In the current information age, with the rapid development of the electronics industry, products such as computers and mobile phones have become increasingly popular. People have more and more functional requirements and stronger performance requirements for electronic products, but the volume requirements are getting smaller and the weight requirements are getting lighter and lighter. This promotes the development of electronic products in the direction of multi-function, high performance, miniaturization and light weight. In order to achieve this goal, the feature size of IC chips will become smaller and smaller, and the complexity will continue to increase. As a result, the number of I/Os in the circuit will increase, and the I/O density of the package will continue to increase. In order to meet the requirements of this development, some advanced high-density packaging technologies have emerged, and BGA packaging technology is one of them.
BGA packaging appeared in the early 1990s and has now developed into a mature high-density packaging technology. Among all packaging types of semiconductor ICs, BGA packaging has the fastest growth rate during the five-year period from 1996 to 2001. In 1999, the output of BGA was about 1 billion. However, so far, this technology is limited to the packaging of high-density, high-performance devices, and the technology is still developing in the direction of fine pitch and high I/O terminal count. BGA packaging technology is mainly suitable for the packaging of PC chipsets, microprocessors/controllers, ASICs, gate arrays, memories, DSPs, PDAs, PLDs and other devices.
According to the different packaging materials, BGA components mainly have the following types:
PBGA (plastic BGA, BGA in the plastic package); CBGA (ceramic BGA, BGA in the ceramic package); CCBGA (ceramic column BGA, BGA in the ceramic column package); TBGA (tape BGA, BGA in the carrier tape package); CSP( chip scale package or μBGA)
PBGA (Plastic Ball Grid Array), which uses BT resin/glass laminate as the substrate, and plastic (epoxy molding compound) as the sealing material. The solder balls can be divided into lead solder (63Sn37Pb, 62Sn36Pb2Ag) and lead-free solder ( Sn96.5Ag3Cu0.5), the connection between the solder ball and the package body does not require additional solder.
Some PBGA packages have a cavity structure, which is divided into two types: cavity up and cavity down. This kind of PBGA with a cavity is to enhance its heat dissipation performance, it is called thermally enhanced BGA, EBGA for short, and some are also called CPBGA (cavity plastic solder ball array).
Sensitive to moisture, it is not suitable for the packaging of devices that require airtightness and high reliability.
CBGA (Ceramic Ball Grid Array) has the longest history in the BGA package series. Its substrate is multi-layer ceramic, and the metal cover is welded on the substrate with sealing solder to protect the chip, leads and pads. The solder ball material is high temperature eutectic solder 10Sn90Pb, and the connection between the solder ball and the package body needs to use low temperature eutectic solder 63Sn37Pb.
The advantages of the CBGA package are as follows:
The disadvantages of the CBGA package are as follows:
TBGA (Tape Ball Grid Array) is a cavity structure. There are two ways to interconnect the chip and substrate of the TBGA package: flip-chip bonding and wire bonding. The chip is flip-chip bonded on the flexible carrier tape for multi-layer wiring; the peripheral array of solder balls used as the circuit I/O end is installed under the flexible carrier tape; its thick sealing cover is also a heat sink (heat sink), and at the same time In order to strengthen the package body, the solder balls under the flexible substrate have better coplanarity. The chip is bonded to the copper heat sink in the core cavity; the chip pad and the multilayer wiring flexible tape carrier substrate pad are interconnected with bonding wires; the circuit chip, the lead, and the flexible tape carrier pad are encapsulated with a sealant (Potting or coating) up.
The advantages of TBGA are as follows:
The disadvantages of TBGA are as follows: