DIP package: In the 1970s, the chip package was basically DIP(Dual ln-line Package), which was suitable for PCB (printed circuit board) perforation installation and convenient for wiring and operation. DIP package has many structural forms, including multi-layer ceramic DIP, single-layer ceramic DIP, lead frame DIP and so on. However, the packaging efficiency of DIP packaging is very low, and the ratio of chip area to packaging area is 1: 1.86, so the area of packaged products is large. In an ideal state, the ratio of chip area to package area is the best, but it can't be achieved unless it is packaged, but with the development of packaging technology, this ratio is getting closer and closer.
TSOP packaging: In 1980s, chip packaging technology TSOP appeared and was widely recognized by the industry. TSOP is the abbreviation of "thin and small outline bag", which means thin and small bag. SMT technology (surface mounting technology) is used to attach directly to the surface of PCB. When the TSOP package is in the overall size, the parasitic parameters (which will cause output voltage disturbance when the current changes greatly) are reduced, which is suitable for high-frequency applications, convenient to operate and high in reliability. At the same time, TSOP packaging has the advantages of high output and low price, so it has been widely used.
BGA packaging: In the 1990s, with the development of technology, the integration of chips has been continuously improved, the number of I/O pins has increased dramatically, and the power consumption has also increased, so the requirements for integrated circuit packaging have become more stringent. In order to meet the needs of development, BGA packaging has been applied to production. BGA is the abbreviation of English Ball Grid Array Package, namely ball grid array package.
I/O terminals of BGA package are distributed under the package in the form of circular or columnar solder joints in the array. The advantage of BGA technology is that although the number of I/O pins has increased, the pin spacing has not decreased, thus improving the assembly yield. Although the power consumption is increased, BGA can be welded by controlled chipping method to improve its electrothermal performance. The thickness and weight are lower than those of the previous packaging technology; The parasitic parameters are reduced, the signal transmission delay is small, and the use frequency is greatly improved; * * * It can be assembled by surface welding with high reliability.
CSP package: CSP (Chip Scale Package) refers to chip scale package. CSP packaging is the latest generation of chip packaging technology, and its technical performance has been improved. CSP packaging can make the ratio of chip area to package area exceed 1: 1. 14, which is quite close to the ideal situation of 1: 1. The absolute size is only 32 square millimeters, which is about 1/3 of that of ordinary BGA, and only the area of TSOP memory chip. Compared with BGA package, CSP package can increase the storage capacity by 3 times in the same space.
The center pin form of CSP package effectively shortens the signal transmission distance, reduces its attenuation, and greatly improves the anti-interference and anti-noise performance of the chip. In CSP package mode, the chip is soldered on the PCB by solder balls. Because the contact area between solder joint and PCB is large, the heat generated when the chip works is easily conducted to PCB and radiated. CSP package can dissipate heat from the back with good thermal efficiency. The thermal resistance of CSP is 35℃/W, while that of TSOP is 40℃/w. ..