The Printed circuit board holds an integral part in various devices as seen in our daily living. It ranges from portable electronic devices to heavy equipment and industrial machines. PCBs are also present in consumer electronics and communication devices.
Modern PCB design are complex. Various shapes with different base materials make up the designs. PCBs could be flexible or rigid. The components wired together differentiate the types. It is to carry out specific requirements on the board. Early PCBs were either single or double layers. They are functional in simple computation and automation devices.
Currently, PCBs are advanced in design. There are multilayer, Rigid and flexible PCB designs. They are present in smartphones and biomedical instruments. They are also present in smart watches, motherboards, and crypto currency mining devices.
Furthermore, a multilayer PCB starts from 3 conductive layers to 40 layers PCB. The copper plated hole connects all the layers. The top and base layers are similar to double-sided PCB. However, there are differences. A 26 layer PCB has its layers stacked on both sides of the core.
Also, these via copper-plated holes get compressed to form a single PCB. The electronic elements occupy the base and top layers of the board. Soldering of the surface mount technology could be on either of the sides of the 26 layer PCB design.
What is a 26 Layer PCB?
The 26 layer PCB is a multilayer design. It could be a rigid multilayer PCB, flexible multilayer, or a mix of both. This article will examine 26 layer PCB as a rigid-flex multilayer PCB.
In addition, the 26 layer PCB being a rigid-flex PCB, merges the foremost traits of the rigid and flexible PCBs. Thus manufacturers could easily install the design in minimal spaces. Maneuvering is easier on the board during installation through its flexibility.
A 26 layer PCB is a mix of both rigid and flexible circuits. Furthermore, this design provides results and applications. It also serves as a substitution for rigid PCBs. Also, its usage exceeds electronic devices. It also includes a broad range of industrial and electrical applications. High graded aircraft-mounted weapon guiding system also uses the 26 layer PCB design.
Aerospace electronic manufacturing devices for the military also adopted its usage. There are guiding rules for a rigid-flex PCB design.
Design Guidelines for 26 Layer PCBs
Designing a rigid-flex PCB that meets the standard requires some basic guiding principles. These include the following:
Layer Count Review: 26 Layer PCBs comprise 26 alternating layers. They consist of rigid and flexible materials. Reviewing the number of layers required for its intended use is very crucial. Then consultation with the manufacturer to ensure the layers are appropriate for the requirement takes place.
Heat Sinking Capacity: Heat evaporates as current moves through the electronic device. Evaporated heat depends on factors like power, device characteristics, and PCB design. An increase in heat could lead to potential damage to the device. The heat-sinking capacity of the device protects the device for optimum output.
Material Layup: Material layup is crucial to designing a 26 layer board. It impacts the performance, cost, and manufacturing ability of the PCB. Therefore, a proper material layup needs to cover the under listed areas in the design
- Impedance control
- Lead-free assembly agreement
- Appropriate materials
- Mechanical consideration
- The slightest bend radii required
All the layers in the 26 layer PCB have to use a similar layup. Their thicknesses and other rules guiding their designs need proper attention. Keeping to these guiding principles will help reduce manufacturing challenges.
Manufacturing Process for 26 Layer PCB
Fabricating a rigid-flex PCB such as a 26 layer board is time demanding and laborious. Several steps with extreme accuracy will help deliver a PCB with high integrity. Also, the efficiency of the final design could fail if any of the flexible elements in the board is not well handled.
The steps involved are as follows:
Base material Preparation: This is the first required step in the process. The laminate on the board has to go through the cleaning process. The laminates contain a copper layer with adhesives. Cleaning becomes crucial due to the oxidation protection in the copper. Failure to clean the coating on the copper hinders the process.
Generating Circuit Pattern: The circuit pattern has two operating methods that include screen printing and Photo imaging. Screen printing deals with depositing the circuit pattern into the surface laminate. Its total density is at 4-50 microns.
Photo Imaging deals with outlining the circuit traces on the laminate. It is the oldest but popular technique for generating the circuit pattern. The placement of a photoresist film with the desired circuitry near the laminate is also required.
Etching of the Circuit Pattern: The producer dips the laminate in an etch bath. More so, spraying the laminate with etchant solution after generating a circuit pattern is also an option.
Drilling Process: This drilling process creates holes, pads, and vias on the board.
Through-hole Plating: This requires extreme care in the rigid-flex PCB manufacturing process. Connections between a layer and another are possible through the deposited copper.
- Applying Cover lay
- Cutting out Flex
- Electrical Testing and Verification
Applications for 26 Layer PCB
The unique attribute of combining rigid and flexible features increased the acceptance level. Also, it starts from small gadgets to complex devices.
The following rigid-flex PCB applications consist/ of the 26 layer board
- Barcode scanners
- Smart Jackets
- CT scans
- Cell Phones
- ABS sensors
- Digital cameras
- Peacemaker
Benefits attached to 26 Layer PCB design
The rigid-flex 26 Layer PCB comes with lots of benefits. The benefits are vital for the end-users and manufacturers. They include:
High-Density Applications: 26 layer PCB is the best design suitable for a high-density device. Its solidity, flexibility, and small space usage enhance the delivery of quality end products.
Accurate Connection: Rigid-flex PCB has a higher stability and polarity feature. Connection becomes easier and well secured with other components. Also, connector components are fewer with each application.
Cost-Effectiveness: Adopting a 26 layer PCB enhances cost efficiency. The production cost of the design is low.
Mechanical Stability: The structure for the multilayer PCB comprises interchanging layers. It has rigid and flexible features. Also, it enhances their stability and flexibility. It also facilitates the easy installation of components in small spaces available.
High-level Vibration Resistance: Electronic elements are in a variety of devices. They are open to a high level of vibration while in use. Thus, devices fabricated with 26 layer PCBs are safe from vibration. A rigid-flex PCB is strongly resistant to vibration and shock.
Other benefits include:
- Non-complex PCB assembly procedure
- Few soldering points that ensure a very high connection integrity
Conclusion
With the evolving technology, electronic designs are getting more complex with time. Manufacturers are dealing with the challenge of how to maximize small space. Meanwhile, the board requires more components. They also desire a high-density design that absorbs the functionality of the device. Furthermore, the double-sided PCB could not fulfill these needs. Thus, the emergence of Multilayer PCB such as 26 Layer PCB designs.
