HDI PCB – High Density Interconnect
Rayming HDI Capability: 1+N+1, 2+N+2, 3+N+3,4+N+4, any layer connect, R&D Support
High Quality high-density interconnect PCB Manufacturing, blind via or/and buried hole, accept any layer of the PCB to be interconnected freely.


About HDI PCB
High density interconnect (HDI) PCBs enable denser routing, finer lines and spaces, smaller vias, and more layers than conventional PCBs. They are essential for miniaturized and high performance electronics like smartphones, wearables, IoT devices, automotive electronics, and medical devices.
Selecting the right HDI PCB manufacturer is crucial to get high yields, quality, and timely delivery for prototyping and volume production. This article provides a comprehensive list of the top 18 HDI PCB manufacturers across the globe along with a framework for comparing their capabilities and selecting the optimum partner.
HDI PCB Products

Ipad 3rd-order HDI board

3rd-order HDI board

3rd-order 5G IoT HDI PCB

4th-order HDI buried/blind via board

Semiconductor test 4th-order HDI board

Automotive communication 2nd-order HDI board

10-layer 2nd-order HDI board

Mobile phone 3rd-order HDI board

Industrial control 5th-order HDI board
Manufacturing Capability
Feature | RAYMING ´s HDI technical specification |
Number of layers | 4 – 32 layers standard, 56 layers advanced |
Technology highlights | Multilayer boards with a higher connection pad density than standard boards, with finer lines/spaces, smaller via holes and capture pads allowing microvias to only penetrate select layers and also be placed in surface pads. |
HDI builds | 1+N+1, 2+N+2, 3+N+3,4+N+4, any layer / ELIC, Ultra HDI in R&D |
Materials | FR4 standard, FR4 high performance, Halogen free FR4, Rogers |
Copper weights (finished) | 18μm – 70μm |
Minimum track and gap | 0.075mm / 0.075mm |
PCB thickness | 0.40mm – 6.50mm |
Maxmimum dimensions | 610mm x 450mm; dependant upon laser drilling machine |
Surface finishes available | OSP, ENIG, Immersion tin, Immersion silver, Electrolytic gold, Gold fingers |
Minimum mechanical drill | 0.15mm |
Minimum laser drill | 0.10mm standard, 0.075mm advanced |
HDI Stack-Up Types
HDI PCB (1+N+1): Simplest HDI
- This structure of HDI PCB contains 1 “build-up” of high-density interconnection layers, suitable for BGA with lower I/O counts.
- It has fine lines, microvia and registration technologies capable of 0.4 mm ball pitch, excellent mounting stability and reliability, and may contain copper filled via.
- Applications: Cell phone, MP3 Player, GPS, Memory Card.
Fig.1: HDI PCB (1+N+1)

HDI PCB (2+N+2): Moderate Complex HDI
- This structure of HDI PCB contains 2 or more “build-up” of high-density interconnection layers; microvias on different layers can be staggered or stacked; Copper filled stacked microvia structures are commonly seen in challenging designs that demand high level signal transmission performance.
- These are suitable for BGA with smaller ball pitch and higher I/O counts and can be used to increase routing density in a complicated design while maintaining a thin finished board thickness.
- Applications: Cell phone, PDA, game console, portable video recording devices.
Fig.2: HDI PCB (2+N+2)

ELIC (Every Layer Interconnection): Most Complex HDI
- In this HDI PCB structure, all the layers are high-density interconnection layers which allow the conductors on any layer of the PCB to be interconnected freely with copper filled stacked microvia structures.
- This provides a reliable interconnect solution for highly complex large pin-count devices, such as CPU and GPU chips utilized on handheld and mobile devices while producing superior electrical characteristics.
- Applications: Cell phone, ultra-mobile PC, MP3, GPS, Memory cards, small computer devices.
Fig.3: ELIC (Every Layer Interconnection)

Varieties of Via/Microvia Designs
Vias/Microvias Stacked
This design uses microvias on the external layers of a board which are connected by a buried via through the interior layers of the board. The buried microvias are filled with copper.

Vias/Microvias Staggered
In this design, the external layer microvias are offset from one another.

