World Class Custom Multilayer PCB Manufacturer in China

PCBMay is a Professional Multilayer PCB Boards Manufacturer in China,Who Provides Many Different Kinds of Multilayer Boards.

Printed Circuit Boards (PCB) are an integral part of almost all electronic applications. Without PCBs the electronics industry can’t manufacture products. But what manufacturing techniques make these PCBs robust enough to hold circuits and run them smoothly? On commercial scale, PCB manufacturing is quite detailed and involves extensive use of technical procedures.

The Multi layer PCB manufacturing process starts with Computer Aided Design (CAD) of the circuit, later, this design is printed on to the PCB and the copper layers are removed from unwanted regions. The board is drilled for through-hole components. Later the board goes through testing and once clear, it is ready for component assembling. The procedure varies depending upon the type of PCB and components.

Many Advantages of Multilayer PCB Boards

Over 12 years multilayer PCB manufacturing experience.

Over 80 technical engineering to support your electronic development and manufacturing.

No MOQ for new orders,even one piece.

Quick turn/express order within 24hours.

100% E-test and AOI inspection.

UL,RoHs,REACH and ISO Certifications.

Providing Micro-section,soldering sample and COC report.

Shipping by international forwarder UPS,Fedex,DHL.

7/24 online support for your business.

4layer pcb

4 layer PCB

The 4 layer PCB is very popular and 4 layer stackup is quite elaborate. Two inner layers, inner layer 1 and 2, are sandwiched between the top and bottom layers.There're 4layer rigid boards or 4layer flex PCBs or 4layer flex-rigid PCBs.

6layer pcb

6 layer PCB

The 6 layer PCB stackup is very populer,normally,there're top signal,inner signal,ground plane,power plane,inner signal and bottom signal,what's more,sometimes there're differ or single impedance controls among the layers.

8layer pcb

8 layer PCB

The 8 layer PCB stack-up offers ample routing space for multiple power islands. All signal layers have a minimum of one referencing power plane. The power and ground layer in the center offers good inter plane capacitance.

10layer pcb 02

10 layer PCB

The 10 layer PCB board is a circuit board that has 10 layers. They are fixed tightly together with strong mutual relations between each of the layers. PCBMay has much more experience in making multilayer boards such as 10 layer PCB.

12layer PCB

12 layer PCB

The 12 layer PCB board offers the foundation for a modern automotive electronic circuit,12layer stack up deals with specific requirements for tracking heights and material thickness in producing multi-layer Printed Circuit Board.

14layer PCB

14 layer PCB

PCBMay can help you design custom 14 layer rigid printed circuit boards with the standard FR4 or high TG170 materials,even 14 layer with flex-rigid PCB with polyimide material,please don't hesitate to send RFQ to our sales@pcbmay.com.

16layer PCB

16 layer PCB

16 layer PCB is not like standard type of PCB,it consists of multiple layers and uses different prepregs and cores to laminate together,normally it is made from halogen-free material and the board thickness will be reached to be 7.0mm.

18layer PCB

18 layer PCB

At PCBMay, 18 layer rigid-flex PCB with 12 layer flex PCBs are produced in a wide range of board materials. A few amongst them include FR4 (Tg – 135C, 145C, 170C), Rogers Ultralam 2000, Polyimide, Teflon, Black FR4, Arlon AR350,etc.

20layer PCB

20 layer PCB

20 Layer PCBs are High Density Interconnect board with huge width and space, holes are more than 0.3mm. Our experienced team can manufacture the 20 Layer PCB with four planes and 6 signal layers.

22layer PCB

22 layer PCB

22Layer PCB Stack up with Nelco 4000-13EP for all layers except layers 10-11 and 12-13 which requires MITSUI MC24M material,Surface finishing: Immersion Gold(3u''),Min trace width/spacing:6 /6 mil,Finished copper thickness: 2oz,Min hole size: 0.2mm

24layer PCB

24 layer PCB

24 layer boards for high density interconnects and backplanes are common, with around half being power and ground planes, with the rest being controlled impedance signal lines.

