PCB News - CPU packaging technology introduction

I often hear two words mentioned by various processor manufacturers in public: architecture and packaging technology. Then, what are these two things and what impact have they had on the CPU?
The impact of the CPU architecture on the processor quality does not need to be discussed here. Intel’s Core micro-architecture and AMD’s direct connection architecture are all based on strength. If you are more concerned about stability and energy consumption than these I can't grasp the focus, and I won't achieve such a huge market performance today.

What is the other thing called "Packaging Technology"? How does it affect the processor? Let's take a look together.

One, the definition of CPU package

The so-called CPU, when you look at the shell, is actually an integrated circuit board with high-tech content. Then in the industry, there is a definition of its packaging technology according to the essence of the CPU:

Packaging technology is a technology in which integrated circuits are packaged with insulating plastic or ceramic materials, while CPU is a product in which the CPU core circuit (also called CPU core or chip core) is packaged with a shell.

Second, the meaning of CPU packaging

CPU packaging is a must for the chip, and it is also very important. Because the chip must be isolated from the outside world to prevent impurities in the air from corroding the chip circuit and causing electrical performance degradation. On the other hand, the packaged chip is also easier to install and transport. Since the quality of packaging technology also directly affects the performance of the chip itself and the design and manufacturing of the PCB (printed circuit board) connected to it, it is very important. Packaging can also be said to refer to the housing used to install semiconductor integrated circuit chips. It not only plays the role of placing, fixing, sealing, protecting the chip and enhancing thermal conductivity, but also a bridge between the internal world of the chip and the external circuit-on the chip. The contacts are connected to the pins of the package shell with wires, and these pins are connected to other devices through wires on the printed circuit board. Therefore, for many integrated circuit products, packaging technology is a very critical part.

3. Classification and characteristics of packaging technology

1, BGA package

BGA technology (Ball Grid Array Package) is ball grid array packaging technology. The emergence of this technology has become the best choice for high-density, high-performance, multi-pin packages such as CPU, motherboard south and north bridge chips. However, the BGA package occupies a relatively large area of the substrate. Although the number of I/O pins of this technology increases, the distance between the pins is much larger than that of QFP, which improves the assembly yield. And this technology uses the controllable collapse chip method to weld, which can improve its electrothermal performance. In addition, the assembly of this technology can be coplanar welding, which can greatly improve the reliability of the package; and the packaged CPU realized by this technology has a small signal transmission delay, and the adaptation frequency can be greatly improved.

The characteristics of the BGA package are: Although the number of I/O pins increases, the distance between the pins is much larger than the QFP package method, which improves the yield; power consumption increases, but the controllable collapse chip method is used for welding, which can improve electric heating Performance; the signal transmission delay is small, and the adaption frequency is greatly improved; the assembly can be coplanar welding, and the reliability is greatly improved.

2, LGA package

The full name of LGA is Land Grid Array, which literally translates to grid array packaging. This technology uses contacts instead of pins. It corresponds to the previous packaging technology of Intel processors, Socket 478, which is also called Socket T. For example, the product line LGA775 means that this product line has 775 contacts.

The characteristics of the LGA package are: the metal contact type package replaces the previous pin-shaped pins, which greatly reduces the delay of CPU processing and transmission; it is necessary to install a CPU buckle on the motherboard to fix it, so that the CPU can be pressed correctly On the elastic tentacles exposed by the Socket; the principle is similar to that of the BGA package, but the BGA is soldered to death, while the LGA can be unlocked at any time to replace the chip, and the maintenance process is relatively convenient.

3. OPGA package

OPGA package is also called Organic pin grid Array. The substrate of this package uses glass fiber, similar to the material on a printed circuit board.

The features of OPGA package are: reduce impedance and package cost, shorten the distance between external capacitor and chip core, which can better improve core power supply and filter current clutter.

4. DIP package

DIP package is also called dual in-line package technology (Dual In-line Package), which refers to integrated circuit chips packaged in dual in-line form. Most small and medium-sized integrated circuits use this form of packaging. The number of pins is Generally not more than 100. The DIP packaged CPU chip has two rows of pins, which need to be inserted into the chip socket with the DIP structure. Of course, it can also be directly inserted into a circuit board with the same number of solder holes and geometric arrangement for soldering. The DIP packaged chip should be especially careful when plugging or unplugging from the chip socket to avoid damage to the pins. DIP package structure forms are: multilayer ceramic double in-line DIP, single-layer ceramic double in-line DIP, lead frame DIP (including glass ceramic sealing type, plastic encapsulation structure type, ceramic low-melting glass encapsulation type) Wait.