Microvias Stepped
This design utilizes blind microvias of different diameters. It is not necessary to fill the first level of the blind holes with copper.

Vias in PAD
These vias are used to assemble components with very fine pitch such as Blind Grid Arrays (BGAs) or Surface Mount Devices (SMDs)) onto the same drilled pads. The buried hole is filled with epoxy resins or copper, then capped with copper.

Design Guidelines
The IPC-2221A/IPC-2222 design guidelines recommend a maximum aspect ratio of 6:1 to 8:1 for through-hole vias, where the aspect ratio is the ratio of hole depth to drill diameter. For a 1.60 mm thick PCB, a minimum drill diameter of 0.25 mm is also recommended. These parameters are suitable for production and are endorsed by RAYPCB, especially for high IPC Class 3 reliability requirements. Due to reliability concerns, the via pad size and hole diameter cannot be arbitrarily reduced. Following IPC-2221A guidelines results in a minimum pad size of 0.55–0.60 mm.
If the overall complexity allows it, a design with only through hole vias (i.e. without microvias) can be used with an IPC conform standard-pad size of 0.60 mm.
This is hardly feasible for Fine Pitch BGA components. If for such features the aspect ratio is too critical or the drill diameter is too small then reliability problems threaten. Due to different expansion coefficients of copper and FR4 material the barrels of the vias could crack all too soon, either during multiple lead free solder processes or at the latest by reliability tests.
If there is not enough space for a suitable via pad size, the much smaller microvias should be used. Microvias can be used up to a drill hole depth of approx. 100 µm and due to their short barrel they do not have any problems with different expansions. For this reason, microvias are more reliable than small through hole vias as a general rule.
For 0.80 mm pitch BGAs and PCBs of not too high complexity (max. thickness 1.80 mm, max. 12 layers) it is possible to use through hole vias. In order to achieve this the via pad size has to be reduced to 0.50 mm. Using such a pad size a reliable production is possible with limited manufacturing tolerances.
Microvia solutions are generally recommended and for complex boards or for complex BGA components with a high number of connected pins they are absolutely necessary.
Variant 2: Microvias connected with dogbones provide a planar surface for solder pads since the microvias are not placed within the BGA pads. However, routing tracks between pads on the outer layer are difficult with this approach.
Variant 3: Via-in-pad is the most commonly used method, allowing full utilization of outer layers for routing. While microvia dimples can increase the risk of voiding during soldering, this can be controlled with appropriate soldering conditions. In some cases, an additional microvia filling process can eliminate dimples and reduce voiding risk, but it incurs extra costs.
Combinations of these three variants are also possible.
With 0.75 mm pitch BGAs a sufficient pad size for through hole vias is hardly feasible within the BGA area. In order to ensure reliability, RAYPCB recommends using microvias for such components. In this way standard parameters for track widths, spacing, pad sizes and solder mask clearances can be utilised.
For 0.65 mm pitch BGAs microvias are definitely required. The track width in the BGA area may need to be reduced to 90 µm, or in rare cases even less than this. This depends on the BGA pad size used.
With Variant 1 fine line structures will definitely be required for a 0.50 mm pitch BGA, we recommend 75 µm (3 mil). It will also be necessary to decrease the microvia pad size, at least on the inner layers, to 275 µm. For 75 µm fine line structures the final copper thickness on the surface is limited to approximately 25 µm.
RAYPCB recommends variant 1 described above, without tracks between the solder pads on the outer layer. This avoids the need to use fine line structures on the outer layers.
Variant 2 gives the advantage of a planar surface (lower risk of voiding), but with a reduced solder pad size.
With variant 3, 75 µm structures are needed on the outer layer as well. This increases the production effort and the production costs. Moreover, the solder mask clearance has to be reduced to 35 µm. This variant could probably help to save one microvia layer. Generally the number of the microvia layers required, and therefore the kind of stack-up, depends on the complexity of the component.
Microvias could also be of use for QFP components with a 0.50 mm and more particularly with a 0.40 mm pitch. If the amount of space available permits, microvias can be placed outside of the solder pads using standard pad sizes. If the routing area is not large enough to allow this, then a microvia pad can be set on top of the narrower solder pad.
The fact that a minimum solder mask web width of not less than 70 µm is used must be taken into consideration. With a usual solder pad width of 200 µm it is also possible for 0.40 mm pitch QFPs to have a solder mask web between all solder pads.
When dealing with a 0.40 mm pitch BGA it is possible to utilise stacked microvias in order to avoid fine line structures below 75 µm. There are, however, additional costs involved with this, as the microvias on the inner layers have to be filled and a more complex stack-up may be necessary. But in this way 0.40 mm pitch BGAs can be routed using well established technologies.
The kind of stack-up and the number of microvia layers required depends on the complexity of the component. As with all other BGA components we strongly recommend the use of Non Solder Mask Defined pads for 0.40 mm pitch BGAs, particularly due to the high mechanical stability of such a solder joint.













