The Importance of PCB Service
Many people don’t realize that the electronics, devices and items they use every day are built upon several internal components which work collaboratively to perform their functions. One of the core pieces is a printed circuit board or PCB.
There are a number of factors that determine how much your pcb service will cost. In this article, we’ll discuss some of the most common ones.
Fabrication
A PCB (printed circuit board) is an electro-mechanical device that holds electronic components together and provides them electrical connections through a unique network of copper traces. They are the backbone of almost all electronic devices, from the simplest to the most complex. Printed circuit boards are also the primary means for testing and debugging electronic systems.
The earliest steps in the fabrication process include preparing the copper and laminate material, imaging, and depanelization. A PCB can have one, two, or six layers of copper interconnect, with the most common being a pcb service single-sided bond. A single-sided bond is an insulating material with metal tracks on one side and holes (vias) on the other to connect the metal tracks to other layers. The holes are either through-hole, blind, or buried vias.
After an engineer reviews a PCB design and gives it clearance, the design moves to the printing stage. Most fab houses run a DFM (design for manufacturing) check before they print the circuit board.
Once the Gerber files have been checked and approved by the engineers, they are transferred to a special printer known as a plotter. This special printer uses a high-resolution technology to create extremely precise films for the intermediate and outer layers of the PCB as well as solder masks and silk screens. The films are on transparent plastic with black ink representing the photos of the specific layer.
Assembly
Choosing the right PCB assembly process can have a significant impact on the manufacturing cost and performance of your electrical device. This is especially true for complex circuit boards that use surface mount technology (SMT). Surface mount components are smaller and more expensive than through-hole components, but they are also easier to integrate into the board. In addition, SMT allows for more component density and smaller overall size.
During the PCB assembly process, your circuit board will undergo a series of inspections to ensure that all the components are properly placed and that all the connections are intact. This can be done manually or by using automated inspection equipment. This step is crucial to ensure that all parts are placed correctly and that the connections between them are strong. In some cases, the circuit board may require rework to fix issues such as faulty solder joints or incorrectly positioned components.
After the inspection, your circuit board will be washed in hot water and blown dry with powered air jets. It will then be reflow soldered using a special no-clean flux, which contains resins and activators pcb custom to make the solder flow more easily and prevent it from oxidizing. This process is also used to solder the through-hole components and non-washable items like pins, connectors, and fuses. The reflow soldering process requires high temperatures, and the circuit board must be carefully inspected to make sure that all the solder is secure.
Testing
After the assembly process, PCBs undergo a series of tests to ensure that they meet quality and functionality standards. This testing process can be as simple as a basic functional test or as complex as a post-assembly failure analysis. This service is important to reduce the risk of expensive repairs and product returns.
The testing process is designed to detect errors in the circuit board, such as open or short circuits. These defects can occur due to a variety of reasons, including poor soldering or incorrect components. In-circuit testing (ICT) is the most accurate way to check a PCB for defects. It uses fixed probes arranged in a pattern that corresponds to the circuit board’s layout. The probes can identify issues like shorts, opens, resistance, and capacitance.
Manufacturers also conduct a wet immersion test to ensure that the boards are durable and can function in harsh environments. The weight of the circuit boards is measured before and after the immersion test. PCBs that show significant weight changes are rejected.
Other tests conducted on PCBs include a copper plating test, which analyzes the thickness and quality of the copper foil. Solderability tests are also performed, which measure how well a board’s surface will accept liquid solder. These tests help prevent problems such as solder joints that are too weak or cracked.
Rework
Rework is a process in PCB assembly that involves identifying issues, preparing the area, removing the components, cleaning the site and re-installing the components using precise soldering techniques. This includes rerouting circuit traces and jumper wires to establish new connections. It also requires careful inspection to ensure proper function and compliance with quality standards.
The rework process involves working with delicate electronic components, which can be very sensitive to damage. Therefore, it is important to follow strict safety procedures when repairing a printed circuit board. This includes wearing anti-static wrist straps, gloves and overalls to prevent electrostatic discharge (ESD).
Moreover, PCB rework requires specialized tools such as desoldering guns, tweezers, multimeters, soldering irons, flux, and magnifying glasses. These tools are used to remove and replace components, repair traces, and make other modifications.
The rework process is particularly important for printed circuit boards with through-hole components. These are components that have leads inserted through holes in the PCB and soldered on the reverse side. In addition, rework is also essential for the assembly of surface mount devices (SMDs). The right PCB company should be able to handle all types of rework, including the most difficult ones such as ball grid arrays. A good rework service will be able to save assembled or bare printed circuit boards by fixing and replacing the defective components. This will also protect the environment by reducing the amount of waste produced.
