Difference between HDI Board and Ordinary PCB

Introduction to Ordinary PCB

　　The full name of PCB is "Printed Circuit Board",It is an important electronic component, the support for electronic components, and the carrier for the electrical connection of electronic components. Since it is made by using electronic printing technology, it is called a "printed" circuit board.

　　Its main functions are as follows: After electronic equipment adopts printed circuit boards, due to the consistency of the same type of printed circuit boards, the errors in manual wiring can be avoided. Moreover, it enables the automatic insertion or placement of electronic components, automatic soldering, and automatic detection, which ensures the quality of electronic equipment, improves labor productivity, reduces costs, and facilitates maintenance.

Introduction to HDI Board 

　　HDI (High Density Interconnect) board, which is a kind of printed circuit board with a relatively high distribution density of circuits, uses the micro blind and buried via technology. HDI boards have inner layer circuits and outer layer circuits. Then, by utilizing processes such as drilling and metallization inside the holes, the internal connection among the circuits of each layer is achieved.

　　Generally,HDI boards are manufactured by the build-up method. The more times of build-up, the higher the technical grade of the board. Ordinary HDI boards basically have one build-up layer, while high-order HDI boards adopt the build-up technology for two or more times. Meanwhile, they also utilize advanced PCB technologies such as stacked vias, electroplating hole filling, and direct laser drilling.

　　When the density of a PCB increases and exceeds that of an eight-layer board,if it is manufactured with HDI, its cost will be lower than that of the traditional and complicated lamination process. HDI boards are conducive to the application of advanced packaging technologies, and their electrical performance and signal accuracy are higher than those of traditional PCB. In addition, HDI boards have better improvements in terms of radio frequency interference, electromagnetic wave interference, electrostatic discharge, and heat conduction.

Differences between HDI Boards and Ordinary PCB
　　Ordinary PCB substrates are mainly made of FR-4, which is formed by laminating epoxy resin and electronic-grade glass cloth.

　　Generally, for traditional HDI boards, adhesive-backed copper foil is used on the outermost layer. Since glass cloth cannot be penetrated by laser drilling, adhesive-backed copper foil without glass fiber is usually adopted. However, nowadays, high-power laser drilling machines are already capable of drilling through 1180 glass cloth. In this way, there is no difference from ordinary materials.

Development Tendency　　
　　Electronic products are developing towards high density and high precision. The term "high" here includes improving performance and reducing the size. High-density integration technology helps to miniaturize terminal products and meet higher electronic standards. Currently, many popular electronic products use HDI boards. With the upgrading of electronic products and the market demands, HDI boards will witness rapid development.