Advantage of HDI Technology
Why HDI circuit board?
Why is there even a separate category of board technology called HDI? Well, when the lines get smaller than 65 microns (2.559 mils), the ability to etch your trace and space is diminished. You can’t really use a traditional etching process. For example, typical etching on a standard board allows for a very thick resist along with standard imaging on an LDI machine and you essentially have plenty of space for any tolerances needed to etch those spaces. In a microelectronic environment, you don’t have any of those leeways. The features are so close together that traditional etching processes don’t work.
HDI technology is the best choice for board designers when they require a higher density of components. So what makes HDI different from the standard board? Mainly three things:
- Microvias replacing through-holes in higher component density areas of the circuit board
- Layer stack-up alternatives to accommodate microvias
- Arranging vias to improve routing
#1 Microvias replacing through-hole vias – Why microvias for HDI?
HDI uses microvias instead of through-hole vias where higher precision is required. Laser drilled microvias can be used up to a drill hole depth of approx 100µm. Since microvias have a short barrel they do not face problems with different CTE (coefficient of thermal expansion) values of substrate and copper. That’s why microvias are more suitable than through-hole vias.
The best practice for designing an efficient HDI is to replace the most common vias (blind, buried, or through-holes) with microvias. Move the most commonly used layers (Ex: GND or PWR) to the top of the stack-up if they don’t have components and traces on them (GND and PWR planes need to be solid and unbroken). This stack-up arrangement can either eliminate the vias required or allow to replace the through-holes with microvias. As the microvias don’t go throughout the thickness of the board, this provides more space on the other layers. Hence, this practice can improve the routing density of the inner layer and reduce the number of signal layers.
#2 Layer stack-up alternatives to eliminate through-hole vias
Different stack-up arrangements are used in the HDI structure to reduce the number of through-holes and the number of inner layers. The ground and power planes are the most used layers to drill vias. HDI PCB designers can reduce the number of stack-ups by placing these layers at the top of the stack-up, say layers 2 and 3. The top and bottom layers are normally used for component placement.
Thin dielectric layers less than 0.005 inches are used to separate GND and PWR planes. This provides a low power supply impedance and also enables the use of ‘skip vias’ from layer 1 to layer 3.

#3 Arranging vias to improve routing
Proper arrangement of vias is crucial in HDI board designing. The arrangements aim at providing better signal integrity and improving routing space in the inner layers. Here’s a depiction of stacked vias:
Stacked vias
Fine-pitch BGAs create a necessary complication with HDI where the design rules are chosen to not provide clearance for staggered blind vias. The stacking of two microvias or placing a microvia on top of the buried via is needed when this situation arises.

Boulevards created by via placement
Blind vias are arranged to form a boulevard structure. Boulevard formation can reduce the total number of power layers and doubles up the routing space.

