In the ever-evolving world of electronics, the demand for high-performance, compact designs continues to rise. At Ring PCB, we specialize in the manufacturing of multilayer PCBs that meet the rigorous demands of modern applications for more than 16 years.
What Is a Multilayer PCB?
A multilayer PCB is a type of circuit board that consists of more than two conductive layers (copper layers). These layers are separated by prepreg, an insulating material also called a dielectric material, it melts and bonds the layers together under heat and pressure.
For instance, in a 4-layer PCB:
Layer 1: Top copper layer for routing signals.
Layer 2: Inner layer used as a ground plane.
Layer 3: Inner layer used as a power plane.
Layer 4: Bottom copper layer for additional signal routing.
The ground and power planes in the inner layers provide a stable reference for the signals and help to reduce noise and improve signal integrity. Meanwhile, the outer signal layers are used for routing various connections between components.
The number of layers in a multilayer PCB directly influences the board's complexity, cost, and performance. More layers allow for denser routing, better power distribution, and improved EMI shielding.
Our Multilayer PCB Manufacturing Process
1. Material Preparation:
Cutting the copper-clad laminate to the required size.
2. Inner Layer Imaging:
l Photoresist Application: A layer of photoresist (light-sensitive material) is applied to the laminate.
l Exposure: The photoresist-covered core is exposed to UV light through a photomask, which contains the design of the circuit pattern for that layer.
l Development: The exposed photoresist hardens, and the unexposed areas are washed away, leaving behind the circuit pattern on the copper surface.
l Etching: Removing unprotected copper to form the circuit pattern using chemical solution (usually an acid).
l Inner Layer Inspection: With automated optical inspection (AOI) , check the etched inner layer circuit patterns for defects.
3. Lamination:
Stacking and bonding the inner layers with insulating material under high temperature and pressure.
4. Drilling:
l Drilling Holes: Holes for through-hole vias, components, and mounting are drilled through the laminated stack.
l Laser Drilling: For microvias (small vias that connect only a few layers), laser drilling may be used due to its precision.
5. Hole Metallization (Copper Deposition):
Depositing a layer of copper inside the holes to create conductive pathways between layers.
6. Outer Layer Imaging:
The same as inner layer imaging, transferring the outer layer circuit patterns onto the copper-clad laminate.
7. Plating:
If used in high current applications, need to apply more copper to enhance electrical connectivity and circuit protection.
8. Solder Mask Application:
Applying a protective solder mask layer to the surface of the PCB to prevent short circuits during soldering.
9. Silkscreen Printing:
Print text, symbols, and labels for component placement and other instructions, and then the silkscreen is cured to ensure durability.
10. Surface Finish Application:
A surface finish (such as HASL, ENIG, or OSP) is applied to exposed pads and holes to protect the copper and ensure good solderability during component assembly.
11. Electrical Testing:
A flying probe tester or bed of nails tester is used to check the continuity and electrical performance of each circuit on the board.
12. Depanelization:
Separating the individual PCBs from the larger manufacturing panel using routing or V-scoring techniques.
13. Final inspection
l Visual Inspection: The boards are visually inspected for defects like misalignment, solder mask errors, or other physical issues.
l Quality Assurance: Final checks ensure that the boards meet the specified tolerances and industry standards (e.g., IPC standards).
l Product Slice: We will provide you with a PCB slice certificates that demonstrate the materials and techniques used in your PCBs, ensuring you receive a product that meets your requirements.
14. Packaging and Shipping
Check Our Multilayer PCBs Capabilities:
Feature | Specifications |
Number of Layers | Up to 40 layers |
Board Type | Multilayer Rigid PCB |
Rigid-Flex Multilayer PCB | |
Board Size | 600*770mm( 23.62″*30.31″) |
Board size tolerance | ±0.1mm – ±0.3mm(5%~10%) |
Board Thickness | 0.4mm – 8mm |
Board Thickness Tolerance | ±0.1mm – ±10% of thickness of board |
Min Tracing/Spacing | 3MIL/3MIL |
Min.Hole Size | 0.1MM |
Controlled Impedance | 5% |
Aspect Ratio | 16:1 |
HDI Capability | From 1N1 to N7N |
Min Blind/Buried hole size | 0.1mm(4-18 layers) |
Minimum Hole Size | 0.15mm (General), 0.075mm (HDI PCB) |
Impedance Control | Single-end and differential for multilayer |
Surface Finishing | ENIG |
OSP | |
Lead free HASL | |
Gold plating (hard gold) | |
Immersion Silver | |
Immersion Tin | |
Plating Tin | |
Other Techniques | Blind/Buried/micro-drilled/back-drilled vias |
Gold Fingers | |
Via in Pad- Epoxy filled and capped vias |
Lead Time of Multilayer PCBs
We provide rapid door-to-door delivery services to thousands of customers worldwide daily. Ring PCB collaborates with logistics companies like DHL, FedEx, and UPS to provide a wide range of shipping solutions. From air and sea freight to ground transportation, we can customize our services to meet your delivery needs. Please note that expedited shipping may incur additional fees.
Layer | 2 | 4 | 6 | ﹥8 |
Lead time | 24h | 48h | 72h | ﹤10days |
Advantages of Multilayer PCBs
lCompact Design: Multilayer PCBs allow for a higher component density, enabling more complex circuits to be integrated into a smaller footprint. This is particularly beneficial in devices where space is at a premium.
lImproved Performance: With shorter signal paths and reduced inductance, multilayer PCBs can enhance signal integrity and reduce electromagnetic interference (EMI), leading to better overall performance.
lExcellent Thermal Management: They also enhance thermal management by distributing heat more evenly across layers and can simplify routing by allowing multiple power and ground connections without additional space.
lBlind and Buried Vias: Multilayer designs facilitate the incorporation of advanced technologies such as blind and buried vias, which contribute to more efficient designs.
Applications of Multilayer PCBs
lConsumer Electronics: Smartphones, tablets, and wearables benefit from the compact and high-performance designs of multilayer PCBs.
lTelecommunications: Network equipment and communication devices rely on multilayer technology for efficient signal transmission.
lMedical Devices: Precision medical equipment often utilizes multilayer PCBs for their reliability and advanced functionality.
lAerospace and Defense: Multilayer PCBs are critical in high-stakes applications where performance and durability are paramount.
Ring PCB: Your Trusted Multilayer PCBs Manufacturer
At Ring PCB, we believe that quality starts at the beginning. By carefully inspecting your Gerber files, we can ensure that your PCBs are manufactured to your exact specifications, minimizing the risk of defects.
Benefit from our 16 years of expertise in multilayer board manufacturing, combined with our state-of-the-art manufacturing facility in Shenzhen, China, featuring cutting-edge technology and a dedicated team, ensures that your PCBs are produced with unmatched precision and reliability.
Are you looking for a seamless experience in PCB manufacturing, assembly, and component procurement? Look no further than Ring PCB. Our comprehensive services cover every aspect of your project!
