, in ordinary PCs most of the packages are made of plastic, but there are applications in which it is necessary to use a ceramic package and even special alloys. For example, the probes and vehicles sent by space agencies make use of encapsulations that protect against special radiation. We also have the case of computer processors on board cars, which must be able to withstand the high temperatures near the engine.

Maquina empaquetado chips

The encapsulation is part of the manufacturing process of a processor, that is why depending on the target application of the CPU we will see how one type of encapsulation or another is used, affecting its final cost. Its utility is very simple, the chips are highly sensitive elements to the inclemency of the environment and that is why it is necessary to protect them since they have been manufactured.

Next we leave you the types of encapsulation most used when manufacturing the different chips that are on the market, there are not all that are available, since this type has a huge amount of variations depending on the number of pins, material used, etc. That is why we have reduced them to the most basic.

Ball Grid Array (BGA)

The Ball Grid Array is the type of encapsulation most used in hardware today, since it is used in the RAM memory chips that we see in the different types of DIMM modules, in the VRAM that is mounted on the graphic cards, as well such as the GPU mounted on the graphics card. This type of encapsulation is used for parts that do not require individual user replacement because they will be fully welded throughout their useful life to a plate directly.

In the case of a BGA, the pins of the package are placed in a matrix at the bottom, these pins connect with the processor that is inside the package, hence the name of Grid Array. For mounting the pins are directly soldered on the PC, forming balls during the process.

PoP Encapsulation (Package on Package)

Encapsulado PoP

PoP type package is a type of package in which two BGA packages are placed vertically on top of each other and have some kind of interconnection between them. It is not to be confused with the 3DIC where two chips are stacked on top of each other, this is clarified to avoid confusion.

SiP Encapsulation (System in Package)

Encapsulado SiP

The SiP type package is used when we have several components mounted on the same PCB together, that is, when we talk about MCM configurations in which there are several processors and / or memories on separate chips. It is the type of packaging most used in smartphones where the LPDDR memory in certain designs is placed inside the processor.

We also have examples of the use of SiP packaging in the world of PC hardware where it is used in AMD Ryzen composed of chiplets or GPUs that make use of HBM2 memory.

Pin Grid Array (PGA)

The Pin Grid Array is the common one among CPUs, since instead of soldering the processor to the board or PCB, it is connected to a socket where the different pins fit into the holes in the socket that serves to make connection with them. The good thing about the PGAs is that it is possible to completely extract them from the board to which they are connected, allowing their subsequent update, hence we can update the CPUs of one PC for another while maintaining the same type of socket.

Each socket therefore corresponds to a type of PGA packaging, when they tell us for example that an Intel CPU makes use of an LGA1200 socket, in reality they are telling us the type of PGA package in which Intel or AMD have manufactured a generation specific CPUs.

As a curiosity, the PGA is also used in the prototyping of certain designs, where a PGA version is manufactured for a specific socket, so those who are testing the new chips do not need to solder them to perform the functional tests.