These structures can be created by skip vias, multiple buildup, or sequentially laminated, and laminated vias. It is also used for routing of high-speed critical nets using only the cross-over from horizontal to the vertical connection of small and low inductance blind vias.
Manufacturing Process
RAYPCB ensures high-quality PCB production by using customer-supplied Gerber data to generate precise manufacturing instructions, with engineers verifying requirements and defining process steps. Materials are sourced from approved suppliers, stored in controlled environments, and traced back to manufacturing batches for full traceability. Dedicated pre-production engineers (PPEs), trained by RAYPCB, handle data securely and ensure data integrity throughout the process. RAYPCB only uses internationally recognized base materials, rejecting unknown or local brands, and requires their approval for any changes in the production process.
The circuitry undergoes Automatic Optical Inspection (AOI) to detect any defects, with trained inspectors verifying anomalies. RAYPCB prohibits repair of open circuits to ensure reliability and signal integrity. All PCBs are tested using RAYPCB-approved equipment, ensuring high-quality, defect-free products.
In the PCB production process, inner layers are coated with an oxide layer, then stacked together with prepreg to provide insulation between the layers. Copper foil is added to the top and bottom of the stack. The lamination process uses precise temperature, pressure, and timing to cure the resin in the prepreg, bonding the layers into a solid multilayer panel.
RAYPCB ensures high quality by only allowing factories to use materials that comply with IPC-4101 standards, specifically table 3-7, class B/L for maximum thickness and class D for minimum thickness of the dielectric.
RAYPCB ensures high-quality results by using only RAYPCB-approved equipment, which provides excellent performance and positional accuracy for drilling.
The PCB laser drilling process uses a focused laser beam, typically CO2 or UV, to create holes in the PCB, which are then plated to form vias. The laser beam ablates the material, and the recoil pressure from the fast-heating laser ejects excess molten material, typically eliminating the need for additional cleaning.
Designing for laser drilling involves several considerations:
- Hole Size: The laser beam's spot size determines the hole diameter, and the exposure time determines the hole depth.
- Hole Types: Laser drilling can be used for microvias, stacked vias, and staggered vias, with no layer limitation, as the holes are created during a single lamination.
- Material Types: Prepregs used in laser drilling must be compatible with the process, as not all prepregs are laser-drillable.
Typical laser-drilled microvias have a maximum depth of 10 mil with a 1:1 aspect ratio, and hole sizes can be as small as 2 mil. The precision of hole location is much higher compared to mechanical drilling. However, these specifications can vary based on the equipment used, so it's important to consult with the manufacturer for their specific limits on aspect ratio, hole size, and depth.
RAYPCB ensures quality and consistency by having agreements with factories on the specific chemistry to be used during the plating process.
The process for defining the circuitry on the outer layers of a PCB is similar to the inner layer image transfer, with the key difference being the selective removal of dry film to define areas for copper plating. Additional copper is then deposited in areas without dry film to meet either RAYMING's requirement of an average 25μm thickness through the hole or the customer's specific surface thickness preferences. Tin is applied to protect the plated copper.
The Strip Etch Strip process involves removing the blue dry film, etching away unwanted copper (protected by tin), and chemically removing the tin to expose the final circuitry.
RAYPCB standardizes through-hole plating to a nominal thickness of 25μm, which meets IPC class 3 specifications. This provides 25% more copper than IPC class 2, ensuring greater reliability for the via structure and improved z-axis expansion performance. Additionally, all PCBs are tested using RAYPCB-approved equipment, with no track welding or open circuit repair allowed, enhancing reliability and preserving signal integrity.
RAYPCB defines soldermask thickness, with specific measurements for different areas: ≥5μm on the knee of the track and 10-30μm on the surface, depending on copper thickness. This ensures improved electrical insulation and resilience against chemical or mechanical forces. The varying thicknesses provide more robust coverage, enhancing durability. With 70% soldermask fill on type VI via holes, RAYPCB reduces the risk of rejection during assembly. RAYPCB has also established agreed-upon brands and types of soldermasks for use.
RAYPCB has specified approved inks and established a process order to ensure that the ENIG (Electroless Nickel Immersion Gold) process does not react with the inks, preventing discoloration of the deposited legend ink.
RAYPCB ensures that the finishes and chemistry brands used in its factories adhere to strict quality standards. Any changes to the chemistry go through a comprehensive qualification process, which includes regular monitoring of the production process, quality control, and reliability tests. This monitoring includes checking chemistry values, ensuring application thicknesses remain within the specified range, and conducting solderability tests according to IPC standardized methods.
RAYPCB uses approved equipment for profiling, ensuring the best performance, including high positional accuracy. If no specific tolerances are provided in the procurement documentation, default tolerances are applied to all designs.
The PCBs undergo a comprehensive electrical test and are visually inspected by RAYPCB-approved inspectors to meet acceptance criteria. Automated Visual Inspection (AVI) is also used, which compares images to detect discrepancies or concerns automatically. While AVI is essential for inspecting larger quantities, the skill of the inspector is crucial for accurate assessment. Additionally, all orders are fully inspected, including dimensional checks and solderability tests.
Each PCB is inspected against over 100 points defined in the RAYPCB product specification, as well as any customer-specific requirements, to ensure alignment with the acceptance criteria. Every batch undergoes a full evaluation before shipment to guarantee the highest quality standards. RAYPCB's onsite QC teams oversee the verification processes. Track welding or open circuit repairs are not permitted.
Both inner and outer packages should feature RAYPCB labels. After wrapping, the boards are boxed and shipped using the requested mode of transport.
RAYPCB requires ionic contamination levels of the final PCBs to be below 0.8μg/cm² sodium chloride equivalents for Non-HASL finishes and 1.0μg/cm² for HASL finishes, which exceeds IPC's standard requirements. Packing materials, desiccants, Humidity Indication Cards, date codes, lot codes, and the quantity of PCBs or panels per sealed pack must all adhere to RAYPCB's Packaging and Labeling Instructions.

