Multilayer PCB - Save Space & Increase Capacity for Your Products

multilayer pcb layout

Overview of Multilayer PCBs

  • Multilayer PCBs are one of the most advanced PCB types that PCBONLINE offers. In multilayer PCBs, there are at least three layers of copper that are separated by layers of insulation that are known as dielectrics.
  • The multiple layers of electrical circuits are superimposed on one another with reliable, predetermined connection points to prevent misalignment of the layers. This type of PCB saves space compared to simple one or two-layer PCBs while also enabling an extremely high density of components to be mounted in close proximity to one another. This type of design is used extensively in various professional electronic devices due to their versatility.

Advantages of Multilayer PCBs

Why Choose Multilayer PCBs from PCBONLINE

  • • We can produce multilayer PCBs with layer counts up to 100 layers!
  • • The width of traces are strictly controlled within tolerances of ±10%.
  • • The copper thickness plating of a hole is ≥20um which provides the best electrical conductivity.
  • • We use high quality materials with a high Tg by default to ensure high heat resistivity even when you may not specifically require it.
  • • Each layer is put under AOI to ensure the highest possible PCB quality.
  • • We have our own, in-house production line for the immersion gold process, which saves production costs and reduces the manufacturing time.
multilayer pcb

Multilayer PCB - Manufacturing and Tech Specs


Manufacturing Process

  • Below you can learn about how PCBONLINE produces your multilayer PCB in our standard process. The steps seems easy, but in-fact not many PCB manufacturers have quality control over the entire whole process like PCBONLINE does which makes PCBONLINE the best complex PCB supplier available.
  • Step 1. Cut lamination

    We will prepare each dielectric layer for the adhesive application process using polyimide or flexible materials respectively.

  • Step 2. Inner Layer Imaging

    In this step, we place the required circuit layout and design onto the resistive film layers for manufacturing of the inner layer.

  • Step 3. Lamination

    We then place copper layers and dielectric materials together after being positioned accurately and laminate them together into a single sheet known as a stack-up.

  • Step 4. Drill

    We will then drill through the stack-up of flexible and rigid materials as needed.

  • Step 5. Electroless copper deposition

    We then carry the panels that have your PCBs through a series of chemical and rinsing baths, and then plate the walls of drilled holes with micro-particles of palladium before deposit them with copper.

  • Step 6. Panel Plating

    At last we deposit the copper onto the surface of the circuit board, and inside the plated through-holes.

  • Step 7. Outer Layer Imaging

    We then use a dry film to image the required traces onto the PCB and then wash away the areas that don't need it.

  • Step 8. Pattern Plating

    We then deposit copper onto the board one more time to meet our clients’ copper thickness requirements. Then the board is plated with tin as a protective layer during etching in the next stage.

  • Step 9. Etching

    The dry film is washed away using chemicals, and copper is etched away etched away where it is not needed. Then we remove the protective tin layer from the circuit board to leave exposed copper.

  • Step 10. Solder Mask Applying

    In this step, the exposed copper of the PCB is coated using soldermask which is usually green and protects the PCB from short circuits and damage from the environment.

  • Step 11. Silkscreen Printing

    We then print the silkscreen legend, which is a layer of ink on the PCB to identify the components, test points, marks, and so on.

  • Step 12. Surface Finish Treatment

    The PCB is then coated with the required surface finishes to ensure solderability of components and to protect the copper circuitry from oxidation. At PCBONLINE, we have many types of surface finishes that are readily available: HASL, lead-free HASL, ENIG, OSP, immersion tin, immersion silver, hard gold plating, peelable mask, and carbon ink.

  • Step 13. Final Shaping

    We then cut the circuit board to its required size and de-panelize each PCB with either V-cut or routing.

  • Step 14. Tests

    Finally, all our PCBs go through a series of tests, including flying probe tests, the surface inspections, the dimension measurements, and the reliability tests. You can refer to our quality control for more information.


Tech Specifications

Leading manufacturing capability of leads to multilayer circuit boards of prominent quality. Here is the tech specs of our multilayer PCB:

Fabrication Process
Layer Count
HDI Stackup
1+N+1, 2+N+2, 3+N+3(with copper filling)
Final board thickness
Aspect Ratio
Laser via
Copper thickness
Single Ended
Inner Layer
External Layer
Min Drill Bit size
Hole Size Tolerance
Hole Position Tolerance
Solder Mask
Line to PAD
Surface Finish
Immersion Tin
Immersion Silver
Hard Gold Plating
Peelable Mask
Carbon ink
SMD 40-2000u", GND 30-800u"
Au 1-5u", Ni 80-200u"
Au 1-50u", Ni 80-200u"


  • You can use multilayer PCBs in a variety of industries. Applications where multilayer PCBs are widely used include the following:
  • 1. Computer Electronics:

    From servers to motherboards, multilayer PCBs are used in almost everything due to their high functionality and space saving benefits.

  • 2. Telecommunication:

    Devices in telecom often take advantage of multilayer PCBs such as mobile phones, satellites and GPS applications, due to all of their benefits and their ability to properly manage signal transmissions.

  • 3. Industrial:

    Multilayer PCBs are also popular in various industrial applications that run machinery. The most important industrial use for these designs is in controls machinery.

  • 4. Medical Equipment:

    In the health industry, electronics are an essential part of diagnosis through treatment. Multilayer PCBs can be used in medical testing devices such as CAT scan equipment, heart monitors, and modern X-ray devices.

  • 5. Defense and Military:

    Multilayer PCBs feature high functionality, durability, as well as being lightweight. Thus, they are desirable in military applications. Due to the increased movement of defense industry towards highly robust engineering designs, the need for multilayer PCBs is high due to their small size and high reliability.

  • 6. Automotive:

    Multilayer PCBs are also fit for the internal environments of automobile. They are used to manufacture automotive devices such as headlight switches, engine sensors, GPS's, and on-board computers.

  • 7. Aerospace:

    From ground computers to the cockpit, multilayer PCBs are always in consideration for their design manufacturing.

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We Make and Assemble the Ultimate Multilayer PCB out of Ingenuity and Rigour