HDI is the English abbreviation of High Density Interconnector. The manufacturing of High Density interconnection (HDI) is printed circuit board, and the printed circuit board is the structural element formed by the insulation material with the conductor wiring.On printed circuit boards made in the final product, its installation of integrated circuits, transistors, diodes, passive components (such as: resistor, capacitor, connectors, etc.) and other various kinds of electronic components.By connecting the wires, electronic signals can be connected and functional.Therefore, the printed circuit board is a kind of platform that provides the connection of components, which can be used to undertake the basis of contacting parts.
Because of the printed circuit board is not generally end products, so in the name of the definition, slightly chaotic, for example: personal computer motherboards, circuit board called the motherboard and cannot be directly called, even though the motherboard is the presence of circuit board but is not the same, so the evaluation industry both on but can't say the same.For example, because the integrated circuit parts are loaded onto the circuit board, the news media calls him the IC board, but in essence he is not the same as the printed circuit board.
Under the premise of the complication of electronic products tend to be multi-functional, integrated circuit component of contact distance is getting smaller, the speed of signal is relatively improved, followed by connection between the increase of the number and some locality to shorten the length of the wiring, which would require the application of high density line configuration and microporous technology to achieve their goals.Wiring and jumper are basically for single and double panel has its difficulties, and Circuit Board to multiple stratification, and as a result of the signal line continuously increase, more power supply layer and ground layer as the design must be means, these are prompting from layer Printed Circuit Board (Multilayer Printed Circuit Board) is more common.
For the electrical requirement of high speed signal, the circuit board must provide impedance control, high frequency transmission capacity, and reduce unnecessary radiation (EMI).With the structure of Stripline and Microstrip, multilayering becomes the necessary design.To reduce the quality of the signal transmission problem, will use a low dielectric coefficient, low attenuation of insulation materials, in line with the miniaturization of electronic components packaging and array, and the circuit board are also constantly increased density in response to demand.The emergence of assembly methods such as Ball Grid Array, Chip Scale Package, and Direct Chip Attachment has pushed the printed circuit board to an unprecedented high density level.
Who are under the diameter less than 150 um hole known in the industry of microporous (Microvia), using the geometrical structure of the microporous technology by the circuit can improve the efficiency of assembly, space utilization, etc, for the miniaturization of electronic products at the same time also has its necessity.