Introduction
High density interconnect (HDI) PCBs enable denser routing, finer lines and spaces, smaller vias, and more layers than conventional PCBs. They are essential for miniaturized and high performance electronics like smartphones, wearables, IoT devices, automotive electronics, and medical devices.
Selecting the right HDI PCB manufacturer is crucial to get high yields, quality, and timely delivery for prototyping and volume production. This article provides a comprehensive list of the top 18 HDI PCB manufacturers across the globe along with a framework for comparing their capabilities and selecting the optimum partner.
Overview of HDI PCBs
HDI refers to the use of microvias (smaller than traditional vias) to interconnect layers in a PCB. This allows greater routing density. Some key features:
- Trace/space: ≤ 100 μm (3.9 mils)
- Microvias: ≤ 150 μm with ≥ 20:1 diameter to hole ratio
- Thin dielectric layers: ≤ 60 μm
- More layers: > 10 layers
- Finer pad geometries
- Tighter pitch components: 0201, 01005 discretes, BGAs
Benefits of HDI technology:
- Miniaturization – More compact PCBs
- Higher speeds – Tight impedance control
- Routing channels – Solve high density routing
- Layer count – Complex designs with 30+ layers
- Higher component densities
- Noise isolation – Separate analog and digital
HDI PCBs require specialized manufacturing processes and equipment. Not all standard PCB manufacturers have HDI capabilities.
Top 18 HDI PCB Manufacturers
1. RayMing Technology
Rayming is 18 years HDI PCB manufacturer,
HDI PCB Manufacturing Capabiltiy : 1+N+1, 2+N+2, 3+N+3,4+N+4, any layer in R&D.

Founded in 2005 and headquartered in Shenzhen, China, RayMing has established itself as a leading manufacturer of HDI, rigid-flex, and specialized PCBs. Some key facts:
- 7 manufacturing sites across China
- Employs over 5000 staff
- ISO 9001, ISO 14001, ISO 45001 certified
- IATF 16949 certified facilities
- Reliability testing – IST, HAST, thermal shock/cycling
RayMing provides a one-stop shop from design support and quick-turn prototyping to high volume manufacturing of HDI, rigid-flex, aluminum, and RF PCBs. They serve customers globally across telecom, auto, industrial, medical, aerospace, and instrumentation sectors. Known for technical expertise at solving complex PCBs using HDI, buried/blind vias, and advanced multilayering.

