Packaging refers to the circuit pin on the silicon chip, with a wire connection to the external junction, in order to connect with other devices. Package form refers to the housing used to install semiconductor integrated circuit chips. It not only plays the role of installing, fixing, sealing, protecting the chip and enhancing the electric heating performance, but also connects to the pins of the package shell with wires through the contacts on the chip, and these pins are connected with other devices through the wires on the printed circuit board, so as to realize the connection between the internal chip and the external circuit. 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 to decline. On the other hand, the packaged chip is also easier to install and transport. Because the quality of the packaging technology also directly affects the performance of the chip itself and the design and manufacture of the PCB(printed circuit board) connected with it, it is crucial. An important indicator to measure whether a chip package technology is advanced or not is the ratio of chip area to package area, and the closer the ratio is to 1, the better.

The main factors to consider when packaging:

    1, the chip area and package area ratio to improve packaging efficiency, as close as possible to 1:1;
    2, the pin should be as short as possible to reduce the delay, and the distance between the pins should be as far as possible to ensure mutual interference and improve performance;
    3, based on the requirements of heat dissipation, the thinner the package, the better. Package is mainly divided into DIP dual in-line and SMD patch package two kinds. In terms of structure, the package has experienced the development of the earliest transistor TO (such as TO-89, TO92) package TO dual-in-line package, and then the SOP small exterior package developed by PHILIP Company. Then gradually derived SOJ (J-pin small shape package), TSOP (thin small shape package), VSOP (very small shape package), SSOP (reduced SOP), TSSOP (thin reduced SOP) and SOT (small shape transistor), SOIC (small shape integrated circuit) and so on.
    From the aspect of material media, including metal, ceramic, plastic, plastic, at present, many high-strength working conditions demand circuits such as military and aerospace levels still have a large number of metal packages.
Packaging has roughly gone through the following development process:

    Structure: TO->DIP->PLCC->QFP->BGA ->CSP; Materials: Metal, ceramic -> Ceramic, plastic -> Plastic; Pin shape: Long lead straight insert -> Short lead or no lead mount -> ball convex point; Assembly mode: Through hole insertion -> Surface assembly -> Direct installation of the specific package form

1. SOP/SOIC package
    SOP is the abbreviation of English Small Outline Package, that is, small outline package. SOP packaging technology was developed by Phillip Company in 1968 ~ 1969. Later, it gradually derived SOJ (J-pin small shape package), TSOP (thin small shape package), VSOP (very small shape package), SSOP (reduced type SOP), TSSOP (thin reduced type SOP), SOT (small shape transistor), SOIC (small shape integrated circuit) and so on.
2, DIP package
    DIP is the abbreviation of the English Double in-line package. One of the plug-in type packages, the pins lead from both sides of the package, and the packaging material is plastic and ceramic. DIP is the most popular plug-in package, the application range includes standard logic ics, memory LSI, microcomputer circuits and so on.
3, PLCC package
    PLCC is the abbreviation of the English Plastic Leaded Chip Carrier, that is, the plastic sealed J-lead chip package. PLCC package, square shape, 32-pin package, there are pins on all sides, the shape size is much smaller than DIP package. PLCC package is suitable for SMT surface mount technology to install wiring on PCB, with the advantages of small size and high reliability.
4, TQFP encapsulation
    TQFP is the abbreviation of the English thin quad flat package, that is, the thin plastic seal four corner flat package. The four-sided Flat package (TQFP) process makes efficient use of space, thereby reducing the space requirements for printed circuit boards. Due to the reduced height and volume, this packaging process is ideal for space-demanding applications such as PCMCIA cards and networking devices. Almost all of ALTERA's CPLDS/FPGas come in TQFP packages.
5, PQFP encapsulation
    PQFP is the abbreviation of the English Plastic Quad Flat Package, that is, the plastic sealing square flat package. PQFP package chip pin distance is very small, the pin is very thin, generally large-scale or very large scale integrated circuit using this form of packaging, the number of pins is generally more than 100.
6, TSOP packaging
    TSOP is the abbreviation of English Thin Small Outline Package, that is, thin small size package. A typical feature of TSOP memory packaging technology is to make pins around the package chip, and TSOP is suitable for using SMT technology (surface mount technology) to install wiring on the PCB (printed circuit board). TSOP package size, the parasitic parameter (current changes greatly, resulting in output voltage disturbance) is reduced, suitable for high-frequency applications, easy to operate, and relatively high reliability
7, BGA package
    BGA is the abbreviation of the English Ball Grid Array Package, that is, the ball grid array package.
    With the progress of technology in the 1990s, chip integration continued to improve, the number of I/O pins increased sharply, power consumption also increased, and the requirements for integrated circuit packaging were more stringent. In order to meet the needs of development, BGA packaging began to be used in production.

    The memory encapsulated by BGA technology can increase the memory capacity by two to three times without changing the volume of the memory. Compared with TSOP, BGA has a smaller volume, better heat dissipation performance and electrical performance. BGA packaging technology has greatly improved the storage capacity per square inch, using BGA packaging technology memory products under the same capacity, the volume is only one-third of TSOP packaging; In addition, compared with the traditional TSOP package, the BGA package has a more rapid and effective heat dissipation way.

    The I/O terminals of BGA package are distributed under the package in the form of circular or cylindrical solder joints in the form of array. The advantage of BGA technology is that although the number of I/O pins increases, the spacing of pins increases rather than decreases, thus improving the assembly yield. Although its power consumption increases, BGA can be welded by controlled collapse chip method, which can improve its electric heating performance. The thickness and weight are reduced compared with previous packaging technologies; The parasitic parameter is reduced, the signal transmission delay is small, and the use frequency is greatly increased. Assembly can be coplanar welding, high reliability.

    When it comes to BGA packaging, it is necessary to mention Kingmax's patented TinyBGA technology, TinyBGA English full name Tiny Ball GridArray (small ball grid array package), which is a branch of BGA packaging technology. Kingmax was successfully developed in August 1998, the ratio of the chip area to the package area is not less than 1:1.14, which can increase the memory capacity by 2 to 3 times under the same internal volume, compared with TSOP package products, it has a smaller volume, better heat dissipation performance and electrical performance.

    Memory products using TinyBGA packaging technology have only 1/3 of the volume of TSOP packaging under the same capacity. The pins of TSOP encapsulated memory are led from around the chip, while TinyBGA is led from the center of the chip. This method effectively reduces the transmission distance of the signal, and the length of the signal transmission line is only 1/4 of the traditional TSOP technology, so the attenuation of the signal is also reduced. This not only greatly improves the anti-interference and anti-noise performance of the chip, but also improves the electrical performance.

    Using TinyBGA package chip can resist up to 300MHz external frequency, while using traditional TSOP package technology can only resist up to 150MHz external frequency.

    The TinyBGA package also has a thinner memory thickness (less than 0.8mm package height), and the effective heat dissipation path from the metal substrate to the heat sink is only 0.36mm. Therefore, TinyBGA memory has a higher heat transfer efficiency, which is very suitable for long running systems and excellent stability.