IC Package Principles and Functional Characteristics

This article will introduce some of the packaging principles and functional characteristics of everyday ICs. By understanding the packaging of various types of ICs, electronic engineers can accurately select ICs when designing electronic circuit principles, and can quickly and accurately burn factory mass production. Find the model of the burner that corresponds to the IC package.

 1. DIP dual in-line package

DIP refers to integrated circuit chips packaged in dual in-line form. Most small and medium-sized integrated circuits (ICs) use this type of package, and the number of pins is generally less than 100. ICs in DIP packages have two rows of pins that need to be plugged into a chip socket with a DIP structure. Of course, it can also be directly inserted on a circuit board having the same number of holes and geometric arrangement for soldering. Chips in DIP packages should be handled with care when plugging or unplugging from the chip socket to avoid damaging the pins.

The DIP package has the following features:

  1. 1. Suitable for perforation welding on PCB (printed circuit board), easy to operate.
  2. 2. The ratio between the chip area and the package area is large, so the volume is also large.
  3. 3. DIP is the most popular plug-in package, including standard logic ICs, memory and microcomputer circuits!

2. QFP / PFP type package

The QFP/PFP package has a small distance between the chip pins and a very thin pin. Generally, large-scale or very large integrated circuits are used in this package. Chips packaged in this form must be soldered to the motherboard using SMD (Surface Mount Device Technology). Chips mounted with SMD do not have to be perforated on the motherboard. Generally, solder joints of corresponding pins are designed on the surface of the motherboard. The soldering to the motherboard can be achieved by aligning the legs of the chip with the corresponding solder joints.

The QFP/PFP package has the following features:

  1. 1. Suitable for SMD surface mount technology to install wiring on the PCB board.
  2. 2. Low cost, suitable for low and medium power consumption, suitable for high frequency use.
  3. 3. Easy to operate and high reliability.
  4. 4. The ratio between the chip area and the package area is small.
  5. 5. Mature sealing type can adopt traditional processing methods;

At present, QFP/PFP package applications are very extensive, and many MCU manufacturers’ A chips use this package.


3. BGA type package

With the development of integrated circuit technology, the packaging requirements for integrated circuits are more stringent. This is because the packaging technology is related to the functionality of the product. When the frequency of the IC exceeds 100 MHz, the traditional packaging method may produce the so-called “CrossTalk” phenomenon, and when the number of IC pins is greater than 208 Pin, the conventional packaging method has Its difficulty. Therefore, in addition to using the QFP package, most of today’s high-footprint chips are converted to BGA (BALL Grid Array PACKAGE) packaging technology.

The BGA package has the following features:

  1. 1. Although the number of I/O pins is increased, the distance between the pins is much larger than that of the QFP package, which improves the yield.
  2. 2. BGA’s array solder balls have a large and short contact surface with the substrate, which is good for heat dissipation.
  3. 3. BGA array solder ball has short pins, which shortens the signal transmission path, reduces lead inductance and resistance, and has small signal transmission delay and greatly improved adaptation frequency, thus improving circuit performance.
  4. 4. Assembly can be used for coplanar welding, and the reliability is greatly improved.
  5. 5. BGA is suitable for MCM packaging and can achieve high density and high performance of MCM.

4.SO type package

SO type packages include: SOP (small outline package), TOSP (small outline package), SSOP (shrink SOP), VSOP (very small outline package), SOIC (small outline integrated circuit package) and other similar to QFP form The package is only in the form of a chip package with pins on both sides. This type of package is one of the surface mount packages, and the leads are drawn in an “L” shape from both sides of the package.

A typical feature of this type of package is that many pins are placed around the packaged chip. The package operation is convenient and the reliability is relatively high. It is one of the current mainstream packaging methods. Currently, it is commonly applied to some memory type ICs.


5. QFN package type

The QFN is a leadless quad flat package that is a lead-free package with a peripheral termination pad and a die pad for mechanical and thermal integrity exposure.

The package can be square or rectangular. The four sides of the package are equipped with electrode contacts. Due to the absence of leads, the placement area is smaller than QFP and the height is lower than QFP.

Features of the QFN package:

  1. Surface mount package, leadless design;
  2. The leadless pad design occupies a smaller PCB area;
  3. The components are very thin (<1mm), which can meet the requirements of space-critical applications;
  4. Very low impedance, self-inductance, for high speed or microwave applications;
  5. has excellent thermal performance, mainly because of the large area of thermal pad on the bottom;
  6. Light weight, suitable for portable applications;

The small form factor of the QFN package can be used in portable consumer electronics such as notebook computers, digital cameras, personal digital assistants (PDAs), mobile phones and MP3s. From the market point of view, QFN packaging is more and more concerned by users. Considering the cost and volume factors, QFN packaging will be a growth point in the next few years, and the development prospects are extremely optimistic.

6. PLCC package type

PLCC is a plastic chip package carrier with lead. Surface mount type package, the leads are drawn from the four sides of the package, and have a “D” shape, which is much smaller than the DIP package. The PLCC package is suitable for mounting wiring on the PCB with SMT surface mount technology, and has the advantages of small size and high reliability.

PLCC is a special pin chip package, which is a kind of chip package. The pins of this package are bent inward at the bottom of the chip, so the chip pins are not visible in the top view of the chip. This chip is soldered using a reflow process and requires special soldering equipment. It is also cumbersome to remove the chip during debugging, and it is rarely used now.



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