2. TTM Technologies
TTM Technologies is a leading PCB manufacturer with revenues of $2.2 billion and 16,000+ employees worldwide. Their offerings include:
- HDI layers: >30 layer
- Line width/spacing: 3/3 μm
- Microvias: 80 μm, 60 μm capable
- Via in pad, buried and stacked vias
- Sequential lamination
- Any-layer-HDI
TTM utilizes advanced processes like modified semi-additive (MSAP) to achieve high yields on fine line HDI and rigid-flex PCBs for smartphones, networking gear, aerospace, defense, and automotive applications.
3. AT&S
AT&S is Europe’s largest PCB manufacturer and a leading global producer of HDI boards and IC substrates. The Austria-based company operates plants in India, China, Korea, and Austria.
Key capabilities for HDI PCBs:
- Trace/space: ≤ 5/5 μm
- Microvias: 50 μm
- Laser drilling down to 15 μm diameter
- Build-up layer on both sides
- RDL layers on IC substrates
- Flip chip and wafer level packaging
AT&S focuses on high-end PCB technologies for applications like 5G equipment, automotive radar, and advanced driver assist systems (ADAS). Other areas of expertise include automotive, industrial, and medical PCBs.

4. Tripod Technology
Tripod Technology is one of the largest PCB manufacturers in Taiwan with revenues of over $1 billion. The company has HDI capabilities across multiple facilities:
- Build-up layers: Max 36 layers
- Line width/space: 3/3 μm
- Thickness tolerance: ±10%
- Microvias: 80 μm, 70 μm capable
- Pad size: 70 μm minimum
Tripod specializes in producing ultra-thin, high-precision HDI boards using MSAP for customers serving the communications, networking, automotive electronics, and consumer wearables segments.
5. Unimicron Technology
Headquartered in Taiwan, Unimicron is a global leader in HDI substrates for mobile chips, RF PCBs, IC substrates, and rigid-flex PCBs used in smartphones, laptops, smartphones, wireless gear, automotive infotainment, and portable electronics.
Unimicron operates numerous advanced HDI facilities:
- Line width/space: 2/2 μm
- Microvias: 60 μm
- Stacked microvias
- Thin core handling down to 25 μm
- Plated through holes (PTH): 150 μm
- High TG materials
- Sequential lamination -ALIVH (any layer interstitial vias)
Known for expertise in densely packed HDI flex-rigid boards using staggered microvias for wearables and mobile devices.
6. Zhen Ding Tech
Zhen Ding Tech is a major flexible circuit board manufacturer headquartered in Taiwan with over $2 billion in revenues. Zhen Ding has ramped up investments in HDI and substrate production over the past decade. They provide:
- Over 36 layers
- Blind and buried vias
- Microvias: 60 μm
- Thin laminates down to 12.5 μm
- Flex-on-flex multilayers
- Flexible substrates
ZD Tech produces billions of HDI PCBs annually for automotive electronics, next-gen smartphones, AR/VR devices, and advanced chip packaging. Other capabilities cover chip-scale packaging and wafer level processes.

7. Ibiden
Japan based Ibiden has over $5 billion in revenues and manufacturing sites in Japan, Malaysia, Singapore, Germany, and USA. It is a major supplier of build-up MLBs and HDI packaging substrates to semiconductor firms.
Key HDI capabilities include:
- Build-up layers: >20 layers
- Blind/buried vias
- Microvias down to 40μm
- Copper filled vias
- Laser via drilling at 50 μm
- Thin cores up to 35 μm
- Flexible multilayers
- High density chip packaging
Ibiden focuses on cutting-edge PCB technologies for 5G infrastructure, artificial intelligence, HPC, automotive, aerospace applications.
8. Samsung Electro-Mechanics
Samsung Electro-Mechanics is the PCB manufacturing division of the Korean electronics giant Samsung Group. While best known for multilayer boards for smartphones, Samsung has advanced HDI PCB capabilities:
- Build-up layers: 18~36 layers
- Line/space: 2/2 μm
- Microvias: 50 μm
- Interposers
- Rigid-flex
- High layer FC substrates
- IC substrates with >700 IOs
SEM’s phased investment of over $600 million in HDI facilities provides boards and substrates for Samsung’s IT equipment, mobile processors, and other component businesses.
HDI any-layer connect printed circuit boards are the next technological enhancement of HDI microvia PCBs: all the electrical connections between the individual layers consist of laser-drilled microvias. The main advantage of this technology is that all the layers can be freely interconnected. To produce these HDI PCBs, RayMing uses laser-drilled microvias electroplated with copper.

