HDI PCB
HDI PCB professional manufacturing supplier
As a leading HDI PCB manufacturing supplier, we excel in delivering compact, high-density interconnect boards tailored for modern electronics. Embracing the trend towards miniaturization, our HDI PCBs ensure superior performance and functionality in a diminished footprint, catering to the evolving demands of the digital and electronics industries.
What is HDI PCB
HDI PCBs stand for High-Density Interconnect Printed Circuit Boards, characterized by a compact layout with an elevated number of connections within a smaller area, facilitating board miniaturization without sacrificing functionality. These boards, identified by having 120 to 160 pins per square inch, leverage advanced technologies such as microvias, blind and buried vias, and reduced drill sizes, allowing for closer component placement and efficient space use. Ideal for sophisticated, small-scale designs, HDI PCBs enhance device performance and electrical efficiency, making them pivotal for modern, fast, and compact electronic products.
You can learn about HDI PCB through the following video.
The Advantages of HDI PCB
HDI PCBs merge multiple board functionalities into a single, precise unit, offering enhanced design flexibility, denser component placement, and improved signal performance in compact layouts. Therefore HDI PCB has the following advantages:
Compact and Lightweight: The integration of more components into smaller spaces with HDI PCBs significantly decreases the overall size and weight of electronic devices, making them more portable and user-friendly.
Enhanced Electrical Performance: HDI PCBs ensure shorter distances between components, which results in faster signal transmission and reduced power usage, leading to enhanced device efficiency and battery life.
Cost-Effective: By utilizing fewer materials and consolidating functionalities into fewer layers, HDI PCBs reduce both the material and production costs, offering a more economical manufacturing solution.
Quicker Production Cycles: The streamlined design process of HDI PCBs facilitates faster assembly and testing, accelerating production times and enabling quicker market introduction of new products.
Increased Reliability: Employing microvias increases the HDI PCBs’ resistance to environmental stress and thermal expansion, thereby improving the durability and reliability of the final product under various operating conditions.
Superior Signal Integrity: The design optimizations in HDI PCBs, including minimized signal paths and the reduction of via stubs, significantly enhance signal quality and performance, especially crucial in high-speed electronic applications.
What are the applications of HDI PCBs?
Key Factors in HDI PCB Design
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Sequential Lamination: HDI PCB production often requires several rounds of sequential lamination, applying heat and pressure to bond the PCB core with copper and pre-preg layers. This meticulous process is essential for preventing shifts and breaks during via drilling.
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Via-in-Pad Process: Unique to HDI boards, the via-in-pad process integrates vias directly into the pad areas, enhancing thermal management and space efficiency. This intricate, multi-step method demands specialized skills and equipment for optimal implementation.
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Via Fill Types: Choosing the right via fill is critical, with options including non-conductive and conductive epoxies, copper, and silver fills. This decision impacts the board’s electrical performance and solderability, necessitating a match to specific PCB requirements.
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HDI Structures: HDI PCBs come in a variety of layouts, with common ones such as 1+n+1, 2+n+2, and ELIC (per-layer interconnect), all of which support dense component placement using microvias.These structures facilitate complex designs by allowing for staggered or stacked via configurations, enhancing connectivity within a compact space.
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Laser Drill Technology: Employing laser drills to create microvias is a hallmark of HDI PCB design, enabling the precision cutting of tiny holes through metal and glass. This advanced technology supports the high-density interconnectivity that defines HDI PCBs.
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LDI and Contact Imagery: HDI PCB fabrication leverages both laser direct imaging (LDI) and contact imagery to achieve fine line details and spacing. This precision is crucial for the dense layouts of HDI boards, requiring clean room conditions and meticulous process control to ensure defect-free production.
Features
Technical Parameters
Number of layers
4 – 22 layers standard, 30 layers advanced
Technology highlights
Multilayer boards with a higher connection pad density than standard boards, with finer lines/spaces, smaller via holes and capture pads allowing microvias to only penetrate select layers and also be placed in surface pads.
