Basic knowledge of integrated circuit packaging BGA packaging

What is BGA encapsulation?

The full English name of BGA is Ball Grid Array Package. The feature of this package is that the outer lead becomes a solder ball or solder bump, which is arrayed and distributed on the basic bottom plane.

Features of BGA package:

1) Better electrical performance.

Replacing the lead wire with solder ball shortens the signal transmission path and reduces the resistance. The thickness is more than 1/2 less than that of QFP, and the weight is more than 3/4 less.

2) Increased yield and potential cost reduction

In the previous packaging form, the pins are divided into four parts. When there are many pins and the spacing is shortened to a certain extent, the pins are easy to deform, while the BGA solder ball is at the bottom of the package, which can arrange more O/I numbers.

3) The pin is firm and convenient for transportation.

4) Reduce the problem of common surface.

The surface tension of BGA solder ball during melting has the property of "self-alignment", which reduces the loss caused by O/I common surface.

Common BGA packaging:

English name of PBGA: Plastic-BGA (plastic BGA) is made of organic material substrate. The bare sheet is connected to the top pin of the substrate through bonding and wire bonding (WB) * and then injection molding is used.

CBGA English name: Ceramic-BGA (ceramic BGA) uses multilayer ceramic substrate, and the bare chip is connected to the substrate pin through flip chip technology (FC) * and then sealed with a cover and glass.

TBGA English name: Tape-BGA (carrier BGA) adopts multi-layer carrier substrate, and the bare chip is connected to the substrate pin through lead bonding or flip chip technology, and then sealed with metal cover plate.

FCBGA English name: Flip-Chip BGA (flip chip BGA) substrate is a single layer or ceramic substrate, and the bare chip is connected to the substrate pin through flip technology.

*Wire bonding (WB) and flip chip FC technology are common methods of chip interconnection in the packaging process, that is, connecting the chip bonding area with the I/O lead of the electronic packaging shell or the metal bonding area on the substrate. The common methods of chip interconnection include: wire bonding, flip chip, and carrier automation.

English name of wire bonding: WB for short

This process was adopted in the Bell Laboratory of the United States in 1957. It uses thin metal wire and uses heat, pressure and ultrasonic energy to make the metal lead and the substrate pad tightly welded to realize the electrical interconnection between chips and substrates and the information exchange between chips.

Flip Chip

This process was developed by IBM in the early 1960s. The side with contact point or solder ball is called the front. The common chip packaging is to paste the bare chip with solder pad or ball side up on the circuit board, and then lead the gold wire to the circuit board pad. The flip chip process is to paste the side with solder ball on the circuit board