9. Compeq Manufacturing
Compeq Manufacturing is a major PCB producer headquartered in Taiwan with plants in China/Vietnam serving high-end networking, computing, and communications customers.
Their advanced HDI plant offers:
- Build-up layers: >12 layers
- Line/space: 2/2 μm
- Microvias: 60 μm
- Stacked microvias
- Blind/buried vias
- Thin cores down to 35 μm
- Rigid-flex
Compeq is a key supplier of high layer count boards for data center servers and networking infrastructure demanding leading edge PCB technologies.
10. Wus Printed Circuit
Wus Printed Circuit is a public Chinese PCB manufacturer with annual revenues of over $1 billion. Their HDI capabilities include:
- Build-up layers: As high as 36 layers
- Line/Space: 3/3 μm
- Microvias: 60 μm
- Copper filled vias
- Via in Pad (VIP)
- Thin cores down to 35 μm
Wus uses laser direct imaging to produce high density HDI and SLP substrates for smartphone APs, laptops, automotive electronics, base stations, and data center hardware.

11. Shenzhen Kinwong
Founded in 1992, Kinwong is one of the largest PCB producers in China with global sales exceeding $800 million across seven plants. Kinwong has invested in advanced HDI lines:
- Build-up layers: >20 layers
- Line/space: 2/2 μm
- Microvias: 60 μm
- Thin cores down to 25 μm
- Laser microvia drilling
Kinwong supplies multilayer boards to top telecommunications, industrial electronics, auto infotainment, smartphone, and wearables OEMs.
12. Dynamic Electronics
Dynamic Electronics is a manufacturer of HDI, rigid-flex, and RF PCBs based in Thailand. They offer:
- Build-up layers: Up to 20 layers
- Line/space down to 3/3 μm
- Microvias: 80 μm, 65 μm
- Blind/buried vias
- Flexible multilayering
- Aluminum on flex
Dynamic uses modified semi-additive and subtractive processes to produce complex HDI. Their key end markets include aerospace, defense, industrial, and medical applications.
13. CMK Corporation
CMK Corporation is a Japanese PCB manufacturer specializing in IC substrates, fine pitch boards, and 2.5/3D packages.
Their HDI capabilities cover:
- Build-up layers: >20 layers
- Line/space: 5/5 μm
- Microvias: 60 μm
- Thin cores down to 50 μm
- Blind/buried vias
- Flexible multilayers
- Flip chip bonding
CMK focuses primarily on HDI boards for semiconductor IC packaging and high density wire bonding.
14. Nan Ya PCB
Nan Ya PCB is a Taiwan based manufacturer of laminates, prepregs, copper clad laminates. Its PCB division offers advanced HDI boards:
- Build-up layers: >10 layers
- Lines/spaces: 3/3 mils (capable of 2/2 μm)
- Microvias: 80 μm and below
- Copper filled vias
- Blind/buried vias
- Thin cores
Nan Ya produces rigid, flex, and rigid-flex HDI PCBs for automotive electronics, servers, base stations, routers, switches, and other networking gear.
15. Shinko Electric
Headquartered in Japan, Shinko manufactures HDI PCBs, IC substrates, and semiconductor packages. They provide:
- Build-up layers: Up to 20 layers
- Line/space: As tight as 15/15 μm
- Microvias: 60 μm
- Thin cores down to 30 μm
- Laser drilling at 35 μm
- Blind and buried vias
Shinko services customers in computing, communications infrastructure, automotive infotainment and ADAS applications.

