Premium Multilayer PCBs at Competitive Prices
- Variety of Options: Rigid, Flex, Rigid-Flex, HDI, High TG, High-Speed, High-Frequency, Backplane, Embedded PCBs, IC Substrate
- Production Capacity: 4-40 Layers for Mass Production & up to 100 Layers for Prototypes
- Vias Technology: Blind & Buried Vias, Staged & Staggered Vias, Back Drill
- Via Plugging: Conductive & Non-conductive Via Plugging, VIAPPO
- Certification: ISO9001:2015 Certified & UL Listed
- Quality Assurance: 100% E-test, AOI Testing & Visual Inspection
As the electronics and semiconductor sectors expand rapidly, the demand for advanced technology in devices increases. Initially, cell phones were limited to making and receiving calls, but today’s smartphones leverage multilayer PCBs to support a wide array of applications. These sophisticated boards facilitate the mounting of numerous SMD and DIP components, enhancing device functionality and enabling the development of complex electronic devices.
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What is a Multilayer PCB?
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A multilayer PCB is defined as a printed circuit board containing more than two copper layers, unlike single or double-layer PCBs which have just one or two. Typically, multilayer PCBs range from 4 to 18 layers, and in specialized applications, they can even exceed 100 layers. The outer layers of a multilayer PCB are referred to as the top and bottom layers, while the inner layers serve various functions, including signal, power, and ground planes. These layers are interconnected using through-hole drills, blind vias, and buried vias, facilitating complex electronic connections.
The construction of multilayer PCBs resembles a sandwich, comprising inner layers, dielectric cores, and prepregs. For a clearer understanding of multilayer printed circuit boards and their connectivity, refer to the diagram below, which illustrates how inner layers are placed on the dielectric prepreg and core.
Main Components of Multilayer PCB
- Core: The conductive copper layers that transmit electrical signals and distribute power within the multilayer circuit board.
- Prepreg: The insulating material that interconnects cores and layers in the PCB stackup.
- Copper Foil: The initial copper thickness applied to both inner and outer layers of a multilayer PCB.
- Solder Mask: A protective film that safeguards components on multilayer circuit boards from external factors such as oxidation and corrosion.
- Surface Treatment: This process enhances the exposed copper surfaces during multilayer PCB fabrication, preventing short circuits and oxidation.
- Vias: Holes that facilitate electrical connections between various layers of a multilayer circuit board, including through holes, blind vias, buried vias, and back drill vias.
Different Types of Vias in Multilayer PCB
Through Hole Drills (Vias):
These connect all layers from top to bottom.
Blind Vias:
Connect the top or bottom layer to the inner layers.
Buried Vias:
Connected exclusively to inner layers, not to outer layers.
Stacked Vias:
Connect from outer to inner layers in a straight line for optimal routing.
Staggered Vias:
These connect to adjacent layers at an angle rather than in a straight line.
Micro Vias:
Smaller than 0.15mm, commonly found in HDI multilayer PCBs.
Advantages of Multilayer PCB
The primary advantage of multilayer PCBs is the ability to house more components and functions within a compact area. As electronic components shrink in size, designers can utilize multiple layers to minimize PCB dimensions while maximizing functionality. Here are some key benefits:
- Size Reduction: Multilayer PCB designs enable significant size reduction using inner layers.
- High Component Density: Increased component density is achievable with multilayer PCBs.
- Enhanced Functionality: More connections allow for greater functionality in electronic components.
- Powerful Performance: High-power components can be integrated for superior performance.
- Thermal Efficiency: Multilayer PCBs offer excellent thermal conductivity.
- Mechanical Strength: They provide robust mechanical support for heavy components.
Disadvantages of Multilayer PCB
- Complex Procedures: Manufacturing multilayer PCBs involves lengthy processes.
- Increased Costs: The complexity of multilayer boards often leads to higher manufacturing costs.
- Extended Manufacturing Time: Production times can be lengthy, though some vendors may expedite the process.
Manufacturing Process of Multilayer PCB
The production of multilayer PCBs involves several specialized processes tailored to meet specific requirements. Here’s a typical production workflow:
- DFM Check: All layers undergo verification by a DFM engineer to identify and correct errors.
- Material Selection and Cutting: Appropriate materials are selected and cut based on order specifications.
- Automated Optical Inspection (AOI): The circuitry images are converted to digital formats for defect inspection, verified by a manual inspector.
- Lamination: Inner copper foil, cores, and prepregs are bonded under heat and pressure to create solid layers.
- Drilling: Various drilling types are performed according to specifications, including blind and buried vias.
- Copper Plating: PCBs are submerged in a copper plating bath to enhance thickness and durability.
- Outer Layer Process: Similar to inner layers, outer layers are processed with image transfer and etching.
- Masking and Legend Printing: Solder mask and silkscreen are applied for component protection and identification.
- Surface Finish: Applied based on customer specifications to enhance solderability and testing.
- Electrical Testing: Verifies all connections to identify shorts or breaks using electrical testing machines.
- Routing and Scoring: Custom shapes require routing or scoring to facilitate depanelization.
- Final Inspection and Packing: Completed boards are inspected and packaged for shipping.
Why Choose Multilayer PCB from ESPCBA?
The multilayer PCB manufacturing process is intricate, presenting challenges for manufacturers. When selecting a reliable multilayer PCB supplier, consider factors such as reputation, technology, equipment, and industry experience. ESPCBA is a trusted Chinese multilayer PCB supplier, offering flexible, customer-oriented solutions tailored to specific needs. By choosing us, you benefit from:
100% Quality Guarantee
Over 98% On-Time Delivery Rate
Minimum Order of Just 1 Piece
Comprehensive Contracting Services
Flexible Customization Options
If you have further inquiries about multilayer circuit boards, feel free to contact us. We look forward to collaborating with you!
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Looking for reliable SMD assembly services? At ESPCBA, we’re your trusted partner for PCB fabrication, component sourcing, and electronic manufacturing. With over 16 years of experience, we’ve provided high-quality PCBs at competitive prices to over 1,000 customers worldwide. Our company is ISO9001:2015 certified and UL listed, and every product we deliver is 100% E-tested and inspected using AOI and X-ray to meet the highest standards. Get an instant quote from our sales team today, and let us handle the rest for you.
Frequently Asked Questions
- Rigid multilayer PCB
- Flexible multilayer PCB
- Rigid-flex multilayer PCB
- HDI multilayer PCB
- Buried and blind via multilayer PCB
- Heavy copper multilayer PCB
- 4-layer PCB, 6-layer PCB, etc.
- Core materials
- Prepreg
- Copper foil
- Inner layer copper trace → Lamination → Drilling → Outer layer copper trace → Copper plating → Solder mask printing → Surface treatment → Silkscreen printing → Profiling → E-test → Quality inspection → Packaging after cleaning.
Cost varies based on factors like base material type, dimensions, layer counts, copper thickness, board thickness, layup structure, surface finishes, and special technology.
Used in industrial controls, automation, robotics, telecommunications, smartphones, smartwatches, calculators, kitchen appliances, washing machines, e-cigarettes, LED bulbs, motherboards, graphics cards, and more.
- Keep the power layer close to the ground plane.
- Place wiring layers adjacent to the metal plane.
- Separate clock and high-frequency circuits from sensitive components.
- Address varying stray and high-frequency currents across different layers.
Selecting the right multilayer PCB supplier can significantly lower costs. ESPCBA offers high-quality multilayer PCBs at competitive prices. Choose us as your multilayer PCB partner for the best value.