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HDI Printed circuit board: basic features and types

Do you the best and enhanced electrical performance? Are you looking for a lightweight and smaller size PCB? If so, you should go to HDI PCB with modern structures. HDI is the abbreviation of High-density interconnector. A circuit board with a higher wiring density per unit is termed as HDI PCB. It is distinct from the conventional board in structures, weight, and size. HDI PCB offers spaces and finer lines, micro vias and capture pads. It provides a higher connection pad density. You may enhance the electrical performance and size of equipment with HDI. If you want higher layer count and costly laminated boards with micro vias, HDI PCB is the top choice for you.


HDI PCB is designed to meet the special needs of high-speed signals. It has some distinct features which make it different from an ordinary PCB.

Lamination in HDI PCB

AA printed circuit board is used to connect and support electronic components. A high-density PCB has conductive pathways to connect components. Based on PCB types, we use the following types of the lamination process.
Lamination of multiple layer PCBs

The circuit boards with various layers are called multiple layer PCBs. We bond these layers with lamination. You need to subject the internal layers under extreme temperature and pressure. The process is implemented with a photosensitive dry resist with fine imaging. Then PCB is placed under high temperature. Then the pressure is released slowly. The material then cools down. If PCB has two or more subsets then we use a sequential lamination process. A separate process is done to create subsets of the multi-layer PCBs. We use a dry electronic substance between each pair of subsets. After this procedure, the standard manufacturing process is implemented. So the sequential lamination works.
Generally, we distinguish HDI boards by the number of Lamination and the number of laser drilling, for example: 1+N+1, 1+1+N+1+1,2-(N-1)

The mostly used HDI laminates for PCB lamination are PTFE microwave and FR4 mix laminates. and PTFE is different reasons for their popularity. It has consistent dielectric constant, very low electrical consumption, and tight thickness tolerance. Its component material is common due to which this lamination is in common use. You should choose the lamination type which best suits your application. If you want a more suitable consultation, you must contact the manufacturer. It all depends on the circuitry density of your application.

HDI PCB stacked via hole

We use this technology in the design and fabrication of HDI PCB stacked via hole. Sometimes these via holes are staggered via holes. To connect very small diameter micro via we use this technology,such as blind and buried holes. To route fine pitch components. These micro via holes pay an important role in shrinking PCB size. We do not use holes for inserting a component lead or any other reinforcing material. If you want to connect outer surface micro via holes, you need sequential lamination. It is because of a very small drill and aspect ratio requirements on all drills. The process is usually associated with thermal pad technology.

How to choose HDI PCB material

So you are going for HDI PCB. But how to choose the quality material for your HDI PCB is not an easy task, but you may do it. Here is the process. Surely you want to take your PCB to the next level of high performance. It is the basic point of designing an HDI printed circuit. You will have to deal with, micro via, spaces, and finer lines. You will have to work with laser, small capture pads, and micro via. Signal integrity is an important thing to consider. You may go through different types and structures of HDI Stackup but with the laminated and mechanically drilled core. You need to create inner layers, sequential lamination as well as drilled micro via and final through holes with the laser. So ou can choose from the following brands.

Why PCBONLINE is the right manufacturer for you?

PCBONLINE has been in the printed circuit boards market for the last 15 years. The company has vast experience in PCB manufacturing and designing various types of circuit boards. You may order any type of board with premier functionality.

  • We offer free set up and tests. For repeat orders, we offer discounted rates.
  • We receive your formal quotes quickly and process it fast. You will receive a quote soon after your orders.
  • Excellent customer and consumer service with guaranteed high-quality material.
  • The ratio of quality and cost is excellent with us. We give maximum benefits for your investment. The circuit boards will perform up to your expectations.
  • We have modern equipment, a skilled team of engineers and designers. We successfully cater to consumer’s needs.

2. Excellent technical ability to meet the HDI PCB producing requirements.

Feature Capability
Layer count 1~24
HDI Stack up 1+N+1,2+N+2,3+N+3(with copper filling)
Final board thickness 0.15-3.2mm
Aspect Ratio Laser via
Copper thickness 1/3~6oz
Impedance Control Single Ended
+/- 10%
+/- 10%
Line/Space Inner Layer
External Layer
Min Drill Bit size 8mil
Hole size tolerance PTH
Hole Position Tolerance +/-2mil
Profile Tolerance Punching
Solder mask Line to PAD
Warpage 0.5%
Surface Finish HASL(LF HASL)
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"

How to order the HDI PCB