16. Fujikura
Fujikura is a Japanese manufacturer of flexible printed circuits with revenues exceeding $1.3 billion. Their flexible HDI capabilities include:
- Build-up layers: 6 to 8 layers
- Blind vias and microvias
- Flex-on-flex multilayering
- Rigid-flex integration
- Roll-to-roll mass lamination
Fujikura flex circuits find applications in consumer electronics, automobiles, robotics, medical devices. Their expertise lies in high-mix, flexible HDI production.
17. Flexium Interconnect
Flexium is a leading Taiwanese manufacturer of flexible PCBs with revenues of approximately $1 billion. They possess advanced flex HDI manufacturing capabilities:
- Build-up layers: 8 layers
- Blind vias
- Thin flexible multilayering
- Roll-to-roll processing
- Laser via ablation
Flexium supplies flex and rigid-flex boards for dynamic flexing applications in smartphones, laptops, consumer electronics, wearables, VR/AR devices.
18. Flex International
Flex International provides comprehensive flex PCB fabrication and assembly. Their flexible HDI capabilities include:
- Build-up layers: 6 to 10 layers
- Blind and buried vias
- Laser microvias down to 25 μm
- Thin cores down to 25 μm
- Flex-rigid-flex integration
- Quick turnaround prototypes
Flex International produces custom flexible circuits boards for medical, industrial, aerospace, and defense industry customers.
Comparing HDI PCB Manufacturers
Here are some key factors to consider when selecting an HDI partner:
Technical Capabilities
- Finest line width/spacing – 2 μm or lower is preferred
- Microvia size – 50 μm to 80 μm range
- Number of HDI build-up layers – >20 layers ideal
- Thin core handling – 25 μm to 35 μm range
- Laser drilling diameters – Below 50 μm
- Blind and buried vias for dense interconnects
- Stacked or staggered microvias
Quality & Reliability
- IPC 6012 Class 3 and Class 3A certification for HDI
- Robust quality processes – AOI, test, inspection, statistical process control
- Reliability testing – IST, HAST, drop/shock/vibration
Volume Production
- Monthly capacity – Number of panels per month
- Consistent on-time delivery metrics
- Years of experience with mass HDI production
Customer Service
- Technical expertise providing layout reviews and DFM feedback
- Response time for quotations, samples, inquiries
- Supply chain transparency and reporting
- Customer reviews and testimonials
Cost
- HDI pricing – may vary based on complexity, layer count
- NRE charges for prototyping
- Budgetary estimates before design finalization
Location
- Production sites close to key customers
- Global footprint for production redundancy
Carefully evaluating manufacturers against these criteria simplifies selection of the ideal HDI partner.
Conclusion

HDI PCB technology enables miniaturized electronics design through high density interconnects, fine features, and thin materials. As products become thinner and lighter, HDI provides the means to pack more functionality and components into tight spaces. Partnering with specialized manufacturers that have invested in advanced HDI capabilities and processes is crucial to realize the benefits of next-gen PCB technologies. This article provided an overview of the top 18 HDI PCB manufacturers globally and a framework to match specific product needs with the right manufacturing partner. The key is early supplier engagement to understand capabilities and limitations before finalizing designs. Investing upfront in DFM and manufacturability will ensure high yields and repeatable quality when transitioning to volume HDI production.
FAQ
What are some key differences between HDI and conventional PCBs?
HDI PCBs use smaller microvias rather than traditional vias to interconnect layers. They allow finer traces and spaces, thinner dielectric materials, higher layer counts, and greater component densities versus standard PCBs.
What are the typical applications for HDI PCBs?
HDI PCBs are commonly used in space constrained and high performance products like smartphones, wearables, medical devices, auto electronics, aerospace avionics, 5G infrastructure, and other advanced electronics.
What are the typical lead times for prototype vs production HDI PCBs?
HDI PCB prototype lead times range from 24 hours to 2 weeks depending on complexity. Volume production lead times are usually around 4 to 8 weeks once the design is finalized.
Does HDI improve signal speeds compared to conventional PCBs?
Yes, the thinner dielectrics, dense interconnects, and impedance control offered by HDI technology allows faster signal propagation which improves high speed capabilities.
What are the main challenges in manufacturing HDI PCBs?
Tight process controls and special equipment are required to produce fine features and thin materials consistently. Handling thin cores without distortion and high yields on microvias require considerable expertise. Testing and inspection regimes must also validate the high density interconnects across layers.