HDI builds
1+N+1, 2+N+2, 3+N+3,4+N+4, any layer / ELIC, Ultra HDI in R&D
Materials
FR4 standard, FR4 high performance, Halogen free FR4, Rogers
Copper weights (finished)
18μm – 70μm
Minimum track and gap
0.075mm / 0.075mm
PCB thickness
0.40mm – 3.20mm
Maxmimum dimensions
610mm x 450mm; dependant upon laser drilling machine
Surface finishes available
Immersion gold(ENIG), HASL lead free, Immersion tin, Immersion silver, OSP, Full board gold plating, Immersion gold + OSP
Minimum mechanical drill
0.15mm
Minimum laser drill
0.10mm standard, 0.075mm advanced
Soldermask / circuit processing method
Film, Laser Direct Imaging
HDI & Specialty Boards
HDI(1-7 steps), R-FPC(2-16 layers), High frequency mix-pressing(2-20 layers)
Different kinds of Vias in HDI PCB
In HDI PCBs, vias serve as small conductive pathways enabling signal transition across multiple layers. There are four primary types of vias utilized, each suited to different PCB functionalities: Through Hole vias, Blind Vias, Buried Vias, and Microvias.
Through-Hole Vias: These are drilled or lasered from the top to the bottom of an HDI PCB, linking all its layers. They are relatively simple to fabricate and are the most economical via option, categorized further into Plated Through Holes (with copper) and Non-Plated Through Holes.
Blind Vias: These connect an outer layer to an inner one and are only visible from one side, hence the name. Crafting blind vias is more complex and costly due to their accessibility from only one side.
Buried Vias: Exclusive to connecting internal layers of an HDI PCB, these vias remain hidden within the PCB structure and are not seen from the exterior, making them “buried”. They require an even number of layers for integration and a distinct drill file for plating.
Microvias: Characterized by their diminutive size, typically less than 150 microns in diameter, microvias are laser-drilled to connect adjacent PCB layers directly. Their compact size facilitates denser board designs, enabling more intricate circuitry on HDI PCBs.
Common different HDI PCB structures
HDI PCBs utilize two primary structures: Sequential Build-Up, where the core is assembled and sequentially laminated with drilling and filling processes, and ELIC for highly interconnected applications, allowing unrestricted microvia layer connections. The chosen stack-up and layer count directly influence the board’s design and functionality.The following is a common HDI PCB structure.
0+N+0: This basic setup involves no additional high-density layers beyond the core assembly, signified by “N”, with zero sequential layers on either side. Primarily used for simpler designs, it emphasizes a cost-effective approach while keeping the production straightforward and minimizing expenses.
1+N+1: Introducing an extra layer of high-density interconnections on both sides of the core, this design supports improved functionality for moderately complex devices. It’s ideal for devices requiring a balance between higher performance and manageable costs, enhancing stability and reliability for BGAs with fewer inputs/outputs.
2+N+2: Incorporating two high-density layers atop the base, this configuration allows for intricate design capabilities and enhanced signal transmission. It’s tailored for devices needing extensive routing in compact spaces, supporting high I/O count BGAs with its sophisticated structure that still maintains a slim profile.
ELIC (Every Layer Interconnection): The most advanced HDI setup, ELIC, enables complete freedom in layer-to-layer connectivity with copper-filled stacked microvias across all layers. This architecture is key for cutting-edge applications in CPUs and GPUs, offering unparalleled electrical performance and connectivity for high-pin-count devices in mobile and handheld technology.
Considerations Regarding the Expense of HDI PCBs
Different factors will affect the cost of HDI PCB. Please determine your budget based on the following conditions to obtain the maximum benefit from use.
- Via Selection and Quantity: The type and number of vias, including microvias or through-holes, significantly influence HDI PCB costs. Smaller, more precise vias typically raise expenses, as does increasing their quantity.
Layer Structure and Complexity: Costs vary based on the stackup configuration; more complex setups like 2-n-2 layouts are pricier than simpler 1-n-1 configurations. The optimal, cost-efficient layer count should be targeted.
Material Choices: The choice of core material and finish affects price. ENIG often prevails for HDI boards due to its soldering benefits and surface flatness.
Sequential Lamination Needs: The requisite number of laminations, dictated by layer count and via types, affects processing time and costs. Strategic lamination can enhance both performance and cost-efficiency.
Vias Configuration: Cost discrepancies exist between stacked and staggered vias, with stacked options requiring copper filling, thus increasing material use and production time.
Pad Size Planning: Early determination of pad sizes can aid in reducing costs by facilitating more efficient and economical design planning.
CONTACT US
For customers who require new products with complex circuit boards and have tight release schedules, we provide technology and expertise from prototype to production. You can contact us through the methods below to discuss your project with our technical experts immediately. We will be in touch within 24 Reply within hours.
If you already have documentation for your PCB or PCBA related needs, please submit a quick quote for a free evaluation.