30layer PCB

30 layer PCB

The Capability of PCBMay is 1 – 24 layers standard, 30 layers advanced, 40 layers prototype,you will find more information from our capabilities in our webpage.

32layer PCB 02

32 layer PCB

Thickness: 4.8mm Surface finishing: LF HAL, Min trace width/spacing: 5 /5 mil, Finished copper: 1oz,Min hole size: 0.4mm,Materials: MEGTRON 6,Aspect Ratio:12

36layer PCB

36 layer PCB

Thickness: 6.0mm, Surface finishing: Immersion Gold, Min trace width/spacing: 4 /4 mil, Finished copper thickness: 2oz for outer layer,3oz for inner layer, Min hole size: 0.4mm.

40layer PCB

40 layer PCB

PCBMay can produce the prototypes of 40layer PCB,what's more,the the stack up of 40layer is very complicated,meanwhile,the delivery is much longer than standard PCBs.

Frequently Asked Questions (FAQ) About Our Multi layer PCB Boards Process and Capabilities

Here you will find many quick questions and answers about multi PCBs,don’t hesitate to contact us,our email is sales@pcbmay.com.

We can produce from single layer,double layer,multilayer PCB unitl 40layers.

Multilayer PCB is a circuit board that has more than two layers. Unlike a Double-Sided PCB which only has two conductive layers of material, all multilayer PCBs must have at least three layers of conductive material which are buried in the center of the material.

To produce a multi-layer PCB, alternating layers of epoxy-infused fiberglass sheet called prepreg and conductive core materials are laminated together under high temperature and pressure using a hydraulic press. The pressure and heat causes the prepreg to melt and join the layers together.

Using a bright light, it’s easy to see if a board has inner layers even if it doesn’t have blind vias. Find some place on the board where there aren’t traces/planes on the visible, outer layers and see if you can see light through it. If it’s blocked in some places, that’s probably copper.

We can produce the prototype of multi layer boards with quick turn 48h and one week for standard leading time,2-3 weeks for mass production of multilayer PCBs.

Our standard color for soldermask is green. We can also provide soldermask in red, white,yellow,purple,blue or black,also matte green,matter black,matter red or matter blue  for an additional amount.

The largest size PCB we can produce is 43″ x 19″ or 1100mm x 500mm.

The standard board thickness is 1.6mm , this provides a good balance between strength and weight. A thickness of 2.4mm or 3.2mm is also available.

The copper thickness of most PCB boards is 35um(1oz),our capability can reach 12oz.

No,we can produce 1 to 10,000 pieces,what’s more,there is also no minimum order surcharge or additional fees

A multilayer PCB is a board that has a conductor layer (inner layer) inside the board. In addition to the component side and the solder side, and is usually used for a power supply system. As a result, the low impedance due to the wide pattern area and the parallel plate capacitance between the power supply layers form a decoupling effect.

Multilayer PCB 1

What is the Difference Among Various PCB Boards Layers?

The structure of the printed circuit board depends on the number of mounted components.

If it is sufficient to mount the components on only one side of the board,it will be a single-sided board. And if you want to mount it on both sides, it will be a double-sided board. Single and double sided circuits: things to know.

What is Single Layer PCB?

When we talk about a ‘monolayer’ circuit, we are referring to the simplest model, the single-sided one: it requires that there is a layer of material, with conductive tracks that wind on a single side.The most interesting elements relating to this type of circuits are those relating to the ease of assembly and the reduced costs as regards machining operations.

These are products that are used,for example, in household appliances and in general are perfect for projects linked to large consumption. Even intervening to repair the equipment,in the presence of single-sided circuits, is easier.

What is Double Layer PCB?

On the other hand, we take into consideration the double-sided circuits (those with two layers) they appear to be more flexible and with a decidedly reduced board size:they are probably the most common on the market.

Multilayer PCB 5

Thanks to them – and their wide application flexibility – many and distinct needs can be interpreted in any technological field. The reference is in particular to electronics for motors, but also to the IT and electro medical sectors.

