Multilayer PCB MANUFACTURE

What is multilayer PCB?

Multilayer PCB contains more than two copper layers & substrates in its stackup, which makes it multilayer PCB. Because of its capacity to handle high-density and complicated circuit designs while still keeping a compact form factor, multilayer PCB’s are a best solution for complicated components in modern Electronics applications and products.

The Multilayer PCB's Structure:

Detailed specification of our standard and advanced multilayer rigid PCB capabilities are mentioned in table given below:

OUTER LAYER
DESCRIPTION	STANDARD	ADVANCED
Single / Double Sided	Minimum (7.874 Mils) & Max (314.96 Mils)
Multilayer	Minimum (11.81 Mils) & Max (314.96 Mils)
Bow & Twist	3 to 7/1000

Outer Layers:

The top and bottom conductive layers at which the majority of components are soldered are referred to as the outer layers.

Inner Layers:

There are additional layers of conductive copper that are known as the inner layers. Multilayer printed circuit boards (PCBs) can have several inner layers, including the top and bottom layers.

Prepreg:

The layers of insulating material that are used to separate the inner copper layers are referred to as prepreg. These are layers of fiberglass that have been partially cured and are used to apply the bonding agent between the layers.

Core:

Core works as insulating material, contains epoxy resin fiber glass, there are various types of RF & High speed dielectric substrate which also helps to prevent transmission signals in circuits with reference copper layers.

Vias:

The important purpose of plated Via’s is to make interconnection between two or multiple copper layers. There are different types of VIA’s according to the complexity and application of the PCB.

Through-Hole Vias: Vias that passes through all layers of PCB from top to bottom and giving connection to all layers
Buried Vias: Vias that is buried in inner layers and not shown on outer layers. For example a via from 4th inner layer to 6th, 7th and 8th inner layer of PCB.
Blind Vias: Vias that connect one of the outer layer to any internal layer.
Copper Coin Via’s: Vias filled with copper solid coin are those meant to increase electrical conductivity and thermal performance by means of copper. these are usually applied into technologies which required high power and high speed circuits.
Epoxy filled Vias: Epoxy filled Via’s are also known as non-conductive filled Via’s. This technology is applied to insulate heat and to reduce risk of solder paste wick on SMD pads where Via’s need to be placed.

Stackup of Multilayer PCBs:

When the structure of a multilayer PCB’s are taken into consideration, the arrangement of layers are decided according to design requirements including, ground, power planes and signal layers. Placement of layer are done with careful calculations with regard to signal integrity.

There are following consideration when one is planning layer stackup:

Signal Integrity
EMI/EMC Considerations
Power Distribution
Component Placement and Routing
Thermal Management
Reliability and Long-Term Performance
Mechanical Strength and Durability
Manufacturability and Cost Constraints

Applications of Multilayer PCBs:

Due to their capacity to accommodate circuit designs that are both sophisticated and high-density, multilayer printed circuit boards (PCBs) are utilized extensively across a wide range of sectors. The following is a list of the most prevalent applications and economic sectors in which they are utilized:

Telecommunications
Automotive
Consumer Electronics
Medical Devices
Industrial Automation
Aerospace and Defence
Computing and Data Centers

Our multilayer PCBs capabilities are designed to achieve the demands of todays and upcoming high density interconnect and complex circuit designs while maintaining a compact form factor. We aim to serve telecommunications, automotive, consumer electronics, medical devices, industrial automation, aerospace, defense, or computing & networking.

Our IPC A 600 & IPC A 610 engineering team ensures that every production must meet end user requirement including avoiding crosstalk with controlled impedance traces and with advance capabilities layer stacks from 1L to 60L layers, and critical features like copper coin via’s for enhanced electrical conductivity and thermal performance.