2+N+2 8L HDI PCB for Hand Held Device

HDI, fully defined as High Density Interconnection, refers to advanced high-density interconnected printed circuit boards. Structurally, HDI boards consist of insulating substrates and precision conductive circuit networks, serving as the core carrier for electronic hardware assembly. As a fundamental electronic substrate, it integrates with integrated chips, semiconductor discrete components, resistors, capacitors, connectors and other passive & active devices. Through standardized circuit interconnection, it realizes signal transmission, power distribution and functional collaboration between electronic components, acting as the core interconnect substrate for all electronic equipment.

As a basic electronic foundational material rather than a final end product, printed circuit boards have always had blurred conceptual boundaries in industrial cognition. For instance, desktop and notebook motherboards are typical finished assembly products, which integrate bare PCBs with numerous electronic components, making them essentially different from standalone circuit substrates. Similarly, media-referred integrated circuit boards are component-loaded assembly units, which cannot be equated with bare printed circuit boards in professional definition. It is critical to distinguish such related but non-equivalent concepts in professional PCB industry evaluation.

Driven by the miniaturization, multi-function and high integration trends of modern electronic devices, semiconductor chips feature increasingly compact pin spacing, while system-level signal transmission speed continues to increase dramatically. High-density circuit layout and shortened point-to-point signal paths have become mandatory design requirements. Limited by structural design and routing capacity, traditional single-sided and double-sided boards can no longer meet high-density wiring demands. Accordingly, multi-layer stacked PCB design has become the mainstream solution. The addition of independent power layers and complete ground layers effectively optimizes power integrity and return loop design, enabling multi-layer circuit boards to adapt to complex high-performance electronic system design.

For high-speed and high-frequency application scenarios, circuit substrates must meet strict AC impedance specifications, stable high-frequency transmission performance and effective EMI suppression indicators. The multi-layer structural design adopting microstrip line and stripline layout is essential to achieve these electrical performances. To minimize signal attenuation, delay distortion and transmission loss, low dielectric constant and low dissipation factor insulating materials are widely adopted in high-end board design. Meanwhile, the large-scale application of advanced packaging technologies including BGA, CSP and DCA further raises the threshold for PCB wiring density, driving high-density interconnected substrates to develop toward micro-sizing, array layout and ultra-fine line production.

In PCB manufacturing specifications, microvia is uniformly defined as holes with a diameter below 150μm. The microvia-based structural design is the core process feature of HDI boards, which greatly improves board space utilization, component assembly efficiency and three-dimensional interconnection capability. This core process technology has become an indispensable prerequisite for the lightweight and compact design of mainstream consumer electronics, wearable devices and precision industrial equipment.

In the early stage of high-density substrate development, regional manufacturers around the world adopted differentiated naming standards based on process characteristics. European and American suppliers named the sequential build-up manufacturing process as SBU; Japanese factories focused on micro-hole processing features and defined it as MVP micro-via technology; some manufacturers also used BUM to differentiate build-up multilayer boards from conventional MLB multilayer products. Diversified naming rules once caused confusion in technical communication and industry collaboration.

To unify global industry specifications and eliminate technical terminology differences, IPC formally took the lead in standardizing HDI as the unified technical term for high-density interconnection boards. As a universal international industry designation, HDI accurately summarizes the structural and process characteristics of high-density interconnected substrates. Currently, HDI board and high-density interconnection PCB have become the mainstream unified names in the global circuit industry.

Maxipcb® delivers comprehensive customized PCB solutions covering radio frequency, microwave and hybrid high-frequency composite boards, conventional FR4 double-layer and multi-layer boards, 1~3+N+3 stage HDI boards, any-layer HDI interconnection boards, rigid-flex composite boards, blind & buried hole boards, blind groove structural boards, backdrill boards, IC specialized substrates and heavy copper power boards.

Our diversified high-reliability circuit products are widely applied across multiple high-end industries, including Industry 4.0 intelligent manufacturing, communication infrastructure, industrial control automation, digital intelligent terminals, power energy equipment, computer hardware, automotive electronics, medical devices, aerospace equipment, precision instruments, military industry and IoT system equipment.