Since it is possible to exploit the two faces,an optimization of spaces is configured and consequently an interesting reduction of costs. With regard to these printed circuits, we should not overlook the wide possibility of customization,linked to the customer’s needs and the relative budget available.

What is Multilayer PCB

It may happen that a single or even a double layer is not sufficient to satisfy certain application needs.The solution, in this case, is represented by the use of multilayer PCB.

The latter,of course, see the presence of a variable and higher number of layers of material:from 4 layer,6 layer,8layer and more layers.In these particular products the tracks cross the layers, which allows to optimize the available space?This results in an interesting and greater compactness of the circuit. This latter aspect is particularly interesting in the case of devices with small dimensions.

Multilayer PCB 8

How to Design Multilayer PCB?

By patterning the board in multiple layers,the pattern is placed in the inner layer,increasing the area where components can be mounted.This is the advantage of the multilayer PCB board.

The through holes used in the two-layer board will be connected to the inner layer if left untouched.Therefore, in the case of through holes such as signal lines that do not connect to the inner layer, it is necessary to provide a pattern that do not connect to the inner layer.

Also, when it is desired to connect to the inner layer such as the power supply system,if such a pattern is not provided, the through hole is directly connected to the conductor of the inner layer. So the connection is made.

However,in such a connection,when soldering by inserting the component into the through hole there,it is difficult to solder because heat does not easily transfer.Therefore, so-called thermal pads that are connected in a cross pattern.

How Are Multilayer PCBs Manufacturing?

Multilayer PCB – A PCB consisting of multiple layers of dielectric with conductive patterns between the layers and on the outside.

Manufacturing of multilayer printed circuit boards consists of creating separate layers according to the technologies of single and double-sided boards and their subsequent joining by pressing.The layers are joined using a specialized sheet material based on resin – prepreg,which has adhesive properties.

Switching of conductors of different layers is carried out using plated holes, which can be through, hidden (when switching two or more layers inside the board) or blind (when switching one outer layer with one or more inner layers).

The number of layers in multilayer boards is limited by the:

  • Overall board thickness
  • The ability to align layers
  • The reliability of the plated holes

Multilayer PCB with about 20 layers are widespread.

Multilayer PCB 9

Multilayer Printed Circuit Board Manufacturing Process Steps

On a commercial scale, Printed Circuit Board manufacturing involves a series of extensively technical steps. From design to development, each step is carried out according to the defined industrial standards. The following steps are the major phases a PCB goes through before it is ready for assembling components.

Step 1: Design and Layout Development

PCB manufacturing starts with the development of the circuit’s soft layout using commercial software like Altium. The designer creates a simulation of circuit design for extracting the CAD of the circuit. When designing a PCB layout, one should take care of certain things, such as the route width, elements, and position. Each detail requires extensive care; even a slight mistake can cause PCB malfunctioning.

On the commercial scale, PCB designing tools are available in a wide range. The designers usually extract PCB designs in Gerber format. It encodes all the details, such as the number of copper layers, the number of masks required for soldering, and all other notations. When the program simulates a design, all the details can be easily inspected.

PCB Design

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Step 2: PCB Design Printing

The PCB design can be printed after all inspections are complete. Contrary to other plans, PCB prints do not appear on a standard paper, such as the engineering drawing. A plotter printer produces the PCB film. The plotter uses extremely accurate printing machinery to deliver an extensive film of the design.

Two ink colors represent the inner layer: First is black ink used in copper paths and PCB circuits, and the second one is clear ink, which represents the PCBs non-conductive areas and fiberglass base. This mode is reversed in the case of outer layers in which clear ink refers to the copper pathway line, but black ink shows regions in which copper is removed.

Every layer of the PCB and the corresponding solder mask is given a film, so four sheets are needed for a simple two-layer PCB — one for every layer and the one apiece for each solder mask. After the film is printed, it’s all lined up, and a hole is drilled in it, known as a registration hole. The recording hole is a reference for the later alignment of the films.

