The DSP chip packaged by GBA is best used more than four layers. Here's why.
First, the density of IC and PCB welding of the general GBA package is relatively high, that is, the line density is very high, the space left for the line between the pad and the pad is very small, and it can only be connected to the inner layer or the bottom line through the through hole. To avoid the BGA welding area too many lines easy to lean into short circuit.
Second, the high density of the signal line is easy to cause mutual electromagnetic interference, some impedance lines have higher wiring requirements, in order to prevent mutual electromagnetic interference and meet the wiring requirements of the impedance line, it is necessary to have part of the line to the inner layer, some of the floor, and each layer of the line to cloth a layer of ground layer to shield the electromagnetic signal interference between the layers of the signal line.
So. Generally, boards with BGA chips use more than four layers of PCB.
The optimal number of layers depends on the intensity of your signal line. If four layers aren't enough, use six, and so on.
The DSP chip packaged by GBA is best used more than four layers. Here's why.
First, the density of IC and PCB welding of the general GBA package is relatively high, that is, the line density is very high, the space left for the line between the pad and the pad is very small, and it can only be connected to the inner layer or the bottom line through the through hole. To avoid the BGA welding area too many lines easy to lean into short circuit.
Second, the high density of the signal line is easy to cause mutual electromagnetic interference, some impedance lines have higher wiring requirements, in order to prevent mutual electromagnetic interference and meet the wiring requirements of the impedance line, it is necessary to have part of the line to the inner layer, some of the floor, and each layer of the line to cloth a layer of ground layer to shield the electromagnetic signal interference between the layers of the signal line. So. Generally, boards with BGA chips use more than four layers of PCB. The optimal number of layers depends on the intensity of your signal line. If four layers aren't enough, use six, and so on.