HDI PCB(High Density Interconnector PCB), that is, HDI PCB, is a line distribution density using micro-blind buried via technology. It includes inner layer lines and outer layer lines, and then uses drilling and hole metallization to realize the internal connection function of each layer line. With the development of electronic products in the direction of high density and high precision, the same requirements are put forward for circuit boards. The most effective way to increase PCB density is to reduce the number of through holes, and accurately set blind and buried holes to meet this requirement, resulting in HDI PCB. The AET-PCB part will be divided into parts about the engineering design, material selection, processing technology and processing technology of the PCB factory.
1. Concept
HDI PCB: High-density interconnection technology, high-density interconnection technology. It is a multi-layer board made by adding layer method and micro blind buried via method.
Micro-holes: In PCBs, holes with a diameter of less than 6 meters (150um) are called micro-holes.
Buried hole: BuriedVia cavity buried in the inner layer of the hole, invisible in the finished product, is mainly used for the conduction of the inner line, which can reduce the probability of signal interference and maintain the continuity of the characteristic impedance of the transmission line. Since buried vias do not consider the surface area of the PCB, more components can be placed on the surface of the PCB.
Blind hole: Blind, connect the surface layer and the inner layer without penetrating the entire board through the through hole.
2. Process flow
At present, high-density interconnection technology(HDI PCB) can be divided into a first-order process:
1+N+1 HDI PCB, 2+N+2 HDI PCB, 3+N+3 HDI PCB, 4+N+4 HDI PCB, 5+N+5 HDI PCB, 6+N+6 HDI PCB, anylayers HDI PCB.