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:

lPhotoresist Application: A layer of photoresist (light-sensitive material) is applied to the laminate.

lExposure: The photoresist-covered core is exposed to UV light through a photomask, which contains the design of the circuit pattern for that layer.

lDevelopment: The exposed photoresist hardens, and the unexposed areas are washed away, leaving behind the circuit pattern on the copper surface.

lEtching: Removing unprotected copper to form the circuit pattern using chemical solution (usually an acid).

lInner 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:

lDrilling Holes: Holes for through-hole vias, components, and mounting are drilled through the laminated stack.

lLaser 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.

111.  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

lVisual Inspection: The boards are visually inspected for defects like misalignment, solder mask errors, or other physical issues.

lQuality Assurance: Final checks ensure that the boards meet the specified tolerances and industry standards (e.g., IPC standards).

lProduct 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:

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.

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.