Step 3: Inner layers Printing

The copper is pre-connected to the same laminate portion after the PCB design is printed on the laminate and used as the PCB structure. The copper is then etched to display the blueprint of the earlier edition. Then, a photo-sensitive film called resist is covers a laminate panel. The resistance is made of a layer of photo-resistive chemicals that hardens when exposed to ultraviolet light. It enables the developers to precisely match the position of blueprint images with those printed to the photoresist.

After alignment of resist and laminate, they absorb ultraviolet light. The ultraviolet light passes the translucent sections of the film, which hardens the photoresist. It exposes the copper patches that need to be kept as pathways. The black ink prevents light from reaching areas that are not to be hardened. This ink is removable.

Inner Layer image

                                                                                                                               Inner Layer image

Step 4: Unwanted Copper Removal

Once the wanted and unwanted copper patches are market, the unnecessary copper removal begins. The board is submerged or treated with an alkaline solution which reduces the copper strength and eats it off. All exposed copper is extracted in the copper solvent solution bath. In the meantime, under the hardened layer of photoresist, the desired copper is entirely safe and covered.

But since PCB come in a variety of substrates and not all copper PCBs are the same, the process can slightly vary depending upon the concentration of copper. Short-heightened boards need more copper solvents and different exposure lengths whereas large copper boards need more consideration in the spacing of the track. Now that the solvent has eliminated the unwanted copper, the hardened resist safeguarding the remaining copper requires washing. Another solvent carries out this job. With just the copper tracks available on PCB, the board now starts appearing in desired shape.

Step 5: Board Inspection and Layer Alignment

Once the board is thoroughly cleaned, the board needs to be inspected. For aligning the inner and outer layers, the holes are used. The developer punches the board using an optical punch to align the layers. The punch pushes in a pin through the holes to match the PCB layers.

The Automated Optical Inspection (AOI) machine is used for inspection afterwards to ensure that there are no faults. This is an extremely critical step since any defects that occur can never be resolved until the layers are permanently binded. The machine compares the inspected PCB to an extended Gerber version for further confirmation. After the PCB passes the AOI inspection, it qualifies for the layers’ lamination stage.

Step 6: Layer Lamination

PCB lamination is performed in two stages: the lay-up step and the lamination step. The external part of the PCB is made from fiberglass pre-soaked with an epoxy resin. A thin copper foil layer, which now contains gravures for the copper traces, is filled with the original substrate. When external and internal layers are ready, it is time to bind them.

The sandwiching is performed on a special press table with metal clamps. Using special screws, each layer is fitted onto the table. The manufacturer begins by inserting pre-impregnated resin, also known as prepreg resin on the table alignment basin. On the other side, the copper foil comes along with other sheets of pre-impregnated resin that are finished with a strip of cotton.

Now the stack is ready to be pressed once the copper press plate is in place. The manufacturer passes it to a mechanical press and pushes down, together with the layers. Then, the pins are forced down through the layer stack to make sure they are accurately fixed.

The PCB stack is then taken to the next press, a laminating press where the layers are adjusted. The lamination press uses a pair of heated plates to apply heat and pressure for the stacking of layers. The epoxy within the prepreg melts by the heat of plates, and by fusing the piles together. Once the layers of the PCB are pressed together, a little unpacking is required. The technician has to remove the top press plate and the pins to release the PCB.

Step 7: Drilling

Before the drilling begins, an X-ray equipment is used to detect drill spots. Registered holes are then drilled to protect the PCB stack until individual holes are drawn. When it comes to drilling these holes, a computer-guided drill is used as per the design of the extended gerber file. Upon drilling completion, any copper that remains at the boundaries is extracted.


                                                                                                                                    PCB Drilling

Step 8: Copper Plating

After the PCB is drilled, a chemical is used for fusing together all layers of the PCB. Later, the PCB is bathed in a variety of chemicals after being thoroughly washed. The panel is then coated with a micron-thick copper sheet put on the top layer and in the holes only drilled. They are used to expose the fiberglass substrate; making up the panel’s insides before the holes are filled with copper. The copper holes in the walls of the previously drilled holes are bathed.