DIP package is characterized by: suitable for perforation soldering on the PCB (printed circuit board), easy to operate, and the ratio between the chip area and the package area is large, so the volume is also large.

5, QFP package

QFP packaging is also called Plastic Quad Flat Pockage (Plastic Quad Flat Pockage). The distance between the pins of the CPU chip realized by this technology is very small, and the pins are very thin. Generally, large-scale or very large-scale integrated circuits use this packaging form. The number of pins is generally above 100.

The characteristics of the QFP package are: convenient operation and high reliability when encapsulating the CPU; the package size is small, the parasitic parameters are reduced, and it is suitable for high-frequency applications; this technology is mainly suitable for installing and wiring on the PCB with SMT surface mount technology.

6, PFP package

PFP package is also called Plastic Flat Package (Plastic Flat Package). Chips packaged with this technology must also be soldered to the motherboard using SMD technology. Chips mounted by SMD do not need to be punched on the motherboard. Generally, there are designed corresponding pin pads on the surface of the motherboard. Align the pins of the chip with the corresponding pads to achieve welding with the motherboard.

The characteristic of PFP package is that it is difficult to disassemble the soldered chip without special tools; it is basically similar to QFP technology, but the package shape is different in appearance.

In the eyes of many friends in the industry, ceramic packages may be seen more in AMD processor products

7, PGA package

PGA package is also called ceramic pin grid array packaging technology (Ceramic Pin Grid Arrau Package). The chip packaged by this technology has multiple square-array pins inside and outside, and each square-array pin is spaced a certain distance along the periphery of the chip. The distance arrangement can form 2 to 5 circles according to the number of pins. When installing, insert the chip into a special PGA socket. In order to make the installation and removal of the CPU more convenient, starting with the 486 chip, a ZIF CPU socket has appeared, which is specifically used to meet the installation and removal requirements of the PGA packaged CPU.

The characteristic of the PGA package is that it is suitable for occasions such as tests or demonstrations with frequent plug-in operations.

8, MPGA package

MPGA package is also called micro PGA, that is, micro pin grid array package. At present, AMD’s Opteron and Intel’s Xeon (Xeon) are used in server CPUs. It is a relatively advanced technology and is used in many high-end CPUs. In the product.

The characteristic of MPGA package is: on the basis of the advantages of PGA package, the PGA is miniaturized by more advanced technology to better control the space.

9, CPGA package

CPGA package is also called ceramic package (Ceramic PGA), a PGA package mode that uses ceramic materials.

The characteristic of CPGA is: the product uses ceramic material to achieve better insulation effect, and heat dissipation and heat resistance are also properly controlled. It can be seen in many CPUs produced by AMD.

Two dual-core processors can be placed in the same volume shell, which requires a smaller M-level nano process

10, PPGA package

PPGA package is also called Plastic Pin Grid Array.

PPGA package is characterized by the use of a nickel-plated copper heat sink on the top of the processor to improve heat conduction; the pins are arranged in a zigzag pattern, and improper operation may easily cause the pins to break.

11, OOI package

OOI package is also called substrate grid array (OLGA). The chip uses an inverted chip design, where the processor is attached to the substrate facing down, and there is an integrated heat spreader (IHS) that helps the radiator transfer heat to the properly installed fan radiator.

The characteristics of OOI package are: better signal integrity, more effective heat dissipation and lower self-induction effect.

12. FC-PGA package

FC-PGA package is also called inverted chip pin grid array package. In the FC-PGA package, the pins at the bottom are arranged in a zigzag pattern, and the chip is reversed, so that the die or the processor part that constitutes the computer chip is exposed on the upper part of the processor, and the capacitor area (processor center) at the bottom is installed Discrete capacitance and resistance.

The characteristics of the FC-PGA package are: the die is exposed, and the heat dissipation can be achieved directly through the die, which can improve the efficiency of chip cooling; isolate the power signal and ground signal, improve the package performance; the pin arrangement design fixes the processor inserted Orientation, if you insert it casually without paying attention, it is easy to cause the CPU pins to break.

13, FC-PGA2 package

FC-PGA2 can also be regarded as the second generation of FC-PGA, which adds an integrated heat sink (IHS) on the basis of FC-PGA, which has been directly installed on the CPU during factory production.

The characteristics of the FC-PGA2 package are: on the basis of FC-PGA, the IHS is in direct contact with the die, and the increase in surface area and the effect of direct conduction greatly improve the heat dissipation performance.

The above is the introduction of CPU packaging technology. Ipcb is also provided to PCB manufacturers and PCB manufacturing technology.