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What is 4 layers HDI Rigid-flex PCBs fabrication: Latest Guide 2020


What are Rigid-flex PCBs and 4 layers HDI Rigid-flex PCBs?

4 layers HDI Rigid-flex PCBs suppliers

The base of 4 layers HDI Rigid-flex PCBs actually has come from the Rigid flex PCBs. This blend of HDI technology with rigid-flex PCBs makes them greatly reliable for technology in modern era.

Rigid-flex PCBs are basically printed circuit boards and electronic designers design them with the both,

  1. rigid
  2. and flexible areas.

Hence, this technique makes them ideal solution for an extensive range of applications. The conventional rigid-flex PCB circuits add two or extra conductive layers. And these conductive layers consist of whether rigid or flexible insulation material within each of them.

The external layers be able to contain either bare covers or pads. Electronic designers explain that conductors, which they have planted on the rigid layers. Those conductors have also planted on one as well the other flexible and rigid layers.

This combination of rigid-flex with HDI technology makes these PCBs high reliable for modern day applications. So, designers have designed layers HDI Rigid-flex PCBs to fulfil the requirements of latest market.

Hence, basically HDI rigid-flex PCB with 4 layers are multilayer PCBs. These PCBs contain both flex and rigid layers with electric interconnecting. Moreover, a blend of rigid and flexible layers within only single circuit board generates some unique and special opportunities.

This advanced technology also enables the designers to replace multiple PCBs interrelated with,

  • wires
  • ribbon cables
  • connectors

in order to fabricate a circuit board. On the other hand, it also improves

  • reliability
  • performance
  • also reduce the interconnection cost.

How 4 layers HDI Rigid-flex PCBs make a perfect solution for advanced technology?

Additionally, HDI rigid-flex PCB boards with 4 layers also have capability to,

  • bend
  • twist or fold

to make 4 layers HDI Rigid-flex PCBs, a perfect resolution for upgrading applications. Because they supply all above characteristics with extra quality of tight spaces. And also make use of tight space limitations in third dimension.

Moreover, during last decade, HDI Rigid-flex PCBs with 4 layers have become a preferable design solution for,

  • complicated
  • three-dimensional
  • demands of innovative component of surface mounting.

For what HDI stand in 4 layers HDI Rigid-flex PCBs?

In layers HDI Rigid flex PCBs, HDI stands for High Density Interconnector. It means a circuit board that has a density of higher wiring per unit area. And because of this, it is best in comparison to standard board.

Hence, it is popular as the name of HDI Rigid flex PCBs. HDI Rigid flex PCBs basically have superior quality lines and spaces along with,

  • capture pads
  • minor vias
  • density of greater connection pad.

Basically, HDI boards are among the rapidly growing technologies in PCBs. HDI boards actually hold buried or blind vias. And they often have microvias of .006 or may be less than in diameter.


In fact, layers HDI Rigid flex PCBs contain a density of highest circuitry in comparison of conventional circuit boards.

How 4 layers HDI Rigid-flex PCB make your product more innovative?

HDI rigid flex PCBs with 4 layers supply an extra unique accessory to bring all your innovative thoughts in market. Furthermore, these PCBs also have ability to individualize your products from a great crowd.

Additionally, they also have capability to design the circuitry system in order to fit the devices. While instead of designing a device for the purpose of to fit the printed circuit boards.

Moreover, they can add innovations in your product in the following ways:

  1. Can improve resistance to movement and vibrations with lower weight/mass
  2. As the name describes, layers Rigid flex PCBshave great flexibility
  3. They also allow the rigid board to bend in its desirable applying shape
  4. Basically, they have small package size
  5. You can considerably deform or wrap them as they have great strength of tensile
  6. These PCBs also allow for better compact devices
  7. They have ability of great bendiness
  8. You can bend them up to 360 degrees

What materials electronic designers use in 4 layers HDI Rigid-flex PCBs?

Basically, electronic designers use the following materials in HDI rigid-flex PCBs with 4 layers.


The selection of adhesive actually depends on the needs of customers and the thickness of conductor. Normally general adhesives include:

  • Acrylic
  • Epoxy
  • Pre-preg
  • Adhesiveless base material
  • Pressure sensitive adhesive (PSA)

How 4 layers HDI Rigid-flex PCBs add density in your packaging?

The typical dielectric in flexible circuits is .001 – .002″. And hence make it a natural for,

  • ultra-light
  • ultra-thin packaging.

HDI, Adhesiveless laminates and layers of thin copper also make it perfect for superb technology.

Basically, they have ability to provide you with,

  • smallest
  • thinnest
  • lightest

solutions for your ideal circuit designs. In this way, HDI rigid-flex PCBs with layers add great density within your ideal and perfect packaging.

What are the applications of 4 layers HDI Rigid flex PCBs in various industries?

As we know that there are great uses of HDI Rigid-flex PCBs in various electronic industries.

Moreover, there are two basic structural applications of HDI Rigid-flex PCBs with 4 layers.

These applications are:

  1. Dynamic Flexing Applications
  2. static Application

Dynamic Flexing Applications:

In these situations, area of flex circuit is dynamically flexed for several reasons beyond and above an ordinary installation.

Static Applications:

These are applications where designers need flex circuits in order to install the circuit.

And they are also familiar as flex-to-install or flex-to-fit.

Furthermore, the best features of these PCBs have made them essential for following electronic industries like,

  • communication
  • all computer appliances
  • consumer electronics
  • medical
  • military electronics
  • automotive, etc.

What are the advantages of 4 layers HDI Rigid-flex PCBs?

In fact, there are a lot of advantages of layers HDI Rigid-flex PCBs. We are describing some of them

Flexible Design Options:

4 layers HDI Rigid-flex PCBs

Rigid flex PCBs have ability to meet highly complicated designs. And these complex designs are:

  1. Three to eight-layer combinations
  2. Controlled Impedance
  • Reduced interconnections
  1. Highly complex configurations.

Connection Reliability:

Actually, these PCBs have ability to fix the rigid and flexible cables with great reliability.

Lower Part Count:

In comparison to traditional rigid board, these PCBs of both rigid and flex combinations need fewer interconnections and parts.


Nowadays HDI rigid-flex PCBs with 4 layers have got great fame because they are highly suited for modern day electronics. Their demands in almost all industries are increasing day by day. And basically, there are 3 basic reasons to select them for all electronic devices:

  1. greatly reliable
  2. best for complex designs
  3. low cost.

So, electronic designers are making use of these PCBs for all their complicated applications.

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