VCP Plating Line

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Step 9: Imaging and Photo-resistive Plating

In this phase, a new layer of photoresist is applied but only to the external layer since it still has to be imaged. After the exterior layers are coated in photoresist and imaged, the internal layer of the PCB is plated precisely as in the last stage. However, the outer layers receive the same process as a tin plate to guard the copper against the external layer.

Step 10: Etching

Before the external layer is etched, a tin guard is used to secure copper. The unwanted copper is eliminated using the same copper solvent which was used earlier. After the etching process, the PCB connections are set correctly and it is ready for solder masking.

pcb etching

                                                                                                                                            PCB Etching

Step 11: Solder Masking

The panels are washed to ensure that they are ready for use. After cleaning the PCB plates, an ink epoxy and a solder mask film are added. The panels are exposed to ultraviolet light to differentiate certain areas of the solder mask. The PCB is then put into an oven and warmed so that the solder mask may cure after the undesirable pieces of solder.

Soldermask Process

                                                                                                                             Soldermask Process

Step 12: Surface Finishing

This stage involves chemically plating the board with gold or silver to add an additional solder capability to the PCB. During this point, some PCBs also receive hot air pads. Appropriate level of hot air helps maintain uniform pads. This process ends with a smooth surface finishing.

Immersion Gold

                                                                                                                                     Immersion Gold

Step 13: Silkscreening

The silk-screening process labels all the critical information on the PCB. For example, the manufacturer remarks, company ID number, and warning labels. It is necessary since the PCBs have to be assembled, tested, and maintained in the future; the labeled information helps locate component positions.

Step 14: Electrical Testing

After the PCB goes through all above steps, it qualifies for an electrical test to ensure its functionality. Mainly, the circuit continuity and insulation tests are performed. The continuity test checks if all short-circuit connections are closed (as needed), whereas the circuit insulation test checks the different sections of the PCBs that are designed to be insulated. While electrical tests are primarily designed to guarantee functionality, they also evaluate how well the initial PCB design was supported in the production phase.

Auto E-Tester

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Step 15: Scoring and Profiling

Cutting and scoring the PCB is the last step in the manufacturing process, and then the PCB goes through a final test. The PCB can be cut from the original panels in two ways: First, using CNC equipment (which cuts tiny tabs around PCB edges), and the second one is using a V-groove, (which cuts the diagonal channel along the board sides). PCB panels are usually routed and scored out with a single board or larger arrays, where necessary, to split off the board after assembling. 

Till this step, the PCB has been just manufactured, it still needs to be assembled with necessary components for complete functionality. Moreover, after assembling the PCB goes through a series of tests to ensure it functions as needed. Evidently, PCB manufacturing is an extensively technical process.

Routing PCB

                                                                                                                            Routing PCB Machines

Step 14: Vacuum Package

“PCB circuit board packaging” is crucial to the procedure, with moisture sensitive requirements, packaging requirements of sealing, desiccant, pumping air into vacuum state, but a lot of PCB company for this final process didn’t pay attention to, so a lot of the work is simple, using the PCB are not under good protection, leads to problems such as PCB board surface is easy to damage or friction.

Packing PCB

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What are the Major Applications of Multilayer PCB Boards?

Multilayer PCB (PCBs) are used to design complex devices that require high component density.The number of layers depends entirely on the complexity of the task of the PCB designer.Computers,File servers,Data storage,Signal transmission, Cell phone transmission, Cell phone repeaters, GPS technology, Industrial controls, Satellite systems, Hand held devices, Test equipment,X-ray equipment, Heart monitors, Cat scan technology, Atomic accelerators ,Central fire alarm systems, Fiber optic receptors, Power supply, Medical devices, Nuclear detection systems, Space probe equipment, Weather analysis, etc.

