How the type designation of the laminate is determined in PCB manufacturing?
In PCB manufacturing, the material of resin, fiber, or cloth used, and the resin-to-cloth ratio determines the type designation of the laminate, such as CEM-1, FR-4, G-10, etc. Thus, the characteristics of the laminate made decide the level at which the laminate is resistant to fire.
Some of the other important characteristics that make the laminate of a PCB highly functional include:
The loss tangent
The dielectric constant
The tensile strength
The glass transition temperature
The shear strength
The Z-axis expansion coefficient
In the manufacturing process, circuit board producers choose different dielectrics to provide the board with diverse insulating values according to its circuit requirements. Thermal expansion is also a vital consideration, particularly with naked die technologies and BGA or ball grid array. However, glass fiber provides the board with the best dimensional stability.
Nowadays, FR-4 is the most commonly used material in PCB manufacturing. Copper-dressed laminate is the board stock with unetched copper on it. With increasing frequencies and decreasing size of the features of the printed circuit board, small non-homogeneities, such as irregular sharing of fiberglass or other fillers, bubbles in the resin matrix, thickness differences, and the related local disparities in the dielectric constant, are adding significance.
In PCB manufacturing, there are some important substrate parameters to be considered. The substrates of a circuit board are generally dielectric composite materials. The composites contain:
A matrix, usually an epoxy resin
Reinforcement, generally a woven, nonwoven, glass fibers, or paper
Addition of filler
Manufacturers use fillers, such as titanate ceramics to increase the dielectric constant of the laminate.
In the process of PCB manufacturing, two major categories of materials are being used for reinforcement namely woven and non-woven materials. Reinforcements that are done with woven materials are considered the most economical option, but they are not suitable for applications that need high frequencies. Although non-woven materials or reinforcements are costly, they are appropriate for some analog or RF applications.
The substrates in printed circuit boards are featured by many key parameters, primarily thermo-mechanical. The materials used for manufacturing a printed circuit board determine the dielectric constant of the substrate. It also counts on the frequency and the dielectric constant and it will decrease with the decreasing frequency.
PCB printing is the final designing process of a PCB, as it involves mounting of all electronic components, circuits, and other features onto the board. Once all the required features are incorporated into the board, it will undergo a quality control process to check its performance, functionality, and electrical conductivity.
All manufacturers will opt for a PCB prototype process before the PCB is sent to the final manufacturing process. With this process, they can spot the missing electric components, faulty tracks and circuits, and other manufacturing imperfections easily. It allows them to make a performance-focused board effectively.
Manufacturers of an LED PCB deliver their boards that are equipped with bulbs of different colors according to the specifications and application needs of users. The color of each LED bulb offers different voltages and lighting characteristics, making the boards suitable for all types of individual and industry applications.
A Rigid Flex PCB offers a bounty of benefits to users. The major benefit is that using these printed circuit boards for interconnections will aid users considerably in eliminating the need for using bulky and awkward connectors. This design feature makes these electronic circuit boards more frivolous than other types of printed circuit boards.