Multilayer PCBs can contain up to 40 layers.It provides a high specific density of printed conductors and pads.Other advantages of printed circuit boards of this type include the reduction in the length of the conductors.

A multilayer printed circuit board consists of a series of superimposed layers.In which are formed connecting conductors for transmitting signals,conductive surfaces for supplying voltages, grounding circuits,and pads or tabs for connecting leads.

Often, a heat-conducting material is included in the structure of a multilayer board for cooling.A connector is installed on one of the edges of the board.

It significantly increases the speed (for example, the speed of data processing in a computer).Also multilayer printed circuit boards allow shielding of AC circuits.

1) Dielectric.
2) Protective layer (mask).
3) Contact hole.
4) Conductive track.

PCBMay is an Experienced Multilayer PCB Manufacturer

PCBMay has been producing Multilayer PCBs for over 12 years. Over the years, we have seen all types of multilayer constructions from various industries, answered all types of multilayer questions, and solved all types of problems with multilayer PCBs.

Layer Count1-40layers
Base MaterialKB、Shengyi、ShengyiSF305、FR408、FR408HR、IS410、FR406、GETEK、370HR、IT180A、Rogers4350B、Rogers4000、PTFE Laminates(Rogers series、Taconic series、Arlon series、Nelco series)、Rogers/Taconic/Arlon/Nelco laminate with FR-4 material(including partial Ro4350B hybrid laminating with FR-4)
Board TypeBackplane、HDI、High multi-layer 、blind&buried PCB、Embedded Capacitance、Embedded resistance board 、Heavy copper power PCB、Backdrill.
Board Thickness0.2-5.0mm
Copper ThicknessMin. 1/2 OZ, Max. 10 OZ
PTH Wall25um(1mil)
Maximum Board Size1100*500mm(43”*19”)
Min laser drilling size4mil
Min. Spacing/Tracing2.7mil/2.7mil
Solder MaskGreen, Black, Blue, Red, White, Yellow,Purple matte/glossy
Surface TreatmentFlash gold(electroplated gold)、ENIG、Hard gold、Flash gold、HASL Lead free、OSP、ENEPIG、Soft gold、Immersion silver、Immersion Tin、ENIG+OSP,ENIG+Gold finger,Flash gold(electroplated gold)+Gold finger,Immersion silver+Gold finger,Immersion Tin+Gold finge
Min. Annular Ring3mil
Aspect ratio10:1(HASL Lead free、HASL Lead、ENIG、Immersion Tin、Immersion silver、ENEPIG);8:1(OSP)
Impedance control±5ohm(<50ohm), ±10%(≥50ohm)
Other TechniquesBlind/Buried Via
Gold Fingers
Press Fit
Via in Pad
Electrical Test
Customers Testimonials

See What Our Customers Say

Our goal is to make our customers be satisfied with their quality.Since 2008,we've been manufacturing printed circuit boards and assembly for our customers. We will help you make your PCBs from prototype through production from layout to finished product, on time and within spec.

I’ve been using PCBMay for some years now, and just like all the projects I’ve done with PCBMay, there were no surprises. Everything went just as it was supposed to, and the board is performing fine. You’re lucky to work for such a great company.What's more,we're working with them for many different multilayer boards,excellent service.

Shirley Malhotra
Design Engineer

We consider PCBMay a partner rather than a vendor. We have worked with many PCB or assembly vendors over the years and have moved all of our business to PCBMay as their quality and on-time delivery are unmatched. They manufacture different PCBs and assemblies, and the level of expertise that PCBMay has in both the PCB fabrication and assembly has had a positive, meaningful impact on our business.

Kylo James

PCBMay has always been very responsive in meeting our quick-turn PCB fabrication and board assembly schedules for several years while at the same time focusing on delivering quality products. Our experience in dealing with PCBMay sales has been very positive.

Linda Perez
Purchasing Coordinator

The boards are great and they work perfectly. We look forward to doing more business with you in the future. We are in the process of re-designing some of our existing boards and will definitely be giving you the opportunity to quote on them.

Ella Ross
Hardwear Developer

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